Three-phase current type rectifier power supply control method and system for electrolyzing water to produce hydrogen

Abstract

The present invention provides a three-phase current type rectifier power supply control method and system for hydrogen production by electrolysis of water, and relates to the field of power supply control. The method comprises: sectorizing a three-phase input voltage signal to obtain an initial even sector signal and an initial odd sector signal; calculating the number of carrier cycles in the initial even sector signal and the number of carrier cycles in the initial odd sector signal to determine a target carrier frequency; determining an even sector extension time based on the target carrier frequency to generate a target even sector signal and a target odd sector signal, thereby generating a triangular carrier signal; generating a switch drive signal of a three-phase current type rectifier power supply based on the triangular carrier signal and a modulation wave obtained based on the three-phase input voltage signal, and having the advantages of eliminating the distortion of the input current of the three-phase current type rectifier power supply at the sector switching point, reducing the harmonic content of the input current, reducing the output current ripple, and improving the efficiency of the rectifier power supply.

Description

Technical Field

[0001] The invention relates to the field of power supply control, and in particular to a three-phase current type rectifier power supply control method and system for producing hydrogen by electrolyzing water. Background Art

[0002] As a new type of renewable energy, hydrogen energy has the advantages of abundant reserves, high energy density, clean and efficient. Hydrogen production by water electrolysis has received widespread attention due to its excellent environmental protection and hydrogen production performance. In recent years, hydrogen production by water electrolysis has experienced explosive growth. Among them, the hydrogen production power supply is the core device in hydrogen production by water electrolysis. Different hydrogen production power supplies have different effects on the purity, efficiency and service life of the hydrogen produced by electrolysis. The topology of the power supply is of great significance to the efficiency of the hydrogen production system.

[0003] Hydrogen production power sources are divided into two categories according to the source of electricity. For direct current provided by photovoltaic power sources, it is necessary to pass through a DC / DC converter to power the electrolyzer, while for alternating current provided by the power grid or wind turbines, it is necessary to pass through an AC / DC converter to convert the alternating current into direct current to power the electrolyzer. The rectifier link can be divided into two types: current type and voltage type. Among them, the current type rectifier power supply can control the output current more conveniently, and has the advantages of a wide output voltage range, small starting current, and reliable short-circuit current limiting capability. It has been widely used in hydrogen production power sources.

[0004] The existing twelve-sector spatial pulse width modulation method is easy to operate and has low switching loss, and is widely used in current-type rectifier modulation schemes. However, the existing control method causes current distortion at the sector junction due to the irregularity of the driving signal, which makes the input current not a regular sine wave, causing certain harmonic pollution to the input voltage of the previous stage and increasing the output current ripple of the subsequent rectification link, affecting the power transmission effect of the entire circuit.

[0005] Therefore, it is necessary to provide a three-phase current-type rectifier power supply control method and system for hydrogen production by electrolysis of water, which is used to eliminate the distortion of the input current of the three-phase current-type rectifier power supply at the sector switching point, reduce the harmonic content of the input current, reduce the output current ripple, and improve the efficiency of the rectifier power supply. Summary of the invention

[0006] The present invention provides a three-phase current type rectifier power supply control method for producing hydrogen by electrolyzing water, comprising: sectorizing a three-phase input voltage signal to obtain an initial even sector signal and an initial odd sector signal; calculating the number of carrier cycles in the initial even sector signal and the number of carrier cycles in the initial odd sector signal; determining a target carrier frequency based on the number of carrier cycles in the initial even sector signal and the number of carrier cycles in the initial odd sector signal; determining an even sector extension time based on the target carrier frequency; generating a target even sector signal and a target odd sector signal based on the even sector extension time; generating a triangular carrier signal based on the target even sector signal and the target odd sector signal; generating a switch drive signal of a three-phase current type rectifier power supply based on the triangular carrier signal and a modulated wave obtained based on the three-phase input voltage signal.

[0007] Furthermore, the three-phase input voltage signal is sectorized to obtain an initial even sector signal and an initial odd sector signal, including: the moment when the a-phase voltage is maximum and the b-phase and c-phase voltages are equal is the starting point of the initial odd sector signal, and the operation is performed in a manner of dividing the sector signal every 30 degrees to obtain a total of 6 initial odd sector signals and 6 initial even sector signals, and the 6 initial odd sector signals and 6 initial even sector signals are alternately distributed.

