Hydrogen production power supply parallel operation control method and system

Abstract

The invention discloses a hydrogen production power supply parallel operation control method and system, and the method is used for the parallel operation control of a plurality of hydrogen production power supply modules, and comprises the steps: collecting an alternating current signal of each hydrogen production power supply module, carrying out the conversion of a three-phase static coordinate system to a rotating coordinate system of the alternating current signal, and obtaining an output current component; comparing the output current component with a preset reference value to obtain a current deviation value; controlling the current deviation value based on a proportional-integral (PI) adjustment algorithm to obtain an output control signal; and integrating the output control signals based on a space vector pulse width modulation (SVPWM) algorithm, and generating a control signal. According to the invention, the calculated current deviation value is converted into the output control signal, and the output control signal is integrated to generate the corresponding control signal, so that the control signal can be utilized to adjust the electric energy output to suppress the zero-sequence circulating current, the problem of circulating current interference is effectively solved, and the stability of the hydrogen production power supply system is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power supplies, and in particular to a method and system for controlling parallel operation of hydrogen production power supplies. Background Art

[0002] The existing hydrogen production power supply design has difficulty in achieving an effective balance between controlling costs and optimizing system performance, especially in large-scale hydrogen production scenarios. In order to adapt to the application requirements of large-scale electrolyzers (large-scale electrolyzers refer to electrolyzers with hydrogen production reaching a high standard, usually measured in standard cubic meters (i.e., standard cubic meters) per hour), existing hydrogen production systems generally adopt a multi-module or multi-machine parallel operation mode. However, in a parallel system, due to problems such as inconsistent parameters and uncoordinated control strategies between the power modules, circulation phenomena are very likely to occur. In summary, the existing hydrogen production power supply system has a poor effect in suppressing circulation under parallel operation conditions. Summary of the Invention

[0003] The embodiments of the present invention provide a method and system for controlling parallel operation of a hydrogen production power supply, aiming to solve the problem in the prior art that the circulating current suppression effect of the hydrogen production power supply system under parallel operation conditions is poor.

[0004] In a first aspect, an embodiment of the present invention provides a method for controlling a hydrogen production power supply in parallel, for controlling a plurality of hydrogen production power supply modules in parallel, comprising:

[0005] collecting the AC current signal of each of the hydrogen production power modules, and transforming the AC current signal from a three-phase stationary coordinate system to a rotating coordinate system to obtain an output current component;

[0006] Comparing the output current component with a preset reference value to obtain a current deviation value;

[0007] The current deviation value is controlled based on a proportional-integral (PI) regulation algorithm to obtain an output control signal; wherein the output control signal at least includes a zero-sequence control signal;

[0008] The output control signal is integrated based on a Space Vector Pulse Width Modulation (SVPWM) algorithm to generate a control signal; wherein the control signal is used to achieve electric energy output to suppress zero-sequence circulating current.

[0009] In the second aspect, an embodiment of the present invention provides a hydrogen production power supply parallel control system that adopts the hydrogen production power supply parallel control method as described above, including: a host computer, a parallel controller and multiple hydrogen production power supply modules, the hydrogen production power supply modules including a digital signal controller, a power control unit and a power module connected in sequence; the host computer is communicatively connected to the parallel controller; the parallel controller is communicatively connected to each of the digital signal controllers respectively; the parallel controller is used to handle user interaction, communication protocol conversion and parallel power distribution.

[0010] An embodiment of the present invention provides a method for controlling a hydrogen production power supply in parallel, which is used to control a plurality of hydrogen production power supply modules in parallel, including: collecting the AC current signal of each hydrogen production power supply module, transforming the AC current signal from a three-phase stationary coordinate system to a rotating coordinate system to obtain an output current component; comparing the output current component with a preset reference value to obtain a current deviation value; controlling the current deviation value based on a PI adjustment algorithm to obtain an output control signal; integrating the output control signal based on an SVPWM algorithm and generating a control signal. The present invention converts the calculated current deviation value into an output control signal, and then integrates the output control signal to generate a corresponding control signal. In this way, the control signal can be used to adjust the power output to suppress the zero-sequence circulating current, effectively solving the circulating current interference problem, and improving the stability of the hydrogen production power supply system.

[0011] An embodiment of the present invention further provides a hydrogen production power supply parallel control system that adopts the above-mentioned hydrogen production power supply parallel control method, which also has the above-mentioned beneficial effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0013] Figure 1 A schematic flow chart of a method for controlling parallel operation of a hydrogen production power supply provided by an embodiment of the present invention;

[0014] Figure 2 A schematic diagram of a carrier synchronization process according to an embodiment of the present invention;

[0015] Figure 3 A topology diagram of the parallel control of hydrogen production power supplies provided in an embodiment of the present invention;

[0016] Figure 4 An equivalent circuit diagram of the parallel control of the hydrogen production power supply provided by an embodiment of the present invention;

[0017] Figure 5A block diagram of a zero-sequence current control algorithm provided by an embodiment of the present invention;

[0018] Figure 6 A schematic structural diagram of a hydrogen production power supply parallel control system provided by an embodiment of the present invention;

[0019] Figure 7 A schematic diagram of the structure of a controller motherboard provided in an embodiment of the present invention;

[0020] Figure 8 This is a circuit topology diagram of the hydrogen production power module provided in an embodiment of the present invention.

