Hydrogen production power supply system matched with new energy fluctuating power grid and control method of hydrogen production power supply system

Abstract

The invention provides a hydrogen production power supply system matched with a new energy fluctuation power grid and a control method of the hydrogen production power supply system. The hydrogen production power supply system comprises a wind-solar power generation unit, an energy storage unit, a hydrogen production power supply unit, a load unit and an alternating current bus, the alternating current bus is respectively connected with the wind-solar power generation unit, the energy storage unit and the hydrogen production power supply unit; the wind-solar power generation unit is used for transmitting electric energy to the alternating current bus; the energy storage unit is used for acquiring electric energy from the alternating current bus, storing the electric energy or transmitting the electric energy to the alternating current bus; the hydrogen production power supply unit is used for converting alternating current of the alternating current bus into direct current and transmitting electric energy to the load unit; and the load unit is used for obtaining electric energy from the hydrogen production power supply unit, electrolyzing water to produce hydrogen by using the obtained electric energy, improving the new energy consumption capability of the wind-solar power generation off-grid hydrogen production system and maintaining stable operation of the new energy power generation and hydrogen production system.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrogen production by electrolysis of water, and in particular relates to a hydrogen production power supply system matching a new energy fluctuating power grid and a control method thereof. Background Art

[0002] In order to solve the energy crisis and environmental pollution problems, new energy power generation based on renewable clean energy such as solar energy and wind energy has received widespread attention. Hydrogen energy, as an important carrier of energy transformation and development, has the characteristics of high energy density, large capacity, long life, easy storage and transmission. The production of hydrogen through electrolysis of water through new energy power generation can not only achieve the complementary conversion of electricity and gas, but also can be directly and efficiently utilized.

[0003] However, green energy such as photovoltaic / wind power has strong volatility, and there is a great deal of uncertainty in the amount of power generated. The power supply in the wind and solar power generation hydrogen production system is all new energy power, and there is a situation where the short-circuit ratio of multiple new energy stations is too low, which will cause the AC system voltage support capacity to be insufficient, the stability is poor, it is extremely sensitive to voltage fluctuations, and the ability to resist system fault disturbances is poor. In addition, the electrolyzer load in the wind and solar power storage hydrogen production system has unique characteristics compared to other ordinary loads, which is manifested as slow dynamic response, and frequent switching will affect the service life of the electrolyzer. When the power generation is large, the hydrogen production power supply system is required to have a higher load operation range to meet the consumption of new energy and the supply of hydrogen production. When the power generation is small, the hydrogen production power supply system is required to have a lower load operation condition to meet the stable operation of the hydrogen production system. Therefore, it is necessary to adopt appropriate control of the hydrogen production power supply to maintain the stable operation of the new energy power generation and hydrogen production system. Therefore, how to improve the new energy consumption capacity of the wind and solar power off-grid hydrogen production system and maintain the stable operation of the new energy power generation and hydrogen production system has become a technical problem that needs to be solved in this field. Summary of the invention

[0004] The object of the present invention is to provide a hydrogen production power supply system and a control method thereof that matches a new energy fluctuating power grid.

[0005] According to a first aspect of the present invention, a hydrogen production power supply system matching a new energy fluctuating power grid is provided, the system comprising: a wind and solar power generation unit, an energy storage unit, a hydrogen production power supply unit, a load unit and an AC bus; the AC bus is respectively connected to the wind and solar power generation unit, the energy storage unit and the hydrogen production power supply unit;

[0006] The wind-solar power generation unit is used to transmit electric energy to the AC bus;

[0007] The energy storage unit is used to obtain electric energy from the AC bus, store electric energy, or transmit electric energy to the AC bus;

[0008] The hydrogen production power supply unit converts the AC power of the AC bus into DC power and transmits electric energy to the load unit. The load unit is used to obtain electric energy from the hydrogen production power supply unit and use the obtained electric energy to electrolyze water to produce hydrogen.

[0009] Optionally, the hydrogen production power supply unit includes at least an AC-to-DC rectifier module and a DC-to-DC voltage regulator module;

[0010] The AC-to-DC rectifier module is used to use a three-phase bridge rectifier circuit to convert the AC power transmitted by the AC bus into DC power, and transmit the DC power to the DC-to-DC voltage regulator module;

[0011] The DC-to-DC voltage regulating module is used to reduce the voltage of the DC power by using an interleaved parallel Buck circuit, and the DC power after voltage reduction is obtained and transmitted to the load unit.

