Power supply test system and method

Abstract

The invention relates to a power supply testing system and method, and belongs to the technical field of electric power testing, and the power supply testing system comprises a programmable load which is connected with three phases of a power supply to be tested to form a closed loop; the voltage sensor is used for measuring a three-phase voltage signal of the power supply to be measured; the current sensor is used for measuring an A-phase current signal of the power supply to be measured; the universal meter is used for sampling the three-phase voltage signal and the A-phase current signal to obtain sampling data; the upper computer is used for controlling the programmable load with a first preset logic within a first time period and determining a static output index of the power supply to be tested, and controlling the programmable load with a second preset logic within a second time period and determining a dynamic output index of the power supply to be tested, the first preset logic being progressive increase and progressive decrease of the load; the second preset logic is alternately switched between no load and full load. According to the invention, the measurement cost of the output index of the three-phase power supply device is effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of power testing technology, and in particular to a power supply testing system and method. Background Technology

[0002] In scientific research, production and other activities, it is often necessary to measure the output indicators of three-phase power supply devices, such as steady-state voltage regulation rate, steady-state frequency regulation rate, voltage fluctuation rate, frequency fluctuation rate (the above are called the four static items), transient voltage regulation rate, transient frequency regulation rate, voltage stabilization time, frequency stabilization time (the above are called the four dynamic items).

[0003] Currently, dedicated generator set test cabinets used for testing the four static and four dynamic indicators are expensive, bulky, and heavy, resulting in high measurement costs for the output indicators of three-phase power supply units. Therefore, reducing the measurement cost of the output indicators of three-phase power supply units has become an urgent technical problem to be solved. Summary of the Invention

[0004] In view of this, it is necessary to provide a power supply testing system and method to solve the problem of high measurement cost of output parameters of existing three-phase power supply devices.

[0005] To address the aforementioned problems, in a first aspect, the present invention provides a power supply testing system, comprising: A programmable load, connected to the three phases of the power supply under test to form a closed loop; Voltage sensor, used to measure the three-phase voltage signal of the power supply under test; A current sensor is used to measure the A-phase current signal of the power supply under test. A multimeter is used to sample three-phase voltage signals and A-phase current signals to obtain sampled data. The host computer is used to control the programmable load according to a first preset logic within a first time period, acquire first sampling data from a multimeter, acquire a first voltage signal from a voltage sensor and determine the voltage signal frequency, and determine the static output index of the power supply under test based on the first sampling data and the frequency of the first voltage signal. Within a second time period, the host computer controls the programmable load according to a second preset logic, acquires second sampling data from a multimeter, acquires a second voltage signal from a voltage sensor and determines the voltage signal frequency, and determines the dynamic output index of the power supply under test based on the second sampling data and the frequency of the second voltage signal. The first preset logic involves increasing and decreasing the load, and the second preset logic involves alternating between no-load and full-load operation. In one possible implementation, The programmable load is a three-phase programmable RLC load with YN wiring; The static output parameters of the power supply under test include steady-state voltage regulation, steady-state frequency regulation, voltage fluctuation rate, and frequency fluctuation rate. The dynamic output parameters of the power supply under test include transient voltage regulation, transient frequency regulation, voltage settling time, and frequency settling time.

[0006] On the other hand, the present invention also provides a power supply testing method based on the above-described power supply testing system, comprising: Within a first time period, the programmable load is controlled by a first preset logic, and the static output parameters of the power supply under test are determined based on the first sequence, the second sequence, the third sequence, the fourth sequence, and the fifth sequence. Within the second time period, the programmable load is controlled by the second preset logic, and the dynamic output index of the power supply under test is determined based on the sixth, seventh, eighth, ninth and tenth sequences. Wherein, the first sequence is the effective voltage time sequence of phase A of the power supply under test within a first time period, the second sequence is the effective voltage time sequence of phase B of the power supply under test within a first time period, the third sequence is the effective voltage time sequence of phase C of the power supply under test within a first time period, the fourth sequence is the effective current time sequence of phase A of the power supply under test within a first time period, the fifth sequence is the voltage frequency time sequence of phase A of the power supply under test within a first time period, the sixth sequence is the effective voltage time sequence of phase A of the power supply under test within a second time period, the seventh sequence is the effective voltage time sequence of phase B of the power supply under test within a second time period, the eighth sequence is the effective voltage time sequence of phase C of the power supply under test within a second time period, the ninth sequence is the effective current time sequence of phase A of the power supply under test within a second time period, and the tenth sequence is the voltage frequency time sequence of phase A of the power supply under test within a second time period. The first preset logic is the increase and decrease of the load, and the second preset logic is the alternation of no-load and full-load.