[0021] Description of the symbols in the figure:

[0022] 1. Host computer; 2. Parallel controller; 3. Digital signal controller; 4. Power control unit; 5. Power module; 6. Hydrogen production power module; 7. First daughter board; 8. First mother board. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0024] It will be understood that when used in this specification and the appended claims, the terms “comprises” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0025] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the present invention. As used in the specification and appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0026] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0027] See below Figure 1 , Figure 1 A flow chart of a method for controlling parallel operation of a hydrogen production power supply provided in an embodiment of the present invention is provided, which is used to control parallel operation of multiple hydrogen production power supply modules, and specifically includes steps S101 to S104.

[0028] S101, collecting the AC current signal of each hydrogen production power module, transforming the AC current signal from a three-phase stationary coordinate system to a rotating coordinate system, and obtaining an output current component;

[0029] S102, comparing the output current component with a preset reference value to obtain a current deviation value;

[0030] S103, controlling the current deviation value based on a PI regulation algorithm to obtain an output control signal; wherein the output control signal at least includes a zero-sequence control signal;

[0031] In one embodiment, the output control signal further includes a direct-axis control signal and a quadrature-axis control signal.

[0032] S104 , integrating the output control signals based on the SVPWM algorithm and generating a control signal; wherein the control signal is used to achieve power output to suppress zero-sequence circulating current.

[0033] Combine Figure 2 As shown, in one embodiment, the method for controlling the parallel operation of hydrogen production power supplies further includes:

[0034] When the hydrogen production power supply parallel system is started, it is determined whether the current hydrogen production power supply module is a master hydrogen production power supply module or a slave hydrogen production power supply module;

[0035] When it is determined that the master hydrogen-making power supply module is the master, it is determined whether a PWM synchronous clock signal is received, and whether the PWM synchronous clock signal is consistent with the preset master signal. If they are consistent, the PWM synchronous clock signal is output, and the PWM synchronous clock signal is converted into an electrical signal and sent to the carrier control circuit of the slave hydrogen-making power supply module; if the PWM synchronous clock signal is not received or the PWM synchronous clock signal is inconsistent with the preset master signal, a carrier abnormality alarm is output;

[0036] When it is determined to be a slave hydrogen-making power supply module, it is determined whether the PWM synchronous clock signal sent by the master hydrogen-making power supply module is received. If the PWM synchronous clock signal is not received, a carrier abnormality alarm is output; if the PWM synchronous clock signal is received, the zero-sequence circulating current is suppressed according to the PWM synchronous clock signal.

[0037] In this embodiment, when the hydrogen production power supply parallel system is started, module identity identification is first performed to determine whether the current hydrogen production power supply module is a master hydrogen production power supply module or a slave hydrogen production power supply module. For devices determined to be master hydrogen production power supply modules, further detection is performed to determine whether a synchronization pulse signal from the upper-level carrier control circuit has been received. At the same time, verification is performed to determine whether a PWM synchronization clock signal has been issued by the local digital signal processor (DSP). It is also necessary to determine whether the received PWM synchronization clock signal is consistent with the preset master synchronization signal parameters (such as frequency, phase, pulse width, etc.). If the determination result is consistent, the received synchronization signal is processed as a valid PWM synchronization clock signal and sent to the carrier control circuit of each slave hydrogen production power supply module in the form of an electrical signal via the optoelectronic conversion interface to achieve unified synchronization of the carrier signal and ensure the timing consistency of the PWM signals of each module in the entire parallel system. If the synchronization signal is not received during the detection process, or the received PWM synchronization signal does not match the preset master signal parameters, the exception handling logic will be triggered and a "carrier abnormality alarm" message will be output to prompt the user to check the communication link or the status of the main controller.

[0038] Upon startup, a device identified as a slave hydrogen-generating power module will first determine whether it has received the PWM synchronization clock signal transmitted by the master hydrogen-generating power module via the optical fiber communication link. If a valid synchronization signal is received, the slave hydrogen-generating power module will adjust the phase and frequency of its local PWM carrier control circuit based on this synchronization signal to synchronize with the carrier signal of the master hydrogen-generating power module, effectively suppressing the generation of zero-sequence circulating current during parallel operation. If the synchronization clock signal is not received, the slave hydrogen-generating power module will also trigger a "carrier abnormality alarm," prompting the user to check the master-slave communication link and related control parameter configuration.

[0039] The carrier synchronization process described above ensures that the carrier signals of all parallel hydrogen production power modules maintain consistency in frequency and phase, effectively suppressing high-frequency circulating currents caused by carrier asynchrony. If a signal anomaly is detected at any point during the synchronization process, the system will output a carrier anomaly alarm, prompting the user to inspect and address the carrier synchronization link.

