New energy off-grid operation system and method

Abstract

The invention discloses a new energy off-grid operation system and method. The new energy off-grid operation system comprises a large-capacity energy storage system branch, an active / passive filtering system branch, a water electrolysis hydrogen production system branch, a station power system branch and a plurality of new energy alternating current system branches which are respectively connected with a medium-voltage alternating current bus; the plurality of new energy alternating current system branches inject electric energy generated by new energy power generation into a power grid through a medium-voltage alternating current bus, and the new energy alternating current system branches adjust power generation power according to load conditions; each system branch performs energy transmission through a medium-voltage alternating-current bus; the water electrolysis hydrogen production system decomposes water into hydrogen and oxygen through electric energy generated by new energy power generation, and the water electrolysis hydrogen production system adjusts the hydrogen production power by being connected with a medium-voltage alternating-current bus. An active filtering system of the active / passive filtering system branch compensates harmonic waves and reactive power in the power grid, and a passive filtering system filters the harmonic waves; and the station power utilization system provides power for the new energy off-grid operation system.

Description

Technical Field

[0001] The present invention belongs to the technical field of off-grid operation of new energy, and specifically relates to a system and method for off-grid operation of new energy. Background Art

[0002] In recent years, the application of new energy technologies and related products has achieved great development. However, due to the uneven distribution of new energy resources, a large number of new energy resources are located in sparsely populated areas, which are often mountainous areas or plateaus. The power grid has not yet radiated to many places, and the construction cost is very high, which has created difficulties for the development and utilization of new energy resources in a short period of time. In order to bypass the grid connection problem, experts in the power industry have proposed a technical solution for the off-grid development of new energy resources. The basic idea is to establish an off-grid new energy base in areas rich in new energy resources, and develop high-energy-consuming products to consume new energy power generation on the spot. The advancement of equipment manufacturing technology now provides technical support for the off-grid operation of new energy power generation systems.

[0003] There are many new energy off-grid operation schemes proposed, including AC and DC schemes, but due to low technical maturity, high cost and low reliability, there are no large-capacity operation examples. The commonly used scheme is that photovoltaic power generation is gathered through the DC bus and then transmitted to the hydrogen production system in the form of DC transmission, and the hydrogen production power source is stepped down by a DC / DC converter. However, the scheme in which photovoltaic power is gathered through DC and then transmitted to the hydrogen production power source in DC mode requires a large number of power electronic devices to perform step-up and step-down conversions, and fault removal requires DC current interrupting equipment, which also requires a large number of power electronic devices. These devices often require high-power and complex auxiliary cooling systems, low transmission and transformation efficiency, complex maintenance, high cost and low reliability. Summary of the invention

[0004] The purpose of the present invention is to overcome the problem of high cost of off-grid operation of new energy AC, and propose a new energy off-grid operation system and method.

[0005] In order to achieve the above object, the present invention adopts the following technical scheme: A new energy off-grid operation system, comprising a large-capacity energy storage system branch, an active / passive filtering system branch, a water electrolysis hydrogen production system branch, a station power system branch and a plurality of new energy AC system branches; the large-capacity energy storage system branch, the active / passive filtering system branch, the water electrolysis hydrogen production system branch, the station power system branch and the plurality of new energy AC system branches are respectively connected to a medium-voltage AC busbar; Several new energy AC system branches inject the electric energy generated by new energy power generation into the power grid through the medium-voltage AC bus. The new energy AC system branches adjust the power generation according to the load conditions. Each system branch transmits energy through the medium-voltage AC bus. The water electrolysis hydrogen production system uses the electric energy generated by new energy power generation to decompose water into hydrogen and oxygen. The water electrolysis hydrogen production system adjusts the hydrogen production power by connecting to the medium-voltage AC bus. The active filter system of the active / passive filter system branch compensates for the harmonics and reactive power in the power grid, and the passive filter system filters out the harmonics. The station power system provides power for the new energy off-grid operation system.

[0006] Further, the several new energy AC system branches include a photovoltaic AC branch and a wind power AC branch, the photovoltaic AC branch includes a photovoltaic AC switch unit, a photovoltaic AC transformer unit and a photovoltaic battery array, one end of the photovoltaic AC switch unit is connected to the medium voltage AC bus, the other end of the photovoltaic AC switch unit is connected to one end of the photovoltaic AC transformer unit, and the other end of the photovoltaic AC transformer unit is connected to the photovoltaic battery array; The photovoltaic AC switch unit includes a photovoltaic AC isolation switch, a photovoltaic AC first grounding switch, a photovoltaic AC circuit breaker and a photovoltaic AC second grounding switch; The photovoltaic AC transformation unit includes a photovoltaic AC step-up and step-down transformer and a photovoltaic AC third grounding switch; The photovoltaic cell array includes a plurality of photovoltaic cell groups, and the photovoltaic cell groups include a photovoltaic inverter, a photovoltaic cell low-voltage circuit breaker and a photovoltaic cell grounding switch; One end of the photovoltaic AC isolation switch is connected to the medium voltage AC busbar, the other end of the photovoltaic AC isolation switch is connected to one end of the photovoltaic AC circuit breaker, the photovoltaic AC first grounding switch is connected between the photovoltaic AC isolation switch and the photovoltaic AC circuit breaker, the other end of the photovoltaic AC circuit breaker is connected to one end of the photovoltaic AC step-up and step-down transformer, and the photovoltaic AC second grounding switch is connected between the photovoltaic AC circuit breaker and the photovoltaic AC step-up and step-down transformer; The other end of the photovoltaic AC step-up / step-down transformer is connected to one end of the photovoltaic cell low-voltage circuit breaker, and the photovoltaic AC third grounding switch is connected between the photovoltaic AC step-up / step-down transformer and the photovoltaic cell low-voltage circuit breaker; The other end of the photovoltaic cell low-voltage circuit breaker is connected to the photovoltaic inverter, and the photovoltaic cell grounding switch is connected between the photovoltaic inverter and the photovoltaic cell low-voltage circuit breaker; The voltage of the medium voltage AC bus is 6 kV to 35 kV, and the operating frequency is 75 Hz to 200 Hz.

[0007] Furthermore, the large-capacity energy storage system branch includes a large-capacity energy storage system switch unit, an energy storage converter and an energy storage battery, one end of the large-capacity energy storage system switch unit is connected to the medium-voltage AC bus, and the other end of the large-capacity energy storage system switch unit is connected to the energy storage converter and the energy storage battery; The large-capacity energy storage system switch unit includes a large-capacity energy storage system isolation switch, a large-capacity energy storage system first grounding switch, a large-capacity energy storage system AC circuit breaker and a large-capacity energy storage system second grounding switch; One end of the large-capacity energy storage system isolation switch is connected to the medium-voltage AC busbar, the other end of the large-capacity energy storage system isolation switch is connected to one end of the large-capacity energy storage system AC circuit breaker, the first grounding switch of the large-capacity energy storage system is connected between the large-capacity energy storage system isolation switch and the large-capacity energy storage system AC circuit breaker, the other end of the large-capacity energy storage system AC circuit breaker is connected to the energy storage inverter and the energy storage battery, and the second grounding switch of the large-capacity energy storage system is connected between the large-capacity energy storage system AC circuit breaker and the energy storage inverter and the energy storage battery.

