Hydrogen production power supply system and control method thereof

Abstract

The present application discloses a hydrogen production power supply system and a control method thereof, wherein the hydrogen production power supply system includes a transformer unit, a voltage regulating unit, a connection unit and a power unit, wherein the transformer unit outputs a first AC signal and a second AC signal; the voltage regulating unit adjusts the second AC signal to obtain an adjusted AC signal; the connection unit connects the first AC signal and the adjusted AC signal to obtain a target AC signal; and the power unit converts the target AC signal into a target DC signal, so that the target DC signal supplies power to the electrolyzer. The signal parameters of the adjusted AC signal of the present application are related to the power supply requirements of the hydrogen production electrolyzer, and the output range of the target DC signal output by the power unit is zero to the rated value. The hydrogen production power supply system of the present application can determine the size of the adjusted AC signal according to the power supply requirements of the electrolyzer, meet the voltage requirements of the electrolyzer under different working conditions, and improve the energy conversion efficiency of the power supply.

Description

Technical Field

[0001] The present application relates to the technical field of hydrogen production power supply circuits, and in particular to a hydrogen production power supply system and a control method thereof. Background Art

[0002] With the development of new energy technologies, hydrogen, as a clean and efficient energy source, has broad application prospects. Water electrolysis is a common method for producing hydrogen. In this process, a hydrogen power supply is installed between the power grid and the electrolyzer. The power supply converts AC power from the grid and outputs it to the electrolyzer, where it generates hydrogen through an electrolysis reaction.

[0003] Existing hydrogen production power supply technology solutions usually use a primary topology circuit or a secondary topology circuit for energy conversion to meet the power supply needs of the electrolyzer. However, the energy conversion circuit of the primary topology structure will inject a large amount of low-order harmonics into the AC power grid and absorb a large amount of reactive power. The output DC voltage regulation speed is slow and contains a large amount of current ripple, which affects the efficiency of hydrogen production by the electrolyzer and is not suitable for application in the field of green electricity hydrogen production. When the secondary topology circuit is used for rectification and power supply, multiple branches are usually required to be connected in parallel to supply power to meet the current and voltage requirements of the electrolyzer. The existence of multiple branches supplying power at the same time affects the overall efficiency of the hydrogen production power supply, especially under conditions where the hydrogen production of the electrolyzer is low, the efficiency is not high.

[0004] To improve the energy conversion efficiency of hydrogen production power supplies and optimize their grid-connected characteristics, a rectifier circuit with only one energy conversion stage can be used to construct a hydrogen production power supply. However, the DC voltage output of existing IGBT-based PWM rectifier circuits can only exceed the amplitude of their AC line voltage, making them inoperable during electrolyzer startup and during low- to medium-level hydrogen production conditions. Summary of the Invention

[0005] An embodiment of the present application provides a hydrogen production power supply system and a control method thereof, which adopts a primary circuit with only one energy conversion to form a hydrogen production power supply system, which can meet the voltage requirements of the electrolyzer under different working conditions such as electrolyzer startup and medium and low hydrogen production, thereby improving the energy conversion efficiency of the power supply.

[0006] In order to achieve the above objectives, according to a first aspect of the present application, a hydrogen production power supply system is proposed, the system comprising:

[0007] A voltage transformation unit, configured to determine a first AC signal and a second AC signal according to a power grid AC signal;

[0008] a voltage regulating unit connected to the voltage transforming unit, and configured to adjust the second AC signal to obtain an adjusted AC signal;

[0009] a connecting unit connected to the voltage transformation unit and the voltage regulation unit, and configured to connect the first AC signal and the adjusted AC signal to obtain a target AC signal;

[0010] A power unit, connected to the connection unit, is used to convert the target AC signal into a target DC signal so that the target DC signal powers the hydrogen-producing electrolyzer; wherein the signal parameters of the adjusted AC signal are related to the power supply requirements of the hydrogen-producing electrolyzer, and the output range of the target DC signal is zero to a rated value.