[0040] In step S101, the configured current loop controller collects the AC current signal from each hydrogen production power module in real time. The collected AC current signal undergoes a transformation from a three-phase stationary coordinate system to a rotating coordinate system (i.e., the abc to dq0 coordinate system) to extract the output current components. This coordinate transformation helps convert the three-phase asymmetric AC signal into two static components and one zero-sequence component, thereby simplifying the control process and improving current control accuracy.

[0041] Combine Figure 3 As shown, in one embodiment, step S101 includes:

[0042] Using a preset current loop controller to collect the three-phase AC current signal of the hydrogen production power module;

[0043] Transforming the three-phase AC current signal from a three-phase stationary coordinate system to a rotating coordinate system, and extracting a direct-axis current component, a quadrature-axis current component, and a zero-sequence current component;

[0044] The preset reference values of the direct-axis current component, the quadrature-axis current component and the zero-sequence current component are all set to zero to establish a current closed-loop control.

[0045] In this embodiment, during the operation of the system, the current loop controller configured in each hydrogen production power module is first used to collect the three-phase AC output current signal. The current loop controller inputs the real-time collected three-phase current signal into the coordinate transformation module, and converts the three-phase AC current signal into the direct axis current component I through ABC / dq0 transformation (i.e., transformation from the three-phase stationary coordinate system to the rotating coordinate system). d , quadrature-axis current component I q And the zero-sequence current component I0. This transformation process is based on the Park transformation principle, which converts the changing three-phase AC signal in the time domain into a stable DC signal form, which is beneficial to subsequent control and regulation.

[0046] In order to construct an effective current closed-loop control system, the reference values of the three current components are set to zero as the target control values. That is: I d _ref=0,I q _ref=0,I0_ref=0,the goal is to achieve zero sequence current and positive sequence component (I d , I q ) minimum deviation, thereby ensuring the consistency of the output current amplitude and phase of the parallel modules, and minimizing the circulation effect caused by current inconsistency.

[0047] Figure 3 Two parallel hydrogen production power modules are demonstrated, namely the master hydrogen production power module and the slave hydrogen production power module. Each module includes components such as current sampling, coordinate transformation, current controller, SVPWM modulator and power converter, which are used to achieve precise regulation and closed-loop control of active, reactive and zero-sequence currents in the parallel system.

[0048] In the main hydrogen machine power supply module ( Figure 3 Upper part), three-phase AC power signal (e a 、e b 、e c) is first input into the phase-locked loop (PLL) module to obtain the system synchronization angle information θ. This angle information is used for the subsequent abc-dq coordinate transformation to convert the three-phase signal into the direct axis current component I d1 and the quadrature-axis current component I q1 I d1 and I q1 Respectively with the reference value I d1 _ref and I q1 _ref is compared to form a current error signal, which is then input to the controller for PI adjustment. The adjusted control signal U d1 and U q1 After the inverse transformation from dq to αβ coordinates, we get U α1 and U β1 And input to the space vector pulse width modulator (SVPWM) to generate a three-phase control signal to drive the power converter output in the main hydrogen power module.

[0049] In the slave hydrogen power module ( Figure 3 The lower half of the module also receives the three-phase input current signal and extracts the synchronization angle information through the phase-locked loop. The difference is that this module uses the abc-dq0 coordinate transformation method to extract the I d2 and I q2 In addition to the two positive sequence current components, the zero sequence current component I0 is also extracted to detect and control the zero sequence circulating current. The three components are respectively compared with the corresponding reference values I d2 _ref, I q2 _ref and I0_ref are compared and the error signals are obtained and input into three parallel current controllers for adjustment. d2 、U q2 After integrating with U0, the inverse transformation of dq0-αβ coordinates is completed to obtain U α2 and U β2 , and input to the SVPWM module to realize power modulation and output control of the slave module.

[0050] Throughout the system, the master module primarily implements rapid regulation of positive-sequence current, while the slave module is responsible for detecting and suppressing zero-sequence current. This master-slave coordination and multi-axis control strategy effectively improves the current-sharing capability of the parallel system, significantly suppresses high-frequency and zero-sequence circulating currents, reduces component stress, and improves system stability and reliability.

[0051] In step S102 , the obtained output current component is compared with a preset reference value to obtain a current deviation value, which will be used as an input parameter of a subsequent control algorithm.

[0052] In one embodiment, step S102 includes:

[0053] In some of the hydrogen production power supply modules, the direct-axis current component and the quadrature-axis current component are controlled to reduce a computational load;

[0054] In another part of the hydrogen production power supply module, the direct-axis current component, the quadrature-axis current component and the zero-sequence current component are controlled to suppress the zero-sequence circulating current.

