An electrical performance calibration device and method for fusing electrolytic hydrogen production and hydrogen fuel cells

Abstract

The application provides a kind of fusion electrolytic hydrogen production and hydrogen fuel cell electrical performance calibration device and method, comprising: host computer, first digitized sampling voltmeter, second digitized sampling voltmeter, synchronous data acquisition card, synchronous inspection switch, current transformer, voltage transformer, electric pile, programmable power supply, self-calibration module, external calibration signal source;Synchronous inspection switch is used to detect the single-cell voltage bus of electric pile, then feedback to the sampling end of first digitized sampling voltmeter, the feedback end of first digitized sampling voltmeter is connected with the first input end of host computer;Current transformer is used to detect the current loop of electric pile;Voltage transformer is used to detect the total voltage of the electric pile;Programmable power supply is connected with the power supply wiring end of electric pile.The application solves the problems of poor synchronism, lack of self-calibration, low impedance measurement accuracy and bidirectional metering incompatibility when calibrating the electrical performance of electrolytic hydrogen production and hydrogen fuel cell.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical performance measurement and calibration of hydrogen energy equipment, and in particular to an electrical performance calibration device and method integrating electrolytic hydrogen production and hydrogen fuel cells. Background Art

[0002] The electrical performance calibration of hydrogen energy equipment is a core technical link to ensure the efficient operation of electrolytic hydrogen production systems and fuel cell systems. In the electrolytic hydrogen production scenario, the stack converts electrical energy into hydrogen energy, and parameters such as unit DC power consumption and hydrogen production efficiency need to be monitored in real time; in the hydrogen fuel cell scenario, the stack converts hydrogen energy into electrical energy, and indicators such as output power and energy conversion efficiency need to be accurately measured. The measurement error of its calibration device directly affects equipment status diagnosis, life prediction, and energy efficiency optimization. In particular, under highly fluctuating operating conditions (such as fluctuations in renewable energy power supply and load step changes), the dynamic characteristics of the voltage / current signal place demands on the calibration technology. The existing technology mainly has the following limitations:

[0003] 1. Insufficient single-cell voltage synchronization capability and lack of self-calibration mechanism:

[0004] There are many problems with the existing fuel cell single-cell voltage inspection technology, such as low utilization of multi-way switch channels (such as the utility model patent "High-power fuel cell inspection system based on CAN bus technology" with announcement number CN201859204 U), the selection method leading to potential accumulation (such as the utility model patent "High-power fuel cell inspection system based on CAN bus technology" with announcement number CN201859204 U, and the invention patent "A fuel cell stack single-chip voltage inspection system capable of detecting positive and negative voltages" with announcement number CN102288813 B), and the isolation solution fails to completely solve the single-cell contact potential (such as the utility model patent "Single-chip battery inspection system for fuel cells" with announcement number CN212517270U). The lack of a timing coordination mechanism is particularly critical: For example, the technical solution in the invention patent, "A Fuel Cell Stack Cell Voltage Inspection System with Start-Stop Balance Control," with publication number CN108761350B, lacks a synchronized trigger pulse function and a clear timing coordination mechanism for switch gating and data acquisition. This makes it very easy for the transient time during signal establishment to lead to erroneous data acquisition. Furthermore, the systems in this technical solution generally lack a self-calibration function, making it impossible to verify and guarantee the long-term accuracy and stability of the entire scanning measurement system (especially the multiplexer and acquisition channels) under field operating conditions.

[0005] 2. Custom parameter configuration function is missing:

[0006] Different manufacturers have inconsistent parameter definitions for single-cell voltage monitoring (CVM) systems, leading to calibration inaccuracies. Dynamically configuring the signal processing algorithm based on signal characteristics is necessary to ensure that the calibration results are consistent with the physical definition of the measured parameter.

[0007] 3. Bottlenecks in stack impedance measurement technology:

[0008] During the stack impedance measurement process, it is extremely challenging to accurately extract the effective value and phase difference of the small-amplitude excitation AC component and the small-amplitude response AC component against a DC background of tens to hundreds of volts. This is mainly limited by the system's inherent low signal-to-noise ratio and insufficient dynamic range of the analog-to-digital converter, resulting in a significant decrease in the measurement accuracy of the AC signal amplitude and phase difference.

[0009] 4. Lack of two-way metering compatibility:

[0010] Current electrical quantity / energy calibration devices generally use a one-way integration algorithm, which is incompatible with the inverse processes of hydrogen production (electrical energy absorption) and fuel cell power generation (electrical energy release). Testing reversible fuel cell stacks requires switching between different devices, increasing system complexity and metering costs. Summary of the Invention

[0011] The technical problem to be solved by the present invention is to provide an electrical performance calibration device and method that integrates electrolytic hydrogen production and hydrogen fuel cells, so as to solve the problems of poor synchronization, lack of self-calibration, lack of custom parameter configuration function, low impedance measurement accuracy, and incompatibility of two-way measurement when performing electrical performance calibration of electrolytic hydrogen production and hydrogen fuel cells.

[0012] The technical solution of the present invention is achieved as follows: an electrical performance calibration device integrating electrolytic hydrogen production and hydrogen fuel cells, comprising:

[0013] Host computer, first digital sampling voltmeter, second digital sampling voltmeter, synchronous data acquisition card, synchronous inspection switch, current converter, voltage converter, battery stack, programmable power supply, self-calibration module, external calibration signal source;

[0014] The synchronous inspection switch is used to detect the single cell voltage bus of the battery stack and then feed back the voltage to the sampling end of the first digital sampling voltmeter, and the feedback end of the first digital sampling voltmeter is connected to the first input end of the host computer;

[0015] The current converter is used to detect the current loop of the battery stack, convert the detected current signal into an adaptive voltage signal, and then feed it back to the sampling end of the second digital sampling voltmeter and the first acquisition end of the synchronous data acquisition card. The feedback end of the second digital sampling voltmeter is connected to the second input end of the host computer;

[0016] The voltage converter is used to detect the total voltage of the battery stack, convert the detected voltage signal into an adaptive voltage signal, and then feed it back to the second acquisition terminal of the synchronous data acquisition card. The feedback terminal of the synchronous data acquisition card is connected to the third input terminal of the host computer;

[0017] The synchronous inspection switch further generates a synchronous acquisition signal, and sends the synchronous acquisition signal to the trigger end of the first digital sampling voltmeter and the trigger end of the second digital sampling voltmeter;

[0018] The programmable power supply is connected to the power terminal of the battery stack;

[0019] The external calibration signal source is connected to the power supply terminal of the self-calibration module;

[0020] The synchronous inspection switch is also used to switch and detect the single resistor voltage bus of the self-calibration module;

[0021] The host computer comprises a basic voltage parameter calculation unit, a custom voltage parameter calculation unit, an impedance measurement unit and a bidirectional measurement unit.

[0022] Furthermore, the synchronous inspection switch includes a scanning relay group, a polarity relay group, a main controller, a first output bus, and a second output bus;

[0023] The battery stack includes N batteries connected in series, the negative electrodes of the N batteries are respectively connected to the left ends of N leads, and the positive electrode of the Nth battery is connected to the left end of the N+1th lead, where N is an integer greater than 2;

[0024] The scanning relay group includes N+1 channel switching relays, the right ends of the N leads are respectively connected to the static contacts of the N channel switching relays, the right end of the N+1th lead is connected to the static contact of the N+1th channel switching relay, and among the N+1 channel switching relays, the moving contacts of the odd-numbered channel switching relays are connected to the first output bus, and the moving contacts of the even-numbered channel switching relays are connected to the second output bus;

[0025] The polarity relay group includes a first polarity switching relay and a second polarity switching relay, wherein the first static contact of the first polarity switching relay is connected to the first output bus, the second static contact of the first polarity switching relay is connected to the second output bus, the moving contact of the first polarity switching relay is connected to the first sampling terminal of the first digital sampling voltmeter, the first static contact of the second polarity switching relay is connected to the first output bus, the second static contact of the second polarity switching relay is connected to the second output bus, and the moving contact of the second polarity switching relay is connected to the second sampling terminal of the first digital sampling voltmeter;

[0026] The main controller has N+1 channel selection signal pins, which are respectively connected to the coils of N+1 channel switching relays. The main controller also has a first polarity selection signal pin and a second polarity selection signal pin. The first polarity selection signal pin is connected to the coil of the first polarity switching relay, and the second polarity selection signal pin is connected to the coil of the second polarity switching relay. The main controller also has a synchronous acquisition signal pin, which is connected to the trigger end of the first digital sampling voltmeter and the trigger end of the second digital sampling voltmeter.

[0027] Furthermore, the synchronous inspection switch further includes a synchronous pulse output module, and the synchronous acquisition signal pin is connected to the trigger end of the first digital sampling voltmeter and the trigger end of the second digital sampling voltmeter through the synchronous pulse output module.

