CN-122026362-A - Cooperative control method and device for electrolytic hydrogen production hybrid rectification system

Abstract

The invention discloses a cooperative control method and device of an electrolytic hydrogen production hybrid rectification system, which comprises the steps of collecting three-phase voltage, three-phase current and voltage of a direct current bus on a power grid side, extracting harmonic current components and reactive current components on the power grid side based on the three-phase voltage and the three-phase current, decomposing total power required by an electrolytic cell into target fundamental wave power distributed to a main power unit and target compensation power distributed to a compensation unit, generating a duty ratio instruction according to the target fundamental wave power and the voltage of the direct current bus, adjusting actual fundamental wave power output by the main power unit to the direct current bus to enable the actual fundamental wave power to be matched with the target fundamental wave power, and generating a total current reference instruction according to the target compensation power, the harmonic current components and the reactive current components to control the compensation unit to output compensation current to the direct current bus. The invention can synchronously realize stable supply of fundamental wave power, rapid compensation of power fluctuation, harmonic suppression and reactive compensation of a power grid, and improves the efficiency and stability of the system.

Inventors

• LIU JUN
• WANG GUANGCHUN
• LEI ZHENYUAN
• ZHOU ZUXU
• HAN WENJIE
• WANG JIE

Assignees

• 中电建新能源集团股份有限公司

Dates

Publication Date

20260512

Application Date

20260410

Claims (20)