[0055] In this embodiment, in order to achieve high efficiency of current regulation and effective suppression of zero-sequence circulating current in the system, differentiated current control strategies are adopted for different hydrogen production power modules. The purpose is to optimize the allocation of controller computing resources and improve the overall response speed and stability of the system while ensuring control performance. In the application of specific control strategies, some hydrogen production power modules adopt a control strategy based on the dq coordinate system, and only the direct axis (I d ) and the cross axis (I q ) current component. This strategy simplifies the control model and ignores the regulation of the zero-sequence component, thereby reducing the controller's computational load and real-time processing pressure. It is suitable for modules with limited resources or less impact on the circulation in the system. For the other part of the hydrogen power supply module with relatively abundant computing resources, a more comprehensive dq0 control strategy is adopted. Under this strategy, the controller not only regulates the positive sequence component (I d , I q ) performs conventional control and also monitors and adjusts the zero-sequence current component (I0) in real time. This control method effectively suppresses zero-sequence circulating currents caused by parallel operation of multiple modules, improving the current sharing capability and dynamic stability of the parallel system. The combination of these two strategies achieves more efficient current sharing control and circulating current suppression.

[0056] In step S103, the current deviation value is controlled and processed based on the PI regulation algorithm. The deviation values of the direct axis, quadrature axis, and zero axis can be adjusted separately to generate corresponding output control signals. These output control signals include at least a zero-sequence control signal and may also include a direct-axis control signal and a quadrature-axis control signal. The direct-axis control signal, the quadrature-axis control signal, and the zero-sequence control signal correspond to active power control, reactive power control, and zero-sequence circulating current suppression, respectively. PI regulation dynamically adjusts the control output based on the deviation trend, achieving real-time closed-loop control of the current components and improving the system's dynamic response and stability.

[0057] Combine Figure 4 As shown, in one embodiment, step S103 includes:

[0058] A parallel equivalent model for adjusting the output control signal is established according to the following formula:

[0059]

[0060] Among them, i an 、i bn 、i cn Indicates the zero-sequence circulating current of each phase; Indicates the rate of change of each phase current; L n Represents equivalent inductance; R n Represents equivalent resistance; v anN 、v bnN 、v cnN Indicates the voltage difference between the output terminal voltage of each phase and the voltage of the parallel point N; e a 、e b 、e c Indicates the driving voltage of each phase; v NO Indicates the common neutral point voltage.

[0061] In this embodiment, Figure 4 The output side equivalent voltage source, series resistance and series inductance of two hydrogen production power modules are shown. Specifically, the output equivalent voltage of the first hydrogen production power module is expressed as dm1V dc1 / 2, the output equivalent voltage of the second hydrogen production power module is expressed as dm2V dc2 / 2), where dm1 and dm2 represent the PWM duty cycles of the two modules in their current working states, V dc1 、V dc2 The outputs of the two modules are connected via an equivalent circuit. The circuit of the first module includes a series resistor R1 and an inductor L1, and the circuit of the second module includes a series resistor R2 and an inductor L2.

[0062] Since there may be a slight deviation in the duty cycles dm1 and dm2 of the two modules in actual operation, which leads to a difference in output voltage, the difference forms a driving voltage in the closed loop, thereby stimulating a part of the return current i m This current circulates between the two modules, forming an intermediate-frequency circulating current. The magnitude of this intermediate-frequency circulating current is related to the duty cycle deviation, voltage difference, total loop inductance L1+L2, and resistance R1+R2. Its dynamic characteristics can be used to build simulation models or as an equivalent control object in controller design. It is particularly suitable for parameter tuning of current sharing controllers, voltage regulators, and harmonic suppression modules in parallel systems.

[0063] If the high-level duty cycles used to regulate the zero-sequence component in two parallel hydrogen-generating power modules differ within the same PWM carrier cycle, a voltage difference will be generated along the zero-axis (0-axis) in the dq0 coordinate system. This voltage difference acts on the loop inductance of the two power supplies, forming a closed-loop zero-sequence circulating current within them. Since this zero-sequence circulating current flows only within each module and does not pass through the system load, its amplitude is independent of the system load. A clockwise zero-sequence circulating current is defined as the positive direction. To accurately describe the generation and propagation characteristics of this zero-sequence circulating current, a decoupled model of the three-phase AC current is performed using the dq0 coordinate transformation, decomposing it into three components: the direct axis (d-axis), the quadrature axis (q-axis), and the zero axis (0-axis). The zero-sequence circulating current primarily manifests as the zero-sequence current component, whose dynamic characteristics are governed by multiple system parameters, including the DC bus voltage, the output bus voltage, the zero-sequence duty cycle difference, and the loop filter inductance.

[0064] Based on this, a parallel equivalent dynamic equation system (i.e., a parallel equivalent model) was established to describe the relationship between the zero-sequence circulating current in each phase and its variations under the drive of equivalent inductance, resistance, and voltage. This parallel equivalent dynamic equation system reflects the response behavior of the circulating current at different phases. By incorporating this model into the control strategy design, effective modeling of current deviation can be achieved.