[0011] Optionally, the power unit includes a plurality of primary rectifier units connected in parallel.

[0012] Optionally, the primary rectifier unit includes an AC-DC conversion circuit.

[0013] Optionally, the primary rectifier unit further includes a series inductor, and the series inductor is used to connect the target AC signal and the AC-DC conversion circuit.

[0014] Optionally, the AC-DC conversion circuit is further used to perform reactive power compensation and harmonic suppression on the AC power grid.

[0015] Optionally, the voltage regulating unit includes an AC-DC conversion circuit and a DC-AC conversion circuit, wherein:

[0016] The AC-DC conversion circuit is used to convert the second AC signal into a first DC signal;

[0017] The DC-AC conversion circuit is used to convert the first DC signal into the adjusted AC signal.

[0018] Optionally, the AC-DC conversion circuit includes a three-phase bridge circuit based on switching elements; and / or the DC-AC conversion circuit includes a three-phase bridge circuit based on switching elements.

[0019] Optionally, the AC-DC conversion circuit includes a rectifier circuit based on diodes.

[0020] Optionally, the connection unit includes a connection transformer, the secondary winding of the connection transformer is respectively connected to the output end of the transformation unit and the input end of the power unit, and the primary winding of the connection transformer is connected to the output end of the voltage regulation unit.

[0021] According to a second aspect of the present application, a hydrogen production power supply control method is provided, comprising:

[0022] determining a first AC signal and a second AC signal according to the power grid AC signal;

[0023] adjusting the second AC signal to obtain an adjusted AC signal;

[0024] connecting the first AC signal and the adjusted AC signal to obtain a target AC signal;

[0025] The target AC signal is converted into a target DC signal so that the target DC signal powers the hydrogen production electrolyzer; wherein the signal parameters of the adjusted AC signal are related to the power supply requirements of the hydrogen production electrolyzer, and the output range of the target DC signal is zero to a rated value.

[0026] In summary, the hydrogen production power supply system of the present application includes a transformer unit, a voltage regulating unit, a connection unit and a power unit. The voltage regulating unit and the connection unit are both connected to the transformer unit, and the power unit is also connected to the connection unit. The transformer unit outputs a first AC signal and a second AC signal; the voltage regulating unit adjusts the second AC signal to obtain an adjusted AC signal; the connection unit connects the first AC signal and the adjusted AC signal to obtain a target AC signal. The power unit receives the target AC signal output by the connection unit, and converts the target AC signal into a target DC signal to power the hydrogen production electrolyzer through the target DC signal. The signal parameters of the adjusted AC signal in the embodiment of the present application are related to the power supply requirements of the hydrogen production electrolyzer, and the output range of the target DC signal output by the power unit is zero to the rated value.

[0027] The hydrogen production power supply system of the present application can use a small-capacity voltage regulating unit to adjust the target AC signal of the input power unit according to the load characteristics of the hydrogen production electrolyzer when the hydrogen production electrolyzer is started and under medium and low hydrogen production conditions, thereby enabling the PWM rectifier circuit containing only one level of energy conversion link to achieve a low DC voltage output to meet the voltage requirements of the hydrogen production electrolyzer under medium and low working conditions; under medium and high hydrogen production conditions, the voltage regulating unit can be bypassed, and the power unit can only supply power to the hydrogen production electrolyzer through the first AC signal output by the transformer unit. The embodiment of the present application can meet the hydrogen production electrolyzer's demand for voltage regulation of the hydrogen production power supply output voltage from zero to the rated value at a relatively low cost, thereby improving the energy conversion efficiency of the hydrogen production power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic diagram of a hydrogen production power supply system provided in an embodiment of the present application;

[0029] Figure 2 This is a schematic diagram of a two-level three-phase bridge circuit provided in an embodiment of the present application;

