Hydrogen production power supply voltage detection circuit, hydrogen production system and control method

Abstract

The application discloses a kind of voltage detection circuit of hydrogen production power supply, hydrogen production system and control method, it is related to hydrogen production technical field.The voltage detection circuit includes: first sampling circuit, with the positive output end of the hydrogen production power supply is connected, for obtaining the first voltage of the positive output end;Second sampling circuit, with the negative output end of the hydrogen production power supply is connected, for obtaining the second voltage of the negative output end;Detection unit is connected with the first sampling circuit and the second sampling circuit respectively, for determining fault state according to the first voltage or the second voltage;So as to determine whether there is ground fault according to the voltage value of the positive and negative output end of hydrogen production power supply, it can also be judged that output positive end short circuit or negative end short circuit, simple structure is easy to realize.

Description

Technical Field

[0001] This invention relates to the field of hydrogen production technology, and in particular to a voltage detection circuit for a hydrogen production power supply, a hydrogen production system, and a control method. Background Technology

[0002] Alkaline water electrolysis for hydrogen production typically consists of a varying number of electrolysis cells connected in series; for example, a 1000 Nm³ / h electrolysis cell may consist of 350 cells, each bearing 1 / 350 of the input voltage. Furthermore, it usually employs an intermediate electrode grounding method to prevent static electricity buildup within the electrolysis cell. Currently, the hydrogen production power supply equipment and the electrolysis cell are typically connected via wires or copper busbars; however, the insulation of wires is prone to aging and damage, and copper busbar connections inevitably carry the risk of short circuits to ground. With intermediate electrode grounding, if a short circuit occurs to ground at any point in the positive or negative transmission circuit connecting the aforementioned connections, 50% of the electrolysis cells in the cell will be short-circuited, while the remaining 50% will bear twice the normal voltage, significantly impacting the performance and lifespan of the electrolysis cell. Simultaneously, the large current at the short circuit point can cause insulation overheating and fire, potentially leading to serious consequences near the electrolysis cell. Therefore, how to detect this type of fault is a technical problem that urgently needs to be solved. Summary of the Invention

[0003] The main objective of this invention is to provide a voltage detection circuit for a hydrogen production power supply, a hydrogen production system, and a control method, aiming to solve the technical problem of equipment damage caused by grounding faults in the power supply circuit of hydrogen electrolyzers in the prior art.

[0004] To achieve the above objectives, this invention proposes a voltage detection circuit for a hydrogen production power supply, wherein the hydrogen production power supply is connected to an electrolyzer, the intermediate electrode plate of the electrolyzer is grounded, and the voltage detection circuit includes:

[0005] The first sampling circuit is connected to the positive output terminal of the hydrogen production power supply and is used to obtain the first voltage of the positive output terminal.

[0006] The second sampling circuit is connected to the negative output terminal of the hydrogen production power supply and is used to obtain the second voltage of the negative output terminal.

[0007] The detection unit is connected to the first sampling circuit and the second sampling circuit respectively, and is used to determine the fault status of the hydrogen production power supply based on the first voltage or the second voltage.

[0008] Optionally, the first sampling circuit includes:

[0009] A first voltage divider unit and a second voltage divider unit are connected in series. One end of the first voltage divider unit is connected to the positive output terminal of the hydrogen production power supply, and one end of the second voltage divider unit is grounded.

[0010] An operational amplifier unit is provided, wherein the input terminal of the operational amplifier unit is connected to the connection point of the first voltage divider unit and the second voltage divider unit, and the output terminal of the operational amplifier unit is connected to the detection unit.

[0011] Optionally, the first voltage divider unit includes a first resistor, and the second voltage divider unit includes a second resistor.

[0012] Optionally, the operational amplifier unit includes:

[0013] The first operational amplifier has its inverting input connected to the connection point via a third resistor, its output connected to the first operational amplifier via a fourth resistor, its non-inverting input grounded via a fifth resistor, and its output connected to the detection unit.

