Methods, apparatus, equipment and media for optimizing DC-side power in electrolytic hydrogen production systems

Abstract

This invention discloses a method, apparatus, equipment, and medium for optimizing the DC-side power of an electrolytic hydrogen production system, relating to the field of hydrogen production technology. The method includes: filtering the voltage to obtain a denoised discrete-time series of the three-phase voltage; analyzing the DC-side voltage changes based on the discrete-time series of the DC-side three-phase voltage to obtain voltage change parameters; performing power quality detection based on the DC-side voltage change parameters to identify power quality problems on the DC side of the electrolytic hydrogen production system; and suppressing the DC-side power based on these power quality problems to optimize the DC-side power of the electrolytic hydrogen production system. Through real-time acquisition and filtering, high-frequency ripple and second-level low-frequency ripple on the DC side are accurately identified, and power quality problems such as voltage dips are detected. Based on the power quality problem detection results, power quality disturbances are actively suppressed, and precise compensation is implemented at the source of power fluctuations, improving the electro-hydrogen conversion efficiency and the overall reliability of the system.

Description

Technical Field

[0001] This invention relates to the field of hydrogen production technology, and in particular to a method, apparatus, equipment and medium for optimizing the DC side power of an electrolytic hydrogen production system. Background Technology

[0002] As the global energy structure transitions towards a low-carbon model, hydrogen energy, as a clean and efficient secondary energy source, is playing an increasingly important role in industrial decarbonization, transportation, and energy storage. Among the many hydrogen production technologies, using renewable energy sources such as photovoltaics and wind power for water electrolysis is the preferred route for producing "green hydrogen." However, this deep integration also brings many challenges to the stable operation of hydrogen production systems.

[0003] The core equipment for hydrogen production through water electrolysis is the electrolyzer, which works by using direct current to decompose water molecules into hydrogen and oxygen. However, both grid-connected renewable energy power generation systems and off-grid independent hydrogen production systems have inherent and insurmountable defects in their power output.

[0004] Existing technologies attempt to filter and regulate voltage by connecting energy storage devices in parallel on the DC side, but all have obvious shortcomings and there is no effective DC side power optimization solution. Summary of the Invention

[0005] Therefore, it is necessary to propose a method, device, equipment, and medium for optimizing the DC-side power of an electrolytic hydrogen production system to effectively optimize the DC-side power output of the system.

[0006] To achieve the above objectives, the first aspect of this application provides a method for optimizing the DC-side power of an electrolytic hydrogen production system, the method comprising: The three-phase voltage on the DC side of the electrolytic hydrogen production system is acquired in real time, and the acquired voltage is filtered to obtain the discrete time series of the three-phase voltage after noise reduction. The voltage variation parameters of the DC side are obtained by analyzing the discrete time series of the three-phase DC voltage. Power quality is detected based on the voltage change parameters on the DC side to determine the power quality problems on the DC side of the electrolysis hydrogen production system. Based on the power quality issues on the DC side of the electrolytic hydrogen production system, the power on the DC side is suppressed to optimize the power of the DC side of the electrolytic hydrogen production system.

[0007] Furthermore, the voltage variation parameters on the DC side include: the effective value of the voltage, the short-time flicker value, harmonic information, and the unbalance degree; The step of detecting power quality issues on the DC side of the hydrogen electrolysis system based on the voltage change parameters on the DC side specifically includes: Voltage sag analysis is performed based on the effective value of the three-phase voltage on the DC side to determine whether the voltage change on the DC side of the electrolytic hydrogen production system has fallen below the safe depth. Voltage fluctuation analysis is performed based on the short-time flicker value of the DC side voltage to determine whether the voltage fluctuation on the DC side of the electrolysis hydrogen production system exceeds the safety threshold. Voltage distortion analysis is performed based on the harmonic information of the DC side voltage to determine whether the voltage distortion on the DC side of the electrolytic hydrogen production system exceeds the safety limit. Based on the voltage imbalance on the DC side, the voltage amplitude difference of each phase is analyzed to determine whether the DC side imbalance of the electrolytic hydrogen production system exceeds the imbalance threshold.

[0008] Furthermore, the step of performing voltage sag analysis based on the effective value of the three-phase voltage on the DC side to determine whether the voltage change on the DC side of the electrolysis hydrogen production system has fallen below the safe depth specifically includes: The effective values ​​of the three-phase voltages on the DC side are summed and averaged to obtain the average voltage value of the effective values ​​of the three-phase voltages. The rate of voltage drop on the DC side is determined based on the average voltage value. When the voltage drop rate is greater than the voltage drop rate threshold, and the average voltage of the real-time three-phase voltage effective value is less than the effective value threshold, then the voltage change on the DC side of the electrolytic hydrogen production system is determined to have fallen below the safe depth.

[0009] Furthermore, the effective value threshold is calculated using the following formula:

[0010]

[0011] In the formula, For the effective value threshold, To temporarily lower the depth threshold, The rated voltage of the power grid. The minimum DC voltage required to maintain the minimum safe operating power of the electrolyzer. This is to pre-set a safety margin.

[0012] Furthermore, the short-time flicker value of the DC-side voltage is obtained in the following manner: Within a preset observation period, the average value of the real-time effective value of the three-phase voltage is obtained by performing a moving average based on the instantaneous voltage values ​​in the discrete time series of the three-phase voltage. The low-frequency fluctuation envelope signal in the power frequency voltage is calculated based on the average of the instantaneous voltage values ​​in the discrete-time sequence of the three-phase voltage and the effective values ​​of the three-phase voltage; The low-frequency fluctuation envelope signal is input into the transfer function of a preset weighted filter for processing to obtain a weighted and filtered time-domain signal. The time-domain signal is subjected to nonlinear transformation and smoothing to obtain the instantaneous flicker perception within the observation period; By performing cumulative probability statistical analysis on the instantaneous flicker perception within the observation period, the short-time flicker value of the DC side voltage is obtained.

