Hydrogen energy test power supply circuit, system and method integrated with EIS function

Abstract

The present application relates to the technical field of hydrogen energy, and particularly relates to a hydrogen energy test power supply circuit, system and method integrated with EIS function. The hydrogen energy test power supply circuit comprises an electrolytic cell interface, a control module, an EIS test module and an electrolysis power supply module. The EIS test module comprises an acquisition chip, a voltage acquisition circuit, a differential conditioning and amplification circuit, an analog switch switching circuit, a first AC / DC separation circuit, a second AC / DC separation circuit, a voltage-to-constant-current circuit and a calibration resistor. The control module is electrically connected to the electrolytic cell interface through the voltage acquisition circuit, and is electrically connected to the voltage-to-constant-current circuit and the differential conditioning and amplification circuit through the acquisition chip. The voltage-to-constant-current circuit is connected to the electrolytic cell interface through the calibration resistor. The first AC / DC separation circuit is connected in parallel across the calibration resistor. The differential conditioning and amplification circuit is electrically connected to the first AC / DC separation circuit and the second AC / DC separation circuit through the analog switch switching circuit, and the second AC / DC separation circuit is electrically connected to the electrolytic cell interface.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrogen energy, in particular to a hydrogen energy test power supply circuit, system and method integrated with EIS function. BACKGROUND

[0002] With the development of hydrogen energy technology, water electrolysis hydrogen production as a green and environmentally friendly method of hydrogen production, is attracting more and more attention. In the water electrolysis hydrogen production system, the hydrogen production power supply as a key electric energy conversion device, its performance directly affects the yield and quality of hydrogen. At present, the water electrolysis hydrogen production device on the market generally uses DSP digital power supply control constant current technology to drive the electrolytic cell.

[0003] However, in the existing water electrolysis hydrogen production device, the electrolysis power supply and the alternating current impedance test equipment are usually two independent devices, which need to be controlled independently by using two software respectively. This operation mode makes the operation process cumbersome and is not conducive to use. In addition, when the existing water electrolysis hydrogen production device performs alternating current impedance test, the electrolysis power supply uses a constant current source with digital control mode, which not only has switching noise, but also easily affects the test accuracy of electrochemical impedance spectroscopy (EIS); when performing EIS test, only a small alternating current disturbance signal can be applied, and a direct current bias current similar to a large electrolysis voltage cannot be provided, thereby limiting the application range of the test. SUMMARY

[0004] In order to solve at least one of the above problems existing in the prior art water electrolysis hydrogen production device, the present application provides a hydrogen energy test power supply circuit integrated with EIS function, which comprises an electrolytic cell interface, a control module, and an EIS test module and an electrolysis power supply module electrically connected with the control module.

[0005] The electrolysis power supply module comprises a current / voltage sampling unit and a power driving unit, and the control module is electrically connected with the electrolytic cell interface through the current / voltage sampling unit and the power driving unit respectively.

[0006] The EIS test module comprises an acquisition chip, a voltage acquisition circuit, a differential conditioning and amplification circuit, an analog switch switching circuit, a first AC / DC separation circuit, a second AC / DC separation circuit, a voltage-to-constant current circuit and a calibration resistor; the control module is electrically connected with the electrolytic cell interface through the voltage acquisition circuit; the control module is also electrically connected with the voltage-to-constant current circuit and the differential conditioning and amplification circuit through the acquisition chip; the voltage-to-constant current circuit is connected with the electrolytic cell interface through the calibration resistor; the first AC / DC separation circuit is connected in parallel across the calibration resistor; the differential amplification circuit is electrically connected with the first AC / DC separation circuit and the second AC / DC separation circuit through the analog switch switching circuit, and the second AC / DC separation circuit is electrically connected with the electrolytic cell interface.

[0007] When performing the EIS test, the acquisition chip applies a constant current signal superimposed by an adjustable small amplitude alternating current signal and a direct current bias signal to the electrolytic cell through the voltage-to-constant current circuit; at the same time, the alternating current response signal of the electrolytic cell is obtained through the second AC / DC separation circuit, the analog switch switching circuit and the differential conditioning and amplification circuit, and the alternating voltage signal of the calibration resistor is obtained through the calibration resistor, the first AC / DC separation circuit, the analog switch switching circuit and the differential conditioning and amplification circuit; the impedance parameters of the electrolytic cell are obtained by comparing the alternating current response signal of the electrolytic cell and the alternating voltage signal of the calibration resistor.

[0008] In some embodiments, the current / voltage sampling unit includes a current detection conditioning circuit, a current sampling resistor, a voltage detection conditioning circuit, a voltage detection circuit and a sampling chip; the control module is electrically connected with the current detection conditioning circuit and the voltage detection conditioning circuit through the sampling chip respectively; the current detection conditioning circuit is electrically connected with the current sampling resistor; the voltage detection conditioning circuit is electrically connected with the electrolytic cell interface;

[0009] The power driving unit includes a gate driving circuit and a MOS tube switching circuit; the control module is electrically connected with the current sampling resistor through the gate driving circuit and the MOS tube switching circuit in sequence; the current sampling resistor is electrically connected with the electrolytic cell interface.

[0010] In some embodiments, the voltage-to-constant current circuit includes a plurality of power transistors in parallel, an operational amplifier U7, an operational amplifier U8A, an operational amplifier U8B and a plurality of capacitors and resistors connected to the periphery of the operational amplifier U7, the operational amplifier U8A and the operational amplifier U8B;

[0011] The noninverting input terminal of the operational amplifier U7 is electrically connected with the acquisition chip; the output terminal of the operational amplifier U7 is electrically connected with the noninverting input terminal of the operational amplifier U8A; the inverting input terminal of the operational amplifier U8A is electrically connected with the output terminal of the operational amplifier U8B; the output terminal of the operational amplifier U8A is electrically connected with the gate of the power transistor; the noninverting input terminal and the inverting input terminal of the operational amplifier U8B are electrically connected with the source of the power transistor; the drain of the power transistor is electrically connected with the calibration resistor.

