Offshore energy island single-line looped network power supply system based on underwater caisson energy storage and control method

Abstract

The invention provides an offshore comprehensive energy island power supply system based on a single-line looped network and an underwater caisson drainage energy storage power station and a control method. The offshore comprehensive energy island power supply system comprises a looped network power cable, n offshore new energy DC / DC converters, n platform load DC / AC inverters, n caisson energy storage bidirectional DC / DC converters and a looped network controller, wherein an optical fiber is embedded in the looped network power cable, and the looped network power cable is coaxial with the power cable; the devices are distributed according to ocean geography, and adjacent devices are annularly connected end to end in series through a looped network power cable to form an offshore comprehensive energy island power supply system based on a single-line looped network and an underwater caisson drainage energy storage power station. And the looped network controller is respectively connected with the n on-sea new energy DC / DC converters, the n platform load DC / AC inverters and sub-controllers embedded in the caisson energy storage bidirectional DC / DC converter through optical fibers embedded in a looped network power cable. All devices in the looped network are monitored in real time.

Description

Technical Field

[0001] This invention belongs to the field of offshore power supply, specifically relating to a single-line ring network system and control method for offshore energy islands based on underwater caisson energy storage. Background Technology

[0002] Currently, the country is vigorously developing deep-sea wind power, forming large-scale offshore wind power clusters. However, the instability of wind power leads to fluctuations in wind power transmission, directly affecting energy export and the development of offshore energy islands. Therefore, there is a need to further improve efficient and stable power supply and transmission measures for offshore wind power clusters. In particular, the stable, economical, and reliable energy needs of developing offshore energy islands and offshore oil extraction platforms are urgently required.

[0003] One of the economic advantages is that traditional wind power transmission often uses multi-core submarine cables, and the cost of construction and related materials for these cables increases with voltage levels. Furthermore, while superconducting technology is rapidly developing and its applications are becoming more widespread, the numerous lines required for traditional power supply methods pose significant challenges to the cost and maintenance of superconducting technology.

[0004] Furthermore, the current power supply for offshore oil extraction platforms is mainly generated by diesel engines or natural gas generator sets. However, this has problems such as high energy consumption, high noise, and environmental pollution. There is an urgent need to study an economical, reliable, stable, green, and stable energy alternative. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a single-line ring network system and control method for an offshore energy island based on underwater caisson energy storage. This system constitutes an integrated offshore energy island combining offshore renewable energy generation, a single-line ring network, an offshore working platform, and an underwater caisson drainage energy storage power station. Physically, a single power cable connects the offshore renewable energy generation unit, the offshore working platform, and the underwater caisson drainage energy storage power station in series, forming a power supply system for the integrated offshore energy island consisting of a single-line ring network and the underwater caisson drainage energy storage power station. Because the loads of the offshore renewable energy generation unit and the offshore working platform within the ring network change in real time, the power supply voltage and series current within the ring network change synchronously. Therefore, power balance within the ring network is achieved through the coordinated absorption or release of power by the offshore renewable energy generation unit and the underwater caisson drainage energy storage power station, under the adaptive control of the load inverter.

[0006] Because there is no fixed voltage and current within the ring network, system redundancy is reduced or eliminated, resulting in a smaller system size and increased power density. Using a single submarine power cable greatly simplifies installation, reduces material costs, and lowers construction costs. Since the current is uniform within the ring network, the load and power supply are balanced, leading to an equal load and supply voltage. Considering factors such as line loss, maximum withstand voltage of equipment, and maximum power, an optimal voltage function model is established to improve the ring network's efficiency. Furthermore, considering the uniform current and balanced load and power supply within the ring network, a voltage coefficient is established to appropriately increase the voltage within the ring network and reduce current transmission.

[0007] The working principle of this invention is as follows:

[0008] Using submarine power cables with embedded optical fibers and power conductors coaxially, or submarine power cables + 5G, n offshore new energy DC / DC converters output, n platform load DC / AC inverters input, and n caisson energy storage bidirectional DC / DC converters are connected in a ring through a single power cable to form a physically single-line ring network offshore integrated energy island power supply system.

[0009] By fully utilizing the controllable output of the voltage source of the offshore new energy DC / DC converter, and relying on the potential energy of the caisson energy storage based on the water volume and depth, the DC / DC input and output ports of the caisson energy storage bidirectional DC / DC converter are connected in series with the ring network. The ring network controller collects and analyzes all data within the ring network in real time, taking into account the length of the ring network submarine cable. For line losses, the total maximum power of new energy power generation units Total maximum platform load power Platform load DC / AC inverter power supply lower limit input voltage Maximum input and output rated power of the caisson energy storage bidirectional DC / DC converter The maximum power of the caisson energy storage bidirectional DC / DC converter The upper limit of voltage that the system can withstand In addition, factors such as the large amount of accumulated data, AI analysis, optimization, and iteration of power change rate values ​​are considered. The output voltage of the offshore renewable energy DC / DC converter, which varies with the input power of the renewable energy source, is established separately. And the absorption or release of power at the input and output terminals of the caisson energy storage bidirectional DC / DC converter. With input and output voltage .

[0010] The ring network controller or virtual power station reads data from all devices within the ring network via fiber optic communication, and combines this data with the output voltage of the offshore new energy DC / DC converter. Model, caisson energy storage bidirectional DC / DC converter input and output terminals absorb or release power With input and output voltage Functional model and Obtain the series current of the ring network under different operating conditions Due to the series current in the ring network. Equal, based on the current output power of n offshore new energy DC / DC converters within the ring network. and n platform loads DC / AC inverter DC input power The output voltage of each marine new energy DC / DC converter is adjusted separately. Each platform load DC / AC inverter adaptive input voltage It also incorporates the input and output terminals of the caisson energy storage bidirectional DC / DC converter to absorb or release power. Required input and output voltages This achieves a balance between power supply and load demand within the ring network.

[0011] Meanwhile, the stable operation of the ring network is ensured through control strategies such as ring network black start control and real-time control.

[0012] Simultaneously considering the rapid and undisturbed absorption or release of power by the caisson energy storage bidirectional DC / DC converter in the ring network, a fast response control strategy for caisson energy storage is adopted.

[0013] The ring network controller or virtual power station communicates with all devices via optical fiber, forming a physically single-line ring network communication system for the integrated marine energy island. It reads data and controls the devices according to the ring network power balance control strategy to ensure the balance between power supply and load power within the ring network.

[0014] The loads on the offshore integrated energy island platform can include, based on their processing attributes, offshore hydrogen production, offshore chemical processing, offshore oil extraction, offshore oil refining, offshore aquaculture, and underwater data centers, etc. The power supply for the loads on the offshore integrated energy island platform is provided through the output of n platform load DC / AC inverters within the ring network.

[0015] The ring network controller or virtual power station communicates with all devices via optical fiber to form a single-line ring network source-load-storage communication system. It reads data and controls the devices according to the ring network power balance control strategy to ensure the balance between power supply and load power within the ring network.

[0016] The caisson energy storage bidirectional DC / DC converter is the part of the "underwater caisson drainage energy storage power station" that connects to the ring network. Its principle is the reverse process of "pumped water storage". When there is a peak in wind power generation or surplus power, the caisson energy storage bidirectional DC / DC converter controls the DC pump in the water pump / hydro turbine generator to discharge the water in the underwater caisson to perform the energy storage process, while simultaneously drawing air into the underwater caisson. When the wind turbine generator is generating power during a low period or when there is a power outage, the caisson energy storage bidirectional DC / DC converter starts the water pump / hydro turbine generator and uses the pressure difference between the underwater caisson and the water depth to drive the hydro turbine DC generator of the water pump / hydro turbine generator to generate power and release power to the ring network, which together with the new energy power generation unit supplies power to the marine integrated energy island.

[0017] Because the caisson is cylindrical and the inner and outer water bodies are separated, when water enters the caisson for power generation and when water is discharged for energy storage, the water inside the caisson rotates in one direction along the caisson wall through the guide pipes. This generates rotational kinetic energy to drive the water-based generator to generate electricity, and also ensures the stability of the caisson structure based on the principle of gyroscopes. Since the water inside the caisson is always rotating during water intake or drainage, the water-based generator, like wind power generation or flywheel energy storage, is always in the initial state of power generation, ensuring undisturbed release into the ring network.

[0018] When fluctuations in the renewable energy generation units cause the power supply within the ring network to fall below the platform's load demand, the underwater rotary generator remains in operation. Following the ring network's rapid power support strategy, the output power of the underwater rotary generator is rapidly increased via a caisson energy storage bidirectional DC / DC converter, ensuring power balance within the ring network. Since multiple underwater caisson drainage energy storage power stations exist within the ring network, the rapid power support strategy requires at least one station to be in a low-flow drainage energy storage state (i.e., the DC pump operates at its minimum power limit). When the power supply within the ring network exceeds the load demand, the caisson energy storage bidirectional DC / DC converter can rapidly increase the power of the DC pump, absorbing excess power within the ring network without disrupting the water flow.

[0019] To achieve the above objectives, the present invention adopts the following technical solution:

[0020] The offshore integrated energy island power supply system based on a single-line ring network and an underwater caisson drainage energy storage power station includes a ring network power cable with embedded optical fiber and coaxial power cable, n offshore new energy DC / DC converters, n platform load DC / AC inverters, n caisson energy storage bidirectional DC / DC converters, and a ring network controller. The n offshore new energy DC / DC converters, n platform load DC / AC inverters, and n caisson energy storage bidirectional DC / DC converters are connected in series in a ring network according to the marine geographical distribution, forming an offshore integrated energy island power supply system based on a single-line ring network and an underwater caisson drainage energy storage power station. The ring network controller is connected to the sub-controllers embedded in the n offshore new energy DC / DC converters, n platform load DC / AC inverters, and caisson energy storage bidirectional DC / DC converters via embedded optical fiber in the ring network power cable, enabling real-time monitoring of all equipment within the ring network.

[0021] This invention also provides a control method for a marine integrated energy island power supply system based on a single-line ring network and an underwater caisson drainage energy storage power station, comprising the following steps:

[0022] Step 1. Determine the basic variable parameters of the ring network, including:

[0023] Step 1.1 Determine the total output power of the offshore new energy DC / DC converter. ;

[0024] Step 1.2 Determine the total platform load DC / AC inverter DC input power ;

[0025] Step 1.3 Determine the relevant variable parameters for the underwater caisson drainage energy storage power station;

[0026] Step 1.4 Determine the series current of the ring network Output voltage of each offshore new energy DC / DC converter and the total output voltage of the offshore new energy DC / DC converter within the ring network ;

[0027] Step 1.5 Establish the input and output voltages of the caisson energy storage bidirectional DC / DC converter. ;

[0028] Step 2. Determine the number of underwater submerged drainage energy storage power stations. And priority order of work, including:

[0029] Step 2.1 Determine the number of underwater caisson drainage energy storage power stations Remainder Power ;

[0030] Step 2.2 Determine the allocated rated power for each unit Input and output voltages of a caisson energy storage bidirectional DC / DC converter under input and output conditions Remainder Power Input and output voltages of caisson energy storage bidirectional DC / DC converter under certain conditions ;

[0031] Step 2.3 Determine the equation for the balance between ring network power supply and load power;

[0032] Step 2.4 Determine the priority order for putting underwater caisson drainage energy storage power stations into operation;

[0033] Step 3. Perform ring network black start control, including:

[0034] Step 3.1 Predict and assess the total output power of offshore renewable energy DC / DC converters within the ring network. And the total platform load DC / AC inverter predicted DC input power Determine the power ratio coefficient ;

[0035] Step 3.2 In the power ratio coefficient and At that time, the input DC voltage is distributed to the DC / AC inverter of the platform load. ;

[0036] Step 4. Real-time control of the ring network, including:

[0037] Step 4.1 Suppression of instantaneous power fluctuations during ring network power balance;

[0038] Step 4.2 When the total output power of the offshore new energy DC / DC converter... DC / AC inverter DC input power greater than the total platform load ,Right now At that time, a method for balancing power supply and load power in a ring network with a medium-term fluctuating scale was constructed.

[0039] Step 4.3 When the total output power of the offshore new energy DC / DC converter... DC / AC inverter DC input power less than the total platform load ,Right now At that time, a method for balancing ring network power supply and load power was constructed;

[0040] Step 4.4 When At that time, a method for balancing ring network power supply and load power was constructed.

[0041] Beneficial effects:

[0042] 1. Within a ring network, a power balancing strategy is employed, with no fixed voltage or current. Power balance is maintained through dynamic power regulation of batch power sources and load changes, achieved through energy storage regulation, new energy generation units, and adaptive dynamic tracking of the load. In contrast, traditional power grids use fixed voltage levels, such as 400V, 16KV, and 35KV.

[0043] 2. This invention establishes a dynamic ring network power supply voltage, ensuring that the ring network power supply voltage is optimal while establishing the ring network series current under the constraints of constraint parameters and real-time data.

[0044] 3. The platform load DC / AC inverter can adaptively control load changes and adjust the output power to meet the load's power demand;

[0045] 4. This invention establishes an underwater caisson drainage energy storage power station and a ring network energy exchange bridge through a caisson energy storage bidirectional DC / DC converter. By absorbing or releasing power, it ensures the balance between power supply and load power within the ring network and realizes surplus power caisson energy storage.

[0046] 5. Under unknown load power conditions, black start control uses deep learning to provide the current optimal voltage output to ensure power supply to the load;

[0047] 6. The underwater caisson drainage energy storage power station employs a rapid response mechanism to ensure the rapid absorption and release of power within the ring network without disturbance. On one hand, when power imbalance fluctuations occur in the ring network, based on the rapid response characteristics of the water-based rotating generator, it absorbs and releases power without disturbance. Based on this, the power can be adjusted to increase or decrease, quickly suppressing power imbalance fluctuations within the ring network. Additionally, the underwater caisson drainage energy storage power station fully utilizes the water-based rotating generator's power generation resources to drive DC water pumps for drainage, thereby increasing the energy storage capacity.

[0048] 7. This invention is based on mature control methods of offshore new energy DC / DC converters, platform load DC / AC inverters, caisson energy storage bidirectional DC / DC converters, and ring network controllers. It incorporates control methods suitable for ring networks to achieve rapid technological iteration and meet the requirements of ring network control.

[0049] 8. The ring network controller, together with the virtual power station, controls and manages the source, load, and storage within the ring network to ensure a power balance between the power supply and load within the ring network. Attached Figure Description

[0050] Figure 1 This is a structural diagram of the offshore integrated energy island power supply system based on a single-line ring network and an underwater caisson drainage energy storage power station according to the present invention.

[0051] Figure 2 A flowchart for determining the basic data of this invention;

[0052] Figure 3To determine the number and priority sequence of underwater caisson drainage energy storage power stations for this invention;

[0053] Figure 4 This is a flowchart of the ring network black start control of the present invention;

[0054] Figures 5a-5d The flowcharts are for steps 4.1 to 4.4 of the real-time control of the ring network.

[0055] The attached diagram is labeled as follows: 1. Ring network power cable; 2. Offshore new energy DC / DC converter; 3. Platform load DC / AC inverter; 4. Caisson energy storage bidirectional DC / DC converter; 5. Ring network controller; 6. Embedded optical fiber; 7. New energy power generation unit; 8. Ring network; 9. Platform load; 10. Current direction; 11. Underwater caisson drainage energy storage power station; 12. Power input / output terminal of water pump / turbine generator; 13. Power output terminal of water body rotating generator; 14. Power input / output terminal of DC / DC converter; 15. Caisson energy storage sub-controller; 16. Water storage caisson; 17. Water body rotating generator; 18. Water pump / turbine generator. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other. The invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0057] like Figure 1 As shown, the offshore integrated energy island power supply system based on a single-line ring network and an underwater caisson drainage energy storage power station of the present invention includes a ring network power cable 1 with embedded optical fiber and power cable coaxial, n offshore new energy DC / DC converters 2, n platform load DC / AC inverters 3, n caisson energy storage bidirectional DC / DC converters 4, and a ring network controller 5.

[0058] Among them, n offshore new energy DC / DC converters 2, n platform load DC / AC inverters 3, and n caisson energy storage bidirectional DC / DC converters 4 are connected in series in a ring shape through a ring power cable 1 according to the marine geographical distribution, forming an offshore integrated energy island power supply system based on a single-line ring network and an underwater caisson drainage energy storage power station; the ring network controller 5 is connected to the sub-controllers embedded in the n offshore new energy DC / DC converters 2, n platform load DC / AC inverters 3, and caisson energy storage bidirectional DC / DC converters 4 through the optical fiber 6 embedded in the ring power cable 1, and monitors all the equipment in the ring network in real time.

[0059] The aforementioned marine new energy DC / DC converter 2 includes a new energy power generation unit 7 and an embedded DC / DC sub-controller. n marine new energy DC / DC converters 2 are distributed in a series ring network 8 to supply power to the platform loads within the ring network 8.

[0060] The input of the offshore new energy DC / DC converter 2 is connected to the output of the new energy power generation unit 7. Based on the characteristics of new energy power generation, the maximum power of the new energy power generation unit 7 is obtained through the maximum power point tracking (MPPT) function. The positive and negative output terminals of the offshore new energy DC / DC converter 2 are connected to the ring network 8 through the ring network power cable 1 and according to the current direction 10 from negative to positive with the adjacent equipment.

[0061] The embedded DC / DC sub-controller monitors the offshore new energy DC / DC converter 2 in real time and maintains communication with the ring network controller 5 through the optical fiber 6. The embedded DC / DC sub-controller analyzes the data obtained from the collected data and the data obtained from the ring network controller 5, and controls the offshore new energy DC / DC converter 2 in real time according to the ring network power balance control strategy. The data is then uploaded to the ring network controller 5.

[0062] The platform load DC / AC inverter 3 includes a platform load 9 and an embedded DC / AC sub-controller; n platform load DC / AC inverters 3 are distributed in series within a ring network 8, which is the platform load within the ring network 8.

[0063] Each platform load DC / AC inverter 3 has a DC input terminal and an AC output terminal. The DC input terminal is connected to the ring network 8 through the ring network power cable 1 and is connected to the adjacent equipment in the opposite direction of the current direction 10 from negative to positive.

[0064] The AC output terminal is connected to the platform load 9. The platform load DC / AC inverter 3 converts the DC power in the ring network 8 into AC power, and supplies power to the offshore platform load 9 through the AC output terminal.

[0065] The embedded DC / AC sub-controller monitors the platform load DC / AC inverter 3 in real time and maintains communication with the ring network controller 5 through fiber optic cable 6. The embedded DC / AC sub-controller analyzes the data obtained from the collected data and the data obtained from the ring network controller 5, and controls the platform load DC / AC inverter 3 in real time according to the ring network power balance control strategy, and uploads the data to the ring network controller 5.

[0066] The aforementioned caisson energy storage bidirectional DC / DC converter 4 is a connection device between the underwater caisson drainage energy storage power station 11 and the ring network 8, enabling the underwater caisson drainage energy storage power station 11 and the ring network 8 to exchange energy. The underwater caisson drainage energy storage power station 11 is anchored to the seabed of the integrated energy island at sea and includes a water-rotating generator 17, a water pump / turbine generator integrated unit 18, a caisson energy storage sub-controller 15, a water storage caisson 16, and the caisson energy storage bidirectional DC / DC converter 4.

[0067] The caisson energy storage bidirectional DC / DC converter 4 includes a DC / DC converter power input / output terminal 14, a pump / turbine generator integrated power input / output terminal 12, and a water-rotating generator power output terminal 13. The DC / DC converter power input / output terminal 14 is connected in series with adjacent equipment within the ring network 8 via a ring network power cable 1, connecting the underwater caisson drainage energy storage power station 11 to the ring network 8, allowing energy exchange between the underwater caisson drainage energy storage power station 11 and the ring network 8. The pump / turbine generator integrated power input / output terminal 12 is connected to the pump / turbine generator integrated 18, absorbing excess power within the ring network 8 through the DC / DC converter power input / output terminal 14 and applying it to the DC pump drainage energy storage in the pump / turbine generator integrated 18. Similarly, the water turbine DC generator in the pump / turbine generator integrated 18 generates electricity using the potential energy of the water flow, releasing power into the ring network 8 through the DC / DC converter power input / output terminal 14, ensuring load and power supply balance within the ring network 8.