[0028] Furthermore, the synchronous inspection switch further includes a first cascade port, a second cascade port and a communication module, wherein the first cascade port and the second cascade port are respectively connected to the first cascade signal pin and the second cascade signal pin of the main controller, and the host computer is connected to the main controller through the communication module;

[0029] There are multiple synchronous patrol switches and they are cascaded to form a synchronous patrol switch array. The first cascade port of the synchronous patrol switch at this level is connected to the second cascade port of the synchronous patrol switch at the previous level, and the second cascade port of the synchronous patrol switch at this level is connected to the first cascade port of the synchronous patrol switch at the next level.

[0030] Furthermore, the self-calibration module includes N resistors connected in series, a single-gain precision buffer is connected in series at both ends of each resistor, the power supply terminals of the N resistors connected in series are connected to the external calibration signal source, and the left ends of the N leads are respectively connected to the N single-gain precision buffers.

[0031] A method for calibrating the electrical performance of a fusion electrolytic hydrogen production and hydrogen fuel cell, using the electrical performance calibration device, includes self-calibration:

[0032] First, a standard voltage source is used as an external calibration signal source, combined with a self-calibration module to apply standard DC voltage signals of equal value to the N channels of the synchronous inspection switch.

[0033] Secondly, a standard square wave signal source is used as an external calibration signal source, combined with a self-calibration module to apply standard square wave signals of equal value to the N channels of the synchronous inspection switch;

[0034] Finally, a standard signal source is used as an external calibration signal source to generate a signal simulating the actual fluctuating working condition and input it into the self-calibration module.

[0035] Furthermore, it also includes operation timing coordination:

[0036] First, the host computer sends a channel selection command to the synchronous inspection switch;

[0037] Secondly, the synchronous inspection switch responds to the command and switches to the target channel;

[0038] Third, after the channel is stable, the synchronous inspection switch outputs a level trigger signal to the first digital sampling voltmeter;

[0039] Fourth, the first digital sampling voltmeter receives the trigger signal and starts ADC synchronous sampling;

[0040] Finally, the sampled data is cached and read by the host computer to complete the data processing.

[0041] Furthermore, it also includes custom voltage parameter measurement algorithms:

[0042] First, initialization and signal acquisition: start raw signal acquisition according to the preset sampling configuration;

[0043] Secondly, configurable filtering: dynamically determine whether to enable filtering, and if you choose to apply the filtering algorithm, perform real-time noise suppression;

[0044] Third, instantaneous data acquisition and storage: obtain the instantaneous sampling value of the current channel and store it in the buffer area;

[0045] Fourth, closed-loop verification of data validity: Threshold detection is implemented based on the 3σ criterion to verify whether the data conforms to the statistical distribution law; if the data is invalid, it automatically returns to the signal acquisition step to obtain it again;

[0046] Fifth, parameter algorithm adaptive selection: determines whether to enable the custom algorithm. If the parameter algorithm is selected, the user-defined parameterized calculation model is entered; otherwise, the basic voltage parameters are calculated according to the preset algorithm.

[0047] Finally, data encapsulation and output: encapsulate the calculation results and report them through the communication interface.

[0048] Furthermore, it also includes stack impedance testing:

[0049] First, the system is initialized: the data acquisition card is connected to the programmable power supply, and historical status data is cleared;

[0050] Secondly, parameter configuration: set the sampling frequency / range of the synchronous data acquisition card, configure the power supply output DC bias voltage and modulated AC signal parameters;

[0051] Third, signal acquisition: synchronously collect the original signals of the stack terminal voltage and electrolysis current;

[0052] Fourth, low-pass filtering: filter out high-frequency ripple noise through a windowed FIR digital filter;

[0053] Fifth, AC coupling separation: Calculate the DC average value of the filtered voltage signal and the DC average value of the current signal; subtract the DC component point by point to extract the pure AC modulation voltage and response current;

[0054] Sixth, spectrum analysis and impedance calculation: Perform FFT on the AC modulated voltage and response current to obtain the voltage fundamental effective value and initial phase at the test frequency; the current fundamental effective value and initial phase; the phase difference between the voltage fundamental initial phase and the current fundamental initial phase; and calculate the stack impedance;

[0055] Finally, data recording: the impedance spectrum data is stored and the process terminates.

[0056] Furthermore, it also includes two-way measurement:

[0057] First, the basic parameters for stack charge and energy calibration are the instantaneous sampling values ​​of the stack total voltage and total current. The synchronous data acquisition card continuously collects voltage and current signals.

[0058] Secondly, after eliminating noise interference through digital filtering, a pre-processed discrete instantaneous sampling sequence is generated and stored in the data buffer queue in real time;

[0059] Third, the interception time length is set based on the refresh cycle of the measured parameter. The number of samples is measured by the time length and the sampling rate. Multiple consecutive samples are extracted from the buffer to form a complete sampling cycle.

[0060] Finally, the stack charge and energy are the integrals of instantaneous current and instantaneous power over time, respectively.

[0061] Compared with the background technology, the present invention has the following advantages:

[0062] 1. It has a synchronous trigger and self-calibration coordination mechanism. It outputs precise trigger pulses through the synchronous inspection switch to achieve strict timing coordination between channel switching and data acquisition, eliminating the signal desynchronization problem caused by switching delay; the integrated self-calibration module simulates the static and dynamic working conditions of the fuel cell stack, realizes the self-verification function of the device, and makes the DC voltage measurement error ≤±0.01% (full scale). The consistency between channels is further improved, and the long-term measurement reliability is significantly improved.

[0063] 2. It has custom parameter configuration function and flexible adaptability of the parameter customization engine. Based on the pre-processing process of sliding average filtering (window width adaptation) and 3σ threshold detection, it supports five voltage characterization algorithms: instantaneous value, arithmetic mean, root mean square value, range, and standard deviation, and a configurable data window. It solves the calibration inaccuracy problem caused by inconsistent parameter definitions of single-cell voltage monitoring systems (CVM) from different manufacturers; it dynamically selects the processing mode based on signal characteristics (directly calculate the mean / root mean square value for periodic signals, and dynamically calculate the mean / root mean square value for non-periodic signals based on the integration time), so that the calibration results are consistent with the physical quantity of the measured parameters.

[0064] 3. It has the characteristics of high impedance measurement accuracy and software AC coupling impedance measurement technology. It adopts high-precision digital sampling combined with software AC coupling (dynamic separation of DC mean and AC components) and FFT spectrum analysis, which can overcome the difficulty of measuring the effective value and phase of small AC signals under a large DC background.

[0065] 4. It has the characteristics of bidirectional measurement compatibility, bidirectional measurement of electricity and electric energy, through real-time generation of positive / negative current arrays and power arrays, combined with adaptive integration algorithms (trapezoidal / Simpson / Bode law) to independently accumulate the energy of electrolysis absorption and power generation release processes, to achieve bidirectional electricity / electric energy measurement, compatible with three working modes: electrolyzer, fuel cell and reversible battery stack. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0067] Figure 1 This is a hardware architecture diagram of an electrical performance calibration device that integrates electrolytic hydrogen production and hydrogen fuel cells in the present invention.

[0068] Figure 2 It is a functional block diagram of the integrated electrolysis hydrogen production and hydrogen fuel cell electrical performance calibration device of the present invention.

[0069] Figure 3 It is a flow chart of the single cell voltage scanning measurement of the present invention.

[0070] Figure 4 It is a flow chart of the custom parameter measurement algorithm of the present invention.

[0071] Figure 5 This is a configuration diagram of the stack impedance equipment of the present invention.

[0072] Figure 6 This is a flow chart of the stack impedance test of the present invention.

[0073] Figure 7 It is a functional flow chart of the polarization curve of the present invention.

[0074] Figure 8This is a data processing flow chart of the electrical quantity and energy calibration process of the present invention.

[0075] Figure 9 It is a structural block diagram of the twenty-four-way synchronous inspection switch unit in the present invention.

[0076] Figure 10 This is a structural block diagram of the twenty-four-way synchronous inspection switch array in the present invention.

[0077] Figure 11 It is a structural diagram of the synchronous inspection switch in the present invention.

[0078] Figure 12 This is a wiring diagram of the self-calibration of the twenty-four-way synchronous inspection switch in the present invention.