[0012] According to a second aspect of the present invention, a control method for a hydrogen production power supply matching a new energy fluctuating power grid is provided, which is applied to the hydrogen production power supply system matching a new energy fluctuating power grid described in the first aspect.

[0013] Optionally, the method comprises:

[0014] Collecting capacitor voltage data on the output side of an AC-to-DC rectifier module, and voltage data and current data on the input side of the AC-to-DC rectifier module;

[0015] The output side capacitor voltage data, the input side voltage data and the input side current data are processed by a meshing control strategy to obtain a phase angle and an electric potential of the meshing control;

[0016] Obtaining a three-phase reference current based on the phase angle, potential and electromagnetic equation;

[0017] The three-phase reference current is sent to the quasi-PR controller for current closed-loop control to obtain a three-phase modulation wave signal;

[0018] The switching of the switch tube in the three-phase rectifier circuit is controlled based on the three-phase modulation wave signal.

[0019] Optionally, the network control strategy at least includes:

[0020] Bus capacitor voltage regulation part, active power-frequency regulation part, reactive power-voltage regulation part, electromagnetic equation calculation part and quasi-PR current inner loop control part;

[0021] The bus capacitor voltage is regulated by the PI in the bus capacitor voltage regulating part to output an active power reference value. The active-frequency regulating part and the reactive-voltage regulating part enable the hydrogen production power supply to simulate the voltage source characteristics and provide a voltage source for the AC system.

[0022] Optionally, the output side capacitor voltage data, input side voltage data and input side current data are processed by a meshing control strategy to obtain a phase angle and an electric potential of meshing control, including:

[0023] Generate a mechanical torque of the grid-type control according to an initial mechanical torque of the grid-type control and an active power-frequency adjustment signal of the grid-type control;

[0024] The electromagnetic torque of the grid-type control is calculated according to the three-phase potential, the three-phase reference current and the rated angular velocity of the AC side;

[0025] The grid-type control damping torque is calculated according to the angular velocity of the AC side, the rated angular velocity of the AC side and the damping coefficient;

[0026] The angular velocity of the network-type control is obtained according to the mechanical torque, electromagnetic torque and damping torque of the network-type control;

[0027] Calculate the phase angle of the mesh control according to the mechanical angular velocity of the mesh control;

[0028] Calculating the reactive power regulation potential and the voltage regulation potential of the grid-type control according to the phase angle of the grid-type control;

[0029] According to the phase angle and potential of the grid-type control, the three-phase reference current is obtained in combination with the electromagnetic equation.

[0030] Optionally, the quasi-PR controller includes:

[0031] Clark transformation module, used to perform Clark transformation on the three-phase reference current and AC side current data to obtain the three-phase current sampling signal and current reference signal of the grid-type control in the two-phase stationary coordinate system;

[0032] The quasi-PR control module is used to process the three-phase current sampling signal and the current reference signal of the grid-type control to obtain the modulation signal in the αβ coordinate system;

[0033] The Clark inverse transformation module is used to perform Clark inverse transformation on the modulation signal in the αβ coordinate system to obtain a three-phase modulation wave signal.

[0034] Optionally, controlling the switching of a switch in a three-phase rectifier circuit based on the three-phase modulation wave signal includes:

[0035] The three-phase modulated wave signal is sent to the PWM modulator to generate a PWM signal, which is used to control the switching of the rectifier module of the AC to DC converter.

[0036] Optionally, the method further comprises:

[0037] According to the power characteristics of the load, the input side voltage data, the output side voltage data and the current data are processed through double closed-loop control to obtain a modulated wave signal, and the obtained PWM drive signal is interleaved;

[0038] The switching of the switch tubes in the interleaved parallel Buck circuit is controlled according to the PWM driving signal after interleaving processing to realize voltage regulation control.

[0039] Optionally, the method further comprises:

[0040] The output voltage is adjusted by the PI of the output voltage outer loop control part to output the current reference value. The output current is adjusted by the PI of the output current inner loop control part to output the modulation wave signal. The modulation wave signal is generated by the PWM modulator to generate the PWM signal. The PWM signal is interleaved to control the switching of each Buck branch switch.