[0065] In step S104, the SVPWM algorithm can be used to integrate and process the output control signals to generate the final control signal. SVPWM technology calculates the on-off time and switching sequence of the power module's switching devices based on the vector instructions of the output control signal, generating a PWM waveform for driving the power transistors. This control signal is used to drive the power switching devices in the hydrogen production power module, effectively regulating the power output. In particular, this control signal plays a key role in suppressing zero-sequence current circulation, ensuring current balance and system stability during parallel operation of multiple modules.

[0066] Combine Figure 5 As shown, in one embodiment, step S104 includes:

[0067] Inputting the zero-sequence control signal into a second-order low-pass filter to filter out high-frequency noise to obtain an effective filtered signal;

[0068] The effective filtered signal is amplitude-adjusted by a gain module to obtain an amplified control signal;

[0069] The amplified control signal is input into a feedback regulation path to achieve dynamic closed-loop control of the zero-sequence current.

[0070] In this embodiment, the dynamic response characteristics of the entire system are first modeled and analyzed based on Laplace transform theory. Through characteristic response analysis in the transform domain, the system's stability margin and response speed in the face of disturbances are determined. Subsequently, the system configures matching filter parameters based on the natural resonant frequencies of the converter and filter circuits, aligning its filtering characteristics with the system's frequency response curve, thereby enhancing its ability to suppress high-frequency interference.

[0071] During the signal acquisition phase, the AC input current is monitored in real time using a current sensor. A proportional controller is then used to convert the acquired three-phase current signals into corresponding zero-sequence current signals, which serve as the input for subsequent regulation and control. The zero-sequence control signal is first fed into a second-order low-pass filter to remove high-frequency noise. This filter is designed with a cutoff frequency that matches the characteristics of the zero-sequence current control channel, ensuring interference removal without compromising control signal response speed.

[0072] Furthermore, the effective filtered signal after filtering is input into the gain module to perform amplitude regulation. This process adjusts the gain of the control signal to ensure that the signal amplitude reaches the control level required to drive the power module, improving the responsiveness and execution of the control effect. The amplified control signal is introduced into the feedback regulation path to establish a complete dynamic closed-loop control chain. This feedback loop compares the error between the control target value and the current actual value in real time, and through continuous adjustment, further optimizes the system's dynamic performance and achieves stable control of the zero-sequence current.

[0073] Figure 5 From left to right, they are the error operation module, the composite controller module, the first-order low-pass filter module, the zero-sequence current channel modeling module, and the feedback loop module, forming a negative feedback control process for the zero-sequence current I z Closed-loop regulation control is performed to suppress the zero-sequence circulating current in the parallel hydrogen power system. The specific control part is described as follows:

[0074] The error calculation module compares the target reference value of the zero-sequence current (generally set to 0) with the actual zero-sequence current currently detected to generate a current deviation value as the input of the closed-loop control.

[0075] The transfer function of the composite controller module consists of two parts: a proportional gain term K p , used for fast linear response to errors; another second-order resonant control unit It is used to dynamically filter and compensate the zero-sequence current in a specific frequency range (such as near the switching frequency); finally, the composite controller module outputs the adjusted control signal.

[0076] A first-order low-pass filter with a transfer function of It is used to filter out high-frequency noise and prevent error amplification, and further smooth the control signal of the composite controller to improve system stability.

[0077] The zero-sequence current channel modeling module simulates the dynamic behavior of the current transmission path in the actual parallel power supply system. The transfer function is:

[0078]

[0079] Among them, (L1, L2) represents the equivalent inductance within the system; (R1, R2) represents the impedance element within the system; further characterizes the response dynamics of the inductor-resistor series network to the control signal, and finally outputs the adjusted zero-sequence current I z , for feedback.

[0080] Feedback loop, the output zero-sequence current is fed back to the error calculation node to form a closed-loop control, realize dynamic real-time suppression of zero-sequence current, and enhance the parallel stability of the system.

[0081] Combine Figure 6 As shown, an embodiment of the present invention also provides a hydrogen production power supply parallel control system adopting the hydrogen production power supply parallel control method as described above, including: a host computer 1, a parallel controller 2 and multiple hydrogen production power supply modules 6, the hydrogen production power supply module 6 includes a digital signal controller 3, a power control unit 4 and a power module 5 connected in sequence; the host computer 1 is communicatively connected to the parallel controller 2; the parallel controller 2 is communicatively connected to each digital signal controller 3 respectively; the parallel controller 2 is used to process user interaction, communication protocol conversion and parallel power distribution.

[0082] In this embodiment, the host computer 1 and the parallel controller 2 communicate via an Ethernet interface. The host computer primarily implements functions such as the human-machine interface, operating status monitoring, parameter configuration, and fault diagnosis. The parallel controller 2, as the system's coordination and control unit, is responsible for processing user interaction commands, performing communication protocol conversion, and dynamically allocating and scheduling parallel power based on real-time operating status. The parallel controller 2 is capable of controlling the coordinated operation of multiple hydrogen-generating power modules 6 and is a key component for the system's stable parallel operation.