[0008] Further, calculating the number of carrier cycles in the initial even sector signal and the number of carrier cycles in the initial odd sector signal includes: calculating the number of carrier cycles in the initial even sector signal and the number of carrier cycles in the initial odd sector signal based on the following formula, D*=[f c * / (12*f in )], where D* is the number of carrier cycles in the initial even sector signal or the number of carrier cycles in the initial odd sector signal, f c * is the rated carrier frequency of the current-type PWM rectifier, f in is the frequency of the three-phase input voltage signal, and [] is the rounding operation.

[0009] Furthermore, based on the number of carrier cycles in the initial even sector signal and the number of carrier cycles in the initial odd sector signal, the target carrier frequency is determined, including: extending the number of carrier cycles in the initial even sector signal by half; and determining the target carrier frequency based on the extended number of carrier cycles in the initial even sector signal and the number of carrier cycles in the initial odd sector signal.

[0010] Further, the target carrier frequency is determined based on the following formula: c =f in *6*(2D*-0.5), where f c is the target carrier frequency.

[0011] Further, based on the target carrier frequency, determining the even sector extension time includes: determining the even sector extension time based on the following formula; t odd =0.5 / f c , where t odd The time is extended for the even sectors.

[0012] Furthermore, the generation of a target even sector signal and a target odd sector signal based on the even sector extension time includes: based on the even sector extension time, extending the initial even sector signal to generate the target even sector signal; based on the even sector extension time, shortening the initial odd sector signal to generate the target odd sector signal.

[0013] Furthermore, based on the target even sector signal and the target odd sector signal, a triangular carrier signal is generated, including: using the target even sector signal as a first control signal to control the counter to generate an even sector triangular carrier signal; using the target odd sector signal as a second control signal to control the counter to generate an odd sector triangular carrier signal.

[0014] Furthermore, based on the triangular carrier signal and the modulation wave obtained based on the three-phase input voltage signal, a switch drive signal of the three-phase current-type rectifier power supply is generated, including: performing a logical OR operation on the even-sector triangular carrier signal and the odd-sector triangular carrier signal to obtain a target carrier signal; comparing the modulation wave signal with the target carrier signal, when the value of the modulation wave signal is greater than the value of the target carrier signal, the switch drive signal is at a high level, and when the value of the modulation wave signal is greater than or equal to the value of the target carrier signal, the switch drive signal is at a low level.

[0015] The present invention provides a three-phase current type rectifier power supply control system for producing hydrogen by electrolyzing water, comprising: a sector division module, used for sectorizing a three-phase input voltage signal to obtain an initial even sector signal and an initial odd sector signal; a period calculation module, used for calculating the number of carrier periods in the initial even sector signal and the number of carrier periods in the initial odd sector signal; a frequency calculation module, used for determining a target carrier frequency based on the number of carrier periods in the initial even sector signal and the number of carrier periods in the initial odd sector signal; a time determination module, used for determining an even sector extension time based on the target carrier frequency; a sector adjustment module, used for generating a target even sector signal and a target odd sector signal based on the even sector extension time; a triangular carrier signal generation module, used for generating a triangular carrier signal based on the target even sector signal and the target odd sector signal; and a switch drive signal generation module, used for generating a switch drive signal of a three-phase current type rectifier power supply based on the triangular carrier signal and a modulation wave obtained based on the three-phase input voltage signal.