1. 1. The cooperative control method of the electrolytic hydrogen production hybrid rectification system is characterized in that the electrolytic hydrogen production hybrid rectification system comprises a main power unit and a compensation unit, wherein the output end of the main power unit and the output end of the compensation unit are both connected to a direct current bus for supplying power to an electrolytic tank, and the method comprises the following steps: collecting three-phase voltage and three-phase current of a power grid side and voltage of the direct current bus, and extracting harmonic current components and reactive current components of the power grid side based on the three-phase voltage and the three-phase current; The total power required by the electrolytic tank is obtained, and the total power is decomposed into target fundamental wave power distributed to the main power unit and target compensation power distributed to the compensation unit; Generating a duty ratio instruction according to the target fundamental wave power and the voltage of the direct current bus so as to adjust the actual fundamental wave power output by the main power unit to the direct current bus and enable the actual fundamental wave power to be matched with the target fundamental wave power; And generating a total current reference instruction according to the target compensation power, the harmonic current component and the reactive current component to control the compensation unit to output compensation current to the direct current bus, wherein the compensation current is used for responding to a power fluctuation part in the target compensation power to realize power fluctuation compensation, and is used for counteracting the harmonic current component to realize harmonic suppression and counteracting the reactive current component to realize reactive compensation.
2. 2. The cooperative control method of claim 1, wherein the electrolytic hydrogen production hybrid rectifying system further comprises an integrated multi-winding transformer, the integrated multi-winding transformer having one input winding and at least three low-voltage output windings, the input winding being connected to a grid side for transforming the alternating current on the grid side and then distributing the alternating current to each low-voltage output winding; The input end of the main power unit is connected with a first low-voltage output winding and a second low-voltage output winding of the integrated multi-winding transformer and is used for rectifying the transformed alternating current into direct current and outputting the direct current to a direct current bus, and the main power unit comprises at least two 6-pulse diode rectifier bridges and a direct current converter connected with the output ends of the two 6-pulse diode rectifier bridges in series; the input end of the compensation unit is connected with a third low-voltage output winding of the integrated multi-winding transformer and is used for rectifying the transformed alternating current into direct current and providing compensation current for the direct current bus, and the compensation unit comprises a rectifier; The duty ratio instruction is used for regulating the on-off state of a switching tube of the direct current converter so as to regulate the actual fundamental wave power output by the main power unit to the direct current bus, and the total current reference instruction is used for controlling the rectifier to output compensation current to the direct current bus.
3. 3. The cooperative control method according to claim 1, wherein the extracting harmonic current component and reactive current component on the grid side based on the three-phase voltage and three-phase current includes: transforming the three-phase voltage and the three-phase current into an alpha beta static coordinate system to obtain an alpha-axis voltage component, a beta-axis voltage component, an alpha-axis current component and a beta-axis current component; Calculating instantaneous active power and instantaneous reactive power according to the voltage component of the alpha axis, the voltage component of the beta axis, the current component of the alpha axis and the current component of the beta axis; Extracting a direct current component of the instantaneous active power and a direct current component of the instantaneous reactive power through a low-pass filter; Subtracting the direct current component of the instantaneous active power from the instantaneous active power to obtain an alternating current component of the instantaneous active power, and subtracting the direct current component of the instantaneous reactive power from the instantaneous reactive power to obtain an alternating current component of the instantaneous reactive power; performing two-time inverse transformation on the alternating current component of the instantaneous active power and the alternating current component of the instantaneous reactive power to obtain a harmonic current component; The reactive current component is calculated from the direct current component of the instantaneous reactive power.
4. 4. A cooperative control method according to claim 3, wherein the performing the inverse transformation on the ac component of the instantaneous active power and the ac component of the instantaneous reactive power twice to obtain the harmonic current component comprises: the alternating current component of the instantaneous active power and the alternating current component of the instantaneous reactive power are subjected to first inverse transformation to obtain an alpha-axis harmonic current component and a beta-axis harmonic current component under an alpha beta static coordinate system; The harmonic current component of the alpha axis and the harmonic current component of the beta axis are subjected to second inverse transformation to obtain three-phase harmonic current components, and instantaneous values of the three-phase harmonic current components are taken as the harmonic current components; the calculating reactive current component according to the direct current component of the instantaneous reactive power comprises the following steps: determining a reactive current component according to the ratio of the direct current component of the instantaneous reactive power to the grid voltage amplitude, wherein the grid voltage amplitude is determined according to the three-phase voltage of the grid side; Wherein the first inverse transformation is a transformation of the amount of current from the amount of power to an αβ stationary coordinate system and the second inverse transformation is a Clarke inverse transformation from the αβ stationary coordinate system to an abc three-phase coordinate system.