[0079] Figure 13 It is a schematic diagram of the operation sequence of the synchronous inspection switch in the present invention. DETAILED DESCRIPTION

[0080] See Figures 1 to 13 , an electrical performance calibration device integrating electrolytic hydrogen production and hydrogen fuel cells, comprising:

[0081] Host computer, first digital sampling voltmeter, second digital sampling voltmeter, synchronous data acquisition card, synchronous inspection switch, current converter, voltage converter, battery stack, programmable power supply, self-calibration module, external calibration signal source;

[0082] The synchronous inspection switch is used to detect the single cell voltage bus of the battery stack and then feed back the voltage to the sampling end of the first digital sampling voltmeter, and the feedback end of the first digital sampling voltmeter is connected to the first input end of the host computer;

[0083] The current converter is used to detect the current loop of the battery stack, convert the detected current signal into an adaptive voltage signal, and then feed it back to the sampling end of the second digital sampling voltmeter and the first acquisition end of the synchronous data acquisition card. The feedback end of the second digital sampling voltmeter is connected to the second input end of the host computer;

[0084] The voltage converter is used to detect the total voltage of the battery stack, convert the detected voltage signal into an adaptive voltage signal, and then feed it back to the second acquisition terminal of the synchronous data acquisition card. The feedback terminal of the synchronous data acquisition card is connected to the third input terminal of the host computer;

[0085] The synchronous inspection switch further generates a synchronous acquisition signal, and sends the synchronous acquisition signal to the trigger end of the first digital sampling voltmeter and the trigger end of the second digital sampling voltmeter;

[0086] The programmable power supply is connected to the power terminal of the battery stack;

[0087] The external calibration signal source is connected to the power supply terminal of the self-calibration module;

[0088] The synchronous inspection switch is also used to switch and detect the single resistor voltage bus of the self-calibration module;

[0089] The host computer comprises a basic voltage parameter calculation unit, a custom voltage parameter calculation unit, an impedance measurement unit and a bidirectional measurement unit.

[0090] In the present invention, the host computer not only receives the battery stack voltage information detected by the synchronous patrol switch, but also receives the current information of the current loop of the battery stack and the total voltage information of the battery stack. The software system can dynamically load different measurement algorithms and provide configuration, monitoring and result visualization functions, ultimately forming functional modules such as single-cell voltage patrol calibration, battery stack total voltage and total current calibration, single-cell / battery stack polarization curve parameter calibration, battery stack charge and energy calibration, battery stack impedance calibration, and battery stack other parameter calibration.

[0091] When calibrating the stack, the leads of the synchronous inspection switch are connected to the single-cell voltage bus of the stack; when performing self-calibration, the leads of the synchronous inspection switch are connected to the single-resistance voltage bus of the self-calibration module.

[0092] The basic voltage parameter calculation unit of the host computer is used to calculate the voltage of each battery fed back by the synchronous inspection switch, that is, the basic voltage parameter.

[0093] The custom voltage parameter calculation unit of the host computer is used to calculate the custom voltage parameters based on the basic voltage parameters and the actual application scenarios of the parameters. The custom voltage parameters include but are not limited to: the instantaneous sampling value of the single cell voltage, the root mean square value of the specified time interval, the average value of the single cell voltage, the range of the single cell voltage, and the standard deviation of the single cell voltage.

[0094] The impedance measurement unit of the host computer is used to calculate the impedance of the fuel cell stack, superimpose a small-amplitude AC excitation voltage of a specific scanning frequency on the large-amplitude DC voltage output by the programmable power supply, and input the superimposed composite signal into the fuel cell stack to be tested.

[0095] The host computer's bidirectional metering unit identifies current direction in real time and independently accumulates positive and negative charge, power, and energy. It's compatible with testing hydrogen electrolysis stacks, fuel cell stacks, and reversible stacks.

[0096] Combine Figure 1 , the first digital sampling voltmeter is Figure 1 The collector (DVM1) in the second digital sampling voltmeter is Figure 1The first digital sampling voltmeter, the second digital sampling voltmeter, and the synchronous data acquisition card are connected to the host PC through the corresponding USB signal line; multiple synchronous inspection switches are cascaded to form a synchronous inspection switch array; the current converter is Figure 1 The I / V converter in Figure 1 V / V converter in the programmable power supply corresponds to Figure 1 Electrolytic power supply in; external calibration signal source and self-calibration module are combined and output Figure 1 The external calibration signal in is given to the synchronous patrol switch array.

[0097] Further, combined with Figures 9 to 11 , Figure 9 It is a structural block diagram of the twenty-four-way synchronous inspection switch unit in the present invention. Figure 10 This is a structural block diagram of the twenty-four-way synchronous inspection switch array in the present invention. Figure 11 This is a structural diagram of the synchronous inspection switch of the present invention. The synchronous inspection switch includes a scanning relay group, a polarity relay group, a main controller, a first output bus, and a second output bus;

[0098] The battery stack includes N batteries connected in series, the negative electrodes of the N batteries are respectively connected to the left ends of N leads, the negative electrode of the Nth battery is connected to the left end of the Nth lead, and the positive electrode of the Nth battery is connected to the left end of the N+1th lead, where N is an integer greater than or equal to 2;

[0099] The scanning relay group includes N+1 channel switching relays, the right ends of the N leads are respectively connected to the static contacts of the N channel switching relays, the right end of the Nth lead is connected to the static contact of the Nth channel switching relay, and the right end of the N+1th lead is connected to the static contact of the N+1th channel switching relay. Among the N+1 channel switching relays, the moving contacts of the odd-numbered channel switching relays are connected to the first output bus, and the moving contacts of the even-numbered channel switching relays are connected to the second output bus.

[0100] The polarity relay group includes a first polarity switching relay and a second polarity switching relay, wherein the first static contact of the first polarity switching relay is connected to the first output bus, the second static contact of the first polarity switching relay is connected to the second output bus, the moving contact of the first polarity switching relay is connected to the first sampling terminal of the first digital sampling voltmeter, the first static contact of the second polarity switching relay is connected to the first output bus, the second static contact of the second polarity switching relay is connected to the second output bus, and the moving contact of the second polarity switching relay is connected to the second sampling terminal of the first digital sampling voltmeter;

[0101] The main controller has N+1 channel selection signal pins, which are respectively connected to the coils of N+1 channel switching relays, and the N+1th channel selection signal pin is connected to the coil of the N+1th channel switching relay. The main controller also has a first polarity selection signal pin and a second polarity selection signal pin, the first polarity selection signal pin is connected to the coil of the first polarity switching relay, and the second polarity selection signal pin is connected to the coil of the second polarity switching relay. The main controller also has a synchronous acquisition signal pin, which is connected to the trigger end of the first digital sampling voltmeter and the trigger end of the second digital sampling voltmeter.

[0102] As can be seen from the above description, the main controller sends a channel selection signal to the scanning relay group, causing the two adjacent channel switching relays to turn on and off in sequence for inspection. The main controller also sends a polarity selection signal to the polarity relay group, causing the first polarity switching relay and the second polarity switching relay to reverse polarity each time, thereby maintaining the first sampling terminal of the first digital sampling voltmeter connected to the positive terminal of a single battery and the second sampling terminal connected to the negative terminal of a single battery, and sequentially selecting the batteries in the battery stack for voltage detection. After the channel switching relay selects a battery, after a specified delay time, the main controller sends a signal to trigger the data acquisition device to perform data acquisition work, ensuring that data acquisition and detection are performed when the channel switching relay contacts are closed and stable, thereby improving the accuracy of voltage detection.

[0103] Combine Figure 11 , N batteries connected in series are Figure 11 C1 to Cn in the N+1 channel switching relays are Figure 11 S1 to Sn+1 in the first polarity switching relay is Figure 11 K1 in the second pole switching relay is Figure 11 K2 in; the first output bus is Figure 11 P1; the second output bus is Figure 11 P2; the first digital sampling voltmeter is Figure 11 The first sampling terminal of the first digital sampling voltmeter is Figure 11 H in the first digital sampling voltmeter; the second sampling terminal of the first digital sampling voltmeter is Figure 11 L in the middle; synchronous acquisition signal pin output Figure 11 The TTL pulse in the

[0104] For example, a battery stack includes 24 batteries connected in series. The negative terminal of the first battery is connected to the left end of the first lead, the negative terminal of the 24th battery is connected to the left end of the 24th lead, and the positive terminal of the 24th battery is connected to the left end of the 25th lead. There are 25 channel switching relays, of which the moving contacts of the odd-numbered channel switching relays (1, 3, 5, 25) are connected to the first output bus, and the moving contacts of the even-numbered channel switching relays (2, 4, 6, 24) are connected to the second output bus. The main controller has 25 channel selection signal pins. When the first channel switching relay and the second channel switching relay select the first battery, the first polarity switching relay selects the first output bus, and the second polarity switching relay selects the second output bus; when the second channel switching relay and the third channel switching relay select the second battery, the first polarity switching relay selects the second output bus, and the second polarity switching relay selects the first output bus; when the third channel switching relay and the fourth channel switching relay select the third battery, the first polarity switching relay selects the first output bus, and the second polarity switching relay selects the second output bus; when the fourth channel switching relay and the fifth channel switching relay select the fourth battery, the first polarity switching relay selects the second output bus, and the second polarity switching relay selects the first output bus; and so on, to complete the inspection and polarity reversal.

[0105] Further, combined with Figure 9 The synchronous inspection switch also includes a relay driving module, and the N+1th channel selection signal pin is connected to the coil of the N+1th channel switching relay through the N+1th relay driving module.

[0106] From this description, it can be seen that the relay driving module is provided to provide sufficient electrical signals to enable the channel switching relay to perform switching actions more stably.

[0107] Further, combined with Figure 9 The synchronous inspection switch also includes a status monitoring module, and the N+1th relay driving module is also connected to the N+1th status monitoring module.