[0068] Because the water storage caisson 16 has a cylindrical structure, separating the inner and outer water bodies, when water is introduced into the caisson 16 for power generation and when water is discharged for energy storage, the water flow is through the guide pipes installed along the inner wall of the caisson 16. This controls the water inside the caisson 16 to rotate in one direction, generating rotational kinetic energy to drive the water-rotating generator 17 to generate electricity. Furthermore, based on the gyro principle, the structural stability of the caisson 16 is ensured. Since the kinetic energy of the water in the caisson 16 during the water intake or discharge process always keeps the water inside the caisson 16 rotating in one direction, the water-rotating generator 17, like wind power generation or flywheel energy storage, is always in a power generation state. The purpose is to quickly balance and suppress short-term fluctuations in power supply and load power within the ring network.

[0069] The power input terminal 13 of the water-rotating generator is connected to the power output terminal of the water-rotating generator 17. The power of the water-rotating generator 17 is output through the power input / output terminal 14 of the DC / DC converter. When the power generation of several new energy power generation units 7 or the platform load 9 experiences short-term fluctuations, causing a change in the power balance between the power supply and load within the ring network 8, according to the ring network rapid support power control strategy, when the ring network power is balanced, each water-rotating generator 17 outputs 1 / 2 power to supply power to the ring network. When the ring network power balance fluctuates, the ring network controller 5 controls the water-rotating generator 17 through several submerged energy storage sub-controllers 15 to increase or decrease the output power of the 1 / 2 power generator, rapidly and undisturbedly increasing or decreasing the power released into the ring network 8 to suppress fluctuations within the ring network 8 and ensure the stability of the power supply and load power balance within the ring network 8.

[0070] The caisson energy storage sub-controller 15 reads data from the water-rotating generator 17, the integrated pump / turbine generator 18, the water storage caisson 16, and the caisson energy storage bidirectional DC / DC converter 4 via a communication network, and performs real-time control according to the caisson energy storage control strategy. The caisson energy storage sub-controller 15 is connected to the ring network fiber optic 6 and exchanges data with the ring network controller 5 through the ring network fiber optic 6.

[0071] The integrated pump / hydropower generator 18 is installed at the bottom of the water storage caisson 16. The water storage caisson 16 is the carrier of energy storage capacity, and its energy storage capacity is related to the water depth, potential energy, and internal volume. The deeper the water and the larger the volume, the greater the energy storage capacity. Utilizing the linearly adjustable and wide power range of the DC pump and hydropower generator in the water-rotating generator 17 and the integrated pump / hydropower generator 18, the continuity of power absorption or release by the bidirectional DC / DC converter 4 of the caisson energy storage to the ring network 8 is ensured, reducing the balance fluctuations of the ring network 8.

[0072] Among them, the working principle of the underwater caisson drainage energy storage power station 11 is the reverse process of "pumped water storage". When the sum of the power generation of n offshore new energy DC / DC converters 2 in the ring network 8 is... The sum of the power demands of n platform load DC / AC inverters ,Right now Then, excess power is generated. At this time, the caisson energy storage sub-controller 15, based on the data provided by the ring network controller 5, uses the caisson energy storage bidirectional DC / DC converter 4 to control the DC water pump in the integrated water pump / hydro turbine generator 18 to discharge the water in the water storage caisson 16, absorb the excess power in the ring network 8 to perform the energy storage process, and at the same time draw the atmosphere into the water storage caisson 16.

[0073] This invention also provides a control method for a marine integrated energy island power supply system based on a single-line ring network and an underwater caisson drainage energy storage power station:

[0074] Step 1. Determine the basic variable parameters of the ring network.

[0075] like Figure 2 As shown, the ring network controller determines the following basic data by monitoring and collecting data from all devices within the ring network and analyzing the grid parameters at the connection point:

[0076] Step 1.1 Determine the total output power of the offshore new energy DC / DC converter. :

[0077] Since the ring network consists of n offshore renewable energy DC / DC converters, the input terminal of each offshore renewable energy DC / DC converter is connected to the output terminal of the renewable energy power generation unit to obtain renewable energy power. It features Maximum Power Point Tracking (MPPT) and can connect to new energy sources such as offshore wind power, wave power, and offshore floating photovoltaic power. Based on the ring network controller, the output power of each new energy power generation unit is collected in real time by the new energy DC / DC sub-controller. That is, the input power of each offshore new energy DC / DC converter. Considering the efficiency of offshore new energy DC / DC converters Output power of offshore new energy DC / DC converter Equal to the input power of the offshore new energy DC / DC converter Efficiency of offshore new energy DC / DC converters The product of, i.e.:

[0078] (1-1)

[0079] Based on the input power of all offshore new energy DC / DC converters within the ring network Summing these values ​​yields the total output power of the offshore new energy DC / DC converters within the ring network. ,Right now:

[0080] (1-2)

[0081] Step 1.2 Determine the total platform load DC / AC inverter DC input power :

[0082] The platform load DC / AC inverter converts the DC power within the ring network into AC power to supply the AC loads. Since the ring network consists of n platform load DC / AC inverters, each platform load DC / AC inverter has a DC input power of... With load power Demand has changed; the input power of the n total platform load DC / AC inverters within the ring network has changed. Changes occur simultaneously.

[0083] The platform load power collected by the ring network controller through the platform load DC / AC sub-controller is the AC output power of the platform load DC / AC inverter. Considering the platform load DC / AC inverter efficiency At that time, the platform load DC / AC inverter output AC power Equal to the DC input power of the platform load DC / AC inverter Platform load DC / AC inverter efficiency The product of, i.e.:

[0084] (1-3)

[0085] AC power output from n platform load DC / AC inverters Summing these values ​​yields the total DC input power of the DC / AC inverters within the ring network's platform load. for:

[0086] (1-4)

[0087] Step 1.3 Determine the relevant variable parameters for the underwater caisson drainage energy storage power station:

[0088] Step 1.3.1 Determine the input and output power of each caisson energy storage bidirectional DC / DC converter. :

[0089] Since the input and output power of each underwater caisson drainage energy storage power station includes: the power of the integrated water pump / hydro turbine generator. With the output power of the water-rotating generator The sum of the input power from the input and output terminals of a caisson energy storage bidirectional DC / DC converter ,Right now:

[0090] (1-5)

[0091] Step 1.3.2 Determine the input and output power of several caisson energy storage bidirectional DC / DC converters. :

[0092] According to equations (1-1) and (1-4), when the power supply and load power of the ring network are unbalanced, the total output power of the offshore new energy DC / DC converter in the ring network is... With the total platform load DC / AC inverter DC input power The difference is achieved by adjusting the input and output power of several caisson energy storage bidirectional DC / DC converters. To absorb or release power in the ring network:

[0093] when To ensure a balance between power supply and load within the ring network, the DC water pump in the caisson energy storage system was activated, consuming power. Power is absorbed into the ring network through the input and output terminals of several caisson energy storage bidirectional DC / DC converters. ,Right now:

[0094] (1-6)

[0095] Based on equation (1-5), the input and output power of several caisson energy storage bidirectional DC / DC converters is obtained, and the power absorbed by the ring network is obtained. :

[0096] (1-7)

[0097] when At that time, in order to ensure the balance between power supply and load power within the ring network, the DC generator of the caisson energy storage turbine is started to generate power output. Power is released to the ring network through the input and output terminals of several caisson energy storage bidirectional DC / DC converters. ,Right now:

[0098] (1-8)

[0099] Based on equation (1-5), the power released from the input and output terminals of several caisson energy storage bidirectional DC / DC converters to the ring network is obtained. :

[0100] (1-9)

[0101] in, For several units or seats, Integers; . Input power to several caisson energy storage bidirectional DC / DC converters; Output power for several caisson energy storage bidirectional DC / DC converters; It provides power output for several caisson energy storage water-based rotating generators.

[0102] Step 1.3.3 Determine the total output power of the water-based rotary generator. :

[0103] Make full use of the water-rotating generator power generation resources of the underwater caisson drainage energy storage power stations within the ring network, and increase the output power of the n water-rotating generators in the n underwater caisson drainage energy storage power stations. Summing these values ​​yields the total output power of the water-based rotating generator. ,Right now:

[0104] (1-10)

[0105] Step 1.3.4 Determine the power suppression power for the balance between ring network power supply and load power:

[0106] Step 1.3.4.1 Perform rapid suppression of power imbalance fluctuations within the short-term fluctuating ring network:

[0107] With the total output power of marine new energy DC / DC converters And the total platform load DC / AC inverter DC input power Changes in demand cause fluctuations in the power supply and load balance within the ring network;

[0108] To quickly suppress power imbalance fluctuations caused by changes in ring network power supply and load power, the power supply power is balanced with the load power by including the output power of each water-based rotating generator in the power supply power. ,Right now:

[0109] (1-11)

[0110] Based on equation (1-5), the input and output power of each caisson energy storage bidirectional DC / DC converter is controlled by the caisson energy storage sub-controller. Utilizing the rapid response characteristics of water-based rotating generators, such as flywheel energy storage and wind power generation, when power imbalances and fluctuations occur, the output power of the water-based rotating generator can be adjusted. Based on this, increase or decrease the power, that is:

[0111] (1-12)

[0112] The output power adjustment range of the water-based rotating generator is as follows: It can quickly suppress power imbalance fluctuations within the instantaneous ring network. .

[0113] Because each water-rotating generator outputs power All components participate in power supply, thus ensuring a consistent output power from the total water-based rotating generators during power balance within the ring network. When sudden power imbalance fluctuations occur in the ring network, the water-based rotating generator, with its characteristics of power generation similar to flywheel energy storage and the fast power response speed of wind power generation, participates in the output power of the total water-based rotating generator. Based on this, the total output power of the water-based rotating generator is controlled. Increase or decrease power to suppress fluctuations in power imbalance.

[0114] In addition, it fully utilizes the output power of the underwater caisson drainage energy storage power station's water-rotating generator. This drives a DC water pump to drain water and increase the energy storage capacity.

[0115] The total output power of the water-based rotating generator is Subtract the output power of the water-spinning generators of several underwater submerged drainage energy storage power stations. This is equivalent to the sum of the power generated by the remaining water-based rotating generators in the underwater caisson drainage energy storage power station, even without the integrated water pump / hydropower generator in operation. ,Right now:

[0116] (1-13)

[0117] Step 1.3.4.2 Suppress power imbalance within the ring network at a medium-term fluctuation scale:

[0118] Taking full advantage of the large capacity of each underwater caisson drainage energy storage power station, when the power supply and load power are balanced within the ring network, power is absorbed or released through the input and output of the pumps / hydro turbine generators of several underwater caisson drainage energy storage power stations, according to equation (1-12). The output power of the water-rotating generator, which belongs to several underwater submerged drainage energy storage power stations, is similar to that of the other two. cooperation, Input and output power through several caisson energy storage bidirectional DC / DC converters Right now:

[0119] (1-14)

[0120] And according to formula (1-6) or formula (1-8), in the underwater caisson drainage energy storage power station corresponding to the absence of a water pump / hydropower generator in operation, the sum of the output power of all remaining water-body rotating generators. Thus, the power balance equation within the ring network at the medium-term fluctuation scale is obtained:

[0121] when At that time, we obtained:

[0122] (1-15)

[0123] Therefore, it can be seen from equation (1-15) that when The operating power absorbed by the pumps / hydro-turbine generators of several underwater caisson drainage energy storage power stations is as follows: Stop the water body rotation generator output power The sum of the power outputs is generated by rotating the generator in the remaining water body. With the cooperation of several caisson energy storage bidirectional DC / DC converters, the input power is... The remaining y caisson energy storage bidirectional DC / DC converters release power at their input and output terminals. ,Right now:

[0124] (1-16)

[0125] To smooth out fluctuations in the power supply and load balance within the ring network.

[0126] when hour,

[0127] (1-17)

[0128] Therefore, it can be seen from equation (1-17) that when At that time, the power output of the underwater caisson drainage energy storage power station corresponding to the integrated pump / turbine generator of the underwater caisson drainage energy storage power station was released. Total output power of water-based rotating generator With coordinated regulation, the input and output power is controlled by several caisson energy storage bidirectional DC / DC converters. And the remaining power released from the input and output terminals of the bidirectional DC / DC converter for energy storage in the caisson This helps to smooth out fluctuations in the power supply and load balance within the ring network.

[0129] in, For the remaining underwater caisson drainage energy storage power stations that do not have integrated pump / hydro turbine generators in operation, the input and output power of all caisson energy storage bidirectional DC / DC converters; For the remaining underwater caisson drainage energy storage power stations where no integrated pump / hydropower generator is in operation, the output power of the bidirectional DC / DC converter at the input and output terminals of the caisson energy storage is released at this time. scope Input / output power release of the integrated water pump / hydro turbine generator Greater than the output power of the water-rotating generator ,Right now: Due to the total output power of the water-based rotating generator Subtract the output power of the water-spinning generators of several underwater submerged drainage energy storage power stations. This equals the output power of the water-rotating generator when the integrated water pump / hydropower generator is not operating at its rated power. ,Right now:

[0130] (1-18)

[0131] Step 1.4 Determine the series current of the ring network Output voltage of each offshore new energy DC / DC converter and the total output voltage of the offshore new energy DC / DC converter within the ring network :

[0132] Because the offshore integrated energy island power supply system adopts a single-line ring network and underwater caisson drainage energy storage power station, the changes in new energy power generation units and loads within the ring network directly affect the balance of power supply and load within the ring network. Therefore, in this offshore integrated energy island power supply system based on a single-line ring network and underwater caisson drainage energy storage power station, the output voltage of the offshore new energy DC / DC converter adopts a dynamic voltage output operating mode that varies with the power supply, while the input voltage of the platform load DC / AC inverter adopts an adaptive output voltage mode that adapts to the platform load power. The adjustable voltage operating mode, and the absorption and release of power at the input and output terminals of the caisson energy storage bidirectional DC / DC converter. This coordination ensures a balance between power supply and load within the ring network. It also considers constraints within the ring network, such as the impact of submarine cable length on line losses and the maximum power output of the total offshore renewable energy generation units. Total maximum platform load power This directly affects the maximum line loss. The lower limit input voltage of the DC / AC inverter power supply for the platform load is also considered. Maximum withstand voltage of offshore new energy power generation system Maximum input and output rated power of the caisson energy storage bidirectional DC / DC converter The upper limit of voltage that the system can withstand Factors such as these also play a role. Within the upper limit of the allowable voltage of the ring network, the higher the line voltage within the ring network, the lower the line loss.

[0133] in, Output power for marine new energy DC / DC converters; For the total input power of marine renewable energy; The total platform load is the DC / AC inverter's DC input power. Input and output power for each caisson energy storage bidirectional DC / DC converter; .

[0134] The length of the ring network and the total maximum power of new energy sources Total load maximum power The lower limit input voltage of the DC / AC inverter power supply for each platform load. Maximum withstand voltage of new energy power generation system The upper limit of the voltage that the system can withstand. The data design is known.

[0135] First, the ring network controller reads the input power of all offshore new energy DC / DC converters. The MAX function is used to find the maximum input power of the offshore renewable energy DC / DC converter within the ring network. ,Right now:

[0136] (1-19)

[0137] And based on the maximum input power of the offshore new energy DC / DC converter The corresponding output voltage of the offshore new energy DC / DC converter Maximum voltage withstand capability for offshore new energy power generation units With safety system The product of these values ​​is less than the upper limit of the voltage the system can withstand. Right now:

[0138] (1-20)

[0139] Step 1.4.1 Determine the series current of the ring network :

[0140] Based on the maximum input power of offshore new energy DC / DC converters With conversion efficiency The product of these two factors, and then the output voltage of the corresponding offshore new energy DC / DC converter. The ratio yields the series current of the ring network. :

[0141] (1-21)

[0142] in, The safety factor ranges from 80% to 99%. ; This is the maximum voltage that the offshore new energy power generation unit can withstand. Maximum input power for offshore new energy DC / DC converters The corresponding output voltage of the marine new energy DC / DC converter;

[0143] Step 1.4.2 Determine the output voltage of each offshore new energy DC / DC converter. :

[0144] The ring network controller monitors the input power of each offshore renewable energy DC / DC converter in real time. With conversion efficiency The product of these is then combined with the series current of the ring network. The ratio yields the output voltage of each offshore new energy DC / DC converter. ,Right now:

[0145] (1-22)

[0146] Based on equation (1-22), we obtain:

[0147] (1-23)

[0148] Step 1.4.3 Determine the total output voltage of the offshore new energy DC / DC converter within the ring network. :

[0149] The output voltage of each offshore new energy DC / DC converter is given by equation (1-23). Summing yields the total output voltage of the offshore new energy DC / DC converter. ,Right now:

[0150] (1-24)

[0151] Among them, the maximum voltage withstand capability of n offshore new energy power generation systems The sum is less than the upper limit of the voltage that the system can withstand. ,Right now ;

[0152] Step 1.5 Establish the input and output voltages of the caisson energy storage bidirectional DC / DC converter. :

[0153] The total output power of the offshore new energy DC / DC converter is determined in real time by the ring network controller according to equation (1-2). Each caisson energy storage bidirectional DC / DC converter absorbs or releases power at its input and output. Equation (1-4) represents the total platform load DC / AC inverter DC input power. And the constraint parameters within the ring network, calculated and analyzed:

[0154] Step 1.5.1 When Based on equation (1-6), we obtain:

[0155] (1-25)

[0156] At this time, the input voltage of several caisson energy storage bidirectional DC / DC converters is... Equivalent to the input and output power absorbed by several caisson energy storage bidirectional DC / DC converters Based on equation (1-21), the series current of the ring network The ratio is thus obtained:

[0157] (1-26)

[0158] Step 1.5.2 When Based on equation (1-8), we obtain:

[0159] (1-27)

[0160] Therefore, the output voltage of several caisson energy storage bidirectional DC / DC converters is... Equivalent to the input-output power release of several caisson energy storage bidirectional DC / DC converters Based on equation (1-21), the series current of the ring network The ratio is thus obtained:

[0161] (1-28)

[0162] Step 1.5.3 When When the total output power of the offshore new energy DC / DC converter within the ring network The output is zero, that is: To ensure a balance between the ring network power supply and the load power, the ring network power supply capacity is set to... These are respectively equal to the total platform load DC / AC inverter input DC power The sum equals the input-output power released by several caisson energy storage bidirectional DC / DC converters. ,Right now Therefore, the output voltage of several caisson energy storage bidirectional DC / DC converters is... Equal to the maximum withstand voltage of n offshore renewable energy power generation units according to equation (1-20) With safety system The product of these two values ​​is less than the upper limit of the voltage that the system can withstand. ,Right now:

[0163] (1-29)

[0164] Based on equations (1-28) and (1-29), the power supply through the ring network is calculated. Output voltage of several caisson energy storage bidirectional DC / DC converters The ratio yields the series current of the ring network. :

[0165] (1-30)

[0166] in, Each caisson energy storage bidirectional DC / DC converter absorbs or releases power to the ring network at its input and output terminals.

[0167] 1) When the input power at the input and output terminals of the caisson energy storage bidirectional DC / DC converter is... When absorbing power into the ring network, the input power at the input and output terminals of the caisson energy storage bidirectional DC / DC converter is... DC power generation for water body rotation Power requirements of DC water pumps The sum is: .

[0168] Among them, when the DC water pump requires power Greater than the power output of DC power generation by water rotation At that time, that is: Input power at the input and output terminals of the caisson energy storage bidirectional DC / DC converter and input voltage Absorb power into the ring network. Conversely, release power into the ring network. .

