Virtual energy storage balance model design method for wind-light-water storage integrated base based on cross-regional extra-high voltage direct current transmission

Abstract

The invention discloses a method for designing a virtual energy storage balance model of a wind-light-water-storage integrated base based on cross-regional extra-high voltage direct current transmission, which comprises the following steps of: constructing a regional wind-light-water-storage integrated base basic model by integrating a self-contained power generation unit and a local pumped storage power plant in a region; basic electric power and electric quantity balance constraints in the region are established; based on the regional wind-solar-water-storage integrated base basic model, configuring an integrated energy system in the region, and establishing a mathematical model for each device in the integrated energy system; the region is planned as a sending end region of the cross-region extra-high voltage direct current power transmission network; an extra-high-voltage direct-current transmission tie line is brought into a sending-end area energy storage regulation and control category, and an extra-high-voltage direct-current virtual energy storage balance model and constraint conditions are constructed. The extra-high voltage direct current virtual energy storage balance model established by the invention breaks through the traditional constant power delivery mode, can flexibly adjust the delivery power in real time according to the load demand, and realizes temporary virtual storage and on-demand calling of part of electric energy.

Description

Technical Field

[0001] This invention relates to a design method for a virtual energy storage balance model of an integrated wind-solar-hydro-storage base based on cross-regional ultra-high voltage direct current transmission, belonging to the field of new energy power generation. Background Technology

[0002] In the construction of a new power system with new energy as the main body, "West-to-East Power Transmission" is the core strategy for optimizing the cross-regional allocation of energy. The integrated "wind-solar-hydro-storage" base, as the mainstream model for clean energy development, can achieve cross-regional power transmission, but it has significant technical bottlenecks: On the one hand, the strong uncertainty of wind and solar power output and the difference in hydropower output during the wet and dry seasons can easily lead to power supply and demand mismatch, exacerbating the problem of regional power balance; on the other hand, physical energy storage has the problems of high construction costs and limited capacity, making it difficult to meet the large-scale and flexible energy storage needs of the integrated "wind-solar-hydro-storage" base.

[0003] Existing ultra-high-voltage direct current (UHVDC) transmission systems mostly employ a constant-power transmission mode, failing to fully exploit their transient transmission margin adjustment potential. Furthermore, simply converting physical energy storage into virtual energy storage can easily lead to system stability issues such as grid voltage fluctuations and frequency deviations. Therefore, how to rationally utilize the virtual energy storage potential of UHVDC transmission while controlling the cost of physical energy storage, and simultaneously relying on a regional multi-energy complementary system to ensure system stability, has become a key issue in improving the efficiency of new energy absorption and the reliability of cross-regional power supply.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] To address the power balance challenges faced by integrated wind-solar-hydro-storage bases under the "West-to-East Power Transmission" strategy, this invention provides a design method for a virtual energy storage balance model of integrated wind-solar-hydro-storage bases based on cross-regional ultra-high-voltage direct current (UHVDC) transmission. This method constructs a virtual energy storage balance model for UHVDC, providing an effective solution for the large-scale development and cross-regional optimized allocation of clean energy. Its core logic lies in breaking through the limitations of traditional physical energy storage, fully exploring the regulation potential of UHVDC transmission lines, and simultaneously relying on a multi-energy complementary system within the region to ensure system stability, thereby achieving the goals of "energy storage expansion, cost control, efficient consumption, and safe operation."

[0006] The technical solution of this invention is:

[0007] According to a first aspect of the present invention, a method for designing a virtual energy storage balance model for an integrated wind-solar-hydro-storage base under inter-regional ultra-high voltage direct current transmission is provided, comprising:

[0008] Step 1: By integrating the region's own power generation units with local pumped storage power plants, construct a basic model of the regional wind-solar-hydro-storage integrated base, and establish basic power balance constraints within the region; the basic model of the regional wind-solar-hydro-storage integrated base includes a wind power generation unit model, a photovoltaic power generation unit model, a hydropower generation unit model, and a pumped storage power plant model.