[0008] Further, the active / passive filtering system branch includes an active / passive filtering system switch unit, an APF converter and an inductor and capacitor, one end of the active / passive filtering system switch unit is connected to the medium voltage AC bus, and the other end of the active / passive filtering system switch unit is connected to the APF converter and the inductor and capacitor; The active / passive filtering system switch unit includes an active / passive filtering system isolation switch, an active / passive filtering system first grounding switch, an active / passive filtering system AC circuit breaker and an active / passive filtering system second grounding switch; One end of the active / passive filtering system isolation switch is connected to the medium voltage AC bus, the other end of the active / passive filtering system isolation switch is connected to one end of the active / passive filtering system AC circuit breaker, the first grounding switch of the active / passive filtering system is connected between the active / passive filtering system isolation switch and the active / passive filtering system AC circuit breaker, the other end of the active / passive filtering system AC circuit breaker is connected to the APF converter and the inductor and capacitor, and the second grounding switch of the active / passive filtering system is connected between the active / passive filtering system AC circuit breaker and the APF converter and the inductor and capacitor.

[0009] Further, the branch of the water electrolysis hydrogen production system includes a 12N pulsating water electrolysis hydrogen production system, and the 12N pulsating water electrolysis hydrogen production system includes a 12N pulsating water electrolysis hydrogen production system switch unit, a 12N pulsating hydrogen production power supply, an electrolyzer and a hydrogen storage system; one end of the 12N pulsating water electrolysis hydrogen production system switch unit is connected to a medium-voltage AC bus, the other end of the 12N pulsating water electrolysis hydrogen production system switch unit is connected to one end of the 12N pulsating hydrogen production power supply, the other end of the 12N pulsating hydrogen production power supply is connected to one end of the electrolyzer, and the other end of the electrolyzer is connected to the hydrogen storage system; The 12N pulsating water electrolysis hydrogen production system switch unit includes a 12N pulsating water electrolysis hydrogen production system isolation switch, a 12N pulsating water electrolysis hydrogen production system first grounding switch, a 12N pulsating water electrolysis hydrogen production system AC circuit breaker and a 12N pulsating water electrolysis hydrogen production system second grounding switch; One end of the 12N pulsating water electrolysis hydrogen production system isolation switch is connected to the medium-voltage AC bus, the other end of the 12N pulsating water electrolysis hydrogen production system isolation switch is connected to one end of the 12N pulsating water electrolysis hydrogen production system AC circuit breaker, the 12N pulsating water electrolysis hydrogen production system first grounding switch is connected between the 12N pulsating water electrolysis hydrogen production system isolation switch and the 12N pulsating water electrolysis hydrogen production system AC circuit breaker, the other end of the 12N pulsating water electrolysis hydrogen production system AC circuit breaker is connected to one end of the 12N pulsating hydrogen production power supply, and the 12N pulsating water electrolysis hydrogen production system second grounding switch is connected between the 12N pulsating water electrolysis hydrogen production system AC circuit breaker and the 12N pulsating hydrogen production power supply.

[0010] Furthermore, the station power system branch includes a station power system switch unit, a station power system transformer unit, a UPS system and a diesel generator system; one end of the station power system switch unit is connected to the medium voltage AC bus, the other end of the station power system switch unit is connected to one end of the station power system transformer unit, and the other end of the station power system transformer unit is connected to the UPS system and the diesel generator system; The station power system switch unit includes a station power system isolation switch, a station power system first grounding switch, a station power system AC circuit breaker and a station power system second grounding switch; The station power system transformer unit includes a station power system step-up and step-down transformer and a station power system third grounding switch; One end of the station power system isolation switch is connected to the medium voltage AC busbar, the other end of the station power system isolation switch is connected to one end of the station power system AC circuit breaker, the station power system first grounding switch is connected between the station power system isolation switch and the station power system AC circuit breaker, the other end of the station power system AC circuit breaker is connected to one end of the station power system step-up and step-down transformer, and the station power system second grounding switch is connected between the station power system AC circuit breaker and the station power system step-up and step-down transformer; The other end of the step-up and step-down transformer of the station power system is connected to the UPS system and the diesel generator system, and the third grounding switch of the station power system is connected between the step-up and step-down transformer of the station power system and the UPS system and the diesel generator system.

[0011] A method for operating a new energy off-grid operation system, using the new energy off-grid operation system, comprises the following steps: When the predicted value of renewable energy power generation is greater than the starting power, the renewable energy off-grid operation system enters the operating state according to the starting procedure, and carries out renewable energy power generation and hydrogen production; when the renewable energy power generation and the predicted value of renewable energy power generation are both less than the starting power, and the system is not in the full charge and discharge test of the energy storage system, the renewable energy off-grid operation system stops operating according to the shutdown procedure, and only the station power system retains the minimum control system operation.

[0012] Furthermore, the startup procedure comprises the following steps: The power system of the control station of the minimum control system is started to supply power to the control equipment of the entire station; After the station power system is operating normally, start all secondary control systems and check the health status of primary equipment; If the number of healthy primary devices meets the startup requirements and the renewable energy power generation is greater than the allowed startup power threshold, the primary devices will be officially started; Start the large-capacity energy storage system, active / passive filtering system, new energy power generation system and water electrolysis hydrogen production system in sequence. If the equipment fails to start during the startup process, the startup is terminated and the system startup failure information is transmitted. Otherwise, the system startup success information is transmitted. The shutdown procedure includes the following steps: Shut down the hydrogen production system, shut down the new energy power generation system, shut down the active / passive filtering system, shut down the large-capacity energy storage system, shut down the secondary control system of the primary equipment, and only keep the minimum control system working.

[0013] A method for controlling hydrogen production of a new energy off-grid operation system, using the new energy off-grid operation system, includes: when the maximum available capacity of the hydrogen production load is greater than or equal to the predicted power of the new energy power generation, the photovoltaic of the new energy AC system generates electricity at the maximum predicted power, and the control strategy of the hydrogen production load power is specifically as follows: According to the battery power status of the large-capacity energy storage system, after adjusting the charging and discharging mode of the energy storage battery, the charging and discharging power of the energy storage battery is calculated according to the charging and discharging power calculation formula of the energy storage battery with different charging and discharging modes; The hydrogen production load power is calculated according to the first calculation formula of the hydrogen production load power using the charging and discharging power of the energy storage battery. When the hydrogen production load power is less than the start threshold, the hydrogen production power supply is locked until the hydrogen production load power is greater than the start threshold; The first calculation formula of the hydrogen production load power is as follows: P_Load =min(P_Load_Max,max(0,P_solar_Max+P_PcsChg)) Among them, P_Load is the hydrogen production load power, P_Load_Max is the maximum available capacity of the hydrogen production load, P_solar_Max is the predicted power of new energy power generation, and P_PcsChg is the expected charging power of the energy storage system; When the maximum available capacity of hydrogen production load is less than the predicted power of new energy power generation, the specific strategy of hydrogen production load and photovoltaic power generation is as follows: According to the battery power state of the large-capacity energy storage system, the charging and discharging mode of the energy storage battery is determined, and the charging and discharging power of the energy storage battery is calculated according to the charging and discharging mode of the energy storage battery; The new energy power generation power is calculated according to the new energy power generation power adjustment formula using the energy storage battery charging and discharging power, and the hydrogen production load power is calculated according to the new energy power generation power and the second calculation formula of the hydrogen production load power. When the hydrogen production load power is less than the start threshold, the hydrogen production power supply is locked until the hydrogen production load power is greater than the start threshold; The new energy power generation power adjustment formula is as follows: P_solar =min(P_solar_Max,max(0,P_Load_Max-P_PcsChg)) Among them, P_solar is the power generated by new energy, P_solar_Max is the predicted power generated by new energy, P_Load_Max is the maximum available capacity of hydrogen production load, and P_PcsChg is the expected charging power of the energy storage system; The second calculation formula for the hydrogen production load power is as follows: P_Load =min(P_Load_Max,max(0,P_solar+P_PcsChg)) Among them, P_Load is the hydrogen production load power, P_Load_Max is the maximum available capacity of the hydrogen production load, P_solar is the new energy power generation power, and P_PcsChg is the expected charging power of the energy storage system.

