Switching frequency test method and system for network-forming type energy storage converter module

Abstract

The invention relates to the technical field of energy storage converters, in particular to a switching frequency testing method and system for a network-forming type energy storage converter module. According to the method, the switching characteristic oscillogram of the network-forming type energy storage converter in the full-load and half-load states is obtained, and the switching signal, the current waveform and the voltage waveform are obtained and analyzed, so that the behaviors of the converter in different load states can be comprehensively analyzed, the duty ratio and the response duration can be accurately calculated, and the reliability of the converter is improved. The method can help to judge the performance of a switch element in different working states, can effectively identify periodic components and harmonic waves in a signal through frequency domain analysis, reduces the influence of electromagnetic interference and noise on a time domain signal, and obtains the total loss of a switch through full-load and half-load switching frequencies. The problem of inaccurate switching frequency measurement caused by electromagnetic interference and noise influence can be effectively solved, and the accuracy of loss calculation and the effectiveness of stability performance evaluation are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage converters, and in particular to a switching frequency testing method and system for a grid-type energy storage converter module. Background Art

[0002] A grid-type energy storage converter is a power electronic device used to connect an energy storage system (such as a battery) to a power grid. Its main function is to convert direct current into alternating current to supply the power grid or power load. The grid-type converter is particularly suitable for the integration of renewable energy (such as solar energy and wind energy), microgrid systems, and large-scale energy storage systems. Switch testing is the process of evaluating and measuring the performance of switching elements in a grid-type energy storage converter.

[0003] In actual testing, the switching signal waveform may be affected by electromagnetic interference, noise, etc., which makes the signal captured by an oscilloscope or spectrum analyzer not clear enough, resulting in inaccurate measurement of the switching frequency. Summary of the invention

[0004] The main purpose of the present invention is to provide a switching frequency testing method for a grid-type energy storage converter module, aiming to solve the technical problems in the prior art.

[0005] The present invention provides a switching frequency testing method for a grid-type energy storage converter module, comprising:

[0006] Obtaining a full-load switch characteristic waveform diagram and a half-load switch characteristic waveform diagram of the grid-type energy storage converter under full-load and half-load states, respectively, wherein the full-load switch characteristic waveform diagram includes a switch signal waveform diagram, a current waveform diagram, and a voltage waveform diagram;

[0007] Obtaining a duty cycle and a response duration according to the switch signal waveform diagram, and obtaining a total cycle according to the duty cycle and the response duration;

[0008] Obtaining an average output current and an average output voltage according to the current waveform diagram and the voltage waveform diagram, respectively, and obtaining an average output power according to the average output voltage and the average output current;

[0009] Acquire a time domain waveform of the switch signal waveform diagram, and convert the time domain waveform into a frequency domain waveform according to Fourier transform to obtain a frequency spectrum;

[0010] Obtaining total harmonic distortion according to the frequency spectrum, and obtaining full-load switching frequency according to the total harmonic distortion, average output power and total period;

[0011] Acquire a half-load switching frequency according to the half-load switching characteristic waveform diagram;

[0012] The total switching loss is obtained according to the full-load switching frequency and the half-load switching frequency, and the stability performance of the grid-type energy storage converter is evaluated according to the total switching loss.

[0013] Preferably, the step of acquiring the duty cycle and the response time according to the switching signal waveform diagram comprises:

[0014] Acquire the cycle duration according to the switching signal waveform diagram;

[0015] Acquire multiple high-level moments and multiple low-level moments within the cycle duration according to the switch signal waveform diagram, and respectively acquire the high-level duration and the low-level duration according to the multiple high-level moments and the multiple low-level moments;

[0016] Obtain the total falling time from two adjacent high-level moments to low-level moments;

[0017] Obtain the total rising time from two adjacent low-level moments to a high-level moment;

[0018] The duty cycle is calculated according to the cycle duration, the high level duration, the low level duration, the total falling duration and the total rising duration, wherein the calculation formula is:

[0019]

[0020] Wherein, Z(B) represents the duty cycle, s(c) represents the total rise time, g(c) represents the high level duration, d(c) represents the low level duration, z(s) represents, and x(c) represents the total fall time;

[0021] Acquire an initial response time and a target steady-state value according to the switching signal waveform diagram, and acquire a stable response time according to the target steady-state value;

[0022] The response duration is acquired according to the stable response time and the initial response time.

[0023] Preferably, the step of respectively obtaining an average output current and an average output voltage according to the current waveform diagram and the voltage waveform diagram, and obtaining an average output power according to the average output voltage and the average output current comprises:

[0024] Get the duty cycle;

[0025] Acquire a peak current according to the current waveform diagram, and acquire an average output current according to the peak current and the duty cycle;

[0026] Acquire a peak voltage according to the voltage waveform diagram, and acquire an average output voltage according to the peak voltage and the duty cycle;

[0027] The average output power is obtained according to the product of the average output voltage and the average output current.

[0028] Preferably, the step of obtaining total harmonic distortion according to the spectrum, and obtaining full-load switching frequency according to the total harmonic distortion, average output power and total period comprises:

[0029] Obtaining the maximum amplitude value of the spectrum as the fundamental wave amplitude;

[0030] Acquire a harmonic order according to the frequency spectrum, and acquire a plurality of harmonic frequencies according to the harmonic order and fundamental wave amplitude;

[0031] According to each of the harmonic frequencies, the closest frequency point is obtained from the frequency axis of the spectrum, and the corresponding harmonic amplitude is obtained according to the frequency point;

[0032] The total harmonic distortion is calculated according to the fundamental wave amplitude and multiple harmonic amplitudes, wherein the calculation formula is:

[0033]

[0034] Among them, Z(X) represents the total harmonic distortion, J(f) represents the fundamental amplitude, and X(F) i represents the i-th harmonic amplitude, i represents the sequence number of the harmonic amplitude, and n represents the number of harmonic amplitudes;

[0035] Get the average output power and total cycle;

[0036] The full load switching frequency is calculated based on the total harmonic distortion, the average output power and the total period, wherein the calculation formula is:

[0037]

[0038] Where Q(P) is the full load switching frequency, Z(T) is the total period, Z(X) is the total harmonic distortion, and P(W) is the average output power.