[0009] Step 2: Based on the basic model of the regional wind-solar-hydro-storage integrated base in Step 1, configure an integrated energy system within the region and establish mathematical models for each device in the integrated energy system.

[0010] Step 3: Based on Step 1 and Step 2, this region is planned as the sending-end region of the inter-regional UHVDC transmission network; the UHVDC transmission interconnection line is included in the energy storage control scope of the sending-end region, and a virtual energy storage balance model and constraints for UHVDC are constructed.

[0011] Furthermore, the basic power balance constraints within the region include:

[0012] Surplus energy storage constraint: When the total output of wind power, photovoltaic power and hydropower exceeds the real-time load demand of the region, and the power grid of the region has the capacity to absorb surplus power, the pumping mode of the pumped storage power plant is automatically triggered to convert the surplus power in the region into the gravitational potential energy of water and store it in the upper reservoir of the pumped storage power plant.

[0013] Power Shortage Compensation Constraint: When wind power and photovoltaic power generation experience a sharp drop in output due to weather factors, or when hydropower generation suffers from insufficient water supply, resulting in a power shortage in the region, the pumped storage power plant will automatically start generating power. The water stored in the upper reservoir of the pumped storage power plant will be released into the lower reservoir to drive the turbine generator unit to generate power and supplement the power gap in the region.

[0014] Furthermore, the integrated energy system includes multiple types of energy storage devices and energy conversion devices. The multiple types of energy storage devices include electricity storage devices, thermal storage devices, gas storage devices and hydrogen storage tanks. The energy conversion devices include power-to-gas devices, combined heat and power units, and gas boilers. The power-to-gas devices include electrolyzers, hydrogen fuel cells and methane reactors.

[0015] Furthermore, the ultra-high voltage direct current virtual energy storage balance model specifically includes the following:

[0016] ;

[0017] λ p + DC = ∫ ( P p ( t ) + P DC ( t ) ) d t ∫ m a x [ P p ( t ) + P DC ( t ) ] d t = E p + E DC T ⋅ m a x [ P p ( t ) + P DC ( t ) ] ;

[0018] In the formula: To maximize the absorption of renewable energy power generation; This refers to the load power. This refers to the planned external power transmission volume; the outgoing volume is positive. The average peak-shaving depth of the hydropower units within the system; The load factor is the equivalent load of "load + power transmitted through tie lines"; To account for the positive reserve capacity after new energy sources participate in the balancing process; Let be the load power at time t; The real-time outgoing power of the tie line at time t is positive; Indicates the total period.

[0019] Furthermore, the constraints include tie-line transmission constraints and virtual energy storage constraints; wherein, tie-line transmission constraints include channel capacity constraints, transmission direction constraints, output change frequency constraints, output adjustment constraints, power adjustment speed constraints, and power balance constraints.

[0020] Furthermore, the virtual energy storage constraint is:

[0021] ;

[0022] In the formula: This refers to the rated power of traditional DC power transmission methods. It is the maximum power transmitted by the nth inter-regional link at time t. Let be the real-time outgoing power of the nth inter-regional link at time t; The start and end times of power transmission for the tie line.

[0023] According to a second aspect of the present invention, a processor is provided for performing operations, the operations including the step of performing the method described in any one of the foregoing descriptions.

[0024] The beneficial effects of this invention are as follows: Considering regional differences, this invention plans and constructs this region as the sending-end area of ​​an ultra-high voltage direct current (UHVDC) transmission network. It proposes incorporating UHVDC transmission lines into the energy storage control scope, constructing a virtual energy storage operation mechanism based on the transient transmission margin and transmission time window of the transmission line. This forms an UHVDC virtual energy storage balance model, breaking the traditional fixed-power transmission mode. The transmission power can be flexibly adjusted in real time according to load demand, realizing temporary "virtual storage" and on-demand access to some electrical energy. Simultaneously, by clarifying the calculation method for the theoretical maximum renewable energy absorption capacity and multi-dimensional constraints such as channel capacity, transmission direction, and output adjustment, it prioritizes the cross-regional transmission of renewable energy generation while effectively avoiding the system stability risks that may arise from relying solely on virtual energy storage. Ultimately, without increasing the cost of physical energy storage, it indirectly expands the energy storage capacity of the integrated base, achieving an organic unity of efficient renewable energy absorption, precise cross-regional power matching, and safe and stable system operation. Attached Figure Description

[0025] Figure 1 The basic architecture diagram of the integrated "wind-solar-hydro-storage" base for configuring a comprehensive energy system.