[0014] Optionally, the voltage detection circuit further includes:

[0015] A differential calculation unit is connected to the first sampling circuit and the second sampling circuit respectively, and is used to perform differential calculation on the first voltage and the second voltage to obtain a third voltage;

[0016] The detection unit is also connected to the differential calculation unit and is used to determine the output voltage of the hydrogen production power supply based on the third voltage.

[0017] Optionally, the difference calculation unit includes:

[0018] The second operational amplifier has its non-inverting input connected to the first sampling circuit via a sixth resistor, its output connected to the second operational amplifier via a seventh resistor, its inverting input connected to the first sampling circuit via an eighth resistor, its non-inverting input grounded via a ninth resistor, and its output connected to the detection unit.

[0019] Optionally, the detection unit includes:

[0020] The conditioning unit is connected to the first sampling circuit and the second sampling circuit respectively, and is used to condition the first voltage and the second voltage;

[0021] A digital-to-analog converter unit, connected to the conditioning unit, is used to convert the conditioned first voltage to obtain first voltage data, and to convert the conditioned second voltage to obtain second voltage data;

[0022] The controller, connected to the digital-to-analog conversion unit, is used to determine the fault state based on the first voltage data or the second voltage data.

[0023] To achieve the above objectives, the present invention also proposes a hydrogen production system, the hydrogen production system comprising:

[0024] Hydrogen production power source;

[0025] An electrolyzer is connected to the hydrogen production power source, and the intermediate electrode plate of the electrolyzer is grounded.

[0026] The voltage detection circuit described above.

[0027] To achieve the above objectives, the present invention also proposes a control method for a hydrogen production power supply, wherein the hydrogen production power supply is connected to an electrolyzer, the intermediate electrode plate of the electrolyzer is grounded, and the control method includes:

[0028] Obtain the first voltage at the positive output terminal of the hydrogen production power supply and the second voltage at the negative output terminal of the hydrogen production power supply;

[0029] The fault status of the hydrogen production power supply is determined based on the first voltage or the second voltage.

[0030] When the fault condition is a ground fault, the hydrogen production power supply is controlled to stop supplying power.

[0031] Optionally, before determining the fault state based on the first voltage or the second voltage, the method further includes:

[0032] The differential calculation unit receives the output voltage fed back, which is calculated by the differential calculation unit based on the first voltage and the second voltage.

[0033] When the output voltage is greater than the threshold voltage, the step of determining the fault state based on the first voltage or the second voltage is performed, where the threshold voltage is the voltage at which the hydrogen production power supply operates normally.

[0034] In this invention, a first sampling circuit is connected to the positive output terminal of the hydrogen production power supply to obtain a first voltage at the positive output terminal; a second sampling circuit is connected to the negative output terminal of the hydrogen production power supply to obtain a second voltage at the negative output terminal; a detection unit is connected to the first and second sampling circuits respectively to determine the fault state based on the first or second voltage; thus, the existence of a grounding fault can be determined based on the voltage values ​​at the positive and negative output terminals of the hydrogen production power supply, and it can also determine whether the positive or negative output terminal is short-circuited. The structure is simple and easy to implement. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0036] Figure 1 This is a structural block diagram of one embodiment of the voltage detection circuit of the hydrogen production power supply of the present invention;

[0037] Figure 2 This is a structural block diagram of another embodiment of the voltage detection circuit of the hydrogen production power supply of the present invention;

[0038] Figure 3 This is a circuit diagram of another embodiment of the voltage detection circuit of the hydrogen production power supply of the present invention.

[0039] Figure 4 This is a flowchart illustrating one embodiment of the hydrogen production power supply control method of the present invention.

[0040] Explanation of icon numbers:

[0041] label name label name 10 Hydrogen production power supply 331 conditioning unit 20 Electrolytic cell 332 Digital-to-analog converter 30 Voltage detection circuit 333 controller 310 First sampling circuit 340 Differential computation unit 320 Second sampling circuit R1~R9 Resistors 1 to 9 330 Detection unit A1~A2 First and second operational amplifiers

[0042] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0043] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0045] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0046] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0047] Reference Figure 1 , Figure 1 This is a structural block diagram of one embodiment of the voltage detection circuit for a hydrogen production power supply according to the present invention. The present invention proposes an embodiment of the voltage detection circuit for a hydrogen production power supply.