[0007] In one possible implementation, determining the static output parameters of the power supply under test based on the first sequence, second sequence, third sequence, fourth sequence, and fifth sequence includes: The fourth sequence is normalized based on the rated output current of the power supply under test, and wavelet decomposition is performed on the normalized fourth sequence. The time points in the wavelet decomposition result where the absolute value of the amplitude of the low-frequency wavelet coefficients is greater than a preset value are determined as the first load change time point sequence. The eleventh sequence is determined based on the first sequence, the second sequence, the third sequence, and the maximum attenuation ratio of the voltage sensor. The eleventh sequence is the time series of the average three-phase line voltage of the power supply under test within the first time period. The static output parameters of the power supply under test are determined based on the first load change time point sequence, the fifth sequence, and the eleventh sequence.

[0008] In one possible implementation, determining the static output parameters of the power supply under test based on the first load change time point sequence, the fifth sequence, and the eleventh sequence includes: Based on the first load change time point sequence, the fifth sequence and the eleventh sequence are divided into multiple segments; Determine the maximum and minimum values ​​in the fifth sequence after segmentation, and the maximum and minimum values ​​in the eleventh sequence after segmentation; Based on the maximum and minimum values ​​in the fifth sequence after segmentation, and the maximum and minimum values ​​in the eleventh sequence after segmentation, the static output parameters of the power supply under test are determined.

[0009] In one possible implementation, determining the static output parameters of the power supply under test based on the maximum and minimum values ​​in the segmented fifth sequence and the maximum and minimum values ​​in the segmented eleventh sequence includes: Based on the maximum and minimum values ​​in the segmented fifth sequence and the frequency of the power supply under test, the steady-state frequency regulation rate and frequency fluctuation rate of the power supply under test are determined. Based on the maximum and minimum values ​​in the segmented eleventh sequence and the rated output voltage of the power supply under test, the steady-state voltage regulation and voltage fluctuation rate of the power supply under test are determined.

[0010] In one possible implementation, determining the dynamic output parameters of the power supply under test based on the sixth, seventh, eighth, ninth, and tenth sequences includes: The ninth sequence is normalized based on the rated output current of the power supply under test, and the normalized fourth sequence is decomposed by wavelet decomposition. The time points in the wavelet decomposition result where the absolute value of the amplitude of the low-frequency wavelet coefficients is greater than a preset value are determined as the second load change time point sequence. The twelfth sequence is determined based on the sixth sequence, the seventh sequence, the eighth sequence, and the maximum attenuation ratio of the voltage sensor. The twelfth sequence is the time series of the average three-phase line voltage of the power supply under test within the second time period. The dynamic output parameters of the power supply under test are determined based on the second load change time point sequence, the tenth sequence, and the twelfth sequence.

[0011] In one possible implementation, determining the dynamic output parameters of the power supply under test based on the second load change time point sequence, the tenth sequence, and the twelfth sequence includes: The tenth and twelfth sequences are divided into multiple segments based on the second load change time point sequence; The frequency-stable time point sequence is determined in the segmented tenth sequence based on a sliding window of a preset length, and the voltage-stable time point sequence is determined in the segmented twelfth sequence based on a sliding window of a preset length. Multiple frequency stable time periods are determined based on the frequency stable time point sequence and the second load change time point sequence; Multiple voltage stabilization time periods are determined based on the voltage stabilization time point sequence and the second load change time point sequence; The dynamic output parameters of the power supply under test are determined based on the multiple frequency stable time periods, the multiple voltage stable time periods, the tenth sequence, and the twelfth sequence.