[0083] In terms of communication structure, the parallel controller 2 communicates with multiple digital signal controllers 3 simultaneously via optical fiber links and the 485 bus, achieving high-speed data transmission and multi-level information exchange. The 485 communication link is primarily responsible for uploading and downloading equipment status information, alarm information, and configuration parameters; the optical fiber communication link is used for real-time transmission of key control signals, including master-slave control instructions, carrier synchronization signals, and current sharing control instructions, to ensure the consistency of control logic and synchronization of responses between parallel modules. Each hydrogen production power supply module 6 is sequentially configured with three parts: a digital signal controller 3, a power control unit 4, and a power module 5. The digital signal controller 3 is responsible for the protection function, logic startup control, and core control logic operations of the hydrogen production power supply; the power control unit 4 is used to generate a drive signal to control the working state of the power module 5.

[0084] Combine Figure 7 As shown, in one embodiment, the digital signal controller 3 includes a first sub-board 7 for realizing protection control and logic startup of the hydrogen production power supply and a first motherboard 8 for performing device status detection, internal IO sampling and external communication. The first sub-board 7 and the first motherboard 8 are connected by a cable.

[0085] In this embodiment, the digital signal controller 3 in the hydrogen power supply parallel control system utilizes a hierarchical motherboard / daughterboard design to enhance the control system's modularity and maintainability. The first daughterboard 7 and the first motherboard 8, respectively, handle core control and peripheral interface functions. A 60-pin cable allows for high-speed signal transmission and power supply connectivity between the first daughterboard 7 and the first motherboard 8. The first daughterboard 7, serving as the core control unit of the digital signal controller 3, integrates a main control chip and key control logic circuits. It is dedicated to implementing functions such as hydrogen power supply protection control, startup logic, power control command generation, and internal system data processing and scheduling. The first daughterboard 7 boasts high real-time and high-precision signal processing capabilities and serves as the decision-making core of the entire control system. The first motherboard 8, acting as an interface board, is primarily responsible for detecting external device status, collecting internal I / O signals, and communicating with the system's external environment. The first motherboard 8 integrates a sampling module, communication ports, and an I / O processing unit for interfacing with field devices. It uploads collected switching and analog signals to the first daughterboard 7 for processing. It also receives control commands output by the first daughterboard 7 and forwards them to the power control unit 4 or the host computer 1. Through the collaborative design of the motherboard and daughterboard structure, the Digital Signal Controller 3 not only achieves a clear division of functional modules, facilitating subsequent system maintenance and module replacement, but also improves the scalability and adaptability of the control system. Furthermore, the 60-pin cable connection solution ensures high-speed and stable transmission of control signals between the two boards, reducing wiring complexity and the risk of signal interference, and improving the reliability and anti-interference capabilities of the entire system.

[0086] like Figure 7 As shown, the first daughter board 7 and the first motherboard 8 transmit signals and data through the P02 connector. The first daughter board 7 integrates a digital signal processor (DSP) and a field programmable gate array (FPGA) chip, which is used to perform protection control, logical judgment, modulation calculation and other functions of the hydrogen production power module. The first daughter board 7 establishes a high-speed communication channel with the first motherboard 8 through the P02 interface, and interacts with the external drive system through multiple pin interfaces provided on the first daughter board 7 to realize multi-channel input and output management. The first motherboard 8 serves as an interface board, mainly used for signal acquisition, conversion and external communication control, and specifically includes the following interfaces and functional modules:

[0087] DC voltage 24V: supplies power to the entire digital signal controller;

[0088] Status detection: used to detect the system working status and the operating status of the peripheral power module;

[0089] A0 signal: used to collect external analog input signals;

[0090] Drive control: used to output PWM and other control signals to the power unit;

[0091] Start and stop control: used to receive or issue start, stop and other control instructions;

[0092] 485 communication: used for serial communication with the host computer or other controllers;

[0093] AI signal: acquisition channel for analog input signals;

[0094] CAN communication: used to communicate and interact with the system CAN bus network.

[0095] In one embodiment, the power control unit includes a second daughter board for driving and controlling the power module and a second mother board for sampling the output current and voltage, and the second daughter board is connected to the second mother board via pins.

[0096] In this embodiment, the power control unit 4 in the hydrogen power parallel control system can also adopt a mother-daughter board structure design to achieve real-time sampling and monitoring of the drive and output parameters of the power module 5. The power control unit 4 includes a second daughter board and a second mother board (the structure is the same as the first daughter board 7 and the first mother board 8, which can be referred to in detail). Figure 7), the second daughterboard and the second motherboard are connected via a 52-pin connector to ensure stable transmission of high-speed and power signals. The second daughterboard serves as an interface control board, whose primary function is to generate and output PWM drive signals based on control instructions from the digital signal controller 3 to control the on and off of power devices (such as IGBTs or MOSFETs) in the power module 5. The control signals received by the second daughterboard include direct-axis, quadrature-axis, and zero-sequence current control components. After processing using the space vector pulse width modulation (SVPWM) algorithm, it outputs precise gate drive waveforms, thereby achieving effective control and stable drive of the power module. The second motherboard serves as a sampling board, integrating current and voltage sampling circuits and an analog-to-digital conversion interface, specifically for real-time acquisition of key electrical parameters at the output of the power module 5, such as output current and voltage. The collected analog signals are filtered and amplified before being transmitted to the digital signal controller 3 for control algorithm calculations, enabling feedback regulation of the system status. This structure effectively ensures stable operation and control accuracy of the system.