[0013] Furthermore, the harmonic information of the DC-side voltage includes the total harmonic distortion rate and the single harmonic distortion rate; The step of performing voltage distortion analysis based on the harmonic information of the DC-side voltage to determine whether the voltage distortion on the DC side of the electrolysis hydrogen production system exceeds the safety limit specifically includes: When the total harmonic distortion rate is greater than the preset total harmonic distortion rate threshold, or when the single harmonic distortion rate is greater than the preset single harmonic distortion rate threshold at any time, it is determined that the voltage distortion on the DC side of the electrolysis hydrogen production system exceeds the safety limit.

[0014] Furthermore, based on the power quality issues on the DC side of the electrolysis hydrogen production system, the power on the DC side is suppressed to optimize the DC side power of the electrolysis hydrogen production system, specifically including: If the voltage change on the DC side of the electrolysis hydrogen production system falls below the safe depth, the active power support required on the DC side is calculated based on the constant DC power required by the electrolyzer under stable operating conditions, the average value of the real-time three-phase voltage effective value, and the rated voltage of the power grid, and the active power support is added to the control parameter set. If the voltage fluctuation on the DC side of the electrolytic hydrogen production system exceeds the safety threshold, the reactive power required to suppress the voltage envelope fluctuation is calculated based on the reactive power fluctuation in the electrolytic hydrogen production system, and the reactive power is added to the control parameter set. If the voltage distortion on the DC side of the electrolytic hydrogen production system exceeds the safety limit, a preset quasi-resonant controller is used to calculate the compensation harmonic current based on the harmonic information of the DC side voltage, and the compensation harmonic current is added to the control parameter set. If the DC side imbalance of the electrolytic hydrogen production system exceeds the imbalance threshold, the reverse power used to counteract the second harmonic oscillation of the DC side is calculated based on the d-axis / q-axis components of the positive and negative sequence voltage vectors of the DC side in the synchronous rotating coordinate system, and the reverse power is added to the control parameter set. Based on the control parameters in the set of control parameters, a control command is generated by vector superposition. The power of the DC side is suppressed based on the control command, so as to optimize the power of the DC side of the electrolysis hydrogen production system.

[0015] To achieve the above objectives, a second aspect of this application provides a DC-side power optimization device for an electrolytic hydrogen production system, the device comprising: The data acquisition module is used to acquire the three-phase voltage on the DC side of the electrolytic hydrogen production system in real time, and to filter the acquired voltage to obtain the discrete time series of the three-phase voltage after noise reduction. The parameter acquisition module is used to analyze the voltage change on the DC side based on the discrete time series of the three-phase voltage on the DC side, and obtain the voltage change parameters on the DC side. The power optimization module is used to detect power quality based on the voltage change parameters of the DC side, determine the power quality problems of the DC side of the electrolytic hydrogen production system, and suppress the power on the DC side based on the power quality problems of the DC side of the electrolytic hydrogen production system to optimize the power of the DC side of the electrolytic hydrogen production system.

[0016] To achieve the above objectives, a third aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, causes the processor to perform the steps of the method described in the first aspect.

[0017] To achieve the above objectives, a fourth aspect of this application provides a computer device including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the method described in the first aspect.

[0018] The present invention has the following beneficial effects: This invention proposes a method for optimizing the DC-side power of an electrolytic hydrogen production system. The method includes: real-time acquisition of the three-phase voltage on the DC side of the electrolytic hydrogen production system, filtering the acquired voltage to obtain a discrete-time series of the denoised three-phase voltage; analysis of the DC-side voltage variation based on the discrete-time series of the DC-side three-phase voltage to obtain DC-side voltage variation parameters; power quality detection based on the DC-side voltage variation parameters to identify power quality problems on the DC side of the electrolytic hydrogen production system; and suppression of DC-side power based on these power quality problems to optimize the DC-side power of the electrolytic hydrogen production system. This invention first accurately identifies high-frequency ripple and second-level low-frequency ripple on the DC side through real-time acquisition and filtering, and detects power quality problems such as voltage sags, overcoming the shortcomings of traditional lithium-ion batteries, such as slow response and inability to suppress high-frequency interference. Furthermore, based on the power quality problem detection results, it actively suppresses power quality disturbances, implementing precise compensation at the source of power fluctuations, improving the electro-hydrogen conversion efficiency and overall system reliability, and providing a more effective DC-side power optimization solution for renewable energy hydrogen production. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] in: Figure 1 This is a schematic flowchart of the DC-side power optimization method for the electrolytic hydrogen production system in an embodiment of the present invention; Figure 2 This is a structural block diagram of the DC-side power optimization device for the electrolytic hydrogen production system in an embodiment of the present invention; Figure 3 This is an internal structural diagram of a computer device in an embodiment of the present invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Currently, both grid-connected renewable energy power generation systems and off-grid independent hydrogen production systems suffer from inherent and insurmountable defects in their power output. For example, the output power of wind and solar energy exhibits strong randomness and volatility. Cloud cover and sudden changes in wind speed can cause drastic variations in power generation on timescales of seconds or even sub-seconds. This power fluctuation is directly transmitted to the DC side, creating a continuous impact on the electrolyzer, affecting not only the stability of the hydrogen production rate but also causing the electrolyzer to frequently operate in its inefficient range, significantly reducing energy utilization efficiency.

[0023] Meanwhile, both renewable energy power generation and hydrogen production systems rely heavily on power electronic converters. While these converters provide efficient energy conversion, they also introduce complex power quality issues into the system. To address these problems, existing technologies attempt to use parallel energy storage devices on the DC side for filtering and voltage regulation, but all have significant shortcomings, resulting in the current lack of an effective DC-side power optimization solution.