[0012] In one possible implementation, the plurality of frequency stabilization time periods, the plurality of voltage stabilization time periods, the tenth sequence, and the twelfth sequence determine the dynamic output parameters of the power supply under test, including: The maximum duration among the plurality of frequency stabilization time periods is determined as the frequency stabilization time, and the maximum duration among the plurality of voltage stabilization time periods is determined as the voltage stabilization time. Based on the maximum and minimum values ​​corresponding to the multiple frequency stable time periods in the tenth sequence, the transient frequency regulation rate of the power supply under test is determined; The transient voltage regulation of the power supply under test is determined based on the maximum and minimum values ​​corresponding to the multiple voltage stability time periods in the twelfth sequence.

[0013] In one possible implementation, the sliding window of a preset length determines the frequency-stable time point sequence in the segmented tenth sequence, including: If the difference between the maximum and minimum values ​​within the sliding window is less than or equal to the difference between the maximum and minimum values ​​within each segment of the tenth sequence after segmentation, the time point corresponding to the starting data point of the sliding window is determined as the frequency stable time point. The sliding window based on a preset length determines the voltage stabilization time point sequence in the segmented twelfth sequence, including: If the difference between the maximum and minimum values ​​within the sliding window is less than or equal to the difference between the maximum and minimum values ​​within each segment of the twelfth sequence after segmentation, the time point corresponding to the starting data point of the sliding window is determined as the voltage stabilization time point.

[0014] The beneficial effects of this invention are as follows: The power supply testing system and method provided by this invention can test the performance indicators of the power supply under test through a programmable load, a host computer, and a multimeter. Only a test circuit needs to be built to construct the test system. The size of the test circuit is much smaller than that of existing dedicated generator set test cabinets, thereby reducing the space occupied by the test system. At the same time, the programmable load, host computer, and multimeter can all be carried by the test personnel, thereby reducing the transportation cost of the test. Moreover, the purchase cost of the programmable load, host computer, and multimeter is also much lower than that of dedicated generator set test cabinets, that is, reducing the equipment cost of the test system. This invention effectively reduces the measurement cost of the output performance indicators of three-phase power supply devices. Attached Figure Description

[0015] Figure 1 A schematic diagram of an embodiment of the power supply testing system provided by the present invention; Figure 2 This is a schematic flowchart of an embodiment of the power supply testing method provided by the present invention; Figure 3 An embodiment of the static index test load curve provided by the present invention is intended; Figure 4 This is an embodiment of the dynamic index test load curve provided by the present invention. Detailed Implementation

[0016] 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 a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0017] In the description of the embodiments of the present invention, unless otherwise stated, "multiple" means two or more. "And / or" describes the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0018] The terms "first," "second," etc., used in the embodiments of this invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a technical feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature.

[0019] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0020] This invention provides a power supply testing system and method, which will be described below.

[0021] Figure 1 This is a schematic flowchart of an embodiment of the power supply testing system provided by the present invention, as shown below. Figure 1 As shown, the power supply testing system includes: A programmable load, connected to the three phases of the power supply under test to form a closed loop; Voltage sensor, used to measure the three-phase voltage signal of the power supply under test; A current sensor is used to measure the A-phase current signal of the power supply under test. A multimeter is used to sample three-phase voltage signals and A-phase current signals to obtain sampled data. The host computer is used to control the programmable load with a first preset logic within a first time period, acquire first sampling data from a multimeter, acquire a first voltage signal from a voltage sensor and determine the voltage signal frequency, determine the static output index of the power supply under test based on the first sampling data and the frequency of the first voltage signal, and control the programmable load with a second preset logic within a second time period, acquire second sampling data from a multimeter, acquire a second voltage signal from a voltage sensor and determine the voltage signal frequency, determine the dynamic output index of the power supply under test based on the second sampling data and the frequency of the second voltage signal. The first preset logic is the increase and decrease of the load, and the second preset logic is the alternating switching between no-load and full-load.

[0022] It should be noted that the load can be a three-phase programmable RLC load with an internal YN wiring configuration. The R load is implemented using air-cooled resistance wire, the L load is implemented using a high-power wire-wound iron core inductor, and the C load is implemented using a self-healing low-voltage reactive power compensation capacitor with a withstand voltage of not less than 450V. The operating phase voltage range of the load is within AC 90V~440V and the frequency is within 45Hz~440Hz. Each phase R load should not exceed 100kW, L load should not exceed 100kvar, and C load should not exceed 100kvar. Electromagnetic contactors are used for shifting, with a minimum step of not more than 100W / 100var. The load is connected to the host computer via a communication line using the RS 485 Modbus protocol. It can add or remove loads according to commands issued by the host computer and simultaneously upload three-phase phase voltage, line voltage, phase current, and power factor at a rate of not less than 1S / s.

