Frequency division power control method and system for energy storage system and water electrolysis hydrogen production device

Abstract

The invention discloses a frequency division power control method for an energy storage system and a water electrolysis hydrogen production device. The method comprises the following steps: according to a power relationship, a second-order low-pass filtering method, a charge state of the energy storage system and a charge state of a hydrogen production machine, obtaining a corresponding frequency-domain-based output power reference value of a storage battery and a corresponding frequency-domain-based load power reference value of the hydrogen production machine; constructing a centralized energy storage and water electrolysis hydrogen production device cooperative work frequency division power energy balance model according to the balance relationship between the working mode and the input and output power in the micro-grid, the charge state of the energy storage system and the charge state of the hydrogen production machine; and controlling a DC / DC converter in the energy storage system and a DC / DC converter in the hydrogen production machine according to the energy balance model based on the output power reference value of the storage battery and the load power reference value of the hydrogen production machine in the frequency domain so as to adjust the output power reference value of the storage battery and the load power reference value of the hydrogen production machine. The invention further provides an energy storage system and a frequency division power control system of the water electrolysis hydrogen production device.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage and conversion, and in particular to a frequency division power control method and system for an energy storage system and a water electrolysis hydrogen production device. Background Art

[0002] With the continuous growth of global energy demand and the increasing awareness of environmental protection, the development and utilization of renewable energy has become an important part of the energy strategy of countries around the world. Renewable energy such as solar energy and wind energy have become increasingly important in the energy supply system due to their clean and renewable characteristics. However, the intermittent and unstable nature of these renewable energy sources has brought great challenges to the stable operation of the power system. In order to smooth out the fluctuations of renewable energy generation and improve the flexibility and reliability of the power grid, centralized energy storage systems have emerged.

[0003] In a system where the energy storage system and the water electrolysis hydrogen production device work together, how to efficiently and reasonably distribute and control power has become a key factor affecting the overall performance and efficiency of the system. Traditional power control methods, such as simple proportional distribution and priority control, often fail to meet the system's high-precision and dynamic response requirements for power distribution. Especially when renewable energy generation fluctuates greatly and load demand changes rapidly, traditional control methods may lead to problems such as frequent charging and discharging of the energy storage system and large power fluctuations of the water electrolysis hydrogen production device, thereby reducing system energy efficiency, shortening equipment life, and even affecting the safe and stable operation of the power grid. Summary of the invention

[0004] In view of this, it is necessary to provide a frequency-divided power control method for an energy storage system and a water electrolysis hydrogen production device to solve the technical problems that traditional control methods may cause frequent charging and discharging of the energy storage system and large power fluctuations of the water electrolysis hydrogen production device.

[0005] It is also necessary to provide a frequency-divided power control system for an energy storage system and a water electrolysis hydrogen production device.

[0006] A frequency division power control method for an energy storage system and a water electrolysis hydrogen production device, comprising the following steps:

[0007] According to the power relationship in the system in which the energy storage system and the hydrogen generator work together, the second-order low-pass filtering method, the charge state of the energy storage system, and the charge state of the hydrogen generator, the corresponding frequency-domain-based battery output power reference value and the hydrogen generator load power reference value are obtained;

[0008] According to the working mode of the cooperative working system of the energy storage system and the water electrolysis hydrogen production device in the microgrid, the balance relationship between the input and output power in the microgrid, the charge state of the energy storage system, and the charge state of the hydrogen generator, a frequency-divided power energy balance model of the coordinated working of the centralized energy storage and the water electrolysis hydrogen production device is constructed;

[0009] According to the frequency-division power energy balance model of the coordinated working of centralized energy storage and water electrolysis hydrogen production device and the output power reference value of the battery and the load power reference value of the hydrogen generator based on the frequency domain, the DC / DC converter in the energy storage system and the DC / DC converter in the hydrogen generator are controlled to adjust the output power reference value of the battery and the load power reference value of the hydrogen generator.

[0010] A frequency-divided power control system for an energy storage system and a water electrolysis hydrogen production device, comprising: a power reference value acquisition module, a cooperative frequency-divided power energy balance module and a DC / DC converter control module,

[0011] The power reference value acquisition module is used to obtain the corresponding frequency-domain-based battery output power reference value and hydrogen generator load power reference value according to the power relationship in the system in which the energy storage system and the hydrogen generator work together, the second-order low-pass filtering method, the charge state of the energy storage system, and the charge state of the hydrogen generator;

[0012] The collaborative working frequency division power energy balance module is used to construct a frequency division power energy balance model of the collaborative working of the centralized energy storage and the water electrolysis hydrogen production device according to the working mode of the collaborative working system of the energy storage system and the water electrolysis hydrogen production device in the microgrid, the balance relationship between the input and output power in the microgrid, the charge state of the energy storage system, and the charge state of the hydrogen production machine;

[0013] The DC / DC converter control module is used to control the DC / DC converter in the energy storage system and the DC / DC converter in the hydrogen generator according to the frequency-division power energy balance model of the coordinated working of the centralized energy storage and the water electrolysis hydrogen production device, the output power reference value of the battery, and the load power reference value of the hydrogen generator, so as to adjust the output power reference value of the battery and the load power reference value of the hydrogen generator.

[0014] In the above energy storage system and the frequency division power control method and system of the water electrolysis hydrogen production device, by introducing the adjustment frequency division control method based on the SOC of the energy storage element, it is possible to achieve more accurate and stable control of the hybrid energy storage system, effectively suppress power fluctuations, and improve the stability and reliability of the system. On this basis, by dynamically adjusting the power distribution of the energy storage element, it is ensured that it works within a safe range to avoid overcharging or over-discharging, thereby extending the service life of the energy storage element. At the same time, the method and system can be adjusted and optimized accordingly according to the needs of different working modes to improve the overall performance of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a frequency division power control block diagram of the energy storage system and water electrolysis hydrogen production device proposed in the present invention.

[0016] Figure 2This is a control principle diagram of the frequency division power energy balance model of the energy storage system and the water electrolysis hydrogen production device working in coordination with the frequency division control method proposed in the present invention.

[0017] Figure 3 It is the response characteristics of the DC bus voltage and current, the hydrogen generator voltage and current, and the energy storage system when the AC bus voltage and current change.

[0018] Figure 4 It is the response characteristics of the energy storage system power and the electrolyzer EDL equivalent capacitor power when the generator side power fluctuates.

[0019] Figure 5 This is a functional module diagram of the frequency-divided power control system of the energy storage system and the water electrolysis hydrogen production device proposed in the present invention.

