Method, system, device and storage medium for active participation of electrolytic hydrogen production converter in microgrid frequency regulation

Abstract

The present invention discloses a method, system, device and storage medium for an electrolytic hydrogen production inverter to actively participate in microgrid frequency regulation. Some existing methods do not take into account the power adjustability of the new energy hydrogen production system itself, resulting in the inability of the new energy hydrogen production system to effectively support the grid frequency, affecting the harmonious grid connection between the new energy hydrogen production system and the grid. The method for the electrolytic hydrogen production inverter to actively participate in microgrid frequency regulation adopted by the present invention is: real-time monitoring of the frequency change of the microgrid, determining the frequency deviation from the frequency change, and adjusting the output power of the electrolytic hydrogen production inverter through the primary frequency modulation mode of the active power active adjustment control strategy according to the size of the frequency deviation, so that the electrolytic hydrogen production inverter has inertia, damping and frequency modulation characteristics, thereby participating in the frequency regulation of the microgrid and realizing primary frequency regulation. The present invention can not only provide inertia damping support in the transient process, but also perform effective frequency regulation in the steady state.

Description

Technical Field

[0001] The present invention belongs to the technical field of microgrids in power systems, and relates to a method, system, device and storage medium for an electrolytic hydrogen production converter to actively participate in frequency regulation of a microgrid. Background Art

[0002] As an intelligent, flexible and renewable energy system, microgrid has received extensive attention and research. The core task of microgrid is to control the frequency to maintain the stability of the system.

[0003] Although traditional chemical methods have low costs for hydrogen production, they will produce a lot of carbon dioxide emissions, and most biomass hydrogen production technologies are still in the research stage. In contrast, the cost of water electrolysis is higher, but if it is combined with renewable energy to produce hydrogen, it can not only reduce electricity costs, but also achieve zero carbon emissions from the entire process from hydrogen production to use.

[0004] A standard new energy water electrolysis hydrogen production system usually includes a new energy power generation device, a hydrogen production device and a hydrogen storage device, all of which are connected to the AC power grid through a converter. The new energy hydrogen production system is connected to the power grid through a converter. Due to the lack of rotating parts like synchronous generators, it cannot provide inertia support for the power grid under traditional control strategies, and its ability to actively participate in grid regulation is weak. Its large-scale grid connection is not conducive to the safe and stable operation of the power system. Electric hydrogen production can be used as a controllable load, which shows great potential in reducing new energy power fluctuations and participating in grid regulation. Therefore, the regulation capability of the new energy hydrogen production system can be utilized by improving the control strategy, thereby achieving frequency regulation to ensure the safe and stable operation of the system.

[0005] In the paper “Energy Management of Hydrogen-Photovoltaic Combined Power Supply System”, Xu Min et al. combined photovoltaic, fuel cell and electrolyzer, and proposed an energy management control strategy for hydrogen-photovoltaic combined power supply system based on dual Buck converter, which improved the utilization rate of solar cell output power. In the paper “Grid-connected Control Strategy of Photovoltaic Hydrogen Storage”, Peng Long et al. combined photovoltaic, electrolyzer, fuel cell and supercapacitor on DC bus, and proposed a power coordination control strategy for photovoltaic-hydrogen hybrid power generation system. In the paper “Frequency regulation possibilities of power-to-gasplants in grids including high shares of renewable energy production”, Peltoniemi P et al. pointed out that electrolytic hydrogen production plant has the ability to provide auxiliary services for power system frequency regulation, and studied the frequency regulation behavior of 9MW power level electrolyzer under different power change rates. In the paper “Online Energy Regulation Strategy and Experimental Platform Construction of Wind-Photovoltaic-Hydrogen Integrated Energy System”, Kong Lingguo et al. adopted a hierarchical communication method, calculated the power command value based on the current operating status of the system and the online energy regulation strategy, and sent it to the converter to adjust the hydrogen production power, realizing three-stage frequency regulation. Cai Guowei et al. constructed a hybrid system structure including wind power, photovoltaic, electrolyzer and supercapacitor in the document "Modeling and Control of Wind Power / Photovoltaic / Hydrogen Production / Supercapacitor Grid-connected System", and proposed a control strategy for wind power / photovoltaic / hydrogen production / supercapacitor grid-connected system for four operating conditions of the system, achieving grid-connected power smoothing and DC voltage stability. Torreglosa JP et al. proposed a coordinated control strategy for the electric-hydrogen coupling system based on model predictive control in the document "Energy dispatching based on predictive controller of an off-grid windturbine / photovoltaic / hydrogen / battery hybrid system" to optimize the power balance of the system. Although existing research has reduced the power fluctuations of new energy when it is connected to the grid to a certain extent by coordinating and controlling the new energy hydrogen production system, these methods are not perfect enough and cannot effectively support the grid frequency, which affects their harmonious connection with the grid. Summary of the invention

[0006] In order to improve the grid-connected characteristics of a new energy power generation system connected to the grid through a converter, the present invention proposes a method, system, device and storage medium for an electrolytic hydrogen production converter to actively participate in microgrid frequency regulation, which adopts an active power regulation (APR) control strategy. Through this strategy, the converter has inertia, damping and frequency modulation characteristics, thereby improving the stability of the system.