[0014] Furthermore, after adjusting the charging and discharging mode of the energy storage battery according to the battery power state of the large-capacity energy storage system, the charging and discharging power of the energy storage battery is calculated according to the charging and discharging power calculation formula of the energy storage battery with different charging and discharging modes, specifically: When the battery power state of the large-capacity energy storage system is less than or equal to 70%, the energy storage battery is charged first; When the battery power state of the large-capacity energy storage system is greater than 70% and less than 90% and is in the charging process, it is in micro-charging mode; When the battery power state of the large-capacity energy storage system is greater than 90%, it enters the micro-discharge process and is in micro-discharge mode; The calculation formulas for the charging and discharging power of the energy storage battery in different charging and discharging modes are as follows: P_PcsChg=max (-P_solar_Max, (-0.8+1.1×SOC)×P_PcsN), SOC∈ (0, 0.7] P_PcsChg=max (-P_solar_Max, -0.03×P_PcsN), SOC∈ (0.7, 0.9) P_PcsChg=0.03×P_PcsN, SOC∈(0.7, 0.9] Among them, P_PcsChg is the expected charging power of the energy storage system, P_solar_Max is the predicted power of new energy power generation, P_PcsN is the rated power of the large-capacity energy storage system, and SOC is the battery power state of the large-capacity energy storage system; After a period of time, the day with the largest predicted value of renewable energy power generation is selected for full charging and discharging operations. When the energy storage system is fully charged and discharged, the calculation of hydrogen production load power and renewable energy power generation value is the same as that under normal operating conditions.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects: The invention proposes a new energy off-grid operation system, which belongs to the AC off-grid operation scheme. The new energy off-grid operation system architecture connects the large-capacity energy storage system, active / passive filtering system, water electrolysis hydrogen production system, station power system and several new energy AC system branches through the medium-voltage AC bus, realizing efficient energy transmission, flexible scheduling and stable operation. By increasing the operating frequency, the operating cost is reduced.

[0016] Furthermore, the voltage of the medium voltage AC bus is 6kV to 35kV. The medium voltage system has higher transmission capacity and lower loss than the low voltage system. At the same time, it has higher safety and fewer insulation requirements than the high voltage system. The operating frequency is 75Hz to 200Hz. Traditional power systems usually operate at a frequency of 50Hz or 60Hz. The present invention can reduce the cost of related power equipment by appropriately increasing the AC operating frequency while ensuring the reliability of system operation.

[0017] The present invention proposes an operation method of a new energy off-grid operation system, which ensures safe and efficient off-grid hydrogen production, provides a cost-effective solution for local consumption of new energy, and adopts an AC transmission mode to reduce the cost of primary buck-boost equipment and the cost of inductive and capacitive primary components by appropriately increasing the working frequency. The buck-boost equipment can use an iron core transformer, which reduces the cross-sectional area of ​​the iron core after increasing the working frequency, and reduces the overall size of the equipment. Compared with the power electronic converter, the equipment cost is greatly reduced, and the reliability of the equipment operation is improved.

[0018] The present invention proposes a control method for a new energy off-grid operation system, which can reduce the cost of related power equipment by appropriately increasing the AC operation frequency, while ensuring the reliability of system operation, and can ensure the healthy operation of a large-capacity energy storage system on the basis of maximizing the utilization rate of new energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are for explanation purposes only and are not intended to limit the scope of the present invention in any way. In addition, the shapes and proportional dimensions of the components in the drawings are only for illustration purposes to help understand the present invention, and are not intended to specifically limit the shapes and proportional dimensions of the components of the present invention. In the drawings: Figure 1 This is a schematic diagram of a new energy off-grid operation system of the present invention.

[0020] Figure 2 This is a startup flow chart of a new energy off-grid operation system of the present invention.

[0021] Figure 3 The present invention is a shutdown flow chart of a new energy off-grid operation system.

[0022] Figure 4 This is a diagram of the charging and discharging strategy of an energy storage system of a new energy off-grid operation system of the present invention during normal operation.

[0023] Figure 5 This is a charging and discharging strategy diagram of an energy storage system of a new energy off-grid operation system of the present invention. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0025] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only embodiment.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0027] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0028] Embodiment 1 See also Figure 1A new energy off-grid operation system comprises a large-capacity energy storage system branch, an active / passive filtering system branch, a water electrolysis hydrogen production system branch, a station power system branch and several new energy AC system branches; the large-capacity energy storage system branch, the active / passive filtering system branch, the water electrolysis hydrogen production system branch, the station power system branch and several new energy AC system branches are respectively connected to a medium-voltage AC bus; several new energy AC system branches inject the electric energy generated by the new energy power generation into the power grid through the medium-voltage AC bus, and the new energy AC system branch adjusts the power generation power according to the load condition; each system branch transmits energy through the medium-voltage AC bus; the water electrolysis hydrogen production system uses the electric energy generated by the new energy power generation to decompose water into hydrogen and oxygen, and the water electrolysis hydrogen production system adjusts the hydrogen production power by connecting to the medium-voltage AC bus; the active filtering system of the active / passive filtering system branch compensates for the harmonics and reactive power in the power grid, and the passive filtering system filters out the harmonics; the station power system provides power for the new energy off-grid operation system.

[0029] This embodiment realizes efficient transmission and distribution of energy through medium-voltage AC bus, reducing the energy loss of the system. Each system branch can operate independently or work together, and flexibly adjust the power and load according to actual needs. The presence of large-capacity energy storage system and active / passive filtering system improves the stability and reliability of the system and reduces the impact of power grid failure on the system. The water electrolysis hydrogen production system uses the electricity generated by new energy power generation to produce hydrogen, realizing the clean conversion and storage of energy.