[0039] Preferably, the step of obtaining the total switching loss according to the full-load switching frequency and the half-load switching frequency, and evaluating the stability performance of the grid-connected energy storage converter according to the total switching loss includes:

[0040] Obtaining full load switching loss according to the full load switching frequency;

[0041] Obtaining a half-load switching loss according to the half-load switching frequency;

[0042] Obtaining a total switch loss according to the full-load switch loss and the half-load switch loss, and obtaining an energy conversion efficiency according to the total switch loss;

[0043] Determining whether the energy conversion efficiency is greater than a preset energy conversion efficiency;

[0044] If the energy conversion efficiency is greater than the preset energy conversion efficiency, it is determined that the stability performance of the grid-type energy storage converter is good;

[0045] If the energy conversion efficiency is not greater than the preset energy conversion efficiency, it is determined that the stability performance of the grid-type energy storage converter is poor.

[0046] Preferably, the step of obtaining the full-load switching loss according to the full-load switching frequency comprises:

[0047] Obtaining the load current and duty cycle of the grid-type energy storage converter under the full load state according to the full load switching frequency;

[0048] Obtaining the on-resistance, on-time, off-time and drain-source voltage of the switch of the grid-type energy storage converter;

[0049] The conduction damage is calculated according to the duty cycle, load current and on-resistance, wherein the calculation formula is:

[0050] D(S)=F(L) 2 *Z(B)*D(R);

[0051] Among them, D(S) represents conduction damage, F(L) represents load current, Z(B) represents duty cycle, and D(R) represents on-resistance;

[0052] The switch damage is calculated based on the drain-source voltage, load current, full load switching frequency, turn-on time and turn-off time, wherein the calculation formula is:

[0053]

[0054] Where K(S) is the switch damage, F(L) is the load current, L(v) is the drain-source voltage, T(D) is the turn-on time, T(G) is the turn-off time, and Q(P) is the full load switching frequency.

[0055] The present application also provides a switching frequency testing system for a grid-type energy storage converter module, comprising:

[0056] A first acquisition module is used to obtain a full-load switch characteristic waveform diagram and a half-load switch characteristic waveform diagram of the grid-type energy storage converter under full-load and half-load states, respectively, wherein the full-load switch characteristic waveform diagram includes a switch signal waveform diagram, a current waveform diagram and a voltage waveform diagram;

[0057] A second acquisition module, used to acquire a duty cycle and a response time according to the switch signal waveform diagram, and acquire a total cycle according to the duty cycle and the response time;

[0058] A third acquisition module, used to respectively acquire an average output current and an average output voltage according to the current waveform diagram and the voltage waveform diagram, and acquire an average output power according to the average output voltage and the average output current;

[0059] A conversion module, used for acquiring a time domain waveform of the switching signal waveform diagram, and converting the time domain waveform into a frequency domain waveform according to Fourier transform to obtain a spectrum;

[0060] A fourth acquisition module, configured to acquire total harmonic distortion according to the frequency spectrum, and acquire full-load switching frequency according to the total harmonic distortion, average output power and total period;

[0061] A fifth acquisition module, configured to acquire a half-load switching frequency according to the half-load switching characteristic waveform diagram;

[0062] An evaluation module is used to obtain the total switching loss according to the full-load switching frequency and the half-load switching frequency, and evaluate the stability performance of the grid-type energy storage converter according to the total switching loss.

[0063] Preferably, the second acquisition module includes:

[0064] A first acquisition unit, used for acquiring a cycle duration according to the switching signal waveform diagram;

[0065] A second acquisition unit is used to acquire a plurality of high-level moments and a plurality of low-level moments within a cycle duration according to the switch signal waveform diagram, and respectively acquire a high-level duration and a low-level duration according to the plurality of high-level moments and the plurality of low-level moments;

[0066] A third acquisition unit is used to acquire a total falling time according to a plurality of adjacent two high-level moments to low-level moments;

[0067] A fourth acquisition unit, used for acquiring a total rising time length according to a plurality of adjacent two low-level moments to a high-level moment;

[0068] A calculation unit is used to calculate the duty cycle according to the cycle duration, the high level duration, the low level duration, the total falling duration and the total rising duration, wherein the calculation formula is:

[0069]

[0070] Wherein, Z(B) represents the duty cycle, s(c) represents the total rise time, g(c) represents the high level duration, d(c) represents the low level duration, z(s) represents, and x(c) represents the total fall time;

[0071] a fifth acquisition unit, configured to acquire an initial response time and a target steady-state value according to the switching signal waveform diagram, and acquire a stable response time according to the target steady-state value;

[0072] A sixth acquisition unit is used to acquire the response duration according to the stable response time and the initial response time.

[0073] The present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the switching frequency testing method of the above-mentioned grid-type energy storage converter module when executing the computer program.

[0074] The present invention also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the switching frequency testing method of the above-mentioned grid-type energy storage converter module are implemented.

[0075] The beneficial effects of the present invention are as follows: by obtaining the switching characteristic waveform diagram of the grid-type energy storage inverter under full load and half load conditions, and obtaining and analyzing the switching signal, current waveform and voltage waveform, the present invention can comprehensively analyze the behavior of the inverter under different load conditions, accurately calculate the duty cycle and response time, and help judge the performance of the switching element under different working conditions. By comparing the full load and half load conditions, the stability and reliability of the grid-type energy storage inverter can be better evaluated. The periodic components and harmonics in the signal can be effectively identified through frequency domain analysis, and the influence of electromagnetic interference and noise on the time domain signal can be reduced. The complex time domain signal can be decomposed into different frequency components through Fourier transform, so that in the presence of interference, it can also The useful signal can be extracted more clearly. The combined use of full-load and half-load switching frequencies can more accurately reflect the switching losses under different load conditions. This method takes into account the switching characteristics under different working conditions and can provide a more realistic loss evaluation. By evaluating the total loss, the operating efficiency and stability of the converter under different loads can be more intuitively understood. The method of obtaining the total switching loss through full-load and half-load switching frequencies can effectively overcome the problem of inaccurate switching frequency measurement caused by electromagnetic interference and noise. It not only improves the accuracy of loss calculation and the effectiveness of stable performance evaluation, but also provides important data support for converter optimization and fault warning, laying the foundation for the reliable operation of grid-connected energy storage converters. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] Figure 1 The figure is a schematic diagram of a method flow according to an embodiment of the present invention.