[0030] Figure 3 This is a schematic diagram of a level three-phase bridge circuit provided by an embodiment of the present application;

[0031] Figure 4Schematic diagram of a power unit including a two-level three-phase bridge circuit provided in an embodiment of the present application;

[0032] Figure 5 This is a schematic diagram of a diode-based rectifier circuit provided in an embodiment of the present application;

[0033] Figure 6 is a circuit diagram of a connection unit provided in an embodiment of the present application;

[0034] Figure 7 This is a flow chart of a hydrogen production power supply control method provided in an embodiment of the present application;

[0035] Figure 8 This is a schematic diagram of the voltage vector relationship provided in an embodiment of the present application. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0037] In addition, the term "plurality" in the embodiments of the present application refers to two or more. The terms "first" and "second" in the embodiments of the present application are used to distinguish different technical features and do not indicate any order, quantity, or importance. The terms "include" and "comprising" in the embodiments of the present application indicate the presence of the described features, entities, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, entities, steps, operations, elements, components, and / or combinations thereof.

[0038] The various embodiments provided in this application are similar, and features in different embodiments may be combined with each other.

[0039] The order in which the following embodiments are described is not intended to limit the preferred order of the embodiments.

[0040] Hydrogen energy is a clean, carbon-free, flexible, efficient, and diversely applicable secondary energy source and an important industrial raw material. Hydrogen production by water electrolysis is a commonly used method for producing hydrogen. It is environmentally friendly, flexible in production, and high in purity, making it an ideal green hydrogen production method. As the core equipment connecting the electrolyzer and the new energy grid, the control performance and reliability of the hydrogen production power system are directly related to the efficiency and safety of the entire hydrogen production system. If the existing hydrogen production power system uses a primary topology energy conversion circuit, it will inject a large amount of low-order harmonics into the AC grid, absorb a large amount of reactive power, and have a slow output DC voltage regulation speed and contain a large amount of current ripple, affecting the hydrogen production efficiency of the hydrogen production electrolyzer. When a secondary topology circuit is used for rectification and power supply, multiple branches need to be connected in parallel to meet the current and voltage requirements of the electrolyzer. The presence of multiple branches supplying power at the same time affects the overall efficiency of the hydrogen production power supply, especially under conditions where the hydrogen production of the electrolyzer is low.

[0041] In response to the above problems, Figure 1 As shown, the present application provides a hydrogen production power supply system, which includes a transformer unit 100, a voltage regulating unit 200, a connection unit and a power unit 300. The voltage regulating unit 200 and the connection unit are both connected to the transformer unit 100, and the power unit 300 is connected to the connection unit. Among them, the transformer unit 100 outputs a first AC signal and a second AC signal. The voltage regulating unit 200 adjusts the second AC signal to obtain an adjusted AC signal. The connection unit connects the first AC signal with the adjusted AC signal to obtain a target AC signal. The power unit 300 converts the target AC signal into a target DC signal so that the target DC signal supplies power to the hydrogen production electrolyzer. Among them, the signal parameters of the adjusted AC signal are related to the power supply requirements of the hydrogen production electrolyzer, and the output range of the target DC signal is zero to the rated value.

[0042] like Figure 1 As shown, the transformer unit 100 can be a three-winding isolation transformer. The primary winding of the three-winding isolation transformer is connected to the AC grid for receiving the grid AC signal. The first secondary winding of the three-winding isolation transformer is connected to the power unit 300, and the second secondary winding is connected to the voltage regulating unit 200. The target DC signal is represented by u out , the vector representation of the target AC signal is , with u out Related, the vector representation of the regulated AC signal is , the vector representation of the first AC signal is Since the target DC signal outputted in this embodiment is used to power the electrolyzer, the AC signal can be adjusted according to the power supply demand of the hydrogen production electrolyzer. , so that the first AC signal vector Can be combined Adjust to get the target AC signal ,Right now .