[0007] In a first aspect, the present invention provides a method for an electrolytic hydrogen production converter to actively participate in frequency regulation of a microgrid, which monitors the frequency change of the microgrid in real time, determines the frequency deviation from the frequency change, and adjusts the output power of the electrolytic hydrogen production converter through a primary frequency regulation mode of an active power active regulation control strategy according to the magnitude of the frequency deviation, so that the electrolytic hydrogen production converter has inertia, damping and frequency regulation characteristics, thereby participating in the frequency regulation of the microgrid and realizing primary frequency regulation;

[0008] Among them, the primary frequency modulation mode of the active power active regulation control strategy is: when the load in the microgrid fluctuates, the difference between the active power set value and the actual active power of the microgrid is calculated, and the power of the electrolysis hydrogen production system is changed according to the difference, thereby changing the phase and voltage in the electrolysis hydrogen production system, and then changing the duty cycle of the three-phase rectifier switch tube pulse, and finally achieving the purpose of compensating the power difference by changing the power on the DC side.

[0009] In view of the problems of insufficient moment of inertia and poor frequency stability caused by the access of a large number of new energy and clean energy to the microgrid, the present invention takes into account the regulation capability of the electrolysis hydrogen production system itself, and the APR control strategy realizes the primary frequency regulation of the grid frequency by autonomously regulating the power of the hydrogen production load. The primary frequency regulation mode of the active power active regulation control strategy is used to simulate the operating characteristics of traditional synchronous motors.

[0010] Furthermore, when a large disturbance occurs in the hydrogen production electrolysis system, resulting in a short-term frequency over-limit phenomenon, the frequency stability is restored through the secondary frequency regulation mode of the active power active regulation control strategy, and the hydrogen production load power is adjusted in real time to achieve stable control of the frequency of the hydrogen production electrolysis system.

[0011] Furthermore, the active power active regulation control strategy includes an active frequency link, a reactive voltage control link, a stator voltage equation and an inner loop current control link. The frequency modulation process of the primary frequency modulation mode is as follows:

[0012] 1) Collect the effective values ​​of voltage and current on the AC side of the electrolytic hydrogen production converter, and calculate the active power and reactive power on the AC side at this time through the active and reactive solver;

[0013] 2) When frequency deviation | |When the frequency is less than or equal to 0.2Hz, the frequency is modulated once. At this time, the specific process of the active frequency link is: first, the DC side power of the electrolytic hydrogen production converter is △ P dc-set , and the angular frequency deviation of the AC side grid The mechanical power is obtained by subtracting the result after droop control P m , and then the mechanical power P m With actual power P e The difference is then passed through the rotor motion equation to generate the reference phase and grid frequency, where the reference phase is the rotation angle of the dq coordinates of the rotor motion equation;

[0014] 3) Reactive power of the power grid through reactive voltage control link Rated reactive power The difference is calculated and compared with the reactive voltage control droop coefficient D q The product is equal to the grid rated voltage reference value U n The difference between the actual grid voltage is subtracted and the three-phase rectifier voltage E is determined through the PI regulator;

[0015] 4) Obtain the reference phase through the active frequency link and reactive voltage control link The stator voltage equation is introduced to calculate the electromotive force of the three-phase rectifier. e abc ;

[0016] Finally, based on the phase and the electromotive force of the three-phase rectifier e abc The pulse signal of the three-phase rectifier switch tube is generated through the inner loop current control link.

[0017] Furthermore, when | | When it is greater than 0.2Hz, the rotor motion equation changes in the active frequency link, and the electrolysis hydrogen production system will change the deviation of the AC side grid angular frequency. A feedback quantity is generated through PI regulation and compensated to the torque calculated by virtual damping, thereby realizing secondary frequency modulation.

