VSG collaborative control method and device for hydrogen storage DC microgrid

Abstract

A VSG collaborative control method and device for a hydrogen storage DC microgrid, establishing a current reference value provided by a current loop reference current control module of a DC-DC converter in an electric storage device to the current loop of a DC-DC converter in the electric storage device, and establishing a current reference value provided by a current loop reference current control module of a DC-DC converter in a hydrogen storage device to the current loop of a fuel cell or to the current loop of a DC-DC converter of an electrolyzer; based on state space equations, using state variables, with the goal of optimizing various indicators of collaborative control, the parameters of the current loop reference current control module of the DC-DC converter in the electric storage device and the current loop reference current control module of the DC-DC converter in the hydrogen storage device are adjusted to achieve VSG collaborative control of a hydrogen storage DC microgrid, solving the problem that the current source control strategy adopted by a traditional distributed energy hydrogen production system cannot meet the inertia requirements of a high proportion of new energy access systems.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy control, and in particular, relates to a virtual synchronous generator (VSG) collaborative control method and system for a hydrogen storage DC microgrid. Background Art

[0002] With the development of new energy power generation technology, the corresponding research on DC microgrids is also deepening. Compared with traditional AC microgrids, DC microgrids do not have problems such as synchronization, harmonics and frequency control, have low control complexity, high operating stability, and can be used as an independent system to achieve grid-connected or island operation. It has gradually become the best way to absorb new energy.

[0003] However, the output of renewable energy is random and uncertain, which reduces the safe and stable operation capability of DC microgrid. The access of energy storage system can effectively solve this problem. Although traditional energy storage technologies such as electrochemical energy storage have high power density, their energy density is low, and it is difficult to balance high energy density and economic operation. As a clean energy with high energy density, the reasonable access of hydrogen energy to DC microgrid can not only improve the economy of the system, but also improve its renewable energy absorption capacity. In the existing technology, the current source control method is mainly used for distributed energy hydrogen production system, which cannot provide voltage and frequency support to meet the inertia requirements of high-proportion new energy access system. The use of network control technology can provide certain voltage and frequency support for the system and improve system stability. Network technology mainly includes droop control, virtual synchronous generator control, matching control, virtual oscillator control, etc. At present, the mainstream is virtual synchronous generator control. At the same time, compared with wind power, photovoltaic and other energy sources with large output fluctuations, energy storage system can be used as an ideal carrier of network control technology because of its relatively independent energy source, and its hardware form is basically the same as conventional energy storage. The main difference between grid-type energy storage and conventional energy storage is that the grid-type control strategy has higher requirements for the overcurrent capacity of power electronic devices and the heat dissipation performance of equipment, and can better play the role of voltage source support. Grid-type energy storage can effectively improve the problems of short-circuit capacity and lack of rotational inertia caused by the high proportion of new energy access systems, and play a supporting role in the construction of new power systems in the future. Summary of the invention

[0004] In order to solve the deficiencies in the prior art, the present invention provides a VSG collaborative control method and device for a hydrogen storage DC microgrid, which fully combines the battery energy storage and hydrogen energy storage models, and at the same time reasonably formulates a corresponding coordinated control method based on the characteristics of the response speed of the hybrid energy storage system, thereby solving the problem that the current source control strategy adopted by the traditional distributed energy hydrogen production system cannot meet the inertia requirements of the high proportion of new energy access system.

[0005] The present invention adopts the following technical solution.

[0006] The present invention proposes a VSG coordinated control method for a hydrogen-containing DC storage microgrid, wherein the hydrogen-containing DC storage microgrid includes an electric storage device and a hydrogen storage system, wherein the electric storage device includes a DC-DC converter and a battery, and the hydrogen storage device includes an electrolyzer and its corresponding DC-DC converter, a hydrogen storage tank, a fuel cell and its corresponding DC-DC converter; the controller of each DC-DC converter includes a current loop; including:

[0007] Establish a current loop reference current control module for the DC-DC converter in the power storage device; the current loop reference current control module for the DC-DC converter in the power storage device uses the actual voltage and voltage reference value of the DC bus, the actual current and current reference value of the hydrogen storage DC microgrid entering the DC bus as input data, and when the battery charge state meets When the current loop reference current control module provides the current reference value to the current loop of the DC-DC converter in the power storage device, the current reference value is the difference between the battery steady-state current reference value and the battery output current when the hydrogen storage DC microgrid reaches steady-state operation; when the battery charge state meets or When the current loop reference current control module provides a current reference value to the current loop of the DC-DC converter in the power storage device, which is the difference between the set battery current reference value and the battery output current;

[0008] Establish a current loop reference current control module for the DC-DC converter in the hydrogen storage device; the current loop reference current control module for the DC-DC converter in the hydrogen storage device takes the set battery current reference value, the current reference value of the hydrogen storage DC microgrid entering the DC bus, the current of the DC bus entering the electrolyzer, and the current of the fuel cell entering the DC bus as input data. When the battery charge state meets The current loop reference current control module processes the input data based on the synchronous generator rotor mechanical equation to determine the steady-state current reference value of the hydrogen storage when the hydrogen storage DC microgrid reaches steady-state operation. or When the current loop reference current control module processes the input data and the set battery current reference value based on the synchronous generator rotor mechanical equation to determine the hydrogen storage steady-state current reference value when the hydrogen storage DC microgrid reaches steady-state operation; when the hydrogen storage steady-state current reference value When the hydrogen storage steady-state current reference value is positive, the current loop reference current control module determines the current reference value provided by the current loop reference current control module to the current loop of the DC-DC converter of the fuel cell by using the hydrogen storage steady-state current reference value and the fuel cell output current; when the hydrogen storage steady-state current reference value is negative, the current loop reference current control module determines the current reference value provided by the current loop reference current control module to the current loop of the DC-DC converter of the electrolyzer by using the hydrogen storage steady-state current reference value and the electrolyzer input current;

[0009] in, is the state of charge of the battery, is the upper limit of the state of charge, It is the lower limit of the charge state;

[0010] The state variables are formed by the voltage difference between the actual voltage of the DC bus and the voltage reference value, the current difference between the actual current of the hydrogen storage DC microgrid entering the DC bus and the current reference value, and the current of the battery entering the DC bus. Based on the state space equation, the state variables are used to adjust the parameters of the current loop reference current control module of the DC-DC converter in the electricity storage device and the current loop reference current control module of the DC-DC converter in the hydrogen storage device with the goal of optimizing various indicators of collaborative control. The VSG collaborative control of the hydrogen storage DC microgrid is carried out with the adjusted current loop reference current control module of the DC-DC converter in the electricity storage device and the current loop reference current control module of the DC-DC converter in the hydrogen storage device.