[0048] like Figure 1 As shown, in this embodiment, the hydrogen production power supply 10 is connected to the electrolyzer 20, the intermediate plate of the electrolyzer 20 is grounded, and the voltage detection circuit 30 includes: a first sampling circuit 310, connected to the positive output terminal of the hydrogen production power supply 10, for obtaining a first voltage at the positive output terminal; a second sampling circuit 320, connected to the negative output terminal of the hydrogen production power supply 10, for obtaining a second voltage at the negative output terminal; and a detection unit 330, connected to the first sampling circuit 310 and the second sampling circuit 320 respectively, for determining the fault state of the hydrogen production power supply based on the first voltage or the second voltage.

[0049] Electrolyzer 20 can be an alkaline water electrolyzer or a PEM (Proton Exchange Membrane) electrolyzer. When the intermediate electrode plate is grounded, if a grounding fault occurs at the positive or negative output terminal of the hydrogen production power supply 10, the output terminal with the grounding fault will short-circuit with the intermediate electrode plate, and the voltage at the output terminal with the grounding fault will be close to 0.

[0050] The first sampling circuit 310 is used to detect a first voltage DC+, convert the first voltage DC+ into a first detection voltage, and transmit the first detection voltage to the detection unit 330. The second sampling circuit 320 is used to detect a second voltage DC-, convert the second voltage DC+ into a second detection voltage, and transmit the second detection voltage to the detection unit 330. The first sampling circuit 310 and the second sampling circuit 320 can adopt the same circuit structure, such as a voltage divider sampling unit or an inductive sampling unit.

[0051] The detection unit 330 is composed of components such as a microcontroller, so the voltage range it can receive is often low, such as below 5V. However, the output voltage of the hydrogen power supply 10 is often higher. Therefore, the first sampling circuit 310 and the second sampling circuit 320 need to have a voltage reduction function to prevent damage to the detection unit 330.

[0052] The detection unit 330 can determine the actual voltages of the first voltage DC+ and the second voltage DC- based on the received first and second detection voltages. The conversion ratio between the first detection voltage and the first voltage DC+, and the conversion ratio between the second detection voltage and the second voltage DC-, are mainly determined by the structures of the first sampling circuit 310 and the second sampling circuit 320.

[0053] In this embodiment, the fault states mainly include a non-fault state, a positive output terminal grounding fault, a negative output terminal grounding fault, and a positive and negative output terminal grounding fault. When the detection unit 330 detects that the received first detection voltage is zero, it determines that the first voltage DC+ is zero. If it simultaneously detects that the hydrogen power supply 10 is in an output state, it indicates a positive output terminal grounding fault. When the detection unit 330 detects that the received second detection voltage is zero, it determines that the second voltage DC- is zero. If it simultaneously detects that the hydrogen power supply 10 is in an output state, it indicates a negative output terminal grounding fault. When the detection unit 330 detects that both the received first and second detection voltages are zero, it determines that both the first voltage DC+ and the second voltage DC- are zero. If it simultaneously detects that the hydrogen power supply 10 is in an output state, it indicates a positive and negative output terminal grounding fault. When the detection unit 330 detects that neither the received first nor second detection voltage is zero, it determines that both the first voltage DC+ and the second voltage DC- are non-zero, indicating a non-fault state.

[0054] In this embodiment, a first sampling circuit 310 is connected to the positive output terminal of the hydrogen production power supply 10 to obtain the first voltage of the positive output terminal; a second sampling circuit 320 is connected to the negative output terminal of the hydrogen production power supply 10 to obtain the second voltage of the negative output terminal; a detection unit 330 is connected to the first sampling circuit 310 and the second sampling circuit 320 respectively to determine the fault state based on the first voltage or the second voltage; thus, based on the voltage values ​​of the positive and negative output terminals of the hydrogen production power supply 10, it can determine whether there is a grounding fault, and can also determine whether the positive output terminal is short-circuited or the negative output terminal is short-circuited. The structure is simple and easy to implement.