[0016] Compared with the prior art, the three-phase current type rectifier power supply control method and system for producing hydrogen by electrolysis of water provided by the present invention have at least the following beneficial effects:

[0017] By using a specific even-sector extended carrier when modulating the current-type PWM rectifier power supply, the existing modulation method completely eliminates the harmonic content of the input side, thereby reducing the harmonic pollution to the front-stage power supply, reducing the output current ripple, and improving the efficiency of the rectifier power supply. The algorithm is simple and easy to implement, without the need for additional hardware equipment, and can effectively reduce the input current harmonic distortion rate of the rectifier, while reducing the output current ripple and improving efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] This specification will be further described in the form of exemplary embodiments, which will be described in detail by the accompanying drawings. These embodiments are not restrictive, and in these embodiments, the same number represents the same structure, wherein:

[0019] Figure 1 It is a flow chart of a three-phase current type rectifier power supply control method for producing hydrogen by electrolysis of water according to some embodiments of this specification;

[0020] Figure 2 is a schematic diagram of carrier signals of a target even sector signal and a target odd sector signal according to some embodiments of this specification;

[0021] Figure 3 is a schematic diagram of an initial even sector signal and an initial odd sector signal according to some embodiments of this specification;

[0022] Figure 4It is a schematic diagram of input three-phase current waveform under the existing modulation method shown in some embodiments of this specification;

[0023] Figure 5 is a schematic diagram of an input three-phase current waveform diagram according to some embodiments of this specification;

[0024] Figure 6 is a schematic diagram of a DC side output current waveform schematic diagram according to some embodiments of this specification;

[0025] Figure 7 It is a module schematic diagram of a three-phase current type rectifier power supply control system for producing hydrogen by electrolysis of water according to some embodiments of this specification;

[0026] Figure 8 It is a structural schematic diagram of a three-phase current-type rectifier power supply control system for producing hydrogen by electrolysis of water according to some embodiments of this specification. DETAILED DESCRIPTION

[0027] In order to more clearly illustrate the technical solutions of the embodiments of this specification, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of this specification. For ordinary technicians in this field, this specification can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0028] Figure 1 is a flow chart of a three-phase current type rectifier power supply control method for producing hydrogen by electrolysis of water according to some embodiments of this specification, such as Figure 1 As shown, a three-phase current-type rectifier power supply control method for producing hydrogen by electrolysis of water may include the following steps.

[0029] Step 110, sectorize the three-phase input voltage signal to obtain an initial even sector signal and an initial odd sector signal.

[0030] In some embodiments, sectorizing the three-phase input voltage signal to obtain an initial even sector signal and an initial odd sector signal includes:

[0031] Figure 3 is a schematic diagram of an initial even sector signal and an initial odd sector signal according to some embodiments of this specification, such as Figure 3As shown, the moment when the voltage of phase a is maximum and the voltages of phases b and c are equal is the starting point of the initial odd sector signal. The operation is performed in a manner of dividing the sector signal into 30 degrees each to obtain a total of 6 initial odd sector signals and 6 initial even sector signals. These 6 initial odd sector signals and 6 initial even sector signals are distributed alternately.

[0032] Specifically, Figure 3 is a schematic diagram of an initial even sector signal and an initial odd sector signal according to some embodiments of this specification, such as Figure 3 As shown, the expression is that when the input voltage is in the even sector, it is a high level and the rest is a low level; when the input voltage is in the odd sector, it is a high level and the rest is a low level.

[0033] Step 120, calculating the number of carrier cycles in the initial even sector signal and the number of carrier cycles in the initial odd sector signal.

[0034] In some embodiments, calculating the number of carrier cycles in the initial even sector signal and the number of carrier cycles in the initial odd sector signal includes:

[0035] The number of carrier cycles in the initial even sector signal and the number of carrier cycles in the initial odd sector signal are calculated based on the following formula,

[0036] D*=[f c * / (12*f in )]

[0037] Where D* is the number of carrier cycles in the initial even sector signal or the number of carrier cycles in the initial odd sector signal, and f c * is the rated carrier frequency of the current-type PWM rectifier, f in is the frequency of the three-phase input voltage signal, and [] is the rounding operation.

[0038] Step 130, determining a target carrier frequency based on the number of carrier cycles in the initial even sector signal and the number of carrier cycles in the initial odd sector signal.

[0039] Figure 2 is a schematic diagram of carrier signals of target even sector signals and target odd sector signals according to some embodiments of this specification, such as Figure 2 As shown, in some embodiments, determining the target carrier frequency based on the number of carrier cycles in the initial even sector signal and the number of carrier cycles in the initial odd sector signal includes:

[0040] Extend the number of carrier cycles in the initial even sector signal by half;

[0041] A target carrier frequency is determined based on the number of carrier cycles in the extended initial even sector signal and the number of carrier cycles in the initial odd sector signal.