[0011] Preferably, the current loop reference current control module of the DC-DC converter in the power storage device includes: a voltage speed regulator, a dynamic shutdown unit, and a first state of charge monitoring unit;

[0012] The voltage regulator provides a first current signal to the first state of charge monitoring unit according to the difference between the actual voltage of the DC bus and the voltage reference value;

[0013] The dynamic shutdown unit uses the difference between the current reference value of the hydrogen-containing DC storage microgrid entering the DC bus and the actual current of the hydrogen-containing DC storage microgrid entering the DC bus as the second current signal of the first charge state monitoring unit;

[0014] The first state of charge monitoring unit determines the steady-state current reference value of the battery when the hydrogen storage DC microgrid reaches steady-state operation according to the inverse of the sum of the first current signal and the second current signal. At the same time, the first state of charge monitoring unit obtains the set battery current reference value. When the battery state of charge meets When the state of charge of the battery meets the condition, the current reference value provided by the first state of charge monitoring unit to the current loop is the difference between the steady-state current reference value of the battery and the output current of the battery; when the state of charge of the battery meets the condition or When the current loop reference current control module provides the current reference value to the current loop, the current reference value is the difference between the set battery current reference value and the battery output current.

[0015] Preferably, the voltage regulator uses the actual voltage of the DC bus With voltage reference The voltage difference is the input signal, and the first current signal is obtained by the following relationship:

[0016] ,

[0017] In the formula, is the first current signal, It is the parameter of voltage regulator.

[0018] Preferably, the dynamic shutdown unit uses the current difference between the current reference value of the hydrogen storage DC microgrid entering the DC bus and the actual current of the hydrogen storage DC microgrid entering the DC bus as an output signal, satisfying the following relationship:

[0019] ,

[0020] In the formula, is the second current signal, is the current reference value of the hydrogen storage DC microgrid entering the DC bus, The current that flows into the DC bus of the hydrogen storage DC microgrid;

[0021] In addition, the current reference value and the current difference of the hydrogen storage DC microgrid entering the DC bus in the dynamic shutdown unit satisfy the following relationship:

[0022] ,

[0023] In the formula, is the strategy coefficient of the dynamic shutdown unit.

[0024] Preferably, when the hydrogen storage DC microgrid reaches steady-state operation, the steady-state current reference value of the battery satisfies the following relationship:

[0025] ,

[0026] In the formula, is the reference value of the battery steady-state current, The battery output voltage and the actual voltage of the DC bus The proportionality coefficient between is the actual voltage of the DC bus With voltage reference The voltage difference, is the current reference value of the hydrogen storage DC microgrid entering the DC bus, It is the actual current that flows into the DC bus of the hydrogen storage DC microgrid.

[0027] Preferably, the current loop reference current control module of the DC-DC converter in the hydrogen storage device includes: a DC VSG control unit, a second state of charge monitoring unit, and a limiting control unit;

[0028] When the battery state of charge meets When the second state of charge monitoring unit outputs a current signal of 0 to the DC VSG control unit, the battery state of charge meets the or When the current signal output by the second state of charge monitoring unit to the DC VSG control unit is the set battery current reference value;

[0029] The DC VSG control unit uses the sum of the current reference value of the hydrogen storage DC microgrid flowing into the DC bus and the current signal output by the second state of charge monitoring unit as the input current signal; obtains the transfer function based on the optimized mechanical equation of the synchronous generator rotor, uses the input current signal, the current flowing into the electrolyzer by the DC bus, and the current flowing into the DC bus by the fuel cell, obtains the voltage signal based on the transfer function, and determines the steady-state current reference value of hydrogen storage when the hydrogen storage DC microgrid reaches steady-state operation according to the difference between the actual voltage of the DC bus and the voltage reference value and the difference between the voltage signal;

[0030] The limiting control unit includes a slope limiter, a first limiter and a second limiter; when the steady-state current reference value of the hydrogen storage device is positive, the difference between the current signal obtained after the current reference value of the hydrogen storage device passes through the slope limiter and the first limiter and the output current of the fuel cell is used as the current loop reference current control module to provide the current reference value of the DC-DC converter of the fuel cell; when the steady-state current reference value of the hydrogen storage device is negative, the difference between the current signal obtained after the current reference value of the hydrogen storage device passes through the second limiter and the input current of the electrolyzer is used as the current loop reference current control module to provide the current reference value of the DC-DC converter of the electrolyzer.

[0031] Preferably, the transfer function is obtained based on optimizing the mechanical equation of the synchronous generator rotor, including:

[0032] The virtual inertia and virtual damping coefficient are introduced to optimize the mechanical equation of the synchronous generator rotor to satisfy the following relationship:

[0033] ,

[0034] In the formula, is the actual angular frequency of the power grid, is the grid reference angular frequency, is the mechanical power, is the electromagnetic power, is the virtual moment of inertia, is the virtual damping coefficient;

[0035] Will , , , The actual voltage of the DC bus is , DC bus voltage reference value , the current reference value of the hydrogen storage DC microgrid entering the DC bus , the current of the fuel cell entering the DC bus The current entering the electrolyzer with the DC bus The difference is replaced by the transfer function of the DC VSG control unit model, which satisfies the following relationship:

[0036] ,

[0037] In the formula, and They are the analog virtual moment of inertia in the DC VSG control unit and the virtual damping coefficient The resulting parameters.

[0038] Preferably, the parameters of the current loop reference current control module of the DC-DC converter in the power storage device include: the parameters of the voltage regulator , the proportionality coefficient between the battery output voltage and the actual voltage of the DC bus , Strategy coefficient of dynamic shutdown unit .

[0039] Preferably, the parameters of the current loop reference current control module of the DC-DC converter in the hydrogen storage device include: the analog virtual moment of inertia in the DC VSG control unit Parameters , analog virtual damping coefficient in DC VSG control unit Parameters , the change rate of the actual current of the hydrogen storage DC microgrid entering the DC bus .

[0040] Preferably, the indicators of coordinated control include: the rated output power of the battery and the fluctuation range of the DC bus voltage, the smoothness of the battery output current and the battery service life, and the moment of inertia in the mechanical equation of the synchronous generator rotor.