[0077] Figure 2 FIG. 1 is a schematic diagram of a device structure according to an embodiment of the present invention.

[0078] Figure 3 A schematic diagram of the internal structure of a computer device according to an embodiment of the present application.

[0079] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0080] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0081] like Figure 1-Figure 3 As shown, the present application provides a switching frequency testing method for a grid-type energy storage converter module, comprising:

[0082] S1. Obtaining a full-load switch characteristic waveform diagram and a half-load switch characteristic waveform diagram of the grid-type energy storage converter under full-load and half-load states, respectively, wherein the full-load switch characteristic waveform diagram includes a switch signal waveform diagram, a current waveform diagram, and a voltage waveform diagram;

[0083] S2. Obtaining a duty cycle and a response duration according to the switch signal waveform diagram, and obtaining a total cycle according to the duty cycle and the response duration;

[0084] S3, respectively obtaining an average output current and an average output voltage according to the current waveform diagram and the voltage waveform diagram, and obtaining an average output power according to the average output voltage and the average output current;

[0085] S4, obtaining a time domain waveform of the switch signal waveform diagram, and converting the time domain waveform into a frequency domain waveform according to Fourier transform to obtain a spectrum;

[0086] S5. Obtaining total harmonic distortion according to the frequency spectrum, and obtaining full-load switching frequency according to the total harmonic distortion, average output power and total period;

[0087] S6, obtaining a half-load switching frequency according to the half-load switch characteristic waveform diagram;

[0088] S7. Obtain the total switching loss according to the full-load switching frequency and the half-load switching frequency, and evaluate the stability performance of the grid-connected energy storage converter according to the total switching loss.

[0089] As described in the above steps S1-S7, the grid-type energy storage inverter is a power electronic device used to connect the energy storage system (such as a battery) to the power grid. Its main function is to convert direct current into alternating current to supply the power grid or power load. The grid-type inverter is particularly suitable for renewable energy (such as solar energy, wind energy) integration, microgrid systems and large-scale energy storage systems. Switch testing is the process of evaluating and measuring the performance of switching elements in a grid-type energy storage inverter. In actual testing, the switching signal waveform may be affected by electromagnetic interference, noise, etc., which makes the signal captured by an oscilloscope or spectrum analyzer not clear enough, resulting in inaccurate measurement of the switching frequency. The present invention obtains a full-load switch characteristic waveform diagram and a half-load switch characteristic waveform diagram of a grid-type energy storage converter under full-load and half-load states, respectively, wherein the full-load state refers to the converter operating at its rated power (maximum output capacity), and the full-load switch characteristic waveform diagram refers to a time domain waveform diagram of the converter switch signal recorded under the full-load state, and the half-load state refers to the converter operating at half or nearly half of the rated power, and the half-load switch characteristic waveform diagram refers to a time domain waveform diagram of the converter switch signal recorded under the half-load state, and the full-load switch characteristic waveform diagram includes a switch signal waveform diagram, a current waveform diagram, and a voltage waveform diagram, and then obtains the duty cycle and response duration according to the switch signal waveform diagram, and obtains the total cycle according to the duty cycle and response duration In this way, by obtaining the switching characteristic waveform diagram of the grid-type energy storage converter under full load and half load conditions, and obtaining and analyzing the switching signal, current waveform and voltage waveform, the behavior of the converter under different load conditions can be comprehensively analyzed, and its performance can be fully understood. By comparing and analyzing the waveforms under full load and half load conditions, the duty cycle and response time can be accurately calculated. These parameters directly affect the calculation of the switching frequency and can help determine the performance of the switching elements under different working conditions. The total cycle information obtained can reflect the dynamic response of the converter under different load conditions, which in turn helps to evaluate the stability and consistency of the switching frequency in practical applications. By comparing the full load and half load conditions, the stability and reliability of the grid-type energy storage converter can be better evaluated.

[0090] The average output current and average output voltage are obtained according to the current waveform and voltage waveform respectively, and the average output power is obtained according to the average output voltage and average output current. In this way, by directly calculating the average output current and voltage, the influence of electromagnetic interference and noise on the instantaneous signal waveform can be reduced. When the instantaneous signal is interfered with, the waveform may be distorted, and the calculated average value can better reflect the actual output situation. Since the switching signal waveform is easily affected by electromagnetic interference, direct measurement of the switching frequency may not be accurate enough. By obtaining the average current and voltage, the interference effect in a short period of time can be filtered out to a certain extent, providing a more stable frequency measurement basis. Compared with analyzing the rapidly changing switching waveform, the calculation of the average output current and voltage is usually relatively simple, reducing the dependence on complex algorithms or high-frequency processors, reducing the complexity of the test system, not only improving the accuracy and reliability of the test, but also effectively reducing the influence of electromagnetic interference and noise on the switching frequency measurement. By obtaining the time domain waveform of the switching signal waveform diagram and according to the Fourier transform The time domain waveform is converted into a frequency domain waveform to obtain a spectrum, and then the total harmonic distortion is obtained according to the spectrum, and the full-load switching frequency is obtained according to the total harmonic distortion, average output power and total period. Similarly, the half-load switching frequency is obtained according to the half-load switch characteristic waveform diagram. In this way, the periodic components and harmonics in the signal can be effectively identified through frequency domain analysis, and the influence of electromagnetic interference and noise on the time domain signal can be reduced. The complex time domain signal can be decomposed into different frequency components through Fourier transform, so that the useful signal can be extracted more clearly in the presence of interference. The total harmonic distortion can be directly calculated through the spectrum, which reflects the quality of the switching signal. The spectrum analysis can directly identify the main frequency components, thereby accurately determining the switching frequency, especially in the presence of interference. Compared with simple time domain measurement, this method can provide more reliable frequency information, and frequency domain processing can more flexibly apply filtering and noise reduction technology to improve signal clarity. By removing interference components in the frequency domain, a more accurate signal can be obtained, and the measurement accuracy of the switching frequency can be improved.