[0169] 2) When the output power of the input and output terminals of the caisson energy storage bidirectional DC / DC converter is... In the process of releasing power to the ring network At that time, the caisson energy storage bidirectional DC / DC converter outputs power through the hydro turbine DC power generation. The output power of the bidirectional DC / DC converter with caisson energy storage is obtained from the input and output terminals. At this time, the output power of each caisson energy storage bidirectional DC / DC converter at the input and output terminals is... It generates electricity by rotating water generators. Integrated water pump / hydro turbine generator set with DC power generation capacity The sum of these values ​​releases power into the ring network; as data accumulates, iterative updates using self-learning AI technology provide a better function model, ensuring the input and output voltage of each caisson energy storage bidirectional DC / DC converter is optimized. At its optimal value;

[0170] in, ; The input and output voltages of the pumps / hydropower generators in each underwater caisson drainage energy storage power station; the input and output power absorbed or released by the pumps / hydropower generators in each underwater caisson drainage energy storage power station and the corresponding input and output voltages of the bidirectional DC / DC converters in the caisson energy storage system. The relationship is directly proportional, meaning that the input and output power absorbed or released by the pumps / hydropower generators of each underwater submerged drainage energy storage power station is proportional to the power generated. The increase corresponds to the bidirectional input and output voltage of the caisson energy storage bidirectional DC / DC converter. Increased synchronously.

[0171] Step 2. Determine the number of underwater submerged drainage energy storage power stations. and priority order of work, such as Figure 3 As shown.

[0172] Step 2.1 Determine the number of underwater caisson drainage energy storage power stations Remainder Power :

[0173] Because the power balance of the ring network is based on equation (1-12). In step 1.3.4.1, power imbalance fluctuations within the short-term fluctuation scale ring network are rapidly suppressed, and all underwater submerged drainage energy storage power stations have water-based rotating generators that output power. Consider the underwater caisson drainage energy storage power station's integrated pump / turbine generator absorbing or releasing power into the ring network. At that time, the DC power generation of the DC water pump or turbine is at its rated power. The optimal operating condition is achieved during operation, maximizing the utilization of DC power generated by the DC pump or turbine at its rated power. Under these conditions, it is put into operation, thereby inputting and outputting power through several caisson energy storage bidirectional DC / DC converters. Divide by the rated power of the DC water pump or turbine DC generator With the output power of the water-rotating generator The sum of the power, the quotient obtained The number and surplus power of the pump / turbine generator integrated units in the underwater caisson drainage energy storage power station under rated input and output power conditions. ,Right now:

[0174] (2-1)

[0175] After transformation using equation (2-1), we obtain:

[0176] (2-2)

[0177] Among them, the rated power of DC water pumps or DC power generation of each underwater caisson drainage energy storage power station within the ring network is... They are all equal; The number of pumps / hydro turbine generators put into operation in underwater caisson drainage energy storage power stations under rated input and output power conditions; The rated input and output power of the bidirectional DC / DC converter for caisson energy storage is equal to the rated power of the DC pump or DC generator of the underwater caisson drainage energy storage power station. The output power of the water-rotating generator in the same underwater caisson drainage energy storage power station sum; The remainder power.

[0178] Step 2.2 Determine the allocated rated power for each unit Input and output voltages of a caisson energy storage bidirectional DC / DC converter under input and output conditions Remainder Power Input and output voltages of caisson energy storage bidirectional DC / DC converter under certain conditions .

[0179] Based on equations (1-26), (1-28), and (2-2), we obtain Due to the series current in the ring network They are equal, therefore we have the following equation:

[0180] (2-3)

[0181] Therefore, the rated power of the input and output of each caisson energy storage bidirectional DC / DC converter is related to... Input and output power of several caisson energy storage bidirectional DC / DC converters The ratio is compared with the input and output voltages of several caisson energy storage bidirectional DC / DC converters. The product of and is used to allocate the rated power of each unit. Input and output voltages of a caisson energy storage bidirectional DC / DC converter under input and output conditions ,Right now:

[0182] (2-4)

[0183] Same remainder power Input and output power of several caisson energy storage bidirectional DC / DC converters The ratio is compared with the input and output voltages of several caisson energy storage bidirectional DC / DC converters. The product of and gives the remainder power. Input and output voltages of caisson energy storage bidirectional DC / DC converter under certain conditions ,Right now:

[0184] (2-5)

[0185] Step 2.3 Determine the equation for the balance between ring network power supply and load power:

[0186] According to formula (2-1) Then the remainder power Through A submerged caisson drainage energy storage power station with DC power generation capacity of DC water pumps or turbines The output power of the water-rotating generator in the same underwater caisson drainage energy storage power station The sum of the remainders and power The power output is regulated and is less than the rated power of the DC power generation of the DC water pump or turbine. With the output power of the water-rotating generator The sum is:

[0187] (2-6)

[0188] Therefore, based on the formula get:

[0189] (2-7)

[0190] Based on equations (2-7), (2-2), and (2-6), we obtain:

[0191] (2-8)

[0192] (2-9)

[0193] Among them, based on equation (1-12), we obtain .

[0194] Therefore, based on equations (2-8) and (2-9), it can be seen that... The underwater caisson drainage energy storage power station inputs and outputs rated power via a corresponding caisson energy storage bidirectional DC / DC converter. With regulation The input-output residual power of the caisson energy storage bidirectional DC / DC converter in the underwater caisson drainage energy storage power station. ,as well as The underwater caisson drainage energy storage power station outputs power from the water-rotating generator via the corresponding caisson energy storage bidirectional DC / DC converter input and output terminals. Summation power The sum equals the total platform load DC / AC inverter DC input power within the ring network. Total output power of marine new energy DC / DC converters within the ring network The difference is used to achieve a balance between the ring network power supply and the load power.

[0195] Therefore, based on equation (2-9), the power released to the ring network by the underwater caisson drainage energy storage power station is related to the total output power of the offshore new energy DC / DC converter. Combining these, we obtain the equation for ring network power supply and load power balance:

[0196] (2-10)

[0197] Step 2.3.1 When the ring network power supply and load power are balanced At that time, due to The underwater caisson drainage energy storage power station inputs and outputs power through the corresponding caisson energy storage bidirectional DC / DC converter. Relatively constant, based on equations (2-6) and (2-9) through regulation The input-output residual power of the bidirectional DC / DC converter for underwater caisson drainage energy storage power station. and The underwater caisson drainage energy storage power station outputs power from the water-rotating generator via the corresponding caisson energy storage bidirectional DC / DC converter input and output terminals. Summation power This coordination helps to achieve a balance between ring network power supply and load power.

[0198] in, Input-output remainder power The corresponding underwater caisson drainage energy storage power station; The number of remaining underwater caisson drainage energy storage power stations corresponding to those without integrated pump / hydro turbine generator units in operation;

[0199] Step 2.3.2 When At that time, through regulation The underwater submerged drainage energy storage power station and the corresponding water-body rotating generator output power sum equal and through Taiwan-type caisson energy storage bidirectional DC / DC converter input and output power . The formula Substituting into equation (2-2), we get: ;

[0200] (2-11)

[0201] Based on equation (2-11), the input and output power of several caisson energy storage bidirectional DC / DC converters can be seen. It is by Submersible caisson drainage energy storage power station pump / hydro turbine generator integrated unit rated input and output power The power output of all underwater submerged drainage energy storage power stations is via water-rotating generators. The sum of these factors balances the power supply and load power within the ring network.

[0202] in, Input and output power of several caisson energy storage bidirectional DC / DC converters; This represents the total output power of the water-based rotating generator. For underwater caisson drainage energy storage power stations without integrated pumps / hydropower generators in operation, the sum of the power generated by the corresponding water-rotating generators is considered; that is:

[0203] (2-12)

[0204] If n underwater submerged drainage energy storage power stations are connected within the ring network, what is the total number of power stations? Therefore, the total number of underwater caisson drainage energy storage power stations within the ring network is... Subtract the number of underwater submerged drainage energy storage power stations under rated input and output conditions for integrated pump / hydro turbine generator units. Then, the power is calculated by adding the input and output remainders. Corresponding underwater caisson drainage energy storage power station The difference is equal to the number of remaining underwater caisson drainage energy storage power stations corresponding to the pumps / hydro turbine generators that did not participate in the operation of the power input / output pumps. ,Right now: .

[0205] The number of underwater submerged caisson drainage energy storage power stations for integrated pump / hydro turbine generators under rated input and output conditions. It is an integer; ; The total number of underwater submerged drainage energy storage power stations within the ring network. It is an integer; The number of remaining underwater caisson drainage energy storage power stations corresponding to those that did not participate in the operation of the rated power input / output water pump / hydro turbine generator integrated unit. It is an integer;

[0206] Since the water-body rotating generator of each underwater caisson drainage energy storage power station within the ring network is in power generation mode, even if the DC pump or turbine DC generator input and output power is... It equals zero, that is: The water-based rotating generator is still generating electricity, and the output power of the water-based rotating generator is controlled through the caisson energy storage sub-controller. By adjusting the magnitude and utilizing the fast power response speed, it can participate in the suppression of disturbance-free power imbalance fluctuations within the ring network.

[0207] Therefore, the input and output power of all caisson energy storage bidirectional DC / DC converters are... This corresponds to the presence of several water-based rotating generators participating in power generation and output. The aim is to regulate the output power of the water-based rotating generator. The increase or decrease, that is, in The range adjustment quickly suppresses short-term power imbalance fluctuations within the ring network. The output power of each water-rotating generator... All are less than the rated power of DC power generation for DC water pumps or turbines. ,Right now .

[0208] in, Input and output power of several caisson energy storage bidirectional DC / DC converters; This represents the total output power of the water-based rotating generator. The number of pumps / hydro turbine generators put into operation in underwater caisson drainage energy storage power stations under rated input and output power conditions; Input and output power for several caisson energy storage bidirectional DC / DC converters; For several underwater caisson drainage energy storage power stations, the DC water pump load power or the DC power generation power of the turbines is used; For each underwater caisson drainage energy storage power station, specify the DC water pump load power or the DC power generation power of the turbine. The rated input and output power of the bidirectional DC / DC converter for caisson energy storage is equal to the rated power of the DC pump or DC generator of the underwater caisson drainage energy storage power station. The output power of the water-rotating generator in the same underwater caisson drainage energy storage power station sum; The output power of the water-rotating generator in several underwater caisson drainage energy storage power stations; For several underwater caisson drainage energy storage power stations, the DC water pumps or turbines that generate DC power do not participate in the input and output power of the ring network. The output power of the water-rotating generator in the underwater caisson drainage energy storage power station is... Calculate the sum of power.

[0209] Step 2.4 Determine the priority order for putting underwater caisson drainage energy storage power stations into operation:

[0210] Simultaneously, the absorption or release of power by the bidirectional DC / DC converter in the caisson energy storage system should also be considered. During the process, the water storage capacity within the underwater caisson drainage energy storage power station changes constantly, meaning that each underwater caisson drainage energy storage power station stores its remaining power generation capacity. They are all different, designed to efficiently utilize the remaining power generation capacity stored in each underwater caisson drainage energy storage power station. Therefore, utilize The sorting function stores the remaining power generation capacity of n underwater submerged drainage energy storage power stations according to demand. Sort.

[0211] Step 2.4.1 The remaining power generation capacity of the underwater submerged drainage energy storage power station during the process of absorbing power from the ring network by the water pump is sorted from smallest to largest as follows:

[0212] Therefore, the ring network controller controls the input and output power of several caisson energy storage bidirectional DC / DC converters. Absorbing power from the ring network In this case, priority is given to underwater caisson drainage energy storage power stations with large water storage capacity. The remaining power generation capacity is then stored by utilizing water pumps to drain water and absorb power from the ring network. Small, based on this The sorting function stores the remaining power generation capacity of n underwater submerged drainage energy storage power stations. Sorting, that is:

[0213] Sequential functions from smallest to largest:

[0214] (2-13)

[0215] This results in an ascending order of sorting:

[0216] (2-14)

[0217] in, To store the remaining power generation capacity of the first underwater caisson drainage energy storage power station To store the remaining power generation capacity of the second underwater caisson drainage energy storage power station. To store the remaining power generation capacity for the nth underwater submerged drainage energy storage power station. , Integers;

[0218] The ring network controllers are selected sequentially from the fewest to the most numerous in the ring network: The underwater submerged drainage energy storage power station with the smallest remaining power generation capacity is ranked as follows. It is the second smallest underwater submerged drainage energy storage power station in terms of remaining power generation capacity. To store the largest remaining power generation capacity of the underwater caisson drainage energy storage power station, the input and output power of several caisson energy storage bidirectional DC / DC converters are... Absorbing power from the ring network At that time, according to formula (2-8) The number of underwater submerged drainage energy storage power stations is based on the remaining power generation capacity stored. Select the corresponding underwater caisson drainage energy storage power station from smallest to largest, and then select the corresponding caisson energy storage bidirectional DC / DC converter input and output terminals rated power. With regulation The input-output residual power of the caisson energy storage bidirectional DC / DC converter in the underwater caisson drainage energy storage power station. ,as well as The underwater caisson drainage energy storage power station outputs power from the water-rotating generator via the corresponding caisson energy storage bidirectional DC / DC converter input and output terminals. Summation power In coordination, it absorbs power from the ring network to achieve a balance between the power supply of the ring network and the load power.

[0219] Step 2.4.2: When the turbine releases power, the remaining power generation capacity of the underwater caisson drainage energy storage power station is sorted from largest to smallest:

[0220] Similarly, the ring network controller controls the input and output power of several caisson energy storage bidirectional DC / DC converters. Release power generation to the ring network In this case, priority should be given to underwater caisson drainage energy storage power stations with small water storage capacity, as the power generated by the sequential release of power through turbines using the potential energy of the water depth is relatively large, thus storing the remaining power generation capacity. Larger, based on this The sorting function stores the remaining power generation capacity of the n underwater sump drainage energy storage power station. That is to Sort from largest to smallest, thus obtaining:

[0221] (2-15)

[0222] The ring network controllers are selected from the largest to the smallest values ​​in the ring network: The underwater submerged drainage energy storage power station with the largest remaining power generation capacity is ranked as follows. It is the second largest underwater submerged drainage energy storage power station in terms of storing remaining power generation capacity. This is a submerged caisson drainage energy storage power station with the smallest remaining power generation capacity. The input and output power of several caisson energy storage bidirectional DC / DC converters are... Release power to the ring network At that time, according to formula (2-8) Number of underwater submerged drainage energy storage power stations and their remaining power generation capacity Select the corresponding underwater caisson drainage energy storage power stations from largest to smallest, and then select the corresponding caisson energy storage bidirectional DC / DC converters with rated output power at the input and output terminals. With regulation The input-output residual power of the caisson energy storage bidirectional DC / DC converter in the underwater caisson drainage energy storage power station. ,as well as The underwater caisson drainage energy storage power station outputs power from the water-rotating generator via the corresponding caisson energy storage bidirectional DC / DC converter input and output terminals. Summation power The sum equals the total platform load DC / AC inverter DC input power within the ring network. Total output power of marine new energy DC / DC converters within the ring network The difference is used to achieve a balance between the ring network power supply and the load power.

[0223] Step 3. Perform ring network black start control:

[0224] like Figure 4 As shown, to ensure the normal operation of the ring network during black start, the power supply within the ring network must be greater than the load power. This requires the following steps:

[0225] Step 3.1 Predict and assess the total output power of offshore renewable energy DC / DC converters within the ring network. And the total platform load DC / AC inverter predicted DC input power Determine the power ratio coefficient .

[0226] Based on historical data on renewable energy generation units and load demand within the ring network, as well as real-time power prediction and analysis data of renewable energy generation units, the ring network controller predicts and analyzes the output power of each offshore renewable energy DC / DC converter within the ring network. and the predicted DC input power of each platform load DC / AC inverter .

[0227] Based on the collected input power of each marine new energy DC / DC converter Based on equations (1-1) and (1-2), the total output power of the offshore new energy DC / DC converter within the ring network is obtained. .

[0228] Meanwhile, the ring network controller predicts the AC output power of the DC / AC inverter based on the historical load of the platform within the ring network during the same period. Demand data is used to convert the platform load DC / AC inverter efficiency according to equation (1-3). At that time, the platform load DC / AC inverter predicted DC input power Equal to the platform load DC / AC inverter output AC power The reciprocal of the efficiency of the DC / AC inverter with respect to the platform load The product of, i.e.:

[0229] (3-1)

[0230] Based on equation (1-4), the predicted output AC power of n platform load DC / AC inverters is calculated. Summing these values ​​yields the total platform load within the ring network and the predicted DC input power of the DC / AC inverter. Demand. Among them... .

[0231] Based on data analysis and equation (1-2), the total output power of the offshore new energy DC / DC converter within the ring network is given. The predicted DC input power of the DC / AC inverter and the total platform load within the ring network. The ratio of demand to power ratio coefficient is obtained. ,Right now:

[0232] (3-2)

[0233] Among them, through the power ratio coefficient It can reflect the power of new energy power generation units and load demand within the ring network. Furthermore, when the power of new energy power generation units exceeds the load power, it can be used to calculate the power ratio coefficient. And according to equation (1-24), the total output voltage of the marine new energy DC / DC converter It can distribute the input DC voltage to each platform load DC / AC inverter. .

[0234] Step 3.2 In the power ratio coefficient and At that time, the input DC voltage is distributed to the DC / AC inverter of the platform load. :

[0235] To ensure the load power demand during black start-up of the ring network, the ring network controller uses equation (3-2) to control the total power generation of new energy sources. Predicted DC input power of DC / AC inverters within the ring network's total platform load Size comparison analysis:

[0236] Step 3.2.1 When the power ratio coefficient This indicates the total power generation capacity of new energy sources within the ring network. The predicted DC input power of the DC / AC inverter is greater than or equal to the total platform load within the ring network. ,Right now: .

[0237] Based on step 1.4, the series current of the ring network is obtained according to equation (1-21). Equation (1-22) Output voltage of each offshore new energy DC / DC converter The total output voltage of the offshore new energy DC / DC converter within the sum of equations (1-24) ring network ;

[0238] Due to the series current in the ring network Same, therefore To ensure that each platform load DC / AC inverter is allocated DC input power To maximize the power output of all caisson energy storage bidirectional DC / DC converters at both input and output terminals. It is zero, that is It is in a short-circuit state, at which time the total output voltage of the offshore new energy DC / DC converter is... The ring network power supply voltage during black start-up And the input DC voltage is distributed with the total platform load DC / AC inverter. Equal, that is Therefore, each load DC / AC sub-controller is based on the series current of the ring network. Predicted DC input power of each platform load DC / AC inverter Power ratio coefficient Calculate the corresponding distributed input DC voltage for the DC / AC inverter of this platform load. ,Right now:

[0239] (3-3)

[0240] Therefore, based on equation (3-3), the input DC voltage is obtained by allocating DC / AC inverters to each platform load. ,Right now:

[0241] (3-4)

[0242] At this time, the load DC / AC sub-controller receives the platform load DC / AC inverter distribution input DC voltage issued by the corresponding ring network controller. Data is used to control the corresponding input DC voltage allocated to the DC / AC inverters of this platform's load. Current in series with ring network The product of these two values ​​yields the DC input power allocated to the platform load DC / AC inverter. .

[0243] At this point, the DC input power is allocated to the DC / AC inverter of each platform load. All achieved a predicted AC output power of the DC / AC inverter greater than or equal to the corresponding platform load. It is also the load forecast power. ,Right now:

[0244] (3-5)

[0245] This ensures the total output power of the marine new energy DC / DC converter within the ring network. The predicted DC input power of the DC / AC inverter is greater than the total platform load within the ring network. ,Right now At the same time, it satisfies the predicted AC output power of each load DC / AC inverter at the black start moment. need.