[0108] From this description, it can be seen that the state monitoring module can more clearly understand whether the corresponding channel switching relay is in the on state or the off state.

[0109] Further, combined with Figure 9 The synchronous inspection switch also includes a synchronous pulse output module, and the synchronous acquisition signal pin is connected to the trigger end of the first digital sampling voltmeter and the trigger end of the second digital sampling voltmeter through the synchronous pulse output module.

[0110] From this description, it can be seen that the synchronous pulse output module is used to strengthen the synchronous acquisition signal sent by the main controller, which helps to stably trigger the acquisition work of the data collector.

[0111] Further, combined with Figure 9 , the synchronous inspection switch further includes a first cascade port, a second cascade port and a communication module, the first cascade port and the second cascade port are respectively connected to the first cascade signal pin and the second cascade signal pin of the main controller, and the host computer is connected to the main controller through the communication module;

[0112] Combine Figure 10 There are multiple synchronous patrol switches and they are cascaded to form a voltage patrol array. The first cascade port of the synchronous patrol switch at this level is connected to the second cascade port of the synchronous patrol switch at the previous level, and the second cascade port of the synchronous patrol switch at this level is connected to the first cascade port of the synchronous patrol switch at the next level.

[0113] The first cascade port is Figure 9 and Figure 10 cascade port I in the cascade port; the second cascade port is Figure 9 and Figure 10 Cascade port II in.

[0114] From this description, it can be seen that the synchronous inspection switch of the present invention has a cascade function. Multiple synchronous inspection switches are cascaded in sequence to inspect more battery stacks with more batteries connected in series. The host computer controls the synchronous inspection switches of each level to work in an orderly manner with the help of the communication module.

[0115] Further, combined with Figure 9 The synchronous inspection switch also includes a power module, a key module and a display module. The power module is connected to the power signal pin of the main controller, the key module is connected to the key signal pin of the main controller, and the display module is connected to the display signal pin of the main controller.

[0116] From this description, we can see that the power module provides power, the button module is used to input setting parameters to the main controller, and the display module is used for the main controller to output the operation results to the outside, so that the staff can understand the current status of the synchronous inspection switch.

[0117] Further, combined with Figure 12 , Figure 12 This is a wiring diagram for the self-calibration of a 24-way synchronous inspection switch according to the present invention. The self-calibration module includes N series-connected resistors, each with a single-gain precision buffer connected in series at both ends. The power supply terminals of the N series-connected resistors are connected to the external calibration signal source, and the left ends of the N leads are each connected to N single-gain precision buffers.

[0118] From this description, it can be seen that the self-calibration module simulates the battery stack and is used to calibrate the operating status of the synchronous inspection switch, which helps to debug the synchronous inspection switch and improve the accuracy of subsequent actual battery stack detection.

[0119] The N batteries connected in series are Figure 12 V1 to Vn in the figure; N single-gain precision buffers are Figure 12 U1 to Un in.

[0120] The synchronous inspection switch of the present invention can be used for voltage inspection of various types of battery stacks (such as fuel cell stacks, water electrolysis hydrogen production electrolyzer stacks or single cells of battery modules (hereinafter referred to as "single cells"). The synchronous inspection switch is designed as a unit in a modular manner, and each unit can scan 24 single cells, such as Figure 9 The block diagram of the 24-way synchronous inspection switch unit in the present invention is shown in Figure 1. It consists of an MCU, power module, communication module, switch scanning module, relay drive and status monitoring module, synchronous pulse output module, self-calibration module, and peripheral modules (keys, display). The present invention uses a high-speed, high-precision digital sampling voltmeter (similar to a high-precision ADC converter). Units are cascaded to expand the number of scanning channels to accommodate different sizes of battery stacks. Theoretically, unlimited expansion is possible, such as Figure 10 shown.

[0121] The synchronous inspection switch has the following three characteristics:

[0122] (1) Scanning switch module (S1, S2....S25; ​​K1, K2)

[0123] The scanning switch module consists of 25 channel switching relays and two polarity switching relays. The 25 channel switching relays are used to switch the channels of the 24 single cells. Each single cell is connected to two channel switching relays. Each channel switching relay is connected to the first output bus P1 and the second output bus P2 in the order of the connected single cells. The two polarity switching relays are used to reverse the polarity (such as Figure 11 The design of a two-stage switch structure can reduce the number of measurement leads from 2n to n+1, and at the same time enable the scanning switch module to adjust the polarity between channels and within the channel itself.

[0124] The main controller will send commands based on the working conditions. The commands are controlled by two control codes, one for "channel selection" and the other for "polarity selection." When inspecting by channel number, the polarity of the first output bus P1 alternates between positive and negative, and the polarity of the second output bus P2 alternates between negative and positive. The polarity of the first output bus P1 and the second output bus P2 can be changed by the first polarity switching relay K1 and the second polarity switching relay K2, so that the output polarity of the final bus remains unchanged. On the other hand, the voltage amplitude of a single cell is generally low. At this time, the influence of the comprehensive parasitic potential introduced by temperature changes in the connections between components such as measuring leads, relays, and measuring meters cannot be ignored. The contact thermal potential is measured using the "polarity reversal method," and the measurement results are corrected to deduct the cumulative contact potential caused by connecting multiple single cells in series.

[0125] (2) Self-calibration module

[0126] The self-calibration module consists of 24 precision alloy foil resistors with the same resistance value, forming a 24-way "1:1...:1" resistor divider network. A single-gain precision buffer is connected in series at both ends of each resistor, so that the differential voltage Vi (i=1, 2, ....24) across each resistor is equal to the input voltage Ui (i=1, 2, ....24) of the scanning switch module. This not only simulates the 24 single cell voltages (which can be regarded as standard voltages here), but also transforms the output impedance of the divider network, thereby isolating the impact of the measurement circuit on the load side. Figure 12 The self-calibration module can be connected to an external programmable signal source as a calibration signal input to simulate single-cell voltage signals with various changing characteristics, which is used to verify the measurement capability of the scanning measurement system under different battery stack operating conditions.

[0127] (3) Synchronous signal output module

[0128] The present invention adopts a structure of a high-precision single collector combined with a multi-channel scanning switch. By adding a multi-channel scanning switch, the number of collection channels is expanded, which can better adapt to various sizes of battery stacks. However, when conducting a single-cell voltage inspection of the battery stack through a multi-way switching switch, a detail that is easily overlooked is the operation coordination of the channel switch and the data collector connected to the back end, and a handshake working mechanism should be established between the two. The transition time from the switch receiving the closing command to the complete closure is defined as the "signal establishment time". After the delay of the signal establishment time, the switch generates a synchronous pulse output signal as a trigger signal for the data collector to start sampling. In addition, in order to ensure the safety of the scanning measurement, only one single cell is allowed to be connected at any time, and the "break before make" principle is implemented. After completing the collection and reading, the data collector also gives a status mark of "measurement completed" to notify the switch to perform the disconnection operation.

[0129] like Figure 13 As shown, Figure 13 This is a schematic diagram of the synchronous inspection switch operation sequence in the present invention. When the host computer sends a switch-close command, due to the relay's switching time, there is a delay t1 between the switch turning on and the output of the TTL pulse. When using timed sampling mode, the first sample is taken after a trigger delay time. After the first sample begins, the second sample begins after the sampling interval, and so on. There is a trigger delay t2 between the rising edge (or falling edge, depending on the trigger edge polarity setting) of the TTL pulse and the first sample. Each channel samples n samples at equal intervals, and the total sampling time should be included in the on-time of each channel. t1 is the relay's operating time. To ensure that each sample is only taken for one channel, the next channel must be sampled after the previous channel is disconnected. Therefore, the relay's operating time should be considered 2t1, approximately 8 ms. The trigger delay t2 is related to the set integration time. When the integration time is set to 20 ms (equivalent to NPLC = 1), the trigger delay is 160 μs. If the number of channel samples is n, the time required to complete a channel sample is n times the integration period. To successfully complete independent and complete sampling of each channel, the operating timing of each component should be fully analyzed. The sampling process of each channel should be included in the "on-time" of the switch and the "time interval" of sampling, and the characteristics of the measured signal need to be considered.

[0130] Main controller: The main controller (MCU) adopts STM32F103RBT6, which is based on the ARM Cortex-M3 core, has a maximum operating frequency of 72MHz, provides a processing power of 90 DMIPS (million instructions per second), supports single-cycle multiplication and hardware division operations, adopts a 32-bit RISC architecture, and has a streamlined and efficient instruction set, suitable for real-time control and complex algorithm processing.

[0131] The power module converts the input power voltage from 9-24V to 5V and supports USB input, providing operating power and control voltage for the microcontroller and relays. The power module also incorporates the TPS5430 power conversion chip, which uses a fixed-frequency (500kHz) control mode to support high-precision output regulation. The input voltage range is 5.5V to 36V, and the output voltage is adjustable from 1.221V to 32V with an accuracy of ±1.5%. The conversion efficiency reaches up to 95%, and the continuous output current can reach 3A, meeting high load requirements. This module is responsible for powering the relay driver module.