5. 5. The cooperative control method according to claim 1, characterized in that the decomposing the total power into a target fundamental power allocated to the main power unit and a target compensation power allocated to the compensation unit includes: The total power is subjected to low-pass filtering, and the slow-change direct current component obtained after filtering is used as the target fundamental wave power which is the main power component for hydrogen production and power supply of the electrolytic cell; taking the difference value between the total power and the target fundamental wave power as a power fluctuation component; Generating a harmonic compensation component according to the harmonic current component, and generating a reactive compensation component according to the reactive current component; And synthesizing the power fluctuation component, the harmonic compensation component and the reactive compensation component into the target compensation power, wherein the target compensation power is an auxiliary compensation power component for hydrogen production and power supply of the electrolytic cell.
6. 6. The cooperative control method according to claim 1, wherein the generating a duty command from the target fundamental wave power and the voltage of the dc bus includes: Determining a target output current of a direct current converter in a main power unit according to the ratio of the target fundamental wave power to the voltage of the direct current bus; Collecting the actual output current of a direct current converter in a main power unit, and calculating a first current error between the target output current and the actual output current of the direct current converter; Calculating a duty ratio adjustment amount according to the first current error, a first proportional coefficient and a first integral coefficient of a regulator, wherein the first proportional coefficient and the first integral coefficient are set according to an inductance value, a switching frequency and an expected current loop cut-off frequency of the direct current converter; determining a feedforward duty ratio according to the ratio of the voltage of the direct current bus to the average voltage output by two 6-pulse diode rectifier bridges in the main power unit; And superposing the duty cycle adjustment amount and the feedforward duty cycle to obtain an initial duty cycle, and limiting the initial duty cycle within a preset interval to generate a duty cycle instruction.
7. 7. The cooperative control method according to claim 6, wherein the calculating the duty cycle adjustment amount according to the first current error and a preset first proportional coefficient, a first integral coefficient includes: The duty cycle adjustment is calculated according to the following formula: Wherein, the Is the duty cycle adjustment amount; is a first proportional system; E I is the first current error.
8. 8. The cooperative control method according to claim 1, wherein the generating a total current reference command according to the target compensation power, the harmonic current component, and the reactive current component includes: generating an active current instruction of a d axis under a dq rotating coordinate system according to the power fluctuation component in the target compensation power; taking the opposite phase of the reactive current component to generate a q-axis reactive current instruction under a dq rotating coordinate system; taking the opposite phases of the harmonic current components to generate a three-phase harmonic current instruction under an abc three-phase coordinate system; and the active current instruction and the reactive current instruction are overlapped with the three-phase harmonic current instruction after being subjected to third inverse transformation and second inverse transformation in sequence, so that a total current reference instruction under an abc three-phase coordinate system is synthesized, and the third inverse transformation is Park inverse transformation from a dq rotating coordinate system to an alpha beta static coordinate system.
9. 9. The cooperative control method according to claim 8, wherein the generating an active current command of the d-axis in the dq rotation coordinate system according to the power fluctuation component in the target compensation power includes: generating an active current command of a d-axis in a dq rotation coordinate system according to the following formula: Wherein, the The power supply system is characterized in that the power supply system is an active current instruction of a d-axis under a dq rotating coordinate system, P wave is a power fluctuation component, U d is power grid voltage of the d-axis under the dq rotating coordinate system, and the value is equal to the power grid voltage amplitude; the active current instruction and the reactive current instruction are overlapped with the three-phase harmonic current instruction after being subjected to third inverse transformation and second inverse transformation in sequence to be synthesized into a total current reference instruction under an abc three-phase coordinate system, and the method comprises the following steps: The active current instruction and the reactive current instruction are subjected to third inverse transformation to obtain an alpha-axis fundamental current instruction and a beta-axis fundamental current instruction under an alpha beta static coordinate system; The fundamental wave current command of the alpha axis and the fundamental wave current command of the beta axis are subjected to second inverse transformation to obtain a three-phase fundamental wave current command under an abc three-phase coordinate system; And superposing the three-phase fundamental wave current instruction and the three-phase harmonic current instruction to obtain a total current reference instruction under an abc three-phase coordinate system.