[0041] The present invention also proposes a VSG collaborative control device for a hydrogen storage DC microgrid, comprising:

[0042] The current loop reference current control module of the DC-DC converter in the power storage device is used to take the actual voltage and voltage reference value of the DC bus, the actual current and current reference value of the hydrogen storage DC microgrid into the DC bus as input data. When the current loop reference current control module provides the current reference value to the current loop of the DC-DC converter in the power storage device, the current reference value is the difference between the battery steady-state current reference value and the battery output current when the hydrogen storage DC microgrid reaches steady-state operation; when the battery charge state meets or When the current loop reference current control module provides a current reference value to the current loop of the DC-DC converter in the power storage device, which is the difference between the set battery current reference value and the battery output current;

[0043] The current loop reference current control module of the DC-DC converter in the hydrogen storage device is used to take the set battery current reference value, the current reference value of the hydrogen storage DC microgrid entering the DC bus, the current entering the electrolyzer from the DC bus, and the current entering the DC bus from the fuel cell as input data. When the battery charge state meets The current loop reference current control module processes the input data based on the synchronous generator rotor mechanical equation to determine the steady-state current reference value of the hydrogen storage when the hydrogen storage DC microgrid reaches steady-state operation. or When the current loop reference current control module processes the input data and the set battery current reference value based on the synchronous generator rotor mechanical equation to determine the hydrogen storage steady-state current reference value when the hydrogen storage DC microgrid reaches steady-state operation; when the hydrogen storage steady-state current reference value When the hydrogen storage steady-state current reference value is positive, the current loop reference current control module determines the current reference value provided by the current loop reference current control module to the current loop of the DC-DC converter of the fuel cell by using the hydrogen storage steady-state current reference value and the fuel cell output current; when the hydrogen storage steady-state current reference value is negative, the current loop reference current control module determines the current reference value provided by the current loop reference current control module to the current loop of the DC-DC converter of the electrolyzer by using the hydrogen storage steady-state current reference value and the electrolyzer input current;

[0044] in, is the state of charge of the battery, is the upper limit of the state of charge, It is the lower limit of the charge state;

[0045] The current loop reference current control module parameter setting module is used to form state variables based on the voltage difference between the actual voltage of the DC bus and the voltage reference value, the current difference between the actual current of the hydrogen storage DC microgrid entering the DC bus and the current reference value, and the current of the battery entering the DC bus; based on the state space equation, using the state variables, with the goal of optimizing various indicators of collaborative control, the parameters of the current loop reference current control module of the DC-DC converter in the electricity storage device and the current loop reference current control module of the DC-DC converter in the hydrogen storage device are set; with the set current loop reference current control module of the DC-DC converter in the electricity storage device and the current loop reference current control module of the DC-DC converter in the hydrogen storage device, VSG collaborative control of the hydrogen storage DC microgrid is carried out.

[0046] Preferably, the current loop reference current control module of the DC-DC converter in the power storage device includes: a voltage speed regulator, a dynamic shutdown unit, and a first state of charge monitoring unit;

[0047] The voltage regulator provides a first current signal to the first state of charge monitoring unit according to the difference between the actual voltage of the DC bus and the voltage reference value;

[0048] The dynamic shutdown unit uses the difference between the current reference value of the hydrogen-containing DC storage microgrid entering the DC bus and the actual current of the hydrogen-containing DC storage microgrid entering the DC bus as the second current signal of the first charge state monitoring unit;

[0049] The first state of charge monitoring unit determines the steady-state current reference value of the battery when the hydrogen storage DC microgrid reaches steady-state operation according to the inverse of the sum of the first current signal and the second current signal. At the same time, the first state of charge monitoring unit obtains the set battery current reference value. When the battery state of charge meets When the state of charge of the battery meets the condition, the current reference value provided by the first state of charge monitoring unit to the current loop is the difference between the steady-state current reference value of the battery and the output current of the battery; when the state of charge of the battery meets the condition or When the current loop reference current control module provides the current reference value to the current loop, the current reference value is the difference between the set battery current reference value and the battery output current.

[0050] Preferably, the current loop reference current control module of the DC-DC converter in the hydrogen storage device includes: a DC VSG control unit, a second state of charge monitoring unit, and a limiting control unit;

[0051] When the battery state of charge meets When the second state of charge monitoring unit outputs a current signal of 0 to the DC VSG control unit, the battery state of charge meets the or When the current signal output by the second state of charge monitoring unit to the DC VSG control unit is the set battery current reference value;

[0052] The DC VSG control unit uses the sum of the current reference value of the hydrogen storage DC microgrid flowing into the DC bus and the current signal output by the second state of charge monitoring unit as the input current signal; obtains the transfer function based on the optimized mechanical equation of the synchronous generator rotor, uses the input current signal, the current flowing into the electrolyzer by the DC bus, and the current flowing into the DC bus by the fuel cell, obtains the voltage signal based on the transfer function, and determines the steady-state current reference value of hydrogen storage when the hydrogen storage DC microgrid reaches steady-state operation according to the difference between the actual voltage of the DC bus and the voltage reference value and the difference between the voltage signal;

[0053] The limiting control unit includes a slope limiter, a first limiter and a second limiter; when the steady-state current reference value of the hydrogen storage device is positive, the difference between the current signal obtained after the current reference value of the hydrogen storage device passes through the slope limiter and the first limiter and the output current of the fuel cell is used as the current loop reference current control module to provide the current reference value of the DC-DC converter of the fuel cell; when the steady-state current reference value of the hydrogen storage device is negative, the difference between the current signal obtained after the current reference value of the hydrogen storage device passes through the second limiter and the input current of the electrolyzer is used as the current loop reference current control module to provide the current reference value of the DC-DC converter of the electrolyzer.

[0054] A terminal comprises a processor and a storage medium; the storage medium is used to store instructions; the processor is used to operate according to the instructions to execute the steps of the method.

[0055] A computer-readable storage medium stores a computer program, which implements the steps of the method when executed by a processor.

[0056] The beneficial effects of the present invention are that, compared with the prior art, at least a method for collaborative control of an electric-hydrogen hybrid energy storage system containing hydrogen storage and direct current VSG control is proposed for an isolated DC microgrid system. The hydrogen storage device adopts a DC VSG strategy, and introduces virtual inertia by simulating the mechanical equation of the synchronous generator rotor, which can provide inertial support for the DC microgrid and improve system stability. Considering the difference in response speed between the hydrogen storage device and the battery energy storage, the fast speed response characteristics of the battery energy storage are used to cope with system power fluctuations, and the battery adopts a speed regulator control method to improve the dynamic response capability of the system. At the same time, in order to enable the hydrogen storage device with higher energy density to bear the steady-state power shortage, a dynamic shutdown strategy for the battery is proposed, which can reduce the number of battery charge and discharge times, effectively extend the battery life, and reduce the system operation and maintenance costs. Different control strategies are adopted for different electric and hydrogen energy storage technologies to achieve collaborative control of the overall hybrid energy storage system.

[0057] By simulating the characteristics of synchronous generators, a hydrogen storage VSG control strategy is introduced to provide system voltage support and enhance system stability. The fast response speed of battery energy storage is used to cope with system power fluctuations and make up for the slow response speed of hydrogen energy storage. At the same time, in view of the low energy density of battery energy storage and the difficulty in providing a stable energy supply, a dynamic battery shutdown strategy is proposed, in which the hydrogen storage with higher energy density bears the steady-state power difference, reducing the number of battery charge and discharge times to extend its life.