[0026] Figure 2 This is a diagram of the internal framework of an integrated energy system.

[0027] Figure 3 This is a schematic diagram of the load response.

[0028] Figure 4 This is a schematic diagram of virtual energy storage for ultra-high voltage direct current transmission.

[0029] Figure 5 This is a flowchart of the present invention. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other.

[0031] Example 1: As Figures 1-5 As shown, according to a first aspect of the present invention, a method for designing a virtual energy storage balance model for an integrated wind-solar-hydro-storage base under cross-regional ultra-high voltage direct current transmission is provided, comprising the following steps:

[0032] Step 1: By integrating the region's own power generation units with local pumped storage power plants, construct a basic model of the regional wind-solar-hydro-storage integrated base, and establish basic power balance constraints within the region; the basic model of the regional wind-solar-hydro-storage integrated base includes a wind power generation unit model, a photovoltaic power generation unit model, a hydropower generation unit model, and a pumped storage power plant model.

[0033] like Figure 1 As shown, by integrating the region's own power generation units with local pumped storage power plants, an energy supply system with basic "power generation-energy storage" linkage capabilities is formed. This enables the establishment of a basic model for the integrated wind, solar, hydro, and storage base in the region, providing underlying energy and energy storage support for subsequent overall power balance regulation. Specifically, this includes:

[0034] I. Power Generation Unit Model

[0035] 1. Wind power generation unit model:

[0036] Based on the wind energy resource assessment report for this region, areas with an annual average wind speed of not less than 6 m / s and wind power density that meets the requirements for grid connection were selected as wind farm sites. Wind turbine generators adapted to the wind conditions of this region were configured. The mathematical model is as follows:

[0037] ;

[0038] ;

[0039] In the formula, It is the output electrical power of the wind turbine generator set; This is the maximum output electrical power of the wind turbine generator set; This is the rated output power of the wind turbine generator set; This is the actual wind speed in the current environment; It is the cut-in wind speed of the wind power generation equipment; It is the cut-out wind speed of the wind power generation equipment; This refers to the rated operating wind speed of wind power generation equipment.

[0040] 2. Photovoltaic power generation unit model:

[0041] Based on data such as regional solar irradiance and sunshine duration, photovoltaic power generation arrays are deployed in areas with abundant solar resources and suitable land use conditions. Inverters are then configured to achieve DC-AC conversion and grid connection of the photovoltaic power generation units. The mathematical model is as follows:

[0042] P P V = ( Y P V ( R T R S T C ) [ 1 + η ( T C + T S T C ) ] ) × ( 1 − γ ) ;

[0043] ;

[0044] In the formula: This refers to the actual output power of the photovoltaic cell; , These are the minimum and maximum output power of the photovoltaic cell; This refers to the rated output power of the photovoltaic cell; This represents the actual intensity of solar radiation. Light intensity under standard test conditions; Temperature coefficient of photovoltaic modules; This refers to the actual temperature of the photovoltaic module. Temperature measured under standard conditions; This represents the shading coefficient of the photovoltaic array.

[0045] 3. Hydropower Unit Model:

[0046] For river basins within the region with suitable development conditions, hydroelectric power stations of appropriate scale should be constructed. These hydroelectric power generation units need to be connected to the regional power grid via step-up transformers to achieve grid-connected coordination with other power generation units. In the process of hydroelectric power generation, where potential energy is converted into mechanical energy and then into electrical energy, the output of the hydroelectric power station, after accounting for losses, is simplified in practical calculations as follows:

[0047] ;

[0048] In the formula: Let t be the output power of the hydroelectric power station during time period t; This is the output coefficient of a hydroelectric power station; it is generally taken as [value missing] for small hydroelectric power stations. Large and medium-sized hydropower stations ; The velocity of the water flow; This refers to the head height of the water turbine.