[0042] In some embodiments, the target carrier frequency is determined based on the following formula:

[0043] f c =f in *6*(2D*-0.5)

[0044] Among them, f c is the target carrier frequency.

[0045] Step 140: Determine the even sector extension time based on the target carrier frequency.

[0046] In some embodiments, determining an even sector extension time based on a target carrier frequency includes:

[0047] The even sector extension time is determined based on the following formula;

[0048] t odd =0.5 / f c

[0049] Among them, t odd Extend the time for even sectors.

[0050] Step 150: Generate a target even sector signal and a target odd sector signal based on the even sector extension time.

[0051] In some embodiments, generating a target even sector signal and a target odd sector signal based on the even sector extension time includes:

[0052] Based on the even sector extension time, the initial even sector signal is extended, the extension time is the even sector extension time, and a target even sector signal is generated;

[0053] Based on the even sector extension time, the initial odd sector signal is shortened, the shortened time is the even sector extension time, and the target odd sector signal is generated.

[0054] Step 160: Generate a triangular carrier signal based on the target even sector signal and the target odd sector signal.

[0055] In some embodiments, generating a triangular carrier signal based on a target even sector signal and a target odd sector signal includes:

[0056] The target even sector signal is used as the first control signal to control the counter to generate an even sector triangular carrier signal. Specifically, the target even sector signal is used as the first control signal to control the counter to count. The initial counting direction of the counter is increasing. After the count value of the counter reaches the set peak value, the counting direction of the counter is changed to decreasing. After the count value decreases to 0, it is changed to increasing again, and the cycle is repeated to generate an even sector triangular carrier signal.

[0057] The target odd sector signal is used as the second control signal to control the counter to generate an odd sector triangular carrier signal. The specific process is: the target odd sector signal is used as the second control signal to control the counter to count. The initial counting direction of the counter is decreasing. After the counter count value reaches 0, the counting direction of the counter is changed to increasing. After the count value increases to the peak value, it is changed to decreasing again. This cycle is repeated to generate an odd sector triangular carrier signal.

[0058] Step 170 , generating a switch drive signal of a three-phase current source rectifier power supply based on the triangular carrier signal and the modulation wave obtained based on the three-phase input voltage signal.

[0059] In some embodiments, a switch drive signal of a three-phase current-type rectifier power supply is generated based on a triangular carrier signal and a modulation wave obtained based on a three-phase input voltage signal, such as Figure 2 As shown, including:

[0060] Performing a logical OR operation on the even sector triangular carrier signal and the odd sector triangular carrier signal to obtain a target carrier signal;

[0061] The modulation wave signal is compared with the target carrier signal. When the value of the modulation wave signal is greater than the value of the target carrier signal, the switch drive signal is at a high level, turning on the switch tube. When the value of the modulation wave signal is greater than or equal to the value of the target carrier signal, the switch drive signal is at a low level, turning off the switch tube.

[0062] Figure 3 is a schematic diagram of a target even sector signal and a target odd sector signal according to some embodiments of this specification, such as Figure 3 As shown, based on the positional relationship between the carrier signal Ut generated by the three-phase current-type rectifier power supply control method for producing hydrogen by electrolysis of water proposed in the present invention and the sector corresponding to the input voltage, it can be seen that, through the three-phase current-type rectifier power supply control method for producing hydrogen by electrolysis of water proposed in the present invention, the carrier cycle period contained in the target even sector signal is half more than the carrier cycle period contained in the even sector signal of the traditional method, which provides a complete charging and discharging process for the input filter inductor and eliminates current distortion.

[0063] Figure 4 This is the input three-phase current waveform under the existing modulation method. It can be seen from the waveform that at this time, the input current has obvious current distortion at the sector junction and the harmonic content is relatively large. Figure 5 Under the same power, load and circuit topology conditions, the three-phase current waveform is input under the three-phase current type rectifier power supply control method for hydrogen production by electrolysis of water proposed in the present invention. The hardware design and modulation method simulation verification in the specific implementation process show that the current distortion at the sector junction is completely eliminated, the input current is closer to sine, and the harmonic content is small.