[0043] The hydrogen production power supply system of this embodiment can adjust the size of the AC signal according to the power supply demand of the electrolyzer to meet the voltage requirements under different working conditions and improve the energy conversion efficiency of the power supply.

[0044] The signal parameters of the adjusted AC signal may be parameters such as amplitude and phase. The magnitude of the adjusted AC signal in the embodiment of the present application is related to the power supply requirements of the electrolytic cell.

[0045] The power supply requirement characterizes the voltage required by the electrolyzer for hydrogen production. To ensure efficient hydrogen production, the target DC signal output by the hydrogen production power system must meet the electrolyzer's power supply requirements.

[0046] For example, when the electrolyzer is started or is in a medium or low hydrogen production condition, a lower target DC signal is required, and thus a lower target AC signal is required. Since the target AC signal is related to the first AC signal and the regulated AC signal, the regulated AC signal output by the voltage regulating unit can be reduced to obtain a lower target AC signal, and then the PWM rectifier circuit containing only one level of energy conversion link can output a lower target DC signal, thereby meeting the voltage requirements of the electrolyzer in medium and low working conditions. For another example, when the first AC signal can meet the power supply requirements of the electrolyzer, the regulated AC signal output by the voltage regulating unit can be bypassed, and the target DC signal can be obtained only by converting the power unit according to the first AC signal. The embodiment of the present application can meet the voltage regulation requirements of the hydrogen production electrolyzer for the output voltage of the hydrogen production power supply from zero to the rated value at a lower cost, thereby improving the energy conversion efficiency of the hydrogen production power supply system.

[0047] In some specific embodiments, the power unit 300 includes several primary rectifier units connected in parallel.

[0048] The primary rectifier unit is used to characterize the rectifier unit with a primary topology. The primary rectifier unit is used to convert the target AC signal to obtain the target DC signal. Please continue to refer to Figure 1 The positive and negative poles of the output terminals of the first-level rectifier units connected in parallel are connected to the positive and negative poles of the input terminals of the electrolytic cell respectively. The power unit 300 of this embodiment includes a plurality of first-level rectifier units connected in parallel. The DC signal output by each first-level rectifier unit can be expressed as u dc , connect the rectifier units in parallel to dc Get the target DC signal u out , in order to meet the power supply demand of the electrolyzer by connecting multiple primary rectifier units in parallel.

[0049] This embodiment performs AC / DC conversion through parallel-connected primary rectifier units, and the primary topology circuit only has one energy conversion. The circuit structure is simple, which can improve the energy conversion efficiency and thus improve the hydrogen production efficiency of the hydrogen production power supply system.

[0050] In some further embodiments, the primary rectifier unit includes an AC-DC conversion circuit.

[0051] AC-DC converter circuits are diode- or thyristor-based circuits that utilize pulse-width modulation (PWM) technology for rectification. PWM rectifier circuits use PWM technology to adjust the on and off times of switches, thereby converting AC signals into DC signals. Diode or thyristor rectifier circuits utilize the unidirectional conductivity of diodes or thyristors to achieve conversion from AC to DC signals.

[0052] Please continue reading Figure 1 In some embodiments, the primary rectifier unit further includes a series inductor, which is used to connect the target AC signal and the AC-DC conversion circuit. The series inductor is arranged between the target AC signal and the AC-DC conversion circuit to raise the voltage value of the target DC signal output on the DC side, and to smooth the target AC signal input to the power unit, thereby reducing the ripple in the target DC signal. In the embodiment of the present application, the series inductor in the primary rectifier unit suppresses the high-frequency component by the impedance effect on the current change, thereby reducing the output ripple and improving the output DC quality.

[0053] In some embodiments, the AC-DC conversion circuit is further configured to perform reactive power compensation and harmonic suppression on the AC power grid.