[0049] The power output constraints and reservoir capacity constraints for hydropower generation are as follows:

[0050] ;

[0051] ;

[0052] in, , These are the maximum and minimum output power, respectively. Indicates the time of power generation. This refers to the reservoir's storage capacity.

[0053] II. Pumped Storage Power Plant Model

[0054] Pumped-storage power plants have two operating modes. When electricity demand is low, they absorb excess electricity to transport water from the lower reservoir to the upper reservoir, thus storing energy. When the power system's load is high, the pumped-storage power station releases water from the upper reservoir to drive turbines and generate electricity. Due to the physical limitations of pumped-storage power plants, these two modes cannot be performed simultaneously. The mathematical formula is:

[0055] The power output of the pumped storage power plant is:

[0056] ;

[0057] The pumping capacity of the pumped storage power plant is:

[0058] ;

[0059] The change in the upper reservoir capacity of the pumped storage power station is as follows:

[0060] ;

[0061] In the formula: Let t be the output power of the pumped storage power plant turbine; The power generation coefficient; The water consumption for power generation during period t; Let t be the pumping volume of the pumped storage power station at time t; Pumping coefficient of a hydroelectric power station; The amount of electricity used for pumping water during time period t.

[0062] III. Regional Basic Electricity Balance Constraints

[0063] Surplus energy storage constraint: When the total output of wind power, photovoltaic power, and hydropower exceeds the real-time load demand of the region, and the regional power grid has the capacity to absorb surplus electricity, the pumped storage power plant is automatically triggered to pump out the surplus electricity in the region and store it in the upper reservoir of the pumped storage power plant by converting the surplus electricity in the region into the gravitational potential energy of water. At this time, the pumped storage power plant acts as a load-side device to absorb the surplus electricity.

[0064] Power Shortage Compensation Constraint: When wind power and photovoltaic power generation experience a sudden drop in output due to weather factors, or when hydropower generation suffers from insufficient water supply, resulting in a power shortage in the region, the pumped storage power plant is automatically triggered to operate in power generation mode. The water stored in the upper reservoir of the pumped storage power plant is released into the lower reservoir to drive the turbine generator unit to generate electricity and supplement the power gap in the region. At this time, the pumped storage power plant participates in power supply as a power source.

[0065] Step 2: Based on the basic model of the regional wind-solar-hydro-storage integrated base in Step 1, configure an integrated energy system within the region to form a diversified energy storage and consumption system; the integrated energy system includes multiple types of energy storage equipment and energy conversion devices.

[0066] As attached Figure 2 As shown, the core objective of this step is to configure an integrated energy system based on the basic model built in step 1, construct a multi-level and multi-dimensional energy storage and consumption system, solve the problem of consuming surplus electricity in the region, and realize flexible allocation of cross-regional electricity.

[0067] An integrated energy system is configured within this region, interconnected with the power generation units via a large power grid. The integrated energy system includes various types of energy storage devices and energy conversion devices. The various types of energy storage devices include electricity storage devices, thermal storage devices, gas storage devices, and hydrogen storage tanks. The energy conversion devices include power-to-gas devices, combined heat and power units, and gas boilers. The power-to-gas devices include electrolyzers, hydrogen fuel cells, and methane reactors. Through the integrated energy system, multiple energy storage devices such as heat, electricity, gas, and hydrogen can achieve multi-energy coupling, conversion, storage, and utilization, enabling mutual conversion between different forms of energy and enhancing the flexibility of system output.

[0068] The mathematical model of the electro-gas conversion device is constructed as follows:

[0069] 1. Electrolytic cell model

[0070] There is a certain relationship between the hydrogen production capacity of an electrolyzer and its input electrical power and operating efficiency. Assuming the electrolyzer operates at a constant point, the amount of hydrogen produced is proportional to the electrical energy consumed. The mathematical model of the electrolyzer's operating characteristics can be described as follows:

[0071] ;

[0072] In the formula: The electrical power input to the electrolytic cell; The amount of hydrogen produced by the electrolyzer; This refers to the operating efficiency coefficient of the electrolytic cell; and These are the upper and lower limits of the electrical power input to the electrolytic cell, respectively. and These represent the upper and lower limits of the ramp power of the electrolytic cell.