[0246] Step 3.2.2 When the power ratio coefficient This indicates that the total output power of the offshore new energy DC / DC converter within the ring network can be obtained based on equation (1-2). The predicted DC input power of the DC / AC inverter is less than the total platform load within the ring network. ,Right now Determine the total power supply of the ring network. Total output voltage of marine new energy DC / DC converter Ring network power supply voltage at black start Distribute the input DC voltage to each platform load DC / AC inverter. Due to the series current in the ring network Same, therefore .

[0247] Step 3.2.2.1 Considering the black start of the ring network, the predicted AC input power of the DC / AC inverter should meet the total platform load within the ring network. The requirement is to ensure that each platform load DC / AC inverter is allocated DC input power. The DC input power of the DC / AC inverter exceeds the predicted DC input power of each platform load. ,Right now: At this time, the input and output power of several caisson energy storage bidirectional DC / DC converters are... Release power to the ring network According to formula (2-9) Number of underwater submerged drainage energy storage power stations and their remaining power generation capacity Select the corresponding underwater caisson drainage energy storage power stations from largest to smallest, corresponding in order to the rated output power of the input and output terminals of the caisson energy storage bidirectional DC / DC converter. Harmony and Regulation The input-output residual power of the caisson energy storage bidirectional DC / DC converter in the underwater caisson drainage energy storage power station. Because, according to equations (2-1) and (2-2), the remainder power... Less than the rated input and output power of the caisson energy storage bidirectional DC / DC converter ,Right now: To ensure that the output power of the ring network is greater than the power consumption of the load during black start, the residual power is set according to equation (2-9). and The underwater caisson drainage energy storage power station outputs power from the water-rotating generator via the corresponding caisson energy storage bidirectional DC / DC converter input and output terminals. Summation power Equal to the rated input and output power of the caisson energy storage bidirectional DC / DC converter ,Right now: Thus we obtain Number of underwater caisson drainage energy storage power stations; caisson energy storage; bidirectional DC / DC converter; input / output rated power. Equal to the total platform load DC / AC inverter predicted DC input power With the total output power of the marine new energy DC / DC converter The difference is:

[0248] (3-6)

[0249] Therefore, the ring network power supply at the black start time can be obtained according to equation (3-6). equal The underwater caisson drainage energy storage power station has corresponding caisson energy storage bidirectional DC / DC converters with rated output power at the input and output terminals. With the total output power of the marine new energy DC / DC converter The sum of these values ​​represents the total platform load, and the predicted DC input power of the DC / AC inverter is also included. Power supply, i.e.:

[0250] (3-7)

[0251] in, This represents the total power supply of the ring network. The underwater caisson drainage energy storage power station outputs power from the water-rotating generator via the corresponding caisson energy storage bidirectional DC / DC converter input and output terminals. Summation power Much smaller than the rated input and output power of the caisson energy storage bidirectional DC / DC converter. . This represents the total output power of the water-based rotating generator. The DC power generation capacity of the turbine in the integrated pump / turbine generator of several underwater caisson drainage energy storage power stations; Output power at the input and output terminals of several caisson energy storage bidirectional DC / DC converters; The rated power output of the bidirectional DC / DC converter for caisson energy storage includes the rated DC power generation of the turbine in the integrated pump / turbine generator of the underwater caisson drainage energy storage power station. Output power of water-based rotating generator ; for The input and output residual power of the bidirectional DC / DC converter for the submerged caisson drainage energy storage power station is based on equation (2-6) and includes: .

[0252] Step 3.2.2.2 Based on this, the output voltage of each marine new energy DC / DC converter is obtained according to equation (1-22). Equation (1-Right 24) yields the total output voltage of the marine new energy DC / DC converter within the current ring network. .

[0253] Step 3.2.2.3 Determine the total power supply voltage of the ring network. :

[0254] Based on equation (3-7) and step 2, determine the underwater caisson drainage energy storage power station. Quantity and priority of work order, obtained Series current with ring network Equal to, and equation (1-24) yields the total output voltage of the current marine new energy DC / DC converter within the ring network. Summing these values ​​yields the total supply voltage of the ring network under black-start conditions. ,Right now:

[0255] (3-8)

[0256] Ring network power supply voltage at black start This is equivalent to the DC / AC inverter distributing the input voltage to provide the total platform load within the ring network. Thus, the ring network supply voltage at the black start moment is obtained. The DC / AC inverter's predicted DC input voltage exceeds the load of each platform. Sum of voltages ,Right now:

[0257] (3-9)

[0258] Step 3.2.2.4 Based on equation (3-7), calculate the total power supply of the ring network. The series current of the ring network at the black start moment is obtained from equation (3-9) and the principle of electrical work. Right now:

[0259] (3-10)

[0260] Therefore, the relevant parameters of equation (3-10) can satisfy the conditions for the black start time.

[0261] Step 3.2.2.5 Calculate the input DC voltage allocated to each platform load DC / AC inverter. :

[0262] Predicted output AC power of each platform load DC / AC inverter based on predictive analysis Combined with equation (2-16), the predicted DC input power of each platform load DC / AC inverter within the ring network is obtained. .

[0263] And predict the DC input power of the DC / AC inverters of the n platform loads in the predictive analysis. Summation, i.e.: (3-11)

[0264] The predicted DC input power of the DC / AC inverter within the ring network at the moment before black start is obtained from the predictive analysis. need.

[0265] Based on equation (3-9) and the predictive analysis of the DC / AC inverter of each platform load in the ring network, the DC input power is predicted. The predicted DC input power of the DC / AC inverter and the total platform load within the ring network. The ratio, and then compared with the ring network power supply voltage at the moment of black start. The product of these factors is used to allocate the DC input voltage to each platform load DC / AC inverter. ,Right now:

[0266] (3-12)

[0267] Therefore, we can conclude that:

[0268] (3-13)

[0269] The ring network series current obtained according to equation (36) Since the loads are equal within the ring network, the DC / AC inverters of each platform are allocated the corresponding input DC voltage. Current in series with ring network The product equals the DC input power allocated by the DC / AC inverter to the platform load. Simultaneously, according to equation (3-9), the DC input power is distributed to the DC / AC inverter of this platform load. Platform load DC / AC inverter efficiency The product of these values ​​is greater than the predicted AC output power of the DC / AC inverter for the corresponding platform load. ,Right now This ensures the predictive assessment of AC load power during black start. The demand.

[0270] Step 4. Real-time control of the ring network:

[0271] Due to the volatility of renewable energy power generation units and the uncertainty of load demand, the renewable energy power supply and load power within the ring network face real-time challenges. Based on equations (1-2) and (1-4), the total output power of the offshore renewable energy DC / DC converter within the ring network is obtained. The DC input power of the DC / AC inverter is greater than, equal to, or less than the total platform load within the ring network. There are three states. These include power imbalance between supply and load at the instantaneous and short-term fluctuation scales within the ring network, and power imbalance between supply and load at the medium-term fluctuation scale.

[0272] Step 4.1 Suppression of instantaneous power fluctuations during ring network power balance, such as Figure 5a As shown.

[0273] Step 4.1.1 Determine the equation for the balance between ring network power supply and load power:

[0274] To quickly respond to power imbalance fluctuations caused by changes in ring network power supply and load power, and given the relatively small capacity of the water-based rotating generator and its rapid response to power changes, the sub-controller of the caisson energy storage unit controls the input and output terminals of each caisson energy storage bidirectional DC / DC converter to absorb or release power when the ring network power supply and load power are balanced. This includes the output power of the water-rotating generator. Power is output by rotating the generator in the water. Based on this, the power imbalance fluctuations within the ring network can be quickly suppressed by increasing or decreasing the power supply or load power. Therefore, when the power supply and load power are balanced within the ring network, the equation for the power supply and load power balance of the ring network can be obtained according to equations (2-11), (2-2), (1-12), and (2-6):

[0275] (4-1)

[0276] in, Input and output power of several caisson energy storage bidirectional DC / DC converters; This represents the total output power of the water-based rotating generator. The number of pump / turbine generator units put into operation in an underwater caisson drainage energy storage power station under rated input and output power conditions. Integers; DC power generation for several underwater caisson drainage energy storage power stations; The rated input and output power of the DC water pump or DC power generator of each underwater caisson drainage energy storage power station; The output power of the water-rotating generator in several underwater caisson drainage energy storage power stations; In addition to the DC power generation of several underwater caisson drainage energy storage power stations' DC water pumps or turbines, The output power of the underwater submerged drainage energy storage power station's water-rotating generator Calculate the sum of power.

[0277] Let n underwater submerged drainage energy storage power stations be connected within the ring network, and the total number of power stations be... Therefore, the total number of underwater caisson drainage energy storage power stations within the ring network is... Subtract the number of underwater submerged drainage energy storage power stations under the rated input and output power conditions of the integrated pump / hydro turbine generator. ,as well as A single underwater caisson drainage energy storage power station is equivalent to the remaining number of underwater caisson drainage energy storage power stations corresponding to pumps / hydro turbines that do not participate in the operation of power input / output. ,Right now: .

[0278] in, The total number of underwater submerged drainage energy storage power stations within the ring network. It is an integer; The remaining number of underwater caisson drainage energy storage power stations corresponding to those that are not involved in the operation of the rated power input / output water pump / hydro turbine generator integrated unit. It is an integer; The purpose of the underwater caisson drainage energy storage power station is to regulate the input, output, and residual power of the bidirectional DC / DC converter for caisson energy storage. , It is an integer.

[0279] Equation (4-1) shows that when the ring network power supply and load power are balanced:

[0280] Step 4.1.2 When the total output power of the offshore new energy DC / DC converter within the ring network... Equal to the total platform load DC / AC inverter DC input power within the ring network ,Right now At this time, based on equations (2-2) and (2-6), Substituting this into equation (4-1) for ring network power supply and load power balance, we get:

[0281] ;

[0282] get ;

[0283] make At that time, we obtained:

[0284] (4-2)

[0285] At this time, the caisson energy storage sub-controller controls... The input power of the DC water pump in the submerged caisson drainage energy storage power station's integrated pump / hydro turbine generator unit. Negative, absorbs the same The output power of the underwater submerged drainage energy storage power station's water-rotating generator At the same time, absorb the remaining quantity Summation power Again with The output power of the underwater submerged drainage energy storage power station's water-rotating generator sum.

[0286] Consider the remaining quantity Summation power and The output power of the underwater submerged drainage energy storage power station's water-rotating generator The sum of these values ​​is greater than the rated input and output power of the integrated pump / hydropower generator of the submerged caisson drainage energy storage power station. ,Right now: At that time, appropriately reduce the remaining quantity. Water-based rotating generator output power Sum of power Therefore, we can conclude that: This shows that The input power of the DC water pump in the submerged caisson drainage energy storage power station's integrated pump / hydro turbine generator unit. absorb The output power of the underwater submerged drainage energy storage power station's water-rotating generator At the same time, it also absorbs the remaining quantity Water-based rotating generator output power Summation power ,Right now: In other words, through the ring network... The input power of the DC water pump in the submerged caisson drainage energy storage power station's integrated pump / hydro turbine generator unit. Power supply does work, absorbs power To ensure the balance between the ring network power supply and the load power, and at the same time to discharge The underwater submerged drainage energy storage power station increases reservoir capacity and energy storage capacity.

[0287] Due to power and The sum equals ,Right now:

[0288] (4-3)

[0289] When the power supply and load power of the ring network are balanced, it can be concluded that:

[0290] On the one hand, when sudden power imbalance fluctuations occur in the ring network, based on the fast power generation response speed of the water-based rotating generator, the output power of the water-based rotating generator... By increasing or decreasing the regulation power based on the existing power, power imbalance fluctuations within the ring network can be quickly suppressed.

[0291] On the other hand, the underwater caisson drainage energy storage power station makes full use of the water body rotating generator power generation resources to drive DC water pumps to drain water and increase the energy storage capacity.

[0292] Step 4.1.3 When short-term fluctuations occur in the power supply and load power within the ring network, resulting in an imbalance, the total output power of the offshore new energy DC / DC converter... DC / AC inverter DC input power greater than or less than the total platform load ,Right now or At that time, based on equation (4-1) and equation (4-3), the following equations are obtained:

[0293] (4-4)

[0294] According to equation (4-4), the caisson energy storage sub-controller is used for control. Number of underwater submerged drainage energy storage power stations and The sorting function sorts the input and output rated power of the corresponding integrated water pump / hydro turbine generator in sequence. and in sequence Submerged caisson drainage energy storage power station pump / hydro turbine generator integrated power input and output power The sum of these, and then combined with the total output power of the water-based rotating generator. The sum of these values, along with the corresponding bidirectional DC / DC converter for caisson energy storage, enables the input and output power. Absorbing or releasing power into the ring network For the total platform load DC / AC inverter DC input power With the total output power of the marine new energy DC / DC converter Power difference support.

[0295] Therefore, when the power supply and load power of the ring network are in balance, sudden changes in the power supply and load power cause power imbalance fluctuations. Based on the relatively small capacity and rapid response of the water-based rotating generator to power changes, the ring network controller controls the output power of the total water-based rotating generator. Based on this, by controlling the sub-controllers of the submerged energy storage units in all underwater submerged drainage energy storage power stations, the output power of the water-spinning generators can be increased or decreased. Input and output power via caisson energy storage bidirectional DC / DC converter It absorbs or releases power in the ring network, quickly suppressing fluctuations in the power imbalance of the ring network.

[0296] Step 4.2 When the total output power of the offshore new energy DC / DC converter... DC / AC inverter DC input power greater than the total platform load Right now At that time, the method for balancing the power supply and load power of a ring network under medium-term fluctuation scale is as follows: Figure 5b As shown.

[0297] Step 4.2.1 Determine the series current of the ring network Output voltage of each offshore new energy DC / DC converter and the total output voltage of the offshore new energy DC / DC converter within the ring network :

[0298] The ring network controller collects data from all devices within the ring network in real time, and bases this data on the input power of each new energy DC / DC converter within the ring network. Step 1.4 yields the series current of the ring network as shown in equation (1-21). Equation (1-22) Output voltage of each offshore new energy DC / DC converter The total output voltage of the offshore new energy DC / DC converter within the sum of equations (1-24) ring network .

[0299] Step 4.2.2 Adaptively adjust the input voltage of the DC / AC inverter to the platform load. :

[0300] Since the ring network consists of n platform load DC / AC inverters, the DC input power of each platform load DC / AC inverter is... and output power As load demand changes, the total platform load DC / AC inverter input power within the ring network... Changes occur simultaneously.

[0301] in, This refers to the DC input power of the platform load DC / AC inverter. The output AC power of the platform load DC / AC inverter is also the load power; The efficiency of the DC / AC inverter for the platform load.

[0302] Therefore, at a certain moment, based on equation (1-4), the total DC input power of the platform load DC / AC inverter can be used to obtain the DC input power of the n platform load DC / AC inverters within the ring network. The sum of these values ​​represents the total platform load DC / AC inverter DC input power. .

[0303] Due to changes in load demand, the DC input power of the platform load DC / AC inverter With output power The load DC / AC sub-controller adjusts accordingly. At this point, the platform load DC / AC inverter efficiency is not considered. Under loss conditions, the DC input power of the platform load DC / AC inverter at the previous moment will be... With output power Perform difference calculations to obtain the required adjustment value for the DC / AC inverter's DC input power at the platform load. Right now:

[0304] (4-5)

[0305] Based on equation (4-5), the differential platform load DC / AC inverter DC input power Compared to the platform load DC / AC inverter DC input power at the previous moment The sum of these values ​​yields the DC input power of the platform load DC / AC inverter that needs to be adjusted at the current moment. Right now:

[0306] (4-6)

[0307] in, The DC input power of the DC / AC inverter on the differential platform load can be positive or negative. The DC input power of the platform load DC / AC inverter that needs to be adjusted at the current moment; The DC input power of the DC / AC inverter is the platform load at the previous moment. The AC power output of the DC / AC inverter for the platform load at the previous moment is also the AC power consumption of the AC load at the previous moment. The current AC power output of the DC / AC inverter for the platform load is also the current AC load power consumption.

[0308] And the ring network series current obtained according to equations (44) and (1-21) Adaptive adjustment of platform load DC / AC inverter input voltage ,Right now:

[0309] (4-7)

[0310] Therefore, the load DC / AC sub-controller adaptively adjusts the input voltage of the platform load DC / AC inverter. Control platform load DC / AC inverter DC input power To meet the current AC load power requirements need.

[0311] Similarly, based on equation (4-7), the input DC voltage of the DC / AC inverter for the n platform loads in the ring network is... The sum of these values ​​represents the total platform load DC / AC inverter input DC voltage. ,Right now:

[0312] (4-8)

[0313] Step 4.2.3 Determine the input and output terminals of the n caisson energy storage bidirectional DC / DC converters. , Voltage and output voltage :

[0314] The ring network consists of n underwater submerged drainage energy storage power stations. At that time, based on the ring network power supply and load power balance equation (4-1), the underwater caisson drainage energy storage power station is determined according to step 2. The quantity and priority of operation are determined by the input and output power of several caisson energy storage bidirectional DC / DC converters. The total output voltage of the offshore new energy DC / DC converter is obtained through step 4.2.1 by absorbing power from the ring network. Current series current of the ring network The rated input and output power of each unit is obtained by allocating it according to equations (2-4) and (2-5). Input and output voltages of caisson energy storage bidirectional DC / DC converter under certain conditions And obtain the remainder power Input and output voltages of caisson energy storage bidirectional DC / DC converter under certain conditions Equation (4-7) adaptively adjusts the input voltage of the DC / AC inverter on the platform load. The input DC voltage of the DC / AC inverter for the total platform load is obtained according to equation (4-8). And according to equation (1-12), when the input and output power of the caisson energy storage bidirectional DC / DC converter... Absorbing power from the ring network At that time, the DC water pump input power in the integrated water pump / hydro turbine generator is... The power absorbed by the ring network is thus obtained as follows:

[0315] (4-9)

[0316] Based on equation (2-8), we get: ;

[0317] Since the power absorbed into the ring network is negative according to (4-9), we can conclude that:

[0318] (4-10)

[0319] Due to the series current in the ring network They are equal, therefore we have:

[0320] (4-11)

[0321] From equations (4-10) and (4-11), it can be seen that in When the ring network power supply is balanced with the load power, the ring network controller controls each of the sub-controllers of the caisson energy storage.

[0322] Among them, the remaining quantity The corresponding underwater submerged drainage energy storage power station's water-spinning generator power generation capacity Divide by the series current of the ring network Get the remaining quantity Corresponding output voltage of the input and output terminals of the caisson energy storage bidirectional DC / DC converter ,Right now: Therefore, the remaining quantity Corresponding output voltage of the input and output terminals of the caisson energy storage bidirectional DC / DC converter Summing yields the remaining number of underwater submerged drainage energy storage power stations corresponding to those that did not participate in the operation of the rated power input / output water pumps / hydro turbine generator units. voltage .

[0323] Step 4.2.3.1 Based on formula (2-14), at the rated input power of the DC water pump... Under these conditions, the remaining power generation capacity is stored sequentially from smallest to largest. Select accordingly This underwater submerged drainage energy storage power station utilizes the DC water pump input power of the corresponding integrated water pump / hydro turbine generator. Power output of water-based rotating generator The sum equals ,through The input power voltage of the caisson energy storage bidirectional DC / DC converter is at the input and output terminals. Absorb rated power into the ring network ;

[0324] Step 4.2.3.2 By sorting The next A submerged caisson drainage energy storage power station that regulates the input power of the DC water pump in the integrated pump / turbine generator unit. With the voltage of the water-rotating generator The sum of them is Because the DC water pump in the integrated water pump / hydro turbine generator absorbs power from the ring network. It is negative, therefore it should be At that time, Submerged caisson drainage energy storage power station caisson energy storage bidirectional DC / DC converter input / output terminal input voltage Absorbing surplus power into the ring network ;

[0325] when Time Submerged caisson drainage energy storage power station caisson energy storage bidirectional DC / DC converter input and output voltage Release surplus power to the ring network .