[0132] Communication Module: Communication between the synchronous inspection switch and the host computer is implemented via a serial port, using the FT232R serial port conversion chip. The FT232R, through its built-in USB protocol engine and UART controller, converts the USB interface into a standard RS-232 / RS-422 / RS-485 serial communication interface, enabling interaction between the PC and the serial device (the scan switch module). The FT232R supports both asynchronous communication mode (character transmission) and synchronous FIFO mode (high-speed data block transfer). It is compatible with serial protocols such as RS-232, RS-422, and RS-485, supporting baud rates up to 3 Mbps. It can be directly connected to a microcontroller's UART pins (0V / 3.3V or 5V logic), generating TTL levels. In the scan switch module, USB1 port is responsible for communication between the host computer and the scan switch module. The communication part of the scanning switch module also includes the cascade between different modules. Through two USB-TYPE-C interface terminals, the USB2 port of the rear module is connected to the USB3 port of the front module, which is used to provide communication and power supply between the microcontroller of the cascade module and the host computer.

[0133] The switch scanning module consists of two parts: an input and an output. Both utilize TX2-5V electromagnetic relays. The input section uses 25 relays to form a scanning relay group, while the output section uses two relays to form a polarity relay group. The TX2-5V operates based on the principle of electromagnetic induction. By energizing the coil, a magnetic field is generated, which attracts the armature, closing or opening the contacts, thereby controlling the circuit's on / off state.

[0134] Relay driver and status monitoring module: The scanning relay module uses the ULN2803A chip for relay driver and status monitoring, with relay status indicated by an LED. The polarity reversal relay module uses the ULN2001D chip, with its input directly connected to the MCU's GPIO pins. Thanks to the chip's built-in 2.7kΩ base resistor and 4.7kΩ pull-down resistor, it can be directly connected to TTL / CMOS logic circuits.

[0135] The open collector output characteristic of ULN2001D enables it to directly drive the relay coil on and off, and the relay status monitoring also uses LED indication.

[0136] Synchronous pulse output module: Model TLP521 is a controllable optocoupler device that achieves electrical isolation between the input and output ends through the coupling of a gallium arsenide infrared light-emitting diode (LED) and a phototransistor, while also completing the conversion of electrical signals to optical signals and back to electrical signals.

[0137] Self-calibration module: The self-calibration module consists of 24 precision alloy foil resistors of the same resistance value, forming a 24-way "1:1...:1" resistor divider network. A single-gain precision buffer is connected in series at both ends of each resistor. This module provides self-calibration capabilities, allowing for periodic calibration of the scanning system, in-use inspection, and in-application correction. Combined with standard dynamic signals, it verifies the dynamic measurement capabilities of the scanning system.

[0138] The present invention provides an electrical performance calibration device integrating electrolytic hydrogen production and hydrogen fuel cells, which is composed of the following core hardware components and software systems: Figure 1 The core hardware components include the host computer, the first digital sampling voltmeter (DVM1) and the second digital sampling voltmeter (DVM2), a synchronous data acquisition card, a synchronous inspection switch array, a current converter (I / V converter), a voltage converter (V / V converter), an electrolytic power supply (if necessary), and an electronic load (if necessary) (see the hardware architecture for details). Figure 1 ).

[0139] The first digital sampling voltmeter (DVM1) and the second digital sampling voltmeter (DVM2) perform intermittent sampling, while the synchronous data acquisition card performs continuous sampling. The electrolysis power supply is a DC power supply with modulated AC, capable of superimposing a small-amplitude AC signal on the DC power supply for stack impedance sweep frequency measurement. The synchronous inspection switch array utilizes a cascaded channel expansion architecture, supporting independent channel gating (sequential polling or specified gating), adhering to the "single gating" and "break-before-make" principles. It can be dynamically expanded through host computer control to accommodate different stack sizes. The synchronous inspection switch array features a synchronous pulse output function to coordinate switching and acquisition timing. It also integrates a self-calibration module to verify channel consistency and simulate operating condition signal testing system performance.

[0140] The software system is developed based on the LabVIEW platform, adopting a layered architecture including a hardware communication layer, an algorithm logic layer, and a human-computer interaction layer, and using a parallel task scheduling mechanism. This mechanism realizes the automation of the entire process of hardware control, synchronous triggering, data acquisition, signal analysis, and parameter calculation, among which data acquisition supports high-speed pipeline processing. The software system can dynamically load different measurement algorithms and provide configuration, monitoring, and result visualization functions. Ultimately, functional modules such as single-cell voltage inspection calibration, stack total voltage and total current calibration, single-cell / stack polarization curve parameter calibration, stack charge and energy calibration, stack impedance calibration, and stack other parameter calibration are formed. Its functional block diagram is as follows: Figure 2 shown. Figure 2 It is a functional block diagram of the integrated electrolysis hydrogen production and hydrogen fuel cell electrical performance calibration device of the present invention.

[0141] The present invention provides a method for calibrating the electrical performance of a fusion electrolytic hydrogen production and a hydrogen fuel cell, comprising the following:

[0142] (1) Self-calibration capability: To meet the measurement requirements of the calibration device under the actual operating conditions of the fuel cell stack, the device of the present invention needs to have self-calibration capability. This is achieved by integrating a self-calibration module into the synchronous inspection switch array:

[0143] First, using a standard voltage source as an external calibration signal source, combined with a self-calibration module, we applied standard DC voltage signals of equal value to the N channels of the synchronous inspection switch. This verified the voltage measurement accuracy and inter-channel consistency of each channel under static conditions. Second, using a standard square wave signal source as an external calibration signal source, combined with a self-calibration module, we applied standard square wave signals of equal value to the N channels of the synchronous inspection switch. By testing the calibration device's response to the square wave signal, we verified its dynamic measurement capability under voltage fluctuation conditions.

[0144] Finally, a standard signal source is used as an external calibration signal source to generate a signal that simulates actual fluctuating working conditions and inputs it into the self-calibration module to verify its ability to measure various user-defined parameters.

[0145] (2) Operation timing coordination method: When performing a single-cell voltage inspection task, a collaborative working mechanism for channel switching and data acquisition needs to be established. This mechanism involves key links such as hardware timing control, signal synchronization, and data flow management to ensure the accuracy and real-time performance of voltage measurement. Its core workflow is:

[0146] First, the master controller sends a channel selection command to the synchronous inspection switch;

[0147] Second, the switch array responds to the command and switches to the target channel;

[0148] Third, after the channel is stable, the synchronous inspection switch outputs a level trigger signal to the first digital sampling voltmeter;

[0149] Fourth, the first digital sampling voltmeter receives the trigger signal and starts ADC synchronous sampling;

[0150] Finally, the sampled data is cached (such as FIFO) and then read by the host computer to complete the data processing.

[0151] Considering that factors such as switch action delay, signal establishment time and switch bounce noise can affect signal stability, this system adopts a master-slave control architecture to ensure that valid voltage signals are collected in a stable state: the master controller is responsible for generating channel switching timing instructions and 2C and other interfaces drive the synchronous inspection switch; as a slave device, the synchronous inspection switch actively sends an acquisition trigger signal after the target channel reaches a stable state; the first digital sampling voltmeter responds to this trigger signal and immediately starts the acquisition operation, and efficiently transmits the sampled data to the host computer through the DMA channel.

[0152] The core of this coordination mechanism is to achieve accurate hardware-level timing matching between the channel switching stability of the synchronous inspection switch and the start of sampling by the digital sampling voltmeter. The complete operation process is as follows: Figure 3 shown. Figure 3 It is a flow chart of the single cell voltage scanning measurement of the present invention.

[0153] (3) Design of custom voltage parameter measurement algorithm: Based on the collected basic data and combined with the actual application scenarios of the parameters, the present invention provides a configurable measurement algorithm system. The algorithm supports on-demand calculation of multiple types of parameters (including but not limited to: single cell voltage instantaneous sampling value, root mean square value of specified time interval, single cell voltage average value, single cell voltage range, single cell voltage standard deviation). The algorithm flow chart is as follows: Figure 4 As shown, Figure 4 This is a flow chart of the custom parameter measurement algorithm of the present invention. It corresponds to the working mode of the custom voltage parameter calculation unit. Its core steps and dynamic control logic are as follows:

[0154] ① Initialization and signal acquisition: Start raw signal acquisition according to the preset sampling configuration;

[0155] ②Configurable filtering: Dynamically determine whether to enable filtering. If a filtering algorithm (such as a sliding average filter) is selected, real-time noise suppression is performed.