[0030] Several new energy AC system branches include photovoltaic AC branches and wind power AC branches. The photovoltaic AC branches include photovoltaic AC switch units, photovoltaic AC transformer units and photovoltaic battery arrays. One end of the photovoltaic AC switch unit is connected to the medium voltage AC busbar, the other end of the photovoltaic AC switch unit is connected to one end of the photovoltaic AC transformer unit, and the other end of the photovoltaic AC transformer unit is connected to the photovoltaic battery array. The photovoltaic AC switch unit includes a photovoltaic AC isolation switch, a photovoltaic AC first grounding switch, a photovoltaic AC circuit breaker and a photovoltaic AC second grounding switch; The photovoltaic AC transformer unit includes a photovoltaic AC step-up and step-down transformer and a photovoltaic AC third grounding switch; The photovoltaic cell array includes a plurality of photovoltaic cell groups, and the photovoltaic cell groups include a photovoltaic inverter, a photovoltaic cell low-voltage circuit breaker and a photovoltaic cell grounding switch; One end of the photovoltaic AC isolation switch is connected to the medium voltage AC busbar, the other end of the photovoltaic AC isolation switch is connected to one end of the photovoltaic AC circuit breaker, the photovoltaic AC first grounding switch is connected between the photovoltaic AC isolation switch and the photovoltaic AC circuit breaker, the other end of the photovoltaic AC circuit breaker is connected to one end of the photovoltaic AC step-up and step-down transformer, and the photovoltaic AC second grounding switch is connected between the photovoltaic AC circuit breaker and the photovoltaic AC step-up and step-down transformer; The other end of the photovoltaic AC step-up and step-down transformer is connected to one end of the photovoltaic cell low-voltage circuit breaker, and the photovoltaic AC third grounding knife switch is connected between the photovoltaic AC step-up and step-down transformer and the photovoltaic cell low-voltage circuit breaker; The other end of the photovoltaic cell low-voltage circuit breaker is connected to the photovoltaic inverter, and the photovoltaic cell grounding switch is connected between the photovoltaic inverter and the photovoltaic cell low-voltage circuit breaker.

[0031] The voltage of the medium voltage AC bus is 6kV to 35kV and the operating frequency is 75Hz to 200Hz.

[0032] The large-capacity energy storage system branch includes a large-capacity energy storage system switch unit, an energy storage converter and an energy storage battery. One end of the large-capacity energy storage system switch unit is connected to the medium-voltage AC bus, and the other end of the large-capacity energy storage system switch unit is connected to the energy storage converter and the energy storage battery. The switch unit of the large-capacity energy storage system includes a large-capacity energy storage system isolation switch, a large-capacity energy storage system first grounding switch, a large-capacity energy storage system AC circuit breaker and a large-capacity energy storage system second grounding switch; One end of the isolation switch of the large-capacity energy storage system is connected to the medium-voltage AC busbar, the other end of the isolation switch of the large-capacity energy storage system is connected to one end of the AC circuit breaker of the large-capacity energy storage system, the first grounding switch of the large-capacity energy storage system is connected between the isolation switch of the large-capacity energy storage system and the AC circuit breaker of the large-capacity energy storage system, the other end of the AC circuit breaker of the large-capacity energy storage system is connected to the energy storage converter and the energy storage battery, and the second grounding switch of the large-capacity energy storage system is connected between the AC circuit breaker of the large-capacity energy storage system and the energy storage converter and the energy storage battery. The branch of the large-capacity energy storage system provides backup power when the new energy generation is insufficient or the power grid fails.

[0033] The active / passive filter system branch includes an active / passive filter system switch unit, an APF converter and an inductor and capacitor. One end of the active / passive filter system switch unit is connected to the medium voltage AC bus, and the other end of the active / passive filter system switch unit is connected to the APF converter and the inductor and capacitor. The active / passive filtering system switch unit includes an active / passive filtering system isolation switch, an active / passive filtering system first grounding switch, an active / passive filtering system AC circuit breaker and an active / passive filtering system second grounding switch; One end of the active / passive filtering system isolation switch is connected to the medium voltage AC bus, the other end of the active / passive filtering system isolation switch is connected to one end of the active / passive filtering system AC circuit breaker, the first grounding switch of the active / passive filtering system is connected between the active / passive filtering system isolation switch and the active / passive filtering system AC circuit breaker, the other end of the active / passive filtering system AC circuit breaker is connected to the APF converter and the inductor and capacitor, and the second grounding switch of the active / passive filtering system is connected between the active / passive filtering system AC circuit breaker and the APF converter and the inductor and capacitor.

[0034] The branch of the water electrolysis hydrogen production system includes a 12N pulsating water electrolysis hydrogen production system, which includes a 12N pulsating water electrolysis hydrogen production system switch unit, a 12N pulsating hydrogen production power supply, an electrolyzer and a hydrogen storage system; one end of the 12N pulsating water electrolysis hydrogen production system switch unit is connected to a medium-voltage AC bus, the other end of the 12N pulsating water electrolysis hydrogen production system switch unit is connected to one end of the 12N pulsating hydrogen production power supply, the other end of the 12N pulsating hydrogen production power supply is connected to one end of the electrolyzer, and the other end of the electrolyzer is connected to the hydrogen storage system; The switch unit of the 12N pulsating water electrolysis hydrogen production system includes a 12N pulsating water electrolysis hydrogen production system isolation switch, a 12N pulsating water electrolysis hydrogen production system first grounding switch, a 12N pulsating water electrolysis hydrogen production system AC circuit breaker and a 12N pulsating water electrolysis hydrogen production system second grounding switch; One end of the 12N pulsating water electrolysis hydrogen production system isolation switch is connected to the medium-voltage AC busbar, the other end of the 12N pulsating water electrolysis hydrogen production system isolation switch is connected to one end of the 12N pulsating water electrolysis hydrogen production system AC circuit breaker, the 12N pulsating water electrolysis hydrogen production system first grounding switch is connected between the 12N pulsating water electrolysis hydrogen production system isolation switch and the 12N pulsating water electrolysis hydrogen production system AC circuit breaker, the other end of the 12N pulsating water electrolysis hydrogen production system AC circuit breaker is connected to one end of the 12N pulsating hydrogen production power supply, and the 12N pulsating water electrolysis hydrogen production system second grounding switch is connected between the 12N pulsating water electrolysis hydrogen production system AC circuit breaker and the 12N pulsating hydrogen production power supply.

[0035] The station power system branch includes a station power system switch unit, a station power system transformer unit, a UPS system and a diesel generator system; one end of the station power system switch unit is connected to the medium voltage AC bus, the other end of the station power system switch unit is connected to one end of the station power system transformer unit, and the other end of the station power system transformer unit is connected to the UPS system and the diesel generator system; The station power system switch unit includes a station power system isolation switch, a station power system first grounding switch, a station power system AC circuit breaker and a station power system second grounding switch; The transformer unit of the station power system includes a step-up and step-down transformer of the station power system and a third grounding switch of the station power system; One end of the station power system isolation switch is connected to the medium voltage AC busbar, the other end of the station power system isolation switch is connected to one end of the station power system AC circuit breaker, the station power system first grounding switch is connected between the station power system isolation switch and the station power system AC circuit breaker, the other end of the station power system AC circuit breaker is connected to one end of the station power system step-up and step-down transformer, and the station power system second grounding switch is connected between the station power system AC circuit breaker and the station power system step-up and step-down transformer; The other end of the step-up / step-down transformer of the station power system is connected to the UPS system and the diesel generator system, and the third grounding switch of the station power system is connected between the step-up / step-down transformer of the station power system and the UPS system and the diesel generator system. The station power system works normally when the renewable energy generation is insufficient or the power grid fails by connecting to the medium-voltage AC bus.

[0036] Embodiment 2 See also Figure 2 and Figure 3 , an operation method of a new energy off-grid operation system, using a new energy off-grid operation system of embodiment 1, comprising the following steps: When the predicted value of renewable energy power generation is greater than the starting power, the renewable energy off-grid operation system enters the operating state according to the starting procedure, and carries out renewable energy power generation and hydrogen production; when the renewable energy power generation and the predicted value of renewable energy power generation are both less than the starting power, and the system is not in the full charge and discharge test of the energy storage system, the renewable energy off-grid operation system stops operating according to the shutdown procedure, and only the station power system retains the minimum control system operation.