[0058] In view of the randomness and uncertainty of distributed energy output, an electric-hydrogen hybrid energy storage system is proposed. The fast response speed of battery energy storage is used to smooth the power fluctuation of the system. At the same time, the introduction of hydrogen energy storage effectively solves the problem that battery energy storage is difficult to balance energy density and economic operation. In view of the problem that the battery is in a state of charge and discharge for a long time, which will shorten its life, a dynamic shutdown strategy for battery energy storage is proposed to reduce the number of battery charge and discharge times to increase the battery life. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 It is a block diagram of VSG collaborative control of a hydrogen storage DC microgrid of the present invention;

[0060] Figure 1 The reference numerals in the figures are described as follows:

[0061] 100-current loop reference current control module of DC-DC converter in electric storage device, 101-voltage speed regulator, 102-dynamic shutdown unit, 103-first state of charge monitoring unit, 200-current loop reference current control module of DC-DC converter in hydrogen storage device, 201-DC VSG control unit, 202-second state of charge monitoring unit, 203-limiting control unit, 213-slope limiter, 223-first limiter, 233-second limiter;

[0062] Figure 2 is a parameter in the embodiment of the present invention Fixed pair parameters DC bus voltage waveform during setting;

[0063] Figure 3 is a parameter in the embodiment of the present invention Fixed pair parameters DC bus voltage waveform during setting;

[0064] Figure 4 is a power simulation result of a hydrogen storage DC microgrid system when the control method proposed in the present invention is adopted in an embodiment of the present invention;

[0065] Figure 5 is the power simulation result of the hydrogen storage DC microgrid system when the traditional droop control method is adopted in the embodiment of the present invention;

[0066] Figure 6 It is the simulation result of the system bus voltage when the control method proposed by the present invention and the traditional droop control method are adopted in the embodiment of the present invention. DETAILED DESCRIPTION

[0067] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The embodiments described in this application are only embodiments of a part of the present invention, rather than all embodiments. Based on the spirit of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the protection scope of the present invention.

[0068] like Figure 1 As shown, the DC bus is connected to the wind turbine via an AC / DC converter, connected to the photovoltaic array via a DC / DC converter, connected to the charging pile via a DC / DC converter, and connected to the AC load via an AC / DC converter; the hydrogen storage DC microgrid includes batteries, electrolyzers, hydrogen storage tanks, and fuel cells. Figure 1 In the figure, the solid line with an arrow indicates the direction of power flow, the dotted line with an arrow indicates the direction of hydrogen flow, and the dashed line with an arrow indicates the current reference direction.

[0069] according to Figure 1 The current reference direction shown in the figure, the current of the hydrogen storage DC microgrid entering the DC bus, satisfies the following relationship:

[0070] (1)

[0071] In the formula, is the actual current of the hydrogen storage DC microgrid entering the DC bus, is the current that the battery sinks into the DC bus. is the current from the DC bus into the electrolytic cell, The current that the fuel cell sinks into the DC bus.

[0072] Figure 1 middle, is the battery output current, Input current to the electrolyzer, is the fuel cell output current, and PI represents the current loop in the controller of the DC-DC converter.

[0073] The present invention proposes a VSG coordinated control method for a hydrogen-containing DC storage microgrid, wherein the hydrogen-containing DC storage microgrid includes an electric storage device and a hydrogen storage device, wherein the electric storage device includes a DC-DC converter and a battery, and the hydrogen storage device includes an electrolyzer and its corresponding DC-DC converter, a hydrogen storage tank, a fuel cell and its corresponding DC-DC converter; the controller of each DC-DC converter includes a current loop; the coordinated control method includes:

[0074] Step 1: Establish a current loop reference current control module for the DC-DC converter in the power storage device; the current loop reference current control module uses the actual voltage and voltage reference value of the DC bus, the actual current and current reference value of the hydrogen storage DC microgrid entering the DC bus as input data, and when the battery charge state meets When the current loop reference current control module provides the current loop with a current reference value of the battery steady-state current reference value when the hydrogen storage DC microgrid reaches steady-state operation. With battery output current When the battery state of charge meets or When the current loop reference current control module provides the current loop with the current reference value set as the battery current reference value. With battery output current The difference between is the state of charge of the battery, is the upper limit of the state of charge, It is the lower limit of the charge state.

[0075] like Figure 1 As shown, the current loop reference current control module 100 of the DC-DC converter in the power storage device includes: a voltage speed regulator 101, a dynamic shutdown unit 102, and a first state of charge monitoring unit 103;

[0076] Specifically, Figure 1 As shown, the voltage regulator is based on the actual voltage of the DC bus. With voltage reference The difference between the current and the charge state monitoring unit is provided with a first current signal ;

[0077] In the embodiment, the voltage regulator uses the actual voltage of the DC bus With voltage reference The voltage difference As the input signal, the first current signal is obtained by the following relationship:

[0078] (2)

[0079] In the formula, is the first current signal, It is the parameter of voltage regulator.

[0080] Specifically, Figure 1 As shown, the dynamic shutdown unit uses the current reference value of the hydrogen storage DC microgrid entering the DC bus The actual current of the hydrogen storage DC microgrid entering the DC bus The difference between the two is used as the second current signal of the first state of charge monitoring unit. ;

[0081] In the embodiment, the dynamic shutdown unit uses the current reference value of the hydrogen storage DC microgrid entering the DC bus The actual current of the hydrogen storage DC microgrid entering the DC bus The current difference is the second current signal, satisfying the following relationship:

[0082] (3)

[0083] In addition, the current reference value of the DC bus of the hydrogen storage DC microgrid in the dynamic shutdown unit is The current difference Satisfies the following relationship:

[0084] (4)

[0085] In the formula, is the strategy coefficient of the dynamic shutdown unit.

[0086] Specifically, Figure 1 As shown, the first state of charge monitoring unit determines the battery steady-state current reference value when the hydrogen storage DC microgrid reaches steady-state operation according to the inverse of the sum of the first current signal and the second current signal. At the same time, the first state of charge monitoring unit obtains the set battery current reference value ; When the battery's state of charge meets When the first state of charge monitoring unit provides a current reference value to the current loop, the battery steady-state current reference value With battery output current When the battery state of charge meets or When the current loop reference current control module provides the current loop with the current reference value set as the battery current reference value. With battery output current The difference between

[0087] In the embodiment, in combination with equations (2) to (4), when the hydrogen storage DC microgrid reaches steady-state operation, the steady-state current reference value of the battery satisfies the following relationship:

[0088] (5)

[0089] In the formula, is the reference value of the battery steady-state current, The battery output voltage and the actual voltage of the DC bus The proportionality coefficient between is the actual voltage of the DC bus With voltage reference The voltage difference, is the current reference value of the hydrogen storage DC microgrid entering the DC bus, It is the actual current that flows into the DC bus of the hydrogen storage DC microgrid.