[0023] The multimeter can be a large benchtop multimeter with a scanning board, characterized by the following features: the scanning board can connect to no less than 5 voltage circuits, the maximum input voltage is no less than 100V DC or AC RMS, the input bandwidth is no less than 10kHz, and there is electrical isolation between the voltage circuits of the scanning board; the multimeter itself has a sampling rate of no less than 100S / s when measuring AC, the direct input voltage measurement range is no less than 1mV~600V, and the display has no less than 5.5 digits. The multimeter is connected to a host computer via a communication cable, and the communication interface is GPIB or USB 2.0.

[0024] The host computer can be a laptop.

[0025] The voltage sensor is a high-voltage differential voltage probe with a maximum input voltage of not less than 1400V peak-to-peak, a probe bandwidth of not less than 20MHz, an output noise of not more than 20mV, a maximum attenuation ratio (kPT) of not less than 100, a measurement accuracy of not less than 2%, and an output interface with a BNC male connector. The voltage sensor is connected sequentially to measure UAB, UBC, and UCA, and then connected to the multimeter scanning board using a BNC female connector and a 50Ω coaxial cable. The three-phase voltage sensors are connected sequentially to channels 1 to 3 of the scanning board, while the A-phase voltage sensor is also connected to channel 5 of the scanning board.

[0026] The current sensor can be a Rokowski coil, electromagnetic current transformer, closed-loop Hall sensor, or TMR sensor. The current measurement limit is no less than 200A, the bandwidth is no less than 1kHz, the output ratio is no less than 10mV / A, the measurement accuracy is no less than 2%, and the output interface is a BNC male connector with pins. The current sensor measures the amplitude of phase A current and is connected to channel 4 of the multimeter scanning board using a BNC female connector and a 50Ω coaxial cable. The host computer software can be developed based on QT or LabVIEW.

[0027] During power supply testing, the host computer can adjust the programmable load according to preset control logic, and then determine the static and dynamic indicators of the power supply under test based on the acquired data.

[0028] In summary, the power supply testing system provided by this invention uses a programmable load, a host computer, and a multimeter to test the performance indicators of the power supply under test. Only a test circuit needs to be built to construct the system, and the size of the test circuit is much smaller than existing dedicated generator set test cabinets, thus reducing the space occupied by the testing system. Furthermore, the programmable load, host computer, and multimeter can all be carried by the testing personnel, reducing transportation costs. The purchase cost of the programmable load, host computer, and multimeter is also much lower than that of dedicated generator set test cabinets, thus reducing the equipment cost of the testing system. This invention effectively reduces the cost of measuring the output performance indicators of three-phase power supply devices.

[0029] Figure 2 This is a schematic flowchart of an embodiment of the power supply testing method provided by the present invention. The method is implemented based on the above-described power supply testing system, such as... Figure 2 As shown, the power supply testing methods include: S201. Within a first time period, the programmable load is controlled by a first preset logic, and the static output parameters of the power supply under test are determined based on the first sequence, the second sequence, the third sequence, the fourth sequence, and the fifth sequence.

[0030] S202. Within the second time period, the programmable load is controlled by the second preset logic, and the dynamic output index of the power supply under test is determined based on the sixth sequence, the seventh sequence, the eighth sequence, the ninth sequence, and the tenth sequence.

[0031] Wherein, the first sequence is the effective voltage time sequence of phase A of the power supply under test within a first time period, the second sequence is the effective voltage time sequence of phase B of the power supply under test within a first time period, the third sequence is the effective voltage time sequence of phase C of the power supply under test within a first time period, the fourth sequence is the effective current time sequence of phase A of the power supply under test within a first time period, the fifth sequence is the voltage frequency time sequence of phase A of the power supply under test within a first time period, the sixth sequence is the effective voltage time sequence of phase A of the power supply under test within a second time period, the seventh sequence is the effective voltage time sequence of phase B of the power supply under test within a second time period, the eighth sequence is the effective voltage time sequence of phase C of the power supply under test within a second time period, the ninth sequence is the effective current time sequence of phase A of the power supply under test within a second time period, and the tenth sequence is the voltage frequency time sequence of phase A of the power supply under test within a second time period. The first preset logic is the increase and decrease of the load, and the second preset logic is the alternation of no-load and full-load.