[0073] 2. Methane reactor model

[0074] The gas production capacity of a methane reactor is generally considered to be related to the amount of gas produced and the gas production efficiency of the reactor. The mathematical model for the operation of a methane reactor is as follows:

[0075] ;

[0076] In the formula: This indicates the amount of natural gas output from the methane reactor MR. This indicates the amount of hydrogen input to the methane reactor. The efficiency of hydrogen-to-natural gas conversion in a methane reactor; , These are the upper and lower limits of the output power of the methane reactor; , Adjust the upper and lower limits of the output of the methane reactor.

[0077] 3. Hydrogen fuel cell model

[0078] Hydrogen fuel cells primarily rely on an exothermic redox reaction between hydrogen and oxygen to achieve energy conversion. A heat exchange device can be used to recover and utilize the waste heat generated during the reaction, thus achieving a synergistic output of electrical and thermal energy. Based on the above technical principles, its mathematical model is as follows:

[0079] ;

[0080] In the formula: The hydrogen energy input into the hydrogen fuel cell (HFC) during time period t; Let t be the electrical power output by the HFC during time period t; The thermal power output of the HFC during time period t; , These are the efficiency coefficients for converting HFC into electrical and thermal energy, respectively. , These are the upper and lower limits of the capacity for HFC to input hydrogen energy, respectively; , These are the upper and lower limits for HFC power adjustment; , These are the upper and lower limits of the thermoelectric ratio of HFC, respectively.

[0081] The model of a combined heat and power (CHP) unit is as follows:

[0082] The key consideration is the intrinsic relationship between its power generation, heat generation, power generation efficiency, heat generation efficiency, and fuel consumption. The corresponding specific mathematical model expression is as follows:

[0083] ;

[0084] In the formula: , These represent the efficiency coefficients of the CHP unit in achieving electrical and thermal conversion, respectively. The amount of natural gas input to the combined heat and power unit during time period t; This represents the electrical power output by CHP at time t; The heat energy output by CHP during time period t; It characterizes the thermoelectric power ratio of CHP; , These are the upper and lower limits for the amount of natural gas input into CHP, respectively. , These represent the upper and lower limits of the CHP ramp rate, respectively. , These represent the upper and lower limits of the thermoelectric power ratio of CHP, respectively.

[0085] The gas-fired boiler model is as follows:

[0086] Gas-fired boilers can promptly supplement heat energy when the overall energy system's heat load is insufficient, thereby optimizing the overall system operation and improving overall energy utilization efficiency. Therefore, the mathematical model for a gas-fired boiler is as follows:

[0087] ;

[0088] In the formula: The heat energy output by GB during time period t; Conversion efficiency for GB; The amount of natural gas input to the gas-fired boiler during time period t; , These represent the upper and lower limits of capacity in GB; , These are the upper and lower limits for power adjustment in GB, respectively.

[0089] The energy storage device model is as follows:

[0090] Since energy storage devices of various types have similar mathematical models, a general model is used to solve the problem of energy storage devices:

[0091] ;

[0092] In the formula: , The charging and discharging power of the energy storage device during time period t. , This represents the upper limit of the charging and discharging power of the energy storage device during time period t; This represents the initial energy stored in the energy storage device. The energy stored in the energy storage device during time period t; , This serves as a marker for the charging and discharging status of the energy storage device during time period t. , These are the lower and upper limits of the energy storage capacity of the energy storage device; , The energy storage and release efficiency of energy storage devices; The rated energy storage capacity of the energy storage device; These correspond to energy storage devices, heat storage devices, gas storage devices, and hydrogen storage tanks, respectively.