[0090] In the embodiment, when the actual state of charge of the battery does not reach the upper limit of the state of charge and charge state lower limit When At this time, the system has power shortage or surplus. Considering the slow response speed of the hydrogen storage device, most of the system power shortage or surplus can only be filled by the battery, that is, the steady-state current reference value of the battery Reaching the maximum and gradually decreasing, after the hydrogen storage device is fully started, the system power shortage or surplus is completely filled by the hydrogen storage device. At this time, the battery steady-state current reference value =0. According to formula (4), when the hydrogen storage DC microgrid reaches steady-state operation, the current reference value of the hydrogen storage DC microgrid entering the DC bus remains unchanged, then the current difference is 0, when When the battery steady-state current reference value is Reach the maximum and gradually decrease to 0, while the battery output current It also gradually decreases to 0, thereby realizing the dynamic shutdown of the battery output current.

[0091] The first current reference value provided by the current loop reference current control module of the DC-DC converter in the power storage device to the current loop satisfies the following relationship:

[0092] (6)

[0093] When the actual state of charge of the battery reaches the upper or lower limit of the state of charge, or In order to reduce the depth of battery charge and discharge and ensure the battery life, the battery current reference value is set at this time. The battery is charged and discharged at a constant current to return its SOC to the normal operating range. The second current reference value provided to the current loop by the current loop reference current control module of the DC-DC converter in the power storage device satisfies the following relationship:

[0094] (7)

[0095] The current loop reference current control module of the DC-DC converter in the electric storage device proposed in the present invention can use the voltage speed regulation outer loop and the dynamic shutdown strategy to provide reference current for the current loop before the battery SOC reaches the upper and lower limits, and provide reference current for the current loop according to the set battery current reference value after the battery SOC reaches the upper and lower limits. Among them, the voltage speed regulator control adjusts the size of the battery output power according to the system bus voltage deviation, and makes full use of the dynamic response characteristics of the battery output current that can quickly track the reference value to cope with system power fluctuations, thereby improving the response speed of the hydrogen storage device and accelerating the adjustment process of the hydrogen storage device. At the same time, the use of the dynamic shutdown strategy of the battery can ensure that the battery does not work under steady-state conditions, reduce the number of battery charge and discharge times, and effectively extend the battery life.

[0096] Step 2, establish a current loop reference current control module for the DC-DC converter in the hydrogen storage device; the current loop reference current control module for the DC-DC converter in the hydrogen storage device takes the set battery current reference value, the current reference value of the hydrogen storage DC microgrid entering the DC bus, the current of the DC bus entering the electrolyzer, and the current of the fuel cell entering the DC bus as input data. When the battery charge state meets hour,

[0097] The current loop reference current control module 200 of the DC-DC converter in the hydrogen storage device includes: a DC VSG control unit 201 , a second state of charge monitoring unit 202 , and a limit control unit 203 .

[0098] Specifically, Figure 1 As shown, when the battery state of charge meets When the second state of charge monitoring unit outputs a current signal of 0 to the DC VSG control unit, the hydrogen storage device does not need to charge or discharge the battery. When the state of charge of the battery meets or When the second state of charge monitoring unit outputs a current signal to the DC VSG control unit, the current signal is the set battery current reference value. At this time, the charging and discharging current of the battery is provided by the hydrogen storage device.

[0099] Specifically, Figure 1 As shown, the DC VSG control unit uses the current reference value of the hydrogen storage DC microgrid entering the DC bus The sum of the current signal output by the second state of charge monitoring unit is the input current signal; based on the optimization of the synchronous generator rotor mechanical equation, the transfer function is obtained, and the input current signal and the current of the DC bus entering the electrolyzer are used. , and the current that the fuel cell sinks into the DC bus Based on the transfer function, the voltage signal is obtained, and the steady-state current reference value of the hydrogen storage when the hydrogen storage DC microgrid reaches steady-state operation is determined according to the difference between the actual voltage of the DC bus and the voltage reference value and the difference between the voltage signal. ;

[0100] Based on the synchronous generator rotor mechanical equation, the DC VSG control unit model is established, including:

[0101] The mechanical equation of the synchronous generator rotor satisfies the following relationship:

[0102] (8)

[0103] In the formula, is the rotor moment of inertia, is the rotor damping coefficient, is the rotor angular velocity, is the synchronous angular velocity, is the mechanical torque, is the electromagnetic torque.

[0104] The virtual inertia and virtual damping coefficient are introduced to optimize the mechanical equation of the synchronous generator rotor to satisfy the following relationship:

[0105] (9)

[0106] In the formula, is the actual angular frequency of the power grid, is the grid reference angular frequency, is the mechanical power, is the electromagnetic power, is the virtual moment of inertia, is the virtual damping coefficient.

[0107] Will , , , Use , , , Instead, the transfer function of the DC VSG control unit model is obtained, which satisfies the following relationship:

[0108] (10)

[0109] In the formula, and They are the analog virtual moment of inertia in the DC VSG control unit and the virtual damping coefficient The obtained parameters, is the current reference value of the hydrogen storage DC microgrid entering the DC bus, is the current from the DC bus into the electrolytic cell, The current that flows into the DC bus for the fuel cell;

[0110] In the present invention, the hydrogen storage device adopts a DC VSG control strategy by simulating the characteristics of a synchronous generator, which can not only maintain the bus voltage stability, but also provide a certain inertia for the system and improve the system stability. If the load change time is too short when the fuel cell stack is working, it will cause the battery voltage to drop. When the pressure of the hydrogen storage tank is too low, it will cause the voltage reversal phenomenon, causing irreversible damage to the internal catalyst layer of the fuel cell and affecting the performance of the fuel cell. In order to improve the power generation safety of the fuel cell and make the fuel cell output smoother, a slope limiter can be added after the current reference signal to reduce the dynamic response speed of the fuel cell.

[0111] Specifically, Figure 1 As shown, the limit control unit includes a slope limiter 213, a first limiter 223 and a second limiter 233; wherein,

[0112] When the steady-state current reference value of hydrogen storage When it is positive, the current reference value of the hydrogen storage device The current signal obtained after the slope limiter and the first limiter is consistent with the fuel cell output current The difference between the current loop reference value and the current loop reference value provided by the current loop reference current control module to the current loop of the DC-DC converter of the fuel cell;

[0113] When the steady-state current reference value of hydrogen storage When it is negative, the current reference value of the hydrogen storage device The current signal obtained after the second limiter is consistent with the electrolytic cell input current The difference is used as the current reference value provided by the current loop reference current control module to the current loop of the DC-DC converter of the electrolyzer.

[0114] Step 3: Take the actual voltage of the DC bus With voltage reference The voltage difference , Current reference value of hydrogen storage DC microgrid The current of the DC bus that is connected to the hydrogen storage DC microgrid The current difference , the current of the battery into the DC bus Constitute state variables;

[0115] Based on the state space equation, with the goal of optimizing various indicators of coordinated control, the parameters of the current loop reference current control module of the DC-DC converter in the electricity storage device and the current loop reference current control module of the DC-DC converter in the hydrogen storage device are adjusted;

[0116] The VSG coordinated control of the hydrogen storage DC microgrid is carried out by using the adjusted current loop reference current control module of the DC-DC converter in the electricity storage device and the current loop reference current control module of the DC-DC converter in the hydrogen storage device.

