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

Abstract

The invention relates to the technical field of hydrogen energy, in particular to a hydrogen energy test power supply circuit, system and method integrated with an 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 amplification circuit, an analog switch switching circuit, a first alternating current and direct current separation circuit, a second alternating current and direct current separation circuit, a voltage-to-constant current circuit and a calibration resistor. The control module is electrically connected with the electrolytic cell interface through a voltage acquisition circuit, and is electrically connected with the voltage-to-constant current circuit and the differential conditioning amplification circuit through an 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 with two ends of the calibration resistor. The differential amplification circuit is electrically connected with the first alternating-current and direct-current separation circuit and the second alternating-current and direct-current separation circuit through the analog switch switching circuit, and the second alternating-current and direct-current separation circuit is electrically connected with the electrolytic cell interface.

Description

Technical Field

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

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

[0003] However, in existing water electrolysis hydrogen production devices, the electrolysis power supply and AC impedance test equipment are usually two independent devices, which need to be independently controlled by two softwares. This operation method makes the operation process cumbersome and inconvenient to use. In addition, when the existing water electrolysis hydrogen production device performs AC impedance testing, the electrolysis power supply uses a constant current source with digital control, which not only has switching noise, but also easily affects the test accuracy of electrochemical impedance spectroscopy (EIS); when performing EIS testing, usually only a small AC disturbance signal can be applied, and a DC bias current similar to the larger electrolysis voltage cannot be provided, thereby limiting the scope of application of the test. Summary of the invention

[0004] In order to solve at least one of the shortcomings of the water electrolysis hydrogen production device in the above-mentioned prior art, the present invention provides a hydrogen energy test power supply circuit with integrated EIS function, including an electrolyzer interface, a control module, and an EIS test module electrically connected to the control module, and an electrolysis power supply module; The electrolysis power supply module includes a current / voltage sampling unit and a power driving unit, and the control module is electrically connected to the electrolytic cell interface through the current / voltage sampling unit and the power driving unit respectively; The EIS test module includes an 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 respectively 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 to both ends of the calibration resistor; the differential amplifier circuit is electrically connected to the first AC / DC separation circuit and the second AC / DC separation circuit respectively through the analog switch switching circuit, and the second AC / DC separation circuit is electrically connected to the electrolytic cell interface; When performing an EIS test, the acquisition chip applies a constant current signal that is a superposition of an adjustable small-amplitude AC signal and a DC bias signal to the electrolytic cell through the voltage-to-constant current circuit; at the same time, the AC response signal of the electrolytic cell is obtained through the second AC / DC separation circuit, the analog switch switching circuit and the differential conditioning amplifier circuit, and the AC 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 amplifier circuit; the impedance parameters of the electrolytic cell are obtained by comparing the AC response signal of the electrolytic cell with the AC voltage signal of the calibration resistor.

[0005] 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 to the current detection conditioning circuit and the voltage detection conditioning circuit through the sampling chip; the current detection conditioning circuit is electrically connected to the current sampling resistor; the voltage detection conditioning circuit is electrically connected to the electrolytic cell interface; The power drive unit includes a gate drive circuit and a MOS tube switch circuit; the control module is electrically connected to the current sampling resistor through the gate drive circuit and the MOS tube switch circuit in sequence; and the current sampling resistor is electrically connected to the electrolytic cell interface.

[0006] In some embodiments, the voltage-to-constant current circuit includes a plurality of power transistors, an operational amplifier U7, an operational amplifier U8A, an operational amplifier U8B connected in parallel, 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; 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 reverse 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 reverse input terminal of the operational amplifier U8B are electrically connected to the source of the power transistor; the drain of the power transistor is electrically connected to the calibration resistor.

[0007] 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 capacitors C31 and C33 are respectively connected in parallel to the two ends of the calibration resistor; the second end of the capacitor C31 is respectively electrically connected to the resistor R39 and the resistor R38; the resistor R39 is electrically connected to the low-pass filter LPF0; the second end of the capacitor C33 is respectively electrically connected to the resistor R41 and the resistor R42; the resistor R41 is electrically connected to the low-pass filter LPF0; the 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 ends of the capacitor C28 and capacitor C30 are electrically connected to the electrolytic cell interface respectively; the second end of the capacitor C28 is electrically connected to the resistor R35 and resistor R10 respectively; the resistor R35 is electrically connected to the low-pass filter LPF0; the second end of the capacitor C30 is electrically connected to the resistor R36 and resistor R37 respectively; the resistor R36 is electrically connected to the low-pass filter LPF0; the resistor R10 and resistor R42 are electrically connected to the analog switch circuit.