[0032] Specifically, the first step is to determine the rated output voltage of the power supply under test. ,frequency Active power and power factor Determine the active power required for each phase of the load. and reactive power Then load control is performed.

[0033] Combination Figure 3 In the first preset logic, let T0 be the start time of the static four-phase load loading. Then, within the time period [T0, T0+120s), the active and reactive power of each phase load are both 0, and within the time period [T0+120s, T0+240s), the active power of each phase load is... Reactive power is During the time period [T0+240s, T0+360s), the active and reactive power of each phase load are both 0, and during the time period [T0+360s, T0+480s), the active power of each phase load is 25%. Reactive power is 25%. During the time period [T0+480s, T0+600s), the active power of each phase load is 50%. Reactive power is 50%. During the time period [T0+600s, T0+720s), the active power of each phase load is 75%. The reactive power is 75%. During the time period [T0+720s, T0+840s), the active power of each phase load is 100%. Reactive power is 100%. Then, the load is reduced sequentially according to the above loading steps, with each step duration remaining at 120 seconds.

[0034] Combination Figure 4 Let's look at the second preset logic. Let T1 be the start time of the dynamic four-phase load loading. Then, with a time interval of 60 seconds, this will be repeated six times at full load (the active power of each phase load is...). Reactive power is Switching between load and no-load states.

[0035] During static performance testing, the host computer controls the load to be added or removed via a communication line. Simultaneously, it controls a multimeter to synchronously record the voltage measurement results of channels 1 through 4 at a sampling rate of 1-2 seconds per second, sequentially forming voltage RMS value-time series CHNL_S_1 to CHNL_S_4 (i.e., the first to fourth series) and storing them as .csv files. Simultaneously, it also synchronously records the voltage signal frequency measurement results of channel 5, forming a frequency-time series CHNL_S_5 (i.e., the fifth series) and storing it as a .csv file. The voltage, current, active power, and reactive power of each phase uploaded by the load are also recorded. Then, static performance calculations are performed.

[0036] During dynamic performance testing, loads are added and removed based on the load values ​​and loading curves for each phase. Measurements are recorded at the maximum achievable sampling rate, forming voltage RMS value-time series CHNL_D_1~CHNL_D_4 (i.e., the sixth to ninth series), and stored as a .csv file. Simultaneously, the voltage signal frequency measurement results from channel 5 are also recorded, forming a frequency-time series CHNL_D_5 (i.e., the tenth series), and stored as a .csv file. The voltage, current, active power, and reactive power of each phase uploaded by load 1 are also recorded. Dynamic performance is then calculated.

[0037] In summary, the voltage testing method provided by the embodiments of the present invention achieves static and dynamic performance testing of power supplies by controlling a programmable load, effectively reducing the measurement cost of output performance of three-phase power supply devices.

[0038] In some embodiments of the present invention, determining the static output parameters of the power supply under test based on the first sequence, second sequence, third sequence, fourth sequence, and fifth sequence includes: The fourth sequence is normalized based on the rated output current of the power supply under test, and wavelet decomposition is performed on the normalized fourth sequence. The time points in the wavelet decomposition result where the absolute value of the amplitude of the low-frequency wavelet coefficients is greater than a preset value are determined as the first load change time point sequence. The eleventh sequence is determined based on the first sequence, the second sequence, the third sequence, and the maximum attenuation ratio of the voltage sensor. The eleventh sequence is the time series of the average three-phase line voltage of the power supply under test within the first time period. The static output parameters of the power supply under test are determined based on the first load change time point sequence, the fifth sequence, and the eleventh sequence.

[0039] Specifically, firstly, based on the rated output voltage of the input power supply under test... Active power and power factor Calculate the rated output current :

[0040] Next, calculate the normalized effective value of phase A current - time series IS_Pu using the following formula:

[0041] Then, the IS_Pu is decomposed into three levels using Haar wavelets. The absolute value of the amplitude of the low-frequency wavelet coefficients at scale 3 is measured point by point. Points with an absolute value of amplitude greater than 0.05 are the time points of load change.