[0093] like Figure 3 As shown, during normal operation, for scenarios with small load fluctuations within the power system, the various types of energy storage devices and energy conversion devices configured in step 2 are prioritized for activation. Utilizing their fast response speed and high control precision, load fluctuations are quickly mitigated, while surplus electricity is absorbed in multiple forms, reducing frequent calls to pumped-storage power plants and ensuring the stable operation of the basic energy model. When the integrated base in this region functions as a "West-to-East Power Transmission" hub, the control logic switches to a cross-regional power transmission priority mode. At this time, the pumped-storage power plant integrated in step 1 serves as the core energy storage and regulation unit. Leveraging its large capacity and long-cycle energy storage characteristics, it undertakes the valley-filling demand for cross-regional power transmission. Simultaneously, in conjunction with the virtual energy storage function of ultra-high-voltage direct current transmission, the overall regional power transmission and regulation capacity is further expanded, ensuring precise matching between the transmission scale and the electricity demand of the eastern load center, achieving efficient synergy between regional energy storage resources and the cross-regional power transmission system.

[0094] Step 3: Based on Step 1 and Step 2, this region is planned as the sending-end region of the inter-regional UHVDC transmission network, and a key link for the West-to-East Power Transmission is established; the UHVDC transmission interconnection line is included in the energy storage regulation scope of the sending-end region, and a virtual energy storage balance model and constraints for UHVDC are constructed.

[0095] Based on the regional integrated wind-solar-hydro-storage base model established in Step 1 and the internal multi-element energy storage and consumption system built in Step 2, this region will be planned and constructed as the sending-end area of ​​a cross-regional ultra-high-voltage direct current (UHVDC) transmission network. A dedicated transmission link will be established to open up the core transfer channel for "West-to-East Power Transmission," enabling the targeted transmission of electricity to load centers in the east. A virtual energy storage balance model for UHVDC will be constructed, utilizing the "virtual energy storage" characteristics of the UHVDC transmission channel to flexibly adjust the global power supply and demand between regions.

[0096] The ultra-high voltage direct current virtual energy storage balance model specifically includes the following:

[0097] ;

[0098] λ p + DC = ∫ ( P p ( t ) + P DC ( t ) ) d t ∫ m a x [ P p ( t ) + P DC ( t ) ] d t = E p + E DC T ⋅ m a x [ P p ( t ) + P DC ( t ) ] ;

[0099] In the formula: To maximize the absorption of renewable energy power generation; This refers to the load power. This refers to the planned external power transmission volume; the outgoing volume is positive. The average peak-shaving depth of the hydropower units within the system; The load factor is the equivalent load of "load + power transmitted through tie lines"; To account for the positive reserve capacity after new energy sources participate in the balancing process.

[0100] When this region acts as a power-transmitting area, transmitting electricity to other regions, the maximum renewable energy generation capacity that the power system can absorb at time t is... for:

[0101] ;

[0102] In the formula: Let be the load power at time t; The real-time outgoing power of the tie line at time t is positive; Let i be the minimum output of the i-th hydropower unit in the system; This represents the total number of all hydropower units in the system.

[0103] The power transmitted through the tie line must meet the channel capacity constraints:

[0104] ;

[0105] In the formula , These are the minimum and maximum values ​​of the power transmitted by the tie line at time t.

[0106] The constraints include tie-line transmission constraints and virtual energy storage constraints.

[0107] The communication line transmission constraints are as follows:

[0108] (1) Channel capacity constraints

[0109] ;

[0110] In the formula, , These are the minimum and maximum values ​​of the power transmitted by the nth inter-regional link at time t. For the nth connection line .

[0111] (2) Transmission direction constraints

[0112] Ultra-high voltage direct current (UHVDC) transmission is unidirectional, and no power adjustment in opposite directions is allowed during the transmission process; that is, the transmission power must maintain the same signal.

[0113] ;

[0114] In the formula, 0 and 1 represent different transmission directions. This indicates the sign of the transmitted power.

[0115] (3) Constraint on the number of times output changes

[0116] ;

[0117] In the formula: This represents the number of power output adjustments made by the nth connection line within one cycle. Indicates the total number of connecting lines; This represents the total number of adjustments within period T.