[0054] Reactive power compensation is the process of controlling or compensating for reactive power in the AC power grid through AC-DC conversion circuits. Reactive power is the portion of power in a power system that cannot be directly converted into useful work. Reactive power compensation can improve voltage quality, increase energy transmission efficiency, and reduce system losses. Harmonics are high-frequency signals in current and voltage waveforms, typically caused by nonlinear loads. Harmonic signals can negatively impact the interaction between devices in the power system. Harmonic mitigation can minimize equipment damage, improve power quality, reduce nonlinear system losses, and ensure proper operation and high efficiency of power equipment.

[0055] The AC-DC conversion circuit of this embodiment is a primary rectifier circuit based on PWM. The primary rectifier circuit based on PWM has the advantages of high power factor, few grid-connected harmonics, and fast response speed, and can provide additional functions such as reactive power compensation and harmonic suppression to the AC power grid.

[0056] In some embodiments, the voltage regulating unit 200 includes an AC-DC conversion circuit and a DC-AC conversion circuit. The AC-DC conversion circuit is used to convert the second AC signal into a first DC signal, and the DC-AC conversion circuit is used to convert the first DC signal into the adjusted AC signal.

[0057] Please continue reading Figure 1 The voltage regulating unit 200 is connected to the second secondary winding of the transformer unit 100 and receives the second AC signal output by the transformer unit 100. The voltage regulating unit 200 converts the second AC signal into a first DC signal through an AC-DC conversion circuit. The positive and negative poles of the first DC signal are respectively connected to the positive and negative poles of the DC input terminal of the DC-AC conversion circuit, and then the first DC signal is converted by the DC-AC conversion circuit to obtain an adjusted AC signal, so as to convert the first DC signal into an adjusted AC signal with adjustable amplitude, phase and frequency. The output end of the DC-AC conversion circuit is connected to the connecting unit so that the connecting unit can obtain a target AC signal based on the adjusted AC signal and the first AC signal, and output the target AC signal to the power unit 300.

[0058] The voltage regulator unit 200 determines the required voltage of the hydrogen production power system based on the operating conditions of the electrolyzer. It then adjusts the AC signal output by the voltage regulator unit 200 and combines it with the first AC signal output by the transformer unit 100 to generate a target AC signal. This allows the target DC signal output by the power unit 300 based on the target AC signal to meet the required voltage of the electrolyzer.

[0059] In some embodiments, the AC-DC conversion circuit includes a three-phase bridge circuit based on switching elements; and / or the DC-AC conversion circuit includes a three-phase bridge circuit based on switching elements.

[0060] A switching element is a component in a circuit that controls the flow of current. By controlling the flow of electrical energy through a switching element, the circuit's operating state can be precisely adjusted or the direction of current can be changed. The switching element in this embodiment can be a fully controlled device such as an insulated gate bipolar transistor (IGBT), an insulated gate commutated thyristor (IGCT), or a gate turn-off thyristor (GTO).

[0061] The three-phase bridge circuit can be a two-level three-phase bridge circuit or a three-level three-phase bridge circuit. Both the two-level three-phase bridge circuit and the three-level three-phase bridge circuit are circuits used to realize PWM rectification or inversion functions. Figure 2The two-level three-phase bridge circuit shown in the figure includes two switching elements per phase. The three-phase bridge circuit is formed by six switching elements. The state of each switching element includes open or closed, and the corresponding output voltage signal includes positive voltage or negative voltage. Figure 3 The three-level three-phase bridge circuit shown includes four switching elements per phase. The three-phase bridge circuit is formed by twelve switching elements. The voltage signal outputted by each switching element includes a positive voltage, a zero voltage or a negative voltage.

[0062] Figure 4 The power unit 300 is shown as a two-level three-phase bridge circuit. Figure 4 In the power unit 300 shown, each primary rectifier unit realizes AC-DC signal conversion through a two-level three-phase bridge circuit and an inductor connected in series with the two-level three-phase bridge circuit.

[0063] In other embodiments, Figure 5 As shown, the AC-DC conversion circuit includes a rectifier circuit based on diodes.