[0018] In a second aspect, the present invention provides a system for actively participating in microgrid frequency regulation of an electrolytic hydrogen production converter, which comprises:

[0019] Primary frequency regulation unit: monitors the frequency change of the microgrid in real time, and adjusts the output power of the electrolytic hydrogen production converter through the primary frequency regulation mode of the active power active regulation control strategy according to the size of the frequency deviation, so that the electrolytic hydrogen production converter has inertia, damping and frequency regulation characteristics, so as to participate in the frequency regulation of the microgrid and realize the primary frequency regulation;

[0020] Among them, the primary frequency modulation mode of the active power active regulation control strategy is: when the load in the microgrid fluctuates, the difference between the active power set value and the actual active power of the microgrid is calculated, and the power of the electrolysis hydrogen production system is changed according to the difference, thereby changing the phase and voltage in the electrolysis hydrogen production system, and then changing the duty cycle of the three-phase rectifier switch tube pulse, and finally achieving the purpose of compensating the power difference by changing the power on the DC side.

[0021] Furthermore, the electrolysis hydrogen production converter actively participates in the microgrid frequency regulation system, and also includes a secondary frequency regulation unit;

[0022] The secondary frequency modulation unit: when a large disturbance occurs in the hydrogen production electrolysis system and the frequency exceeds the limit for a short time, the frequency stability is restored through the secondary frequency modulation mode of the active power active adjustment control strategy, and the hydrogen production load power is adjusted in real time to achieve stable control of the frequency of the hydrogen production electrolysis system.

[0023] In a third aspect, the present invention provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method when executing the computer program.

[0024] In a fourth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the steps of the method when executed by a processor.

[0025] The beneficial effects of the present invention are as follows: the present invention adopts an active power active regulation control strategy to realize the autonomous regulation function of the hydrogen production load and realizes primary frequency modulation, which can not only provide inertia damping support in the transient process, but also perform effective frequency regulation in the steady state. The present invention takes into account that when the system frequency has a short-term over-limit problem, the frequency stability can be restored by starting the secondary frequency modulation mode of the active power active regulation control strategy, and the hydrogen production load power can be adjusted in real time. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 A flow chart of a method for electrolysis hydrogen converter to actively participate in microgrid frequency regulation;

[0028] Figure 2 This is a topological structure diagram of the new energy electrolysis hydrogen production based on the active power active regulation control strategy (i.e., APR control strategy) of the present invention;

[0029] Figure 3 It is a framework diagram of the active power active regulation control strategy (i.e., APR control strategy) of the present invention;

[0030] Figure 4 This is a frequency simulation waveform diagram of a primary frequency modulation electrolysis hydrogen production system in an embodiment of the present invention;

[0031] Figure 5 This is a DC side power simulation waveform diagram of a primary frequency modulation electrolysis hydrogen production system in an embodiment of the present invention;

[0032] Figure 6 This is a waveform diagram of AC side power simulation of a primary frequency modulation electrolysis hydrogen production system in an embodiment of the present invention;

[0033] Figure 7 It is a power simulation waveform diagram of the secondary frequency modulation electrolysis hydrogen production system in an embodiment of the present invention;

[0034] Figure 8 A schematic diagram of a logical structure of a computer device provided in an embodiment of the present invention;

[0035] Figure 2 Middle,U abc is the grid voltage; i abc is the grid current; P AC is the active power of the power grid; Q is the reactive power of the power grid; U m is the grid voltage amplitude; ω s is the grid angular frequency; e a 、e b 、e c are the electromotive force of phase A, phase B and phase C of the three-phase rectifier respectively; U dc is the DC side voltage; I dc is the DC side current; I dc-set is the set current; △I dc is the current difference; △P dc-setis the DC side power of the hydrogen electrolysis converter; C dc is the DC side filter capacitor; L dc is the DC side filter inductor; L' is the grid side filter inductor; R' is the grid side filter resistor; U ga Indicates the grid A phase voltage, U gb Indicates the grid phase B voltage, U gc Represents the C-phase voltage of the power grid; S1 to S6 represent the switches of the six bridge arms of the three-phase rectifier; S7 and S8 represent the bridge arm switches of the DC / DC converter respectively; PWM represents the pulse signal that triggers the DC / DC converter; SVPWM represents the pulse signal that triggers the three-phase rectifier; PLL represents a phase-locked loop.

[0036] Figure 3 In, ω s is the grid angular frequency; ω0 is the synchronous generator angular frequency; △P dc-set is the power difference of hydrogen production load; P m is the mechanical power; P AC is the active power of the power grid; D is the damping coefficient; J is the inertia value; ω is the angular frequency of the rectifier; is the reference phase, which is also the rotation angle of the dq coordinate axis; Q is the reactive power of the power grid; Q set is the rated reactive power of the power grid; U N is the rated voltage of the power grid; U m is the grid voltage amplitude; E is the voltage of the three-phase rectifier; U abc is the grid voltage; e abc is the electromotive force of the three-phase rectifier; i f,abc is the three-phase rectifier current; i f,dN is the d-coordinate current of the three-phase rectifier; i f,qN is the q coordinate current of the three-phase rectifier; i f,d is the d-coordinate current; i f,q is the q coordinate current; U d is the d-coordinate voltage; U q is the q coordinate voltage; e d is the d-coordinate potential; e q is the q coordinate potential; e α is the α coordinate potential; e β is the β coordinate potential. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution 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 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 are within the scope of protection of the present invention.