[0020] In the figure: a power reference value acquisition module 20, a cooperative frequency division power energy balance module 30, and a DC / DC converter control module 40. DETAILED DESCRIPTION

[0021] This application adopts a frequency division power control strategy, which separates the total power demand in the frequency domain to obtain power components in different frequency bands, and performs targeted control according to the characteristics of each component to solve the problems existing in traditional control methods. Specifically: frequency division power control can decompose the total power demand into low-frequency power components and high-frequency power components according to the characteristics of the energy storage system and the hydrogen generator. The low-frequency power component usually corresponds to power fluctuations on a longer time scale, and is suitable for charging and discharging regulation by a centralized energy storage system to smooth the grid load and improve the power supply quality; the high-frequency power component corresponds to power changes on a short time scale, and is suitable for rapid response by the hydrogen generator to meet the real-time hydrogen production power demand and improve system flexibility.

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] A frequency division power control method based on energy storage system and water electrolysis hydrogen production device, please also refer to Figure 1 , Figure 1It is a frequency-divided power control block diagram of the energy storage system and the water electrolysis hydrogen production device proposed in the present invention, wherein the control module is divided into a power generation side control and a load side control. The power generation side control leads out the DC bus voltage and power in the AC / DC rectifier module; the load side control introduces a power reference value in the DC / DC converter of the electrolyzer and the energy storage system, and controls it through the PI link and the PWM link.

[0024] The frequency division power control method based on the energy storage system and the water electrolysis hydrogen production device comprises the following steps:

[0025] Step S100, obtaining a corresponding frequency-domain-based battery output power reference value and a hydrogen generator load power reference value according to a power relationship in a system in which an energy storage system and a hydrogen generator work in coordination, a second-order low-pass filtering method, and a charge state of the energy storage system and a charge state of the hydrogen generator;

[0026] Step S200, constructing a frequency-divided power energy balance model of the coordinated working of the centralized energy storage and the water electrolysis hydrogen production device according to the working mode of the coordinated working system of the energy storage system and the water electrolysis hydrogen production device in the microgrid, the balance relationship between the input and output power in the microgrid, the charge state of the energy storage system, and the charge state of the hydrogen generator;

[0027] Step S300, according to the frequency-divided power energy balance model of the coordinated working of the centralized energy storage and the water electrolysis hydrogen production device, the output power reference value of the battery, and the load power reference value of the hydrogen production machine, the DC / DC converter in the energy storage system and the DC / DC converter in the hydrogen production machine are controlled to adjust the output power reference value of the battery and the load power reference value of the hydrogen production machine.

[0028] Wherein, step S100 is specifically as follows:

[0029] (1) In a system where the energy storage system and the hydrogen generator work together, the power relationship can be expressed as:

[0030] P V +P bat =P line +P HE (1)

[0031] Where: P V is the output power of the power generation side; P bat is the output power of the battery; it is positive when the energy element is discharging and negative when it is charging; P line is the grid-connected power, which is positive when discharging to the grid and negative when absorbing grid energy; P HE is the load power of the hydrogen generator;

[0032] (2) Using the second-order low-pass filtering method, two low-pass filters with different cutoff frequencies are used to filter P V Divided into 3 frequency bands, the time constant THE <T bat , using a filter with a higher cut-off frequency, the reference value P of the output power of the double-layer capacitor (EDL) of the electrolytic water hydrogen production device is obtained HE_ref The output power of the electric double layer capacitor (EDL) is the reference value of the load power of the hydrogen generator. The intermediate frequency part is removed by using a filter with a lower cut-off frequency and is used as the reference value of the output power of the battery P bat_ref , the principle is as follows:

[0033]

[0034] The time constant T HE and T bat Need to be determined by actual working status;

[0035] (3) When the SOC of the energy storage element is close to the threshold, it is necessary to be able to correct the output power reference value to ensure that the SOC is always within a safe range. Therefore, the SOC limit of the energy storage element is added on the basis of the second-order frequency division control. The energy storage element includes the double-layer capacitor of the water electrolysis hydrogen production device and the battery of the energy storage system. The SOC includes the SOC bat and SOC HE ;

[0036] The remaining capacity SOC of the energy storage element bat and SOC HE Real-time acquisition is performed, and then compared with the corresponding X, X is the basic threshold (for example, X is 60%), and it is amplified proportionally and fed back to the second-order low-pass filter method. The power reference values ​​of different energy storage elements are:

[0037]

[0038] Where: K 1 and K 2 is the proportional magnification factor. Further analysis of the above relationship shows that SOC HE When SOC < X, the reference value of the equivalent capacitance output power of the electrolytic cell EDL will decrease. In this case, the continuous decrease of the remaining power can be slowed down; assuming that SOC HE >X, the reference value of the equivalent capacitance output power of the electrolytic cell EDL increases, so the situation of the continuous increase of the remaining power can be slowed down; SOC bat When SOC < X, the reference value of the energy storage battery output power will decrease. In this case, the situation of the continuous decrease of the remaining power can be slowed down; assuming that SOC bat>X, the reference value of the energy storage battery output power increases, so the situation of the continuous increase of the remaining power can be slowed down.

[0039] Wherein, step S200 is specifically as follows:

[0040] (1) Under different operating conditions, the working modes of the energy storage system in the microgrid and the water electrolysis hydrogen production device are different. The control strategy of the energy storage element needs to be changed at any time, taking into account the balance relationship between input and output power and the SOC of the battery. bat , SOC of the equivalent capacitance of the electrolytic cell EDL HE , the following four working modes of energy balance model strategy are constructed, please also refer to Figure 2 :

[0041] Where P V is the output power of the power generation side; P HE is the load power of the hydrogen generator; SOC HE SOC is the state of charge of the electrolytic cell EDL capacitor; bat SOC is the state of charge of the battery. bat_max is the upper limit of battery SOC; SOC bat_min is the lower limit of battery SOC; SOC HE_max is the upper limit of SOC of the electrolytic cell EDL capacitor; SOC HE_min The lower limit of SOC of the electrolytic cell EDL capacitor;

[0042] (2) Working mode 1 is the normal working mode. At this time, the energy storage element can well smooth the power fluctuation, the microgrid system works normally, and the output power is balanced with the load demand power. V Greater than the load power P HE When the excess power is in the process of being used, it will be absorbed by the double-layer capacitor of the water electrolysis hydrogen production device and the battery of the energy storage system. Otherwise, it will be compensated by the energy storage element.