[0008] In some embodiments, the electrolyzer 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 also includes a relay K1, a relay K2, a relay K3, and a relay K4; the relay K1, the relay K2, the relay K3, and the relay K4 all have a first set of switch contacts and a second set of switch contacts; The first group of switch contacts of the relay K1 are respectively connected to the positive power line and the current sampling resistor; the second group of switch contacts of the relay K1 are respectively connected to the negative power line and the current sampling resistor; the first group of switch contacts of the relay K2 are respectively connected to the positive voltage detection line and the voltage detection circuit; the second group of switch contacts of the relay K2 are respectively connected to the negative voltage detection line and the voltage detection circuit; The first group of switch contacts of the relay K3 are respectively connected to the positive power line and the power supply; the second group of switch contacts of the relay K3 are respectively connected to the positive voltage detection line and the second AC / DC separation circuit; the first group of switch contacts of the relay K4 are respectively connected to the negative voltage detection line and the second AC / DC separation circuit; the second group of switch contacts of the relay K4 are respectively connected to the negative power line and the calibration resistor; By controlling the relay K1, the relay K2, the relay K3 and the relay K4, the operation can be switched to the EIS test module to perform the EIS test or switched to the electrolysis power supply module to perform the polarization test.

[0009] In some embodiments, the differential conditioning amplifier circuit includes an operational amplifier U10A, an operational amplifier U10B, an operational amplifier U10C, an operational amplifier U10D, a resistor R68, a resistor R69, 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; The non-inverting input terminals of the operational amplifier U10A and the operational amplifier U10C are electrically connected to the analog switch 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 is connected to the input power supply through the capacitor C54 and the resistor R68 in the other 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 is connected to the input power supply through the capacitor C56 and the resistor R75 in the other way; 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 is electrically connected to the acquisition chip through the resistor R67 in the other 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 is electrically connected to the acquisition chip through the resistor R76 in the other way.

[0010] In some embodiments, 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.

[0011] In some embodiments, the acquisition chip is AD5941 or AD5940.

[0012] An embodiment of the present invention further provides a hydrogen energy testing system, which adopts the hydrogen energy testing power supply circuit with integrated EIS function as described in any of the above embodiments.

[0013] The embodiment of the present invention further provides a method for testing a hydrogen energy test power supply circuit, using the hydrogen energy test power supply circuit with integrated EIS function as described in any embodiment or using the hydrogen energy test system as described in the above embodiment; and also includes the following testing method: When the current of the electrolytic cell is less than or equal to the normal working current preset by the electrolytic cell, the electrolysis power supply module does not work, and the EIS test module works to perform the EIS test; when performing the EIS test, the EIS test module applies a constant current signal superimposed by an adjustable small-amplitude AC signal and a DC bias signal to 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 of the electrolytic cell is greater than the preset normal working current of the electrolytic cell, the EIS test module does not work, and the electrolysis power supply module works to perform a polarization test; when performing the polarization test, a predetermined current transition or voltage transition is applied to the electrolytic cell through the power drive unit; while applying the current transition or voltage transition, the voltage and current of the electrolytic cell are collected through the current / voltage sampling unit to obtain the polarization behavior of the electrolytic cell.

[0014] Based on the above, compared with the prior art, the hydrogen energy test power supply circuit with integrated EIS function provided by the present invention integrates polarization test and EIS test functions in a miniaturized manner through circuit design of each electrolysis power supply module and EIS test module, and has a simple structure, small size, low cost, no switching 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 a large-amplitude DC bias current, which can effectively improve the accuracy and diversity of the EIS test.

[0015] Other features and beneficial effects of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other beneficial effects of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. The positional relationships described in the drawings in the following description are based on the directions in which the components are drawn in the diagrams, unless otherwise specified.