[0024] To address the aforementioned problems, one embodiment of the present invention proposes a method for optimizing the DC-side power of an electrolytic hydrogen production system, which can be found in [reference needed]. Figure 1 , Figure 1 This is a flowchart illustrating the DC-side power optimization method for an electrolytic hydrogen production system according to an embodiment of the present invention. The method includes: Step 100: Real-time acquisition of the three-phase voltage on the DC side of the electrolytic hydrogen production system, and filtering of the acquired voltage to obtain the discrete time series of the denoised three-phase voltage.

[0025] In this embodiment, a voltage transformer (PT) acquires the three-phase DC voltage signal in real time at a preset sampling rate. The voltage signal is then filtered to remove high-frequency noise interference. Specifically, an anti-aliasing filter can be used. After filtering out high-frequency noise using a second- or fourth-order active low-pass filter, its cutoff frequency is set below half the sampling frequency (Nyquist frequency), which can be set to 10kHz to 20kHz. By employing an anti-aliasing design in the filtering stage, the integrity of the signal below the Nyquist frequency is ensured, and high-frequency noise and interference signals above the Nyquist frequency in the input signal are filtered out, preventing aliasing distortion in subsequent digitization processes and improving the signal-to-noise ratio.

[0026] Furthermore, after denoising the voltage signal, an analog-to-digital converter (ADC) is used to convert the acquired voltage signal into discrete voltage data, obtaining a discrete-time series of the three-phase voltages. The ADC employs a multi-channel synchronous sampling architecture to avoid phase deviation. Synchronous sampling, triggered by a unified clock, allows the ADC to simultaneously read the instantaneous values ​​of the three-phase voltages, resulting in a discrete-time series. This synchronous sampling technique (such as phase-locked loop (PLL) synchronization) eliminates phase deviations in the three-phase voltages, providing time-domain aligned raw data for subsequent analysis.

[0027] This embodiment avoids voltage amplitude detection errors caused by harmonic interference by filtering out high-frequency noise, and the synchronous sampling technology reduces the phase deviation of the three-phase voltage, significantly improving the accuracy of subsequent parameter analysis.

[0028] Step 200: Analyze the voltage change on the DC side based on the discrete time series of the three-phase DC voltage to obtain the voltage change parameters on the DC side.

[0029] In this embodiment, voltage transformation parameters such as effective voltage value, flicker component, harmonic distortion rate and voltage imbalance are extracted from the discrete time series of the three-phase voltage on the DC side through operations such as sliding window and Fourier transform, so as to detect and judge the power quality of the system based on the voltage change on the DC side of the electrolytic hydrogen production system.

[0030] This embodiment can simultaneously identify various electrical energy problems such as voltage sag, flicker, harmonics, and imbalance through multi-parameter parallel analysis, thereby shortening the response time and enhancing the accuracy of the detection results.

[0031] Step 300: Perform power quality detection based on the voltage change parameters on the DC side to determine the power quality problems on the DC side of the electrolysis hydrogen production system.

[0032] In this embodiment, a judgment standard for each type of power quality is preset, and the voltage change parameter is used as the judgment basis. The power quality problems existing on the DC side of the electrolysis hydrogen production system are determined by analyzing the voltage change parameter and the judgment standard.

[0033] Step 400: Based on the power quality problem of the DC side of the electrolysis hydrogen production system, suppress the power on the DC side to optimize the power of the DC side of the electrolysis hydrogen production system.

[0034] In this embodiment, based on the detected power quality problems, targeted suppression schemes for different power quality problem responses are generated to achieve better optimization of the DC-side power of the electrolysis hydrogen production system.

[0035] This invention first uses real-time data acquisition and filtering to accurately identify high-frequency ripple and second-level low-frequency ripple on the DC side, and detects power quality issues such as voltage sags, overcoming the shortcomings of traditional lithium-ion batteries, such as slow response and inability to suppress high-frequency interference. In addition, it simultaneously detects multiple electronic quality issues and actively suppresses power quality disturbances based on the power quality issue detection results, implementing precise compensation at the source of power fluctuations, improving the efficiency of the electricity-hydrogen conversion and the overall reliability of the system, and providing a more effective DC-side power optimization solution for renewable energy hydrogen production.

[0036] In one embodiment of the present invention, the voltage variation parameters on the DC side of the electrolytic hydrogen production system include: the effective value of the voltage, the short-time flicker value, harmonic information, and the imbalance degree. After determining the voltage variation parameters on the DC side of the electrolytic hydrogen production system, further processing is performed, and the data is input to four parallel-operating power quality detection modules, which extract features and determine four types of power quality problems respectively. The four power quality detection modules are all logic function modules, which can be implemented using computer instructions, i.e., software code stored in the controller's memory and executed by a digital signal processor, or digital logic circuits constructed using a field-programmable gate array (FPGA). Based on this, step 300, performing power quality detection based on the DC side voltage variation parameters to determine the power quality problems on the DC side of the electrolytic hydrogen production system, specifically includes: S310. Perform voltage sag analysis based on the effective value of the three-phase voltage on the DC side to determine whether the voltage change on the DC side of the electrolysis hydrogen production system has fallen below the safe depth.

[0037] In this embodiment, a sliding window is set up to calculate the effective value of each phase voltage.

[0038] Specifically, a sliding window is used to sample the discrete-time series of voltages in any phase, the mean of the instantaneous voltage values ​​within the sliding window is calculated, and this mean is used as the effective voltage value corresponding to the median time of the current sliding window, thereby obtaining the effective voltage value of each phase.

[0039] Furthermore, after determining the effective values ​​of the three-phase voltages on the DC side of the system, the voltage sag module calculates the voltage change rate in real time based on the effective voltage values. The effective values ​​and voltage change rates of the three-phase voltages are used to determine whether the voltage change on the DC side of the electrolysis hydrogen production system has fallen below the safe depth. Specifically, this includes the following steps: S311. Sum and average the effective values ​​of the three-phase voltages on the DC side to obtain the average voltage value of the effective values ​​of the three-phase voltages.

[0040] In this embodiment, the average voltage value of the three-phase voltage is obtained by summing and averaging the effective values ​​of the three-phase voltages on the DC side.