[0097] To ensure high-speed transmission of control commands and coordinated operation between parallel modules, a communication connection is established between the digital signal controller 3 and the power control unit 4 via an optical fiber link. This optical fiber connection not only enables low-latency, high-bandwidth data exchange, but also has strong resistance to electromagnetic interference, making it particularly suitable for power control systems in high-frequency switching scenarios. In addition, this system also includes two types of links: 485 communication and optical fiber communication. 485 communication is primarily used to upload general data such as device operating status, parameter configuration, and fault information, serving as a regular interaction channel between the host computer 1 and the parallel controller 2. The optical fiber communication link, on the other hand, undertakes key real-time control tasks such as master-slave control, current sharing scheduling, and carrier synchronization, ensuring the coordinated and consistent operation of the parallel system modules and avoiding system oscillation or circulating current caused by control delays or signal loss of synchronization.

[0098] Combine Figure 8 As shown, in one embodiment, the circuit topology of the hydrogen production power supply module includes an AC / DC converter and a DC / DC converter, the input end of the AC / DC converter is connected to the positive and negative bus bars on the DC side; the input end of the DC / DC converter is connected to the output end of the AC / DC converter, and the output end of the DC / DC converter is connected to the positive and negative bus bars on the output side.

[0099] In this embodiment, if Figure 8 As shown, two groups of hydrogen production power modules are set up, and each group of modules is connected to the three-phase AC power supply terminal (e a 、e b 、e c) are connected and connected in parallel to the same load Z, which is used to realize a hydrogen production system with dual hydrogen production power supply modules connected in parallel. The circuit topology of the hydrogen production power supply module adopts a hierarchical conversion structure, including two-stage power conversion units of AC / DC converter and DC / DC converter, which are used to realize efficient conversion of AC power to DC power and stable power supply to meet the electrolyzer's requirements for stable DC voltage and current. Specifically, the AC / DC converter serves as a primary conversion unit, and its input receives the AC voltage signal from the three-phase power grid, and its output is connected to the DC side positive and negative bus of the system. The AC / DC converter adopts a power factor correction (PFC) topology to realize the shaping of the input current waveform, improve the power factor of the system and reduce the input current harmonics. Filter inductors and parasitic resistors are provided in its circuit to suppress high-frequency disturbances and improve the rectification quality, thereby ensuring that the output end obtains a stable, low-ripple DC voltage. The DC / DC converter serves as a secondary conversion unit, and its input is connected to the output of the AC / DC converter for further stepping down and shunting the DC voltage. The DC / DC converter utilizes a multi-channel Buck converter structure, consisting of two or more parallel switching tube bridge arms. These bridge arms work together to achieve current balancing, thermal load balancing, and modular scalability. Filter inductors and parasitic resistors are also included in the DC / DC circuit to smooth the output current and improve power quality at the load. Its output terminals are connected to the positive and negative output busbars, providing stable power to load equipment such as electrolyzers. Regarding the system startup sequence, to avoid high current surges and abnormal power module responses, a phased startup strategy is adopted: first, the AC / DC converter is started to establish the DC bus voltage; then, the DC / DC converter is started to achieve steady-state power supply to the load. This sequence helps improve startup stability and extend the life of the power components.

[0100] The present invention combines zero-sequence current control with carrier synchronization control technology to suppress zero-sequence circulating current and high-frequency circulating current generated by module differences in the parallel system, reducing energy loss and heat accumulation. The reduction in circulating current effectively reduces system voltage and current fluctuations, reduces the thermal and electrical stresses of components, and thus extends the service life of the devices in the hydrogen production power module. In addition, the controller adopts a mother-daughter board structure design, which has good modularity and scalability. During actual maintenance, the faulty daughter board can be quickly located and replaced, simplifying the maintenance process, reducing upgrade and operation and maintenance costs, and improving the utilization efficiency of system resources.

[0101] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of this application, several improvements and modifications can be made to this application, and these improvements and modifications also fall within the scope of protection of the claims of this application.

[0102] It should also be noted that, in this specification, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

Claims

1. A method for controlling a hydrogen production power supply in parallel, for controlling a plurality of hydrogen production power supply modules in parallel, characterized in that: include: collecting the AC current signal of each of the hydrogen production power modules, and transforming the AC current signal from a three-phase stationary coordinate system to a rotating coordinate system to obtain an output current component; Comparing the output current component with a preset reference value to obtain a current deviation value; The current deviation value is controlled based on a proportional-integral (PI) regulation algorithm to obtain an output control signal; wherein the output control signal at least includes a zero-sequence control signal; The output control signals are integrated based on a space vector pulse width modulation (SVPWM) algorithm to generate a control signal, wherein the control signal is used to achieve electric energy output to suppress zero-sequence circulating current.