10. 10. The cooperative control method according to claim 1, wherein the controlling the compensation unit to output a compensation current to the dc bus includes: calculating a voltage feedforward term based on the three-phase voltage and the three-phase current at the power grid side and the alternating-current side inductance of the rectifier in the compensation unit; collecting actual output current of the alternating current side of a rectifier in a compensation unit, and calculating a second current error between the total reference current in the total current reference instruction and the actual output current of the alternating current side of the rectifier; calculating a current feedback correction amount according to the second current error, a second proportional coefficient and a second integral coefficient of the regulator, wherein the second proportional coefficient and the second integral coefficient are set according to the inductance value, the switching frequency and the expected cut-off frequency of the current loop of the rectifier; Adding the voltage feedforward term and the current feedback correction amount to obtain a pulse width modulation wave signal; And controlling the on-off of a switching tube of a rectifier in the compensation unit according to the pulse width modulation wave signal so as to enable the compensation unit to output compensation current to the direct current bus.
11. 11. The cooperative control method as claimed in claim 1, further comprising: applying rate limitation to the target fundamental wave power to enable the change rate of the target fundamental wave power to be smaller than a preset rate threshold value, and not applying rate limitation to the target compensation power; When the sudden change of the total power is detected, the sudden change component is distributed to the target compensation power, so that the compensation unit generates corresponding compensation current according to the sudden change component to compensate for the power deficiency, and meanwhile, the actual fundamental wave power of the main power unit approaches to the target fundamental wave power according to a limited speed until the sudden change of the total power is stopped.
12. 12. The cooperative control method as claimed in claim 1, further comprising: Collecting system operation data, an inductance ripple current of a direct current converter, a ripple current of an alternating current side inductance of a compensation unit rectifier and operation parameters of each power device in real time, wherein the system operation data comprises total output power, direct current bus voltage, actual output power of a main power unit and actual output power of the compensation unit; According to the actual output power of the power unit and the voltage of the direct current bus, calculating to obtain the average conduction current of a 6-pulse diode rectifier bridge in the main power unit, and calculating to obtain the first effective conduction current of a full-control switching tube in the direct current converter by combining the inductance ripple current of the direct current converter; calculating to obtain the output average current of the compensation unit according to the actual output power of the compensation unit and the DC bus voltage, and calculating to obtain the second effective conduction current of the full-control switching tube in the rectifier by combining the ripple current of the inductance of the alternating current side of the rectifier of the compensation unit; Inputting the collected operation parameters of each power device, the average conducting current, the first effective conducting current and the second effective conducting current into a preset power device loss model, and outputting the total loss of a system, wherein the total loss of the system is the sum of the main power unit loss and the compensation unit loss; determining an optimal power distribution coefficient according to the total loss of the system, the total output power and the direct current bus voltage, wherein the optimal power distribution coefficient is used for dynamically adjusting the distribution proportion of the target fundamental wave power and the target compensation power so that the total loss of the system is smaller than a preset loss threshold value; The operation parameters of the power devices comprise forward conduction voltage drop of a rectifier diode in a 6-pulse diode rectifier bridge, first conduction voltage drop, first switching frequency, first single switching loss and first single switching loss of a full-control switching tube in a direct-current converter, second conduction voltage drop, second switching frequency, second single switching loss and second single switching loss of the full-control switching tube in the rectifier.
13. 13. The cooperative control method of claim 12, wherein the power device loss model includes a main power unit loss submodel and a compensation unit loss submodel, the main power unit loss submodel includes a rectifier diode conduction loss model of a 6-pulse diode rectifier bridge, a first fully-controlled switching tube conduction loss model of a dc converter, and a first switching loss model, and the compensation unit loss submodel includes a second fully-controlled switching tube conduction loss model of the rectifier and a second switching loss model; wherein, the rectifier diode conduction loss model includes: Wherein P D-cond is the total conduction loss of all 6-pulse diode rectifier bridges, n is the total number of rectifier diodes of all 6-pulse diode rectifier bridges, V F is the forward conduction voltage drop of the rectifier diodes in the 6-pulse diode rectifier bridges, and I D-avg is the average conduction current; the first fully-controlled switching tube conduction loss model comprises: Wherein P S-cond is the total conduction loss of the DC converter, m is the total number of the full-control switching tubes of the DC converter, V S-on is the first conduction voltage drop of the full-control switching tubes in the DC converter, and I S-rms is the first effective conduction current; The first switching loss model includes: wherein P S-sw is the total switching loss of the DC converter, k is the bridge arm number of the DC converter, E on1 is the first single turn-on loss, E off1 is the first single turn-off loss, and f sw1 is the first switching frequency; The main power unit loss is the sum of the total conduction loss of all 6 pulse wave diode rectifier bridges, the total conduction loss of the direct current converter and the total switching loss of the direct current converter.