[0041] S312. Determine the voltage drop rate on the DC side based on the average voltage value; when the voltage drop rate is greater than the voltage drop rate threshold, and the average voltage value of the real-time three-phase voltage is less than the effective value threshold, then determine the voltage drop depth of the DC side of the electrolytic hydrogen production system.

[0042] In this embodiment, the criterion for determining whether a voltage sag has fallen below the safe depth is:

[0043] In the formula, It is the average voltage value of the effective value of the three-phase voltage over the time of change. For the duration of the change, The voltage drop rate threshold, The average voltage value is the real-time effective value of the three-phase voltage. To temporarily lower the depth threshold, This is the rated voltage of the power grid.

[0044] In the formula, This represents the rate of voltage drop on the DC side, indicating the speed at which the voltage drops. If the rate of drop is too fast, exceeding the voltage drop rate threshold, it is suppressed. This represents what happens if the voltage drops to a certain value (i.e.) Suppression is performed when the voltage drops too quickly or too much (when the voltage drops to twice the rated voltage). This criterion can be understood as suppression occurring when the voltage drops too rapidly or too much.

[0045] In one embodiment, the effective value threshold is calculated using the following formula:

[0046]

[0047] In the formula, For the effective value threshold, To temporarily lower the depth threshold, The rated voltage of the power grid. The minimum DC voltage required to maintain the minimum safe operating power of the electrolyzer. This is a preset safety margin. 1.35 It is based on the rectified DC voltage determined by the three-phase six-pulse rectifier, through... The minimum voltage on the AC side is determined to obtain the sag depth threshold.

[0048] In one embodiment, using the statistical method of 3 The principle is that normal power grid fluctuations follow a normal distribution. Therefore, a sudden change exceeding three standard deviations has a 99.7% probability of being a voltage sag. Thus, the controller optimizing the DC-side power of the electrolysis hydrogen production system continuously calculates the dynamic standard deviation over a period of time. And set it. Specifically, the voltage drop rate threshold is determined by the following formula:

[0049] In the formula, The voltage drop rate threshold, The standard deviation of the rate of change of voltage is calculated in real time over a period of time. The sensitivity coefficient is set to 3-5. It is the basic dead zone value to prevent misjudgment of voltage dips when the power grid fluctuations are extremely small.

[0050] S320. Based on the short-time flicker value of the DC side voltage, perform voltage fluctuation analysis to determine whether the voltage fluctuation on the DC side of the electrolysis hydrogen production system exceeds the safety threshold.

[0051] In this embodiment, the short-time flicker value of the DC-side voltage is obtained in the following manner: A1. Within the preset observation period, the average value of the real-time effective value of the three-phase voltage is obtained by performing a moving average based on the instantaneous voltage values ​​in the discrete time series of the three-phase voltage.

[0052] In this embodiment, within a preset observation period, a slow moving average is performed on the instantaneous voltage values ​​in the discrete time series of each phase voltage to obtain the average value of the real-time three-phase voltage effective values.

[0053] A2. The low-frequency fluctuation envelope signal in the power frequency voltage is calculated based on the average value of the instantaneous voltage value and the effective value of the three-phase voltage in the discrete time series of the three-phase voltage.

[0054] In this embodiment, the real-time acquired instantaneous values ​​of the three-phase voltage are normalized and demodulated to extract the voltage fluctuation components that can cause flicker:

[0055] In the formula, This is the raw instantaneous voltage value acquired in real time. This is the average of the real-time effective values ​​of the three-phase voltage, i.e., the average effective value over a period of time. This step simulates the physical characteristic that the luminous flux of an incandescent lamp is proportional to the square of the input voltage through square operations, thereby demodulating the low-frequency fluctuation envelope signal hidden in the power frequency voltage. .

[0056] A3. Input the low-frequency fluctuation envelope signal into the transfer function of the preset weighted filter for processing to obtain the weighted filtered time-domain signal.

[0057] In this embodiment, the regulated signal, i.e., the low-frequency fluctuation envelope signal, is input to a visual sensitivity weighted filter. The frequency response characteristics of this filter are determined by the transfer function H(s) defined in the IEC 61000-4-15 standard. The transfer function H(s) aims to accurately simulate the frequency response characteristics of the "standard light bulb-human eye-brain" system to voltage fluctuations. The transfer function is defined as follows:

[0058] In the formula, the values ​​are based on the definition of the visual sensitivity weighting curve for flicker measurement at 230V in the IEC 61000-4-15 standard. H(s) is the transfer function of the weighting filter, k is the gain function, set to 1.74802; λ is the damping coefficient, set to 2π×4.059812π×4.05981rad / s; The center frequency is set to 2π×9.154942π×9.15494rad / s; It is the zero-point frequency, set to 2π×2.279792π×2.27979rad / s; The first pole frequency is set to 2π×1.22535. The second pole frequency is set to 2π×21.92π×21.9 rad / s. s is the complex frequency component, set to 1.74802.

[0059] The demodulated voltage fluctuation signal The input is fed into the filter defined above for processing. This linear filtering process is described in the frequency domain as follows:

[0060] The obtained output data is subjected to inverse Laplace transform to obtain the time-domain signal y(t).

[0061] In practice, the continuous transfer function H(s) is discretized into a time-domain difference equation using the bilinear transform method. This allows for the real-time sampling... Substitute the values ​​into the difference equation and perform iterative calculations to directly output the time-domain signal y(t) after weighted filtering.

[0062] A4. Perform nonlinear transformation and smoothing on the time-domain signal to obtain the instantaneous flicker perception within the observation period.

[0063] In this embodiment, the weighted filtered time-domain signal y(t) undergoes nonlinear transformation and smoothing to obtain real-time instantaneous flicker perception. This process is described by the following integral formula:

[0064] In the formula, The square operation is represented by a pre-defined nonlinear variation function that simulates the nonlinear characteristics of visual perception. It is the impulse response function of a first-order low-pass filter with a time constant of 300ms.