2. The method for controlling the parallel operation of hydrogen production power supplies according to claim 1, characterized in that: The method for controlling parallel operation of hydrogen production power supplies further includes: When the hydrogen production power supply parallel system is started, it is determined whether the current hydrogen production power supply module is a master hydrogen production power supply module or a slave hydrogen production power supply module; When it is determined that the master hydrogen-making power supply module is the master, it is determined whether a pulse width modulation (PWM) synchronous clock signal is received, and whether the PWM synchronous clock signal is consistent with the preset master signal. If they are consistent, the PWM synchronous clock signal is output, and the PWM synchronous clock signal is converted into an electrical signal and sent to the carrier control circuit of the slave hydrogen-making power supply module. If the PWM synchronous clock signal is not received or the PWM synchronous clock signal is inconsistent with the preset master signal, a carrier abnormality alarm is output; When it is determined to be a slave hydrogen-making power supply module, it is determined whether the PWM synchronous clock signal sent by the master hydrogen-making power supply module is received. If the PWM synchronous clock signal is not received, a carrier abnormality alarm is output; if the PWM synchronous clock signal is received, the zero-sequence circulating current is suppressed according to the PWM synchronous clock signal.

3. The method for controlling the parallel operation of hydrogen production power supplies according to claim 1, characterized in that: The step of integrating the output control signals based on the space vector pulse width modulation algorithm and generating a control signal includes: Inputting the zero-sequence control signal into a second-order low-pass filter to filter out high-frequency noise to obtain an effective filtered signal; The effective filtered signal is amplitude-adjusted by a gain module to obtain an amplified control signal; The amplified control signal is input into a feedback regulation path to achieve dynamic closed-loop control of the zero-sequence current.

4. The method for controlling the parallel operation of hydrogen production power supplies according to claim 1, characterized in that: The collecting of the AC current signal of each of the hydrogen production power modules, and performing a transformation from a three-phase stationary coordinate system to a rotating coordinate system on the AC current signal to obtain an output current component includes: Using a preset current loop controller to collect the three-phase AC current signal of the hydrogen production power module; Transforming the three-phase AC current signal from a three-phase stationary coordinate system to a rotating coordinate system, and extracting a direct-axis current component, a quadrature-axis current component, and a zero-sequence current component; The preset reference values of the direct-axis current component, the quadrature-axis current component and the zero-sequence current component are all set to zero to establish a current closed-loop control.

5. The method for controlling the parallel operation of hydrogen production power supplies according to claim 4, characterized in that: The comparing the output current component with a preset reference value to obtain a current deviation value includes: In some of the hydrogen production power supply modules, the direct-axis current component and the quadrature-axis current component are controlled to reduce a computational load; In another part of the hydrogen production power supply module, the direct-axis current component, the quadrature-axis current component and the zero-sequence current component are controlled to suppress the zero-sequence circulating current.

6. The method for controlling the parallel operation of hydrogen production power supplies according to claim 1, characterized in that: The current deviation value is controlled based on the PI adjustment algorithm to obtain an output control signal, including: A parallel equivalent model for adjusting the output control signal is established according to the following formula: Among them, i an 、i bn 、i cn Indicates the zero-sequence circulating current of each phase; Indicates the rate of change of each phase current; L n Represents equivalent inductance; R n Represents equivalent resistance; v anN 、v bnN 、v cnN Indicates the voltage difference between the output terminal voltage of each phase and the voltage of the parallel point N; e a 、e b 、e c Indicates the driving voltage of each phase; v NO Indicates the common neutral point voltage.

7. A hydrogen production power supply parallel control system using the hydrogen production power supply parallel control method according to any one of claims 1 to 6, characterized in that: include: A host computer, a parallel controller and multiple hydrogen production power modules, wherein the hydrogen production power module includes a digital signal controller, a power control unit and a power module connected in sequence; the host computer is communicatively connected to the parallel controller; the parallel controller is communicatively connected to each of the digital signal controllers respectively; the parallel controller is used to handle user interaction, communication protocol conversion and parallel power distribution.

8. The hydrogen production power supply parallel control system according to claim 7, characterized in that: The digital signal controller includes a first daughter board for implementing protection control and logic startup of the hydrogen production power supply and a first mother board for performing device status detection, internal IO sampling and external communication. The first daughter board and the first mother board are connected via a cable.

9. The hydrogen production power supply parallel control system according to claim 7, characterized in that: The power control unit includes a second daughter board for driving and controlling the power module and a second mother board for sampling output current and voltage. The second daughter board is connected to the second mother board via pins.

10. The hydrogen production power supply parallel control system according to claim 7, characterized in that: The circuit topology of the hydrogen production power supply module includes an AC / DC converter and a DC / DC converter, wherein the input end of the AC / DC converter is connected to the positive and negative busbars on the DC side; the input end of the DC / DC converter is connected to the output end of the AC / DC converter, and the output end of the DC / DC converter is connected to the positive and negative busbars on the output side.

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