[0038] Example 1

[0039] This embodiment is a method for an electrolytic hydrogen production converter to actively participate in microgrid frequency regulation. Figure 1 As shown, it monitors the frequency change of the microgrid in real time, determines the frequency deviation from the frequency change, and adjusts the output power of the electrolytic hydrogen production converter through the primary frequency modulation mode of the active power active regulation control strategy according to the size of the frequency deviation, so that the electrolytic hydrogen production converter has inertia, damping and frequency modulation characteristics, so as to participate in the frequency regulation of the microgrid and realize the primary frequency regulation. The frequency deviation is the absolute value of the difference between the frequency change and the power frequency (50Hz).

[0040] When a large disturbance occurs in the hydrogen production electrolysis system, resulting in a short-term frequency over-limit phenomenon, the frequency stability is restored through the secondary frequency regulation mode of the active power active regulation control strategy, that is, the secondary frequency regulation is realized. At the same time, the hydrogen production load power is adjusted in real time to achieve stable control of the frequency of the hydrogen production electrolysis system.

[0041] The primary frequency modulation mode of the active power active regulation control strategy is as follows: when the load in the microgrid fluctuates, the difference between the active power set value and the actual active power of the microgrid is calculated, and the power of the electrolysis hydrogen production system is changed according to the difference, thereby changing the phase and voltage in the electrolysis hydrogen production system, and then changing the duty cycle of the three-phase rectifier switch tube pulse, and finally achieving the purpose of compensating the power difference by changing the power on the DC side.

[0042] The framework of the APR control strategy of the present invention is as follows Figure 3 As shown, the APR control strategy has two frequency modulation modes, namely the primary frequency modulation mode and the secondary frequency modulation mode. The primary frequency modulation mode is used to simulate the operating characteristics of the traditional synchronous motor. |When the frequency is greater than 0.2Hz, switch S1 is closed to start the secondary frequency modulation. The difference between the primary frequency modulation and the secondary frequency modulation lies in the active frequency link. The specific process is as follows:

[0043] 1) Collect the effective values ​​of voltage and current on the AC side of the electrolytic hydrogen converter, and calculate the active power and reactive power on the AC side at this time through the active and reactive solver.

[0044] 2) When frequency deviation | |When the frequency is less than or equal to 0.2Hz, the frequency is modulated once. At this time, the specific process of the active frequency link is: first, the DC side power of the electrolytic hydrogen production converter is △ P dc-set , and the angular frequency deviation of the AC side grid The mechanical power is obtained by subtracting the result after droop control P m , and then the mechanical power P m With actual power P e The difference is then passed through the rotor motion equation to generate the reference phase and grid frequency, where the reference phase is the rotation angle of the dq coordinates of the rotor motion equation;

[0045] When | | When it is greater than 0.2Hz, the rotor motion equation changes in the active frequency link, and the electrolysis hydrogen production system will change the deviation of the AC side grid angular frequency. A feedback quantity is generated through PI regulation and compensated to the torque calculated by virtual damping, thereby realizing secondary frequency modulation.

[0046] 3) Reactive power of the power grid through reactive voltage control link Rated reactive power Difference and compare it with the droop coefficient D q The product is equal to the grid rated voltage reference value U n The difference between the actual grid voltage is subtracted and the three-phase rectifier voltage E is determined by the PI regulator.

[0047] 4) Obtain the reference phase through the active frequency link and reactive voltage control link The stator voltage equation is introduced to calculate the electromotive force of the three-phase rectifier. e abc .

[0048] Finally, based on the phase and the electromotive force of the three-phase rectifier e abc The pulse signal of the three-phase rectifier switch tube is generated through the inner loop current control link.

[0049] The APR control strategy consists of the active frequency link, the reactive voltage control link, the stator voltage equation and the inner loop current control link. The active frequency link is mainly the rotor motion equation, as shown in formula (1).

[0050] (1)

[0051] In the formula, and are the synchronous generator angular frequency and the actual grid angular frequency respectively; is the rated angular frequency; J and D are the moment of inertia and damping coefficient respectively; P e and P m are real power and mechanical power respectively; is the reference phase.

[0052] For the APR control strategy, the mechanical power and actual power at this time are related to the DC load, that is, the hydrogen production load. The specific equation is shown in formula (2).