[0041] The beneficial effects brought by the present invention are as follows:

[0042] It can be seen from the above scheme that an embodiment of the present invention provides a hydrogen production power supply system and control method that matches a new energy fluctuating power grid, including: a wind and solar power generation unit, an energy storage unit, a hydrogen production power supply unit, a load unit and an AC bus; the AC bus is respectively connected to the wind and solar power generation unit, the energy storage unit, and the hydrogen production power supply unit; the wind and solar power generation unit is used to transmit electric energy to the AC bus; the energy storage unit is used to obtain electric energy from the AC bus, store electric energy, or transmit electric energy to the AC bus; the hydrogen production power supply unit converts the AC power of the AC bus into DC power and transmits electric energy to the load unit; the load unit is used to obtain electric energy from the hydrogen production power supply unit, and use the obtained electric energy to electrolyze water to produce hydrogen, so as to improve the new energy absorption capacity of the wind and solar power generation off-grid hydrogen production system and maintain the stable operation of the new energy power generation and hydrogen production system. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a structural block diagram of a hydrogen production power supply system matching a new energy fluctuating power grid provided according to an embodiment;

[0044] Figure 2 is a diagram of the architecture of a hydrogen production power supply unit provided according to an embodiment;

[0045] Figure 3 A grid-type control method for an AC / DC rectifier unit is provided according to an embodiment;

[0046] Figure 4 A DC / DC voltage regulating unit interleaving parallel control method is provided according to an embodiment. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all 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.

[0048] Reference Figure 1 , shows a structural block diagram of a hydrogen production power supply system matching a new energy fluctuating power grid of the present application, the system includes: a wind and solar power generation unit, an energy storage unit, a hydrogen production power supply unit, a load unit and an AC bus; the AC bus is respectively connected to the wind and solar power generation unit, the energy storage unit, and the hydrogen production power supply unit;

[0049] Wind and solar power generation units are used to transmit electric energy to the AC bus;

[0050] An energy storage unit, used to obtain electric energy from an AC bus, store electric energy, or transmit electric energy to the AC bus;

[0051] A hydrogen production power supply unit converts the AC power of the AC bus into DC power and transmits the power to the load unit;

[0052] The load unit is used to obtain electric energy from the hydrogen production power supply unit and utilize the obtained electric energy to electrolyze water to produce hydrogen.

[0053] The present invention provides a wind and solar power generation off-grid hydrogen production system, the architecture diagram of the system is as follows Figure 1 As shown, it includes a wind-solar power generation unit, an energy storage unit, a hydrogen production power unit, a load unit and an AC busbar; the AC busbar is connected to the wind-solar power generation unit, the energy storage unit and the hydrogen production power unit respectively; the specific functions of each unit include the following parts:

[0054] Wind and solar power generation units are used to transmit electric energy to the AC bus;

[0055] The energy storage unit is used to obtain electric energy from the AC bus, store electric energy, or transmit electric energy to the AC bus. When the output power of the wind and solar power generation unit is less than 20% of the load power, the energy storage unit will supplement it to 20% of the load. When the output power of the wind and solar power generation unit is greater than 110% of the load power, the excess power will be stored by the energy storage unit.

[0056] A hydrogen production power supply unit converts the AC power of the AC bus into DC power and transmits the power to the load unit;

[0057] The load unit is used to obtain electric energy from the hydrogen production power supply unit and utilize the obtained electric energy to electrolyze water to produce hydrogen; the load unit has an adjustment range of 20% to 110%.

[0058] The AC bus is used to collect electric energy from the wind and solar power generation units and the energy storage units; and transmit electric energy to the hydrogen production power supply unit.

[0059] Optionally, the hydrogen production power supply unit includes at least an AC-to-DC rectifier module and a DC-to-DC voltage regulator module;

[0060] The AC-to-DC rectifier module is used to convert the AC power transmitted by the AC bus into DC power using a three-phase bridge rectifier circuit, and transmit the DC power to the DC-to-DC voltage regulator module;

[0061] The DC-to-DC voltage regulation module is used to step down the DC power using an interleaved parallel Buck circuit, and the stepped-down DC power is transmitted to the load unit.