[0012] In some embodiments, the first AC-DC separation circuit includes a capacitor C31, a capacitor C33, a resistor R39, a resistor R41, a resistor R38, a resistor R42, and a low-pass filter LPF0; the first ends of the capacitor C31 and the capacitor C33 are connected in parallel across the calibration resistor; the second end of the capacitor C31 is electrically connected with the resistor R39 and the resistor R38 respectively; the resistor R39 is electrically connected with the low-pass filter LPF0; the second end of the capacitor C33 is electrically connected with the resistor R41 and the resistor R42 respectively; the resistor R41 is electrically connected with the low-pass filter LPF0; the resistor R38 and the resistor R42 are electrically connected with the analog switch switching circuit;

[0013] The second AC-DC separation circuit includes a capacitor C28, a capacitor C30, a resistor R35, a resistor R36, a resistor R10, a resistor R37, and a low-pass filter LPF0; the first ends of the capacitor C28 and the capacitor C30 are electrically connected with the electrolytic tank interface respectively; the second end of the capacitor C28 is electrically connected with the resistor R35 and the resistor R10 respectively; the resistor R35 is electrically connected with the low-pass filter LPF0; the second end of the capacitor C30 is electrically connected with the resistor R36 and the resistor R37 respectively; the resistor R36 is electrically connected with the low-pass filter LPF0; the resistor R10 and the resistor R42 are electrically connected with the analog switch switching circuit.

[0014] In some embodiments, the electrolytic tank interface includes a positive power line, a negative power line, a positive voltage detection line, and a negative voltage detection line; the hydrogen energy test power supply circuit further includes a relay K1, a relay K2, a relay K3, and a relay K4; the relays K1, K2, K3, and K4 each have a first set of switch contacts and a second set of switch contacts.

[0015] The first set of switch contacts of the relay K1 is connected with the positive power line and a current sampling resistor respectively; the second set of switch contacts of the relay K1 is connected with the negative power line and the current sampling resistor respectively; the first set of switch contacts of the relay K2 is connected with the positive voltage detection line and a voltage detection circuit respectively; the second set of switch contacts of the relay K2 is connected with the negative voltage detection line and the voltage detection circuit respectively;

[0016] The first set of switch contacts of the relay K3 is connected with the positive power line and a power supply respectively; the second set of switch contacts of the relay K3 is connected with the positive voltage detection line and the second AC-DC separation circuit respectively; the first set of switch contacts of the relay K4 is connected with the negative voltage detection line and the second AC-DC separation circuit respectively; the second set of switch contacts of the relay K4 is connected with the negative power line and the calibration resistor respectively;

[0017] The relay K1, the relay K2, the relay K3 and the relay K4 are controlled to switch to the EIS test module to perform EIS test or switch to the electrolysis power supply module to perform polarization test.

[0018] In some embodiments, the differential conditioning amplifier circuit comprises an operational amplifier U10A, an operational amplifier U10B, an operational amplifier U10C, an operational amplifier U10D, a resistor R68, a resistor R69, a resistor R72, a resistor R71, a resistor R74, a resistor R75, a capacitor C54, a capacitor C56, a resistor R70, a resistor R67, a resistor R73, a resistor R76.

[0019] The non-inverting input terminals of the operational amplifier U10A and the operational amplifier U10C are electrically connected to the analog switch switching circuit; the inverting input terminals of the operational amplifier U10A and the operational amplifier U10C are electrically connected to each other through the resistor R71; the output terminal of the operational amplifier U10A is electrically connected to the inverting input terminal of the operational amplifier U10A through the resistor R69 in one way and connected to the input power supply through the capacitor C54 and the resistor R68 in another way; the input terminal of the operational amplifier U10C is electrically connected to the inverting input terminal of the operational amplifier U10C through the resistor R74 in one way and connected to the input power supply through the capacitor C56 and the resistor R75 in another way.

[0020] The inverting input terminals of the operational amplifier U10B and the operational amplifier U10D are electrically connected to each other through the resistor R72; the non-inverting input terminal of the operational amplifier U10B is connected to the output terminal of the operational amplifier U10A through the capacitor C54; the non-inverting input terminal of the operational amplifier U10D is electrically connected to the output terminal of the operational amplifier U10C through the capacitor C56; the output terminal of the operational amplifier U10B is electrically connected to the inverting input terminal of the operational amplifier U10B through the resistor R70 in one way and electrically connected to the acquisition chip through the resistor R67 in another way; the output terminal of the operational amplifier U10D is electrically connected to the inverting input terminal of the operational amplifier U10D through the resistor R73 in one way and electrically connected to the acquisition chip through the resistor R76 in another way.

[0021] In some embodiments, the control module comprises a first control chip and a second control chip, the first control chip is electrically connected to the electrolysis power supply module, and the second control chip is electrically connected to the EIS test module.

[0022] In some embodiments, the model of the acquisition chip is AD5941 or AD5940.

[0023] The embodiment of the present application also provides a hydrogen energy test system, which adopts the hydrogen energy test power supply circuit integrated with the EIS function as described in any of the above embodiments.

[0024] The embodiment of the present application also provides a test method of the hydrogen energy test power supply circuit, which adopts the hydrogen energy test power supply circuit integrated with the EIS function as described in any of the embodiments or the hydrogen energy test system as described in the above embodiment, and further comprises the following test method.

[0025] When the current of the electrolytic tank is less than or equal to the preset normal working current of the electrolytic tank, the electrolysis power supply module does not work, and the EIS test module works to perform the EIS test; when the EIS test is performed, the EIS test module applies a constant current signal superimposed by a small amplitude AC signal and a DC bias signal to the electrolytic tank, and obtains the impedance parameters of the electrolytic tank by comparing the AC response signal of the electrolytic tank with the AC voltage signal of the calibration resistor;

[0026] When the current of the electrolytic tank is greater than the preset normal working current of the electrolytic tank, the EIS test module does not work, and the electrolysis power supply module works to perform the polarization test; when the polarization test is performed, the power driving unit applies a predetermined current transition or voltage transition to the electrolytic tank; at the same time of applying the current transition or voltage transition, the current / voltage sampling unit collects the voltage and current of the electrolytic tank to obtain the polarization behavior of the electrolytic tank.