[0091] By obtaining the total switching loss based on the full-load switching frequency and the half-load switching frequency, and evaluating the stable performance of the grid-type energy storage converter based on the total switching loss, the combined use of the full-load and half-load switching frequencies can more accurately reflect the switching losses under different load conditions. This method takes into account the switching characteristics under different working conditions and can provide a more realistic loss evaluation. Since the total switching loss is one of the key indicators of converter performance, by evaluating the total loss, the operating efficiency and stability of the converter under different loads can be more intuitively understood. In the case of electromagnetic interference and noise, simply relying on the switching signal waveform for frequency measurement may lead to erroneous results. By calculating the total switching loss, the impact of frequency on system performance can be indirectly reflected, reducing dependence on direct measurement. Compared with real-time analysis of complex and unstable signals with complex waveforms, directly calculating the loss through frequency simplifies the measurement and analysis process. This simplification makes the test process more efficient and repeatable. Therefore, the method of obtaining the total switching loss through full-load and half-load switching frequencies can effectively overcome the problem of inaccurate switching frequency measurement caused by electromagnetic interference and noise. It not only improves the accuracy of loss calculation and the effectiveness of stable performance evaluation, but also provides important data support for converter optimization and fault warning, laying the foundation for the reliable operation of grid-connected energy storage converters.

[0092] In one embodiment, the step S2 of acquiring the duty cycle and the response time according to the switching signal waveform diagram includes:

[0093] S21, obtaining a cycle duration according to the switch signal waveform diagram;

[0094] S22, acquiring a plurality of high-level moments and a plurality of low-level moments within a cycle duration according to the switch signal waveform diagram, and acquiring a high-level duration and a low-level duration respectively according to the plurality of high-level moments and the plurality of low-level moments;

[0095] S23, obtaining a total falling time according to a plurality of adjacent high-level moments to low-level moments;

[0096] S24, obtaining a total rising time from two adjacent low-level moments to a high-level moment;

[0097] S25, calculating the duty cycle according to the cycle duration, the high level duration, the low level duration, the total falling duration and the total rising duration, wherein the calculation formula is:

[0098]

[0099] Wherein, Z(B) represents the duty cycle, s(c) represents the total rise time, g(c) represents the high level duration, d(c) represents the low level duration, z(s) represents, and x(c) represents the total fall time;

[0100] S26, obtaining an initial response time and a target steady-state value according to the switch signal waveform diagram, and obtaining a stable response time according to the target steady-state value;

[0101] S27. Acquire response duration according to the stable response time and the initial response time.

[0102] As described in the above steps S21-S27, the present invention obtains the cycle duration through the switch signal waveform diagram, and obtains multiple high-level moments and multiple low-level moments within the cycle duration according to the switch signal waveform diagram, and then obtains the high-level duration and the low-level duration according to the multiple high-level moments and the multiple low-level moments, respectively, wherein the high-level duration refers to the time length that the signal remains in a high-level state (usually corresponding to the switch-on state) in the waveform of the switch signal, and the low-level duration refers to the time length that the signal remains in a low-level state (usually corresponding to the switch-off state) in the waveform of the switch signal. In this way, by obtaining multiple high-level and low-level moments, the signal waveform can be analyzed more comprehensively to avoid the possibility of single waveform sampling. The error caused by the sampling point can be reduced by averaging, and the influence of noise can be improved. The calculation of the duration of multiple high and low levels can obtain more stable statistical characteristics. The signal fluctuation caused by electromagnetic interference or noise can be effectively smoothed by collecting and calculating multiple data points, thereby reducing the influence of unnecessary interference on the switching frequency measurement. The total falling time is obtained from the time from two adjacent high level moments to the time from the low level, and the total rising time is obtained from the time from two adjacent low level moments to the time from the high level. For example, 1, 6, 11, and 18 are low level moments, and 3, 9, and 15 are high level moments. Then the total falling time obtained from the time from two adjacent high level moments to the time from the low level is 6-3+11-9+18-15= 8. The total rise time obtained from two adjacent low-level moments to a high-level moment is 5-1+9-6+15-11=11. By analyzing multiple adjacent high and low-level moments, the dynamic characteristics of the switching signal can be captured more comprehensively. This method reduces the error that may be caused by measuring a single moment and improves the measurement accuracy of the switching frequency. Through multiple measurements, the waveform mutation caused by electromagnetic interference and noise can be smoothed, making the measurement results of the rise and fall time more reliable. The duty cycle is calculated based on the cycle duration, high-level duration, low-level duration, total fall time and total rise time. In this way, a more accurate duty cycle can be obtained by calculating the cycle duration and the high-level duration. This method can effectively eliminate the error caused by The instantaneous fluctuations caused by electromagnetic interference and noise ensure that the measurement of the duty cycle is more stable and reliable. In a high-noise environment, the clarity of the waveform may be affected. By analyzing multiple time parameters (high-level duration, low-level duration, etc.), the error introduced by a single measurement can be reduced. The method of calculating the duty cycle by cycle duration, high-level duration, low-level duration, total decline duration, and total rise duration can effectively improve the accuracy of the switching frequency test, improve signal quality, enhance the robustness of the system, and support fault diagnosis and early warning. The initial response time and the target steady-state value are obtained according to the switching signal waveform, and the stable response time is obtained according to the target steady-state value. The response time is obtained according to the stable response time and the initial response time.The target steady-state value refers to the stable state value reached by the output signal of a system after a certain period of time. This is the final value of the signal response, and usually represents the constant value that the system tends to after the input signal or initial conditions change. By determining the initial response time and the target steady-state value, it can help to clearly define the change process of the switching signal, making the starting and end points of the response clearer, thereby improving the accuracy of the measurement. By obtaining the initial response time, target steady-state value, stable response time and response duration based on the switching signal waveform, the accuracy and reliability of the switching frequency test can be significantly improved. This method can not only improve the signal analysis capability and enhance the system robustness, but also provide strong support for fault diagnosis, optimization of control strategies and performance improvement, and ultimately ensure the safety and stability of grid-connected energy storage converters in practical applications. ,