[0117] The parameters of the current loop reference current control module of the DC-DC converter in the power storage device include: , the proportionality coefficient between the battery output voltage and the actual voltage of the DC bus , Strategy coefficient of dynamic shutdown unit ;

[0118] The parameters of the current loop reference current control module of the DC-DC converter in the hydrogen storage device include: the analog virtual moment of inertia in the DC VSG control unit Parameters , analog virtual damping coefficient in DC VSG control unit Parameters , the change rate of the actual current of the hydrogen storage DC microgrid entering the DC bus .

[0119] The control model parameters of the hybrid energy storage system are analyzed by constructing state space equations.

[0120] Specifically, by combining equation (1), equation (3) and equation (10), we get the following relationship:

[0121] (11)

[0122] Combining equation (1) and equation (4), we get the following relationship:

[0123] (12)

[0124] In the formula, is the rate of change of the current entering the DC bus of the hydrogen storage DC microgrid, satisfying the following relationship:

[0125] (13)

[0126] The response speed of the current loop of the DC-DC converter in the power storage device is in the millisecond level, so the battery output current can quickly track the current reference value to meet .

[0127] Then from formula (5) we can get

[0128] (14)

[0129] Combining equations (11), (12) and (14), we get the following relationship:

[0130] (15)

[0131] Defining state variables , based on the state-space equation , according to formula (11), formula (12) and formula (15), we get the following relationship:

[0132] (16)

[0133] is the parameter matrix, is the perturbation vector, is the state space;

[0134] From formula (16), we can get the matrix The characteristic value of ,0, ,when , , , When are all positive, the corresponding characteristic roots of the state space equation are all located in the left half of the complex plane or on the imaginary axis, and the system can reach a steady state. As it approaches infinity, the system disturbance term is equal to 0, is equal to 0, so is equal to 0, and =0, that is, the bus voltage is maintained near the reference value, and the battery is dynamically shut down. Combining formula (16), we can get The current flowing into the DC bus is composed of the fuel cell current and the electrolyzer current, that is, the system power shortage is provided by the hydrogen storage device.

[0135] By comparing the control effects under different control parameters and taking the optimization of various indicators of coordinated control as the goal, the parameters of the current loop reference current control module of the DC-DC converter in the electricity storage device and the current loop reference current control module of the DC-DC converter in the hydrogen storage device are adjusted to realize the coordinated control of hybrid energy storage.

[0136] The indicators of coordinated control include: battery rated output power and DC bus voltage fluctuation range, battery output current smoothness and battery service life, and moment of inertia in the synchronous generator rotor mechanical equation.

[0137] Specifically, considering the dynamic response speed of the system, the smaller the negative characteristic root, the faster the attenuation speed. However, if the characteristic root difference is too large, it will lead to significant differences in the response speed of the system in different modes, affecting the overall performance. To make the battery current output change more smoothly and avoid overcharging or overdischarging of the battery that affects its service life, select is 5. Considering the rotational inertia of the traditional synchronous generator rotor mechanical equation, we select The range of variation is 0.1 to 5.0.

[0138] exist Fixed and Under different values, the DC bus voltage waveform is as follows: Figure 2 As shown. When 2.0 and 5.0 are used, the system takes a shorter time to reach steady state; when When the value is 0.1, the bus voltage rises to 801V, and the system takes a long time to reach steady state. To make the two characteristic roots close in value, select is 2.0.

[0139] Similarly, select The range is 1.0 to 10.0. Fixed and Under different values, the system DC bus voltage waveform is as follows: Figure 3 As shown, When the value is 5.0, the time required for the system to reach steady state is shorter.

[0140] According to the set control model parameters of the hybrid energy storage system, the simulation and comparison with the droop control strategy are carried out in the simulation model of the isolated DC microgrid system. The simulation model includes wind turbines, photovoltaics, electric hydrogen hybrid energy storage systems, charging piles and AC loads, among which the charging piles and AC loads adopt constant power models with rated powers of 82kW and 25kW respectively. In order to simulate the volatility of wind turbine and photovoltaic output power, Gaussian random numbers are added on the basis of the given values ​​of wind speed and light intensity. At the same time, in order to observe the fluctuation of the system bus under different working conditions, the wind speed is controlled in different time periods to simulate the situation where the distributed energy output is greater than or less than the system load power demand. The specific settings are: the initial wind speed is 6m / s, the wind speed increases to 8.5m / s at 2.5s, and the wind speed decreases to 4m / s at 6s. The bus voltage reference value is 800V.

[0141] Figure 4The power simulation results of the hydrogen storage DC microgrid system using the control method proposed in the present invention are shown. When the system is initially running, the output of distributed energy cannot meet the load demand. At this time, the battery provides the main power, and the fuel cell starts slowly, gradually takes on the main power, and the battery power gradually decreases to 0. When the system has surplus power, the battery is limited to absorb power, and the fuel cell starts slowly and absorbs power. After it is fully turned on, the battery power absorption power is 0, realizing dynamic shutdown.

[0142] Figure 5 The power simulation results of the hybrid energy storage system when the traditional droop control method is used. The control of the electric-hydrogen hybrid energy storage converter adopts droop control. At the same time, in order to reduce the bus voltage deviation, the bus voltage secondary regulation integral term is added before the droop control. The set droop control coefficient is 0.1, and the secondary regulation integral coefficient is 0.1. If the droop control strategy is adopted, there may be a situation where the fuel cell and the electrolyzer switch to work, and the battery is always in working state and cannot be shut down.

[0143] Figure 6 The simulation results of the system bus voltage when the control method proposed in the present invention and the traditional droop control method are adopted. When the droop control strategy is adopted at 2.5s, the bus voltage rises to 869.6V; when the VSG control strategy is adopted, the bus voltage rises to 823.2V, and the overshoot is reduced by 5.8%. When the droop control strategy is adopted at 6s, the bus voltage drops to 688.5V; when the VSG control strategy is adopted, the bus voltage drops to 751.5V, and the drop is reduced by 7.87%. Compared with the droop control, the strategy proposed in the present invention can effectively reduce the overshoot of the DC bus voltage and ensure the stability of the system.

[0144] The present disclosure may be a system, a method and / or a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present disclosure.

[0145] A computer-readable storage medium may be a tangible device that can hold and store instructions used by an instruction execution device. A computer-readable storage medium may be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the above. More specific examples (a non-exhaustive list) of computer-readable storage media include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disk read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device, such as a punch card or a raised structure in a groove on which instructions are stored, and any suitable combination of the above. The computer-readable storage medium used herein is not to be interpreted as a transient signal itself, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., a light pulse through a fiber optic cable), or an electrical signal transmitted through a wire.