[0062] The hydrogen production power unit architecture is as follows Figure 2 As shown, it includes an AC / DC rectifier unit and a DC / DC voltage regulator unit. The AC / DC rectifier unit adopts a three-phase bridge rectifier circuit to convert the AC power transmitted by the AC bus into DC power and transmit it to the DC / DC voltage regulator unit. The DC / DC voltage regulator unit adopts an interleaved parallel Buck circuit to step down the DC power transmitted by the AC / DC rectifier unit and transmit it to the load unit.

[0063] Another embodiment of the present application provides a hydrogen production power supply control method that matches a new energy fluctuating power grid, which is applied to the above-mentioned hydrogen production power supply system.

[0064] Optionally, the method comprises:

[0065] Collecting capacitor voltage data on the output side of the AC-DC rectifier module, and voltage and current data on the input side of the AC-DC rectifier module;

[0066] Through the network control strategy, the output side capacitor voltage data, input side voltage data and input side current data are processed to obtain the phase angle and potential of the network control;

[0067] Obtain three-phase reference current based on phase angle, potential and electromagnetic equation;

[0068] The three-phase reference current is sent to the quasi-PR controller for current closed-loop control to obtain a three-phase modulation wave signal;

[0069] The opening and closing of the switch tube in the three-phase rectifier circuit is controlled based on the three-phase modulation wave signal.

[0070] Specifically, the second embodiment of the present invention relates to a hydrogen production power system control method, providing a hydrogen production power system control method matching a new energy fluctuating power grid, and in particular, for an AC / DC rectifier unit of a hydrogen production power system, providing a grid-type rectifier control method, the specific implementation method is as follows: Figure 3As shown, the following steps are included:

[0071] Collect capacitor voltage data on the output side of the AC / DC rectifier unit, and voltage and current data on the input side of the AC / DC rectifier unit;

[0072] The output side capacitor voltage data, the input side voltage data and the input side current data are processed through a meshing control loop to obtain a phase angle and an electric potential of meshing control;

[0073] Obtaining a three-phase reference current based on the phase angle, potential and electromagnetic equation;

[0074] The three-phase reference current is sent to the quasi-PR controller for current closed-loop control to obtain a three-phase modulation wave signal;

[0075] The switching of the switch tube in the three-phase rectifier circuit is controlled based on the three-phase modulation wave signal.

[0076] Optionally, the networked control strategy includes at least:

[0077] Bus capacitor voltage regulation part, active power-frequency regulation part, reactive power-voltage regulation part, electromagnetic equation calculation part and quasi-PR current inner loop control part;

[0078] The bus capacitor voltage is adjusted by PI in the bus capacitor voltage adjustment part to output the active power reference value. The active-frequency adjustment part and the reactive-voltage adjustment part enable the hydrogen production power supply to simulate the voltage source characteristics and provide a voltage source for the AC system.

[0079] In this embodiment, the AC / DC rectifier unit grid control strategy is as follows: Figure 3 As shown, it includes bus capacitor voltage regulation part, active-frequency regulation part, reactive-voltage regulation part, electromagnetic equation calculation part and quasi-PR current inner loop control part. The bus capacitor voltage is regulated by PI in the bus capacitor voltage regulation part to output the active power reference value. The active-frequency regulation part and reactive-voltage regulation part allow the hydrogen production power source to simulate the voltage source characteristics, so that the power source can have voltage and frequency support capabilities for the AC system.

[0080] Optionally, the output side capacitor voltage data, the input side voltage data and the input side current data are processed by a meshing control strategy to obtain a phase angle and an electric potential of meshing control, including:

[0081] Generate a mechanical torque of the grid-type control according to an initial mechanical torque of the grid-type control and an active power-frequency adjustment signal of the grid-type control;

[0082] The electromagnetic torque of the grid-type control is calculated according to the three-phase potential, the three-phase reference current and the rated angular velocity of the AC side;

[0083] The grid-type control damping torque is calculated according to the angular velocity of the AC side, the rated angular velocity of the AC side and the damping coefficient;

[0084] The angular velocity of the network-type control is obtained according to the mechanical torque, electromagnetic torque and damping torque of the network-type control;

[0085] Calculate the phase angle of the mesh control according to the mechanical angular velocity of the mesh control;

[0086] According to the phase angle of the grid-type control, the reactive power regulation potential and the voltage regulation potential of the grid-type control are calculated;

[0087] According to the phase angle and potential of the grid-type control, the three-phase reference current is obtained in combination with the electromagnetic equation.