[0055] Reference Figure 2 , Figure 2 This is a structural block diagram of another embodiment of the voltage detection circuit for the hydrogen production power supply of the present invention. Based on the above embodiments, the present invention proposes another embodiment of the voltage detection circuit for the hydrogen production power supply.

[0056] In this embodiment, the voltage detection circuit 30 further includes a differential calculation unit 340, which is connected to the first sampling circuit 310 and the second sampling circuit 320 respectively, and is used to perform differential calculation on the first voltage and the second voltage to obtain a third voltage; the detection unit 330 is also connected to the differential calculation unit 340, and is used to determine the output voltage of the hydrogen production power supply 10 based on the third voltage.

[0057] While performing ground fault detection, the detection unit 330 can also detect the output voltage of the hydrogen production power supply 10, which can be used to characterize the operating status of the hydrogen production power supply 10. The detection unit 330 can also be connected to the hydrogen production power supply 10 to adjust its output voltage.

[0058] The detection unit 330 can determine the target output voltage of the hydrogen power supply 10 based on the user's input or the host computer's input, and then compare the output voltage determined based on the third voltage with the target output voltage to determine whether the operating state of the hydrogen power supply 10 is the required output state.

[0059] Simultaneously, the detection unit 330 can also control the switching of the output of the hydrogen production power supply 10. When the detection unit 330 determines, based on the first voltage or the second voltage, that a ground fault has occurred at the positive output terminal, a ground fault at the negative output terminal, or a ground fault at both positive and negative output terminals, it can control the hydrogen production power supply 10 to shut down its output.

[0060] In this embodiment, the detection unit 330 may include a conditioning unit 331, which is connected to the first sampling circuit 310 and the second sampling circuit 320 respectively, for conditioning the first voltage and the second voltage; a digital-to-analog conversion unit 332, which is connected to the conditioning unit 331, for converting the conditioned first voltage to obtain first voltage data, and for converting the conditioned second voltage to obtain second voltage data; and a controller 333, which is connected to the digital-to-analog conversion unit 332, for determining the fault state based on the first voltage data or the second voltage data.

[0061] The conditioning unit 331 can also be connected to the differential calculation unit 340 for conditioning the third voltage. The conditioning unit 331 is mainly used to stabilize or filter the first, second, and third voltages to ensure the accuracy of the acquired signals. The conditioning unit 331 can include regulated voltage, filtered voltage, etc., which are mature technologies and will not be described further in this embodiment.

[0062] Since the voltage signal is an analog signal, to facilitate analysis and processing by the controller 333, the analog-to-digital converter 332 can be used to convert the first, second, and third voltages conditioned by the conditioning unit 331 into digital signals, and then the obtained digital signals can be transmitted to the main controller 333. The main controller 333 can be connected to the hydrogen power supply 10 to control the switching of the hydrogen power supply 10 and to adjust the output voltage of the hydrogen power supply 10.

[0063] In this embodiment, the voltage detection circuit 30 can detect output ground faults and determine whether the output positive terminal is short-circuited or the negative terminal is short-circuited by sampling the hydrogen production power supply 10. At the same time, it can also meet the power supply output voltage sampling requirements, thus satisfying the requirements simultaneously.

[0064] Reference Figure 3 , Figure 3 This is a circuit diagram illustrating another embodiment of the voltage detection circuit for the hydrogen production power supply of the present invention. Based on the above embodiments, the present invention proposes yet another embodiment of the voltage detection circuit for the hydrogen production power supply.

[0065] In this embodiment, the first sampling circuit 310 includes: a first voltage divider unit and a second voltage divider unit connected in series, one end of the first voltage divider unit being connected to the positive output terminal of the hydrogen production power supply 10, and one end of the second voltage divider unit being grounded; and an operational amplifier unit, the input terminal of which is connected to the connection point of the first voltage divider unit and the second voltage divider unit, and the output terminal of which is connected to the detection unit 30.