[0065] A5. Perform cumulative probability statistical analysis on the instantaneous flicker perception within the observation period to obtain the short-time flicker value of the DC side voltage.

[0066] In this embodiment, cumulative probability statistical analysis is performed on the time series data of transient flicker perception S(t) generated within the observation period (standard is 10 minutes), key percentile values ​​are extracted and the final index is calculated. The short-time flicker value of the DC side voltage is calculated by the following formula:

[0067] In the formula, K is a weighting coefficient; the larger the value, the greater the proportion and the higher the influence. 0.1 =0.0314, K1=0.0525,, K3=0.0657, K 10 =0.28, K 50 =0.08. P 0.1 P1, P3, P 10 P 50 These refer to the periods during which the transient flicker sensitivity S(t) exceeds the value at 0.1%, 1%, 3%, 10%, and 50% of the observation period, respectively. Specifically, first, the transient flicker sensitivity for all times within the observation period is calculated, then these are arranged from highest to lowest, with the 0.1% value being P. 0.1 Data ranked in the top 1% is P1, data ranked in the top 3% is P3, and data ranked in the top 10% is P4. 10 Data ranking in the top 50% is P. 50 .

[0068] Furthermore, the voltage flicker detection module operates a digital flicker meter algorithm conforming to the IEC61000-4-15 standard. Essentially, it simulates the objective quantity of voltage fluctuations as a biological algorithm, identifying and suppressing the parts of voltage fluctuations to which humans are most sensitive. The judgment logic checks whether the short-time flicker value exceeds a threshold. After determining the short-time flicker value of the DC-side voltage, it judges whether the voltage fluctuation on the DC side of the electrolysis hydrogen production system exceeds a safety threshold based on a preset flicker threshold. The judgment condition is:

[0069] In the formula, It is the short-time flicker value of the DC-side voltage. It is the preset flicker threshold.

[0070] When the short-time flicker value of the DC side voltage exceeds the flicker threshold, it is considered that the voltage fluctuation on the DC side of the electrolytic hydrogen production system exceeds the safety threshold, and it needs to be suppressed.

[0071] S330. Based on the harmonic information of the DC side voltage, perform voltage distortion analysis to determine whether the voltage distortion on the DC side of the electrolytic hydrogen production system exceeds the safety limit.

[0072] In this embodiment, the harmonic information of the DC-side voltage includes the total harmonic distortion rate (THD) and the single harmonic distortion rate (SH). Fast Fourier Transform (FFT) analysis is continuously performed on the instantaneous values ​​of the synchronously received three-phase voltages to extract their spectral information.

[0073]

[0074] In the formula, It is the total harmonic distortion rate. V 1 is the effective value of the fundamental voltage. V h It is the effective value of the h-th harmonic voltage. H max This represents the harmonic order corresponding to the upper frequency limit used by the system for FFT calculations. The effective value of a specific harmonic component extracted from the FFT analysis is... It is the single harmonic distortion rate.

[0075] Furthermore, the voltage harmonic detection module checks whether the total harmonic distortion (THD) and amplitude of each harmonic exceed the limits specified in the "Power Quality Public Grid Harmonics" standard. This limit is determined based on the nominal voltage of the power grid; for 380V, the THD limit is 5.0%, for 6-10kV it is 4.0%, for 35-66kV it is 3.0%, and for 110kV it is 2.0%. Specifically, S330 performs voltage distortion analysis based on the harmonic information of the DC-side voltage to determine whether the voltage distortion on the DC side of the electrolysis hydrogen production system exceeds the safety limit. Specifically, if the THD is greater than a preset THD threshold, or if any single harmonic distortion is greater than a preset single harmonic distortion threshold, then the voltage distortion on the DC side of the electrolysis hydrogen production system exceeds the safety limit.

[0076] In this embodiment, the determination condition is:

[0077] in, It is the total harmonic distortion rate; It is the total harmonic distortion rate threshold; It is the single harmonic distortion rate. K h This is the single-pass distortion rate threshold. If the voltage distortion on the DC side of the electrolytic hydrogen production system is determined to exceed the safety limit, it will be suppressed.

[0078] S340. Analyze the voltage amplitude differences of each phase based on the voltage imbalance on the DC side to determine whether the DC side imbalance of the electrolytic hydrogen production system exceeds the imbalance threshold.

[0079] In this embodiment, the digital signal processor uses the symmetrical component method to decompose the acquired three-phase voltage into positive-sequence and negative-sequence components. Through real-time Clarke transform and notch filter, the positive-sequence voltage vector is extracted. V pos |and negative sequence voltage vector| V neg The phase-locked loop (PLL) synchronization software uses a PLL to track the fundamental frequency and phase of the power grid in real time, constructing a synchronous rotating coordinate system to ensure that subsequent calculations are adaptive to the power grid frequency. Using the Clarke transform, a real-time processor (DSP or FPGA) performs a linear algebraic transformation (matrix operation) on the sampled discrete data. The data in the three-phase stationary coordinate system is obtained by collecting and filtering the voltage of each phase from the three-phase voltage transformers; the discrete time series and the data in the three-phase stationary coordinate system are identical. The data in the three-phase stationary coordinate system is then transformed into data in a two-phase stationary coordinate system:

[0080]

[0081]

[0082] In the formula, v a , v b , v c It is a three-phase voltage. , The processed data in the two-phase stationary coordinate system is the synthesized three-phase voltage. , This provides the amplitude and phase information for the synthesized three-phase voltage. Data from the two-phase stationary coordinate system includes... and The original three-phase voltages are projected onto a two-dimensional Cartesian coordinate system, where... and v a Voltage axes coincide. These are the real axis coordinates in a rectangular coordinate system; Depend on v b , v c It is synthesized and serves as the imaginary axis of the rectangular coordinate system. It can be used to synthesize the magnitude and angle of the voltage vector.