[0043] (3) Working mode 2: When SOC HE If the SOC exceeds the set value, bat Normal, because the electrolytic cell EDL capacitor processes the high-frequency part of the power fluctuation, the electrolytic cell EDL capacitor will stop working at this time, which will reduce the energy storage system's ability to suppress high-frequency power fluctuations. Therefore, it is necessary to make SOC HE After returning to a safe range, the mode can be divided into the following four working states according to the balance relationship of output power:

[0044] SOC HE <SOC HE_min , P V >P HE , no adjustment is made at this time;

[0045] SOC HE <SOC HE_min , P V <P HE At this time, it is necessary to increase the output of the battery of the energy storage system so that the EDL capacitor of the electrolyzer absorbs the excess power to increase the SOC HE , back to normal;

[0046] SOC HE >SOC HE_max , P V <P HE , no adjustment is made at this time;

[0047] SOC HE >SOC HE_max , P V >P HE , using the battery charging in the energy storage system to absorb the remaining power and discharge the electrolyzer EDL capacitor to a certain extent;

[0048] (4) Working mode 3: When SOC bat If the SOC exceeds the set normal value, HE Under normal circumstances, since the energy storage system processes the low-frequency part of the power fluctuation, if the energy storage system stops working, the ability to suppress power fluctuation will be weakened for a long time. In addition, because the battery capacity of the energy storage system is much larger than the electrolytic cell EDL capacitor, it is difficult to control the output of the electrolytic cell EDL capacitor to meet the overall needs of the system. At this time, it can also be divided into three working states:

[0049] SOC bat <SOC bat_min , P V >P HE , no adjustment is made at this time;

[0050] SOC bat <SOC bat_min , P V <P HE , at this time, the electrolytic cell power needs to be adjusted, for example, the electrolytic cell power is adjusted according to the process in step S300;

[0051] SOC bat >SOC bat_max , P V <P HE , no adjustment is made at this time;

[0052] SOC bat >SOC bat max , P V >P HE, at this time, the output power of the power generation side is adjusted, for example, by controlling the AC / DC rectifier module to ensure the stability of the DC bus voltage and power derived from the AC / DC rectifier module;

[0053] (5) Working mode 4: When the SOC of the energy storage elements exceeds the set value, the working state can be divided into the following 8 types:

[0054] SOC bat >SOC bat_max , SOC HE >SOC HE_max , P V <P HE , no adjustment is made at this time;

[0055] SOC bat >SOC bat_max , SOC HE >SOC HE_max , P V >P HE At this time, the control strategy and the "SOC bat >SOC bat_max , P V >P HE , at this time adjust the output power of the power generation side; "same;

[0056] SOC bat <SOC bat_min , SOC HE <SOC HE_min , P V >P HE , no adjustment is made at this time;

[0057] SOC bat <SOC bat_min , SOC HE <SOC HE_min , P V <P HE At this time, the control strategy and the "SOC bat <SOC bat_min , P V <P HE , at this time, the electrolytic cell power needs to be adjusted; "same;

[0058] SOC bat >SOC bat_max , SOC HE <SOC HE_min , P V <P HE At this time, the control strategy and the "SOC HE <SOC HE_min , PV <P HE At this time, it is necessary to increase the output of the battery of the energy storage system so that the EDL capacitor of the electrolyzer absorbs the excess power to increase the SOC HE , back to normal;”Same;

[0059] SOC bat >SOC bat_max , SOC HE <SOC HE_min , P V >P HE At this time, the control strategy and the "SOC bat >SOC bat_max , P V >P HE , at this time adjust the output power of the power generation side; "same;

[0060] SOC bat <SOC bat_min , SOC HE >SOC HE_max , P V >P HE At this time, the control strategy and the "SOC HE >SOC HE_max , P V >P HE , using the battery charging in the energy storage system to absorb the remaining power and discharge the electrolyzer EDL capacitor to a certain extent” is the same;

[0061] SOC bat <SOC bat_min , SOC HE >SOC HE_max , P V <P HE At this time, the control strategy and the "SOC bat <SOC bat_min , P V <P HE , at this time, the electrolytic cell power needs to be adjusted; "same.

[0062] Wherein, step S300 is specifically as follows:

[0063] Regarding the control of the DC / DC converter of the energy storage system, when the circuit works in the Boost state, T 1 Tube off, T 2 The tube works by modulating T 2The duty cycle D of the tube is used to realize the discharge of the energy storage element. E is the equivalent voltage source on the energy storage side; I is the current flowing through the inductor; R is the resistance on the load side; C is the capacitance on the load side; L is the inductor on the energy storage side; the energy flow direction is selected as the reference direction of the current; let T 2 The duty cycle of the tube is D, D = T on / T, where T on T 2 The conduction time of the tube, assuming U 0 is the terminal voltage on the energy storage side, U dc is the output DC side voltage;

[0064] When T 2 Tube at T on When the time period is , the current I is used as the state variable, and the state equation can be expressed as:

[0065]

[0066] When T 2 Tube at T off When the time period is , the following state equation is obtained:

[0067]

[0068] The following state equation is obtained by using the average state method:

[0069]

[0070] By transforming formula (6), we can get the following formula:

[0071]

[0072] The small signal transfer function in Boost mode is obtained by frequency domain transformation of equations (7) and (8):

[0073]

[0074] Among them, in Boost mode, is the transfer function of the DC bus voltage to the duty cycle, It is the transfer function of DC bus voltage to inductor current. Both can reflect the influence of duty cycle and inductor current change on DC bus voltage. I-D(s) Based on the transfer function Transfer Function Generate a corresponding current signal and provide the current signal to the modulation loop and the DC / DC converter of the energy storage system; G I-D(s) for The transfer function of the controller represents the transfer function of the inductor current to the duty cycle;

[0075] When the circuit works in Buck mode, T 1 Tube work, T 2 To turn off, just control T 1 The duty cycle D' of the tube can be obtained by deriving the following formula:

[0076]

[0077]

[0078] In Buck state T 1 The duty cycle is D', and its small signal transfer function expression is:

[0079]

[0080] G M (s)=1(17)

[0081] Among them, in Buck mode, is the transfer function of output voltage to duty cycle, reflecting the effect of duty cycle change on output voltage; G I_D' (s) is the transfer function of the inductor current to the duty cycle. Figure 1 Specifically manifested in The transfer function of the controller; G PI (s) is the transfer function of the PI controller; G M (s) is the transfer function of the modulation loop;

[0082] According to the above-mentioned centralized energy storage and water electrolysis hydrogen production device cooperative working frequency division power energy balance model, the output power reference value P is obtained. bat_ref Since the output DC voltage is constant, the power reference value of the battery and the actual battery voltage U bat Multiply the inverse of the value and obtain the output current reference value i accordingly. bat_ref Then compare it with the actual current i bat Subtract the current deviation value and introduce the current deviation value into the transfer function G of PI control PI (s) Generates an adjusted control signal value, which is introduced into the transfer function G controlled by the PWM module M (s) generates a pulse signal, and the generated pulse signal introduces the transfer function An actual current value is generated, and a DC / DC converter of the energy storage system is controlled by the actual current value to adjust the output power reference value of the battery, and the actual current value is provided to the modulation loop as the negative feedback signal.