[0017] Figure 1A circuit module block diagram of a hydrogen energy test power supply circuit with integrated EIS function provided by one embodiment of the present invention; Figure 2 A circuit block diagram of a hydrogen energy test power supply circuit with integrated EIS function provided by another embodiment of the present invention; Figure 3 It is the circuit schematic diagram of the current / voltage sampling unit; Figure 4 This is the circuit schematic diagram of the power drive unit; Figure 5 The circuit schematic diagram of the acquisition chip; Figure 6 A circuit schematic diagram showing the connection of a voltage-to-constant current circuit, a first AC / DC separation circuit, a second AC separation circuit, and a calibration resistor; Figure 7 This is the circuit schematic diagram of the differential conditioning amplifier circuit. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments; the technical features designed in different implementation modes of the present invention described below can be combined with each other as long as they do not conflict with each other; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0019] In the description of the present invention, it should be noted that all terms (including technical terms and scientific terms) used in the present invention have the same meanings as those generally understood by ordinary technicians in the field to which the present invention belongs, and should not be understood as limitations on the present invention; it should be further understood that the terms used in the present invention should be understood to have the same meanings as these terms in the context of this specification and in the relevant fields, and should not be understood in an idealized or overly formal sense, unless explicitly defined in this invention.

[0020] At present, the hydrogen production power supply of the existing water electrolysis hydrogen production device generally adopts 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 practical applications: 1. The existing electrolysis power supply and AC impedance test equipment are usually two independent devices, each of which requires independent software for control. This separate control system leads to complex operation, inconvenience in use, and increases the burden on the operator. 2. When performing AC impedance testing, since the electrolysis power supply adopts a constant current source with digital control, its switching action 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 AC impedance test equipment for EIS testing, a small AC disturbance signal, such as 100mA, is usually applied. This small AC signal cannot provide a large DC bias current similar to that required for actual electrolysis during the electrolysis process, which limits the practicality and relevance of the test. 4. The existing electrolysis power supply and electrochemical workstation equipment are large in size and difficult to achieve miniaturization and integration. This not only limits the portability of the device, but also increases the manufacturing and maintenance costs of the device, making the overall system more expensive.

[0021] In order to effectively solve at least one of the above problems, the present invention provides a hydrogen energy test power supply circuit, system and method with integrated EIS function, which will be described in detail below based on specific embodiments and drawings.

[0022] Embodiment 1 See also Figure 1 An embodiment of the present invention provides a hydrogen energy test power supply circuit with integrated EIS function. The hydrogen energy test power supply circuit with integrated EIS function includes at least an electrolytic cell interface, a control module, and an EIS test module and an electrolysis power supply module electrically connected to the control module.

[0023] Wherein, the control module may include an MCU or other processor. Preferably, the control module is provided with a communication interface for communicating with a host computer, and transmitting corresponding control instructions and data information. In the present embodiment, the preferred control module includes a first control chip and a second control chip, wherein the first control chip is electrically connected to the electrolysis power module, and the second control chip is electrically connected to the EIS test module. Wherein the first control chip is used to control the operation of the electrolysis power module, and the second control chip is used to control the operation of the EIS test module; 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 relevant peripheral circuits, which can be designed according to actual needs, and are not limited here.

[0024] The electrolysis power supply module comprises a current / voltage sampling unit and a power driving unit, and the control module is electrically connected to the electrolytic cell interface through the current / voltage sampling unit and the power driving unit respectively.

[0025] During specific implementation, the current / voltage sampling unit is used to collect current and voltage from the electrolytic cell and feed it back to the control module, which can be achieved through sampling resistors and resistor voltage divider circuits; the power drive unit is used to control the switching of the power switching device, specifically through the relevant drive circuit to amplify the PWM (pulse width modulation) signal generated by the digital control core to drive the power switching device; the specific circuit connections of the current / voltage sampling unit and the power drive unit are existing conventional designs and are not limited here.

[0026] See also Figure 2 In this embodiment, the current / voltage sampling unit preferably 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 to the current detection conditioning circuit and the voltage detection conditioning circuit respectively through the sampling chip; the current detection conditioning circuit is electrically connected to the current sampling resistor; and the voltage detection conditioning circuit is electrically connected to the electrolytic cell interface.

[0027] Specific as Figure 4 As shown, the current detection and conditioning circuit includes an operational amplifier U1 and an operational amplifier U4 connected to each other, and a number of capacitors and resistors electrically connected to the operational amplifier U1 and the operational amplifier U4; wherein the two-stage operational amplifier is used to accurately amplify the current signal flowing through the current sampling resistor, and transmit the amplified current signal to the sampling chip, which performs analog-to-digital conversion and transmits it 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 number of capacitors and resistors electrically connected to the operational amplifier U3B; similarly, the operational amplifier is used to amplify and condition the voltage signal, and transmit the voltage signal to the sampling chip, which performs analog-to-digital conversion and transmits it to the control module, so that the control module can accurately obtain the voltage of the electrolytic cell.