[0064] Figure 6 is a schematic diagram of a DC side output current waveform schematic diagram according to some embodiments of this specification, such as Figure 5 As shown, under the same power, load, and circuit topology conditions, the DC side output current waveforms are respectively used using the existing modulation method and the three-phase current-type rectifier power supply control method for hydrogen production by electrolysis of water proposed in the present invention. By comparing the waveforms, it can be obtained that when the three-phase current-type rectifier power supply control method for hydrogen production by electrolysis of water proposed in the present invention is adopted, the output current ripple is smaller, the output power quality is high, and a higher hydrogen production efficiency can be achieved.

[0065] Figure 7 is a module schematic diagram of a three-phase current type rectifier power supply control system for producing hydrogen by electrolysis of water according to some embodiments of this specification, Figure 8 is a schematic diagram of a three-phase current type rectifier power supply control system for producing hydrogen by electrolysis of water according to some embodiments of this specification, such as Figure 7 , 8 As shown, a three-phase current-type rectifier power supply control system for producing hydrogen by electrolysis of water may include a sector division module, a cycle calculation module, a frequency calculation module, a time determination module, a sector adjustment module, a triangular carrier signal generation module, and a switch drive signal generation module.

[0066] The sector division module (SD) can be used to divide the three-phase input voltage signal into sectors to obtain an initial even sector signal and an initial odd sector signal;

[0067] The period calculation module (DNT) may be used to calculate the number of carrier periods in the initial even sector signal and the number of carrier periods in the initial odd sector signal;

[0068] A frequency calculation module (DF) may be used to determine a target carrier frequency based on the number of carrier cycles in the initial even sector signal and the number of carrier cycles in the initial odd sector signal;

[0069] A time determination module (Todd) may be used to determine an even sector extension time based on a target carrier frequency;

[0070] The sector adjustment module (TX) may be used to generate a target even sector signal and a target odd sector signal based on the even sector extension time;

[0071] The triangular carrier signal generation module may be used to generate a triangular carrier signal based on a target even sector signal and a target odd sector signal, wherein the triangular carrier signal generation module may include an even sector triangular carrier signal generation unit (CO) and an odd sector triangular carrier signal generation unit (CE);

[0072] The switch drive signal generating module (CMP) can be used to generate a switch drive signal of a three-phase current type rectifier power supply based on a triangular carrier signal and a modulation wave obtained based on a three-phase input voltage signal.

[0073] The three-phase current-type rectifier power supply control system for producing hydrogen by electrolysis of water can be used to execute the three-phase current-type rectifier power supply control method for producing hydrogen by electrolysis of water. For more descriptions of the three-phase current-type rectifier power supply control system for producing hydrogen by electrolysis of water, please refer to the relevant descriptions of the three-phase current-type rectifier power supply control method for producing hydrogen by electrolysis of water, which will not be repeated here.

[0074] Finally, it should be understood that the embodiments described in this specification are only used to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, as an example and not a limitation, alternative configurations of the embodiments of this specification may be considered consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly introduced and described in this specification.

Claims

1. A three-phase current type rectifier power supply control method for producing hydrogen by electrolysis of water, characterized in that: include: Sectorizing the three-phase input voltage signal to obtain an initial even sector signal and an initial odd sector signal; Calculating the number of carrier cycles in the initial even sector signal and the number of carrier cycles in the initial odd sector signal; Determining a target carrier frequency based on the number of carrier cycles in the initial even sector signal and the number of carrier cycles in the initial odd sector signal; Based on the target carrier frequency, an even sector extension time is determined, wherein the even sector extension time , Extend the time for the even sector, is the target carrier frequency; generating a target even sector signal and a target odd sector signal based on the even sector extension time; generating a triangular carrier signal based on the target even sector signal and the target odd sector signal; Based on the triangular carrier signal and the modulation wave obtained based on the three-phase input voltage signal, a switch drive signal of a three-phase current source rectifier power supply is generated.