[0083] The DC / DC converter control of the equivalent capacitance of the electrolyzer EDL is as follows: According to the above-mentioned centralized energy storage and water electrolysis hydrogen production device cooperative working frequency division power energy balance model, the output power reference value P is obtained. HE_ref , the power reference value P of the equivalent capacitance of the electrolytic cell EDL HE_ref and the actual voltage U of the equivalent capacitance of the electrolytic cell EDL HE Multiply the inverse of the value and obtain the output current reference value i accordingly. HE_ref Then compare it with the actual current i HE Subtract the current deviation value and introduce the current deviation value into the transfer function G of PI control PI (s) Generates an adjusted control signal value, which is introduced into the transfer function G controlled by the PWM module M (s) generates a pulse signal, and the generated pulse signal introduces the transfer function Generate an actual current value, use the actual current value to control the DC / DC converter of the electrolyzer to adjust the load power reference value of the electrolyzer, and provide the actual current value as the negative feedback signal to the modulation loop. bat <SOC bat_min , P v <P HE When the output power reference value P is obtained by "according to the above-mentioned centralized energy storage and water electrolysis hydrogen production device coordinated work frequency division power energy balance model HE_ref , the power reference value P of the equivalent capacitance of the electrolytic cell EDL HE_ref and the actual voltage U of the equivalent capacitance of the electrolytic cell EDL HE Multiply the inverse of the value and obtain the output current reference value i accordingly. HE_ref Then compare it with the actual current i HE Subtract the current deviation value and introduce the current deviation value into the transfer function G of PI control PI (s) Generates an adjusted control signal value, which is introduced into the transfer function G controlled by the PWM module M (s) generates a pulse signal, and the generated pulse signal introduces the transfer function Generate an actual current value, use the actual current value to control the DC / DC converter of the electrolytic cell to adjust the load power reference value of the electrolytic cell, and provide the actual current value as the negative feedback signal to the modulation loop to adjust the load power of the electrolytic cell.

[0084] Please see Figure 3 , Figure 4 , Figure 4 , Figure 3 In accordance with Figure 1The simulation results of the response characteristics of the DC bus voltage and the power output of the controller when the input power of the machine-side converter and the AC bus voltage and current amplitude of the energy storage system and the water electrolysis hydrogen production device system of the structural structure change, and the specific parameters are shown in Table 1:

[0085] Table 1 Centralized energy storage and hydrogen generator system and controller parameters

[0086] parameter symbol dimension Numeric DC bus voltage <![CDATA[Ud c ]]> V 1000 Energy storage unit equivalent voltage source E V 600 Energy storage unit equivalent internal resistance <![CDATA[R 1 ]]> Ω 0.021 Inductance L mh 10 Capacitance C μF 1000 Equivalent load R Ω 40 PWM carrier frequency <![CDATA[f p ]]> kHz 10 Low pass filter cutoff frequency <![CDATA[f 1 ]]> kHz 10 Proportional coefficient <![CDATA[k p ]]> 1 5 Integration coefficient <![CDATA[K i ]]> 1 20

[0087] Figure 4 In the figure, when the power on the generator side fluctuates, the corresponding response characteristics of the energy storage system power and the electrolyzer EDL equivalent capacitor power are shown. At the beginning, the energy storage system and the electrolyzer EDL equivalent capacitor respond to different frequency powers. The power on the generator side fluctuates at 3s, and the energy storage system power and the electrolyzer EDL equivalent capacitor change accordingly. The capacitor first recovers to a stable value, and then the energy storage system recovers to a stable value. It can be seen that the frequency division control method used can make the system output power be absorbed by different energy storage elements at different frequencies, and the system can be in a stable state under fluctuations; in Figure 3 In the figure, the DC bus voltage and current, the hydrogen generator voltage and current, and the energy storage system response characteristics are shown when the AC bus voltage and current change. The DC bus current amplitude changes at 3.5s, and the DC bus voltage is not affected. The corresponding hydrogen generator voltage and current and energy storage system voltage and current will change accordingly, but will soon stabilize. It can be seen that the DC bus voltage and the voltage and current output by the controller show good anti-interference ability under the above step disturbances.

[0088] Further, please also see Figure 5 The present application also provides a frequency-divided power control system for an energy storage system and a water electrolysis hydrogen production device, including: a power reference value acquisition module 20, a collaborative working frequency-divided power energy balance module 30 and a DC / DC converter control module 40.

[0089] The power reference value acquisition module 20 is used to obtain the corresponding frequency-domain-based battery output power reference value and hydrogen generator load power reference value based on the power relationship in the system in which the energy storage system and the hydrogen generator work together, the second-order low-pass filtering method, the charge state of the energy storage system, and the charge state of the hydrogen generator; the power reference value acquisition module 20 obtains the frequency-domain-based battery output power reference value and hydrogen generator load power reference value from the AC / DC rectifier module on the power supply side. Specifically, the power reference value acquisition module 20 is configured to execute the specific implementation steps of the above step S100 to achieve the acquisition of the frequency-domain-based battery output power reference value and hydrogen generator load power reference value.

[0090] The collaborative working frequency division power energy balance module 30 is used to construct a centralized energy storage and water electrolysis hydrogen production device collaborative working frequency division power energy balance model according to the working mode of the energy storage system and the water electrolysis hydrogen production device collaborative working system in the microgrid, the balance relationship between the input and output power in the microgrid, the charge state of the energy storage system, and the charge state of the hydrogen generator; specifically, the collaborative working frequency division power energy balance module 30 implements the construction of the centralized energy storage and water electrolysis hydrogen production device collaborative working frequency division power energy balance model and the control of the DC / DC converter control module by executing the specific implementation steps of the above-mentioned step S200, for example, the collaborative working frequency division power energy balance module determines the SOC HE <SOC HE_min , P V <P L , output a first control signal to the DC / DC converter control module, so as to utilize the DC / DC converter control module to increase the output of the battery of the energy storage system, so that the electrolytic cell EDL capacitor absorbs excess power to increase the SOC HE , back to normal.