[0053] (2)

[0054] In the formula, △P dc-set Indicates the power difference of hydrogen production load; D p is the active frequency control droop coefficient; P AC is the active power of the grid; I dc is the DC side current; I dc-set is the set current; is the DC side voltage.

[0055] The reactive voltage link in the APR control strategy is shown in equation (3).

[0056] (3)

[0057] Where U n is the rated voltage on the AC side; D q is the reactive voltage control droop coefficient; is the rated reactive power of the grid; is the reactive power of the grid.

[0058] The APR control strategy calculates the electromotive force e of the three-phase rectifier through the stator voltage equation abc , the specific equation is shown in formula (4).

[0059] (4)

[0060] In order to solve the problems of insufficient rotational inertia and poor frequency stability caused by the access of a large amount of new energy and clean energy to the microgrid, and taking into account the regulation capability of the electrolytic hydrogen production system itself, the present invention adopts the APR control strategy to realize primary frequency regulation of the grid frequency by autonomously regulating the power of the hydrogen production load; when the system frequency exceeds the limit, secondary frequency regulation can be performed, and at the same time, real-time adjustment of the hydrogen production load power can be autonomously realized.

[0061] In addition, the APR control strategy of the electrolytic hydrogen converter can also adjust the hydrogen production power according to the actual needs of the power grid to achieve more accurate frequency regulation. For example, when the power generation is high, the hydrogen production power can be increased to convert the excess electricity into hydrogen energy for storage; when the power generation is low, the hydrogen production power can be reduced to provide the necessary frequency regulation support for the power grid.

[0062] In order to verify the feasibility and effectiveness of the control strategy described in the present invention, Matlab / Simulink simulation software was used to build the following Figure 2 The simulation model of the new energy electrolysis hydrogen production system shown in FIG. 1 is composed of an IGBT three-phase rectifier, a DC / DC converter and an electrolyzer. The main circuit parameters are shown in Table 1.

[0063] Table 1 System simulation parameters

[0064]

[0065] First, a frequency modulation simulation verification is carried out. At this time, the initial state of the hydrogen production load power of the electrolysis hydrogen production system is set to 31kW, the AC side suddenly increases the load by 15kW at 3s, and the load cut-out rate is at 6s. The APR control strategy is compared with the voltage and current dual closed-loop control strategy. Figure 4 The comparison results of the frequency under the primary frequency regulation under the two control strategies are given respectively. Observing the grid frequency waveform under the APR control strategy, when the AC side load increases, the frequency drops from the initial 50Hz to 49.93Hz, and enters a stable state at 3.6s. During this process, the maximum frequency deviation is 49.88Hz. However, the dual closed-loop control strategy has poor frequency tracking accuracy. When there is a sudden load change, the frequency under the dual closed-loop control strategy fluctuates violently, and the peak value of the frequency deviation reaches 49.83Hz; it is basically stable at 3.7s, and the oscillation frequency drops from around 50Hz to around 49.87Hz. Comparing the frequency changes of the two control strategies, it can be found that the frequency change of the APR control strategy is reduced by 64.71%.

[0066] The reason for this phenomenon is that when the load on the AC side of the system increases, the increase in the active power of the power supply leads to a decrease in frequency. Figure 5 and Figure 6 As shown in the figure, the two control strategies are compared in terms of power change on the DC side and active power conversion on the AC side. When the APR control strategy is adopted, the power of the electrolyzer can be actively reduced to reduce the frequency change. In contrast, the dual closed-loop control strategy lacks a mechanism to actively adjust the power of the electrolyzer, and the power of the electrolyzer remains unchanged, resulting in greater frequency changes. When the power of the hydrogen production system decreases, although the hydrogen production rate will decrease accordingly, for the electrolysis hydrogen production system equipped with hydrogen storage equipment, it can still operate stably at a lower power in a short period of time.

[0067] Then, the secondary frequency modulation simulation verification is carried out. At this time, the system initial state hydrogen production load power is set to 30kW. At 3s, the AC side suddenly increases the load by 10kW. At 6s, another 10kW load is suddenly increased. At 9s, both loads are cut off. At this time, the frequency change waveform and power change waveform under the APR control strategy are as follows: Figure 7 As shown. By observing the waveform at this time, it can be found that at 3~6s, after the sudden increase in load, the maximum frequency deviation of the system did not exceed 49.8Hz, and there was no need to start the secondary frequency modulation. The primary frequency modulation was performed normally and finally stabilized at 49.95Hz. At 6~9s, after the sudden increase in load again, the maximum frequency deviation was 49.78Hz, and the limit was exceeded. The secondary frequency modulation was started, and the frequency finally recovered to 50Hz. When the frequency began to increase, the power on the DC side also began to adjust autonomously and began to increase. When the frequency recovered to 50Hz, the DC side frequency recovered autonomously to 31kW. At this time, the power on the AC side increased accordingly with the sudden increase in load.