[0066] The first and second voltage divider units connected in series can divide the output voltage of the hydrogen power supply 10. The ratio between the voltage connected to the operational amplifier unit and the positive output voltage of the hydrogen power supply 10 is related to the ratio between the first and second voltage divider units. The larger the multiple of the resistance of the first voltage divider unit compared to the resistance of the second voltage divider unit, the smaller the multiple of the voltage connected to the operational amplifier unit compared to the positive output voltage of the hydrogen power supply 10. The operational amplifier unit can further adjust the sampled voltage so that the detection unit 30 receives a voltage that is easy to identify.

[0067] Specifically, the first voltage divider unit includes a first resistor R1, and the second voltage divider unit includes a second resistor R2. By using a single resistor to form the voltage divider unit, the complexity of the circuit is reduced. Of course, each voltage divider unit can also be composed of multiple resistors connected in series or in parallel.

[0068] Specifically, the operational amplifier unit may include a first operational amplifier A1. The inverting input terminal of the first operational amplifier A1 is connected to the connection point through a third resistor R3. The inverting input terminal of the first operational amplifier A1 is connected to the output terminal of the first operational amplifier A1 through a fourth resistor R4. The non-inverting input terminal of the first operational amplifier A1 is grounded through a fifth resistor R5. The output terminal of the first operational amplifier A1 is connected to the detection unit 30.

[0069] In this embodiment, the second sampling circuit 320 can use the same circuit as the first sampling circuit 310, as detailed in the following reference. Figure 3 The operational amplifier unit can act as an inverting amplifier to facilitate subsequent calculations. The output voltage of the first operational amplifier A1 can be determined using the following formula:

[0070] Vp=-(R4 / R3)*(R2 / (R1+R2))*V DC+

[0071] Vn=-(R4 / R3)*(R2 / (R1+R2))*V DC-

[0072] Wherein, Vp is the output voltage of the first operational amplifier A1 in the first sampling circuit 310, and Vn is the output voltage of the first operational amplifier A1 in the second sampling circuit 320.

[0073] In this embodiment, the differential calculation unit 340 may include a second operational amplifier A2. The non-inverting input terminal of the second operational amplifier A2 is connected to the first sampling circuit 310 through a sixth resistor R6. The non-inverting input terminal of the second operational amplifier A2 is connected to the output terminal of the second operational amplifier A2 through a seventh resistor R7. The inverting input terminal of the second operational amplifier A2 is connected to the second sampling circuit 320 through an eighth resistor R8. The inverting input terminal of the second operational amplifier A2 is grounded through a ninth resistor R9. The output terminal of the second operational amplifier A2 is connected to the detection unit 30.

[0074] The differential calculation unit 340 is used to calculate the output voltage of the hydrogen production power supply 10. The output voltage of the second operational amplifier A2 can be calculated using the following formula:

[0075] Vpn=(R7 / R6)*(Vp-Vn)

[0076] Where Vpn is the output voltage of the second operational amplifier A2.

[0077] The conditioning unit 331 and the digital-to-analog conversion unit 332 process the power supplies Vp, Vn and Vpn in sequence, and then transmit the corresponding voltage data to the main controller 333. The main controller 333 determines whether there is a grounding fault based on the received voltage data and adjusts the output voltage of the hydrogen production power supply 10, as detailed above.

[0078] In this embodiment, a voltage detection circuit 30 with a simple circuit structure is provided. It can detect output-to-ground faults, determine whether the output positive terminal is short-circuited or the negative terminal is short-circuited, and also meet the power supply output voltage sampling requirements. It can meet the requirements at the same time and is easy to implement.

[0079] To achieve the above objectives, the present invention also proposes a hydrogen production system, comprising: a hydrogen production power supply, an electrolyzer, and a voltage detection circuit as described above; the electrolyzer is connected to the hydrogen production power supply, and the intermediate plate of the electrolyzer is grounded. The specific structure of the voltage detection circuit is as described in the above embodiments. Since this device can adopt the technical solutions of all the above embodiments, it at least possesses the beneficial effects brought about by the technical solutions of the above embodiments, and will not be elaborated further here.

[0080] Reference Figure 4 , Figure 4 This is a schematic flowchart illustrating one embodiment of the hydrogen production power supply control method of the present invention. To achieve the above objectives, based on the above embodiments, the present invention also proposes an embodiment of the hydrogen production power supply control method.