[0028] Please continue reading Figure 2 In this embodiment, the power drive unit preferably includes a gate drive circuit and a MOS tube switch circuit; the control module is electrically connected to the current sampling resistor through the gate drive circuit and the MOS tube switch circuit in sequence; and the current sampling resistor is electrically connected to the electrolytic cell interface.

[0029] See also Figure 4The gate drive circuit mainly includes a drive chip U2 and surrounding circuits, wherein the drive chip U2 is used to generate a signal suitable for driving the MOS tube in the MOS tube switch circuit according to the control signal generated by the control module to control the switch of the MOS tube. The MOS tube switch circuit includes one or more MOS tubes to control the current to flow to the electrolytic cell. In this embodiment, the MOS tube switch circuit includes MOS tube Q1, MOS tube Q2, MOS tube Q3, and MOS tube Q4. In addition, multiple groups of capacitors are connected in parallel on the input side and the output side of the MOS tube switch circuit for filtering and providing a stable voltage for the electrolytic cell.

[0030] For further information, please refer to Figure 4 The electrolysis power supply module also includes a temperature detection circuit, wherein a sensor of the temperature detection circuit is arranged near the MOS tube to monitor the temperature of the MOS tube in real time to prevent the MOS tube from being damaged due to overheating.

[0031] See also Figure 2 The EIS test module includes an 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 respectively 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 to both ends of the calibration resistor; the differential amplifier circuit is electrically connected to the first AC / DC separation circuit and the second AC / DC separation circuit respectively through the analog switch switching circuit, and the second AC / DC separation circuit is electrically connected to the electrolytic cell interface.

[0032] During specific implementation, the acquisition chip is used to collect the response signal of the electrolytic cell to obtain the impedance spectrum data of the EIS test on the one hand, and on the other hand, it is used to output an AC voltage signal with an adjustable DC bias amplitude and an adjustable superimposed amplitude / frequency and applied to the electrolytic cell through a voltage-to-constant current circuit. In this embodiment, the preferred acquisition chip model is AD5941 or AD5940. Taking AD5941 as an example, it has an internal integrated DAC, ADC, digital waveform generator, and complex impedance measurement (DFT) engine. The real and imaginary parts of the impedance can be calculated inside the chip, thereby effectively obtaining the impedance spectrum data. Among them, the circuit diagram of the acquisition chip model AD5941 and related surrounding circuits can be referred to. Figure 5 shown.

[0033] The input end of the voltage-to-constant current circuit is electrically connected to the acquisition chip, and the output end is electrically connected to the electrolytic cell interface through a calibration resistor, so as to convert the AC voltage signal output by the acquisition chip into a constant current signal, and apply the constant current signal to the electrolytic cell through the calibration resistor, thereby effectively ensuring that the current applied to the electrolytic cell and the calibration resistor is constant. That is, since the impedance of the electrolytic cell is variable, the use of a constant current source can ensure the stability of the excitation signal, thereby obtaining a more accurate impedance measurement result. In addition, the current value of the constant current signal can be adjusted by adjusting the AC voltage signal output by the acquisition chip, and the electrochemical impedance spectrum of the electrolytic cell can be obtained by adjusting and analyzing the AC current amplitude and phase at different frequencies.

[0034] Furthermore, the DC bias amplitude of the acquisition chip output is adjustable and the AC voltage signal with adjustable superposition amplitude / frequency is converted into a constant current signal through a voltage constant current circuit and applied to the electrolyzer through a calibration resistor. The electrolyzer responds to the applied constant current signal to form a response signal of the electrolyzer to AC excitation. Since the electrochemical impedance of the electrolyzer changes with the frequency of the applied signal, the amplitude and phase of the AC current of the response signal will also change with the change of frequency. Therefore, when performing an EIS test, since the constant current signal applied to the electrolyzer contains an AC component and a DC component, when extracting the constant current signal applied to the electrolyzer and the response signal of the electrolyzer to AC excitation, it is necessary to retain the AC component while removing the DC component to effectively complete the subsequent impedance analysis.

[0035] Based on this, the present embodiment designs a first AC / DC separation circuit and a second AC / DC separation circuit. The first AC / DC separation circuit is electrically connected to the electrolytic cell interface, and is used to separate the AC component (i.e., the AC response signal) from the response signal of the electrolytic cell to AC excitation, which is used for subsequent impedance analysis. The second AC / DC separation circuit is connected in parallel at both ends of the calibration resistor, and is used to separate the AC component (i.e., the AC voltage signal) from the constant current signal flowing through the calibration resistor, which is also used for subsequent impedance analysis. The first AC / DC separation circuit and the second AC / DC separation circuit both include low-pass filters to allow low-frequency AC signals to pass through and prevent high-frequency DC signals from passing through. The specific circuit connection method can be designed according to actual needs, and the present embodiment is not limited thereto.