[0091] The DC / DC converter control module 40 is used to control the DC / DC converter in the energy storage system and the DC / DC converter in the hydrogen generator according to the frequency-divided power energy balance model of the coordinated operation of the centralized energy storage and the water electrolysis hydrogen production device, the output power reference value of the battery, and the load power reference value of the hydrogen generator, so as to adjust the output power reference value of the battery and the load power reference value of the hydrogen generator; the DC / DC converter control module 40 includes an energy storage DC / DC control unit and an electrolyzer DC / DC control unit. Specifically, the DC / DC converter control module 40 implements the adjustment of the output power reference value of the battery and the load power reference value of the hydrogen generator by executing the specific implementation steps of the above step S300. For example, after the DC / DC converter control module receives the first control signal, Figure 1 The energy storage DC / DC control unit in the bat_ref , and the actual battery voltage U bat Multiply the inverse of the value and obtain the output current reference value i accordingly. bat ref Then compare it with the actual current i bat Subtract the current deviation value and introduce the current deviation value into the transfer function G of the PI control in the energy storage DC / DC control unit. PI (s ) Generate an adjusted control signal value, which is introduced into the transfer function G controlled by the PWM module in the energy storage DC / DC control unit M (s) generates a pulse signal, and the generated pulse signal introduces the transfer function An actual current value is generated, and the generated actual current value is used to control the DC / DC converter of the energy storage system to adjust the output power reference value of the battery, and the actual current value is provided to the modulation loop as the negative feedback signal.

[0092] Although the above describes an illustrative specific embodiment of the present invention so that those skilled in the art can understand the present invention, it should be clear that the present invention is not limited to the scope of the specific embodiment. As long as various changes are within the scope of the spirit and limitations of the claims attached to the present invention, these changes are obvious, and all inventions and creations using the concepts of the present invention are protected.

Claims

1. A frequency division power control method for an energy storage system and a water electrolysis hydrogen production device, characterized in that: The following steps are involved: Step S100, obtaining a corresponding frequency-domain-based battery output power reference value and a hydrogen generator load power reference value according to a power relationship in a system in which an energy storage system and a hydrogen generator work in coordination, a second-order low-pass filtering method, and a charge state of the energy storage system and a charge state of the hydrogen generator; Step S200, constructing a frequency-divided power energy balance model of the coordinated working of the centralized energy storage and the water electrolysis hydrogen production device according to the working mode of the coordinated working system of the energy storage system and the water electrolysis hydrogen production device in the microgrid, the balance relationship between the input and output power in the microgrid, the charge state of the energy storage system, and the charge state of the hydrogen generator; Step S300, according to the frequency-divided power energy balance model of the coordinated working of the centralized energy storage and the water electrolysis hydrogen production device, the output power reference value of the battery, and the load power reference value of the hydrogen production machine, the DC / DC converter in the energy storage system and the DC / DC converter in the hydrogen production machine are controlled to adjust the output power reference value of the battery and the load power reference value of the hydrogen production machine.

2. The frequency division power control method of the energy storage system and the water electrolysis hydrogen production device according to claim 1 is characterized in that: Step S100 is specifically as follows: (1) In a system where the energy storage system and the hydrogen generator work together, the power relationship can be expressed as: P V +P bat =P line +P HE (1) Where: P V is the output power of the power generation side; P bat is the output power of the battery; it is positive when the energy element is discharging and negative when it is charging; P line is the grid-connected power, which is positive when discharging to the grid and negative when absorbing grid energy; P HE is the load power of the hydrogen generator; (2) Using the second-order low-pass filtering method, two low-pass filters with different cutoff frequencies are used to filter P V Divided into 3 frequency bands, Time constant T HE <T bat , using a filter with a higher cut-off frequency, the reference value P of the output power of the double-layer capacitor (EDL) of the electrolytic water hydrogen production device is obtained HE_ref The output power of the double-layer capacitor is the reference value of the load power of the hydrogen generator. The intermediate frequency part is removed by using a filter with a lower cut-off frequency and is used as the output power reference value P of the battery. bat_ref , the principle is as follows: The time constant T HE and T bat Need to be determined by actual working status; (3) Based on the second-order frequency division control, the SOC limit of the energy storage element is added, where the energy storage element includes the double-layer capacitor of the water electrolysis hydrogen production device and the battery of the energy storage system. The SOC includes SOC bat and SOC HE ; The remaining capacity SOC of the energy storage element bat and SOC HE Real-time acquisition is performed, and then compared with the corresponding X, X is the basic threshold, amplified by proportion, and fed back to the second-order low-pass filter method. The power reference values ​​of different energy storage elements are: Where: K1 and K2 are proportional magnification coefficients. Further analysis of the above relationship shows that SOC HE When SOC < X, the reference value of the equivalent capacitance output power of the electrolytic cell EDL will decrease. In this case, the continuous decrease of the remaining power can be slowed down; assuming that SOC HE >X, the reference value of the equivalent capacitance output power of the electrolytic cell EDL increases, so the situation of the continuous increase of the remaining power can be slowed down; SOC bat When SOC < X, the reference value of the energy storage battery output power will decrease. In this case, the situation of the continuous decrease of the remaining power can be slowed down; assuming that SOC bat >X, the reference value of the energy storage battery output power increases, so the situation of the continuous increase of the remaining power can be slowed down.