[0156] ③ Instantaneous data acquisition and storage: obtain the instantaneous sampling value of the current channel and store it in the buffer area;

[0157] ④ Closed-loop verification of data validity: Implement threshold detection based on the 3σ criterion to verify whether the data conforms to the statistical distribution law; if the data is invalid, it will automatically return to the signal acquisition step to obtain it again;

[0158] ⑤ Parameter algorithm adaptive selection: Determine whether to enable the custom algorithm. If the parameter algorithm is selected, the user-defined parameterized calculation model (such as range / standard deviation, etc.) will be entered. Otherwise, the basic voltage parameters will be calculated according to the preset algorithm.

[0159] ⑥Data encapsulation and output: encapsulate the calculation results and report them through the communication interface.

[0160] (4) Stack impedance test method: Stack impedance test is carried out according to Figure 5 As shown; Figure 5This is a diagram of the stack impedance equipment configuration of the present invention. A small-amplitude AC voltage of the test frequency is modulated at the DC power input of the electrolytic cell stack, and a non-intrusive current sensor (such as a zero-flux closed-loop sensor) is connected to the electrolytic current loop to monitor the current in the electrolytic circuit. This corresponds to the operating mode of the impedance measurement unit. The stack impedance test process is performed as follows:

[0161] ① System initialization: Synchronize the data acquisition card and programmable power supply to clear historical status data;

[0162] ②Parameter configuration: Set the sampling frequency / range of the synchronous data acquisition card, configure the power supply output DC bias voltage and modulated AC signal parameters;

[0163] ③Signal acquisition: synchronously collect the original signals of the stack terminal voltage and electrolysis current (including significant DC components and weak AC modulation components);

[0164] ④ Low-pass filtering: Filter out high-frequency ripple noise through a windowed FIR digital filter;

[0165] ⑤AC coupling separation: Calculate the DC average value of the filtered voltage signal and the DC average value of the current signal; subtract the DC component point by point to extract the pure AC modulation voltage and response current;

[0166] ⑥ Spectrum analysis and impedance calculation: Perform FFT on the AC modulated voltage and response current to obtain the voltage fundamental RMS value at the test frequency and initial phase ; Current fundamental effective value and initial phase Phase difference ; Calculate the stack impedance according to the formula: (1)

[0167] ⑦Data recording: store impedance spectrum data and the process terminates.

[0168] See the complete process Figure 6 , Figure 6 This is a flow chart of the stack impedance test of the present invention.

[0169] To achieve these high-precision measurements, the synchronous data logger must meet the following requirements: Its ADC resolution and dynamic range at the sampling frequency must be sufficient to accurately capture both high-amplitude DC components and low-amplitude AC components. If the signal to be measured contains high-frequency noise, such as DC output ripple, an anti-aliasing filter should be placed at the input of the data logger, or a data logger with an anti-aliasing filter should be used directly to prevent high-frequency noise from aliasing into the valid frequency band.

[0170] DC power supplies inherently have output ripple, and this ripple has a wide frequency band (e.g., 10 Hz to 20 MHz). Direct analysis and calculation will interfere with the modulated voltage signal and introduce additional errors. The data logger's pre-antialiasing filter cannot suppress ripple noise within 0.453 fs (sampling frequency), so software low-pass filtering is required. However, software low-pass filtering introduces phase lag, reducing sensitivity, necessitating filter group delay correction.

[0171] Software low-pass filtering method:

[0172] ① Set the upper and lower limits of the frequency according to the frequency range of the signal to be measured (here mainly considering the impedance measurement scanning frequency).

[0173] ② Based on signal analysis and measurement accuracy requirements, set the passband edge frequency (designed to be the lower limit of the modulation wave frequency), stopband edge frequency (designed to be the upper limit of the modulation wave frequency), passband ripple (0.1dB), and stopband attenuation (60dB) parameters. Verify the rationality of the parameter settings.

[0174] ③ Set the downsampling coefficient and downsampling frequency according to the stopband edge frequency and the highest frequency of the modulation signal.

[0175] ④ Design a windowed low-pass filter and calculate the low-pass filter coefficient, band-pass filter coefficient and filter group delay.

[0176] ⑤ Perform low-pass filtering, downsampling and band-pass filtering on the collected waveform.

[0177] ⑥ Perform phase lag correction on the filtered signal according to the filter group delay.

[0178] (5) Two-way measurement method:

[0179] First, the basic parameters for stack charge and energy calibration are the instantaneous sampling values ​​of the stack total voltage and total current. The data acquisition system synchronously and continuously collects the voltage signal U(t) and the current signal I(t).

[0180] Secondly, after eliminating noise interference through digital filtering, the pre-processed discrete instantaneous sampling sequences Uk and Ik (k is the sampling point number) are generated and stored in the data buffer queue in real time.

[0181] Third, to calculate power and energy, the sampling period must be determined. Based on the refresh period of the measured parameter, the interception time length T is set. The number of samples, N = T × fs, is calculated from T and the sampling rate fs. N consecutive samples are extracted from the buffer to form a complete sampling period. The total voltage and current of the stack are calculated from these N samples.

[0182] Finally, the charge and energy of the battery stack are the integrals of the instantaneous current and instantaneous power over time, respectively. For accurate calculation, the instantaneous current and instantaneous power are required to be continuous, so the data acquisition system needs to perform continuous and uninterrupted sampling, and the data acquisition and data analysis processes are synchronized and parallel. The calibration device needs to meet the following performance indicators: first, there is zero loss of collected samples, and the number of buffered samples is consistent with the number of read samples; second, the acquisition system should be able to adaptively set the sampling rate and number of samples according to the fluctuation characteristics of the signal; third, it can adaptively select the point-by-point integration algorithm according to the signal characteristics to balance the measurement speed and accuracy. Among them, the point-by-point integration algorithm is designed for the time-varying characteristics of the signal under different working conditions of the battery stack. In the present invention, four numerical integration methods are designed, as shown in Table 1.

[0183] Table 1 Point-by-point integration method

[0184]

[0185] In order to be compatible with the testing of electrolytic hydrogen production stacks, fuel cell stacks and reversible stacks, the calibration device should have the ability to measure both electricity and energy in a bidirectional manner. This corresponds to the working mode of the bidirectional metering unit. By identifying the current direction in real time, the positive / negative electricity, power and energy are accumulated independently: based on the total voltage after signal preprocessing and total current , the instantaneous power of the kth sampling point for: (2)

[0186] In order to achieve bidirectional measurement, it is necessary to construct two new sequences with the same length as the original sequence for the positive and negative instantaneous powers. and The method is: :When P k When ≤0, the value is assigned to 0, otherwise it is retained. P k；

[0187] :When P k When ≥0, the value is assigned to 0, otherwise it is retained. P k .

[0188] Then respectively and Integrate the positive and negative electrical energy separately and The method of treating electric quantity is the same as that of treating electrical energy.

[0189] The working mode of the present invention is described in detail below:

[0190] 1. Single cell voltage inspection and calibration:

[0191] 1. Execution of self-calibration function: Connect the Fluke 5730A high-precision standard voltage source to the calibration interface of the voltage inspection switch array, and use the 8508A high-precision reference standard voltmeter to measure the voltage output of each channel and record it as ; Each channel of the calibration device measures the standard voltage in turn, and the result is recorded as The measurement error of each channel is calculated as follows. (3)

[0192] The consistency of channel measurement is characterized by the experimental standard deviation of the voltage measurement error of each channel. (4)

[0193] 2. Channel Measurement and Error Compensation: The first digital sampling voltmeter (Keysight 34470A DVM1) selects each channel in turn and collects the standard voltage signal from each channel. The absolute error is calculated based on the measured voltage value. Based on the error analysis results, the calibration software automatically generates channel offset compensation values ​​and writes them into the calibration parameter table for that channel.

[0194] 3. Timing Control and Data Acquisition: The host computer sends a binary channel selection command to the synchronous inspection switch array. The synchronous inspection switch array performs a "break-before-make" operation: first, it disconnects the current channel, waits for the relay contact bounce and signal buildup time to disappear, then connects the target channel and outputs a TTL synchronous trigger pulse to the first digital sampling voltmeter DVM1. The rising edge of the pulse triggers the analog-to-digital converter (ADC) of the first digital sampling voltmeter DVM1, continuously acquiring a 1000-point raw voltage sequence at a sampling rate of 50 kS / s.

[0195] 4. Single cell multi-dimensional voltage characterization algorithm:

[0196] Use the host computer software to configure any of the following measurement modes and output the results:

[0197] Instantaneous value mode: output the sample value of any specified index in the sequence ;

[0198] Arithmetic mean mode: Calculation , characterizing the steady-state voltage level;

[0199] RMS Mode: Calculation , quantifying the intensity of voltage fluctuations;

[0200] Range Mode: Calculation , reflecting the transient pressure difference;

[0201] Dispersion Mode: Calculates standard deviation , evaluate signal stability.

[0202] 5. Stack consistency analysis:

[0203] Repeat steps 3 and 4 for all cells to obtain the overall parameters of the stack:

[0204] Voltage value of each cell: ;

[0205] Average voltage of all cells: , reflecting the overall voltage level of the stack;

[0206] All single cell voltage differences: , characterizes the maximum performance deviation;

[0207] Standard deviation of voltage of all cells: , quantifying single-pool consistency.