[0088] Specifically, the bus capacitor voltage data, AC side voltage, and current data are processed through a meshing control loop to obtain a meshing control phase angle, which specifically includes the following steps:

[0089] In this embodiment, the mechanical torque of the network control is expressed by T m =T0+ΔT, where T0 is the initial mechanical torque of the grid-forming control, and ΔT is the active power-frequency adjustment signal of the grid-forming control.

[0090] The initial mechanical torque T0 is calculated according to the bus capacitor voltage and the AC side angular velocity. The specific calculation method is: Among them U dcref is the bus capacitor reference voltage of the AC / DC rectifier unit, U dc is the busbar capacitor voltage data, k p and k i are the proportional adjustment coefficient and integral adjustment coefficient of the PI controller of the DC capacitor voltage regulation part in the network control loop, s is the Laplace operator, and ω is the angular velocity on the AC side.

[0091] In this embodiment, the specific calculation method of the active power-frequency adjustment signal ΔT is: T0 = (f0-f)*k f , where f0 is the rated frequency of the AC side, f is the actual frequency of the AC side, k f is the frequency coefficient.

[0092] The specific calculation method of the electromagnetic torque of the network-type control in this implementation is: Among them, T e is the electromagnetic torque of network control, e abc is the three-phase potential, i refabc is the three-phase reference current, ω n is the rated angular velocity on the AC side.

[0093] In this embodiment, the network-type control damping torque T d The specific calculation method is: T d =D(ω-ω n ), where ω is the angular velocity of the AC side, ω n is the rated angular velocity on the AC side, and D is the damping coefficient.

[0094] According to the mechanical torque, electromagnetic torque and damping torque of the network control, the angular velocity of the network control is calculated as follows: Where, ω is the mechanical angular velocity of the load virtual synchronous machine, T m is the mechanical torque of the network control, T e is the electromagnetic torque of network control, J is the moment of inertia; s is the Laplace operator.

[0095] The phase angle of the meshing control is calculated according to the mechanical angular velocity of the meshing control, and the calculation method is: θ=∫ωdt, wherein θ is the phase angle of the meshing control, and dt is the differential unit of time.

[0096] In this embodiment, the potential is Calculated, ΔE Q Represents the reactive power regulation potential of grid-type control; ΔE U represents the voltage regulation potential of the grid-type control; k q is the reactive power regulation coefficient; s is the Laplace operator.

[0097] In this embodiment, the reactive power regulation potential of the grid-type control is determined by △E Q =Q ref -Q is calculated, where Q ref is the reactive power command on the AC side; Q is the instantaneous reactive power on the AC side.

[0098] In this embodiment, the voltage regulation potential of the grid-type control is determined by △E U =k v (U ref -U) is calculated, where k v is the voltage regulation coefficient; U ref is the reference value of the effective value of the AC side line voltage; U is the actual value of the effective value of the AC side line voltage.

[0099] After the above processing of the DC side capacitor voltage data, AC side voltage and current data, the phase angle and potential of the grid-type control can be obtained. Combined with the electromagnetic equation, the three-phase reference current can be obtained. The calculation method is as follows: where i aref 、i bref 、i cref is the three-phase reference current, e a 、e b、e c is the three-phase potential, u a 、u b 、u c is the three-phase voltage; L is the filter inductance on the AC side; R is the parasitic resistance of the filter on the AC side.

[0100] In this embodiment, the three-phase potential of the grid-type control is given by Calculated, where E P is the virtual potential of the network-type control; θ is the phase angle of the network-type control;

[0101] Optionally, the quasi-PR controller comprises:

[0102] Clark transformation module, used to perform Clark transformation on the three-phase reference current and AC side current data to obtain the three-phase current sampling signal and current reference signal of the grid-type control in the two-phase stationary coordinate system;

[0103] The quasi-PR control module is used to process the three-phase current sampling signal and the current reference signal of the grid-type control to obtain the modulation signal in the αβ coordinate system;

[0104] The Clark inverse transformation module is used to perform Clark inverse transformation on the modulation signal in the αβ coordinate system to obtain a three-phase modulation wave signal.