[0081] In this embodiment, the control method for the hydrogen production power source includes the following steps:

[0082] Step S10: Obtain the first voltage at the positive output terminal of the hydrogen production power supply and the second voltage at the negative output terminal of the hydrogen production power supply.

[0083] In this embodiment, the controller is the main actuator for controlling the hydrogen production power source, and it has functions such as data processing and data communication. Of course, the main actuator can also be other devices with the same functions, and this embodiment does not limit this.

[0084] The hydrogen production power supply is connected to the electrolyzer, and the intermediate electrode plate of the electrolyzer is grounded. The electrolyzer can be an alkaline water electrolyzer or a PEM (Proton Exchange Membrane) electrolyzer. With the intermediate electrode plate grounded, if a ground fault occurs at the positive or negative output terminal of the hydrogen production power supply 10, a short circuit will occur between the output terminal with the ground fault and the intermediate electrode plate, and the voltage at the output terminal with the ground fault will be close to 0.

[0085] The controller can be connected to the hydrogen production power supply via a sampling circuit. Based on the detection data fed back from the sampling circuit, the controller determines the first voltage at the positive output terminal and the second voltage at the negative output terminal of the hydrogen production power supply. The specific circuit structure of the sampling circuit can be found in the aforementioned embodiment.

[0086] Step S20: Determine the fault status of the hydrogen production power supply based on the first voltage or the second voltage.

[0087] The fault states mainly include a non-fault state, a positive output terminal grounding fault, a negative output terminal grounding fault, and a combined positive and negative output terminal grounding fault. A positive output terminal grounding fault occurs when the first voltage DC+ is detected as zero and the hydrogen power supply 10 is simultaneously in output mode. A negative output terminal grounding fault occurs when the second voltage DC- is detected as zero and the hydrogen power supply 10 is simultaneously in output mode. A combined positive and negative output terminal grounding fault occurs when both the first voltage DC+ and the second voltage DC- are detected as zero and the hydrogen power supply 10 is simultaneously in output mode. A non-fault state occurs when neither the first voltage DC+ nor the second voltage DC- is zero.

[0088] In this embodiment, the controller is also compatible with controlling the output voltage of the hydrogen production power supply. Therefore, the controller can also receive the output voltage fed back by the differential calculation unit, which is calculated by the differential calculation unit based on a first voltage and a second voltage. The controller can determine the output state of the hydrogen production power supply based on this output voltage. Specifically, when the output voltage is greater than a threshold voltage, the controller executes a step of determining a fault state based on the first voltage or the second voltage. The threshold voltage is the voltage at which the hydrogen production power supply operates normally.

[0089] When a ground fault occurs in the power supply line of the hydrogen production power source, the detected output voltage rises. Therefore, if the output voltage is less than the threshold voltage, it indicates that the hydrogen production power source will not experience a ground fault. Thus, the controller only needs to determine whether a ground fault exists when the output voltage is greater than the threshold voltage.

[0090] Step S30: When the fault condition is a ground fault, control the hydrogen production power supply to stop supplying power.

[0091] In the event of a grounding fault, the hydrogen production power supply must be shut down promptly to prevent damage to the electrolyzer. When the controller detects a grounding fault at the positive output terminal, a grounding fault at the negative output terminal, or a grounding fault at both positive and negative output terminals, it transmits a shutdown command to the hydrogen production power supply, which then responds to the shutdown command and stops outputting.

[0092] In this embodiment, the first voltage at the positive output terminal of the hydrogen production power supply and the second voltage at the negative output terminal of the hydrogen production power supply are obtained; the fault state is determined based on the first voltage or the second voltage; when the fault state is a ground fault, the hydrogen production power supply is controlled to stop supplying power; thus, the presence of a ground fault is determined based on the voltage values ​​at the positive and negative output terminals of the hydrogen production power supply, and it can also determine whether the positive output terminal is short-circuited or the negative output terminal is short-circuited, which is simple and easy to implement.