[0103] In one embodiment, the step S3 of respectively obtaining the average output current and the average output voltage according to the current waveform diagram and the voltage waveform diagram, and obtaining the average output power according to the average output voltage and the average output current includes:

[0104] S31, obtaining a duty cycle;

[0105] S32, obtaining a peak current according to the current waveform diagram, and obtaining an average output current according to the peak current and the duty cycle;

[0106] S33, obtaining a peak voltage according to the voltage waveform diagram, and obtaining an average output voltage according to the peak voltage and the duty cycle;

[0107] S34. Obtain average output power according to the product of the average output voltage and the average output current.

[0108] As described in the above steps S41-S43, the present invention obtains the peak current and the peak voltage respectively through the current waveform and the voltage waveform, obtains the average output current according to the peak current and the duty cycle, obtains the average output voltage according to the peak voltage and the duty cycle, and then obtains the average output power according to the product of the average output voltage and the average output current. By directly extracting the peak current and the peak voltage from the current and voltage waveforms, the instantaneous fluctuation caused by noise can be avoided, ensuring the accuracy of the measurement data. The steady-state characteristics of the peak current and the peak voltage are used for calculation, which can reduce the influence of electromagnetic interference and noise on the average value calculation, ensuring that the result is more representative. The average output current is calculated by the current and duty cycle, and the average output voltage is calculated by the peak voltage and duty cycle, which provides a clear calculation framework for quickly obtaining stable electrical parameters. The duty cycle, as a control signal, can effectively reflect the regulation of the output power. Using it for average value calculation can adapt to changes under different working conditions. The average output power is obtained by multiplying the average output voltage and the average output current, which can provide accurate power evaluation for the system's energy management and help optimize the working efficiency of the converter, thereby not only improving the measurement accuracy, but also optimizing energy management, supporting system performance analysis, promoting fault diagnosis and enhancing system robustness.

[0109] In one embodiment, the step S5 of acquiring total harmonic distortion according to the spectrum, and acquiring full-load switching frequency according to the total harmonic distortion, average output power and total period includes:

[0110] S51, obtaining the maximum amplitude value of the spectrum as the fundamental wave amplitude;

[0111] S52, obtaining a harmonic order according to the frequency spectrum, and obtaining a plurality of harmonic frequencies according to the harmonic order and fundamental wave amplitude;

[0112] S53, acquiring the closest frequency point on the frequency axis of the spectrum according to each of the harmonic frequencies, and acquiring the corresponding harmonic amplitude according to the frequency point;

[0113] S54, calculating the total harmonic distortion according to the fundamental wave amplitude and multiple harmonic amplitudes, wherein the calculation formula is:

[0114]

[0115] Among them, Z(X) represents the total harmonic distortion, J(F) represents the fundamental amplitude, and X(F) i represents the i-th harmonic amplitude, i represents the sequence number of the harmonic amplitude, and n represents the number of harmonic amplitudes;

[0116] S55, obtaining average output power and total period;

[0117] S56. Calculate the full-load switching frequency according to the total harmonic distortion, the average output power and the total period, wherein the calculation formula is:

[0118]

[0119] Where Q(P) is the full load switching frequency, Z(T) is the total period, Z(X) is the total harmonic distortion, and p(W) is the average output power.

[0120] As described in the above steps S51-S56, the present invention obtains the maximum amplitude value of the spectrum as the fundamental amplitude, obtains the harmonic order according to the spectrum, and obtains multiple harmonic frequencies according to the harmonic order and the fundamental amplitude, wherein the fundamental amplitude refers to the strongest frequency component in the spectrum, which is usually the fundamental frequency of the signal, the harmonic order refers to the frequency component that is an integer multiple of the fundamental frequency, and the harmonic frequency refers to the actual frequency of the harmonic component related to the fundamental frequency, which is equal to the multiple of the fundamental frequency, called the harmonic order multiplied by the fundamental frequency, for example, the second-order harmonic frequency is twice the fundamental frequency, the third-order harmonic frequency is three times the fundamental frequency, and so on. Obtaining the maximum amplitude value from the spectrum as the fundamental amplitude helps to accurately evaluate the main power components of the signal and ensure power calculation. The accuracy of the harmonics can be obtained through spectrum analysis, and then the influence of each order of harmonics can be analyzed. This is very important for evaluating the nonlinear characteristics and harmonic distortion of the system. Harmonic analysis can help identify potential faults in the converter module. For example, abnormal harmonic distribution may indicate component problems or inadequacies in the control strategy. The closest frequency point is obtained from the frequency axis of the spectrum according to each harmonic frequency, and the corresponding harmonic amplitude is obtained according to the frequency point. The closest frequency point is due to the Fourier transform that converts the continuous frequency domain signal into a discrete frequency domain signal. The theoretically calculated harmonic frequency may not completely fall on the actual frequency point in the spectrum. The frequency of each point in the spectrum is fixed, and the interval between these points depends on the sampling frequency and sampling time of the signal. In order to obtain the accurate harmonic amplitude, we need to find the frequency point in the spectrum that is closest to the target harmonic frequency. Suppose we want to extract a specific harmonic frequency, such as the third harmonic, whose theoretical frequency is 3 times the fundamental frequency. If the theoretical third harmonic frequency is 150Hz, but the distribution of frequency points on the spectrum is discrete, for example, it may be between 149.7Hz and 150.3Hz, then the closest frequency point is 150.3Hz, because it is closest to the theoretical frequency of 150Hz. Extracting the harmonic amplitude directly from the spectrum can effectively filter out the influence of interference and noise. Compared with directly analyzing the signal in the time domain, frequency domain analysis helps to improve the signal-to-noise ratio by integrating signals of multiple cycles. By finding the frequency point closest to the harmonic frequency, the actual amplitude of the harmonic can be more accurately identified, thereby improving the reliability of the measurement. Extracting the harmonic amplitude in the spectrum can more clearly display the harmonic distribution caused by nonlinear loads or other devices. The total harmonic distortion is calculated based on the fundamental amplitude and multiple harmonic amplitudes, and then the full load switching frequency is calculated based on the total harmonic distortion, average output power and total cycle.