3. The frequency division power control method of the energy storage system and the water electrolysis hydrogen production device according to claim 1 is characterized in that: Step S200 is specifically as follows: Construct the energy balance model strategy of the following four working modes, where P V is the output power of the power generation side; P HE is the load power of the electrolyzer; SOC HE SOC is the state of charge of the electrolytic cell EDL capacitor; bat SOC is the state of charge of the battery. bat_max The upper limit of battery SOC; SOC bat_min is the lower limit of battery SOC; SOC HE_max The upper limit of SOC of the electrolytic cell EDL capacitor; SOC HE_min The lower limit of SOC of the electrolytic cell EDL capacitor; Working mode 1 is the normal working mode. At this time, the energy storage element can well suppress power fluctuations, the microgrid system works normally, and the output power and load power are balanced. V Greater than the load power P HE When the excess power is , the double-layer capacitor of the water electrolysis hydrogen production device and the battery of the energy storage system will absorb it. Otherwise, it will be compensated by the energy storage element. Working mode 2: When SOC HE If the SOC exceeds the set value, bat Normal, because the electrolytic cell EDL capacitor processes the high-frequency part of the power fluctuation, the electrolytic cell EDL capacitor will stop working at this time, which will reduce the energy storage system's ability to suppress high-frequency power fluctuations. Therefore, it is necessary to make SOC HE After returning to a safe range, the mode can be divided into the following four working states according to the balance relationship of output power: SOC HE <SOC HE_min , P V >P HE , no adjustment is made at this time; SOC HE <SOC HE_min , P V <P HE At this time, it is necessary to increase the output of the battery of the energy storage system so that the EDL capacitor of the electrolyzer absorbs the excess power to increase the SOC HE , back to normal; SOC HE >SOC HE_max , P V <P HE , no adjustment is made at this time; SOC HE >SOC HE_max , P V >P HE , using the battery charging in the energy storage system to absorb the remaining power and discharge the electrolyzer EDL capacitor to a certain extent; Working mode 3: When SOC bat If the SOC exceeds the set normal value, HE Under normal circumstances, since the energy storage system processes the low-frequency part of the power fluctuation, if the energy storage system stops working, the ability to suppress power fluctuation will be weakened for a long time. In addition, because the battery capacity of the energy storage system is much larger than the electrolytic cell EDL capacitor, it is difficult to control the output of the electrolytic cell EDL capacitor to meet the overall needs of the system. At this time, it can also be divided into three working states: SOC bat <SOC bat_min , P V >P HE , no adjustment is made at this time; SOC bat <SOC bat_min , P V <P HE , at this time, the electrolytic cell power needs to be adjusted, for example, the electrolytic cell power is adjusted according to the process in step S300; SOC bat >SOC bat_max , P V <P HE , no adjustment is made at this time; SOC bat >SOC bat_max , P V >P HE , at this time, adjust the output power of the power generation side; Working mode 4: When the SOC of the energy storage elements exceeds the set value, the working state can be divided into the following 8 types: SOC bat >SOC bat_max , SOC HE >SOC HE_max , P V <P HE , no adjustment is made at this time; SOC bat >SOC bat_max , SOC HE >SOC HE_max , P V >P HE At this time, the control strategy and the "SOC bat >SOC bat_max , P V >P HE , at this time adjust the output power of the power generation side; "same; SOC bat <SOC bat_min , SOC HE <SOC HE_min , P V >P HE , no adjustment is made at this time; SOC bat <SOC bat_min , SOC HE <SOC HE_min , P V <P HE At this time, the control strategy and the "SOC bat <SOC bat_min , P V <P HE , at this time, the electrolytic cell power needs to be adjusted; "same; SOC bat >SOC bat_max , SOC HE <SOC HE_min , P V <P HE At this time, the control strategy and the "SOC HE <SOC HE_min , P V <P HE At this time, it is necessary to increase the output of the battery of the energy storage system so that the EDL capacitor of the electrolyzer absorbs the excess power to increase the SOC HE , back to normal;”Same; SOC bat >SOC bat_max , SOC HE <SOC HE_min , P V >P HE At this time, the control strategy and the "SOC bat >SOC bat_max , P V >P HE , at this time, adjust the output power of the power generation side to be the same; SOC bat <SOC bat_min , SOC HE >SOC HE_max , P V >P HE At this time, the control strategy and the "SOC HE >SOC HE_max , P V >P HE , using the battery charging in the energy storage system to absorb the remaining power and discharge the electrolyzer EDL capacitor to a certain extent” is the same; SOC bat <SOC bat_min , SOC HE >SOC HE_max , P V <P HE At this time, the control strategy and the "SOC bat <SOC bat_min , P V <P HE , at this time, the electrolytic cell power needs to be adjusted; "same.

4. The frequency division power control method of the energy storage system and the water electrolysis hydrogen production device according to claim 1 is characterized in that: Step S300 is specifically as follows: When the circuit works in the Boost state, T1 is turned off and T2 is working. The discharge of the energy storage element is achieved by modulating the duty cycle D of T2. E is the equivalent voltage source on the energy storage side; I is the current flowing through the inductor; R is the resistance on the load side; C is the capacitance on the load side; L is the inductor on the energy storage side; the energy flow direction is selected as the reference direction of the current; let the duty cycle of T2 be D, D=T on / T, where T on is the conduction time of tube T2, U0 is the terminal voltage on the energy storage side, U dc is the output DC side voltage; When the T2 tube is in T on When the time period is , the current I is used as the state variable, and the state equation can be expressed as: When the T2 tube is in T off When the time period is , the following state equation is obtained: The following state equation is obtained by using the average state method: By transforming formula (6), we can get the following formula: The small signal transfer function in Boost mode is obtained by frequency domain transformation of equations (7) and (8): Among them, in Boost mode, is the transfer function of the DC bus voltage to the duty cycle, It is the transfer function of DC bus voltage to inductor current. Both can reflect the influence of duty cycle and inductor current change on DC bus voltage. Based on the transfer function Transfer Function Generates the corresponding current signal, And provide the current signal to the modulation loop and the DC / DC converter of the energy storage system; G I-D(s) for The transfer function of the controller; When the circuit works in the Buck state, T1 is working and T2 is off. We only need to control the duty cycle D' of T1. The following formula can be derived: In the Buck state, the duty cycle of T1 is D', and its small signal transfer function expression is: G M (s)=1 (17) Among them, in Buck mode, is the transfer function of output voltage to duty cycle, reflecting the effect of duty cycle change on output voltage; G I_D' (s) is the transfer function of the inductor current to the duty cycle, G PI (s) is the transfer function of the PI controller; G M (s) is the transfer function of the modulation loop; The above transfer function is used to control the DC / DC converter in the energy storage system and the DC / DC converter in the hydrogen generator to adjust the output power reference value of the battery and the load power reference value of the hydrogen generator.

5. The frequency division power control method of the energy storage system and the water electrolysis hydrogen production device according to claim 4, characterized in that: "Using the above transfer function to control the DC / DC converter in the energy storage system to adjust the output power reference value of the battery" is specifically: According to the above-mentioned centralized energy storage and water electrolysis hydrogen production device cooperative working frequency division power energy balance model, the output power reference value P is obtained. bat_ref Since the output DC voltage is constant, on this basis, the power reference value of the battery and the actual battery voltage U bat Multiply the inverse of the value and obtain the output current reference value i accordingly. bat_ref Then compare it with the actual current i bat Subtract the current deviation value and introduce the current deviation value into the transfer function G of PI control PI (s) Generates an adjusted control signal value, which is introduced into the transfer function G controlled by the PWM module M (s) generates a pulse signal, and the generated pulse signal introduces the transfer function An actual current value is generated, and a DC / DC converter of the energy storage system is controlled by the actual current value to adjust the output power reference value of the battery, and the actual current value is provided to the modulation loop as the negative feedback signal.

6. The frequency division power control method of the energy storage system and the water electrolysis hydrogen production device according to claim 4 or 5, characterized in that: "Using the above transfer function to control the DC / DC converter in the hydrogen generator to adjust the load power reference value of the hydrogen generator" is specifically: According to the above-mentioned centralized energy storage and water electrolysis hydrogen production device cooperative working frequency division power energy balance model, the output power reference value P is obtained. HE_ref , the power reference value P of the equivalent capacitance of the electrolytic cell EDL HE_ref and the actual voltage U of the equivalent capacitance of the electrolytic cell EDL HE Multiply the inverse of the value and obtain the output current reference value i accordingly. HE_ref Then compare it with the actual current i HE Subtract the current deviation value and introduce the current deviation value into the transfer function G of PI control PI (s) Generates an adjusted control signal value, which is introduced into the transfer function G controlled by the PWM module M (s) generates a pulse signal, and the generated pulse signal introduces the transfer function An actual current value is generated, and a DC / DC converter of the electrolytic cell is controlled by the actual current value to adjust the load power reference value of the electrolytic cell, and the actual current value is provided to the modulation loop as the negative feedback signal.