[0068] In general, through the above two experiments, it can be found that when the APR control strategy performs primary frequency modulation, the frequency deviation can be reduced by autonomously adjusting the load of the electrolytic hydrogen production system, thereby achieving primary frequency modulation. When the APR control strategy performs secondary frequency modulation, the size of the electrolytic hydrogen production load can be autonomously adjusted to restore the hydrogen production load to rated operation.

[0069] Example 2

[0070] This embodiment provides a system in which an electrolysis hydrogen production converter actively participates in a microgrid frequency regulation system, which is composed of a primary frequency regulation unit and a secondary frequency regulation unit.

[0071] The primary frequency modulation unit: monitors the frequency change of the microgrid in real time, determines the frequency deviation from the frequency change, and adjusts the output power of the electrolytic hydrogen production converter through the primary frequency modulation mode of the active power active adjustment control strategy according to the size of the frequency deviation, so that the electrolytic hydrogen production converter has inertia, damping and frequency modulation characteristics, thereby participating in the frequency regulation of the microgrid;

[0072] The primary frequency modulation mode of the active power active regulation control strategy is as follows: when the load in the microgrid fluctuates, the difference between the active power set value and the actual active power of the microgrid is calculated, and the power of the electrolysis hydrogen production system is changed according to the difference, thereby changing the phase and voltage in the electrolysis hydrogen production system, and further changing the duty cycle of the three-phase rectifier switch tube pulse.

[0073] The secondary frequency modulation unit: when a large disturbance occurs in the electrolytic hydrogen production system and the frequency exceeds the limit for a short time, the frequency stability is restored through the secondary frequency modulation mode of the active power active adjustment control strategy, and the hydrogen production load power is adjusted in real time.

[0074] Specifically, the active power active regulation control strategy includes an active frequency link, a reactive voltage control link, a stator voltage equation and an inner loop current control link.

[0075] The frequency modulation process of the primary frequency modulation mode is as follows:

[0076] 1) Collect the effective values ​​of voltage and current on the AC side of the electrolytic hydrogen production converter, and calculate the active power and reactive power on the AC side at this time through the active and reactive solver;

[0077] 2) When | |When the frequency is less than or equal to 0.2Hz, the frequency is modulated once. The specific process of the active frequency link is as follows: first, the power difference of the DC side of the electrolytic hydrogen production converter △ P dc-set , and the angular frequency deviation of the AC side grid The mechanical power is obtained by subtracting the result after droop control P m , and then the mechanical power P m With actual power P e The difference is then passed through the rotor motion equation to generate the reference phase of the rotor motion equation. and grid frequency, where the reference phase is the rotation angle of the dq coordinates of the rotor motion equation;

[0078] 3) Reactive power of the power grid through reactive voltage control link Rated reactive power The difference is calculated and compared with the reactive voltage control droop coefficient D q The product is equal to the grid rated voltage reference value U n The difference between the actual grid voltage is subtracted and the three-phase rectifier voltage E is determined through the PI regulator;

[0079] 4) Obtain phase through active frequency link and reactive voltage control link The stator voltage equation is introduced with the three-phase rectifier voltage E to calculate the electromotive force of the three-phase rectifier e abc ;

[0080] Finally, based on the phase and the electromotive force of the three-phase rectifier e abc The pulse signal of the three-phase rectifier switch tube is generated through the inner loop current control link.

[0081] When | | When it is greater than 0.2Hz, the rotor motion equation changes in the active frequency link, and the electrolysis hydrogen production system will change the deviation of the AC side grid angular frequency. A feedback quantity is generated through PI regulation and compensated to the torque calculated by virtual damping, thereby realizing secondary frequency modulation.

[0082] Example 3

[0083] This embodiment provides an electronic device, comprising: at least one processor; and a memory connected to the at least one processor in communication. The memory stores a computer program executable by the at least one processor, and when the computer program is executed by the at least one processor, the electronic device executes the method according to Embodiment 1 of the present invention.

[0084] Example 4

[0085] This embodiment provides a non-transitory computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor of a computer, is used to cause the computer to execute the method according to Embodiment 1 of the present invention.