[0105] The three-phase reference current is sent to the quasi-PR controller for current closed-loop control to obtain a three-phase modulated wave signal. In this embodiment, the quasi-PR controller includes:

[0106] Clark transformation module, used to perform Clark transformation on the three-phase reference current and AC side current data to obtain the three-phase current sampling signal and current reference signal of the grid-type control in the two-phase stationary coordinate system;

[0107] The quasi-PR control module is used to process the three-phase current sampling signal and the current reference signal of the grid-type control to obtain the modulation signal in the αβ coordinate system;

[0108] The Clark inverse transformation module is used to perform Clark inverse transformation on the modulation signal in the αβ coordinate system to obtain a three-phase modulation wave signal.

[0109] The transfer function G of the quasi-PR control module in this embodiment is Quasi-PR (s) is expressed as: Among them, k p1 is the proportional coefficient of PR control, k R is the resonance coefficient, ω c is the cut-off frequency, ω0 is the resonant frequency

[0110] The three-phase modulated wave signal is sent to the PWM modulator to generate a PWM signal, which is used to control the switching of the AC / DC rectifier unit.

[0111] Optionally, controlling the switching of a switch tube in a three-phase rectifier circuit based on a three-phase modulation wave signal includes:

[0112] The three-phase modulated wave signal is sent to the PWM modulator to generate a PWM signal, which is used to control the switching of the rectifier module of the AC to DC converter.

[0113] Optionally, the method further comprises:

[0114] According to the power characteristics of the load, the input side voltage data, the output side voltage data and the current data are processed through double closed-loop control to obtain a modulation wave signal, and the obtained PWM drive signal is interleaved;

[0115] The switching of the switch tubes in the interleaved parallel Buck circuit is controlled according to the PWM driving signal after interleaving processing to realize voltage regulation control.

[0116] Optionally, the method further comprises:

[0117] The output voltage is adjusted by the PI of the output voltage outer loop control part to output the current reference value. The output current is adjusted by the PI of the output current inner loop control part to output the modulation wave signal. The modulation wave signal is generated by the PWM modulator to generate the PWM signal. The PWM signal is interleaved to control the switching of each Buck branch switch.

[0118] For a DC / DC voltage regulating unit of a hydrogen production power system, a staggered parallel dual closed-loop control method is provided, comprising the following steps:

[0119] Collect the voltage data on the input side of the DC / DC voltage regulator unit, and the voltage data and current data on the output side of the DC / DC voltage regulator unit;

[0120] According to the power characteristics of the load, the input side voltage data, the output side voltage data and the current data are processed through double closed-loop control to obtain a modulated wave signal, and the obtained PWM drive signal is interleaved;

[0121] The switching of the switch tubes in the interleaved parallel Buck circuit is controlled according to the interleaved PWM drive signal to realize voltage regulation control;

[0122] In this embodiment, the control strategy of the DC / DC voltage regulator unit is as follows: Figure 4As shown, it includes an output voltage outer loop control part, an output current inner loop control part, and an interleaved parallel control part. The output voltage is adjusted by the PI of the output voltage outer loop control part to output the current reference value, and the output current is adjusted by the PI of the output current inner loop control part to output the modulation wave signal. The modulation wave signal is generated by the PWM modulator to generate the PWM signal, and the PWM signal is interleaved to control the switching of each Buck branch switch tube. The output voltage is regulated.

[0123] In this implementation method, the voltage loop reference signal is determined according to the power-voltage characteristics of the input power and the load;

[0124] The output signal of the voltage loop is calculated as: where u ref is the voltage loop reference voltage, u dc is the input voltage data, k v1 is the voltage loop proportional coefficient, k i1 is the voltage loop integration coefficient;

[0125] The current loop input signal calculation method is: where i ref is the voltage loop output signal, n is the number of branches connected in parallel;

[0126] The carrier modulation signal of the DC / DC voltage regulation unit is composed of Calculated, where i ref is the output reference current, i iref is the reference current signal, k v2 is the current loop proportionality coefficient, k i2 is the current loop integral coefficient, n is the number of branches connected in parallel;

[0127] The PWM drive signal is interleaved so that the PWM drive signal of each Buck branch is delayed separately.

[0128] The PWM signals of each branch obtained after interleaving are used to control the opening and closing of each Buck branch switch tube in the DC / DC voltage regulation unit.