[0027] Based on the above, compared with the prior art, the hydrogen energy test power supply circuit integrated with the EIS function provided by the present application integrates the polarization test and EIS test functions by the circuit design of each electrolysis power supply module and EIS test module, has the advantages of small size, simple structure, small volume, low cost, no switch noise, and no need for complex independent equipment; in addition, the EIS test module can not only provide a small amplitude AC disturbance signal but also provide a large amplitude DC bias current, which can effectively improve the accuracy and diversity of the EIS test.

[0028] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application can be realized and achieved by the structure particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0029] 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Unless otherwise specified, the positional relationships shown in the drawings in the following description are based on the direction in which the components are drawn in the figure.

[0030] Figure 1 A circuit module block diagram of a hydrogen energy testing power supply circuit with integrated EIS function provided in an embodiment of the present invention;

[0031] Figure 2 A circuit block diagram of a hydrogen energy testing power supply circuit with integrated EIS function provided in another embodiment of the present invention;

[0032] Figure 3 The circuit schematic of the current / voltage sampling unit;

[0033] Figure 4 This is the circuit schematic of the power drive unit;

[0034] Figure 5 The circuit schematic of the data acquisition chip;

[0035] Figure 6 The circuit diagram shows the connection of the voltage-to-constant-current circuit, the first AC / DC separation circuit, the second AC separation circuit, and the calibration resistor.

[0036] Figure 7 This is the circuit schematic of a differential conditioning amplifier circuit. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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 some embodiments of the present invention, not all embodiments. The technical features designed in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0038] In the description of the present application, it should be noted that all the terms (including technical terms and scientific terms) used in the present application have the same meaning as that generally understood by the ordinary skilled person in the field to which the present application belongs, and cannot be understood as a limitation on the present application; it should be further understood that the terms used in the present application should be understood as having the same meaning as the terms in the context of the present application and the related field, and should not be understood in an idealized or overly formal sense, unless otherwise defined in the present application.

[0039] Currently, the hydrogen production power of existing water electrolysis hydrogen production energy devices generally uses DSP (Digital Signal Processor) digital power supply for constant current control to ensure the stability and efficiency of the electrolysis process. However, there are the following problems in actual application: 1. The existing electrolysis power supply and AC impedance test equipment are usually two independent devices, each of which needs independent software for control. This separated control system leads to complex operation, inconvenient use, and increases the burden of the operator. 2. When performing AC impedance test, the switching action of the constant current source controlled by the digital control method of the electrolysis power supply will generate noise. This switching noise will interfere with the accuracy of the electrochemical impedance spectroscopy (EIS) test, thereby affecting the analysis and understanding of the dynamics of the electrolysis process. 3. When using the AC impedance test equipment to perform EIS test, a small AC disturbance signal, such as 100 mA, is usually applied. This small AC signal cannot provide a larger DC bias current similar to the actual electrolysis required, limiting the practicality and relevance of the test. 4. The existing electrolysis power supply and electrochemical workstation equipment are large in size, difficult to realize miniaturization and integration. This not only limits the portability of the equipment, but also increases the manufacturing cost and maintenance cost of the equipment, making the overall system expensive.

[0040] To effectively solve at least one of the above problems, the present application provides a hydrogen energy test power supply circuit, system and method integrated with EIS function, which will be described in detail below according to specific embodiments and drawings.

[0041] Embodiment one

[0042] Please refer to Figure 1 The embodiment of the present application provides a hydrogen energy test power supply circuit integrated with EIS function, which at least includes an electrolytic cell interface, a control module, and an EIS test module and an electrolysis power supply module electrically connected with the control module.

[0043] The control module can comprise an MCU or other processor. Preferably, the control module is provided with a communication interface for communication connection with the upper computer, for transmission of corresponding control instructions and data information. In the embodiment, the control module preferably comprises a first control chip and a second control chip, the first control chip being electrically connected with the electrolysis power module, and the second control chip being electrically connected with the EIS test module. The first control chip is used for controlling the electrolysis power module to work, and the second control chip is used for controlling the EIS test module to work. The first control chip and the second control chip can be independent or integrated together, and the first control chip and the second control chip can also be provided with related peripheral circuits, which can be designed according to actual needs, and are not limited herein.

[0044] The electrolysis power module comprises a current / voltage sampling unit and a power driving unit, and the control module is electrically connected with the electrolytic tank interface through the current / voltage sampling unit and the power driving unit respectively.

[0045] In specific implementation, the current / voltage sampling unit is used for collecting current and voltage of the electrolytic tank and feeding back to the control module, which can be realized by a sampling resistor and a resistor voltage divider circuit; the power driving unit is used for controlling the switching of a power switching device, and a PWM (pulse width modulation) signal generated by a digital control core is power-amplified through a related driving circuit to drive the power switching device; the specific circuit connection of the current / voltage sampling unit and the power driving unit is a conventional design, which is not limited herein.

[0046] Please refer to Figure 2 In the embodiment, the current / voltage sampling unit preferably comprises a current detection conditioning circuit, a current sampling resistor, a voltage detection conditioning circuit, a voltage detection circuit and a sampling chip; the control module is electrically connected with the current detection conditioning circuit and the voltage detection conditioning circuit through the sampling chip; the current detection conditioning circuit is electrically connected with the current sampling resistor; and the voltage detection conditioning circuit is electrically connected with the electrolytic tank interface.

[0047] Specifically as Figure 4As shown, the current detection conditioning circuit includes an operational amplifier U1, an operational amplifier U4 and a plurality of capacitors and resistors electrically connected with the operational amplifier U1 and the operational amplifier U4; wherein the two-stage operational amplifier is used for accurately amplifying the current signal flowing through the current sampling resistor, and transmitting the amplified current signal to the sampling chip, and transmitting the current signal converted by the sampling chip to the control module, so that the control module can accurately obtain the current of the electrolytic cell. The voltage conditioning and amplification circuit includes an operational amplifier U3B and a plurality of capacitors and resistors electrically connected with the operational amplifier U3B; similarly, the operational amplifier is used for amplifying and conditioning the voltage signal, and transmitting the voltage signal to the sampling chip, and transmitting the voltage signal converted by the sampling chip to the control module, so that the control module can accurately obtain the voltage of the electrolytic cell.