[0036] The analog switch switching circuit is electrically connected to the first AC / DC separation circuit and the second AC / DC separation circuit respectively, so as to switch different circuit paths according to the actual EIS test requirements. Specifically, a quick switch is performed between the measuring electrolytic cell and the standard resistor so as to measure the AC response signal of the electrolytic cell and the AC voltage signal of the calibration resistor respectively in different test stages, thereby facilitating the elimination of DC offset and gain errors in the measurement system. Preferably, the analog switch switching circuit can use a transistor or an integrated analog switch as a switch.

[0037] Since the response signal and constant current signal of the AC disturbance are relatively small, at the level of tens of milliohms, the AC response signal and AC voltage signal obtained after AC-DC separation are even smaller, so it is necessary to enter the acquisition chip after differential amplification. Therefore, in this embodiment, the input end of the differential conditioning amplifier circuit is respectively connected to the first AC-DC separation circuit and the second AC-DC separation circuit through an analog switch switching circuit, and the output end is electrically connected to the acquisition chip, which is not only used to amplify the smaller AC response signal and AC voltage signal collected by the electrolytic cell and the calibration resistor, so as to facilitate the acquisition chip to perform AD conversion and processing; it can also effectively suppress common-mode interference and improve the quality of the signal. In this embodiment, the differential conditioning amplifier circuit preferably uses multiple operational amplifiers to form a differential amplifier circuit, and cooperates with a number of resistors and capacitors to achieve gain adjustment and filtering processing, etc., and is specifically set according to actual needs.

[0038] 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 electrically connected to the electrolytic cell interface through the voltage acquisition circuit; the specific voltage acquisition circuit can use a suitable chip and circuit to collect the voltage signal of the electrolytic cell in real time. The specific circuit is an existing conventional design and will not be described in detail here.

[0039] In summary, when performing an EIS test, the acquisition chip applies an adjustable small-amplitude AC signal and a constant current signal superimposed by a DC bias signal to the electrolytic cell through the voltage-to-constant current circuit. Among them, by superimposing a DC bias signal, not only can the double-layer effect of the electrode be reduced, the electrode potential be stabilized and controlled, so that the measurement result is closer to the actual working state and the measurement accuracy is improved; it can also simulate the actual operating conditions of the system cabinet, which is helpful to study the mixed effect of AC and DC in the system, and provide a more in-depth study for analyzing EIS tests.

[0040] At the same time, when performing the 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 amplifier 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 amplifier circuit; the impedance parameters of the electrolytic cell are obtained by comparing the AC response signal of the electrolytic cell with the AC voltage signal of the calibration resistor. Specifically, since the current flowing through the electrolytic cell and the calibration resistor is the same, 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, U load is the AC response signal of the electrolytic cell, U RACL is the AC voltage signal for calibrating the resistor.

[0041] It should be noted that each of the above modules can be designed using existing conventional circuits or computer programs according to specific functions, and will not be described in detail here.

[0042] In order to effectively illustrate the function and effect of the EIS test module provided by the embodiment of the present invention, a specific circuit connection principle diagram of the EIS test module is used as an example for detailed description below in conjunction with the accompanying drawings.

[0043] See also Figure 6 The voltage-to-constant-current circuit includes a plurality of power transistors, an operational amplifier U7, an operational amplifier U8A, an operational amplifier U8B connected in parallel, 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; 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 reverse 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 reverse input terminal of the operational amplifier U8B are electrically connected to the source of the power transistor; the drain of the power transistor is electrically connected to the calibration resistor.

[0044] Among them, the power transistor is used to realize the conversion from 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 consumed by the power transistor, this 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 the four power transistors Q5, power transistor Q6, power transistor Q7, and power transistor Q8 shown in the drawings, and is specifically set according to actual needs.

[0045] Operational amplifier U7, operational amplifier U8A, and operational amplifier U8B constitute the control part of the voltage-to-constant current circuit, which can adjust and stabilize the output current. The capacitors and resistors connected to the periphery of operational amplifier U7, operational amplifier U8A, and operational amplifier U8B are used to realize functions such as filtering, feedback, and biasing.

[0046] Through the 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.