[0086] refer to Figure 8 , a block diagram of an electronic device 400 that can be used as a server or client of the present invention will now be described, which is an example of a hardware device that can be applied to various aspects of the present invention. The electronic device is intended to represent various forms of digital electronic computer devices, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0087] like Figure 8 As shown, the electronic device 400 includes a computing unit 401, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 402 or a computer program loaded from a storage unit 408 into a random access memory (RAM) 403. In the RAM 403, various programs and data required for the operation of the electronic device 400 can also be stored. The computing unit 401, the ROM 402, and the RAM 403 are connected to each other via a bus 404. An input / output (I / O) interface 405 is also connected to the bus 404.

[0088] A plurality of components in the electronic device 400 are connected to the I / O interface 405, including: an input unit 406, an output unit 407, a storage unit 408, and a communication unit 409. The input unit 406 may be any type of device capable of inputting information to the electronic device 400, and the input unit 406 may receive input digital or character information, and generate key signal inputs related to user settings and / or function control of the electronic device. The output unit 407 may be any type of device capable of presenting information, and may include, but is not limited to, a display, a speaker, a video / audio output terminal, a vibrator, and / or a printer. The storage unit 408 may include, but is not limited to, a disk, an optical disk. The communication unit 409 allows the electronic device 400 to exchange information / data with other devices via a computer network such as the Internet and / or various telecommunication networks, and may include, but is not limited to, a modem, a network card, an infrared communication device, a wireless communication transceiver, and / or a chipset, such as a Bluetooth™ device, a WiFi device, a WiMax device, a cellular communication device, and / or the like.

[0089] The computing unit 401 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the computing unit 401 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The computing unit 401 performs the various methods and processes described above. For example, in some embodiments, the aforementioned frequency adjustment method may be implemented as a computer software program, which is tangibly contained in a machine-readable medium, such as a storage unit 408. In some embodiments, part or all of the computer program may be loaded and / or installed on the electronic device 400 via the ROM 402 and / or the communication unit 409. In some embodiments, the computing unit 401 may be configured to perform the aforementioned frequency adjustment method in any other appropriate manner (e.g., by means of firmware).

[0090] The program code for implementing the method of the present invention can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer or other programmable data processing device, so that the program code, when executed by the processor or controller, enables the functions / operations specified in the flow chart and / or block diagram to be implemented. The program code can be executed entirely on the machine, partially on the machine, partially on the machine as a stand-alone software package and partially on a remote machine, or entirely on a remote machine or server.

[0091] In the context of the present invention, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or equipment. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or equipment, or any suitable combination of the foregoing. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, 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), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0092] As used herein, the terms "machine-readable medium" and "computer-readable medium" refer to any computer program product, apparatus, and / or device (e.g., disk, optical disk, memory, programmable logic device (PLD)) for providing machine instructions and / or data to a programmable processor, including a machine-readable medium that receives machine instructions as a machine-readable signal. The term "machine-readable signal" refers to any signal for providing machine instructions and / or data to a programmable processor.

[0093] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the computer. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0094] The systems and techniques described herein may be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), and the Internet.

[0095] A computer system may include clients and servers. Clients and servers are generally remote from each other and usually interact through a communication network. The relationship of client and server is generated by computer programs running on respective computers and having a client-server relationship to each other.

[0096] It is obvious that those skilled in the art can easily make various modifications to the above embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art to the present invention based on the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. A method for actively participating in microgrid frequency regulation by an electrolytic hydrogen production converter, characterized in that: Monitor the frequency change of the microgrid in real time, determine the frequency deviation from the frequency change, and adjust the output power of the electrolytic hydrogen production converter through the primary frequency modulation mode of the active power active regulation control strategy according to the size of the frequency deviation, so that the electrolytic hydrogen production converter has inertia, damping and frequency modulation characteristics, so as to participate in the frequency regulation of the microgrid; Among them, the primary frequency modulation mode of the active power active regulation control strategy: when the load in the microgrid fluctuates, the difference between the active power set value and the actual active power of the microgrid is calculated, and the power of the electrolysis hydrogen production system is changed according to the difference, thereby changing the phase and voltage in the electrolysis hydrogen production system, and then changing the duty cycle of the three-phase rectifier switch tube pulse; The active power active regulation control strategy includes active frequency link, reactive voltage control link, stator voltage equation and inner loop current control link. The frequency modulation process of the primary frequency modulation mode is as follows: 1) Collect the effective values ​​of voltage and current on the AC side of the electrolytic hydrogen production converter, and calculate the active power and reactive power on the AC side at this time through the active and reactive solver; 2) When frequency deviation | |When the frequency is less than or equal to 0.2Hz, the frequency is modulated once. At this time, the specific process of the active frequency link is: first, the DC side power of the electrolytic hydrogen production converter is P dc-set , and the angular frequency deviation of the AC side grid The mechanical power is obtained by subtracting the result after droop control P m , and then the mechanical power P m With actual power P e The difference is then passed through the rotor motion equation to generate the reference phase and grid frequency, where the reference phase is the rotation angle of the dq coordinates of the rotor motion equation; 3) Reactive power of the power grid through reactive voltage control link Rated reactive power The difference is calculated and compared with the reactive voltage control droop coefficient D q The product is equal to the grid rated voltage reference value U n The difference between the actual grid voltage is subtracted and the three-phase rectifier voltage E is determined through the PI regulator; 4) Obtain the reference phase through the active frequency link and reactive voltage control link The stator voltage equation is introduced to calculate the electromotive force of the three-phase rectifier. e abc ; Finally, based on the phase and the electromotive force of the three-phase rectifier e abc Generate a pulse signal of the three-phase rectifier switch tube through the inner loop current control link; When | | When it is greater than 0.2Hz, the rotor motion equation changes in the active frequency link, and the electrolysis hydrogen production system will change the deviation of the AC side grid angular frequency. A feedback quantity is generated through PI regulation and compensated to the torque calculated by virtual damping, thereby realizing secondary frequency modulation.