[0048] Please continue to refer to Figure 2 In the embodiment, the power driving unit preferably includes a gate driving circuit and a MOS tube switching circuit; the control module is electrically connected with the current sampling resistor through the gate driving circuit and the MOS tube switching circuit in sequence; and the current sampling resistor is electrically connected with the electrolytic cell interface.

[0049] Please refer to Figure 4 The gate driving circuit mainly includes a driving chip U2 and peripheral circuits, wherein the driving chip U2 is used for generating a signal suitable for driving the MOS tube in the MOS tube switching circuit according to the control signal generated by the control module to control the switching of the MOS tube. The MOS tube switching circuit includes one or more MOS tubes to control the current flowing to the electrolytic cell. In the embodiment, the MOS tube switching circuit includes MOS tubes Q1, Q2, Q3 and Q4. In addition, a plurality of capacitors are connected in parallel at the input side and the output side of the MOS tube switching circuit to filter and provide stable voltage for the electrolytic cell.

[0050] Further, please continue to refer to Figure 4 The electrolysis power module further includes a temperature detection circuit, wherein the sensor of the temperature detection circuit is arranged near the MOS tube to monitor the temperature of the MOS tube in real time, so as to prevent the MOS tube from being damaged due to overheating.

[0051] Please refer to Figure 2The EIS test module includes a collection chip, a voltage collection circuit, a differential conditioning amplification circuit, an analog switch switching circuit, a first AC / DC separation circuit, a second AC / DC separation circuit, a voltage-to-constant current circuit and a calibration resistor. The control module is electrically connected to the electrolytic tank through the voltage collection circuit. The control module is also electrically connected to the voltage-to-constant current circuit and the differential conditioning amplification circuit through the collection chip. The voltage-to-constant current circuit is connected to the electrolytic tank through the calibration resistor. The first AC / DC separation circuit is connected in parallel across the calibration resistor. The differential amplification circuit is electrically connected to the first AC / DC separation circuit and the second AC / DC separation circuit through the analog switch switching circuit. The second AC / DC separation circuit is electrically connected to the electrolytic tank.

[0052] In specific implementation, the collection chip is used to collect the response signal of the electrolytic tank to obtain the impedance spectrum data of the EIS test, and is also used to output an AC voltage signal with adjustable DC bias amplitude and superimposed amplitude / frequency, and apply the AC voltage signal on the electrolytic tank through the voltage-to-constant current circuit. The preferred model of the collection chip is AD5941 or AD5940. Taking AD5941 as an example, the chip is internally integrated with DAC, ADC and digital waveform generator, and complex impedance measurement (DFT) engine, so that the real part and the imaginary part of the impedance can be calculated in the chip, thereby obtaining the impedance spectrum data effectively. The circuit diagram of the collection chip with the model AD5941 and the related peripheral circuit can be referred to Figure 5 .

[0053] The input end of the voltage-to-constant current circuit is electrically connected to the collection chip, and the output end is electrically connected to the electrolytic tank through the calibration resistor, so as to convert the AC voltage signal output by the collection chip into a constant current signal, and apply the constant current signal to the electrolytic tank through the calibration resistor, thereby effectively ensuring that the current applied to the electrolytic tank and the calibration resistor is constant. That is, since the impedance of the electrolytic tank is variable, the use of a constant current source can ensure the stability of the excitation signal, thereby obtaining more accurate impedance measurement results. In addition, the current value of the constant current signal can be adjusted by adjusting the AC voltage signal output by the collection chip, and the electrochemical impedance spectrum of the electrolytic tank can be obtained by adjusting and analyzing the AC current amplitude and phase at different frequencies.

[0054] Further, the DC bias amplitude adjustable and superimposed AC voltage signal with adjustable amplitude / frequency output by the acquisition chip is converted into a constant current signal by the voltage constant current circuit and applied to the electrolytic cell through the calibration resistor. The electrolytic cell generates a response signal in response to the applied constant current signal. Since the electrochemical impedance of the electrolytic cell changes with the frequency of the applied signal, the amplitude and phase of the AC current of the response signal also change with the frequency. Therefore, when performing EIS testing, since the constant current signal applied to the electrolytic cell contains AC and DC components, the AC component needs to be retained while the DC component is removed when extracting the constant current signal applied to the electrolytic cell and the response signal of the electrolytic cell to AC excitation, in order to effectively complete the subsequent impedance analysis.

[0055] Based on this, the first AC / DC separation circuit and the second AC / DC separation circuit are designed in the embodiment. The first AC / DC separation circuit is electrically connected with the electrolytic cell interface, and is used to separate the AC component (i.e. the AC response signal) in the response signal of the electrolytic cell to AC excitation, for subsequent impedance analysis. The second AC / DC separation circuit is connected in parallel across the calibration resistor, and is used to separate the AC component (i.e. the AC voltage signal) in the constant current signal flowing through the calibration resistor, also for subsequent impedance analysis. The first AC / DC separation circuit and the second AC / DC separation circuit both include a low-pass filter to allow low-frequency AC signals to pass through and prevent high-frequency DC signals to pass through. The specific circuit connection mode can be designed according to actual needs, which is not limited by the embodiment.

[0056] The analog switch switching circuit is electrically connected with the first AC / DC separation circuit and the second AC / DC separation circuit, respectively, to switch different circuit paths according to the actual EIS testing needs. Specifically, the analog switch switching circuit is used to quickly switch between the electrolytic cell and the standard resistor to measure the AC response signal of the electrolytic cell and the AC voltage signal of the calibration resistor in different test stages, respectively, so as to facilitate the elimination of DC offset and gain error in the measurement system. Preferably, the analog switch switching circuit can use a transistor or an integrated analog switch as a switch.