[0121] In one embodiment, the step S7 of obtaining the total switching loss according to the full-load switching frequency and the half-load switching frequency, and evaluating the stability performance of the grid-connected energy storage converter according to the total switching loss includes:

[0122] S71, obtaining full-load switching loss according to the full-load switching frequency;

[0123] S71, obtaining a half-load switching loss according to the half-load switching frequency;

[0124] S71, obtaining a total switch loss according to the full-load switch loss and the half-load switch loss, and obtaining an energy conversion efficiency according to the total switch loss;

[0125] S71, determining whether the energy conversion efficiency is greater than a preset energy conversion efficiency;

[0126] If the energy conversion efficiency is greater than the preset energy conversion efficiency, it is determined that the stability performance of the grid-type energy storage converter is good;

[0127] If the energy conversion efficiency is not greater than the preset energy conversion efficiency, it is determined that the stability performance of the grid-type energy storage converter is poor.

[0128] As described in the above steps S8-S10, the present invention obtains the full-load switching loss through the full-load switching frequency, obtains the half-load switching loss according to the half-load switching frequency, obtains the total switching loss according to the full-load switching loss and the half-load switching loss, and obtains the energy conversion efficiency according to the total switching loss, specifically by obtaining the output power of the converter, using the formula Among them, N(Z) represents the energy conversion efficiency, S(W) represents the output power of the converter, and Z(K) represents the total switch loss, and the energy conversion efficiency can be calculated. By measuring the switching losses under full load and half load states respectively, the performance of the converter under different working conditions can be more comprehensively reflected, and the error caused by unclear signals can be reduced. The tests of full load and half load states can provide richer data, enhance the understanding of system performance, and help identify the loss characteristics under different load conditions. When measuring the switching losses of full load and half load, spectrum analysis can be used to improve the signal-to-noise ratio, thereby effectively reducing the impact of electromagnetic interference on the measurement results. By combining the switching losses of full load and half load, the total switch loss can be more accurately evaluated to avoid the error influence under a single load condition. By accurately calculating the total switch loss, the energy conversion efficiency can be more truly reflected to ensure that the operating efficiency of the system under different loads is fully evaluated. Then, by judging whether the energy conversion efficiency is greater than the preset energy conversion efficiency, if the energy conversion efficiency is greater than the preset energy conversion efficiency, it is determined that the stability performance of the grid-type energy storage converter is good, otherwise it is determined that the stability performance of the grid-type energy storage converter is poor.

[0129] In one embodiment, the step of obtaining the full-load switching loss according to the full-load switching frequency includes:

[0130] Obtaining the load current and duty cycle of the grid-type energy storage converter under the full load state according to the full load switching frequency;

[0131] Obtaining the on-resistance, on-time, off-time and drain-source voltage of the switch of the grid-type energy storage converter;

[0132] The conduction damage is calculated according to the duty cycle, load current and on-resistance, wherein the calculation formula is:

[0133] D(S)=F(L) 2 *Z(B)*D(R);

[0134] Among them, D(S) represents conduction damage, F(L) represents load current, Z(B) represents duty cycle, and D(R) represents on-resistance;

[0135] The switch damage is calculated based on the drain-source voltage, load current, full load switching frequency, turn-on time and turn-off time, wherein the calculation formula is:

[0136]

[0137] Where K(S) represents switch damage, F(L) represents load current, L(V) represents drain-source voltage, T(D) represents turn-on time, T(G) represents turn-off time, and Q(P) represents full load switching frequency.

[0138] As described in the above steps S101-S103, the present invention obtains the load current and duty cycle of the grid-type energy storage converter under the full load state through the full load switching frequency, obtains the on-resistance, on-time, off-time and drain-source voltage of the switch of the grid-type energy storage converter, calculates the on-damage according to the duty cycle, load current and on-resistance, and calculates the switch damage according to the drain-source voltage, load current, full load switching frequency, on-time and off-time. In this way, by directly measuring the load current and duty cycle, the dependence on the switching frequency measurement can be fundamentally reduced, thereby reducing the influence of noise and electromagnetic interference on the results, and combining multiple parameters (such as on-resistance, on-time, etc.) for comprehensive calculation. It can more comprehensively reflect the switching performance and enhance the reliability of the results. According to the duty cycle, load current and on-resistance, the calculation of conduction loss can provide more accurate loss data, which is crucial for evaluating the efficiency of the converter. The load current and duty cycle are obtained through the full-load switching frequency, and the conduction loss and switching loss are calculated by combining the on-resistance, on-time, off-time and drain-source voltage. This method can effectively solve the problem of unclear signals in the switching frequency test of the grid-type energy storage converter module. This method improves the measurement accuracy, optimizes the loss calculation, enhances the system performance monitoring, supports the design optimization, and simplifies the test process, thereby providing strong support for the performance evaluation and optimization design of the converter.