[0064] Please refer to Figure 5 The AC-DC conversion circuit in the primary rectifier unit is configured as a diode-based rectifier circuit. Diode rectifier circuits utilize the unidirectional conductivity of diodes to convert AC signals to DC signals. When the AC current flows in the same direction as the diode, the current flows through the diode. This diode-based rectifier circuit requires no external control or human intervention, further reducing the cost of the hydrogen production power system.

[0065] In some other embodiments, such as Figure 6 As shown, the connecting unit is connected to both the voltage regulating unit 200 and the power unit 300 , and is used to transmit the harmonic voltage generated by the voltage regulating unit 200 to the power unit 300 .

[0066] The voltage regulating unit 200 of this embodiment is connected to the power unit 300. The voltage regulating unit 200 can also generate a harmonic voltage based on the voltage ripple of the DC signal output by the power unit 300. The harmonic voltage is input to the AC side of the power unit 300 through the connecting unit, thereby suppressing the voltage ripple output on the DC side of the power unit 300.

[0067] In some embodiments, the connection unit includes a connection transformer. The connection transformer is a two-winding transformer, see Figure 6The secondary winding of the connecting transformer is disposed between the transformer unit 100 and the power unit 300, and the primary winding of the connecting transformer is connected to the output terminal of the voltage regulating unit 200. Exemplarily, the primary winding of the connecting transformer is connected to the output terminal of the voltage regulating unit 200 in a star connection manner, so that the regulated AC signal output by the voltage regulating unit 200 is input to the connecting unit.

[0068] In some embodiments, a method for controlling a hydrogen production power supply is provided, comprising:

[0069] Step S701: determining a first AC signal and a second AC signal according to a power grid AC signal.

[0070] The transformer unit 100 includes a three-winding isolation transformer. The primary winding of the isolation transformer receives an AC signal from an AC grid, outputs a first AC signal at a first secondary winding, and outputs a second AC signal at a second secondary winding.

[0071] Step S702: adjust the second AC signal to obtain an adjusted AC signal.

[0072] The voltage regulating unit 200 is connected to the second secondary winding of the three-winding isolation transformer in the transformer unit 100 , receives the second AC signal output by the isolation transformer, and adjusts the second AC signal to obtain an adjusted AC signal.

[0073] Combine Figure 1 As shown, voltage regulation unit 200 includes an AC-DC conversion circuit and a DC-AC conversion circuit. Voltage regulation unit 200 first converts the second AC signal in the AC-DC conversion circuit to obtain a first DC signal, and then converts the first DC signal in the DC-AC conversion circuit to obtain an adjusted AC signal. Voltage regulation unit 200 converts the first DC signal into an adjusted AC signal with adjustable amplitude, phase, and frequency based on the required voltage of the electrolyzer.

[0074] Step S703: Connect the first AC signal and the adjusted AC signal to obtain a target AC signal.

[0075] The connection unit connects the outputs of the transformer unit 100 and the voltage regulator unit 200 to generate a target AC signal so that the power unit 300 can output a target DC signal according to the target AC signal to meet the required voltage of the electrolytic cell.

[0076] Step S704, converting the target AC signal into a target DC signal so that the target DC signal powers the hydrogen production electrolyzer; wherein, adjusting the signal parameters of the AC signal is related to the power supply requirement of the hydrogen production electrolyzer, and the output range of the target DC signal is zero to a rated value.

[0077] The target DC signal u output by the power unit 300 in this embodiment is dcAC signal amplitude with the target U srm Satisfaction between The amplitude of the first AC signal is represented by U grm , when the required voltage of the electrolyzer , indicating that the first AC signal cannot meet the required voltage of the electrolytic cell after AC-DC conversion, and it is necessary to combine the first AC signal with the regulated AC signal to obtain the target AC signal. At this time, the voltage u output by the power unit 300 is dc Setting value .