[0057] The AC response signal and the constant current signal are small due to the AC disturbance, and the AC response signal and the AC voltage signal obtained after AC-DC separation are smaller, so the differential amplification is needed before entering the acquisition chip. Therefore, in the embodiment, the input end of the differential conditioning amplification circuit is connected with the first AC-DC separation circuit and the second AC-DC separation circuit through the analog switch switching circuit, and the output end is connected with the acquisition chip, which not only amplifies the small AC response signal and the AC voltage signal collected by the electrolytic cell and the calibration resistor to facilitate AD conversion and processing by the acquisition chip, but also effectively suppresses common mode interference and improves the quality of the signal. In the embodiment, the differential conditioning amplification circuit is preferably composed of multiple operational amplifiers to realize gain adjustment and filtering processing, etc. by cooperating with several resistors and capacitors, and the specific settings are made according to the actual needs.

[0058] The voltage acquisition circuit is used to monitor the voltage change between the electrodes of the electrolytic cell in real time. The control module is connected with the electrolytic cell interface through the voltage acquisition circuit. The specific voltage acquisition circuit can use appropriate chips and circuits to collect the voltage signal of the electrolytic cell in real time. The specific circuit is a conventional design, which will not be described here.

[0059] In summary, when performing EIS test, the acquisition chip applies a small amplitude AC signal and a DC bias signal superimposed constant current signal to the electrolytic cell through the voltage-to-constant current circuit. The superposition of the DC bias signal not only reduces the double-layer effect of the electrode, stabilizes and controls the electrode potential, but also makes the measurement result closer to the actual working state, improves the measurement accuracy, and simulates the actual operating conditions of the system cabinet, which helps to study the mixed effect of AC and DC in the system, and provides more in-depth research for EIS test analysis.

[0060] At the same time, when performing EIS test, the acquisition chip obtains the AC response signal of the electrolytic cell through the second AC-DC separation circuit, the analog switch switching circuit and the differential conditioning amplification circuit, and obtains the AC voltage signal of the calibration resistor through the calibration resistor, the first AC-DC separation circuit, the analog switch switching circuit and the differential conditioning amplification circuit; the impedance parameters of the electrolytic cell are obtained by comparing the AC response signal of the electrolytic cell and the AC voltage signal of the calibration resistor. Specifically, since the current flowing through the electrolytic cell and the calibration resistor is consistent, the impedance parameters of the electrolytic cell can be obtained by collecting and comparing the AC response signal of the electrolytic cell and the AC voltage signal of the calibration resistor; the specific formula is Z load =Z RCAL *U load / U RACL . In the formula, Z load is the impedance parameter of the electrolytic cell, Z RCAL is the impedance parameter of the calibration resistor, and Uload U is an AC response signal of the electrolytic cell RACL U is an AC voltage signal of the calibration resistor.

[0061] It should be noted that the above-mentioned various modules can be designed according to specific functions using existing conventional circuits or computer programs, which will not be described here.

[0062] To effectively explain the role and effect of the EIS test module provided by the embodiments of the present application, the following will be described in detail with reference to the specific circuit connection schematic diagram of the EIS test module as an example.

[0063] Please refer to Figure 6 The voltage-to-constant current circuit includes a plurality of power transistors in parallel, an operational amplifier U7, an operational amplifier U8A, an operational amplifier U8B, and a plurality of capacitors and resistors connected to the periphery of the operational amplifier U7, the operational amplifier U8A, and the operational amplifier U8B.

[0064] The non-inverting input terminal of the operational amplifier U7 is electrically connected to the acquisition chip; the output terminal of the operational amplifier U7 is electrically connected to the non-inverting input terminal of the operational amplifier U8A; the inverting input terminal of the operational amplifier U8A is electrically connected to the output terminal of the operational amplifier U8B; the output terminal of the operational amplifier U8A is electrically connected to the gate of the power transistor; the non-inverting input terminal and the inverting input terminal of the operational amplifier U8B are electrically connected to the source of the power transistor; and the drain of the power transistor is electrically connected to the calibration resistor.

[0065] The power transistor is used to realize the conversion of voltage to constant current, has a high current driving capability, and can meet the current demand of the electrolytic cell in the EIS test. Since the main power consumption of the voltage-to-constant current circuit is on the power transistor, the embodiment can effectively reduce the heat generation of a single power transistor by connecting multiple power transistors in parallel. The number of power transistors is not limited to four, i.e., the power transistor Q5, the power transistor Q6, the power transistor Q7, and the power transistor Q8 shown in the drawing, and can be set according to actual needs.

[0066] The operational amplifier U7, the operational amplifier U8A, and the operational amplifier U8B constitute the control part of the voltage-to-constant current circuit, can adjust and stabilize the output current, and the capacitors and resistors connected to the periphery of the operational amplifier U7, the operational amplifier U8A, and the operational amplifier U8B are used to realize functions such as filtering, feedback, and biasing.

[0067] Through the above-mentioned circuit design of the voltage-to-constant current circuit, it can be effectively ensured that the current applied to the electrolytic cell and the calibration resistor is constant.

[0068] Please continue to refer toFigure 6 The first AC-DC separation circuit comprises a capacitor C31, a capacitor C33, a resistor R39, a resistor R41, a resistor R38, a resistor R42, and a low-pass filter LPF0; the first ends of the capacitor C31 and the capacitor C33 are connected in parallel across the calibration resistor; the second end of the capacitor C31 is electrically connected with the resistor R39 and the resistor R38; the resistor R39 is electrically connected with the low-pass filter LPF0; the second end of the capacitor C33 is electrically connected with the resistor R41 and the resistor R42; the resistor R41 is electrically connected with the low-pass filter LPF0; the resistor R38 and the resistor R42 are electrically connected with the analog switch switching circuit; the second AC-DC separation circuit comprises a capacitor C28, a capacitor C30, a resistor R35, a resistor R36, a resistor R10, a resistor R37, and a low-pass filter LPF0; the first ends of the capacitor C28 and the capacitor C30 are electrically connected with the electrolytic tank interface; the second end of the capacitor C28 is electrically connected with the resistor R35 and the resistor R10; the resistor R35 is electrically connected with the low-pass filter LPF0; the second end of the capacitor C30 is electrically connected with the resistor R36 and the resistor R37; the resistor R36 is electrically connected with the low-pass filter LPF0; the resistor R10 and the resistor R42 are electrically connected with the analog switch switching circuit.