7. A frequency division power control system for an energy storage system and a water electrolysis hydrogen production device, characterized in that: include: Power reference value acquisition module, collaborative frequency division power energy balance module and DC / DC converter control module, The power reference value acquisition module is used to obtain the corresponding frequency-domain-based battery output power reference value and hydrogen generator load power reference value according to the power relationship in the system in which the energy storage system and the hydrogen generator work together, the second-order low-pass filtering method, the charge state of the energy storage system, and the charge state of the hydrogen generator; The collaborative working frequency division power energy balance module is used to construct a frequency division power energy balance model of the collaborative working of the centralized energy storage and the water electrolysis hydrogen production device according to the working mode of the collaborative working system of the energy storage system and the water electrolysis hydrogen production device in the microgrid, the balance relationship between the input and output power in the microgrid, the charge state of the energy storage system, and the charge state of the hydrogen production machine; The DC / DC converter control module is used to control the DC / DC converter in the energy storage system and the DC / DC converter in the hydrogen generator according to the frequency-division power energy balance model of the coordinated working of the centralized energy storage and the water electrolysis hydrogen production device, the output power reference value of the battery, and the load power reference value of the hydrogen generator, so as to adjust the output power reference value of the battery and the load power reference value of the hydrogen generator.

8. The frequency division power control system of the energy storage system and the water electrolysis hydrogen production device according to claim 7, characterized in that: The power reference value acquisition module is configured to perform the following steps to obtain the output power reference value of the battery and the load power reference value of the hydrogen generator based on the frequency domain: (1) In a system where the energy storage system and the hydrogen generator work together, the power relationship can be expressed as: P V +P bat =P line +P HE (1) Where: P V is the output power of the power generation side; P bat is the output power of the battery; it is positive when the energy element is discharging and negative when it is charging; P line is the grid-connected power, which is positive when discharging to the grid and negative when absorbing grid energy; P HE is the load power of the hydrogen generator; (2) Using the second-order low-pass filtering method, two low-pass filters with different cutoff frequencies are used to filter P V Divided into 3 frequency bands, Time constant T HE <T bat , using a filter with a higher cutoff frequency, the reference value P of the EDL output power of the water electrolysis hydrogen production device is obtained HE_ref The output power of the double-layer capacitor is the reference value of the load power of the hydrogen generator. The intermediate frequency part is removed by using a filter with a lower cut-off frequency and is used as the output power reference value P of the battery. bat_ref , the principle is as follows: The time constant T HE and T bat Need to be determined by actual working status; (3) When the SOC of the energy storage element is close to the threshold, it is necessary to be able to correct the output power reference value to ensure that the SOC is always within a safe range. Therefore, the SOC limit of the energy storage element is added on the basis of the second-order frequency division control. The energy storage element includes the double-layer capacitor of the water electrolysis hydrogen production device and the battery of the energy storage system. The SOC includes the SOC bat and SOC HE ; The remaining capacity SOC of the energy storage element bat and SOC HE Real-time acquisition is performed, and then compared with the corresponding X, X is the basic threshold, amplified by proportion, and fed back to the second-order low-pass filter method. The power reference values ​​of different energy storage elements are: Where: K1 and K2 are proportional magnification coefficients. Further analysis of the above relationship shows that SOC HE When SOC < X, the reference value of the equivalent capacitance output power of the electrolytic cell EDL will decrease. In this case, the continuous decrease of the remaining power can be slowed down; assuming that SOC HE >X, the reference value of the equivalent capacitance output power of the electrolytic cell EDL increases, so the situation of the continuous increase of the remaining power can be slowed down; SOC bat When SOC < X, the reference value of the energy storage battery output power will decrease. In this case, the situation of the continuous decrease of the remaining power can be slowed down; assuming that SOC bat >X, the reference value of the energy storage battery output power increases, so the situation of the continuous increase of the remaining power can be slowed down.