[0129] The purpose of the embodiment of the present application is to provide a hydrogen production power supply system and a control method thereof that matches a new energy fluctuating power grid, so as to improve the new energy consumption capacity of the off-grid hydrogen production system of wind and solar power generation and maintain the stable operation of the new energy power generation and hydrogen production system. In order to solve the above technical problems, the technical solution adopted by the embodiment of the present application is to provide a hydrogen production power supply system and a control method thereof that matches a new energy fluctuating power grid. The existing technology solves the problems of insufficient voltage support capacity of the AC system, poor stability, abnormal sensitivity to voltage fluctuations, and poor ability to resist the impact of system fault disturbances. The embodiment of the present application adopts a grid-type control method to provide voltage and frequency support for the AC system, ensure the stable operation of the system, and improve the new energy consumption capacity; the embodiment of the present application provides a hydrogen production power supply system and control method for matching the new energy fluctuating power grid, the method uses the AC side voltage, current data and bus voltage data to obtain the phase angle and potential of the grid-type control, and then calculates the three-phase reference current through the phase angle and potential of the grid-type control, and sends the three-phase current to the quasi-PR controller for current closed-loop control to obtain the three-phase modulation wave signal of the AC / DC rectifier unit; on the other hand, according to the bus voltage, output side voltage data and current data, double closed-loop staggered parallel control is performed to obtain the staggered control signal of the DC / DC voltage regulating unit. It can achieve stable output voltage and power following the set value under steady-state conditions, and provide voltage and frequency support for the system when the wind and solar power generation units fluctuate, and can also achieve dynamic reactive power compensation while quickly and flexibly controlling the transmitted active power, improving system stability, adapting to renewable energy power generation systems with large fluctuations, and further realizing the consumption of new energy.

[0130] The embodiment of the present application provides voltage and frequency support capabilities for the system when the AC system fluctuates, thereby maintaining stable operation of the system; improves the new energy absorption capacity, and has good engineering applicability.

[0131] The beneficial effects brought by the present invention are as follows:

[0132] It can be seen from the above scheme that an embodiment of the present invention provides a hydrogen production power supply system and control method that matches a new energy fluctuating power grid, including: a wind and solar power generation unit, an energy storage unit, a hydrogen production power supply unit, a load unit and an AC bus; the AC bus is respectively connected to the wind and solar power generation unit, the energy storage unit, and the hydrogen production power supply unit; the wind and solar power generation unit is used to transmit electric energy to the AC bus; the energy storage unit is used to obtain electric energy from the AC bus, store electric energy, or transmit electric energy to the AC bus; the hydrogen production power supply unit converts the AC power of the AC bus into DC power and transmits electric energy to the load unit; the load unit is used to obtain electric energy from the hydrogen production power supply unit, and use the obtained electric energy to electrolyze water to produce hydrogen, so as to improve the new energy absorption capacity of the wind and solar power generation off-grid hydrogen production system and maintain the stable operation of the new energy power generation and hydrogen production system.

[0133] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0134] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, a magnetic disk, or an optical disk), and includes a number of instructions for a terminal (which can be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0135] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

[0136] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed in the present application can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0137] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0138] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0139] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0140] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0141] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard drives, ROM, RAM, magnetic disks, or optical disks.

[0142] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0143] The above are preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A hydrogen production power supply system matching a new energy fluctuating power grid, characterized in that: The system comprises: a wind-solar power generation unit, an energy storage unit, a hydrogen production power supply unit, a load unit and an AC bus; the AC bus is respectively connected to the wind-solar power generation unit, the energy storage unit and the hydrogen production power supply unit; The wind-solar power generation unit is used to transmit electric energy to the AC bus; The energy storage unit is used to obtain electric energy from the AC bus, store electric energy, or transmit electric energy to the AC bus; The hydrogen production power supply unit converts the AC power of the AC bus into DC power and transmits the power to the load unit; The load unit is used to obtain electric energy from the hydrogen production power supply unit, and utilize the obtained electric energy to electrolyze water to produce hydrogen.