2. The method for actively participating in microgrid frequency regulation of the electrolysis hydrogen production converter according to claim 1 is characterized in that: When a large disturbance occurs in the hydrogen production system by electrolysis, resulting in a short-term frequency over-limit phenomenon, the frequency stability is restored through the secondary frequency regulation mode of the active power active regulation control strategy, and the hydrogen production load power is adjusted in real time.

3. The electrolysis hydrogen converter actively participates in the microgrid frequency regulation system, which is characterized by: include: Primary frequency regulation unit: monitors the frequency change of the microgrid in real time, determines the frequency deviation from the frequency change, and adjusts the output power of the electrolytic hydrogen production converter through the primary frequency regulation mode of the active power active regulation control strategy according to the size of the frequency deviation, so that the electrolytic hydrogen production converter has inertia, damping and frequency regulation characteristics, so as to participate in the frequency regulation of the microgrid; Among them, the primary frequency modulation mode of the active power active regulation control strategy: when the load in the microgrid fluctuates, the difference between the active power set value and the actual active power of the microgrid is calculated, and the power of the electrolysis hydrogen production system is changed according to the difference, thereby changing the phase and voltage in the electrolysis hydrogen production system, and then changing the duty cycle of the three-phase rectifier switch tube pulse; The active power active regulation control strategy includes active frequency link, reactive voltage control link, stator voltage equation and inner loop current control link. The frequency modulation process of the primary frequency modulation mode is as follows: 1) Collect the effective values ​​of voltage and current on the AC side of the electrolytic hydrogen production converter, and calculate the active power and reactive power on the AC side at this time through the active and reactive solver; 2) When frequency deviation | |When the frequency is less than or equal to 0.2Hz, the frequency is modulated once. At this time, the specific process of the active frequency link is: first, the DC side power of the electrolytic hydrogen production converter is P dc-set , and the angular frequency deviation of the AC side grid The mechanical power is obtained by subtracting the result after droop control P m , and then the mechanical power P m With actual power P e The difference is then passed through the rotor motion equation to generate the reference phase and grid frequency, where the reference phase is the rotation angle of the dq coordinate of the rotor motion equation; 3) Reactive power of the power grid through reactive voltage control link Rated reactive power The difference is calculated and compared with the reactive voltage control droop coefficient D q The product is equal to the grid rated voltage reference value U n The difference between the actual grid voltage is subtracted and the three-phase rectifier voltage E is determined through the PI regulator; 4) Obtain phase through active frequency link and reactive voltage control link The stator voltage equation is introduced to calculate the electromotive force of the three-phase rectifier. e abc ; Finally, based on the phase and the electromotive force of the three-phase rectifier e abc Generate a pulse signal of the three-phase rectifier switch tube through the inner loop current control link; When | | When it is greater than 0.2Hz, the rotor motion equation changes in the active frequency link, and the electrolysis hydrogen production system will change the deviation of the AC side grid angular frequency. A feedback quantity is generated through PI regulation and compensated to the torque calculated by virtual damping, thereby realizing secondary frequency modulation.

4. The electrolysis hydrogen production converter actively participates in the microgrid frequency regulation system according to claim 3, characterized in that: It also includes a secondary frequency modulation unit; The secondary frequency modulation unit: when a large disturbance occurs in the electrolytic hydrogen production system and the frequency exceeds the limit for a short time, the frequency stability is restored through the secondary frequency modulation mode of the active power active adjustment control strategy, and the hydrogen production load power is adjusted in real time.

5. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to claim 1 or 2 are implemented.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to claim 1 or 2 are implemented.

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