[0037] The startup procedure includes the following steps: The power system of the control station of the minimum control system is started to supply power to the control equipment of the entire station; After the station power system is operating normally, start all secondary control systems and check the health status of primary equipment; If the number of healthy primary devices meets the startup requirements and the renewable energy power generation is greater than the allowed startup power threshold, the primary devices will be officially started; Start the large-capacity energy storage system, active / passive filtering system, new energy power generation system and water electrolysis hydrogen production system in sequence. If the equipment fails to start during the startup process, the startup is terminated and the system startup failure information is transmitted. Otherwise, the system startup success information is transmitted. The outage procedure includes the following steps: Shut down the hydrogen production system, shut down the new energy power generation system, shut down the active / passive filtering system, shut down the large-capacity energy storage system, shut down the secondary control system of the primary equipment, and only keep the minimum control system working.

[0038] Embodiment 3 See also Figure 4 and Figure 5 A method for controlling hydrogen production in a new energy off-grid operation system, using a new energy off-grid operation system of the first embodiment, includes: when the maximum available capacity of the hydrogen production load is greater than or equal to the predicted power of the new energy power generation, the photovoltaic of the new energy AC system generates electricity at the maximum predicted power, and the control strategy of the hydrogen production load power is specifically as follows: According to the battery power status of the large-capacity energy storage system, after adjusting the charging and discharging mode of the energy storage battery, the charging and discharging power of the energy storage battery is calculated according to the charging and discharging power calculation formula of the energy storage battery with different charging and discharging modes; The hydrogen production load power is calculated according to the first calculation formula of the hydrogen production load power using the charging and discharging power of the energy storage battery. When the hydrogen production load power is less than the start threshold, the hydrogen production power supply is locked until the hydrogen production load power is greater than the start threshold; The first calculation formula for hydrogen production load power is as follows: P_Load =min(P_Load_Max,max(0,P_solar_Max+P_PcsChg)) Among them, P_Load is the hydrogen production load power, P_Load_Max is the maximum available capacity of the hydrogen production load, P_solar_Max is the predicted power of new energy power generation, and P_PcsChg is the expected charging power of the energy storage system; When the maximum available capacity of hydrogen production load is less than the predicted power of new energy power generation, the specific strategy of hydrogen production load and photovoltaic power generation is as follows: According to the battery power state of the large-capacity energy storage system, the charging and discharging mode of the energy storage battery is determined, and the charging and discharging power of the energy storage battery is calculated according to the charging and discharging mode of the energy storage battery; The new energy power generation power is calculated according to the new energy power generation power adjustment formula using the energy storage battery charging and discharging power, and the hydrogen production load power is calculated according to the new energy power generation power and the second calculation formula of the hydrogen production load power. When the hydrogen production load power is less than the start threshold, the hydrogen production power supply is locked until the hydrogen production load power is greater than the start threshold; The power regulation formula of renewable energy generation is as follows: P_solar =min(P_solar_Max,max(0,P_Load_Max-P_PcsChg)) Among them, P_solar is the power generated by new energy, P_solar_Max is the predicted power generated by new energy, P_Load_Max is the maximum available capacity of hydrogen production load, and P_PcsChg is the expected charging power of the energy storage system; The second calculation formula for hydrogen production load power is as follows: P_Load =min(P_Load_Max,max(0,P_solar+P_PcsChg)) Among them, P_Load is the hydrogen production load power, P_Load_Max is the maximum available capacity of the hydrogen production load, P_solar is the new energy power generation power, and P_PcsChg is the expected charging power of the energy storage system.

[0039] According to the battery power status of the large-capacity energy storage system, after adjusting the charging and discharging mode of the energy storage battery, the charging and discharging power of the energy storage battery is calculated according to the charging and discharging power calculation formula of the energy storage battery in different charging and discharging modes, specifically: When the battery power state of the large-capacity energy storage system is less than or equal to 70%, the energy storage battery is charged first; When the battery power state of the large-capacity energy storage system is greater than 70% and less than 90% and is in the charging process, it is in micro-charging mode; When the battery power state of the large-capacity energy storage system is greater than 90%, it enters the micro-discharge process and is in micro-discharge mode; The calculation formulas for charging and discharging power of energy storage batteries in different charging and discharging modes are as follows: P_PcsChg=max (-P_solar_Max, (-0.8+1.1×SOC)×P_PcsN), SOC∈ (0, 0.7] P_PcsChg=max (-P_solar_Max, -0.03×P_PcsN), SOC∈ (0.7, 0.9) P_PcsChg=0.03×P_PcsN, SOC∈(0.7, 0.9] Among them, P_PcsChg is the expected charging power of the energy storage system, P_solar_Max is the predicted power of new energy power generation, P_PcsN is the rated power of the large-capacity energy storage system, and SOC is the battery power status of the large-capacity energy storage system. After a period of time, the day with the largest predicted value of new energy power generation is selected for full charging and discharging operations. When the energy storage system is fully charged and discharged, the calculation of hydrogen production load power and new energy power generation power value is the same as that under normal operating conditions.

[0040] Embodiment 4 This embodiment is a new energy off-grid operation system, which adopts the AC transmission mode. The AC system operating frequency is selected from 75Hz to 200Hz. The specific frequency selection is determined based on the overall cost of the equipment. The overall system architecture is as follows: Figure 1 The system consists of the following parts: Several new energy AC branches (taking photovoltaic as an example): including switch units, transformer units and photovoltaic cell arrays. The switch unit includes isolation switch QS1, grounding switch D1, AC circuit breaker F1, and grounding switch D2; the transformer unit includes step-up (step-down) transformer and grounding switch D3; the photovoltaic cell array consists of M photovoltaic cell groups and their connected photovoltaic inverters, low-voltage circuit breakers and grounding switches.

[0041] Large-capacity energy storage system branch: includes switch unit, energy storage converter and energy storage battery.

[0042] Active / passive filtering system: includes switch unit, APF converter, inductor, capacitor and other components.

[0043] 12N water electrolysis hydrogen production system: includes switch unit, 12N pulsating hydrogen production power supply, electrolyzer, and hydrogen storage system.

[0044] Station power system: includes switch unit, transformer unit, UPS system and diesel generator system.

[0045] As the energy transmission and distribution center of the entire system, the medium-voltage AC busbar can carry large currents and voltages to meet the needs of large-capacity energy storage, new energy power generation, and hydrogen production by electrolysis of water. Through the medium-voltage AC busbar, each system branch can achieve efficient energy transmission and flexible scheduling.

[0046] Large-capacity energy storage systems (such as battery energy storage systems) are connected to the medium-voltage AC bus through branches, which can provide backup power when renewable energy generation is insufficient or when the grid fails, ensuring stable operation of the system. Energy storage systems can also be used to smooth fluctuations in renewable energy generation and improve the power quality and reliability of the entire system.

[0047] The active filter system can dynamically compensate for harmonics and reactive power in the power grid and improve the power quality. The passive filter system uses fixed inductors, capacitors and other components to filter out harmonics and reduce harmonic pollution in the power grid. The combination of the two can more effectively improve the power quality and stability of the system.