[0078] When the required voltage of the electrolytic cell , indicating that the first AC signal can meet the required voltage of the electrolytic cell after AC-DC conversion. At this time, the voltage u output by the power unit 300 is dc The setting value u dcref =u out .

[0079] The following combination Figure 8 The relationship between the three voltage vectors of the power unit 300 is described in detail. Figure 8 As shown, the vector representation of the target AC signal is , the vector representation of the regulated AC signal is , the vector representation of the first AC signal is .

[0080] like Figure 8 As shown, when the three voltage vectors satisfy Figure 8 When the relationship shown in (a) is met, the voltage regulating unit 200 needs to inject reactive power into the transformer unit 100 while feeding active power back to the grid. Figure 8 When the relationship shown in (b) is met, the voltage regulating unit 200 only needs to return active power to the AC grid. Figure 8 In the relationship shown in (c), the voltage regulating unit 200 needs to inject active power into the power unit 300 , and the first secondary winding and the second secondary winding of the transformer unit 100 simultaneously supply energy to the power unit 300 .

[0081] In some embodiments, a control method for a hydrogen production power system is described in detail. The control method includes the following steps:

[0082] Step 901: unlock the AC-DC conversion circuit of the voltage regulating unit 200 to provide a DC voltage source for the DC-AC conversion circuit;

[0083] Step 902: Determine the DC voltage u that needs to be applied to both ends of the electrolytic cell according to the operating conditions of the electrolytic cell. out ;

[0084] Step 903, when it indicates that the first AC signal cannot meet the required voltage of the electrolytic cell after AC-DC conversion, and it is necessary to combine the first AC signal with the adjusted AC signal to obtain the target AC signal.

[0085] Let the voltage target value u dcref = u out of the target DC signal output by the power unit 300, and calculate the voltage amplitude ;

[0086] Step 904, according to the difference relationship between the voltage amplitude of the target AC signal of the power unit 300 and the voltage amplitude of the first secondary winding output phase voltage of the transformer unit 100, confirm that the amplitude △U of the adjusted AC signal vector output by the voltage regulating unit 200 satisfies the relationship △U = 丨 U srm - U grm 丨;

[0087] Step 905, assume that the phase angle of the voltage vector output by the first secondary winding of the transformer unit 100 is θ g , when the phase angle θ of the adjusted AC signal vector △ output by the voltage regulating unit 200 = π + θ g ; when U srm - U grm > 0, the phase angle θ of the adjusted AC signal vector △ output by the auxiliary voltage regulating circuit = θ g ;

[0088] Step 906, according to the amplitude △U and phase angle θ of the adjusted AC signal vector, control the DC-AC conversion circuit in the voltage regulating unit 200 to output the adjusted AC signal vector △ ; ;

[0089] Step 907, when it indicates that the first AC signal can meet the required voltage of the electrolytic cell after AC-DC conversion.

[0090] Let the set value u dc of the voltage u dcref output by the power unit 300 for the target DC signal uout , the regulated AC signal vector output by the voltage regulating unit 200 The amplitude △U and phase angle θ △ All are set to zero, and all fully controlled devices of the three-phase upper bridge arm or lower bridge arm of the converter in the DC-AC conversion circuit are turned on to bypass the voltage regulation unit 200.

[0091] Step 908: The power unit 300 controls the parallel-connected primary rectifier units to output the target DC voltage. u dcref , to meet the power supply requirements of the electrolyzer's target operating conditions.