14. 14. The cooperative control method of claim 13, wherein the second fully-controlled switching tube conduction loss model includes: Wherein, P IGBT-cond is the total conduction loss of the rectifier, and P is the total number of the full-control switch tubes of the rectifier; The second conduction voltage drop is the full control type switch tube in the rectifier; Is a second effective conduction current; the second switching loss model includes: Wherein P S-sw is the total switching loss of the rectifier, q is the bridge arm number of the rectifier, E on2 is the second single turn-on loss, E off2 is the second single turn-off loss, and f sw2 is the second switching frequency; the compensation unit loss is the sum of the total conduction loss of the rectifier and the total switching loss of the rectifier.
15. 15. The cooperative control method as claimed in claim 12, wherein the determining an optimal power distribution coefficient according to the total system loss and total output power includes: setting an initial power distribution coefficient, and determining a target fundamental wave power distribution value and a target compensation power distribution value before disturbance based on the initial power distribution coefficient and the total output power; Applying preset disturbance by taking the initial power distribution coefficient as a starting point to obtain a disturbed power distribution coefficient, and determining a disturbed target fundamental wave power distribution value and a target compensation power distribution value based on the disturbed power distribution coefficient and the total output power; Inputting the actual output power of the main power unit, the actual output power of the compensation unit and the operation parameters of the power devices corresponding to the target fundamental wave power distribution value and the target compensation power distribution value before disturbance to a preset power device loss model, and outputting the total loss of the system before disturbance; Inputting the actual output power of the main power unit, the actual output power of the compensation unit and the operation parameters of the power devices corresponding to the disturbed target fundamental wave power distribution value and the target compensation power distribution value into a preset power device loss model, and outputting the total loss of the disturbed system; Calculating the difference value between the total loss of the system after disturbance and the total loss of the system before disturbance to obtain the total loss variation of the system; If the total loss variation of the system is larger than zero, the total loss is increased in the disturbance direction, and the disturbance is applied in the opposite direction; Repeating the steps of applying disturbance, calculating the total loss of the system before and after the disturbance and judging the direction until the total loss variation of the system converges to a preset variation threshold value, and taking the power distribution coefficient after the disturbance as the optimal power distribution coefficient.
16. 16. A cooperative control system, comprising: An integrated multi-winding transformer having one input winding and at least three low voltage output windings; The input end of the main power unit is connected with a first low-voltage output winding and a second low-voltage output winding of the integrated multi-winding transformer and is used for rectifying the transformed alternating current into direct current and outputting the direct current to a direct current bus, and the main power unit comprises at least two 6-pulse diode rectifier bridges and a direct current converter connected with the output ends of the two 6-pulse diode rectifier bridges in series; The input end of the compensation unit is connected with the third low-voltage output winding of the integrated multi-winding transformer and is used for rectifying the transformed alternating current into direct current and providing compensation current for the direct current bus, the compensation unit comprises a rectifier, and A cooperative controller for executing the cooperative control method according to any one of claims 1 to 15.
17. 17. The utility model provides a cooperative control device of electrolysis hydrogen manufacturing hybrid rectification system, its characterized in that, electrolysis hydrogen manufacturing hybrid rectification system includes main power unit and compensation unit, the output of main power unit and the output of compensation unit all are connected to the direct current busbar that supplies power for the electrolysis trough, and the device includes: the extraction module is used for collecting three-phase voltage and three-phase current on the power grid side and the voltage of the direct current bus, and extracting harmonic current components and reactive current components on the power grid side based on the three-phase voltage and the three-phase current; The decomposition module is used for obtaining the total power required by the electrolytic tank and decomposing the total power into target fundamental wave power distributed to the main power unit and target compensation power distributed to the compensation unit; The main power unit adjusting module is used for generating a duty ratio instruction according to the target fundamental wave power and the voltage of the direct current bus so as to adjust the actual fundamental wave power output by the main power unit to the direct current bus and enable the actual fundamental wave power to be matched with the target fundamental wave power; And the compensation unit control module is used for generating a total current reference instruction according to the target compensation power, the harmonic current component and the reactive current component so as to control the compensation unit to output compensation current to the direct current bus, wherein the compensation current is used for responding to a power fluctuation part in the target compensation power to realize power fluctuation compensation, and is used for counteracting the harmonic current component to realize harmonic suppression and counteracting the reactive current component to realize reactive compensation.
18. 18. An electronic device, comprising: A memory and a processor in communication with each other, the memory having stored therein computer instructions which, upon execution, cause the processor to perform the steps of the method of any of claims 1 to 15.
19. 19. A computer storage medium storing computer program instructions which, when executed, implement the steps of the method of any one of claims 1 to 15.
20. 20. A computer program product comprising a computer program which, when executed by a processor, implements the steps of the method of any one of claims 1 to 15.