[0083] In this embodiment, the three-phase voltage imbalance is determined by the following formula: VUR(%)=|V neg ||V pos |×100% Furthermore, the three-phase imbalance detection module's judgment logic checks the degree of three-phase voltage imbalance. VUR Does it exceed the threshold?

[0084] If the three-phase voltage imbalance exceeds the preset imbalance threshold, it will be suppressed.

[0085] In this embodiment of the invention, the judgment criteria are automatically adjusted according to the power grid operating conditions to improve system robustness. It also simultaneously detects multiple power quality problems, making it suitable for complex power grid environments.

[0086] In one embodiment of the present invention, step 400, based on the power quality problem of the DC side of the electrolysis hydrogen production system, suppresses the power on the DC side to optimize the power of the DC side of the electrolysis hydrogen production system, specifically includes: S410. If the voltage change on the DC side of the electrolysis hydrogen production system falls below the safe depth, the active power support required on the DC side is calculated based on the constant DC power required by the electrolyzer under stable operating conditions, the average value of the real-time three-phase voltage effective value, and the rated voltage of the power grid, and the active power support is added to the control parameter set.

[0087] In this embodiment, if the voltage change on the DC side of the electrolysis hydrogen production system falls below the safe depth, the voltage change needs to be suppressed. The specific suppression formula is as follows:

[0088] In the formula, This refers to the active power that the hybrid capacitor needs to inject into the DC bus. It is the constant DC power required by the electrolytic cell under stable operating conditions. It is the average voltage value of the real-time effective value of the three-phase voltage. That is the rated line voltage.

[0089] After calculating the required active power support on the DC side, the active power support is added to the control parameter set for further suppression operations.

[0090] S420. If the voltage fluctuation on the DC side of the electrolytic hydrogen production system exceeds the safety threshold, calculate the reactive power required to suppress the voltage envelope fluctuation based on the reactive power fluctuation in the electrolytic hydrogen production system, and add the reactive power to the control parameter set.

[0091] In this embodiment, if the voltage fluctuation on the DC side of the electrolytic hydrogen production system exceeds the safety threshold, the voltage fluctuation needs to be suppressed. The hybrid capacitor will actively suppress the voltage fluctuation caused by voltage flicker through rapid reactive power compensation.

[0092] Voltage fluctuations that cause flicker Mainly composed of reactive power in the system The relationship between the two, caused by fluctuations, is approximately as follows:

[0093] In the formula, It is the system short-circuit reactance.

[0094] voltage fluctuation This is achieved by calculating the difference between it and the moving average:

[0095] In the formula, It is the slow moving average of the effective voltage value. It is the real-time measured effective value of the phase voltage. It can be the effective value of the phase voltage of any one of the three phases.

[0096] The hybrid capacitor will inject one and Compensating reactive power of equal magnitude but opposite direction :

[0097] The calculated reactive power compensation Then, the reactive power Add it to the set of control parameters for further suppression operations.

[0098] S430. If the voltage distortion on the DC side of the electrolytic hydrogen production system exceeds the safety limit, the preset quasi-resonant controller is used to calculate the compensation harmonic current based on the harmonic information of the DC side voltage, and the compensation harmonic current is added to the control parameter set.

[0099] In this embodiment, if the voltage distortion on the DC side of the electrolytic hydrogen production system exceeds the safety limit, it is necessary to suppress the harmonic voltage.

[0100] First, from the original signal In the process, all target harmonic voltage waveforms that need to be eliminated are reconstructed, which are the harmonics that meet the threshold, i.e., the total harmonic distortion rate or the single harmonic distortion rate exceeds the limit:

[0101] in, It is the set of all harmonic orders exceeding the standard. A single Instantaneous voltage of subharmonics Amplitude that can be obtained from FFT analysis and phase Refactoring:

[0102] In the formula, This is a standard voltage waveform function, and the formula is mainly determined by the amplitude and phase.

[0103] Hybrid capacitors inject compensation current into the DC side With target harmonic voltage Proportional to each other, used to cancel harmonics:

[0104] in, The control transfer function minimizes the harmonic content of the compensated bus voltage, through a controller. To achieve this, adjustments will be made according to different scenarios.

[0105] In one embodiment, a quasi-resonant controller is used for compensation of a specific harmonic (e.g., the h-th harmonic). Its transfer function... The specific form is as follows:

[0106] In the formula, It is the proportional gain, which is responsible for improving the overall response speed and high-frequency stability of the system; The resonant gain determines the controller's effectiveness in eliminating harmonics at the target harmonic frequency. The larger the value, the more thorough the elimination of the harmonic. The resonant frequency is the fundamental angular frequency of the power grid. Here, h represents the harmonic order. At this frequency point, the controller and harmonic frequencies are the same, and the controller gain becomes infinitely large, thus achieving zero steady-state error compensation. This is the cutoff frequency (i.e., the damping term), preventing the resonant compensator from being overly sensitive to frequency, causing the compensation effect to fail when the grid frequency increases or decreases. Afterward, the resonant peak becomes wider, giving the controller a certain degree of robustness to grid frequency adjustments.

[0107] After calculating the compensation harmonic current, the compensation harmonic current is added to the control parameter set for further suppression operations.

[0108] S440. If the DC side imbalance of the electrolytic hydrogen production system exceeds the imbalance threshold, the reverse power used to counteract the second harmonic oscillation of the DC side is calculated based on the d-axis / q-axis components of the positive and negative sequence voltage vectors of the DC side in the synchronous rotating coordinate system, and the reverse power is added to the control parameter set.

[0109] In this embodiment, if the DC-side imbalance of the hydrogen electrolysis system exceeds the imbalance threshold, the voltage imbalance needs to be suppressed. The hybrid capacitor will eliminate second harmonic power pulsations on the DC side.