[0048] The water electrolysis hydrogen production system uses the electricity generated by renewable energy to decompose water into hydrogen and oxygen, realizing energy conversion and storage. By connecting to the medium-voltage AC bus, the water electrolysis hydrogen production system can flexibly adjust the hydrogen production power and work in conjunction with renewable energy power generation and energy storage systems.

[0049] The station power system provides the necessary power support for the entire renewable energy off-grid operation system, including power supply for lighting, control, communication and other equipment. By connecting to the medium-voltage AC bus, the station power system can ensure normal operation when renewable energy generation is insufficient or the grid fails.

[0050] Several new energy AC system branches (such as photovoltaic power generation systems, wind power generation systems, etc.) are connected to the medium-voltage AC busbar through transformers and other equipment to inject the electricity generated by new energy into the grid. These new energy systems can flexibly adjust the power generation according to weather and load conditions to maximize the use of energy.

[0051] When the predicted value of the power generated by renewable energy is less than the starting power, the system is in a shutdown state. Except for the minimum control system, which only keeps the power used by the station, all other equipment control systems are stopped to minimize power loss. When the minimum control system predicts that the power generated by renewable energy is greater than the starting power of the system, the startup process is completed step by step to put the system into operation and start hydrogen production by renewable energy power generation.

[0052] (1) First, the power system of the minimum control system control station is started to meet the power supply requirements of the control equipment of the entire station; (2) After the station power system is operating normally, start the secondary control system of all core equipment to detect the health status of the equipment; (3) After the core equipment self-checks and has no faults (or the healthy number meets the startup requirements), and the startup conditions are met, if the renewable energy power generation is greater than the allowable startup power threshold, the equipment will be officially started once; (4) Start the large-capacity energy storage system, active / passive filtering system, new energy power generation system and hydrogen production system in sequence. If a certain type of equipment fails to start during the startup process, the startup is terminated and the system startup failure information is sent; otherwise, the system startup success information is sent.

[0053] System startup process Figure 2 As shown, in the system operation state, when the renewable energy power generation and the power generation prediction are both less than the starting power, and the system does not belong to the full charge and discharge test of the energy storage system, the control system automatically operates the operating system to the shutdown state according to the steps.

[0054] System shutdown process Figure 3 The shutdown sequence is: (1) Shut down the hydrogen production system; (2) Shut down new energy power generation systems; (3) Shut down the active / passive filtering system; (4) Shut down large-capacity energy storage systems; (5) Shut down the secondary control system of the core equipment and keep only the minimum control system working.

[0055] The following control strategies are implemented when the system is producing hydrogen normally: Based on the current maximum capacity of hydrogen production load, the current SOC of large-capacity energy storage system and the predicted maximum power generation value of new energy such as photovoltaic, the power of various equipment is comprehensively determined. The specific implementation strategy is as follows: SOC (State of Charge) refers to the battery's state of charge, usually expressed as a percentage, reflecting the ratio of the battery's remaining charge to the battery's total capacity. For example, a battery with a SOC of 50% means that its remaining charge is half of its total capacity.

[0056] (1) When the maximum available capacity of the hydrogen production load P_Load_Max is greater than or equal to the predicted power of renewable energy generation P_solar_Max, photovoltaic power generation is carried out at the maximum predicted power, and the hydrogen production load PLoad is set according to the following situations.

[0057] When the SOC of the large-capacity energy storage system battery is less than or equal to 70%, the energy storage battery is charged first; P_PcsChg=max (-P_solar_Max, (-0.8+1.1×SOC)×P_PcsN), SOC∈ (0, 0.7] P_PcsChg is the expected charging power of the energy storage system; P_PcsN is the rated power of the large-capacity energy storage system; SOC is the remaining power of the large-capacity energy storage system (1 is full capacity).

[0058] When the SOC of the large-capacity energy storage system battery is greater than 70% and less than 90% and is in the charging process, the charging power of the energy storage battery is fixed at 0.03 times the rated current of the energy storage and is in micro-charging mode.

[0059] P_PcsChg=max (-P_solar_Max, -0.03×P_PcsN), SOC∈ (0.7, 0.9) When the SOC of the large-capacity energy storage system battery is greater than 90%, it enters the micro-discharge process, and the energy storage battery discharge power is fixed at 0.03 times the rated current of the energy storage, and is in micro-discharge mode.

[0060] P_PcsChg=0.03×P_PcsN, SOC∈(0.7, 0.9] After calculating the charging and discharging power of the energy storage battery, the hydrogen production load power is calculated using the following formula: P_Load =min(P_Load_Max,max(0,P_solar_Max+P_PcsChg)) When the calculated P_Load is less than the start threshold, the hydrogen production power supply is locked until P_Load is greater than the start threshold.

[0061] (2) When the maximum available capacity of the hydrogen production load P_Load_Max is less than the predicted power of renewable energy power generation P_solar_Max, the hydrogen production load and photovoltaic power generation power are determined according to the following strategy.

[0062] When the SOC of the large-capacity energy storage system battery is less than or equal to 70%, the energy storage battery is charged first; P_PcsChg=max (-P_solar_Max, (-0.8+1.1×SOC)×P_PcsN), SOC∈ (0, 0.7] When the SOC of the large-capacity energy storage system battery is greater than 70% and less than 90% and is in the charging process, the charging power of the energy storage battery is fixed at 0.03 times the rated current of the energy storage and is in micro-charging mode.

[0063] P_PcsChg=max (-P_solar_Max, -0.03×P_PcsN), SOC∈ (0.7, 0.9) When the SOC of the large-capacity energy storage system battery is greater than 90%, it enters the micro-discharge process, and the energy storage battery discharge power is fixed at 0.03 times the rated current of the energy storage, and is in micro-discharge mode.

[0064] P_PcsChg=0.03×P_PcsN, SOC∈(0.7, 0.9] After calculating the charging and discharging power of the energy storage battery, adjust the power of the new energy generation so that its output power is: P_solar =min(P_solar_Max,max(0,P_Load_Max-P_PcsChg)) The hydrogen production load power is calculated using the following formula: P_Load =min(P_Load_Max,max(0,P_solar+P_PcsChg)) When the calculated P_Load is less than the start threshold, the hydrogen production power supply is locked until P_Load is greater than the start threshold.

[0065] During normal operation, the charging and discharging power characteristics of the energy storage system are as follows: Figure 4 shown.

[0066] After the energy storage system battery has been running for a long period of time, it often needs to be fully charged and discharged. Therefore, it is necessary to set a full charging and discharging strategy. In principle, full charging and discharging operations should be performed as much as possible according to battery demand. The full charging and discharging strategy provided in this embodiment is: after a long period of time, select the day with the largest predicted value of new energy power generation to perform full charging and discharging operations. When the energy storage system is fully charged and discharged, it only affects the output power of the energy storage system. The calculation of hydrogen production load power and new energy power generation power value is the same as normal operating conditions. The energy storage battery is fully charged and discharged using the following method: Figure 5 The power curve shown is carried out.

[0067] Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but rather with reference to the preceding claims and the full scope of equivalents to which such claims are entitled. For the purpose of comprehensiveness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the preceding claims is not intended to be a disclaimer of such subject matter, nor should it be considered that the applicants did not consider such subject matter to be part of the disclosed inventive subject matter.