[0093] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A voltage detection circuit for a hydrogen production power supply, characterized in that, The hydrogen production power source is connected to the electrolyzer, the intermediate plate of the electrolyzer is grounded, and the voltage detection circuit includes: The first sampling circuit is connected to the positive output terminal of the hydrogen production power supply and is used to obtain the first voltage of the positive output terminal. The second sampling circuit is connected to the negative output terminal of the hydrogen production power supply and is used to obtain the second voltage of the negative output terminal. A differential calculation unit is connected to the first sampling circuit and the second sampling circuit respectively, and is used to perform differential calculation on the first voltage and the second voltage to obtain a third voltage; The detection unit is connected to the first sampling circuit, the second sampling circuit, and the differential calculation unit, respectively, and is used to determine the output voltage of the hydrogen production power supply based on the third voltage, and to determine the fault state of the hydrogen production power supply based on the output voltage of the hydrogen production power supply and the first voltage or the second voltage. The fault state includes positive output terminal grounding fault, negative output terminal grounding fault, and positive and negative output terminal grounding fault.

2. The voltage detection circuit as described in claim 1, characterized in that, The first sampling circuit includes: A first voltage divider unit and a second voltage divider unit are connected in series. One end of the first voltage divider unit is connected to the positive output terminal of the hydrogen production power supply, and one end of the second voltage divider unit is grounded. An operational amplifier unit is provided, wherein the input terminal of the operational amplifier unit is connected to the connection point of the first voltage divider unit and the second voltage divider unit, and the output terminal of the operational amplifier unit is connected to the detection unit.

3. The voltage detection circuit as described in claim 2, characterized in that, The first voltage divider unit includes a first resistor, and the second voltage divider unit includes a second resistor.

4. The voltage detection circuit as described in claim 2, characterized in that, The operational amplifier unit includes: The first operational amplifier has its inverting input connected to the connection point via a third resistor, its output connected to the first operational amplifier via a fourth resistor, its non-inverting input grounded via a fifth resistor, and its output connected to the detection unit.

5. The voltage detection circuit as described in claim 1, characterized in that, The difference calculation unit includes: The second operational amplifier has its non-inverting input connected to the first sampling circuit via a sixth resistor, its output connected to the second operational amplifier via a seventh resistor, its inverting input connected to the second sampling circuit via an eighth resistor, its inverting input grounded via a ninth resistor, and its output connected to the detection unit.

6. The voltage detection circuit as described in any one of claims 1-4, characterized in that, The detection unit includes: The conditioning unit is connected to the first sampling circuit and the second sampling circuit respectively, and is used to condition the first voltage and the second voltage; A digital-to-analog converter unit, connected to the conditioning unit, is used to convert the conditioned first voltage to obtain first voltage data, and to convert the conditioned second voltage to obtain second voltage data; The controller, connected to the digital-to-analog conversion unit, is used to determine the fault state based on the first voltage data or the second voltage data.

7. A hydrogen production system, characterized in that, The hydrogen production system includes: Hydrogen production power source; An electrolyzer is connected to the hydrogen production power source, and the intermediate electrode plate of the electrolyzer is grounded. The voltage detection circuit as described in any one of claims 1-6.

8. A method for controlling a hydrogen production power source, characterized in that, The hydrogen production power source is connected to the electrolyzer, the intermediate electrode plate of the electrolyzer is grounded, and the control method includes: Obtain the first voltage at the positive output terminal of the hydrogen production power supply and the second voltage at the negative output terminal of the hydrogen production power supply; The fault state of the hydrogen production power supply is determined based on the first voltage or the second voltage, and the fault state includes positive output terminal grounding fault, negative output terminal grounding fault, and positive and negative output terminal grounding fault. When the fault condition is a ground fault, the hydrogen production power supply is controlled to stop supplying power. Before determining the fault state based on the first voltage or the second voltage, the method further includes: The differential calculation unit receives the output voltage fed back, which is calculated by the differential calculation unit based on the first voltage and the second voltage. When the output voltage is greater than the threshold voltage, the step of determining the fault state based on the first voltage or the second voltage is performed, where the threshold voltage is the voltage at which the hydrogen production power supply operates normally.

Images