[0118] (4) Output adjustment constraint

[0119] Ultra-high voltage direct current transmission cannot change instantaneously; that is, after the output is adjusted once, it needs to operate smoothly for at least a minimum duration. Therefore, the constraint that needs to be met is:

[0120] ;

[0121] In the formula: This indicates whether the DC transmission tie line is adjusted at time t. It is a 0-1 variable, where 0 indicates that the output of the tie line has not changed and 1 indicates that the output has changed.

[0122] (5) Power adjustment speed

[0123] ;

[0124] ;

[0125] In the formula: , For the minimum and maximum speed of the output adjustment on the nth connecting line, Indicates the same sign for the transmitted power. This represents the condition when the value is greater than t and closest to t. , This represents the value less than t and closest to t. .

[0126] (6) Power balance constraint

[0127] ;

[0128] In the formula: This represents the total power on the connection line.

[0129] (7) Power balance constraints

[0130] ;

[0131] middle: Let n be the transmission power of tie line n at time t; N is the total number of tie lines. This represents the received power at the receiving end.

[0132] refer to Figure 4 The virtual energy storage constraint is:

[0133] ;

[0134] In the formula: This refers to the rated power of traditional DC power transmission methods. It is the maximum power transmitted by the nth inter-regional link at time t. The real-time outgoing power of the nth inter-regional link at time t (i.e. Figure 4 (Power transmitted under virtual energy storage effect).

[0135] As can be seen from the above technical solution, in terms of technical architecture, this invention constructs a balanced system from regional energy supply to cross-regional power transmission. Firstly, taking regional renewable energy sources such as wind and solar power as the core, it integrates wind power generation units, photovoltaic power generation units, hydropower generation units, etc., and integrates local pumped storage power plants to form a basic model with "power generation-energy storage" linkage capabilities. By clarifying the adaptation conditions and mathematical models of each power generation unit, a stable and reliable underlying energy support is provided for the system. Simultaneously, by utilizing the charging and discharging switching logic of the pumped storage power plant, the dynamic adjustment of regional power surplus and deficit is initially realized.

[0136] Building upon this foundation, the region's energy utilization efficiency has been further optimized, constructing a closed-loop, multi-dimensional energy storage and consumption system. By configuring various types of energy storage devices, including electricity, heat, gas, and hydrogen storage, as well as energy conversion devices such as electrolyzers, hydrogen fuel cells, combined heat and power units, and gas-fired boilers, a multi-energy coupled control network of "electricity-heat-gas-hydrogen" is formed. This not only enables the mutual conversion and flexible use of different forms of energy but also allows for rapid response to minor load fluctuations within the region, efficiently absorbing surplus electricity. During normal operation, leveraging the fast response speed and high control precision of the diverse energy storage and energy conversion devices, load fluctuations can be mitigated, reducing the frequent use of pumped storage power plants. In cross-regional power transmission scenarios, the large-capacity energy storage characteristics of pumped storage power plants can accommodate load demands, forming a tiered and differentiated control mode.

[0137] Furthermore, this region is planned and constructed as the sending-end area of ​​an ultra-high voltage direct current (UHVDC) transmission network. It proposes incorporating UHVDC transmission lines into the energy storage control framework, constructing a virtual energy storage operation mechanism based on the transient transmission margin and transmission time window of the transmission lines. This forms an UHVDC virtual energy storage balance model, breaking the traditional fixed-power transmission mode. The transmitted power can be flexibly adjusted in real time according to load demand, achieving temporary "virtual storage" and on-demand access to some electrical energy. Simultaneously, by clarifying the calculation method for the theoretical maximum renewable energy absorption capacity and multi-dimensional constraints such as channel capacity, transmission direction, and output adjustment, it prioritizes the cross-regional transmission of renewable energy while effectively avoiding the system stability risks that may arise from relying solely on virtual energy storage. Ultimately, without increasing the cost of physical energy storage, it indirectly expands the energy storage capacity of the integrated base, achieving an organic unity of efficient renewable energy absorption, precise cross-regional power matching, and safe and stable system operation.

[0138] According to a second aspect of the present invention, a processor is provided for performing operations, the operations including the step of performing the method described in any one of the foregoing embodiments.