[0146] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to each computing / processing device, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network can include copper transmission cables, optical fiber transmissions, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in the computer-readable storage medium in each computing / processing device.

[0147] The computer program instructions for performing the operations of the present disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages, such as Smalltalk, C++, etc., and conventional procedural programming languages, such as "C" language or similar programming languages. The computer-readable program instructions may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer, partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., using an Internet service provider to connect through the Internet). In some embodiments, by using the state information of the computer-readable program instructions to personalize an electronic circuit, such as a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA), the electronic circuit may execute the computer-readable program instructions, thereby implementing various aspects of the present disclosure.

[0148] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A VSG collaborative control method for a hydrogen storage DC microgrid, wherein the hydrogen storage DC microgrid includes an electric storage device and a hydrogen storage system, wherein: The electric storage device includes a DC-DC converter and a battery, and the hydrogen storage device includes an electrolyzer and its corresponding DC-DC converter, a hydrogen storage tank, a fuel cell and its corresponding DC-DC converter; the controller of each DC-DC converter includes a current loop; and is characterized in that it includes: The current loop reference current control module of the DC-DC converter in the electric storage device takes the actual voltage and voltage reference value of the DC bus, the actual current and current reference value of the DC bus as input, and generates the current reference value of the DC-DC converter in the electric storage device, including: When , the current reference value is the difference between the battery steady-state current reference value and the battery output current; or When , the current reference value is the difference between the set battery current reference value and the battery output current; The current loop reference current control module of the DC-DC converter in the hydrogen storage device takes the set battery current reference value, the DC bus current reference value, the current of the DC bus entering the electrolyzer, and the current of the fuel cell entering the DC bus as inputs, and includes: When the input data is used based on the synchronous generator rotor mechanical equation to determine the steady-state current reference value of the hydrogen storage, or When the hydrogen storage steady-state current reference value is positive, the hydrogen storage steady-state current reference value and the fuel cell output current are used to determine the current reference value of the DC-DC converter of the fuel cell; when the hydrogen storage steady-state current reference value is negative, the hydrogen storage steady-state current reference value and the electrolyzer input current are used to determine the current reference value of the DC-DC converter of the electrolyzer; is the battery charge state, is the upper limit of the state of charge, It is the lower limit of the charge state; The state variables are composed of the voltage difference between the actual voltage of the DC bus and the voltage reference value, the current difference between the actual current of the DC bus and the current reference value, and the current of the battery entering the DC bus. Based on the state space equation, the collaborative control index is optimal. After the parameters of the current loop reference current control modules of the DC-DC converter in the electric storage device and the DC-DC converter in the hydrogen storage device are adjusted, VSG collaborative control of the hydrogen storage DC microgrid is carried out.

2. The VSG collaborative control method of the hydrogen storage DC microgrid according to claim 1 is characterized in that: A current loop reference current control module of a DC-DC converter in an electric storage device, comprising: a voltage speed regulator, a dynamic shutdown unit, and a first state of charge monitoring unit; The voltage regulator provides a first current signal to the first state of charge monitoring unit according to the difference between the actual voltage of the DC bus and the voltage reference value; The dynamic shutdown unit uses the difference between the current reference value of the hydrogen-containing DC storage microgrid entering the DC bus and the actual current of the hydrogen-containing DC storage microgrid entering the DC bus as the second current signal of the first charge state monitoring unit; The first state of charge monitoring unit determines the steady-state current reference value of the battery when the hydrogen storage DC microgrid reaches steady-state operation according to the inverse of the sum of the first current signal and the second current signal. At the same time, the first state of charge monitoring unit obtains the set battery current reference value. When the battery state of charge meets When the state of charge of the battery meets the condition, the current reference value provided by the first state of charge monitoring unit to the current loop is the difference between the steady-state current reference value of the battery and the output current of the battery; when the state of charge of the battery meets the condition or When the current loop reference current control module provides the current reference value to the current loop, the current reference value is the difference between the set battery current reference value and the battery output current.

3. The VSG collaborative control method of the hydrogen storage DC microgrid according to claim 2 is characterized in that: The voltage regulator uses the actual voltage of the DC bus With voltage reference The voltage difference is the input signal, and the first current signal is obtained by the following relationship: ， In the formula, is the first current signal, It is the parameter of voltage regulator.

4. The VSG collaborative control method of the hydrogen storage DC microgrid according to claim 3 is characterized in that: The dynamic shutdown unit uses the current difference between the current reference value of the hydrogen storage DC microgrid entering the DC bus and the actual current of the hydrogen storage DC microgrid entering the DC bus as the output signal, satisfying the following relationship: ， In the formula, is the second current signal, is the current reference value of the hydrogen storage DC microgrid entering the DC bus, The current that flows into the DC bus of the hydrogen storage DC microgrid; In addition, the current reference value and the current difference of the hydrogen storage DC microgrid entering the DC bus in the dynamic shutdown unit satisfy the following relationship: ， In the formula, is the strategy coefficient of the dynamic shutdown unit.

5. The VSG collaborative control method of the hydrogen storage DC microgrid according to claim 4 is characterized in that: When the hydrogen storage DC microgrid reaches steady-state operation, the steady-state current reference value of the battery satisfies the following relationship: ， In the formula, is the reference value of the battery steady-state current, The battery output voltage and the actual voltage of the DC bus The proportionality coefficient between is the actual voltage of the DC bus With voltage reference The voltage difference, is the current reference value of the hydrogen storage DC microgrid entering the DC bus, It is the actual current that flows into the DC bus of the hydrogen storage DC microgrid.

6. The VSG collaborative control method of the hydrogen storage DC microgrid according to claim 1 is characterized in that: The current loop reference current control module of the DC-DC converter in the hydrogen storage device includes: a DC VSG control unit, a second state of charge monitoring unit, and a limit control unit; When the battery state of charge meets When the second state of charge monitoring unit outputs a current signal of 0 to the DC VSG control unit, the battery state of charge meets the or When the current signal output by the second state of charge monitoring unit to the DC VSG control unit is the set battery current reference value; The DC VSG control unit uses the sum of the current reference value of the hydrogen storage DC microgrid flowing into the DC bus and the current signal output by the second state of charge monitoring unit as the input current signal; obtains the transfer function based on the optimized mechanical equation of the synchronous generator rotor, uses the input current signal, the current flowing into the electrolyzer by the DC bus, and the current flowing into the DC bus by the fuel cell, obtains the voltage signal based on the transfer function, and determines the steady-state current reference value of hydrogen storage when the hydrogen storage DC microgrid reaches steady-state operation according to the difference between the actual voltage of the DC bus and the voltage reference value and the difference between the voltage signal; The limiting control unit includes a slope limiter, a first limiter and a second limiter; when the steady-state current reference value of the hydrogen storage device is positive, the difference between the current signal obtained after the current reference value of the hydrogen storage device passes through the slope limiter and the first limiter and the output current of the fuel cell is used as the current loop reference current control module to provide the current reference value of the DC-DC converter of the fuel cell; when the steady-state current reference value of the hydrogen storage device is negative, the difference between the current signal obtained after the current reference value of the hydrogen storage device passes through the second limiter and the input current of the electrolyzer is used as the current loop reference current control module to provide the current reference value of the DC-DC converter of the electrolyzer.