Description

Cooperative control method and device for electrolytic hydrogen production hybrid rectification system Technical Field The invention relates to the technical field of power electronics, in particular to a cooperative control method and device of an electrolytic hydrogen production hybrid rectification system. Background With the rapid development of renewable energy power generation, water electrolysis hydrogen production is receiving a great deal of attention as an important technical route for green hydrogen production. The high-power electrolytic hydrogen production hybrid rectification system provides requirements of high power level, high power quality, high dynamic response and high reliability for a power supply. The existing high-power electrolytic hydrogen production hybrid rectifying system adopts diode and IGBT (insulated gate bipolar transistor) hybrid rectification, but has the problems of harmonic pollution, reactive power loss, incapability of quick compensation of power fluctuation and insufficient stability of a direct current bus, so that the operation efficiency of an electrolytic tank is reduced, and the service life of the electrolytic tank is shortened. In view of the above problems, no effective solution has been proposed at present. Disclosure of Invention The embodiment of the specification provides a cooperative control method and device of an electrolytic hydrogen production hybrid rectification system, which are used for solving the problems that harmonic pollution, reactive power loss, power fluctuation cannot be compensated rapidly and the stability of a direct current bus is insufficient in the existing electrolytic hydrogen production hybrid rectification system. In a first aspect, embodiments of the present disclosure provide a cooperative control method of an electrolytic hydrogen production hybrid rectifying system, where the electrolytic hydrogen production hybrid rectifying system includes a main power unit and a compensation unit, and an output end of the main power unit and an output end of the compensation unit are both connected to a dc bus for supplying power to an electrolytic cell, and the method includes: collecting three-phase voltage and three-phase current of a power grid side and voltage of the direct current bus, and extracting harmonic current components and reactive current components of the power grid side based on the three-phase voltage and the three-phase current; The total power required by the electrolytic tank is obtained, and the total power is decomposed into target fundamental wave power distributed to the main power unit and target compensation power distributed to the compensation unit; Generating a duty ratio instruction according to the target fundamental wave power and the voltage of the direct current bus so as to adjust the actual fundamental wave power output by the main power unit to the direct current bus and enable the actual fundamental wave power to be matched with the target fundamental wave power; And generating a total current reference instruction according to the target compensation power, the harmonic current component and the reactive current component to control the compensation unit to output compensation current to the direct current bus, wherein the compensation current is used for responding to a power fluctuation part in the target compensation power to realize power fluctuation compensation, and is used for counteracting the harmonic current component to realize harmonic suppression and counteracting the reactive current component to realize reactive compensation. In some embodiments, the electrolytic hydrogen production hybrid rectification system further comprises an integrated multi-winding transformer, wherein the integrated multi-winding transformer is provided with one input winding and at least three low-voltage output windings, the input winding is connected to the power grid side and is used for transforming the alternating current of the power grid side and then distributing the alternating current to the low-voltage output windings; The input end of the main power unit is connected with a first low-voltage output winding and a second low-voltage output winding of the integrated multi-winding transformer and is used for rectifying the transformed alternating current into direct current and outputting the direct current to a direct current bus, and the main power unit comprises at least two 6-pulse diode rectifier bridges and a direct current converter connected with the output ends of the two 6-pulse diode rectifier bridges in series; the input end of the compensation unit is connected with a third low-voltage output winding of the integrated multi-winding transformer and is used for rectifying the transformed alternating current into direct current and providing compensation current for the direct current bus, and the compensation unit comprises a rectifier; The duty ratio instruction is used for regulating t