[0069] Please refer to Figure 7 The differential conditioning amplification circuit comprises an operational amplifier U10A, an operational amplifier U10B, an operational amplifier U10C, an operational amplifier U10D, a resistor R68, a resistor R69, a resistor R72, a resistor R71, a resistor R74, a resistor R75, a capacitor C54, a capacitor C56, a resistor R70, a resistor R67, a resistor R73, and a resistor R76.

[0070] The non-inverting input end of the operational amplifier U10A and the non-inverting input end of the operational amplifier U10C are electrically connected to each other through the resistor R71; one way of the output end of the operational amplifier U10A is electrically connected to the non-inverting input end of the operational amplifier U10A through the resistor R69, and the other way is connected to the input power supply through the capacitor C54 and the resistor R68; one way of the input end of the operational amplifier U10C is electrically connected to the non-inverting input end of the operational amplifier U10C through the resistor R74, and the other way is connected to the input power supply through the capacitor C56 and the resistor R75. The non-inverting input end of the operational amplifier U10B and the non-inverting input end of the operational amplifier U10D are electrically connected to each other through the resistor R72; the non-inverting input end of the operational amplifier U10B is connected to the output end of the operational amplifier U10A through the capacitor C54; the non-inverting input end of the operational amplifier U10D is electrically connected to the output end of the operational amplifier U10C through the capacitor C56; one way of the output end of the operational amplifier U10B is electrically connected to the non-inverting input end of the operational amplifier U10B through the resistor R70, and the other way is electrically connected to the acquisition chip through the resistor R67; one way of the output end of the operational amplifier U10D is electrically connected to the non-inverting input end of the operational amplifier U10D through the resistor R73, and the other way is electrically connected to the acquisition chip through the resistor R76.

[0071] By the effective design of the operational amplifier and the resistors, the differential amplification of the input signal can be realized, and the amplification multiple can be adjusted by adjusting the resistance values of the resistors R69, R71, R74, R70, R73 and R72.

[0072] Further, in order to effectively control the switching of the polarization test and the EIS test of the electrolytic cell, the embodiment preferably adopts multiple groups of relays to realize. Specifically, referring to Figure 2 , Figure 3 , Figure 6 , the electrolytic cell interface includes a positive power line, a negative power line, a positive voltage detection line and a negative voltage detection line; the hydrogen energy test power supply circuit further includes relays K1, K2, K3 and K4; the relays K1, K2, K3 and K4 each have a first group of switch contacts and a second group of switch contacts. It should be noted that Figure 2 The electrolytic cell interface is provided with switches SW1, SW2, SW3 and SW4, and the switches are only a simplified schematic diagram. In actual Figure 3 , Figure 6 application, the corresponding relays are K1, K2, K3 and K4.

[0073] The first group of switch contacts of the relay K1 are connected to the positive power line and the current sampling resistor respectively; the second group of switch contacts of the relay K1 are connected to the negative power line and the current sampling resistor respectively; the first group of switch contacts of the relay K2 are connected to the positive voltage detection line and the voltage detection circuit respectively; the second group of switch contacts of the relay K2 are connected to the negative voltage detection line and the voltage detection circuit respectively; the first group of switch contacts of the relay K3 are connected to the positive power line and the power supply respectively; the second group of switch contacts of the relay K3 are connected to the positive voltage detection line and the second AC-DC separation circuit respectively; the first group of switch contacts of the relay K4 are connected to the negative voltage detection line and the second AC-DC separation circuit respectively; and the second group of switch contacts of the relay K4 are connected to the negative power line and the calibration resistor respectively.

[0074] By controlling the relays K1, K2, K3 and K4 as described above, the EIS test module can be switched to work for EIS test or the electrolysis power supply module can be switched to work for polarization test; specifically, when the relays K1 and K2 are closed and the relays K3 and K4 are open, the EIS test module is not connected to the electrolysis tank, and the electrolysis power supply module is connected to the electrolysis tank for polarization test. Conversely, when the relays K1 and K2 are open and the relays K3 and K4 are closed, the EIS test module is connected to the electrolysis tank for EIS test, and the electrolysis power supply module is not connected to the electrolysis tank. In addition, by switching the relays, the electrolysis power supply does not work when the EIS test is performed, so there is no switching noise due to the fact that the electrolysis power supply is a digital control constant current source, and the accuracy of the EIS test is not affected.

[0075] It should be noted that those skilled in the art can change the connection of the corresponding circuit according to the functions and connection relationships of the above-mentioned circuits, which all fall within the protection scope of the present application.

[0076] Embodiment two

[0077] The present application also provides a hydrogen energy test system adopting the hydrogen energy test power supply circuit integrated with the EIS function as described in any of the above embodiments. The hydrogen energy test system integrates the electrolysis power supply and the EIS test scheme in a small size, has a simple structure, low cost and can be effectively applied to the test of water electrolysis process devices. The specific circuit design of the hydrogen energy test power supply circuit integrated with the EIS function can be referred to the foregoing description, which will not be described here again.

[0078] Preferably, the hydrogen energy test system further comprises a host computer (such as a PC) which is connected to the hydrogen energy test power supply circuit through wired or wireless communication for transmitting corresponding data information. For example, USB is used to realize the communication connection.

[0079] Embodiment three

[0080] The embodiment of the present application also provides a test method for the hydrogen energy test power supply circuit, which adopts the integrated EIS function hydrogen energy test power supply circuit or the hydrogen energy test system as described in the above embodiments. The specific structure, circuit design and function of the integrated EIS function hydrogen energy test power supply circuit and the hydrogen energy test system can be referred to the description of the embodiments one and two, and will not be repeated here.