7. The VSG coordinated control method of the hydrogen storage DC microgrid according to claim 6 is characterized in that: The transfer function is obtained based on the optimization of the synchronous generator rotor mechanical equation, including: The virtual inertia and virtual damping coefficient are introduced to optimize the mechanical equation of the synchronous generator rotor to satisfy the following relationship: ， In the formula, is the actual angular frequency of the power grid, is the grid reference angular frequency, is the mechanical power, is the electromagnetic power, is the virtual moment of inertia, is the virtual damping coefficient; Will , , , The actual voltage of the DC bus is , DC bus voltage reference value , the current reference value of the hydrogen storage DC microgrid entering the DC bus , the current of the fuel cell entering the DC bus The current entering the electrolyzer with the DC bus The difference is replaced by the transfer function of the DC VSG control unit model, which satisfies the following relationship: ， In the formula, and They are the analog virtual moment of inertia in the DC VSG control unit and the virtual damping coefficient The resulting parameters.

8. The VSG coordinated control method of the hydrogen storage DC microgrid according to claim 5 is characterized in that: The parameters of the current loop reference current control module of the DC-DC converter in the power storage device include: the parameters of the voltage regulator , the proportionality coefficient between the battery output voltage and the actual voltage of the DC bus , Strategy coefficient of dynamic shutdown unit .

9. The VSG coordinated control method of the hydrogen storage DC microgrid according to claim 6 is characterized in that: The parameters of the current loop reference current control module of the DC-DC converter in the hydrogen storage device include: the analog virtual moment of inertia in the DC VSG control unit Parameters , analog virtual damping coefficient in DC VSG control unit Parameters , the change rate of the actual current of the hydrogen storage DC microgrid entering the DC bus .

10. The VSG coordinated control method of a hydrogen storage DC microgrid according to claim 1, characterized in that: The indicators of coordinated control include: battery rated output power and DC bus voltage fluctuation range, battery output current smoothness and battery service life, and moment of inertia in the synchronous generator rotor mechanical equation.

11. A VSG collaborative control device for a hydrogen storage DC microgrid using the method according to any one of claims 1 to 10, characterized in that: include: The current loop reference current control module of the DC-DC converter in the electric storage device is used to generate the current reference value of the DC-DC converter in the electric storage device by taking the actual voltage and voltage reference value of the DC bus, the actual current and current reference value of the DC bus as input, and includes: When the input data is used based on the synchronous generator rotor mechanical equation to determine the steady-state current reference value of the hydrogen storage, or When the hydrogen storage steady-state current reference value is positive, the hydrogen storage steady-state current reference value and the fuel cell output current are used to determine the current reference value of the DC-DC converter of the fuel cell; when the hydrogen storage steady-state current reference value is negative, the hydrogen storage steady-state current reference value and the electrolyzer input current are used to determine the current reference value of the DC-DC converter of the electrolyzer; is the battery charge state, is the upper limit of the state of charge, It is the lower limit of the charge state; The current loop reference current control module parameter setting module is used to form state variables based on the voltage difference between the actual voltage of the DC bus and the voltage reference value, the current difference between the actual current of the DC bus and the current reference value, and the current of the battery entering the DC bus; based on the state space equation, the collaborative control index is optimal, and after the parameters of the current loop reference current control modules of the DC-DC converter in the electric storage device and the DC-DC converter in the hydrogen storage device are set, VSG collaborative control of the hydrogen storage DC microgrid is carried out.

12. The VSG collaborative control device of the hydrogen storage DC microgrid according to claim 11, characterized in that: A current loop reference current control module of a DC-DC converter in an electric storage device, comprising: a voltage speed regulator, a dynamic shutdown unit, and a first state of charge monitoring unit; The voltage regulator provides a first current signal to the first state of charge monitoring unit according to the difference between the actual voltage of the DC bus and the voltage reference value; The dynamic shutdown unit uses the difference between the current reference value of the hydrogen-containing DC storage microgrid entering the DC bus and the actual current of the hydrogen-containing DC storage microgrid entering the DC bus as the second current signal of the first charge state monitoring unit; The first state of charge monitoring unit determines the steady-state current reference value of the battery when the hydrogen storage DC microgrid reaches steady-state operation according to the inverse of the sum of the first current signal and the second current signal. At the same time, the first state of charge monitoring unit obtains the set battery current reference value. When the battery state of charge meets When the state of charge of the battery meets the condition, the current reference value provided by the first state of charge monitoring unit to the current loop is the difference between the steady-state current reference value of the battery and the output current of the battery; when the state of charge of the battery meets the condition or When the current loop reference current control module provides the current reference value to the current loop, the current reference value is the difference between the set battery current reference value and the battery output current.

13. The VSG collaborative control device of the hydrogen storage DC microgrid according to claim 11, characterized in that: The current loop reference current control module of the DC-DC converter in the hydrogen storage device includes: a DC VSG control unit, a second state of charge monitoring unit, and a limit control unit; When the battery state of charge meets When the second state of charge monitoring unit outputs a current signal of 0 to the DC VSG control unit, the battery state of charge meets the or When the current signal output by the second state of charge monitoring unit to the DC VSG control unit is the set battery current reference value; The DC VSG control unit uses the sum of the current reference value of the hydrogen storage DC microgrid flowing into the DC bus and the current signal output by the second state of charge monitoring unit as the input current signal; obtains the transfer function based on the optimized mechanical equation of the synchronous generator rotor, uses the input current signal, the current flowing into the electrolyzer by the DC bus, and the current flowing into the DC bus by the fuel cell, obtains the voltage signal based on the transfer function, and determines the steady-state current reference value of hydrogen storage when the hydrogen storage DC microgrid reaches steady-state operation according to the difference between the actual voltage of the DC bus and the voltage reference value and the difference between the voltage signal; The limiting control unit includes a slope limiter, a first limiter and a second limiter; when the steady-state current reference value of the hydrogen storage device is positive, the difference between the current signal obtained after the current reference value of the hydrogen storage device passes through the slope limiter and the first limiter and the output current of the fuel cell is used as the current loop reference current control module to provide the current reference value of the DC-DC converter of the fuel cell; when the steady-state current reference value of the hydrogen storage device is negative, the difference between the current signal obtained after the current reference value of the hydrogen storage device passes through the second limiter and the input current of the electrolyzer is used as the current loop reference current control module to provide the current reference value of the DC-DC converter of the electrolyzer.

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