[0326] in, To absorb the remaining power into the ring network; The input voltage at the input and output terminals of the caisson energy storage bidirectional DC / DC converter when absorbing residual power into the ring network; To release the remaining power into the ring network;

[0327] The output voltage at the input and output terminals of the caisson energy storage bidirectional DC / DC converter when releasing the remaining power to the ring network; Step 4.2.3.3 If n underwater caisson drainage energy storage power stations are connected to the ring network, the total number of power stations is... Therefore, the total number of underwater caisson drainage energy storage power stations within the ring network is... Subtract the number of underwater submerged drainage energy storage power stations under rated input and output conditions for integrated pump / hydro turbine generator units. Then, the power is calculated by adding the input and output remainders. Corresponding underwater caisson drainage energy storage power station The difference is equal to the remaining number of underwater submerged drainage energy storage power stations corresponding to the integrated water pumps / hydro turbine generators that did not participate in the operation of power input / output. ,Right now: .

[0328] The number of underwater submerged caisson drainage energy storage power stations for integrated pump / hydro turbine generators under rated input and output conditions. Integers; ; The total number of underwater submerged drainage energy storage power stations within the ring network. Integers; The remaining number of underwater caisson drainage energy storage power stations corresponding to those that are not involved in the operation of the rated power input / output water pump / hydro turbine generator integrated unit. Integers;

[0329] Therefore, by controlling the remaining quantity The corresponding underwater submerged drainage energy storage power station's water-spinning generator power generation capacity The output voltage is generated by the input and output terminals of the caisson energy storage bidirectional DC / DC converter. .

[0330] Among them, voltage The remaining number of underwater caisson drainage energy storage power stations divided by the number of those corresponding to pumps / hydro turbines that are not involved in the operation of the rated power input / output pumps / hydro turbine generators. To obtain the remaining quantity The output voltage of the input and output terminals of the bidirectional DC / DC converter for each underwater caisson drainage energy storage power station. ,Right now:

[0331] (4-12)

[0332] Therefore The underwater caisson drainage energy storage power station outputs voltage through the input and output terminals of the caisson energy storage bidirectional DC / DC converter. Power release for ring network This enables rapid suppression of power balance fluctuations between the ring network power supply and the load.

[0333] in, For DC water pumps at rated input power The input voltage at the input and output terminals of the caisson energy storage bidirectional DC / DC converter under the specified conditions; The number of underwater submerged caisson drainage energy storage power stations for integrated pump / hydro turbine generators under rated input and output conditions. Integers; The power output from the input / output terminals of the caisson energy storage bidirectional DC / DC converter for the corresponding underwater caisson drainage energy storage power station that does not participate in the operation of the pump / hydro turbine generator integrated unit; The total number of underwater submerged drainage energy storage power stations within the ring network. Integers; The remaining number of underwater submerged drainage energy storage power stations corresponding to water pumps / hydro turbine generators that are not operating at their rated input / output power. Integers;

[0334] Step 4.3 When the total output power of the offshore new energy DC / DC converter... DC / AC inverter DC input power less than the total platform load , At that time, the method of balancing power supply and load power in a ring network, such as Figure 5c As shown.

[0335] Step 4.3.1 Determine the ring network power supply voltage Ring network series current Output voltage of offshore new energy DC / DC converter and the DC input voltage of each platform load DC / AC inverter :

[0336] The ring network controller collects data from all devices within the ring network in real time, and bases this data on the input power of each new energy DC / DC converter within the ring network. Through step 1.4, the series current of the ring network is obtained according to equation (1-21). Equation (1-22) Output voltage of each offshore new energy DC / DC converter The total output voltage of the offshore new energy DC / DC converter within the sum of equations (1-24) ring network Step 4.3.1.1 Determine the ring network power supply voltage Rated power of each unit Input and output voltages of caisson energy storage bidirectional DC / DC converter under output conditions Sum of power Input and output voltages of caisson energy storage bidirectional DC / DC converter under certain conditions :

[0337] Based on equations (1-27) and (1-28), the input and output power of the bidirectional DC / DC converter for caisson energy storage are obtained respectively. Output voltage of caisson energy storage bidirectional DC / DC converter .

[0338] Based on equation (1-27), the power balance within the ring network and the series current of the ring network are considered. Equal determination of ring network power supply voltage for:

[0339] (4-13)

[0340] The rated power of each unit is allocated based on equation (2-3). Input and output voltages of a caisson energy storage bidirectional DC / DC converter under input and output conditions Remainder Power Input and output voltages of caisson energy storage bidirectional DC / DC converter under certain conditions The equation yields:

[0341] (4-14)

[0342] The rated power of each unit is then allocated according to formula (2-4). Output voltage of caisson energy storage bidirectional DC / DC converter under output conditions ,Right now:

[0343] (4-15)

[0344] Similarly, the remainder power is obtained according to equation (2-5). Input and output voltages of caisson energy storage bidirectional DC / DC converter under certain conditions ,Right now:

[0345] (4-16)

[0346] Therefore, based on equation (2-10), the series current of the ring network... Equal to step 4.3.1.1, determine the ring network power supply voltage. The ring network power supply voltage is obtained. equal The input and output voltage of the caisson energy storage bidirectional DC / DC converter and The input and output voltage of the caisson energy storage bidirectional DC / DC converter The total output voltage of the marine new energy DC / DC converter within the ring network Then with the remaining quantity The input and output voltage of the caisson energy storage bidirectional DC / DC converter The sum of these values ​​is equal to the total platform load DC / AC inverter DC input voltage. , because:

[0347] (4-17)

[0348] Among them, the remaining quantity The corresponding underwater submerged drainage energy storage power station's water-spinning generator power generation capacity Divide by the series current of the ring network Get the remaining quantity Corresponding output voltage of the input and output terminals of the caisson energy storage bidirectional DC / DC converter ,Right now: Therefore, the remaining quantity Corresponding output voltage of the input and output terminals of the caisson energy storage bidirectional DC / DC converter Summing yields the remaining number of underwater submerged drainage energy storage power stations corresponding to those that did not participate in the operation of the rated power input / output water pumps / hydro turbine generator units. voltage .

[0349] Step 4.3.1.2 Determine the DC input voltage of the DC / AC inverter for each platform load. :

[0350] Based on (1-21) ring network series current Equal to the DC input power of all platform loads in the current ring network DC / AC inverter This is how the DC input voltage of the DC / AC inverter for each platform load is allocated. ,Right now: Therefore, based on the series current of the ring network The DC input voltage of the DC / AC inverter for each platform load is obtained through allocation. To ensure the current total output power of marine new energy DC / DC converters DC / AC inverter DC input power less than the total platform load , The ring network power supply and load power balance under the conditions.

[0351] Therefore, the underwater caisson drainage energy storage power station is determined by the ring network controller through equation (4-17) and all the caisson energy storage sub-controllers according to step 2. The quantity and priority of work order, as shown in equation (2-15) at the rated output power of the hydro-turbine DC generator. Under the given conditions, the corresponding controls are as follows:

[0352] Step 4.3.2.1 Store the remaining power generation capacity in descending order of size. Select accordingly This underwater submerged drainage energy storage power station utilizes the rated output power of the turbine-DC generator in the corresponding integrated pump / turbine generator unit. and the power generation capacity of the corresponding water-based rotating generator. sum ,through The input and output voltage of the caisson energy storage bidirectional DC / DC converter Release power to the ring network ;

[0353] Step 4.3.2.2 By sorting The next A submerged caisson drainage energy storage power station that regulates the DC turbine power output of the integrated pump / hydropower generator. and the power generation of the water-rotating generator And sum to ,through Submerged caisson drainage energy storage power station caisson energy storage bidirectional DC / DC converter input and output voltage Release surplus power to the ring network ;

[0354] Step 4.3.2.3 By controlling the remaining quantity The corresponding underwater submerged drainage energy storage power station's water-spinning generator power generation capacity The output voltage is generated by the input and output terminals of the caisson energy storage bidirectional DC / DC converter. Power release for ring network This enables rapid suppression of power balance fluctuations between the ring network power supply and the load. Among these, For the hydro-turbine DC generator at rated input power Input voltage at the input and output terminals of the caisson energy storage bidirectional DC / DC converter under the specified conditions; The number of underwater submerged caisson drainage energy storage power stations for integrated pump / hydro turbine generators under rated input and output conditions. It is an integer; The power output from the input / output terminals of the caisson energy storage bidirectional DC / DC converter for the underwater caisson drainage energy storage power station corresponding to the integrated pump / hydro turbine generator that does not participate in the operation of the rated power input / output pump; The total number of underwater submerged drainage energy storage power stations within the ring network. It is an integer; The remaining number of underwater submerged drainage energy storage power stations corresponding to water pumps / hydro turbine generators that are not operating at their rated input / output power. It is an integer;

[0355] Step 4.4 When Methods for balancing power supply and load power in time-loop networks, such as Figure 5d As shown.

[0356] When the total output power of the offshore new energy DC / DC converter At that time, according to the equation (2-10) for the balance between ring network power supply and load power, we get:

[0357] (4-18)

[0358] Step 4.4.1 Determine the ring network power supply :

[0359] According to step 1.5.3, the ring network power supply capacity is set. These are respectively equal to the total platform load DC / AC inverter input DC power The sum is obtained based on equation (4-18):

[0360] (4-19)

[0361] Step 4.4.2 Determine the ring network power supply voltage :

[0362] The output voltage of several caisson energy storage bidirectional DC / DC converters is obtained according to equation (1-29). Equation (1-30) is used to obtain the series current of the ring network. The rated power of each unit is obtained by allocating it according to equation (2-4). Input and output voltages of a caisson energy storage bidirectional DC / DC converter under input and output conditions The remainder power is obtained from equation (2-5). Input and output voltages of caisson energy storage bidirectional DC / DC converter under certain conditions Based on equation (4-19) and the series current in the ring network. They are equal, thus the ring network power supply voltage is obtained. equal The input and output voltage of the caisson energy storage bidirectional DC / DC converter and Output voltage of the caisson energy storage bidirectional DC / DC converter Then with the remaining quantity The input and output voltage of the caisson energy storage bidirectional DC / DC converter The sum of these values ​​is equal to the total platform load DC / AC inverter DC input voltage. ,Right now:

[0363] (4-20)

[0364] in, for The underwater caisson drainage energy storage power station outputs a water-based rotating generator via the corresponding caisson energy storage bidirectional DC / DC converter input and output terminals, summing the power output. The corresponding output voltage; for Submerged caisson drainage energy storage power station caisson energy storage bidirectional DC / DC converter input and output rated power The product, the corresponding output voltage. The rated output power of the submerged caisson drainage energy storage power station's integrated pump / turbine generator is... With the output power of the water-rotating generator The sum of the corresponding output voltages; for The residual power output of the bidirectional DC / DC converter for the submerged caisson drainage energy storage power station. The corresponding output voltage;

[0365] Step 4.4.3 Store the remaining power generation capacity in descending order of size. Select accordingly This underwater submerged drainage energy storage power station utilizes the rated output power of the turbine-DC generator in the corresponding integrated pump / turbine generator unit. and the power generation capacity of the corresponding water-based rotating generator. sum ,through The input and output voltage of the caisson energy storage bidirectional DC / DC converter Release power to the ring network ;

[0366] Step 4.4.3.1 By sorting The next A submerged caisson drainage energy storage power station that regulates the DC turbine power output of the integrated pump / hydropower generator. and the power generation of the water-rotating generator And sum to ,through Submerged caisson drainage energy storage power station caisson energy storage bidirectional DC / DC converter input and output voltage Release surplus power to the ring network ;

[0367] Step 4.4.3.2 By controlling the remaining quantity The corresponding underwater submerged drainage energy storage power station's water-spinning generator power generation capacity The output voltage is generated by the input and output terminals of the caisson energy storage bidirectional DC / DC converter. Among them, voltage The remaining number of underwater caisson drainage energy storage power stations divided by the number of those corresponding to pumps / hydro turbines that are not involved in the operation of the rated power input / output pumps / hydro turbine generators. To obtain the remaining quantity The output voltage of the input and output terminals of the bidirectional DC / DC converter for each underwater caisson drainage energy storage power station. ,Right now:

[0368] (4-21)

[0369] Therefore, through the remaining quantity The underwater caisson drainage energy storage power station outputs voltage via the input and output terminals of the caisson energy storage bidirectional DC / DC converter. Power release for ring network This enables rapid suppression of power balance fluctuations between the ring network power supply and the load.

[0370] Step 4.4.3.3 Determine the DC input voltage of the DC / AC inverter for each platform load. :

[0371] The ring network series current obtained according to equation (1-30) And the DC input power of all platform loads DC / AC inverters within the currently collected ring network. This is how the DC input voltage of the DC / AC inverter for each platform load is allocated. ,Right now: Series current in a ring network The DC input voltage of the DC / AC inverter for each platform load is obtained through allocation. To ensure the current total output power of marine new energy DC / DC converters When it equals zero, according to equations (2-2) and (4-18), we get:

[0372] (4-22)

[0373] As can be seen from equation (4-22), the output power of several underwater caisson drainage energy storage power stations is obtained through the corresponding caisson energy storage bidirectional DC / DC converter input and output power terminals. sum With remaining quantity Submerged caisson drainage energy storage power station caisson energy storage bidirectional DC / DC converter input and output power The total platform load DC / AC inverter DC input power powered by.

Claims

1. A marine integrated energy island power supply system based on a single-line ring network and an underwater caisson drainage energy storage power station, characterized in that, It includes a ring network power cable with embedded optical fiber and power cable coaxial, n offshore new energy DC / DC converters, n platform load DC / AC inverters, n caisson energy storage bidirectional DC / DC converters and a ring network controller; the n offshore new energy DC / DC converters, n platform load DC / AC inverters and n caisson energy storage bidirectional DC / DC converters are connected in series in a ring according to the marine geographical distribution, forming an offshore integrated energy island power supply system based on a single-line ring network and underwater caisson drainage energy storage power station; The ring network controller connects to the sub-controllers embedded in n offshore new energy DC / DC converters, n platform load DC / AC inverters, and caisson energy storage bidirectional DC / DC converters via fiber optic cables embedded in the ring network power cables, and monitors all equipment in the ring network in real time.

2. The offshore integrated energy island power supply system based on a single-line ring network and an underwater caisson drainage energy storage power station as described in claim 1, characterized in that, The aforementioned offshore new energy DC / DC converter includes a new energy power generation unit and an embedded DC / DC sub-controller; n offshore new energy DC / DC converters are distributed in series within a ring network to power the platform loads within the ring network; the input of the offshore new energy DC / DC converter is connected to the output of the new energy power generation unit, and the positive and negative output terminals of the offshore new energy DC / DC converter are connected to the ring network via ring network power cables, following the current direction from negative to positive, and connected to adjacent devices before and after it; the embedded DC / DC sub-controller monitors the offshore new energy DC / DC converter in real time and maintains communication with the ring network controller via optical fiber; the embedded DC / DC sub-controller analyzes the collected data and the data obtained from the ring network controller, and controls the offshore new energy DC / DC converter in real time according to the ring network power balance control strategy, and uploads the data to the ring network controller; the aforementioned platform load DC / AC inverter includes the platform load and an embedded DC / AC sub-controller; n platform load DC / AC inverters are distributed in series within a ring network to power the platform loads within the ring network.

3. The offshore integrated energy island power supply system based on a single-line ring network and an underwater caisson drainage energy storage power station as described in claim 1, characterized in that, The embedded DC / AC sub-controller monitors the platform load DC / AC inverters in real time and maintains communication with the ring network controller via optical fiber. Based on the collected data and data analysis from the ring network controller, the embedded DC / AC sub-controller controls the platform load DC / AC inverters in real time according to the ring network power balance control strategy, and uploads the data to the ring network controller. The caisson energy storage bidirectional DC / DC converter is the connection device between the underwater caisson drainage energy storage power station and the ring network, enabling energy exchange between them. The underwater caisson drainage energy storage power station is anchored on the seabed of the integrated energy island and includes a water-rotating generator, a pump / turbine generator, a caisson energy storage sub-controller, a water storage caisson, and the caisson energy storage bidirectional DC / DC converter. The aforementioned caisson energy storage bidirectional DC / DC converter includes a DC / DC converter power input / output terminal, a pump / turbine generator integrated power input / output terminal, and a water-rotating generator power output terminal. The DC / DC converter power input / output terminal is connected in series with adjacent equipment within the ring network via a ring network power cable, connecting the underwater caisson drainage energy storage power station to the ring network and facilitating energy exchange between the underwater caisson drainage energy storage power station and the ring network. The pump / turbine generator integrated power input / output terminal is connected to the pump / turbine generator integrated power unit, absorbing excess power within the ring network through the DC / DC converter power input / output terminal and applying it to the DC pump drainage energy storage in the pump / turbine generator integrated power unit. Similarly, the water turbine DC generator in the pump / turbine generator integrated power unit generates electricity using the potential energy of the water flow, releasing power into the ring network through the DC / DC converter power input / output terminal, ensuring load and power supply balance within the ring network.

4. A control method for a marine integrated energy island power supply system based on a single-line ring network and an underwater caisson drainage energy storage power station, characterized in that, Includes the following steps: Step 1. Determine the basic variable parameters of the ring network, including: Step 1.1 Determine the total output power of the offshore new energy DC / DC converter. ; Step 1.2 Determine the total platform load DC / AC inverter DC input power ; Step 1.3 Determine the relevant variable parameters for the underwater caisson drainage energy storage power station; Step 1.4 Determine the series current of the ring network Output voltage of each offshore new energy DC / DC converter and the total output voltage of the offshore new energy DC / DC converter within the ring network ; Step 1.5 Establish the input and output voltages of the caisson energy storage bidirectional DC / DC converter. ; Step 2. Determine the number of underwater submerged drainage energy storage power stations. And priority order of work, including: Step 2.1 Determine the number of underwater caisson drainage energy storage power stations Remainder Power ; Step 2.2 Determine the allocated rated power for each unit Input and output voltages of a caisson energy storage bidirectional DC / DC converter under input and output conditions Remainder Power Input and output voltages of caisson energy storage bidirectional DC / DC converter under certain conditions ; Step 2.3 Determine the equation for the balance between ring network power supply and load power; Step 2.4 Determine the priority order for putting underwater caisson drainage energy storage power stations into operation; Step 3. Perform ring network black start control, including: Step 3.1 Predict and assess the total output power of offshore renewable energy DC / DC converters within the ring network. And the total platform load DC / AC inverter predicted DC input power Determine the power ratio coefficient ; Step 3.2 In the power ratio coefficient and At that time, the input DC voltage is distributed to the DC / AC inverter of the platform load. ; Step 4. Real-time control of the ring network, including: Step 4.1 Suppression of instantaneous power fluctuations during ring network power balance; Step 4.2 When the total output power of the offshore new energy DC / DC converter... DC / AC inverter DC input power greater than the total platform load ,Right now At that time, a method for balancing power supply and load power in a ring network with a medium-term fluctuating scale was constructed. Step 4.3 When the total output power of the offshore new energy DC / DC converter... DC / AC inverter DC input power less than the total platform load ,Right now At that time, a method for balancing ring network power supply and load power was constructed; Step 4.4 When At that time, a method for balancing ring network power supply and load power was constructed.