2. The hydrogen production power supply system according to claim 1, characterized in that: The hydrogen production power supply unit at least includes an AC-to-DC rectifier module and a DC-to-DC voltage regulator module; The AC-to-DC rectifier module is used to use a three-phase bridge rectifier circuit to convert the AC power transmitted by the AC bus into DC power, and transmit the DC power to the DC-to-DC voltage regulator module; The DC-to-DC voltage regulating module is used to reduce the voltage of the DC power by using an interleaved parallel Buck circuit, and the DC power after voltage reduction is obtained and transmitted to the load unit.

3. A control method for a hydrogen production power source matching a new energy fluctuating power grid, characterized in that: Applicable to the hydrogen production power supply system as described in any one of claims 1-2.

4. The control method according to claim 3, characterized in that: The method comprises: Collecting capacitor voltage data on the output side of an AC-to-DC rectifier module, and voltage data and current data on the input side of the AC-to-DC rectifier module; The output side capacitor voltage data, the input side voltage data and the input side current data are processed by a meshing control strategy to obtain a phase angle and an electric potential of the meshing control; Obtaining a three-phase reference current based on the phase angle, potential and electromagnetic equation; The three-phase reference current is sent to the quasi-PR controller for current closed-loop control to obtain a three-phase modulation wave signal; The switching of the switch tube in the three-phase rectifier circuit is controlled based on the three-phase modulation wave signal.

5. The control method according to claim 4, characterized in that: The network control strategy at least includes: Bus capacitor voltage regulation part, active power-frequency regulation part, reactive power-voltage regulation part, electromagnetic equation calculation part and quasi-PR current inner loop control part; The bus capacitor voltage is regulated by the PI in the bus capacitor voltage regulating part to output an active power reference value. The active-frequency regulating part and the reactive-voltage regulating part enable the hydrogen production power supply to simulate the voltage source characteristics and provide a voltage source for the AC system.

6. The control method according to claim 5, characterized in that: The output side capacitor voltage data, input side voltage data and input side current data are processed by the meshing control strategy to obtain the phase angle and potential of the meshing control, including: Generate a mechanical torque of the grid-type control according to an initial mechanical torque of the grid-type control and an active power-frequency adjustment signal of the grid-type control; The electromagnetic torque of the grid-type control is calculated according to the three-phase potential, the three-phase reference current and the rated angular velocity of the AC side; The grid-type control damping torque is calculated according to the angular velocity of the AC side, the rated angular velocity of the AC side and the damping coefficient; The angular velocity of the network-type control is obtained according to the mechanical torque, electromagnetic torque and damping torque of the network-type control; Calculate the phase angle of the mesh control according to the mechanical angular velocity of the mesh control; Calculating the reactive power regulation potential and the voltage regulation potential of the grid-type control according to the phase angle of the grid-type control; According to the phase angle and potential of the grid-type control, the three-phase reference current is obtained in combination with the electromagnetic equation.

7. The control method according to claim 4, characterized in that: The quasi-PR controller comprises: Clark transformation module, used to perform Clark transformation on the three-phase reference current and AC side current data to obtain the three-phase current sampling signal and current reference signal of the grid-type control in the two-phase stationary coordinate system; The quasi-PR control module is used to process the three-phase current sampling signal and the current reference signal of the grid-type control to obtain the modulation signal in the αβ coordinate system; The Clark inverse transformation module is used to perform Clark inverse transformation on the modulation signal in the αβ coordinate system to obtain a three-phase modulation wave signal.

8. The control method according to claim 7, characterized in that: The method of controlling the opening and closing of a switch tube in a three-phase rectifier circuit based on the three-phase modulation wave signal comprises: The three-phase modulated wave signal is sent to the PWM modulator to generate a PWM signal, which is used to control the switching of the rectifier module of the AC to DC converter.

9. The control method according to claim 4, characterized in that: The method further comprises: According to the power characteristics of the load, the input side voltage data, the output side voltage data and the current data are processed through double closed-loop control to obtain a modulated wave signal, and the obtained PWM drive signal is interleaved; The switching of the switch tubes in the interleaved parallel Buck circuit is controlled according to the PWM driving signal after interleaving processing to realize voltage regulation control.

10. The control method according to claim 4, characterized in that: The method further comprises: The output voltage is adjusted by the PI of the output voltage outer loop control part to output the current reference value. The output current is adjusted by the PI of the output current inner loop control part to output the modulation wave signal. The modulation wave signal is generated by the PWM modulator to generate the PWM signal. The PWM signal is interleaved to control the switching of each Buck branch switch.

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