[0042] The measurement data is then preprocessed. The mean three-phase line voltage time series U_SAV is calculated as follows:

[0043] The effective value of the load phase A current - time series IA_S is calculated as follows:

[0044] The frequency-time series CHNL_S_5 is the frequency-time series F_S of the power supply under test.

[0045] In some embodiments of the present invention, determining the static output parameters of the power supply under test based on the first load change time point sequence, the fifth sequence, and the eleventh sequence includes: Based on the first load change time point sequence, the fifth sequence and the eleventh sequence are divided into multiple segments; Determine the maximum and minimum values ​​in the fifth sequence after segmentation, and the maximum and minimum values ​​in the eleventh sequence after segmentation; Based on the maximum and minimum values ​​in the fifth sequence after segmentation, and the maximum and minimum values ​​in the eleventh sequence after segmentation, the static output parameters of the power supply under test are determined.

[0046] Specifically, first, find the accurate time point sequence TSS (length 12) of load change based on IA_S. Then, divide U_SAV and F_S into 13 segments according to [TSSi+40, TSSi+100] (i=1, 2, ..., 12). For the 4th to 13th segments of U_SAV obtained from the segmentation and selection, find the maximum value Usmxi and the minimum value Usmni (i=1, 2, ..., 10) of each segment, and construct the maximum value sequence Usmx and the minimum value sequence Usmn accordingly. For the Usmx sequence, denote the maximum value as Usmax; for the Usmn sequence, denote the minimum value as Usmin. Similarly, for the sequence F_S, fsmax and fsmin can be found.

[0047] In some embodiments of the present invention, determining the static output parameters of the power supply under test based on the maximum and minimum values ​​in the segmented fifth sequence and the maximum and minimum values ​​in the segmented eleventh sequence includes: Based on the maximum and minimum values ​​in the segmented fifth sequence and the frequency of the power supply under test, the steady-state frequency regulation rate and frequency fluctuation rate of the power supply under test are determined. Based on the maximum and minimum values ​​in the segmented eleventh sequence and the rated output voltage of the power supply under test, the steady-state voltage regulation and voltage fluctuation rate of the power supply under test are determined.

[0048] Specifically, steady-state voltage regulation and Voltage fluctuation rate Steady-state frequency regulation and Frequency volatility The calculation formula is:

[0049]

[0050]

[0051]

[0052] In some embodiments of the present invention, determining the dynamic output parameters of the power supply under test based on the sixth, seventh, eighth, ninth, and tenth sequences includes: The ninth sequence is normalized based on the rated output current of the power supply under test, and the normalized fourth sequence is decomposed by wavelet decomposition. The time points in the wavelet decomposition result where the absolute value of the amplitude of the low-frequency wavelet coefficients is greater than a preset value are determined as the second load change time point sequence. The twelfth sequence is determined based on the sixth sequence, the seventh sequence, the eighth sequence, and the maximum attenuation ratio of the voltage sensor. The twelfth sequence is the time series of the average three-phase line voltage of the power supply under test within the second time period. The dynamic output parameters of the power supply under test are determined based on the second load change time point sequence, the tenth sequence, and the twelfth sequence.

[0053] Specifically, first calculate the average three-phase line voltage time series U_DAV:

[0054] RMS value of load phase A current - time series IA_D:

[0055] The frequency-time series CHNL_D_5 is the frequency-time series F_D of the power supply under test.

[0056] First, find the accurate time sequence TSD (length 6) of load changes based on IA_D. Then, preliminarily divide U_DAV and F_D into 7 segments based on these time points. The method for determining the accurate time of load changes is the same as that for static testing, and will not be repeated here.

[0057] In some embodiments of the present invention, determining the dynamic output parameters of the power supply under test based on the second load change time point sequence, the tenth sequence, and the twelfth sequence includes: The tenth and twelfth sequences are divided into multiple segments based on the second load change time point sequence; The frequency-stable time point sequence is determined in the segmented tenth sequence based on a sliding window of a preset length, and the voltage-stable time point sequence is determined in the segmented twelfth sequence based on a sliding window of a preset length. Multiple frequency stable time periods are determined based on the frequency stable time point sequence and the second load change time point sequence; Multiple voltage stabilization time periods are determined based on the voltage stabilization time point sequence and the second load change time point sequence; The dynamic output parameters of the power supply under test are determined based on the multiple frequency stable time periods, the multiple voltage stable time periods, the tenth sequence, and the twelfth sequence.