[0139] The specific embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A design method for a virtual energy storage balance model of an integrated wind-solar-hydro-storage base based on cross-regional ultra-high voltage direct current transmission, characterized in that, include: Step 1: By integrating the region's own power generation units with local pumped storage power plants, construct a basic model of the regional wind-solar-hydro-storage integrated base, and establish basic power balance constraints within the region; the basic model of the regional wind-solar-hydro-storage integrated base includes a wind power generation unit model, a photovoltaic power generation unit model, a hydropower generation unit model, and a pumped storage power plant model; Step 2: Based on the basic model of the regional wind-solar-hydro-storage integrated base in Step 1, configure an integrated energy system within the region and establish mathematical models for each device in the integrated energy system. Step 3: Based on Step 1 and Step 2, this region is planned as the sending-end region of the inter-regional UHVDC transmission network; the UHVDC transmission interconnection line is included in the energy storage control scope of the sending-end region, and a virtual energy storage balance model and constraints for UHVDC are constructed.

2. The design method for a virtual energy storage balance model of an integrated wind-solar-hydro-storage base based on cross-regional ultra-high voltage direct current transmission as described in claim 1, is characterized in that... The basic power balance constraints within the region include: Surplus energy storage constraint: When the total output of wind power, photovoltaic power and hydropower exceeds the real-time load demand of the region, and the power grid of the region has the capacity to absorb surplus power, the pumping mode of the pumped storage power plant is automatically triggered to convert the surplus power in the region into the gravitational potential energy of water and store it in the upper reservoir of the pumped storage power plant. Power Shortage Compensation Constraint: When wind power and photovoltaic power generation experience a sharp drop in output due to weather factors, or when hydropower generation suffers from insufficient water supply, resulting in a power shortage in the region, the pumped storage power plant will automatically start generating power. The water stored in the upper reservoir of the pumped storage power plant will be released into the lower reservoir to drive the turbine generator unit to generate power and supplement the power gap in the region.

3. The design method for a virtual energy storage balance model of an integrated wind-solar-hydro-storage base based on cross-regional ultra-high voltage direct current transmission as described in claim 1, is characterized in that... The integrated energy system includes multiple types of energy storage devices and energy conversion devices. The multiple types of energy storage devices include electricity storage devices, thermal storage devices, gas storage devices and hydrogen storage tanks. The energy conversion devices include power-to-gas devices, combined heat and power units, and gas boilers. The power-to-gas devices include electrolyzers, hydrogen fuel cells and methane reactors.

4. The design method for a virtual energy storage balance model of an integrated wind-solar-hydro-storage base based on cross-regional ultra-high voltage direct current transmission as described in claim 1, is characterized in that... The ultra-high voltage direct current virtual energy storage balance model specifically includes the following: ； ； In the formula: To maximize the absorption of renewable energy power generation; This refers to the load power. This refers to the planned external power transmission volume; the outgoing volume is positive. The average peak-shaving depth of the hydropower units within the system; The load factor is the equivalent load of "load + power transmitted through tie lines"; To account for the positive reserve capacity after new energy sources participate in the balancing process; Let be the load power at time t; The real-time outgoing power of the tie line at time t is positive; Indicates the total period.

5. The design method for a virtual energy storage balance model of an integrated wind-solar-hydro-storage base based on cross-regional ultra-high voltage direct current transmission as described in claim 1, characterized in that, The constraints include tie-line transmission constraints and virtual energy storage constraints; among which, tie-line transmission constraints include channel capacity constraints, transmission direction constraints, output change frequency constraints, output adjustment constraints, power adjustment speed constraints, and power balance constraints.

6. The design method for a virtual energy storage balance model of an integrated wind-solar-hydro-storage base based on cross-regional ultra-high voltage direct current transmission as described in claim 5, is characterized in that... The virtual energy storage constraint is: ； In the formula: This refers to the rated power of traditional DC power transmission methods. It is the maximum power transmitted by the nth inter-regional link at time t. Let be the real-time outgoing power of the nth inter-regional link at time t; The start and end times of power transmission for the tie line.

7. A processor, characterized in that, The processor is used to perform operations, which include the steps of performing any of the methods described above.

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