[0139] The present application also provides a switching frequency testing system for a grid-type energy storage converter module, comprising:

[0140] A first acquisition module is used to obtain a full-load switch characteristic waveform diagram and a half-load switch characteristic waveform diagram of the grid-type energy storage converter under full-load and half-load states, respectively, wherein the full-load switch characteristic waveform diagram includes a switch signal waveform diagram, a current waveform diagram and a voltage waveform diagram;

[0141] A second acquisition module, used to acquire a duty cycle and a response time according to the switch signal waveform diagram, and acquire a total cycle according to the duty cycle and the response time;

[0142] A third acquisition module, used to respectively acquire an average output current and an average output voltage according to the current waveform diagram and the voltage waveform diagram, and acquire an average output power according to the average output voltage and the average output current;

[0143] A conversion module, used for acquiring a time domain waveform of the switching signal waveform diagram, and converting the time domain waveform into a frequency domain waveform according to Fourier transform to obtain a spectrum;

[0144] A fourth acquisition module, configured to acquire total harmonic distortion according to the frequency spectrum, and acquire full-load switching frequency according to the total harmonic distortion, average output power and total period;

[0145] A fifth acquisition module, configured to acquire a half-load switching frequency according to the half-load switching characteristic waveform diagram;

[0146] An evaluation module is used to obtain the total switching loss according to the full-load switching frequency and the half-load switching frequency, and evaluate the stability performance of the grid-type energy storage converter according to the total switching loss.

[0147] In one embodiment, the second acquisition module includes:

[0148] A first acquisition unit, used for acquiring a cycle duration according to the switching signal waveform diagram;

[0149] A second acquisition unit is used to acquire a plurality of high-level moments and a plurality of low-level moments within a cycle duration according to the switch signal waveform diagram, and respectively acquire a high-level duration and a low-level duration according to the plurality of high-level moments and the plurality of low-level moments;

[0150] A third acquisition unit is used to acquire a total falling time according to a plurality of adjacent two high-level moments to low-level moments;

[0151] A fourth acquisition unit, used for acquiring a total rising time length according to a plurality of adjacent two low-level moments to a high-level moment;

[0152] A calculation unit is used to calculate the duty cycle according to the cycle duration, the high level duration, the low level duration, the total falling duration and the total rising duration, wherein the calculation formula is:

[0153]

[0154] Wherein, Z(B) represents the duty cycle, s(c) represents the total rise time, g(c) represents the high level duration, d(c) represents the low level duration, z(s) represents, and x(c) represents the total fall time;

[0155] a fifth acquisition unit, configured to acquire an initial response time and a target steady-state value according to the switching signal waveform diagram, and acquire a stable response time according to the target steady-state value;

[0156] A sixth acquisition unit is used to acquire the response duration according to the stable response time and the initial response time.

[0157] The present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the switching frequency testing method of the above-mentioned grid-type energy storage converter module when executing the computer program.

[0158] The present invention also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the switching frequency testing method of the above-mentioned grid-type energy storage converter module are implemented.

[0159] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing related hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media provided in this application and used in the embodiments may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (SSRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0160] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, device, article or method including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, device, article or method. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the presence of other identical elements in the process, device, article or method including the element.

[0161] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A switching frequency testing method for a grid-type energy storage converter module, characterized in that: include: Obtaining a full-load switch characteristic waveform diagram and a half-load switch characteristic waveform diagram of the grid-type energy storage converter under full-load and half-load states, respectively, wherein the full-load switch characteristic waveform diagram includes a switch signal waveform diagram, a current waveform diagram, and a voltage waveform diagram; Obtaining a duty cycle and a response duration according to the switch signal waveform diagram, and obtaining a total cycle according to the duty cycle and the response duration; Obtaining an average output current and an average output voltage according to the current waveform diagram and the voltage waveform diagram, respectively, and obtaining an average output power according to the average output voltage and the average output current; Acquire a time domain waveform of the switch signal waveform diagram, and convert the time domain waveform into a frequency domain waveform according to Fourier transform to obtain a frequency spectrum; Obtaining total harmonic distortion according to the frequency spectrum, and obtaining full-load switching frequency according to the total harmonic distortion, average output power and total period; Acquire a half-load switching frequency according to the half-load switching characteristic waveform diagram; The total switching loss is obtained according to the full-load switching frequency and the half-load switching frequency, and the stability performance of the grid-type energy storage converter is evaluated according to the total switching loss.

2. The switching frequency testing method of the grid-type energy storage converter module according to claim 1 is characterized in that: The step of acquiring the duty cycle and the response time according to the switching signal waveform diagram comprises: Acquire the cycle duration according to the switching signal waveform diagram; Acquire multiple high-level moments and multiple low-level moments within the cycle duration according to the switch signal waveform diagram, and respectively acquire the high-level duration and the low-level duration according to the multiple high-level moments and the multiple low-level moments; Obtain the total falling time from two adjacent high-level moments to low-level moments; Obtain the total rising time from two adjacent low-level moments to a high-level moment; The duty cycle is calculated according to the cycle duration, the high level duration, the low level duration, the total falling duration and the total rising duration, wherein the calculation formula is: Wherein, Z(B) represents the duty cycle, s(c) represents the total rise time, g(c) represents the high level duration, d(c) represents the low level duration, z(s) represents, and x(c) represents the total fall time; Acquire an initial response time and a target steady-state value according to the switching signal waveform diagram, and acquire a stable response time according to the target steady-state value; The response duration is acquired according to the stable response time and the initial response time.

3. The switching frequency testing method of the grid-type energy storage converter module according to claim 1 is characterized in that: The step of respectively obtaining an average output current and an average output voltage according to the current waveform diagram and the voltage waveform diagram, and obtaining an average output power according to the average output voltage and the average output current comprises: Get the duty cycle; Acquire a peak current according to the current waveform diagram, and acquire an average output current according to the peak current and the duty cycle; Acquire a peak voltage according to the voltage waveform diagram, and acquire an average output voltage according to the peak voltage and the duty cycle; The average output power is obtained according to the product of the average output voltage and the average output current.