[0208] 2. Polarization curve parameter calibration

[0209] 1. Hardware synchronization trigger

[0210] Single-cell mode: Switch to the target single cell through the voltage inspection switch array. The single cell voltage is collected by the first digital acquisition voltmeter DVM1, and the loop current is collected by the second digital acquisition voltmeter DVM2 via the current converter (I / V). The first and second digital acquisition voltmeters DVM1 and DVM2 are triggered by pulses emitted by the voltage inspection switch array to achieve strictly synchronized voltage / current collection.

[0211] Stack mode: The stack voltage is connected to the first acquisition channel (CH1) of the synchronous data acquisition card (NI-9239) via a voltage converter (V / V), and the current is connected to the second acquisition channel (CH2) via a current converter (I / V). Configure the sampling rate, conversion coefficient, and dual-channel synchronous acquisition task of the synchronous data acquisition card.

[0212] 2. Dynamic data collection and balance determination

[0213] Set the scan start, end, and rate according to the preset scan mode (constant current CC / constant potential CP / dynamic potential LSV); change the current density in steps, set the step time (dwell time) for each step, and monitor voltage fluctuations in real time; when the ratio of the voltage standard deviation (σ) to the variance (μ) is ≤ 0.01% (adjustable threshold), the stack / cell is determined to be in equilibrium and data acquisition is started.

[0214] 3. Extraction and filtering of effective data points Perform windowed sliding average filtering on the original voltage / current sequence collected synchronously under equilibrium state; calculate the variance μ and standard deviation σ of the filtered sequence. If , then the output is a valid point pair ; Repeat all test points to generate a sequence of discrete polarization point pairs.

[0215] 4. Polarization curve fitting and key parameter analysis

[0216] Fit the effective point pairs into polarization curves and distinguish the rising / falling scanning processes and process them independently;

[0217] Tafel slope calibration: Take a point in the strong polarization region (|η|>100mV) and Linear fitting with overpotential η , the slope b is the Tafel slope, and the formula Verify theoretical conformity;

[0218] Calculation of corrosion current density: Calculated by extrapolating the intersection of the cathode / anode Tafel lines , or based on the Stern-Geary equation calculate;

[0219] Polarization resistance / charge transfer resistance calibration: Fitting slope in linear polarization region , or extract high frequency area by combining EIS data .

[0220] 5. Scan rate error calibration

[0221] The voltage scan rate and current scan rate settings are determined based on specific requirements. For example, a slow scan rate is required to obtain a steady-state polarization curve, while a faster scan rate is required to obtain transient response characteristics (such as passivation film formation). The calibration scan rate is the difference between the set calibration scan rate and the measured value.

[0222] Measured scan rate: or ;

[0223] Calculate setpoints Error from the measured value: or .

[0224] Polarization curve function flow is as follows Figure 7 shown. Figure 7 It is a functional flow chart of the polarization curve of the present invention.

[0225] 3. Bidirectional measurement and calibration of electricity quantity and energy

[0226] 1. Stack total voltage / current calibration

[0227] Synchronous acquisition: Continuously and synchronously sample the total voltage of the stack through a data acquisition card (such as NI-9239) and total current , sampling rate Adaptive signal characteristics ensure time alignment and consistent measurement duration.

[0228] Parameter calculation: Based on Instantaneous sample values , calculate the average: , , RMS value , as well as standard deviation and range are used to assess signal volatility.

[0229] 2. Instantaneous power separation

[0230] Based on the preprocessed discrete sequence and , calculate the instantaneous power at point k .

[0231] Constructing a forward power sequence :when When , the original value is retained, otherwise it is set to zero (corresponding to fuel cell discharge);

[0232] Constructing a negative power sequence :when retain the original value when , otherwise set it to zero (corresponding to electrolysis hydrogen charging).

[0233] 3. Adaptive energy integration

[0234] Dynamically select the integration algorithm based on the time-varying characteristics of the signal (smooth / complex).

[0235] like Figure 8 As shown, Figure 8 This is the data processing flow chart of the power and energy calibration process of the present invention. After the system is initialized (configuration of acquisition parameters, filters and initial integration values), it enters the main cycle: ① The data acquisition cycle continuously reads the total voltage of the battery stack through a synchronous data acquisition card (such as NI-9239) With the total current The instantaneous value of Obtain N samples and store them in the data buffer queue; ② The data analysis loop extracts data from the queue, performs digital filtering noise reduction, calculates real-time parameters (mean / range, etc.), and adaptively selects the integration algorithm (trapezoidal / Simpson / Bode law) based on the time-varying characteristics of the signal to analyze the instantaneous power sequence. Perform point-by-point integration; ③ The data storage cycle will generate bidirectional electrical energy The metering parameters such as power and electricity are output and stored in real time; the above process is executed cyclically from ② to ④ in a "producer-consumer" mode until the calibration is completed, ensuring that there is no sampling loss and the integration is continuous and complete, meeting the metering reliability requirements of steady-state and dynamic working conditions.

[0236] 4. Stack Impedance Calibration

[0237] The equipment used for the stack impedance test includes a host computer: an X86 single-board controller; a synchronous data acquisition device: NI-9239 (24-bit resolution, pre-anti-aliasing filter, 4-channel synchronization, sampling rate: 50k), a V / V converter (RVD1000): 10V~1kV, bandwidth: 1MHz, with a single-gain buffer; an I / V converter (CT-V): 1A~2kA / 5V, bandwidth: 1MHz; a programmable power supply (AC / DC source and load integrated device PRE): DC (1V~600V), AC (1-450)V@10Hz~2kHz.

[0238] 1. Excitation signal application

[0239] A small-amplitude AC excitation voltage with a specific scanning frequency is superimposed on the large-amplitude DC voltage output by the electrolysis power supply, and the composite signal is input into the battery stack to be tested.

[0240] 2. Synchronous data collection

[0241] A dual-channel high-resolution synchronous data acquisition device (including a 24-bit ADC) is used to synchronously collect the stack terminal voltage and electrolysis circuit current signals at a sampling rate at least 10 times the AC signal frequency. A pre-anti-aliasing filter circuit is used to suppress high-frequency noise and aliasing interference to ensure that the original waveform completely contains high-amplitude DC components and low-amplitude AC components.

[0242] 3. Software AC coupling processing

[0243] Calculate the DC average value of the voltage and current sampling waveforms respectively ; From the instantaneous sampling value The DC component is subtracted from the input to separate the pure AC voltage and current signals.

[0244] 4. Frequency domain analysis and parameter extraction

[0245] Perform windowed FFT spectrum analysis on the AC component to obtain the effective value of the voltage , current effective value and the phase difference between the two , and uses sliding average / Kalman filtering to suppress noise, and uses interpolation algorithm to reduce spectrum leakage error.

[0246] 5. Impedance calculation and error compensation

[0247] Calculate the stack impedance according to formula (1).

[0248] 5. Derived Parameter Calibration

[0249] Based on the basic electrical parameters (single cell voltage, total current, total voltage, impedance characteristics, quantity and energy data) obtained from the aforementioned single cell voltage inspection calibration, polarization curve parameter calibration, quantity and energy bidirectional measurement calibration, and stack impedance calibration, as well as system inherent parameters (such as membrane electrode effective area S, number of electrolysis chambers n), the key derived parameters reflecting the comprehensive performance of the electrolysis hydrogen production stack are accurately calculated and calibrated.

[0250] ①Current density calibration:

[0251] Using the calibrated total cell current I and the known membrane electrode active area S, the current density i (A / cm²) is accurately calculated and calibrated using the formula i = I / S. This parameter directly reflects the reaction intensity in the active area of ​​the electrode and is a key indicator for evaluating electrode performance and lifespan.

[0252] ② Hydrogen Production Calibration: Using the calibrated operating DC current I, the known number of electrolysis chambers n, and the preset or measured current efficiency η (%), the hydrogen production Q (Nm³ / h) under standard conditions is accurately calculated and calibrated using the formula Q = (I * n * η) / 2390. This parameter is a core output indicator for measuring the capacity of the hydrogen production system.

[0253] ③Calibration of DC power consumption per unit hydrogen production:

[0254] By comprehensively utilizing the calibrated total electrolysis DC current I, total DC voltage U (V) (or calculated from single-cell voltage calibration data), calibrated hydrogen production Q (Nm³ / h), and test time T (h), or by utilizing the calibrated average single-cell voltage u (V), the DC power consumption per unit hydrogen production, W (kW·h / Nm³), can be accurately calculated and calibrated. The calculation formula is W = (I * U * T) / (Q * 10³), or equivalently, W = (u * 2390) / 10³. This parameter is the most important comprehensive performance indicator for evaluating the energy conversion efficiency and economic viability of hydrogen production systems.