[0068] The above content is a further detailed description of the present invention. It cannot be determined that the specific implementation methods of the present invention are limited to these. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, they can also make several simple deductions or substitutions, which should be regarded as belonging to the protection scope of the present invention determined by the submitted claims.

Claims

1. A new energy off-grid operation system, characterized in that: It includes a large-capacity energy storage system branch, an active / passive filtering system branch, a water electrolysis hydrogen production system branch, a station power system branch and several new energy AC system branches; the large-capacity energy storage system branch, the active / passive filtering system branch, the water electrolysis hydrogen production system branch, the station power system branch and several new energy AC system branches are respectively connected to the medium-voltage AC busbar; Several new energy AC system branches inject the electric energy generated by new energy power generation into the power grid through the medium-voltage AC bus. The new energy AC system branches adjust the power generation according to the load conditions. Each system branch transmits energy through the medium-voltage AC bus. The water electrolysis hydrogen production system uses the electric energy generated by new energy power generation to decompose water into hydrogen and oxygen. The water electrolysis hydrogen production system adjusts the hydrogen production power by connecting to the medium-voltage AC bus. The active filter system of the active / passive filter system branch compensates for the harmonics and reactive power in the power grid, and the passive filter system filters out the harmonics. The station power system provides power for the new energy off-grid operation system.

2. A new energy off-grid operation system according to claim 1, characterized in that: The several new energy AC system branches include a photovoltaic AC branch and a wind power AC branch, the photovoltaic AC branch includes a photovoltaic AC switch unit, a photovoltaic AC transformer unit and a photovoltaic battery array, one end of the photovoltaic AC switch unit is connected to the medium voltage AC bus, the other end of the photovoltaic AC switch unit is connected to one end of the photovoltaic AC transformer unit, and the other end of the photovoltaic AC transformer unit is connected to the photovoltaic battery array; The photovoltaic AC switch unit includes a photovoltaic AC isolation switch, a photovoltaic AC first grounding switch, a photovoltaic AC circuit breaker and a photovoltaic AC second grounding switch; The photovoltaic AC transformation unit includes a photovoltaic AC step-up and step-down transformer and a photovoltaic AC third grounding switch; The photovoltaic cell array includes a plurality of photovoltaic cell groups, and the photovoltaic cell groups include a photovoltaic inverter, a photovoltaic cell low-voltage circuit breaker and a photovoltaic cell grounding switch; One end of the photovoltaic AC isolation switch is connected to the medium voltage AC busbar, the other end of the photovoltaic AC isolation switch is connected to one end of the photovoltaic AC circuit breaker, the photovoltaic AC first grounding switch is connected between the photovoltaic AC isolation switch and the photovoltaic AC circuit breaker, the other end of the photovoltaic AC circuit breaker is connected to one end of the photovoltaic AC step-up and step-down transformer, and the photovoltaic AC second grounding switch is connected between the photovoltaic AC circuit breaker and the photovoltaic AC step-up and step-down transformer; The other end of the photovoltaic AC step-up / step-down transformer is connected to one end of the photovoltaic cell low-voltage circuit breaker, and the photovoltaic AC third grounding switch is connected between the photovoltaic AC step-up / step-down transformer and the photovoltaic cell low-voltage circuit breaker; The other end of the photovoltaic cell low-voltage circuit breaker is connected to the photovoltaic inverter, and the photovoltaic cell grounding switch is connected between the photovoltaic inverter and the photovoltaic cell low-voltage circuit breaker; The voltage of the medium voltage AC bus is 6 kV to 35 kV, and the operating frequency is 75 Hz to 200 Hz.

3. A new energy off-grid operation system according to claim 1, characterized in that: The large-capacity energy storage system branch includes a large-capacity energy storage system switch unit, an energy storage converter and an energy storage battery, one end of the large-capacity energy storage system switch unit is connected to the medium-voltage AC bus, and the other end of the large-capacity energy storage system switch unit is connected to the energy storage converter and the energy storage battery; The large-capacity energy storage system switch unit includes a large-capacity energy storage system isolation switch, a large-capacity energy storage system first grounding switch, a large-capacity energy storage system AC circuit breaker and a large-capacity energy storage system second grounding switch; One end of the large-capacity energy storage system isolation switch is connected to the medium-voltage AC busbar, the other end of the large-capacity energy storage system isolation switch is connected to one end of the large-capacity energy storage system AC circuit breaker, the first grounding switch of the large-capacity energy storage system is connected between the large-capacity energy storage system isolation switch and the large-capacity energy storage system AC circuit breaker, the other end of the large-capacity energy storage system AC circuit breaker is connected to the energy storage inverter and the energy storage battery, and the second grounding switch of the large-capacity energy storage system is connected between the large-capacity energy storage system AC circuit breaker and the energy storage inverter and the energy storage battery.

4. A new energy off-grid operation system according to claim 1, characterized in that: The active / passive filtering system branch includes an active / passive filtering system switch unit, an APF converter and an inductor and capacitor, one end of the active / passive filtering system switch unit is connected to the medium voltage AC bus, and the other end of the active / passive filtering system switch unit is connected to the APF converter and the inductor and capacitor; The active / passive filtering system switch unit includes an active / passive filtering system isolation switch, an active / passive filtering system first grounding switch, an active / passive filtering system AC circuit breaker and an active / passive filtering system second grounding switch; One end of the active / passive filtering system isolation switch is connected to the medium voltage AC bus, the other end of the active / passive filtering system isolation switch is connected to one end of the active / passive filtering system AC circuit breaker, the first grounding switch of the active / passive filtering system is connected between the active / passive filtering system isolation switch and the active / passive filtering system AC circuit breaker, the other end of the active / passive filtering system AC circuit breaker is connected to the APF converter and the inductor and capacitor, and the second grounding switch of the active / passive filtering system is connected between the active / passive filtering system AC circuit breaker and the APF converter and the inductor and capacitor.

5. A new energy off-grid operation system according to claim 1, characterized in that: The branch of the water electrolysis hydrogen production system includes a 12N pulsating water electrolysis hydrogen production system, which includes a 12N pulsating water electrolysis hydrogen production system switch unit, a 12N pulsating hydrogen production power supply, an electrolyzer and a hydrogen storage system; one end of the 12N pulsating water electrolysis hydrogen production system switch unit is connected to a medium-voltage AC bus, the other end of the 12N pulsating water electrolysis hydrogen production system switch unit is connected to one end of the 12N pulsating hydrogen production power supply, the other end of the 12N pulsating hydrogen production power supply is connected to one end of the electrolyzer, and the other end of the electrolyzer is connected to the hydrogen storage system; The 12N pulsating water electrolysis hydrogen production system switch unit includes a 12N pulsating water electrolysis hydrogen production system isolation switch, a 12N pulsating water electrolysis hydrogen production system first grounding switch, a 12N pulsating water electrolysis hydrogen production system AC circuit breaker and a 12N pulsating water electrolysis hydrogen production system second grounding switch; One end of the 12N pulsating water electrolysis hydrogen production system isolation switch is connected to the medium-voltage AC bus, the other end of the 12N pulsating water electrolysis hydrogen production system isolation switch is connected to one end of the 12N pulsating water electrolysis hydrogen production system AC circuit breaker, the 12N pulsating water electrolysis hydrogen production system first grounding switch is connected between the 12N pulsating water electrolysis hydrogen production system isolation switch and the 12N pulsating water electrolysis hydrogen production system AC circuit breaker, the other end of the 12N pulsating water electrolysis hydrogen production system AC circuit breaker is connected to one end of the 12N pulsating hydrogen production power supply, and the 12N pulsating water electrolysis hydrogen production system second grounding switch is connected between the 12N pulsating water electrolysis hydrogen production system AC circuit breaker and the 12N pulsating hydrogen production power supply.