[0047] Please continue reading Figure 6 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 capacitors C31 and C33 are respectively connected in parallel to the two ends of the calibration resistor; the second end of the capacitor C31 is respectively electrically connected to the resistor R39 and the resistor R38; the resistor R39 is electrically connected to the low-pass filter LPF0; the second end of the capacitor C33 is respectively electrically connected to the resistor R41 and the resistor R42; the resistor R41 is electrically connected to the low-pass filter LPF0; the 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 ends of the capacitor C28 and capacitor C30 are electrically connected to the electrolytic cell interface respectively; the second end of the capacitor C28 is electrically connected to the resistor R35 and resistor R10 respectively; the resistor R35 is electrically connected to the low-pass filter LPF0; the second end of the capacitor C30 is electrically connected to the resistor R36 and resistor R37 respectively; the resistor R36 is electrically connected to the low-pass filter LPF0; the resistor R10 and resistor R42 are electrically connected to the analog switch circuit.

[0048] See also Figure 7The differential conditioning amplifier circuit includes an operational amplifier U10A, an operational amplifier U10B, an operational amplifier U10C, an operational amplifier U10D, a resistor R68, a resistor R69, a resistor R69, 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.

[0049] The non-inverting input terminals of the operational amplifier U10A and the operational amplifier U10C are electrically connected to the analog switch 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 is connected to the input power supply through the capacitor C54 and the resistor R68 in the other 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 is connected to the input power supply through the capacitor C56 and the resistor R75 in the other way. 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 is electrically connected to the acquisition chip through the resistor R67 in the other 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 is electrically connected to the acquisition chip through the resistor R76 in the other way.

[0050] Through the above-mentioned effective design of the operational amplifier and several resistors, differential amplification of the input signal can be achieved, wherein the amplification factor can be adjusted by adjusting the resistance values ​​of resistors R69, R71, R74, R70, R73, and R72.

[0051] Furthermore, in order to effectively control the switching of the polarization test and the EIS test of the electrolytic cell, this embodiment preferably uses multiple groups of relays for implementation. Figure 2 , Figure 3 , Figure 6The electrolyzer 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 also includes relays K1, K2, K3, and K4; the relays K1, K2, K3, and K4 all have a first set of switch contacts and a second set 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 simplified schematic diagrams. Figure 3 , Figure 6 In specific applications, the corresponding relays are relay K1, relay K2, relay K3, and relay K4.

[0052] The first group of switch contacts of the relay K1 are respectively connected to the positive power line and the current sampling resistor; the second group of switch contacts of the relay K1 are respectively connected to the negative power line and the current sampling resistor; the first group of switch contacts of the relay K2 are respectively connected to the positive voltage detection line and the voltage detection circuit; the second group of switch contacts of the relay K2 are respectively connected to the negative voltage detection line and the voltage detection circuit; the first group of switch contacts of the relay K3 are respectively connected to the positive power line and the power supply; the second group of switch contacts of the relay K3 are respectively connected to the positive voltage detection line and the second AC / DC separation circuit; the first group of switch contacts of the relay K4 are respectively connected to the negative voltage detection line and the second AC / DC separation circuit; the second group of switch contacts of the relay K4 are respectively connected to the negative power line and the calibration resistor.

[0053] By the above-mentioned control of relay K1, relay K2, relay K3, and relay K4, the EIS test module can be switched to work to perform EIS test or switched to work of electrolysis power supply module to perform polarization test; Specifically, when relay K1 and relay K2 are closed and relay K3 and relay K4 are disconnected, the EIS test module is not connected to the electrolyzer, and the electrolysis power supply module is connected to the electrolyzer for polarization test. On the contrary, when relay K1 and relay K2 are disconnected and relay K3 and relay K4 are closed, the EIS test module is connected to the electrolyzer for EIS test, and the electrolysis power supply module is not connected to the electrolyzer. In addition, by the switching design of the relay, when performing the EIS test, since the electrolysis power supply does not work, there will be no switching noise because the electrolysis power supply is a constant current source of a digital control method, and the accuracy of the EIS test will not be affected.

[0054] It should be noted that those skilled in the art may make corresponding circuit connection changes with reference to the functions and connection relationships of the above-mentioned circuits, which shall all fall within the protection scope of the present invention.