[0255] Although the specific embodiments of the present invention are described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and are not intended to limit the scope of the present invention. Equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An electrical performance calibration device integrating electrolytic hydrogen production and hydrogen fuel cells, characterized in that: include: Host computer, first digital sampling voltmeter, second digital sampling voltmeter, synchronous data acquisition card, synchronous inspection switch, current converter, voltage converter, battery stack, programmable power supply, self-calibration module, external calibration signal source; The synchronous inspection switch is used to detect the single cell voltage bus of the battery stack and then feed back the voltage to the sampling end of the first digital sampling voltmeter, and the feedback end of the first digital sampling voltmeter is connected to the first input end of the host computer; The current converter is used to detect the current loop of the battery stack, convert the detected current signal into an adaptive voltage signal, and then feed it back to the sampling end of the second digital sampling voltmeter and the first acquisition end of the synchronous data acquisition card. The feedback end of the second digital sampling voltmeter is connected to the second input end of the host computer; The voltage converter is used to detect the total voltage of the battery stack, convert the detected voltage signal into an adaptive voltage signal, and then feed it back to the second acquisition terminal of the synchronous data acquisition card. The feedback terminal of the synchronous data acquisition card is connected to the third input terminal of the host computer; The synchronous inspection switch further generates a synchronous acquisition signal, and sends the synchronous acquisition signal to the trigger end of the first digital sampling voltmeter and the trigger end of the second digital sampling voltmeter; The programmable power supply is connected to the power terminal of the battery stack; The external calibration signal source is connected to the power supply terminal of the self-calibration module; The synchronous inspection switch is also used to switch and detect the single resistor voltage bus of the self-calibration module; The host computer has a basic voltage parameter calculation unit, a custom voltage parameter calculation unit, an impedance measurement unit and a bidirectional measurement unit; The battery stack includes N batteries connected in series, the negative electrodes of the N batteries are respectively connected to the left ends of N leads, and the positive electrode of the Nth battery is connected to the left end of the N+1th lead, where N is an integer greater than 2; The self-calibration module includes N resistors connected in series, with a single-gain precision buffer connected in series at both ends of each resistor. The power supply terminals of the N resistors connected in series are connected to the external calibration signal source, and the left ends of the N leads are respectively connected to the N single-gain precision buffers.

2. The electrical performance calibration device for integrating electrolytic hydrogen production and hydrogen fuel cells according to claim 1, characterized in that: The synchronous inspection switch includes a scanning relay group, a polarity relay group, a main controller, a first output bus, and a second output bus; The scanning relay group includes N+1 channel switching relays, the right ends of the N leads are respectively connected to the static contacts of the N channel switching relays, the right end of the N+1th lead is connected to the static contact of the N+1th channel switching relay, and among the N+1 channel switching relays, the moving contacts of the odd-numbered channel switching relays are connected to the first output bus, and the moving contacts of the even-numbered channel switching relays are connected to the second output bus; The polarity relay group includes a first polarity switching relay and a second polarity switching relay, wherein the first static contact of the first polarity switching relay is connected to the first output bus, the second static contact of the first polarity switching relay is connected to the second output bus, the moving contact of the first polarity switching relay is connected to the first sampling terminal of the first digital sampling voltmeter, the first static contact of the second polarity switching relay is connected to the first output bus, the second static contact of the second polarity switching relay is connected to the second output bus, and the moving contact of the second polarity switching relay is connected to the second sampling terminal of the first digital sampling voltmeter; The main controller has N+1 channel selection signal pins, which are respectively connected to the coils of N+1 channel switching relays. The main controller also has a first polarity selection signal pin and a second polarity selection signal pin. The first polarity selection signal pin is connected to the coil of the first polarity switching relay, and the second polarity selection signal pin is connected to the coil of the second polarity switching relay. The main controller also has a synchronous acquisition signal pin, which is connected to the trigger end of the first digital sampling voltmeter and the trigger end of the second digital sampling voltmeter.

3. The electrical performance calibration device for integrating electrolytic hydrogen production and hydrogen fuel cells according to claim 2, characterized in that: The synchronous inspection switch further includes a synchronous pulse output module, and the synchronous acquisition signal pin is connected to the trigger end of the first digital sampling voltmeter and the trigger end of the second digital sampling voltmeter through the synchronous pulse output module.

4. The electrical performance calibration device for integrating hydrogen production by electrolysis and hydrogen fuel cells according to claim 2, characterized in that: The synchronous inspection switch further includes a first cascade port, a second cascade port and a communication module, wherein the first cascade port and the second cascade port are respectively connected to the first cascade signal pin and the second cascade signal pin of the main controller, and the host computer is connected to the main controller through the communication module; There are multiple synchronous patrol switches and they are cascaded to form a synchronous patrol switch array. The first cascade port of the synchronous patrol switch at this level is connected to the second cascade port of the synchronous patrol switch at the previous level, and the second cascade port of the synchronous patrol switch at this level is connected to the first cascade port of the synchronous patrol switch at the next level.

5. A method for calibrating the electrical performance of a fusion electrolytic hydrogen production and hydrogen fuel cell, characterized in that: Use of the electrical performance calibration device according to any one of claims 1 to 4, including self-calibration: First, a standard voltage source is used as an external calibration signal source, combined with a self-calibration module to apply standard DC voltage signals of equal value to the N channels of the synchronous inspection switch. Secondly, a standard square wave signal source is used as an external calibration signal source, combined with a self-calibration module to apply standard square wave signals of equal value to the N channels of the synchronous inspection switch; Finally, a standard signal source is used as an external calibration signal source to generate a signal simulating the actual fluctuating working condition and input it into the self-calibration module.

6. The electrical performance calibration method for integrating hydrogen production by electrolysis and hydrogen fuel cells according to claim 5, characterized in that: It also includes operation timing coordination: First, the host computer sends a channel selection command to the synchronous inspection switch; Secondly, the synchronous inspection switch responds to the command and switches to the target channel; Third, after the channel is stable, the synchronous inspection switch outputs a level trigger signal to the first digital sampling voltmeter; Fourth, the first digital sampling voltmeter receives the trigger signal and starts ADC synchronous sampling; Finally, the sampled data is cached and read by the host computer to complete the data processing.

7. The electrical performance calibration method for integrating hydrogen production by electrolysis and hydrogen fuel cells according to claim 5, characterized in that: Also includes custom voltage parameter measurement algorithms: First, initialization and signal acquisition: start raw signal acquisition according to the preset sampling configuration; Secondly, configurable filtering: dynamically determine whether to enable filtering, and if you choose to apply the filtering algorithm, perform real-time noise suppression; Third, instantaneous data acquisition and storage: obtain the instantaneous sampling value of the current channel and store it in the buffer area; Fourth, closed-loop verification of data validity: Threshold detection is implemented based on the 3σ criterion to verify whether the data conforms to the statistical distribution law; if the data is invalid, it automatically returns to the signal acquisition step to obtain it again; Fifth, parameter algorithm adaptive selection: determines whether to enable the custom algorithm. If the parameter algorithm is selected, the user-defined parameterized calculation model is entered; otherwise, the basic voltage parameters are calculated according to the preset algorithm. Finally, data encapsulation and output: encapsulate the calculation results and report them through the communication interface.

8. The electrical performance calibration method for integrating hydrogen production by electrolysis and hydrogen fuel cells according to claim 5, characterized in that: Also includes stack impedance testing: First, the system is initialized: the data acquisition card is connected to the programmable power supply, and historical status data is cleared; Secondly, parameter configuration: set the sampling frequency / range of the synchronous data acquisition card, configure the power supply output DC bias voltage and modulated AC signal parameters; Third, signal acquisition: synchronously collect the original signals of the stack terminal voltage and electrolysis current; Fourth, low-pass filtering: filter out high-frequency ripple noise through a windowed FIR digital filter; Fifth, AC coupling separation: Calculate the DC average value of the filtered voltage signal and the DC average value of the current signal; subtract the DC component point by point to extract the pure AC modulation voltage and response current; Sixth, spectrum analysis and impedance calculation: Perform FFT on the AC modulated voltage and response current to obtain the voltage fundamental RMS value and initial phase; the current fundamental RMS value and initial phase; and the phase difference between the voltage fundamental initial phase and the current fundamental initial phase at the test frequency. Calculate the stack impedance; Finally, data recording: the impedance spectrum data is stored and the process terminates.

9. The electrical performance calibration method for integrating hydrogen production by electrolysis and hydrogen fuel cells according to claim 5, characterized in that: Also includes bidirectional metering: First, the basic parameters for stack charge and energy calibration are the instantaneous sampling values ​​of the stack total voltage and total current. The synchronous data acquisition card continuously collects voltage and current signals. Secondly, after eliminating noise interference through digital filtering, a pre-processed discrete instantaneous sampling sequence is generated and stored in the data buffer queue in real time; Third, the interception time length is set based on the refresh cycle of the measured parameter. The number of samples is measured by the time length and the sampling rate. Multiple consecutive samples are extracted from the buffer to form a complete sampling cycle. Finally, the stack charge and energy are the integrals of instantaneous current and instantaneous power over time, respectively.

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