2. The three-phase current type rectifier power supply control method for producing hydrogen by electrolysis of water according to claim 1, characterized in that: The sectorizing of the three-phase input voltage signal to obtain an initial even sector signal and an initial odd sector signal includes: The moment when the a-phase voltage is maximum and the b-phase and c-phase voltages are equal is the starting point of the initial odd sector signal. The operation is performed in a manner of dividing the sector signal into 30 degrees to obtain a total of 6 initial odd sector signals and 6 initial even sector signals. The 6 initial odd sector signals and 6 initial even sector signals are distributed alternately.

3. The three-phase current type rectifier power supply control method for producing hydrogen by electrolysis of water according to claim 2, characterized in that: Calculating the number of carrier cycles in the initial even sector signal and the number of carrier cycles in the initial odd sector signal comprises: The number of carrier cycles in the initial even sector signal and the number of carrier cycles in the initial odd sector signal are calculated based on the following formula: ， in, is the number of carrier cycles in the initial even sector signal or the number of carrier cycles in the initial odd sector signal, is the rated carrier frequency of the current-source PWM rectifier, is the frequency of the three-phase input voltage signal, and [ ] is the rounding operation.

4. The three-phase current type rectifier power supply control method for producing hydrogen by electrolysis of water according to claim 3, characterized in that: Determining a target carrier frequency based on the number of carrier cycles in the initial even sector signal and the number of carrier cycles in the initial odd sector signal includes: Extending the number of carrier cycles in the initial even sector signal by half; The target carrier frequency is determined based on the extended number of carrier cycles in the initial even sector signal and the extended number of carrier cycles in the initial odd sector signal.

5. The three-phase current type rectifier power supply control method for producing hydrogen by electrolysis of water according to claim 4, characterized in that: The target carrier frequency is determined based on the following formula: ， in, is the target carrier frequency.

6. The three-phase current type rectifier power supply control method for producing hydrogen by electrolysis of water according to any one of claims 1 to 5, characterized in that: Generating a target even sector signal and a target odd sector signal based on the even sector extension time, including: Based on the even sector extension time, extending the initial even sector signal to generate the target even sector signal; Based on the even sector extension time, the initial odd sector signal is shortened to generate the target odd sector signal.

7. The three-phase current type rectifier power supply control method for producing hydrogen by electrolysis of water according to any one of claims 1 to 5, characterized in that: Generating a triangular carrier signal based on the target even sector signal and the target odd sector signal, comprising: Using the target even sector signal as a first control signal, controlling a counter to generate an even sector triangular carrier signal; The target odd sector signal is used as a second control signal to control the counter to generate an odd sector triangular carrier signal.

8. The three-phase current type rectifier power supply control method for producing hydrogen by electrolysis of water according to claim 7, characterized in that: Based on the triangular carrier signal and the modulation wave obtained based on the three-phase input voltage signal, a switch drive signal of a three-phase current-type rectifier power supply is generated, including: Performing a logical OR operation on the even sector triangular carrier signal and the odd sector triangular carrier signal to obtain a target carrier signal; The modulated wave signal is compared with the target carrier signal. When the value of the modulated wave signal is greater than the value of the target carrier signal, the switch drive signal is at a high level. When the value of the modulated wave signal is greater than or equal to the value of the target carrier signal, the switch drive signal is at a low level.

9. A three-phase current type rectifier power supply control system for producing hydrogen by electrolysis of water, characterized in that: include: A sector division module is used to divide the three-phase input voltage signal into sectors to obtain an initial even sector signal and an initial odd sector signal; A period calculation module, used to calculate the number of carrier periods in the initial even sector signal and the number of carrier periods in the initial odd sector signal; A frequency calculation module, configured to determine a target carrier frequency based on the number of carrier cycles in the initial even sector signal and the number of carrier cycles in the initial odd sector signal; A time determination module is used to determine the even sector extension time based on the target carrier frequency, wherein the even sector extension time , Extend the time for the even sector, is the target carrier frequency; A sector adjustment module, configured to generate a target even sector signal and a target odd sector signal based on the even sector extension time; A triangular carrier signal generating module, configured to generate a triangular carrier signal based on the target even sector signal and the target odd sector signal; The switch drive signal generating module is used to generate a switch drive signal of a three-phase current type rectifier power supply based on the triangular carrier signal and a modulation wave obtained based on the three-phase input voltage signal.

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