9. The frequency division power control system of the energy storage system and the water electrolysis hydrogen production device according to claim 7, characterized in that: The cooperative working frequency division power energy balance module performs the following steps to realize the construction of the cooperative working frequency division power energy balance model of the centralized energy storage and the water electrolysis hydrogen production device and the control of the DC / DC converter control module: Construct the energy balance model strategy of the following four working modes, where P V is the output power of the power generation side; P HE is the load power of the hydrogen generator; SOC HE SOC is the state of charge of the electrolytic cell EDL capacitor; bat SOC is the state of charge of the battery. bat_max The upper limit of battery SOC; SOC bat_min is the lower limit of battery SOC; SOC HE_max The upper limit of SOC of the electrolytic cell EDL capacitor; SOC HE_min The lower limit of SOC of the electrolytic cell EDL capacitor; Working mode 1 is the normal working mode. At this time, the energy storage element can well smooth the power fluctuation, the microgrid system works normally, and the output power is balanced with the load demand power. V Greater than the load power P HE When the excess power is , the double-layer capacitor of the water electrolysis hydrogen production device and the battery of the energy storage system will absorb it. Otherwise, it will be compensated by the energy storage element. Working mode 2: When SOC HE If the SOC exceeds the set value, bat Normal, because the electrolytic cell EDL capacitor processes the high-frequency part of the power fluctuation, the electrolytic cell EDL capacitor will stop working at this time, which will reduce the energy storage system's ability to suppress high-frequency power fluctuations. Therefore, it is necessary to make SOC HE After returning to a safe range, the mode can be divided into the following four working states according to the balance relationship of output power: SOC HE <SOC HE_min , P V >P HE , no adjustment is made at this time; SOC HE <SOC HE_min , P V <P HE At this time, it is necessary to increase the output of the battery of the energy storage system so that the EDL capacitor of the electrolyzer absorbs the excess power to increase the SOC HE , back to normal; SOC HE >SOC HE_max , P V <P HE , no adjustment is made at this time; SOC HE >SOC HE_max , P V >P HE , using the battery charging in the energy storage system to absorb the remaining power and discharge the electrolyzer EDL capacitor to a certain extent; Working mode 3: When SOC bat If the SOC exceeds the set normal value, HE Under normal circumstances, since the energy storage system processes the low-frequency part of the power fluctuation, if the energy storage system stops working, the ability to suppress power fluctuation will be weakened for a long time. In addition, because the battery capacity of the energy storage system is much larger than the electrolytic cell EDL capacitor, it is difficult to control the output of the electrolytic cell EDL capacitor to meet the overall needs of the system. At this time, it can also be divided into three working states: SOC bat <SOC bat_min , P V >P HE , no adjustment is made at this time; SOC bat <SOC bat_min , P V <P HE , at this time, the electrolytic cell power needs to be adjusted, for example, the electrolytic cell power is adjusted according to the process in step S300; SOC bat >SOC bat_max , P V <P HE , no adjustment is made at this time; SOC bat >SOC bat_max , P V >P HE , at this time, adjust the output power of the power generation side; Working mode 4: When the SOC of the energy storage elements exceeds the set value, the working state can be divided into the following 8 types: SOC bat >SOC bat_max , SOC HE >SOC HE_max , P V <P HE , no adjustment is made at this time; SOC bat >SOC bat_max , SOC HE >SOC HE_max , P V >P HE At this time, the control strategy and the "SOC bat >SOC bat_max , P V >P HE , at this time adjust the output power of the power generation side; "same; SOC bat <SOC bat_min , SOC HE <SOC HE_min , P V >P HE , no adjustment is made at this time; SOC bat <SOC bat_min , SOC HE <SOC HE_min , P V <P HE At this time, the control strategy and the "SOC bat <SOC bat_min , P V <P HE , at this time, the electrolytic cell power needs to be adjusted; "same; SOC bat >SOC bat_max , SOC HE <SOC HE_min , P V <P HE At this time, the control strategy and the "SOC HE <SOC HE_min , P V <P HE At this time, it is necessary to increase the output of the battery of the energy storage system so that the EDL capacitor of the electrolyzer absorbs the excess power to increase the SOC HE , back to normal;”Same; SOC bat >SOC bat_max , SOC HE <SOC HE_min , P V >P HE At this time, the control strategy and the "SOC bat >SOC bat_max , P V >P HE , at this time, adjust the output power of the power generation side to be the same; SOC bat <SOC bat_min , SOC HE >SOC HE_max , P V >P HE At this time, the control strategy and the "SOC HE >SOC HE_max , P V >P HE , using the battery charging in the energy storage system to absorb the remaining power and discharge the electrolyzer EDL capacitor to a certain extent” is the same; SOC bat <SOC bat_min , SOC HE >SOC HE_max , P V <P HE At this time, the control strategy and the "SOC bat <SOC bat_min , P V <P HE , at this time, the electrolytic cell power needs to be adjusted; "same.

10. The frequency division power control system of the energy storage system and the water electrolysis hydrogen production device according to claim 7, characterized in that: The DC / DC converter control module performs the following steps to adjust the output power reference value of the battery and the load power reference value of the hydrogen generator: When the circuit works in the Boost state, T1 is turned off and T2 is working. The discharge of the energy storage element is achieved by modulating the duty cycle D of T2. E is the equivalent voltage source on the energy storage side; I is the current flowing through the inductor; R is the resistance on the load side; C is the capacitance on the load side; L is the inductor on the energy storage side; the energy flow direction is selected as the reference direction of the current; let the duty cycle of T2 be D, D=T on / T, where T on is the conduction time of tube T2, U0 is the terminal voltage on the energy storage side, U dc is the output DC side voltage; When the T2 tube is in T on When the time period is , the current I is used as the state variable, and the state equation can be expressed as: When the T2 tube is in T off When the time period is , the following state equation is obtained: The following state equation is obtained by using the average state method: By transforming formula (6), we can get the following formula: The small signal transfer function in Boost mode is obtained by frequency domain transformation of equations (7) and (8): Among them, in Boost mode, is the transfer function of the DC bus voltage to the duty cycle, It is the transfer function of DC bus voltage to inductor current. Both can reflect the influence of duty cycle and inductor current change on DC bus voltage. I-D(s) Based on the transfer function Transfer Function Generate a corresponding current signal and provide the current signal to the modulation loop and the DC / DC converter of the energy storage system; G I-D(s) for The transfer function of the controller; When the circuit works in the Buck state, T1 is working and T2 is off. We only need to control the duty cycle D' of T1. The following formula can be derived: In the Buck state, the duty cycle of T1 is D', and its small signal transfer function expression is: G M (s)=1 (17) Among them, in Buck mode, is the transfer function of output voltage to duty cycle, reflecting the effect of duty cycle change on output voltage; G I_D' (s) is the transfer function of the inductor current to the duty cycle, G PI (s) is the transfer function of the PI controller; G M (s) is the transfer function of the modulation loop; The above transfer function is used to control the DC / DC converter in the energy storage system and the DC / DC converter in the hydrogen generator to adjust the output power reference value of the battery and the load power reference value of the hydrogen generator; Among them: "Using the above transfer function to control the DC / DC converter in the energy storage system and the DC / DC converter in the hydrogen generator to adjust the output power reference value of the battery and the load power reference value of the hydrogen generator" is specifically: According to the above-mentioned centralized energy storage and water electrolysis hydrogen production device cooperative working frequency division power energy balance model, the output power reference value P is obtained. bat_ref Since the output DC voltage is constant, the power reference value of the battery and the actual battery voltage U bat Multiply the inverse of the value and obtain the output current reference value i accordingly. bat_ref Then compare it with the actual current i bat Subtract the current deviation value and introduce the current deviation value into the transfer function G of PI control PI (s) Generates an adjusted control signal value, which is introduced into the transfer function G controlled by the PWM module M (s) generates a pulse signal, and the generated pulse signal introduces the transfer function Generate an actual current value, use the actual current value to control the DC / DC converter of the energy storage system to adjust the output power reference value of the battery, and provide the actual current value as the negative feedback signal to the modulation loop; According to the above-mentioned centralized energy storage and water electrolysis hydrogen production device cooperative working frequency division power energy balance model, the output power reference value P is obtained. HE_ref , the power reference value P of the equivalent capacitance of the electrolytic cell EDL HE_ref and the actual voltage U of the equivalent capacitance of the electrolytic cell EDL HE Multiply the inverse of the value and obtain the output current reference value i accordingly. HE_ref Then compare it with the actual current i HE Subtract the current deviation value and introduce the current deviation value into the transfer function G of PI control PI (s) Generates an adjusted control signal value, which is introduced into the transfer function G controlled by the PWM module M (s) generates a pulse signal, and the generated pulse signal introduces the transfer function An actual current value is generated, and a DC / DC converter of the electrolytic cell is controlled by the actual current value to adjust the load power reference value of the electrolytic cell, and the actual current value is provided to the modulation loop as the negative feedback signal.

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