4. The switching frequency testing method of the grid-type energy storage converter module according to claim 1 is characterized in that: The step of obtaining total harmonic distortion according to the spectrum, and obtaining full-load switching frequency according to the total harmonic distortion, average output power and total period includes: Obtaining the maximum amplitude value of the spectrum as the fundamental wave amplitude; Acquire a harmonic order according to the frequency spectrum, and acquire a plurality of harmonic frequencies according to the harmonic order and fundamental wave amplitude; According to each of the harmonic frequencies, the closest frequency point is obtained from the frequency axis of the spectrum, and the corresponding harmonic amplitude is obtained according to the frequency point; The total harmonic distortion is calculated according to the fundamental wave amplitude and multiple harmonic amplitudes, wherein the calculation formula is: Among them, Z(X) represents the total harmonic distortion, J(F) represents the fundamental amplitude, and X(F) i represents the i-th harmonic amplitude, i represents the sequence number of the harmonic amplitude, and n represents the number of harmonic amplitudes; Get the average output power and total cycle; The full load switching frequency is calculated based on the total harmonic distortion, the average output power and the total period, wherein the calculation formula is: Where Q(P) is the full load switching frequency, Z(T) is the total period, Z(X) is the total harmonic distortion, and P(W) is the average output power.

5. The switching frequency testing method of the grid-type energy storage converter module according to claim 1, characterized in that: The step of obtaining the total switching loss according to the full-load switching frequency and the half-load switching frequency, and evaluating the stability performance of the grid-type energy storage converter according to the total switching loss includes: Obtaining full load switching loss according to the full load switching frequency; Obtaining a half-load switching loss according to the half-load switching frequency; Obtaining a total switch loss according to the full-load switch loss and the half-load switch loss, and obtaining an energy conversion efficiency according to the total switch loss; Determining whether the energy conversion efficiency is greater than a preset energy conversion efficiency; If the energy conversion efficiency is greater than the preset energy conversion efficiency, it is determined that the stability performance of the grid-type energy storage converter is good; If the energy conversion efficiency is not greater than the preset energy conversion efficiency, it is determined that the stability performance of the grid-type energy storage converter is poor.

6. The switching frequency testing method of the grid-type energy storage converter module according to claim 5 is characterized in that: The step of obtaining the full-load switching loss according to the full-load switching frequency comprises: Obtaining the load current and duty cycle of the grid-type energy storage converter under the full load state according to the full load switching frequency; Obtaining the on-resistance, on-time, off-time and drain-source voltage of the switch of the grid-type energy storage converter; The conduction damage is calculated according to the duty cycle, load current and on-resistance, wherein the calculation formula is: D(S)=F(L) 2 *Z(B)*D(R); Among them, D(S) represents conduction damage, F(L) represents load current, Z(B) represents duty cycle, and D(R) represents on-resistance; The switch damage is calculated based on the drain-source voltage, load current, full load switching frequency, turn-on time and turn-off time, wherein the calculation formula is: Where K(S) represents switch damage, F(L) represents load current, L(V) represents drain-source voltage, T(D) represents turn-on time, T(G) represents turn-off time, and Q(P) represents full load switching frequency.

7. A switching frequency test system for a grid-type energy storage converter module, characterized in that: include: A first acquisition module is used to obtain a full-load switch characteristic waveform diagram and a half-load switch characteristic waveform diagram of the grid-type energy storage converter under full-load and half-load states, respectively, wherein the full-load switch characteristic waveform diagram includes a switch signal waveform diagram, a current waveform diagram and a voltage waveform diagram; A second acquisition module, used to acquire a duty cycle and a response time according to the switch signal waveform diagram, and acquire a total cycle according to the duty cycle and the response time; A third acquisition module, used to respectively acquire an average output current and an average output voltage according to the current waveform diagram and the voltage waveform diagram, and acquire an average output power according to the average output voltage and the average output current; A conversion module, used for acquiring a time domain waveform of the switch signal waveform diagram, and converting the time domain waveform into a frequency domain waveform according to Fourier transform to obtain a spectrum; A fourth acquisition module, configured to acquire total harmonic distortion according to the frequency spectrum, and acquire full-load switching frequency according to the total harmonic distortion, average output power and total period; A fifth acquisition module, configured to acquire a half-load switching frequency according to the half-load switching characteristic waveform diagram; An evaluation module is used to obtain the total switching loss according to the full-load switching frequency and the half-load switching frequency, and evaluate the stability performance of the grid-type energy storage converter according to the total switching loss.

8. The switching frequency test system of the grid-type energy storage converter module according to claim 7, characterized in that: The second acquisition module includes: A first acquisition unit, used for acquiring a cycle duration according to the switching signal waveform diagram; A second acquisition unit is used to acquire a plurality of high-level moments and a plurality of low-level moments within a cycle duration according to the switch signal waveform diagram, and respectively acquire a high-level duration and a low-level duration according to the plurality of high-level moments and the plurality of low-level moments; A third acquisition unit is used to acquire a total falling time according to a plurality of adjacent two high-level moments to low-level moments; A fourth acquisition unit, used for acquiring a total rising time length according to a plurality of adjacent two low-level moments to a high-level moment; A calculation unit is used to calculate the duty cycle according to the cycle duration, the high level duration, the low level duration, the total falling duration and the total rising duration, wherein the calculation formula is: Wherein, Z(B) represents the duty cycle, s(c) represents the total rise time, g(c) represents the high level duration, d(c) represents the low level duration, z(s) represents, and x(c) represents the total fall time; a fifth acquisition unit, configured to acquire an initial response time and a target steady-state value according to the switching signal waveform diagram, and acquire a stable response time according to the target steady-state value; A sixth acquisition unit is used to acquire the response duration according to the stable response time and the initial response time.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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