[0055] Embodiment 2 The embodiment of the present invention also provides a hydrogen energy testing system, which uses a hydrogen energy testing power supply circuit with integrated EIS function as described in any of the above embodiments. The hydrogen energy testing system integrates the electrolysis power supply and the EIS testing scheme in a miniaturized manner, has a simple structure, low cost, and can be effectively applied to the testing of water electrolysis process devices. Among them, the specific circuit design of the hydrogen energy testing power supply circuit with integrated EIS function can be referred to as shown above, and will not be repeated here.

[0056] Preferably, the hydrogen energy test system further includes a host computer, and the host computer (such as a PC) is connected to the hydrogen energy test power supply circuit via wired or wireless communication to transmit corresponding data information, for example, using USB to achieve communication connection.

[0057] Embodiment 3 The embodiment of the present invention also provides a method for testing a hydrogen energy test power supply circuit, using the hydrogen energy test power supply circuit with integrated EIS function as described in the above embodiment or using the hydrogen energy test system as described in the above embodiment. The specific structure, circuit design, and function of the hydrogen energy test power supply circuit with integrated EIS function and the hydrogen energy test system can be referred to in Embodiment 1 and Embodiment 2, and will not be described in detail here.

[0058] The test method of the hydrogen energy test power supply circuit comprises the following steps: When the current of the electrolytic cell is less than or equal to the normal working current preset by the electrolytic cell, the electrolysis power supply module does not work, and the EIS test module works to perform the EIS test; when performing the EIS test, the EIS test module applies a small-amplitude AC signal and a DC bias signal to 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 of the electrolytic cell is greater than the preset normal working current of the electrolytic cell, the EIS test module does not work, and the electrolysis power supply module works to perform a polarization test; when performing the polarization test, a predetermined current transition or voltage transition is applied to the electrolytic cell through the power drive unit; while applying the current transition or voltage transition, the voltage and current of the electrolytic cell are collected through the current / voltage sampling unit to obtain the polarization behavior of the electrolytic cell.

[0059] Through the above settings, it is possible to switch according to different test state requirements. When a small-amplitude AC disturbance is applied in the EIS test, a certain DC bias signal can be applied, and the electrolysis power module does not work; when a relatively large current is required for the 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 cell as an example, which is usually 4A (working conditions), when the current is less than or equal to 4A, the EIS test module can output a transverse current signal with a 4A DC bias and a small-amplitude AC signal superimposed; when the current is greater than 4A, the EIS test module does not work, and only the electrolysis power module works.

[0060] In summary, compared with the prior art, the hydrogen energy test power supply circuit, system and method with integrated EIS function provided by the present invention have the following advantages: 1. Through the circuit design of the electrolysis power module and the EIS test module, the two functions of polarization test and EIS test can be effectively realized, without the need for independent equipment to perform independent control tests, and can be effectively applied to electrolytic cell detection under various working conditions; Second, the polarization test or EIS test can be switched independently according to different current states, which is easy to operate. And when performing the EIS test, there will be no switching noise because the electrolysis power supply is a constant current source with digital control mode, which will not affect the accuracy of the EIS test; 3. The EIS test module can not only apply small AC disturbance signals but also provide large DC bias current, which can effectively and accurately perform EIS tests; 4. Simple structure, small size, low cost, effectively realizing miniaturized and integrated testing functions.

[0061] 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 invention can be improved in only one or several aspects, without having to solve all the technical problems listed in the prior art or background technology at the same time. Those skilled in the art should understand that the content not mentioned in a claim should not be used as a limitation on the claim.

[0062] Although the terms such as electrolyzer interface, control module, EIS test module, electrolysis power module, etc. are used more frequently in this article, the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional restrictions is contrary to the spirit of the present invention; the terms "first", "second", etc. (if any) in the description and claims of the embodiments of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hydrogen energy test power supply circuit with integrated EIS function, characterized in that: It includes an electrolytic cell interface, a control module, an EIS test module electrically connected to the control module, and an electrolysis power supply module; The electrolysis power supply module includes a current / voltage sampling unit and a power driving unit, and the control module is electrically connected to the electrolytic cell interface through the current / voltage sampling unit and the power driving unit respectively; The EIS test module includes an 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 respectively 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 to both ends of the calibration resistor; the differential amplifier circuit is electrically connected to the first AC / DC separation circuit and the second AC / DC separation circuit respectively through the analog switch switching circuit, and the second AC / DC separation circuit is electrically connected to the electrolytic cell interface.