[0092] The hydrogen production power supply system of this embodiment can determine the power supply demand according to the load characteristics of the electrolyzer, and then adjust the size of the AC signal to meet the voltage requirements under different working conditions. In the hydrogen production power supply control method of the embodiment of the present application, when the hydrogen production electrolyzer is started or under the working conditions of medium and low hydrogen production, a small-capacity voltage regulating unit can be used to adjust the target AC signal of the input power unit 300, so that the PWM rectifier circuit containing only one-stage energy conversion link can achieve low DC voltage output to meet the voltage requirements of the medium and low working conditions of the hydrogen production electrolyzer; under medium and high hydrogen production conditions, the voltage regulating unit can be bypassed, and the power unit can supply power to the hydrogen production electrolyzer only through the first AC signal output by the transformer unit. The embodiment of the present application can meet the hydrogen production electrolyzer's demand for voltage regulation of the hydrogen production power supply output voltage from zero to an additional value at a relatively low cost, thereby improving the energy conversion efficiency of the power supply.

[0093] It should be understood that the above-mentioned hydrogen production power supply system control method is a method embodiment corresponding to the above-mentioned hydrogen production power supply system. For a detailed introduction to the various steps in the hydrogen production power supply system control method and their beneficial effects, please refer to the embodiment of the above-mentioned hydrogen production power supply system, which will not be elaborated here.

[0094] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0095] The above is a detailed introduction to a hydrogen production power supply system and a hydrogen production power supply control method provided in the embodiments of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for technical personnel in this field, based on the ideas of the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A hydrogen production power supply system, characterized in that: The system comprises: A voltage transformation unit, configured to determine a first AC signal and a second AC signal according to a power grid AC signal; a voltage regulating unit connected to the voltage transforming unit, configured to adjust the second AC signal to obtain an adjusted AC signal; a connecting unit connected to the voltage transforming unit and the voltage regulating unit, configured to connect the first AC signal and the adjusted AC signal to obtain a target AC signal; a power unit connected to the connection unit, configured to convert the target AC signal into a target DC signal, so that the target DC signal supplies power to the hydrogen-producing electrolyzer; wherein the signal parameters of the adjusted AC signal are related to the power supply requirements of the hydrogen-producing electrolyzer, and the output range of the target DC signal is zero to a rated value; The power unit includes a plurality of PWM-based primary rectifier units connected in parallel, each of which includes an AC-DC conversion circuit, and the AC-DC conversion circuit is further used to perform reactive power compensation and harmonic suppression on the AC power grid; The primary rectifier unit also includes a series inductor, which is used to connect the target AC signal and the AC-DC conversion circuit. The series inductor is used to raise the voltage value of the target DC signal output on the DC side and smooth the target AC signal input to the power unit.

2. The hydrogen production power supply system according to claim 1, characterized in that: The voltage regulating unit includes an AC-DC conversion circuit and a DC-AC conversion circuit, wherein: The AC-DC conversion circuit is used to convert the second AC signal into a first DC signal; The DC-AC conversion circuit is used to convert the first DC signal into the adjusted AC signal.

3. The hydrogen production power supply system according to claim 1 or 2, characterized in that: The AC-DC conversion circuit includes a three-phase bridge circuit based on switching elements; and / or the DC-AC conversion circuit includes a three-phase bridge circuit based on switching elements.

4. The hydrogen production power supply system according to claim 1 or 2, characterized in that: The AC-DC conversion circuit includes a rectifier circuit based on diodes.

5. The hydrogen production power supply system according to claim 1, characterized in that: The connecting unit includes a connecting transformer, the secondary winding of the connecting transformer is respectively connected to the output end of the voltage transformation unit and the input end of the power unit, and the primary winding of the connecting transformer is connected to the output end of the voltage regulation unit.

6. A hydrogen production power supply control method, characterized in that: Applied to the hydrogen production power supply system according to any one of claims 1 to 5, the method comprises: determining a first AC signal and a second AC signal according to the power grid AC signal; adjusting the second AC signal to obtain an adjusted AC signal; connecting the first AC signal and the adjusted AC signal to obtain a target AC signal; The target AC signal is converted into a target DC signal so that the target DC signal powers the hydrogen production electrolyzer; wherein the signal parameters of the adjusted AC signal are related to the power supply requirements of the hydrogen production electrolyzer, and the output range of the target DC signal is zero to a rated value.

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