5. The control method according to claim 4, characterized in that, Step 1.1 includes: Based on the ring network controller, the output power of each new energy power generation unit is collected in real time through the new energy DC / DC sub-controller. That is, the input power of each offshore new energy DC / DC converter. Considering the efficiency of offshore new energy DC / DC converters Output power of offshore new energy DC / DC converter Equal to the input power of the offshore new energy DC / DC converter Efficiency of offshore new energy DC / DC converters The product of, i.e.: （1-1） Based on the input power of all offshore new energy DC / DC converters within the ring network Summing these values ​​yields the total output power of the offshore new energy DC / DC converters within the ring network. ,Right now: （1-2） Step 1.2 includes: Based on the platform load power collected by the ring network controller through the platform load DC / AC sub-controller, this is the AC output power of the platform load DC / AC inverter. Considering the platform load DC / AC inverter efficiency At that time, the platform load DC / AC inverter output AC power Equal to the DC input power of the platform load DC / AC inverter Platform load DC / AC inverter efficiency The product of, i.e.: （1-3） AC power output from n platform load DC / AC inverters Summing these values ​​yields the total DC input power of the DC / AC inverters within the ring network's platform load. for: （1-4）。 6. The control method according to claim 5, characterized in that, Step 1.3 includes: Step 1.3.1 Determine the input and output power of each caisson energy storage bidirectional DC / DC converter. : Since the input and output power of each underwater caisson drainage energy storage power station includes: the power of the integrated water pump / hydro turbine generator. With the output power of the water-rotating generator The sum of the input power from the input and output terminals of a caisson energy storage bidirectional DC / DC converter ,Right now: （1-5） Step 1.3.2 Determine the input and output power of several caisson energy storage bidirectional DC / DC converters. : According to equations (1-1) and (1-4), when the power supply and load power of the ring network are unbalanced, the total output power of the offshore new energy DC / DC converter in the ring network is... With the total platform load DC / AC inverter DC input power The difference is achieved by adjusting the input and output power of several caisson energy storage bidirectional DC / DC converters. To absorb or release power in the ring network: when To ensure a balance between power supply and load within the ring network, the DC water pump in the caisson energy storage system was activated, consuming power. Power is absorbed into the ring network through the input and output terminals of several caisson energy storage bidirectional DC / DC converters. ,Right now: （1-6） Based on equation (1-5), the input and output power of several caisson energy storage bidirectional DC / DC converters is obtained, and the power absorbed by the ring network is obtained. : （1-7） when At that time, in order to ensure the balance between power supply and load power within the ring network, the DC generator of the caisson energy storage turbine is started to generate power output. Power is released to the ring network through the input and output terminals of several caisson energy storage bidirectional DC / DC converters. ,Right now: （1-8） Based on equation (1-5), the power released from the input and output terminals of several caisson energy storage bidirectional DC / DC converters to the ring network is obtained. : （1-9） in, For several units or seats, Integers; ; Input power to several caisson energy storage bidirectional DC / DC converters; Output power for several caisson energy storage bidirectional DC / DC converters; Output power for several caisson energy storage water body rotary generators; Step 1.3.3 Determine the total output power of the water-based rotary generator. : Make full use of the water-rotating generator power generation resources of the underwater caisson drainage energy storage power stations within the ring network, and increase the output power of the n water-rotating generators in the n underwater caisson drainage energy storage power stations. Summing these values ​​yields the total output power of the water-based rotating generator. ,Right now: （1-10） Step 1.3.4 Determine the power suppression power for the balance between ring network power supply and load power: Step 1.3.4.1 Perform rapid suppression of power imbalance fluctuations within the short-term fluctuating ring network: With the total output power of marine new energy DC / DC converters And the total platform load DC / AC inverter DC input power Changes in demand cause fluctuations in the power supply and load balance within the ring network. When the power supply of the ring network is balanced with the load power, let the power supply include the output power of each water-based rotating generator. ,Right now: （1-11） Based on equation (1-5), the input and output power of each caisson energy storage bidirectional DC / DC converter is controlled by the caisson energy storage sub-controller. Utilizing the rapid response characteristics of water-based rotating generators, such as flywheel energy storage and wind power generation, when power imbalances and fluctuations occur, the output power of the water-based rotating generator can be adjusted. Based on this, increase or decrease the power, that is: （1-12） The output power adjustment range of the water-based rotating generator is as follows: It can quickly suppress instantaneous power imbalance fluctuations within the ring network. ; Because each water-rotating generator outputs power All components participate in power supply, thus ensuring a consistent output power from the total water-based rotating generator during power balance within the ring network. When sudden power imbalance fluctuations occur in the ring network, the water-based rotating generator, with its characteristics of power generation similar to flywheel energy storage and the fast power response speed of wind power generation, participates in the output power of the total water-based rotating generator. Based on this, the total output power of the water-based rotating generator is controlled. Increase or decrease power to suppress fluctuations in power imbalance; Fully utilize the output power of the underwater caisson drainage energy storage power station's water-spinning generator This drives a DC water pump to drain water and increase energy storage capacity; the total output power of the water-based rotating generator is [missing information]. Subtract the output power of the water-spinning generators of several underwater submerged drainage energy storage power stations. This is equivalent to the sum of the power generated by the remaining water-based rotating generators in the underwater caisson drainage energy storage power station, even without the integrated water pump / hydropower generator in operation. ,Right now: （1-13） Step 1.3.4.2 Suppress power imbalance within the ring network at a medium-term fluctuation scale: Taking full advantage of the large capacity of each underwater caisson drainage energy storage power station, when the power supply and load power are balanced within the ring network, power is absorbed or released through the input and output of the pumps / hydro turbine generators of several underwater caisson drainage energy storage power stations, according to equation (1-12). The output power of the water-rotating generator, which belongs to several underwater submerged drainage energy storage power stations, is similar to that of the other two. cooperation, Input and output power through several caisson energy storage bidirectional DC / DC converters Right now: （1-14） And according to formula (1-6) or formula (1-8), in the underwater caisson drainage energy storage power station corresponding to the absence of a water pump / hydropower generator in operation, the sum of the output power of all remaining water-body rotating generators. Thus, the power balance equation within the ring network at the medium-term fluctuation scale is obtained: when At that time, we obtained: （1-15） when The operating power absorbed by the pumps / hydro-turbine generators of several underwater caisson drainage energy storage power stations is as follows: Stop the water body rotation generator output power The sum of the power outputs is generated by rotating the generator in the remaining water body. With the cooperation of several caisson energy storage bidirectional DC / DC converters, the input power is... The remaining y caisson energy storage bidirectional DC / DC converters release power at their input and output terminals. ,Right now: （1-16） To mitigate fluctuations in the power supply and load balance within the ring network; when hour, (1-17) when At that time, the power output of the underwater caisson drainage energy storage power station corresponding to the integrated pump / turbine generator of the underwater caisson drainage energy storage power station was released. Total output power of water-based rotating generator With coordinated regulation, the input and output power is controlled by several caisson energy storage bidirectional DC / DC converters. And the remaining power released from the input and output terminals of the bidirectional DC / DC converter for energy storage in the caisson To smooth out fluctuations in the power supply and load balance within the ring network; in, For the remaining underwater caisson drainage energy storage power stations that do not have integrated pump / hydro turbine generators in operation, the input and output power of all caisson energy storage bidirectional DC / DC converters; For the remaining underwater caisson drainage energy storage power stations where no integrated pump / hydropower generator is in operation, the output power of the bidirectional DC / DC converter at the input and output terminals of the caisson energy storage is released at this time. scope Input / output power release of the integrated water pump / hydro turbine generator Greater than the output power of the water-based rotating generator ,Right now: Due to the total output power of the water-based rotating generator Subtract the output power of the water-spinning generators of several underwater submerged drainage energy storage power stations. This equals the output power of the water-rotating generator when the integrated water pump / hydropower generator is not operating at its rated power. ,Right now: （1-18）。 7. The control method according to claim 6, characterized in that, Step 1.4 includes: according to Output power for marine new energy DC / DC converters; For the total input power of marine renewable energy; The total platform load is the DC / AC inverter's DC input power. Input and output power for each caisson energy storage bidirectional DC / DC converter; Ring network line length, total maximum power of new energy sources Total load maximum power The lower limit input voltage of the DC / AC inverter power supply for each platform load. Maximum withstand voltage of new energy power generation system The upper limit of the voltage that the system can withstand. First, the ring network controller reads the input power of all offshore new energy DC / DC converters. The MAX function is used to find the maximum input power of the offshore renewable energy DC / DC converter within the ring network. ,Right now: （1-19） And based on the maximum input power of the offshore new energy DC / DC converter The corresponding output voltage of the offshore new energy DC / DC converter Maximum voltage withstand capability for offshore new energy power generation units With safety system The product of these values ​​is less than the upper limit of the voltage the system can withstand. Right now: （1-20） Step 1.4.1 Determine the series current of the ring network : Based on the maximum input power of offshore new energy DC / DC converters With conversion efficiency The product of these two factors, and then the output voltage of the corresponding offshore new energy DC / DC converter. The ratio yields the series current of the ring network. : （1-21） in, The safety factor ranges from 80% to 99%. ; This is the maximum voltage that the offshore new energy power generation unit can withstand. Maximum input power for offshore new energy DC / DC converters The corresponding output voltage of the marine new energy DC / DC converter; Step 1.4.2 Determine the output voltage of each offshore new energy DC / DC converter. : The ring network controller monitors the input power of each offshore renewable energy DC / DC converter in real time. With conversion efficiency The product of these is then combined with the series current of the ring network. The ratio yields the output voltage of each offshore new energy DC / DC converter. ,Right now: （1-22） Based on equation (1-22), we obtain: （1-23） Step 1.4.3 Determine the total output voltage of the offshore new energy DC / DC converter within the ring network. : The output voltage of each offshore new energy DC / DC converter is given by equation (1-23). Summing yields the total output voltage of the offshore new energy DC / DC converter. ,Right now: （1-24） Among them, the maximum voltage withstand capability of n offshore renewable energy power generation systems The sum is less than the upper limit of the voltage that the system can withstand. ,Right now ; Step 1.5 includes: The total output power of the offshore new energy DC / DC converter is determined in real time by the ring network controller according to equation (1-2). Each caisson energy storage bidirectional DC / DC converter absorbs or releases power at its input and output. Equation (1-4) represents the total platform load DC / AC inverter DC input power. And the constraint parameters within the ring network, calculated and analyzed: Step 1.5.1 When Based on equation (1-6), we obtain: （1-25） At this time, the input voltage of several caisson energy storage bidirectional DC / DC converters is... Equivalent to the input and output power absorbed by several caisson energy storage bidirectional DC / DC converters Based on equation (1-21), the series current of the ring network The ratio is thus obtained: （1-26） Step 1.5.2 When Based on equation (1-8), we obtain: （1-27） Therefore, the output voltage of several caisson energy storage bidirectional DC / DC converters is... Equivalent to the input-output power release of several caisson energy storage bidirectional DC / DC converters Based on equation (1-21), the series current of the ring network The ratio is thus obtained: （1-28） Step 1.5.3 When When the total output power of the offshore new energy DC / DC converter within the ring network The output is zero, that is: To ensure a balance between the ring network power supply and the load power, the ring network power supply capacity is set to... These are respectively equal to the total platform load DC / AC inverter input DC power The sum equals the input-output power released by several caisson energy storage bidirectional DC / DC converters. ,Right now Therefore, the output voltage of several caisson energy storage bidirectional DC / DC converters is... Equal to the maximum withstand voltage of n offshore renewable energy power generation units according to equation (1-20) With safety system The product of these two values ​​is less than the upper limit of the voltage the system can withstand. ,Right now: （1-29） Based on equations (1-28) and (1-29), the power supply through the ring network is calculated. Output voltage of several caisson energy storage bidirectional DC / DC converters The ratio yields the series current of the ring network. : （1-30） in, Each caisson energy storage bidirectional DC / DC converter absorbs or releases power to the ring network at its input and output terminals. 1) When the input power of the caisson energy storage bidirectional DC / DC converter is at the input and output terminals When absorbing power into the ring network, the input power at the input and output terminals of the caisson energy storage bidirectional DC / DC converter is... DC power generation for water body rotation Power requirements of DC water pumps The sum is: ; Among them, when the DC water pump requires power Greater than the power output of DC power generation by water rotation At that time, that is: Input power at the input and output terminals of the caisson energy storage bidirectional DC / DC converter and input voltage Absorb power into the ring network; conversely, release power into the ring network. ; 2) When the output power of the input and output terminals of the caisson energy storage bidirectional DC / DC converter is... In the process of releasing power to the ring network At that time, the caisson energy storage bidirectional DC / DC converter outputs power through the hydro turbine DC power generation. The output power of the bidirectional DC / DC converter with caisson energy storage is obtained from the input and output terminals. At this time, the output power of each caisson energy storage bidirectional DC / DC converter at the input and output terminals is... It generates electricity by rotating water generators. Integrated water pump / hydro turbine generator set with DC power generation capacity The sum of these values ​​releases power into the ring network; as data accumulates, iterative updates using self-learning AI technology provide a better function model, ensuring the input and output voltage of each caisson energy storage bidirectional DC / DC converter is optimized. At the optimal value; among which, ; The input and output voltages of the pumps / hydropower generators in each underwater caisson drainage energy storage power station; the input and output power absorbed or released by the pumps / hydropower generators in each underwater caisson drainage energy storage power station and the corresponding input and output voltages of the bidirectional DC / DC converters in the caisson energy storage system. The relationship is directly proportional, meaning that the input and output power absorbed or released by the pumps / hydropower generators of each underwater submerged drainage energy storage power station is proportional to the power generated. The increase corresponds to the bidirectional input and output voltage of the caisson energy storage bidirectional DC / DC converter. Increased synchronously.

8. The control method according to claim 7, characterized in that, Step 2 includes: Step 2.1 Determine the number of underwater caisson drainage energy storage power stations Remainder Power : Input and output power are achieved through several caisson energy storage bidirectional DC / DC converters. Divide by the rated power of the DC water pump or turbine DC generator Output power of water-rotating generator The sum of the power, the quotient obtained The number and surplus power of the integrated pump / turbine generator units in the underwater caisson drainage energy storage power station under rated input and output power conditions. ,Right now: （2-1） After transformation using equation (2-1), we obtain: （2-2） Among them, the rated power of DC water pumps or DC power generation of each underwater caisson drainage energy storage power station within the ring network is... They are all equal; The number of pumps / hydro turbine generators put into operation in underwater caisson drainage energy storage power stations under rated input and output power conditions; The rated input and output power of the bidirectional DC / DC converter for caisson energy storage is equal to the rated power of the DC pump or DC generator of the underwater caisson drainage energy storage power station. The output power of the water-rotating generator in the same underwater caisson drainage energy storage power station sum; Remainder power; Step 2.2 Determine the allocated rated power for each unit Input and output voltages of a caisson energy storage bidirectional DC / DC converter under input and output conditions Remainder Power Input and output voltages of caisson energy storage bidirectional DC / DC converter under certain conditions : Based on equations (1-26), (1-28), and (2-2), we obtain Due to the series current in the ring network They are equal, therefore we have the following equation: （2-3） Therefore, the rated power of the input and output of each caisson energy storage bidirectional DC / DC converter is related to... Input and output power of several caisson energy storage bidirectional DC / DC converters The ratio is compared with the input and output voltages of several caisson energy storage bidirectional DC / DC converters. The product of and is used to allocate the rated power of each unit. Input and output voltages of a caisson energy storage bidirectional DC / DC converter under input and output conditions ,Right now: （2-4） Same remainder power Input and output power of several caisson energy storage bidirectional DC / DC converters The ratio is compared with the input and output voltages of several caisson energy storage bidirectional DC / DC converters. The product of and gives the remainder power. Input and output voltages of caisson energy storage bidirectional DC / DC converter under certain conditions ,Right now: （2-5） Step 2.3 Determine the equation for the balance between ring network power supply and load power: According to formula (2-1) Then the remainder power Through A submerged caisson drainage energy storage power station with DC power generation capacity of DC water pumps or turbines The output power of the water-rotating generator in the same underwater caisson drainage energy storage power station The sum of the remainders and power The power output is regulated and is less than the rated power of the DC power generation of the DC water pump or turbine. With the output power of the water-rotating generator The sum is: （2-6） Therefore, based on the formula get: （2-7） Based on equations (2-7), (2-2), and (2-6), we obtain: （2-8） （2-9） Among them, based on equation (1-12), we obtain ; Therefore, based on equations (2-8) and (2-9), through The underwater caisson drainage energy storage power station inputs and outputs rated power via a corresponding caisson energy storage bidirectional DC / DC converter. With regulation The input-output residual power of the caisson energy storage bidirectional DC / DC converter in the underwater caisson drainage energy storage power station. ,as well as The underwater caisson drainage energy storage power station outputs power from the water-rotating generator via the corresponding caisson energy storage bidirectional DC / DC converter input and output terminals. Summation power The sum equals the total platform load DC / AC inverter DC input power within the ring network. Total output power of marine new energy DC / DC converters within the ring network The difference is used to achieve a balance between the ring network power supply and the load power; Therefore, based on equation (2-9), the power released to the ring network by the underwater caisson drainage energy storage power station is related to the total output power of the offshore new energy DC / DC converter. Combining these, we obtain the equation for ring network power supply and load power balance: （2-10） Step 2.3.1 When the ring network power supply and load power are balanced At that time, due to The underwater caisson drainage energy storage power station inputs and outputs power through the corresponding caisson energy storage bidirectional DC / DC converter. Relatively constant, based on equations (2-6) and (2-9) through regulation The input-output residual power of the bidirectional DC / DC converter for underwater caisson drainage energy storage power station. and The underwater caisson drainage energy storage power station outputs power from a water-based rotating generator via the corresponding caisson energy storage bidirectional DC / DC converter input and output terminals. Summation power This coordination achieves a balance between ring network power supply and load power; among which, Input-output remainder power The corresponding underwater caisson drainage energy storage power station; The number of remaining underwater caisson drainage energy storage power stations corresponding to those without integrated pump / hydro turbine generator units in operation; Step 2.3.2 When At that time, through regulation The underwater submerged drainage energy storage power station and the corresponding water-body rotating generator output power sum equal and through Taiwan-type caisson energy storage bidirectional DC / DC converter input and output power ; will Substituting into equation (2-2), we get: ; （2-11） According to equation (2-11), the input and output power of several caisson energy storage bidirectional DC / DC converters It is by Submersible caisson drainage energy storage power station pump / hydro turbine generator integrated unit rated input and output power The power output of all underwater submerged drainage energy storage power stations is via water-rotating generators. The sum of these factors balances the power supply and load power within the ring network; among them, Input and output power of several caisson energy storage bidirectional DC / DC converters; This represents the total output power of the water-based rotating generator. For underwater caisson drainage energy storage power stations without integrated pumps / hydropower generators in operation, the sum of the power generated by the corresponding water-rotating generators is considered; that is: （2-12） If n underwater submerged drainage energy storage power stations are connected within the ring network, what is the total number of power stations? Therefore, the total number of underwater caisson drainage energy storage power stations within the ring network is... Subtract the number of underwater submerged drainage energy storage power stations under rated input and output conditions for integrated pump / hydro turbine generator units. Then, the power is calculated by adding the input and output remainders. Corresponding underwater caisson drainage energy storage power station The difference is equal to the number of remaining underwater caisson drainage energy storage power stations corresponding to the pumps / hydro turbine generators that did not participate in the operation of the power input / output pumps. ,Right now: ; The number of underwater submerged caisson drainage energy storage power stations for integrated pump / hydro turbine generators under rated input and output conditions. It is an integer; ; The total number of underwater submerged drainage energy storage power stations within the ring network. It is an integer; The number of remaining underwater caisson drainage energy storage power stations corresponding to those that did not participate in the operation of the rated power input / output water pump / hydro turbine generator integrated unit. It is an integer; Since the water-body rotating generator of each underwater caisson drainage energy storage power station within the ring network is in power generation mode, even if the DC pump or turbine DC generator input and output power is... It equals zero, that is: The water-based rotating generator is still generating electricity, and the output power of the water-based rotating generator is controlled through the caisson energy storage sub-controller. The magnitude is adjusted, and the fast power response speed is utilized to participate in the suppression of disturbance-free power imbalance fluctuations within the ring network. Therefore, the input and output power of all caisson energy storage bidirectional DC / DC converters are... This corresponds to the presence of several water-based rotating generators participating in power generation and output. The aim is to regulate the output power of the water-based rotating generator. The increase or decrease, that is, in Adjusting the range quickly suppresses short-term power imbalance fluctuations within the ring network; while the output power of each water-rotating generator... All are less than the rated power of DC power generation for DC water pumps or turbines. ,Right now ;in, Input and output power of several caisson energy storage bidirectional DC / DC converters; This represents the total output power of the water-based rotating generator. The number of pumps / hydro turbine generators put into operation in underwater caisson drainage energy storage power stations under rated input and output power conditions; Input and output power for several caisson energy storage bidirectional DC / DC converters; For several underwater caisson drainage energy storage power stations, the DC water pump load power or the DC power generation power of the turbines is used; For each underwater caisson drainage energy storage power station, specify the DC water pump load power or the DC power generation power of the turbine. The rated input and output power of the bidirectional DC / DC converter for caisson energy storage is equal to the rated power of the DC pump or DC generator of the underwater caisson drainage energy storage power station. The output power of the water-rotating generator in the same underwater caisson drainage energy storage power station sum; The output power of the water-rotating generator in several underwater caisson drainage energy storage power stations; For several underwater caisson drainage energy storage power stations, the DC water pumps or turbines that generate DC power do not participate in the input and output power of the ring network. The output power of the water-rotating generator in the underwater caisson drainage energy storage power station is... Calculate the sum of power.