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

3. The hydrogen energy test power supply circuit with integrated EIS function according to claim 1, characterized in that: The voltage-to-constant-current circuit includes a plurality of power transistors, an operational amplifier U7, an operational amplifier U8A, an operational amplifier U8B connected in parallel, 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; 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 reverse 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 reverse input terminal of the operational amplifier U8B are electrically connected to the source of the power transistor; the drain of the power transistor is electrically connected to the calibration resistor.

4. The hydrogen energy test power supply circuit with integrated EIS function according to claim 2, characterized in that: 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 respectively connected in parallel to the two ends of the calibration resistor; the second end of the capacitor C31 is respectively electrically connected to the resistor R39 and the resistor R38; the resistor R39 is electrically connected to the low-pass filter LPF0; the second end of the capacitor C33 is respectively electrically connected to the resistor R41 and the resistor R42; the resistor R41 is electrically connected to the low-pass filter LPF0; the resistor R38 and the resistor 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 ends of the capacitor C28 and capacitor C30 are electrically connected to the electrolytic cell interface respectively; the second end of the capacitor C28 is electrically connected to the resistor R35 and resistor R10 respectively; the resistor R35 is electrically connected to the low-pass filter LPF0; the second end of the capacitor C30 is electrically connected to the resistor R36 and resistor R37 respectively; the resistor R36 is electrically connected to the low-pass filter LPF0; the resistor R10 and resistor R42 are electrically connected to the analog switch circuit.

5. The hydrogen energy test power supply circuit with integrated EIS function according to claim 2, characterized in that: The electrolyzer 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 also includes a relay K1, a relay K2, a relay K3, and a relay K4; the relay K1, the relay K2, the relay K3, and the relay K4 all have a first set of switch contacts and a second set of switch contacts; The first group of switch contacts of the relay K1 are respectively connected to the positive power line and the current sampling resistor; the second group of switch contacts of the relay K1 are respectively connected to the negative power line and the current sampling resistor; the first group of switch contacts of the relay K2 are respectively connected to the positive voltage detection line and the voltage detection circuit; the second group of switch contacts of the relay K2 are respectively connected to the negative voltage detection line and the voltage detection circuit; The first group of switch contacts of the relay K3 are respectively connected to the positive power line and the power supply; the second group of switch contacts of the relay K3 are respectively connected to the positive voltage detection line and the second AC / DC separation circuit; the first group of switch contacts of the relay K4 are respectively connected to the negative voltage detection line and the second AC / DC separation circuit; the second group of switch contacts of the relay K4 are respectively connected to the negative power line and the calibration resistor; By controlling the relay K1, the relay K2, the relay K3 and the relay K4, the operation can be switched to the EIS test module to perform the EIS test or switched to the electrolysis power supply module to perform the polarization test.

6. The hydrogen energy test power supply circuit with integrated EIS function according to claim 1, characterized in that: The differential conditioning amplifier circuit includes an operational amplifier U10A, an operational amplifier U10B, an operational amplifier U10C, an operational amplifier U10D, a resistor R68, a resistor R69, 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; The non-inverting input terminals of the operational amplifier U10A and the operational amplifier U10C are electrically connected to the analog switch 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 is connected to the input power supply through the capacitor C54 and the resistor R68 in the other 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 is connected to the input power supply through the capacitor C56 and the resistor R75 in the other way; 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 is electrically connected to the acquisition chip through the resistor R67 in the other 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 is electrically connected to the acquisition chip through the resistor R76 in the other way.

7. The hydrogen energy test 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, wherein 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 test power supply circuit with integrated EIS function according to claim 1, characterized in that: The model of the acquisition chip is AD5941 or AD5940.

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

10. A method for testing a hydrogen energy test power supply circuit, characterized in that: A hydrogen energy test power supply circuit with integrated EIS function as described in any one of claims 1 to 8 or a hydrogen energy test system as described in claim 9; further comprising the following test method: When the current of the electrolytic cell is less than or equal to the normal working current preset by the electrolytic cell, the electrolysis power supply module does not work, and the EIS test module works to perform the EIS test; when performing the EIS test, the EIS test module applies a constant current signal superimposed by an adjustable small-amplitude AC signal and a DC bias signal to 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 of the electrolytic cell is greater than the normal working current preset for the electrolytic cell, the EIS test module does not work, and the electrolysis power supply module works to perform a polarization test; when performing the polarization test, a predetermined current transition or voltage transition is applied to the electrolytic cell through the power drive unit; While applying the current jump or the voltage jump, the voltage and current of the electrolytic cell are collected by the current / voltage sampling unit to obtain the polarization behavior of the electrolytic cell.

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