[0081] The test method for the hydrogen energy test power supply circuit comprises the following steps:

[0082] When the current of the electrolytic tank is less than or equal to the preset normal working current of the electrolytic tank, the electrolysis power module does not work, and the EIS test module works to perform EIS test; during the EIS test, the EIS test module applies a small amplitude alternating current signal and a direct current bias signal to the electrolytic tank, and obtains the impedance parameters of the electrolytic tank by comparing the alternating current response signal of the electrolytic tank with the alternating voltage signal of the calibration resistor;

[0083] When the current of the electrolytic tank is greater than the preset normal working current of the electrolytic tank, the EIS test module does not work, and the electrolysis power module works to perform polarization test; during the polarization test, the power driving unit applies a predetermined current transition or voltage transition to the electrolytic tank; at the same time of applying the current transition or voltage transition, the current / voltage sampling unit collects the voltage and current of the electrolytic tank to obtain the polarization behavior of the electrolytic tank.

[0084] Through the above setting, switching can be performed according to different test state requirements. When a small amplitude alternating current disturbance is applied during EIS test, a certain direct current bias signal can be applied, and the electrolysis power module does not work; when a larger current is required for polarization test, only the electrolysis power module works, and the EIS test function is not required, and the EIS test module does not work. Taking the normal working current of the electrolytic tank as an example, which is usually 4A (working condition), when the current is less than or equal to 4A, the EIS test module can output a transverse current signal superimposed with a 4A direct current bias and a small amplitude alternating current signal; when the current is greater than 4A, the EIS test module does not work, and only the electrolysis power module works.

[0085] In summary, compared with the prior art, the integrated EIS function hydrogen energy test power supply circuit, system and method provided by the present application have the following advantages:

[0086] I. Through the circuit design of the electrolysis power module and the EIS test module, the polarization test and EIS test functions can be effectively realized, independent equipment is not required for independent control test, and the electrolytic tank detection under various working conditions can be effectively applied;

[0087] Secondly, the polarization test or EIS test can be switched independently according to different current states, and the operation is simple. When the EIS test is performed, there is no switching noise due to the digital control constant current source of the electrolytic power supply, and the accuracy of the EIS test is not affected.

[0088] Thirdly, the EIS test module can not only apply a small AC disturbance signal but also provide a larger DC bias current, and can effectively and accurately perform the EIS test.

[0089] Fourthly, the structure is simple, the volume is small, the cost is low, and the test function of miniaturization and integration is effectively realized.

[0090] In addition, those skilled in the art should understand that although there are many problems in the prior art, each embodiment or technical solution of the present application can only be improved in one or several aspects, and it is not necessary to solve all the technical problems listed in the prior art or background art at the same time. Those skilled in the art should understand that the content not mentioned in a claim should not be regarded as a limitation of the claim.

[0091] Although terms such as electrolytic tank interface, control module, EIS test module, electrolytic power supply module, etc. are used more in this paper, the possibility of using other terms is not excluded. The use of these terms is only to facilitate the description and explanation of the essence of the present application; any additional limitation is contrary to the spirit of the present application; the terms "first", "second", etc. (if any) in the specification and claims of the embodiments of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not have to describe a specific order or sequence.

[0092] Finally, it should be pointed out that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A hydrogen energy testing power supply circuit integrating EIS function, characterized in that: It includes an electrolytic cell interface, a control module, and an EIS test module and an electrolytic power supply module electrically connected to the control module; The electrolysis power supply module includes a current / voltage sampling unit and a power drive unit, and the control module is electrically connected to the electrolytic cell interface through the current / voltage sampling unit and the power drive unit, respectively. The EIS testing module includes a data acquisition chip, a voltage acquisition circuit, a differential conditioning amplifier circuit, an analog switch switching circuit, a first AC / DC separation circuit, a second AC / DC separation circuit, a voltage-to-constant-current circuit, and a calibration resistor. The control module is electrically connected to the electrolytic cell interface through the voltage acquisition circuit. The control module is also electrically connected to the voltage-to-constant-current circuit and the differential conditioning amplifier circuit through the data acquisition chip. The voltage-to-constant-current circuit is connected to the electrolytic cell interface through the calibration resistor. The first AC / DC separation circuit is connected in parallel across the calibration resistor. The differential amplifier circuit is electrically connected to the first AC / DC separation circuit and the second AC / DC separation circuit through the analog switch switching circuit. The second AC / DC separation circuit is electrically connected to the electrolytic cell interface.

2. The hydrogen energy testing power supply circuit with integrated EIS function according to claim 1, characterized in that: The current / voltage sampling unit includes a current detection and conditioning circuit, a current sampling resistor, a voltage detection and conditioning circuit, and a sampling chip; the control module is electrically connected to the current detection and conditioning circuit and the voltage detection and conditioning circuit respectively through the sampling chip; the current detection and conditioning circuit is electrically connected to the current sampling resistor; the voltage detection and conditioning circuit is electrically connected to the electrolytic cell interface; The power drive unit includes a gate drive circuit and a MOSFET switching circuit; the control module is electrically connected to the current sampling resistor in sequence through the gate drive circuit and the MOSFET switching circuit; the current sampling resistor is electrically connected to the electrolytic cell interface.

3. The hydrogen energy testing power supply circuit with integrated EIS function according to claim 1, characterized in that: The voltage-to-constant-current circuit includes several power transistors connected in parallel, operational amplifier U7, operational amplifier U8A, operational amplifier U8B, and several capacitors and resistors connected around the operational amplifiers U7, U8A, and U8B. The non-inverting input of operational amplifier U7 is electrically connected to the acquisition chip; the output of operational amplifier U7 is electrically connected to the non-inverting input of operational amplifier U8A; the inverting input of operational amplifier U8A is electrically connected to the output of operational amplifier U8B; the output of operational amplifier U8A is electrically connected to the gate of the power transistor; the non-inverting and inverting inputs of operational amplifier U8B are electrically connected to the source of the power transistor; and the drain of the power transistor is electrically connected to the calibration resistor.