[0110] Under three-phase unbalanced conditions, the instantaneous power p(t) is not constant and contains a constant component. P 0 and an oscillating component P 2ω(t) In a synchronously rotating coordinate system, the oscillation power can be accurately calculated as follows:

[0111] in, These represent the d-axis and q-axis components of the positive-sequence voltage vector in the synchronously rotating coordinate system. These represent the d-axis and q-axis components of the negative sequence voltage in a synchronously rotating coordinate system. These represent the d-axis and q-axis components of the negative sequence current in a synchronously rotating coordinate system. The positive sequence current is represented by its d-axis and q-axis components in a synchronous rotating coordinate system.

[0112] This embodiment requires the generation of reverse power to counteract the second harmonic oscillation on the DC side. The oscillation component mentioned above is equal in magnitude but opposite in direction:

[0113] After calculating the reverse power, the reverse power is added to the control parameter set for further suppression operations.

[0114] S450. Based on the control parameters in the control parameter set, vector superposition is performed to generate control commands, so as to suppress the DC side power based on the control commands, thereby optimizing the DC side power of the electrolysis hydrogen production system.

[0115] In this embodiment, the judgment results of the above four modules generate corresponding control strategies: if the voltage sag detection module is triggered, the required active power is calculated using the formula to clamp the DC bus voltage; if the voltage flicker detection module is triggered, the reactive power required to suppress voltage envelope fluctuations is calculated; if the voltage harmonic detection module is triggered, the compensation current opposite to the target harmonic is calculated according to the formula, and active filtering is performed; if the three-phase voltage imbalance detection module is triggered, the reverse power that can offset the second harmonic oscillation on the DC side is calculated according to the formula.

[0116] The active, reactive, and harmonic current commands generated by the above four modules are vector-superimposed to form the overall control command, specifically: Voltage sag current:

[0117] Three-phase unbalance current:

[0118] Harmonic current:

[0119] Voltage flicker current:

[0120] Total current:

[0121] The system checks whether the total current required for the control command exceeds the maximum rated current of the energy conversion system. If an over-limit occurs, the system executes a priority reduction strategy, prioritizing the execution of high-priority tasks in the order of "voltage sag > three-phase imbalance > harmonic suppression > voltage flicker." The total control command or optimized final command is converted into a high-frequency PWM drive signal. The PCS drives the hybrid capacitor for rapid charging and discharging, optimizing the power balance and voltage quality of the DC bus, and feeding back to influence the sampling of the next cycle, forming a closed-loop control. If the over-limit is not exceeded, the active, reactive, and harmonic current quality are vector-superimposed to form the total control command, which is executed normally.

[0122] One embodiment of the present invention proposes a DC-side power optimization device for an electrolytic hydrogen production system, which can be referred to as [reference needed]. Figure 2 , Figure 2 This is a structural block diagram of the DC-side power optimization device for an electrolytic hydrogen production system according to an embodiment of the present invention. The device includes: The data acquisition module 201 is used to acquire the three-phase voltage on the DC side of the electrolytic hydrogen production system in real time, and to filter the acquired voltage to obtain the discrete time series of the three-phase voltage after noise reduction. The parameter acquisition module 202 is used to analyze the voltage change on the DC side based on the discrete time series of the three-phase voltage on the DC side, and obtain the voltage change parameters on the DC side. The power optimization module 203 is used to detect power quality based on the voltage change parameters on the DC side, identify power quality problems on the DC side of the electrolysis hydrogen production system, and suppress the power on the DC side based on the power quality problems on the DC side of the electrolysis hydrogen production system to optimize the power on the DC side of the electrolysis hydrogen production system.

[0123] The DC-side power optimization device for the electrolytic hydrogen production system proposed in this embodiment first accurately identifies high-frequency ripple and second-level low-frequency ripple on the DC side through real-time acquisition and filtering, and detects power quality problems such as voltage sag, in order to overcome the shortcomings of traditional lithium-ion batteries, such as slow response and inability to suppress high-frequency interference. In addition, it simultaneously detects multiple electronic quality problems, and actively suppresses power quality disturbances based on the power quality problem detection results, and implements precise compensation at the source of power fluctuations, thereby improving the efficiency of the electro-hydrogen conversion and the overall reliability of the system, and providing a more effective DC-side power optimization solution for renewable energy hydrogen production.

[0124] Figure 3 An internal structural diagram of a computer device according to one embodiment of the present invention is shown. This computer device can specifically be a terminal or a system. Figure 3As shown, the computer device includes a processor, memory, and network interface connected via a system bus. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system and may also store a computer program. When executed by the processor, this computer program causes the processor to perform the steps in the above-described method embodiments. The internal memory may also store a computer program, which, when executed by the processor, causes the processor to perform the steps in the above-described method embodiments. Those skilled in the art will understand that... Figure 3 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0125] In one embodiment, a computer device is provided, including a memory and a processor, the memory storing a computer program that, when executed by the processor, causes the processor to perform the steps in the above method embodiments.

[0126] In one embodiment, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, causes the processor to perform the steps in the above method embodiments.

[0127] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments described above. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM), etc.

[0128] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0129] The embodiments described above are merely examples of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application.

Claims

1. A method for optimizing the DC-side power of an electrolytic hydrogen production system, characterized in that, The method includes: The three-phase voltages on the DC side of the electrolytic hydrogen production system are acquired in real time, and the acquired voltages are filtered to obtain the discrete time series of the denoised three-phase voltages. The voltage variation parameters of the DC side are obtained by analyzing the discrete time series of the three-phase DC voltage. Power quality is detected based on the voltage change parameters on the DC side to determine the power quality problems on the DC side of the electrolysis hydrogen production system. Based on the power quality issues on the DC side of the electrolytic hydrogen production system, the power on the DC side is suppressed to optimize the power of the DC side of the electrolytic hydrogen production system.