6. A new energy off-grid operation system according to claim 1, characterized in that: The station power system branch includes a station power system switch unit, a station power system transformer unit, a UPS system and a diesel generator system; one end of the station power system switch unit is connected to the medium voltage AC bus, the other end of the station power system switch unit is connected to one end of the station power system transformer unit, and the other end of the station power system transformer unit is connected to the UPS system and the diesel generator system; The station power system switch unit includes a station power system isolation switch, a station power system first grounding switch, a station power system AC circuit breaker and a station power system second grounding switch; The station power system transformer unit includes a station power system step-up and step-down transformer and a station power system third grounding switch; One end of the station power system isolation switch is connected to the medium voltage AC busbar, the other end of the station power system isolation switch is connected to one end of the station power system AC circuit breaker, the station power system first grounding switch is connected between the station power system isolation switch and the station power system AC circuit breaker, the other end of the station power system AC circuit breaker is connected to one end of the station power system step-up and step-down transformer, and the station power system second grounding switch is connected between the station power system AC circuit breaker and the station power system step-up and step-down transformer; The other end of the step-up and step-down transformer of the station power system is connected to the UPS system and the diesel generator system, and the third grounding switch of the station power system is connected between the step-up and step-down transformer of the station power system and the UPS system and the diesel generator system.

7. A method for operating a new energy off-grid operation system, using a new energy off-grid operation system as claimed in any one of claims 1 to 6, characterized in that: The steps include: When the predicted value of renewable energy power generation is greater than the starting power, the renewable energy off-grid operation system enters the operating state according to the starting procedure, and carries out renewable energy power generation and hydrogen production; when the renewable energy power generation and the predicted value of renewable energy power generation are both less than the starting power, and the system is not in the full charge and discharge test of the energy storage system, the renewable energy off-grid operation system stops operating according to the shutdown procedure, and only the station power system retains the minimum control system operation.

8. The operating method of a new energy off-grid operating system according to claim 7, characterized in that: The startup procedure includes the following steps: The power system of the control station of the minimum control system is started to supply power to the control equipment of the entire station; After the station power system is operating normally, start all secondary control systems and check the health status of primary equipment; If the number of healthy primary devices meets the startup requirements and the renewable energy power generation is greater than the allowed startup power threshold, the primary devices will be officially started; Start the large-capacity energy storage system, active / passive filtering system, new energy power generation system and water electrolysis hydrogen production system in sequence. If the equipment fails to start during the startup process, the startup is terminated and the system startup failure information is transmitted. Otherwise, the system startup success information is transmitted. The shutdown procedure includes the following steps: Shut down the hydrogen production system, shut down the new energy power generation system, shut down the active / passive filtering system, shut down the large-capacity energy storage system, shut down the secondary control system of the primary equipment, and only keep the minimum control system working.

9. A control method for a new energy off-grid operation system, using a new energy off-grid operation system as claimed in any one of claims 1 to 6, characterized in that: When the maximum available capacity of the hydrogen production load is greater than or equal to the predicted power of new energy power generation, the photovoltaic power of the new energy AC system generates electricity at the maximum predicted power. The specific control strategy of the hydrogen production load power is: According to the battery power status of the large-capacity energy storage system, after adjusting the charging and discharging mode of the energy storage battery, the charging and discharging power of the energy storage battery is calculated according to the charging and discharging power calculation formula of the energy storage battery with different charging and discharging modes; The hydrogen production load power is calculated according to the first calculation formula of the hydrogen production load power using the charging and discharging power of the energy storage battery. When the hydrogen production load power is less than the start threshold, the hydrogen production power supply is locked until the hydrogen production load power is greater than the start threshold; The first calculation formula of the hydrogen production load power is as follows: P_Load =min(P_Load_Max,max(0,P_solar_Max+P_PcsChg)) Among them, P_Load is the hydrogen production load power, P_Load_Max is the maximum available capacity of the hydrogen production load, P_solar_Max is the predicted power of new energy power generation, and P_PcsChg is the expected charging power of the energy storage system; When the maximum available capacity of hydrogen production load is less than the predicted power of new energy power generation, the specific strategy of hydrogen production load and photovoltaic power generation is as follows: According to the battery power state of the large-capacity energy storage system, the charging and discharging mode of the energy storage battery is determined, and the charging and discharging power of the energy storage battery is calculated according to the charging and discharging mode of the energy storage battery; The new energy power generation power is calculated according to the new energy power generation power adjustment formula using the energy storage battery charging and discharging power, and the hydrogen production load power is calculated according to the new energy power generation power and the second calculation formula of the hydrogen production load power. When the hydrogen production load power is less than the start threshold, the hydrogen production power supply is locked until the hydrogen production load power is greater than the start threshold; The new energy power generation power adjustment formula is as follows: P_solar =min(P_solar_Max,max(0,P_Load_Max-P_PcsChg)) Among them, P_solar is the power generated by new energy, P_solar_Max is the predicted power generated by new energy, P_Load_Max is the maximum available capacity of hydrogen production load, and P_PcsChg is the expected charging power of the energy storage system; The second calculation formula for the hydrogen production load power is as follows: P_Load =min(P_Load_Max,max(0,P_solar+P_PcsChg)) Among them, P_Load is the hydrogen production load power, P_Load_Max is the maximum available capacity of the hydrogen production load, P_solar is the new energy power generation power, and P_PcsChg is the expected charging power of the energy storage system.

10. A control method for a new energy off-grid operation system according to claim 9, characterized in that: According to the battery power state of the large-capacity energy storage system, after adjusting the charging and discharging mode of the energy storage battery, the charging and discharging power of the energy storage battery is calculated according to the charging and discharging power calculation formula of the energy storage battery in different charging and discharging modes, specifically: When the battery power state of the large-capacity energy storage system is less than or equal to 70%, the energy storage battery is charged first; When the battery power state of the large-capacity energy storage system is greater than 70% and less than 90% and is in the charging process, it is in micro-charging mode; When the battery power state of the large-capacity energy storage system is greater than 90%, it enters the micro-discharge process and is in micro-discharge mode; The calculation formulas for the charging and discharging power of the energy storage battery in different charging and discharging modes are as follows: P_PcsChg=max (-P_solar_Max, (-0.8+1.1×SOC)×P_PcsN), SOC∈ (0, 0.7] P_PcsChg=max (-P_solar_Max, -0.03×P_PcsN), SOC∈ (0.7, 0.9) P_PcsChg=0.03×P_PcsN, SOC∈(0.7, 0.9] Among them, P_PcsChg is the expected charging power of the energy storage system, P_solar_Max is the predicted power of new energy power generation, P_PcsN is the rated power of the large-capacity energy storage system, and SOC is the battery power state of the large-capacity energy storage system; After a period of time, the day with the largest predicted value of renewable energy power generation is selected for full charging and discharging operations. When the energy storage system is fully charged and discharged, the calculation of hydrogen production load power and renewable energy power generation value is the same as that under normal operating conditions.

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