4. The hydrogen energy testing power supply circuit with integrated EIS function according to claim 2, characterized in that: The first AC / DC separation circuit includes capacitor C31, capacitor C33, resistor R39, resistor R41, resistor R38, resistor R42, and low-pass filter LPF0. The first terminals of capacitors C31 and C33 are connected in parallel across the calibration resistor. The second terminal of capacitor C31 is electrically connected to resistors R39 and R38. Resistor R39 is electrically connected to the low-pass filter LPF0. The second terminal of capacitor C33 is electrically connected to resistors R41 and R42. Resistor R41 is electrically connected to the low-pass filter LPF0. Resistors R38 and R42 are electrically connected to the analog switch circuit. The second AC / DC separation circuit includes capacitor C28, capacitor C30, resistor R35, resistor R36, resistor R10, resistor R37, and low-pass filter LPF0; the first terminals of capacitors C28 and C30 are electrically connected to the electrolytic cell interface; the second terminal of capacitor C28 is electrically connected to resistors R35 and R10; resistor R35 is electrically connected to the low-pass filter LPF0; the second terminal of capacitor C30 is electrically connected to resistors R36 and R37; resistor R36 is electrically connected to the low-pass filter LPF0; and resistors R10 and R42 are electrically connected to the analog switch switching circuit.

5. The hydrogen energy testing power supply circuit with integrated EIS function according to claim 2, characterized in that: The electrolytic cell interface includes a positive power line, a negative power line, a positive voltage detection line, and a negative voltage detection line; the hydrogen energy testing power supply circuit also includes relays K1, K2, K3, and K4; each of relays K1, K2, K3, and K4 has a first set of switch contacts and a second set of switch contacts. The first set of switch contacts of relay K1 is connected to the positive power line and the current sampling resistor respectively; the second set of switch contacts of relay K1 is connected to the negative power line and the current sampling resistor respectively; the first set of switch contacts of relay K2 is connected to the positive voltage detection line and the voltage detection circuit respectively; the second set of switch contacts of relay K2 is connected to the negative voltage detection line and the voltage detection circuit respectively. The first set of switch contacts of relay K3 is connected to the positive power line and the power supply respectively; the second set of switch contacts of relay K3 is connected to the positive voltage detection line and the second AC / DC separation circuit respectively; the first set of switch contacts of relay K4 is connected to the negative voltage detection line and the second AC / DC separation circuit respectively; the second set of switch contacts of relay K4 is connected to the negative power line and the calibration resistor respectively. By controlling relays K1, K2, K3, and K4, the system can switch between operating as an EIS test module for EIS testing and as an electrolytic power supply module for polarization testing.

6. The hydrogen energy testing power supply circuit with integrated EIS function according to claim 1, characterized in that: The differential conditioning amplifier circuit includes operational amplifiers U10A, U10B, U10C, and U10D, resistors R68, R69, R72, R71, R74, and R75, capacitors C54 and C56, resistors R70, R67, R73, and R76. The non-inverting input terminals of operational amplifiers U10A and U10C are electrically connected to the analog switch circuit; the inverting input terminals of operational amplifiers U10A and U10C are electrically connected to each other through resistor R71; one output terminal of operational amplifier U10A is electrically connected to the inverting input terminal of operational amplifier U10A through resistor R69, and the other output terminal is connected to the input power supply through capacitor C54 and resistor R68; one input terminal of operational amplifier U10C is electrically connected to the inverting input terminal of operational amplifier U10C through resistor R74, and the other input terminal is connected to the input power supply through capacitor C56 and resistor R75. The inverting input terminals of operational amplifiers U10B and U10D are electrically connected to each other via resistor R72; the non-inverting input terminal of operational amplifier U10B is connected to the output terminal of operational amplifier U10A via capacitor C54; the non-inverting input terminal of operational amplifier U10D is electrically connected to the output terminal of operational amplifier U10C via capacitor C56; one output terminal of operational amplifier U10B is electrically connected to the inverting input terminal of operational amplifier U10B via resistor R70, and the other output terminal is electrically connected to the acquisition chip via resistor R67; one output terminal of operational amplifier U10D is electrically connected to the inverting input terminal of operational amplifier U10D via resistor R73, and the other output terminal is electrically connected to the acquisition chip via resistor R76.

7. The hydrogen energy testing power supply circuit with integrated EIS function according to claim 1, characterized in that: The control module includes a first control chip and a second control chip. The first control chip is electrically connected to the electrolysis power supply module, and the second control chip is electrically connected to the EIS test module.

8. The hydrogen energy testing power supply circuit with integrated EIS function according to claim 1, characterized in that: The acquisition chip is model AD5941 or AD5940.

9. A hydrogen energy testing system, characterized in that: The hydrogen energy test power supply circuit with integrated EIS function as described in any one of claims 1-8 is adopted.

10. A test method for a hydrogen energy test power supply circuit, characterized in that: The test circuit employs the integrated EIS function hydrogen energy test power supply circuit as described in any one of claims 1-8 or the hydrogen energy test system as described in claim 9; it also includes the following test methods: When the current of the electrolytic cell is less than or equal to the preset normal operating current of the electrolytic cell, the electrolytic power supply module does not work, and the EIS test module works to perform EIS testing. During EIS testing, the EIS test module applies a constant current signal consisting of an adjustable small-amplitude AC signal and a DC bias signal superimposed on the electrolytic cell, and obtains the impedance parameters of the electrolytic cell by comparing the AC response signal of the electrolytic cell with the AC voltage signal of the calibration resistor. When the current in the electrolytic cell is greater than the preset normal operating current of the electrolytic cell, the EIS test module does not work, and the electrolytic power supply module works to perform polarization testing; during polarization testing, a predetermined current transition or voltage transition is applied to the electrolytic cell through the power drive unit. While applying current or voltage transitions, the voltage and current of the electrolytic cell are acquired through the current / voltage sampling unit to obtain the polarization behavior of the electrolytic cell.

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