9. The control method according to claim 8, characterized in that, Step 2.4 includes: determining the priority order for putting underwater caisson drainage energy storage power stations into operation. use The sorting function stores the remaining power generation capacity of n underwater submerged drainage energy storage power stations according to demand. Sort; Step 2.4.1 The remaining power generation capacity of the underwater submerged drainage energy storage power station during the process of absorbing power from the ring network by the water pump is sorted from smallest to largest as follows: Therefore, the ring network controller controls the input and output power of several caisson energy storage bidirectional DC / DC converters. Absorbing power from the ring network In this case, priority is given to underwater caisson drainage energy storage power stations with large water storage capacity. The remaining power generation capacity is then stored by utilizing water pumps to drain water and absorb power from the ring network. Small, based on this The sorting function stores the remaining power generation capacity of n underwater submerged drainage energy storage power stations. Sorting, that is: Sequential functions from smallest to largest: （2-13） This results in an ascending order of sorting: （2-14） in, To store the remaining power generation capacity of the first underwater caisson drainage energy storage power station To store the remaining power generation capacity of the second underwater caisson drainage energy storage power station. To store the remaining power generation capacity for the nth underwater submerged drainage energy storage power station. , Integers; The ring network controllers are selected sequentially from the fewest to the most numerous in the ring network: The underwater submerged drainage energy storage power station with the smallest remaining power generation capacity is ranked as follows. It is the second smallest underwater submerged drainage energy storage power station in terms of remaining power generation capacity. To store the largest remaining power generation capacity of the underwater caisson drainage energy storage power station, the input and output power of several caisson energy storage bidirectional DC / DC converters are... Absorbing power from the ring network At that time, according to formula (2-8) The number of underwater submerged drainage energy storage power stations is based on the remaining power generation capacity stored. Select the corresponding underwater caisson drainage energy storage power station from smallest to largest, and then select the corresponding caisson energy storage bidirectional DC / DC converter input and output terminals rated power. With regulation The input-output residual power of the caisson energy storage bidirectional DC / DC converter in the underwater caisson drainage energy storage power station. ,as well as The underwater caisson drainage energy storage power station outputs power from the water-rotating generator via the corresponding caisson energy storage bidirectional DC / DC converter input and output terminals. Summation power In coordination, power is absorbed from the ring network to achieve a balance between the ring network power supply and the load power; Step 2.4.2: When the turbine releases power, the remaining power generation capacity of the underwater caisson drainage energy storage power station is sorted from largest to smallest: Similarly, the ring network controller controls the input and output power of several caisson energy storage bidirectional DC / DC converters. Release power generation to the ring network In this case, priority should be given to underwater caisson drainage energy storage power stations with small water storage capacity, as the power generated by the sequential release of power through turbines using the potential energy of the water depth is relatively large, thus storing the remaining power generation capacity. Larger, based on this The sorting function stores the remaining power generation capacity of the n underwater sump drainage energy storage power station. That is to Sort from largest to smallest, thus obtaining: （2-15） The ring network controllers are selected from the largest to the smallest values ​​in the ring network: The underwater submerged drainage energy storage power station with the largest remaining power generation capacity is ranked as follows. It is the second largest underwater submerged drainage energy storage power station in terms of storing remaining power generation capacity. This refers to an underwater caisson drainage energy storage power station with the smallest remaining power generation capacity; the input and output power of several caisson energy storage bidirectional DC / DC converters are... Release power to the ring network At that time, according to formula (2-8) Number of underwater submerged drainage energy storage power stations and their remaining power generation capacity Select the corresponding underwater caisson drainage energy storage power stations from largest to smallest, and then select the corresponding caisson energy storage bidirectional DC / DC converters with rated output power at the input and output terminals. With regulation The input-output residual power of the caisson energy storage bidirectional DC / DC converter in the underwater caisson drainage energy storage power station. ,as well as The underwater caisson drainage energy storage power station outputs power from a water-based rotating generator via the corresponding caisson energy storage bidirectional DC / DC converter input and output terminals. Summation power The sum equals the total platform load DC / AC inverter DC input power within the ring network. Total output power of marine new energy DC / DC converters within the ring network The difference is used to achieve a balance between the ring network power supply and the load power.

10. The control method according to claim 9, characterized in that, Step 3.1 includes: Based on the collected input power of each marine new energy DC / DC converter Based on equations (1-1) and (1-2), the total output power of the offshore new energy DC / DC converter within the ring network is obtained. ; Meanwhile, the ring network controller predicts the AC output power of the DC / AC inverter based on the historical load of the platform within the ring network during the same period. Demand data is used to convert the platform load DC / AC inverter efficiency according to equation (1-3). At that time, the platform load DC / AC inverter predicts the DC input power. Equal to the platform load DC / AC inverter output AC power The reciprocal of the efficiency of the DC / AC inverter with respect to the platform load The product of, i.e.: (3-1) Based on equation (1-4), the predicted output AC power of n platform load DC / AC inverters is calculated. Summing these values ​​yields the total platform load within the ring network and the predicted DC input power of the DC / AC inverter. Demand, among which ; Based on data analysis and equation (1-2), the total output power of the offshore new energy DC / DC converter within the ring network is given. The predicted DC input power of the DC / AC inverter and the total platform load within the ring network. The ratio of demand to power ratio coefficient is obtained. ,Right now: （3-2） Among them, through the power ratio coefficient It can reflect the power of new energy power generation units and load demand within the ring network. Furthermore, when the power of new energy power generation units exceeds the load power, it can be used to calculate the power ratio coefficient. And according to equation (1-24), the total output voltage of the marine new energy DC / DC converter It can distribute the input DC voltage to each platform load DC / AC inverter. ; Step 3.2 includes: To ensure the load power demand during black start-up of the ring network, the ring network controller uses equation (3-2) to control the total power generation of new energy sources. Predicted DC input power of DC / AC inverters within the ring network's total platform load Size comparison analysis: Step 3.2.1 When the power ratio coefficient This indicates the total power generation capacity of new energy sources within the ring network. The predicted DC input power of the DC / AC inverter is greater than or equal to the total platform load within the ring network. ,Right now: ; Based on step 1.4, the series current of the ring network is obtained according to equation (1-21). Equation (1-22) Output voltage of each offshore new energy DC / DC converter The total output voltage of the offshore new energy DC / DC converter within the sum of equations (1-24) ring network ; Due to the series current in the ring network Same, therefore To ensure that each platform load DC / AC inverter is allocated DC input power To maximize the power output of all caisson energy storage bidirectional DC / DC converters at both input and output terminals. It is zero, that is It is in a short-circuit state, at which time the total output voltage of the offshore new energy DC / DC converter is... The ring network power supply voltage during black start-up And the input DC voltage is distributed with the total platform load DC / AC inverter. Equal, that is Therefore, each load DC / AC sub-controller is based on the series current of the ring network. Predicted DC input power of each platform load DC / AC inverter Power ratio coefficient Calculate the corresponding distributed input DC voltage for the DC / AC inverter of this platform load. ,Right now: （3-3） Therefore, based on equation (3-3), the input DC voltage is obtained by allocating DC / AC inverters to each platform load. ,Right now: （3-4） At this time, the load DC / AC sub-controller receives the platform load DC / AC inverter distribution input DC voltage issued by the corresponding ring network controller. Data is used to control the corresponding input DC voltage allocated to the DC / AC inverters of this platform's load. Current in series with ring network The product of these two values ​​yields the DC input power allocated to the platform load DC / AC inverter. ; At this point, the DC input power is allocated to the DC / AC inverter of each platform load. All achieved a predicted AC output power of the DC / AC inverter greater than or equal to the corresponding platform load. It is also the load forecast power. ,Right now: （3-5） This ensures the total output power of the marine new energy DC / DC converter within the ring network. The predicted DC input power of the DC / AC inverter is greater than the total platform load within the ring network. ,Right now At the same time, it satisfies the predicted AC output power of each load DC / AC inverter at the black start moment. need; Step 3.2.2 When the power ratio coefficient This demonstrates that the total output power of the offshore new energy DC / DC converter within the ring network can be obtained based on equation (1-2). The predicted DC input power of the DC / AC inverter is less than the total platform load within the ring network. ,Right now Determine the total power supply of the ring network. Total output voltage of offshore new energy DC / DC converter Ring network power supply voltage at black start Distribute the input DC voltage to each platform load DC / AC inverter. Due to the series current in the ring network Same, therefore ; Step 3.2.2.1 Considering the black start of the ring network, the predicted AC input power of the DC / AC inverter should meet the total platform load within the ring network. The requirement is to ensure that each platform load DC / AC inverter is allocated DC input power. The DC input power of the DC / AC inverter exceeds the predicted DC input power of each platform load. ,Right now: At this time, the input and output power of several caisson energy storage bidirectional DC / DC converters are... Release power to the ring network According to equation (2-9) Number of underwater submerged drainage energy storage power stations and their remaining power generation capacity Select the corresponding underwater caisson drainage energy storage power stations from largest to smallest, corresponding in order to the rated output power of the input and output terminals of the caisson energy storage bidirectional DC / DC converter. Harmony and Regulation The input-output residual power of the caisson energy storage bidirectional DC / DC converter in the underwater caisson drainage energy storage power station. ; due to the residual power in equations (2-1) and (2-2) Less than the rated input and output power of the caisson energy storage bidirectional DC / DC converter ,Right now: To ensure that the output power of the ring network is greater than the power consumption of the load during black start, the residual power is set according to equation (2-9). and The underwater caisson drainage energy storage power station outputs power from a water-based rotating generator via the corresponding caisson energy storage bidirectional DC / DC converter input and output terminals. Summation power Equal to the rated input and output power of the caisson energy storage bidirectional DC / DC converter ,Right now: Thus we obtain Number of underwater caisson drainage energy storage power stations; caisson energy storage; bidirectional DC / DC converter; input / output rated power. Equal to the total platform load DC / AC inverter predicted DC input power With the total output power of the marine new energy DC / DC converter The difference is: （3-6） Therefore, the ring network power supply at the black start time can be obtained according to equation (3-6). equal The underwater caisson drainage energy storage power station has corresponding caisson energy storage bidirectional DC / DC converters with rated power output at the input and output terminals. With the total output power of the marine new energy DC / DC converter The sum of these values ​​represents the total platform load, and the predicted DC input power of the DC / AC inverter is also included. Power supply, i.e.: （3-7） in, This represents the total power supply of the ring network; The underwater caisson drainage energy storage power station outputs power from a water-based rotating generator via the corresponding caisson energy storage bidirectional DC / DC converter input and output terminals. Summation power Much smaller than the rated input and output power of the caisson energy storage bidirectional DC / DC converter. ; The total output power of the water-rotating generator; The DC power generation capacity of the turbine in the integrated pump / turbine generator of several underwater caisson drainage energy storage power stations; Output power at the input and output terminals of several caisson energy storage bidirectional DC / DC converters; The rated power output of the bidirectional DC / DC converter for caisson energy storage includes the rated DC power generation of the turbine in the integrated pump / turbine generator of the underwater caisson drainage energy storage power station. Output power of water-based rotating generator ; for The input and output residual power of the bidirectional DC / DC converter for the submerged caisson drainage energy storage power station is based on equation (2-6) and includes: ; Step 3.2.2.2 Based on this, the output voltage of each marine new energy DC / DC converter is obtained according to equation (1-22). Equation (1-24) yields the total output voltage of the marine new energy DC / DC converter within the current ring network. ; Step 3.2.2.3 Determine the total power supply voltage of the ring network. : Based on equation (3-7) and step 2, determine the underwater caisson drainage energy storage power station. Quantity and priority of work order, obtained Series current with ring network Equal to, and equation (1-24) yields the total output voltage of the current marine new energy DC / DC converter within the ring network. Summing these values ​​yields the total supply voltage of the ring network under black-start conditions. ,Right now: （3-8） Ring network power supply voltage at black start This is equivalent to the DC / AC inverter distributing the input voltage to provide the total platform load within the ring network. Thus, the ring network supply voltage at the black start moment is obtained. The DC / AC inverter's predicted DC input voltage exceeds the load of each platform. Sum of voltages ,Right now: （3-9） Step 3.2.2.4 Based on equation (3-7), calculate the total power supply of the ring network. The series current of the ring network at the black start moment is obtained from equation (3-9) and the principle of electrical work. Right now: （3-10） Therefore, the relevant parameters in equation (3-10) can satisfy the conditions for the black start time; Step 3.2.2.5 Calculate the input DC voltage allocated to each platform load DC / AC inverter. : Predicted output AC power of each platform load DC / AC inverter based on predictive analysis Combined with equation (2-16), the predicted DC input power of each platform load DC / AC inverter within the ring network is obtained. ; And predict the DC input power of the DC / AC inverters of the n platform loads in the predictive analysis. Summation, i.e.: （3-11） The predicted DC input power of the DC / AC inverter within the ring network at the moment before black start is obtained from the predictive analysis. need; Based on equation (3-9) and the predictive analysis of the DC / AC inverter of each platform load in the ring network, the DC input power is predicted. The predicted DC input power of the DC / AC inverter and the total platform load within the ring network. The ratio, and then compared with the ring network power supply voltage at the moment of black start. The product of these factors is used to allocate the DC input voltage to each platform load DC / AC inverter. ,Right now: （3-12） Therefore, we can conclude that: （3-13） The ring network series current obtained according to equation (36) Since the loads are equal within the ring network, the DC / AC inverters of each platform are allocated the corresponding input DC voltage. Current in series with ring network The product equals the DC input power allocated by the DC / AC inverter to the platform load. Simultaneously, according to equation (3-9), the DC input power is distributed to the DC / AC inverter of this platform load. Platform load DC / AC inverter efficiency The product of these values ​​is greater than the predicted AC output power of the DC / AC inverter for the corresponding platform load. ,Right now This ensures the predictive assessment of AC load power during black start. The demand.