2. The method as described in claim 1, characterized in that, The voltage variation parameters on the DC side include: the effective value of the voltage, the short-time flicker value, harmonic information, and the unbalance. The step of detecting power quality issues on the DC side of the hydrogen electrolysis system based on the voltage change parameters on the DC side specifically includes: Voltage sag analysis is performed based on the effective value of the three-phase voltage on the DC side to determine whether the voltage change on the DC side of the electrolytic hydrogen production system has fallen below the safe depth. Voltage fluctuation analysis is performed based on the short-time flicker value of the DC side voltage to determine whether the voltage fluctuation on the DC side of the electrolysis hydrogen production system exceeds the safety threshold. Voltage distortion analysis is performed based on the harmonic information of the DC side voltage to determine whether the voltage distortion on the DC side of the electrolytic hydrogen production system exceeds the safety limit. Based on the voltage imbalance on the DC side, the voltage amplitude difference of each phase is analyzed to determine whether the DC side imbalance of the electrolytic hydrogen production system exceeds the imbalance threshold.

3. The method as described in claim 2, characterized in that, The step of performing voltage sag analysis based on the effective value of the three-phase voltage on the DC side to determine whether the voltage change on the DC side of the electrolysis hydrogen production system has fallen below the safe depth specifically includes: The effective values ​​of the three-phase voltages on the DC side are summed and averaged to obtain the average voltage value of the effective values ​​of the three-phase voltages. The rate of voltage drop on the DC side is determined based on the average voltage value. When the voltage drop rate is greater than the voltage drop rate threshold, and the average voltage of the real-time three-phase voltage effective value is less than the effective value threshold, then the voltage change on the DC side of the electrolytic hydrogen production system is determined to have fallen below the safe depth.

4. The method as described in claim 3, characterized in that, The effective value threshold is calculated using the following formula: In the formula, For the effective value threshold, To temporarily lower the depth threshold, The rated voltage of the power grid. The minimum DC voltage required to maintain the minimum safe operating power of the electrolyzer. This is to pre-set a safety margin.

5. The method as described in claim 2, characterized in that, The short-time flicker value of the DC-side voltage is obtained in the following manner: Within a preset observation period, the average value of the real-time effective value of the three-phase voltage is obtained by performing a moving average based on the instantaneous voltage values ​​in the discrete time series of the three-phase voltage. The low-frequency fluctuation envelope signal in the power frequency voltage is calculated based on the average of the instantaneous voltage values ​​in the discrete-time sequence of the three-phase voltage and the effective values ​​of the three-phase voltage; The low-frequency fluctuation envelope signal is input into the transfer function of a preset weighted filter for processing to obtain a weighted and filtered time-domain signal. The time-domain signal is subjected to nonlinear transformation and smoothing to obtain the instantaneous flicker perception within the observation period; The short-time flicker value of the DC side voltage is obtained by performing cumulative probability statistical analysis on the instantaneous flicker perception within the observation period.

6. The method as described in claim 2, characterized in that, The harmonic information of the DC side voltage includes the total harmonic distortion rate and the single harmonic distortion rate. The step of performing voltage distortion analysis based on the harmonic information of the DC-side voltage to determine whether the voltage distortion on the DC side of the electrolysis hydrogen production system exceeds the safety limit specifically includes: When the total harmonic distortion rate is greater than the preset total harmonic distortion rate threshold, or when the single harmonic distortion rate is greater than the preset single harmonic distortion rate threshold at any time, it is determined that the voltage distortion on the DC side of the electrolysis hydrogen production system exceeds the safety limit.

7. The method as described in claim 2, characterized in that, The method addresses the power quality issues on the DC side of the electrolytic hydrogen production system by suppressing the power on the DC side to optimize the DC power of the system. Specifically, this includes: If the voltage change on the DC side of the electrolysis hydrogen production system falls below the safe depth, the active power support required on the DC side is calculated based on the constant DC power required by the electrolyzer under stable operating conditions, the average value of the real-time three-phase voltage effective value, and the rated voltage of the power grid, and the active power support is added to the control parameter set. If the voltage fluctuation on the DC side of the electrolytic hydrogen production system exceeds the safety threshold, the reactive power required to suppress the voltage envelope fluctuation is calculated based on the reactive power fluctuation in the electrolytic hydrogen production system, and the reactive power is added to the control parameter set. If the voltage distortion on the DC side of the electrolytic hydrogen production system exceeds the safety limit, a preset quasi-resonant controller is used to calculate the compensation harmonic current based on the harmonic information of the DC side voltage, and the compensation harmonic current is added to the control parameter set. If the DC side imbalance of the electrolytic hydrogen production system exceeds the imbalance threshold, the reverse power used to counteract the second harmonic oscillation of the DC side is calculated based on the d-axis / q-axis components of the positive and negative sequence voltage vectors of the DC side in the synchronous rotating coordinate system, and the reverse power is added to the control parameter set. Based on the control parameters in the set of control parameters, a control command is generated by vector superposition. The power of the DC side is suppressed based on the control command, so as to optimize the power of the DC side of the electrolysis hydrogen production system.

8. A DC-side power optimization device for an electrolytic hydrogen production system, characterized in that, The device includes: The data acquisition module is used to acquire the three-phase voltage on the DC side of the electrolytic hydrogen production system in real time, and to filter the acquired voltage to obtain the discrete time series of the three-phase voltage after noise reduction. The parameter acquisition module is used to analyze the voltage change on the DC side based on the discrete time series of the three-phase voltage on the DC side, and obtain the voltage change parameters on the DC side. The power optimization module is used to detect power quality based on the voltage change parameters of the DC side, determine the power quality problems of the DC side of the electrolytic hydrogen production system, and suppress the power on the DC side based on the power quality problems of the DC side of the electrolytic hydrogen production system to optimize the power of the DC side of the electrolytic hydrogen production system.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it causes the processor to perform the steps of the method as described in any one of claims 1 to 7.

10. A computer device, comprising a memory and a processor, characterized in that, The memory stores a computer program that, when executed by the processor, causes the processor to perform the steps of the method as described in any one of claims 1 to 7.

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