11. The control method according to claim 10, characterized in that, Step 4.1 includes: Step 4.1.1 Determine the equation for the balance between ring network power supply and load power: To quickly respond to power imbalance fluctuations caused by changes in ring network power supply and load power, and given the relatively small capacity of the water-based rotating generator and its rapid response to power changes, the sub-controller of the caisson energy storage unit controls the input and output terminals of each caisson energy storage bidirectional DC / DC converter to absorb or release power when the ring network power supply and load power are balanced. This includes the output power of the water-rotating generator. Power is output by rotating the generator in the water. Based on this, the power imbalance fluctuations within the ring network can be quickly suppressed by increasing or decreasing the power supply or load power. Therefore, when the power supply and load power are balanced within the ring network, the equation for the power supply and load power balance of the ring network can be obtained according to equations (2-11), (2-2), (1-12), and (2-6): （4-1） in, Input and output power of several caisson energy storage bidirectional DC / DC converters; This represents the total output power of the water-based rotating generator. The number of pump / turbine generator units put into operation in an underwater caisson drainage energy storage power station under rated input and output power conditions. Integers; DC power generation for several underwater caisson drainage energy storage power stations; The rated input and output power of the DC water pump or DC power generator of each underwater caisson drainage energy storage power station; The output power of the water-rotating generator in several underwater caisson drainage energy storage power stations; In addition to the DC power generation of several underwater caisson drainage energy storage power stations' DC water pumps or turbines, The output power of the underwater submerged drainage energy storage power station's water-rotating generator Sum of power; Let n underwater submerged drainage energy storage power stations be connected within the ring network, and the total number of power stations be... Therefore, the total number of underwater caisson drainage energy storage power stations within the ring network is... Subtract the number of underwater submerged drainage energy storage power stations under the rated input and output power conditions of the integrated pump / hydro turbine generator. ,as well as A single underwater caisson drainage energy storage power station is equivalent to the remaining number of underwater caisson drainage energy storage power stations corresponding to pumps / hydro turbines that do not participate in the operation of power input / output. ,Right now: ;in, The total number of underwater submerged drainage energy storage power stations within the ring network. It is an integer; The remaining number of underwater caisson drainage energy storage power stations corresponding to those that are not involved in the operation of the rated power input / output water pump / hydro turbine generator integrated unit. It is an integer; The purpose of the underwater caisson drainage energy storage power station is to regulate the input, output, and residual power of the bidirectional DC / DC converter for caisson energy storage. , It is an integer; Equation (4-1) shows that when the power supply of the ring network is balanced with the load power: Step 4.1.2 When the total output power of the offshore new energy DC / DC converter within the ring network... Equal to the total platform load DC / AC inverter DC input power within the ring network ,Right now At this time, based on equations (2-2) and (2-6), Substituting this into equation (4-1) for ring network power supply and load power balance, we get: ； get ; make At that time, we obtained: （4-2） At this time, the caisson energy storage sub-controller controls... The input power of the DC water pump in the submerged caisson drainage energy storage power station's integrated pump / hydro turbine generator unit. Negative, absorbs the same The output power of the underwater submerged drainage energy storage power station's water-rotating generator At the same time, absorb the remaining quantity Summation power Again with The output power of the underwater submerged drainage energy storage power station's water-rotating generator sum; Consider the remaining quantity Summation power and The output power of the underwater submerged drainage energy storage power station's water-rotating generator The sum of these values ​​is greater than the rated input and output power of the integrated pump / hydropower generator of the submerged caisson drainage energy storage power station. ,Right now: At that time, appropriately reduce the remaining quantity. Water-based rotating generator output power Sum of power Therefore, we can conclude that: This shows The input power of the DC water pump in the submerged caisson drainage energy storage power station's integrated pump / hydro turbine generator unit. absorb The output power of the underwater submerged drainage energy storage power station's water-rotating generator At the same time, it also absorbs the remaining quantity Water-based rotating generator output power Summation power ,Right now: In other words, through the ring network The input power of the DC water pump in the submerged caisson drainage energy storage power station's integrated pump / hydro turbine generator unit. Power supply does work, absorbs power To ensure the balance between the ring network power supply and the load power, and at the same time to discharge The underwater submerged drainage energy storage power station increases reservoir capacity and energy storage capacity; Due to power and The sum equals ,Right now: （4-3） When the power supply and load power of the ring network are balanced, the following conclusions are drawn: On the one hand, when sudden power imbalance fluctuations occur in the ring network, based on the fast power generation response speed of the water-based rotating generator, the output power of the water-based rotating generator... Based on this, increasing or decreasing the regulating power can quickly suppress power imbalance fluctuations within the ring network; on the other hand, it can make full use of the water body rotating generator power generation resources of the underwater caisson drainage energy storage power station to drive DC water pumps to drain water and increase the energy storage capacity. Step 4.1.3 When short-term fluctuations occur in the power supply and load power within the ring network, resulting in an imbalance, the total output power of the offshore new energy DC / DC converter... DC / AC inverter DC input power greater than or less than the total platform load ,Right now or At that time, based on equation (4-1) and equation (4-3), the following equations are obtained: （4-4） According to equation (4-4), the caisson energy storage sub-controller is used for control. Number of underwater submerged drainage energy storage power stations and The sorting function sorts the input and output rated power of the corresponding integrated water pump / hydro turbine generator in sequence. and in sequence Submerged caisson drainage energy storage power station pump / hydro turbine generator integrated power input and output power The sum of these, and then combined with the total output power of the water-based rotating generator. The sum of these values, along with the corresponding bidirectional DC / DC converter for caisson energy storage, enables the input and output power. Absorbing or releasing power into the ring network For the total platform load DC / AC inverter DC input power With the total output power of the marine new energy DC / DC converter Power difference support; Therefore, when the power supply and load power of the ring network are in balance, sudden changes in the power supply and load power cause power imbalance fluctuations. Based on the relatively small capacity and rapid response of the water-based rotating generator to power changes, the ring network controller controls the output power of the total water-based rotating generator. Based on this, by controlling the sub-controllers of the submerged energy storage units in all underwater submerged drainage energy storage power stations, the output power of the water-spinning generators can be increased or decreased. Input and output power via caisson energy storage bidirectional DC / DC converter It absorbs or releases power in the ring network, quickly suppressing fluctuations in the power imbalance of the ring network; Step 4.2 includes: Step 4.2.1 Determine the series current of the ring network Output voltage of each offshore new energy DC / DC converter and the total output voltage of the offshore new energy DC / DC converter within the ring network : The ring network controller collects data from all devices within the ring network in real time, and bases this data on the input power of each new energy DC / DC converter within the ring network. Step 1.4 yields the series current of the ring network as shown in equation (1-21). Equation (1-22) Output voltage of each offshore new energy DC / DC converter The total output voltage of the offshore new energy DC / DC converter within the sum of equations (1-24) ring network ; Step 4.2.2 Adaptively adjust the input voltage of the DC / AC inverter to the platform load. : Since the ring network consists of n platform load DC / AC inverters, the DC input power of each platform load DC / AC inverter is... and output power As load demand changes, the total platform load DC / AC inverter input power within the ring network... Changes occur synchronously; among them, This refers to the DC input power of the platform load DC / AC inverter. The output AC power of the platform load DC / AC inverter is also the load power; The efficiency of the platform load DC / AC inverter is given; therefore, at a certain moment, the DC input power of the n platform load DC / AC inverters in the ring network is obtained according to the total DC input power of the platform load DC / AC inverter. The sum of these values ​​represents the total platform load DC / AC inverter DC input power. ; Due to changes in load demand, the DC input power of the platform load DC / AC inverter With output power Adjustments are made in response to changes; at this time, the load DC / AC sub-controller does not consider the efficiency of the platform load DC / AC inverter. Under loss conditions, the DC input power of the platform load DC / AC inverter at the previous moment will be... With output power Perform difference calculations to obtain the required adjustment value for the DC / AC inverter's DC input power at the platform load. Right now: （4-5） Based on equation (4-5), the differential platform load DC / AC inverter DC input power Compared to the platform load DC / AC inverter DC input power at the previous moment The sum of these values ​​yields the DC input power of the platform load DC / AC inverter that needs to be adjusted at the current moment. Right now: (4-6) in, The DC input power of the DC / AC inverter on the differential platform load can be positive or negative. The DC input power of the platform load DC / AC inverter that needs to be adjusted at the current moment; The DC input power of the DC / AC inverter is the platform load at the previous moment. The AC power output of the DC / AC inverter for the platform load at the previous moment is also the AC power consumption of the AC load at the previous moment. The current AC power output of the DC / AC inverter for the platform load is also the current AC load power consumption. And the ring network series current obtained according to equations (44) and (1-21) Adaptive adjustment of platform load DC / AC inverter input voltage ,Right now: （4-7） Therefore, the load DC / AC sub-controller adaptively adjusts the input voltage of the platform load DC / AC inverter. Control platform load DC / AC inverter DC input power To meet the current AC load power requirements need; Similarly, based on equation (4-7), the input DC voltage of the DC / AC inverter for the n platform loads in the ring network is... The sum of these values ​​represents the total platform load DC / AC inverter input DC voltage. ,Right now: （4-8） Step 4.2.3 Determine the input and output terminals of the n caisson energy storage bidirectional DC / DC converters. , Voltage and output voltage : The ring network consists of n underwater submerged drainage energy storage power stations. At that time, based on the ring network power supply and load power balance equation (4-1), the underwater caisson drainage energy storage power station is determined according to step 2. The quantity and priority of operation are determined by the input and output power of several caisson energy storage bidirectional DC / DC converters. The total output voltage of the offshore new energy DC / DC converter is obtained through step 4.2.1 by absorbing power from the ring network. Current series current of the ring network The rated input and output power of each unit is obtained by allocating it according to equations (2-4) and (2-5). Input and output voltages of caisson energy storage bidirectional DC / DC converter under certain conditions And obtain the remainder power Input and output voltages of caisson energy storage bidirectional DC / DC converter under certain conditions Equation (4-7) adaptively adjusts the input voltage of the DC / AC inverter on the platform load. The input DC voltage of the DC / AC inverter for the total platform load is obtained according to equation (4-8). And according to equation (1-12), when the input and output power of the caisson energy storage bidirectional DC / DC converter... Absorbing power from the ring network At that time, the DC water pump input power in the integrated water pump / hydro turbine generator is... The power absorbed by the ring network is thus obtained as follows: （4-9） According to equation (2-8), we get: ; Since the power absorbed into the ring network is negative according to (4-9), we can conclude that: （4-10） Due to the series current in the ring network Equal, therefore: （4-11） From equations (4-10) and (4-11), it can be seen that in When the ring network power supply and load power are balanced, the ring network controller controls each of the sub-controllers of the caisson energy storage system; among them, the remaining number The corresponding underwater submerged drainage energy storage power station's water-spinning generator power generation capacity Divide by the series current of the ring network Get the remaining quantity Corresponding output voltage of the input and output terminals of the caisson energy storage bidirectional DC / DC converter ,Right now: Therefore, the remaining quantity Corresponding output voltage of the input and output terminals of the caisson energy storage bidirectional DC / DC converter Summing yields the remaining number of underwater submerged drainage energy storage power stations corresponding to those that did not participate in the operation of the rated power input / output water pumps / hydro turbine generator units. voltage Step 4.2.3.1 Based on formula (2-14), at the rated input power of the DC water pump... Under these conditions, the remaining power generation capacity is stored sequentially from smallest to largest. Select accordingly This underwater submerged drainage energy storage power station utilizes the DC water pump input power of the corresponding integrated water pump / hydro turbine generator. Power output of water-based rotating generator The sum equals ,through The input power voltage of the caisson energy storage bidirectional DC / DC converter is at the input and output terminals. Absorb rated power into the ring network ; Step 4.2.3.2 By sorting The next A submerged caisson drainage energy storage power station that regulates the input power of the DC water pump in the integrated pump / turbine generator unit. With the voltage of the water-rotating generator The sum of them is Because the DC water pump in the integrated water pump / hydro turbine generator absorbs power from the ring network. It is negative, therefore it should be At that time, Submerged caisson drainage energy storage power station caisson energy storage bidirectional DC / DC converter input / output terminal input voltage Absorbing surplus power into the ring network ; when Time Submerged caisson drainage energy storage power station caisson energy storage bidirectional DC / DC converter input and output voltage Release surplus power to the ring network ;in, To absorb the remaining power into the ring network; The input voltage at the input and output terminals of the caisson energy storage bidirectional DC / DC converter when absorbing residual power into the ring network; To release the remaining power into the ring network; The output voltage at the input and output terminals of the caisson energy storage bidirectional DC / DC converter when releasing the remaining power to the ring network; Step 4.2.3.3 If n underwater caisson drainage energy storage power stations are connected to the ring network, the total number of power stations is... Therefore, the total number of underwater caisson drainage energy storage power stations within the ring network is... Subtract the number of underwater submerged drainage energy storage power stations under rated input and output conditions for integrated pump / hydro turbine generator units. Then, the power is calculated by adding the input and output remainders. Corresponding underwater caisson drainage energy storage power station The difference is equal to the remaining number of underwater submerged drainage energy storage power stations corresponding to the integrated water pumps / hydro turbine generators that did not participate in the operation of power input / output. ,Right now: ; The number of underwater submerged caisson drainage energy storage power stations for integrated pump / hydro turbine generators under rated input and output conditions. Integers; ; The total number of underwater submerged drainage energy storage power stations within the ring network. Integers; The remaining number of underwater caisson drainage energy storage power stations corresponding to those that are not involved in the operation of the rated power input / output water pump / hydro turbine generator integrated unit. Integers; Therefore, by controlling the remaining quantity The corresponding underwater submerged drainage energy storage power station's water-spinning generator power generation capacity The output voltage is generated by the input and output terminals of the caisson energy storage bidirectional DC / DC converter. Among them, voltage The remaining number of underwater caisson drainage energy storage power stations divided by the number of those corresponding to pumps / hydro turbines that are not involved in the operation of the rated power input / output pumps / hydro turbine generators. To obtain the remaining quantity The output voltage of the input and output terminals of the bidirectional DC / DC converter for each underwater caisson drainage energy storage power station. ,Right now: （4-12） Therefore The underwater caisson drainage energy storage power station outputs voltage through the input and output terminals of the caisson energy storage bidirectional DC / DC converter. Power release for ring network This enables rapid suppression of power balance fluctuations between the ring network power supply and the load; among which, For DC water pumps at rated input power The input voltage at the input and output terminals of the caisson energy storage bidirectional DC / DC converter under the specified conditions; The number of underwater submerged caisson drainage energy storage power stations for integrated pump / hydro turbine generators under rated input and output conditions. Integers; The power output from the input / output terminals of the caisson energy storage bidirectional DC / DC converter for the corresponding underwater caisson drainage energy storage power station that does not participate in the operation of the pump / hydro turbine generator integrated unit; The total number of underwater submerged drainage energy storage power stations within the ring network. Integers; The remaining number of underwater submerged drainage energy storage power stations corresponding to water pumps / hydro turbine generators that are not operating at their rated input / output power. Integers; Step 4.3 includes: Step 4.3.1 Determine the ring network power supply voltage Ring network series current Output voltage of offshore new energy DC / DC converter and the DC input voltage of each platform load DC / AC inverter : The ring network controller collects data from all devices within the ring network in real time, and bases this data on the input power of each new energy DC / DC converter within the ring network. Through step 1.4, the series current of the ring network is obtained according to equation (1-21). Equation (1-22) Output voltage of each offshore new energy DC / DC converter The total output voltage of the offshore new energy DC / DC converter within the sum of equations (1-24) ring network ; Step 4.3.1.1 Determine the ring network power supply voltage Rated power of each unit Input and output voltages of caisson energy storage bidirectional DC / DC converter under output conditions Sum of power Input and output voltages of caisson energy storage bidirectional DC / DC converter under certain conditions : Based on equations (1-27) and (1-28), the input and output power of the bidirectional DC / DC converter for caisson energy storage are obtained respectively. Output voltage of caisson energy storage bidirectional DC / DC converter ; Based on equation (1-27), the power balance within the ring network and the series current of the ring network are considered. Equal determination of ring network power supply voltage for: （4-13） The rated power of each unit is allocated based on equation (2-3). Input and output voltages of a caisson energy storage bidirectional DC / DC converter under input and output conditions Remainder Power Input and output voltages of caisson energy storage bidirectional DC / DC converter under certain conditions The equation yields: （4-14） The rated power of each unit is then allocated according to formula (2-4). Output voltage of caisson energy storage bidirectional DC / DC converter under output conditions ,Right now: （4-15） Similarly, the remainder power is obtained according to equation (2-5). Input and output voltages of caisson energy storage bidirectional DC / DC converter under certain conditions ,Right now: （4-16） Therefore, based on equation (2-10), the series current of the ring network... Equal to step 4.3.1.1, determine the ring network power supply voltage. The ring network power supply voltage is obtained. equal The input and output voltage of the caisson energy storage bidirectional DC / DC converter and The input and output voltage of the caisson energy storage bidirectional DC / DC converter The total output voltage of the marine new energy DC / DC converter within the ring network Then with the remaining quantity The input and output voltage of the caisson energy storage bidirectional DC / DC converter The sum of these values ​​is equal to the total platform load DC / AC inverter DC input voltage. , because: （4-17） Among them, the remaining quantity The corresponding underwater submerged drainage energy storage power station's water-spinning generator power generation capacity Divide by the series current of the ring network Get the remaining quantity Corresponding output voltage of the input and output terminals of the caisson energy storage bidirectional DC / DC converter ,Right now: Therefore, the remaining quantity Corresponding output voltage of the input and output terminals of the caisson energy storage bidirectional DC / DC converter Summing yields the remaining number of underwater submerged drainage energy storage power stations corresponding to those that did not participate in the operation of the rated power input / output water pumps / hydro turbine generator units. voltage ; Step 4.3.1.2 Determine the DC input voltage of the DC / AC inverter for each platform load. : Based on (1-21) ring network series current Equal to the DC input power of all platform loads in the current ring network DC / AC inverter This is how the DC input voltage of the DC / AC inverter for each platform load is allocated. ,Right now: Based on this, the series current of the ring network The DC input voltage of the DC / AC inverter for each platform load is obtained through allocation. To ensure the current total output power of marine new energy DC / DC converters DC / AC inverter DC input power less than the total platform load , Ring network power supply and load power balance under certain conditions; Therefore, the underwater caisson drainage energy storage power station is determined by the ring network controller through equation (4-17) and all the caisson energy storage sub-controllers according to step 2. The quantity and priority of work order, as shown in equation (2-15) at the rated output power of the hydro-turbine DC generator. Under the given conditions, the corresponding controls are as follows: Step 4.3.2.1 Store the remaining power generation capacity in descending order of size. Select accordingly This underwater submerged drainage energy storage power station utilizes the rated output power of the turbine-DC generator in the corresponding integrated pump / turbine generator unit. and the power generation capacity of the corresponding water-based rotating generator. sum ,through The input and output voltage of the caisson energy storage bidirectional DC / DC converter Release power to the ring network ; Step 4.3.2.2 By sorting The next A submerged caisson drainage energy storage power station that regulates the DC turbine power output of the integrated pump / hydropower generator. and the power generation of the water-rotating generator And sum to ,through Submerged caisson drainage energy storage power station caisson energy storage bidirectional DC / DC converter input and output voltage Release surplus power to the ring network ; Step 4.3.2.3 By controlling the remaining quantity The corresponding underwater submerged drainage energy storage power station's water-spinning generator power generation capacity The output voltage is generated by the input and output terminals of the caisson energy storage bidirectional DC / DC converter. Power release for ring network This enables rapid suppression of power balance fluctuations between the ring network power supply and the load; among which, For the hydro-turbine DC generator at rated input power Input voltage at the input and output terminals of the caisson energy storage bidirectional DC / DC converter under the specified conditions; The number of underwater submerged caisson drainage energy storage power stations for integrated pump / hydro turbine generators under rated input and output conditions. It is an integer; The power output from the input / output terminals of the caisson energy storage bidirectional DC / DC converter for the underwater caisson drainage energy storage power station corresponding to the integrated pump / hydro turbine generator that does not participate in the operation of the rated power input / output pump; The total number of underwater submerged drainage energy storage power stations within the ring network. It is an integer; The remaining number of underwater submerged drainage energy storage power stations corresponding to water pumps / hydro turbine generators that are not operating at their rated input / output power. It is an integer; Step 4.4 includes: When the total output power of the offshore new energy DC / DC converter At that time, according to the equation (2-10) for the balance between ring network power supply and load power, we get: （4-18） Step 4.4.1 Determine the ring network power supply : According to step 1.5.3, the ring network power supply capacity is set. These are respectively equal to the total platform load DC / AC inverter input DC power The sum is obtained based on equation (4-18): （4-19） Step 4.4.2 Determine the ring network power supply voltage : The output voltage of several caisson energy storage bidirectional DC / DC converters is obtained according to equation (1-29). Equation (1-30) is used to obtain the series current of the ring network. The rated power of each unit is obtained by allocating it according to equation (2-4). Input and output voltages of a caisson energy storage bidirectional DC / DC converter under input and output conditions The remainder power is obtained from equation (2-5). Input and output voltages of caisson energy storage bidirectional DC / DC converter under certain conditions Based on equation (4-19) and the series current in the ring network. They are equal, thus the ring network power supply voltage is obtained. equal The input and output voltage of the caisson energy storage bidirectional DC / DC converter and Output voltage of the caisson energy storage bidirectional DC / DC converter Then with the remaining quantity The input and output voltage of the caisson energy storage bidirectional DC / DC converter The sum of these values ​​is equal to the total platform load DC / AC inverter DC input voltage. ,Right now: （4-20） in, for The underwater caisson drainage energy storage power station outputs a water-based rotating generator via the corresponding caisson energy storage bidirectional DC / DC converter input and output terminals, summing the power output. The corresponding output voltage; for Submerged caisson drainage energy storage power station caisson energy storage bidirectional DC / DC converter input and output rated power The product, the corresponding output voltage; or The rated output power of the submerged caisson drainage energy storage power station's integrated pump / turbine generator is... With the output power of the water-rotating generator The sum of the corresponding output voltages; for The residual power output of the bidirectional DC / DC converter for the submerged caisson drainage energy storage power station. The corresponding output voltage; Step 4.4.3 Store the remaining power generation capacity in descending order of size. Select accordingly This underwater submerged drainage energy storage power station utilizes the rated output power of the turbine-DC generator in the corresponding integrated pump / turbine generator unit. and the power generation capacity of the corresponding water-based rotating generator. sum ,through The input and output voltage of the caisson energy storage bidirectional DC / DC converter Release power to the ring network ; Step 4.4.3.1 By sorting The next A submerged caisson drainage energy storage power station that regulates the DC turbine power output of the integrated pump / hydropower generator. and the power generation of the water-rotating generator And sum to ,through Submerged caisson drainage energy storage power station caisson energy storage bidirectional DC / DC converter input and output voltage Release surplus power to the ring network ; Step 4.4.3.2 By controlling the remaining quantity The corresponding underwater submerged drainage energy storage power station's water-spinning generator power generation capacity The output voltage is generated by the input and output terminals of the caisson energy storage bidirectional DC / DC converter. Among them, voltage The remaining number of underwater caisson drainage energy storage power stations divided by the number of those corresponding to pumps / hydro turbines that are not involved in the operation of the rated power input / output pumps / hydro turbine generators. To obtain the remaining quantity The output voltage of the input and output terminals of the bidirectional DC / DC converter for each underwater caisson drainage energy storage power station. ,Right now: （4-21） Therefore, through the remaining quantity The underwater caisson drainage energy storage power station outputs voltage via the input and output terminals of the caisson energy storage bidirectional DC / DC converter. Power release for ring network This enables rapid suppression of power balance fluctuations between the ring network power supply and the load; Step 4.4.3.3 Determine the DC input voltage of the DC / AC inverter for each platform load. : The series current of the ring network obtained according to equation (1-30) And the DC input power of all platform loads DC / AC inverters within the currently collected ring network. This is how the DC input voltage of the DC / AC inverter for each platform load is allocated. ,Right now: ; Ring network series current The DC input voltage of the DC / AC inverter for each platform load is obtained through allocation. To ensure the current total output power of marine new energy DC / DC converters When it equals zero, according to equations (2-2) and (4-18), we get: （4-22） As can be seen from equation (4-22), the output power of several underwater caisson drainage energy storage power stations is obtained through the corresponding caisson energy storage bidirectional DC / DC converter input and output power terminals. sum With remaining quantity Submerged caisson drainage energy storage power station caisson energy storage bidirectional DC / DC converter input and output power The total platform load DC / AC inverter DC input power powered by.

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