[0058] In some embodiments of the present invention, determining the frequency-stable time point sequence in the segmented tenth sequence based on a sliding window of a preset length includes: If the difference between the maximum and minimum values ​​within the sliding window is less than or equal to the difference between the maximum and minimum values ​​within each segment of the tenth sequence after segmentation, the time point corresponding to the starting data point of the sliding window is determined as the frequency stable time point. The sliding window based on a preset length determines the voltage stabilization time point sequence in the segmented twelfth sequence, including: If the difference between the maximum and minimum values ​​within the sliding window is less than or equal to the difference between the maximum and minimum values ​​within each segment of the twelfth sequence after segmentation, the time point corresponding to the starting data point of the sliding window is determined as the voltage stabilization time point.

[0059] Specifically, since the dynamic four-item analysis focuses on the changes in voltage and frequency parameters during the transition after load changes, it is necessary to further determine the voltage and frequency stabilization time points within each data segment. For each data segment, a rectangular window of length n (n≥4) is used for sliding value selection; the maximum value in the rectangular window sequence is denoted as Uwmax, and the minimum value is denoted as Uwmin. When (Uwmax-Uwmin)≤(Usmax-Usmin), the voltage is considered to have reached stability, and the voltage stabilization time point is the time twui corresponding to the starting data point of the rectangular window; similarly, the frequency stabilization time point can be obtained as twfi (i=1, 2, ..., 6). Thus, the voltage stabilization time point sequence TWU and the frequency stabilization time point sequence TWF are constructed respectively.

[0060] In some embodiments of the present invention, the plurality of frequency stabilization time periods, the plurality of voltage stabilization time periods, the tenth sequence, and the twelfth sequence determine the dynamic output parameters of the power supply under test, including: The maximum duration among the plurality of frequency stabilization time periods is determined as the frequency stabilization time, and the maximum duration among the plurality of voltage stabilization time periods is determined as the voltage stabilization time. Based on the maximum and minimum values ​​corresponding to the multiple frequency stable time periods in the tenth sequence, the transient frequency regulation rate of the power supply under test is determined; The transient voltage regulation of the power supply under test is determined based on the maximum and minimum values ​​corresponding to the multiple voltage stability time periods in the twelfth sequence.

[0061] Specifically, the voltage settling time corresponding to each data point is calculated. and frequency settling time :

[0062]

[0063] This forms the voltage stability time series TUS and the frequency stability time TFS. The maximum values ​​of the TUS series (TUSmax) and the TFS series (TFSmax) are then found and can be used as the final voltage stability time and frequency stability time.

[0064] By dividing the [TSDi, TUSi] time series into seven segments corresponding to U_DAV, the maximum value Usmxi and minimum value Usmni (i=1, 2, ..., 7) of each segment can be found. These are used to construct the maximum value sequence Usmx and the minimum value sequence Usmn. For the Usmx sequence, the maximum value is denoted as Usmax; for the Usmn sequence, the minimum value is denoted as Usmin. Similarly, for the F_D sequence, fsmax and fsmin can be found. The transient voltage regulation rate can then be calculated. and Transient frequency regulation and :

[0065]

[0066] The present invention also uses specialized equipment to test and compare the same power supply with the solution provided by the present invention. The comparison results are shown in Table 1: Table 1: Comparison of Test Results

[0067] Although the measurement results of this invention deviate somewhat from those of dedicated equipment, they are still within the acceptable range for engineering applications.

[0068] This invention eliminates the need to purchase dedicated generator set test cabinets or special generator set electrical parameter power testers to complete the corresponding tests, significantly saving R&D budget and reducing R&D costs. Furthermore, the main hardware equipment in the testing scheme, such as the programmable RLC load cabinet, high-voltage differential voltage probe, and benchtop multimeter, are commonly used instruments and testing equipment in actual R&D and production. Therefore, the scheme is easy to implement and makes full use of existing fixed assets.

[0069] The power supply testing system and method provided by the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A power supply testing system, characterized in that, include: A programmable load, connected to the three phases of the power supply under test to form a closed loop; Voltage sensor, used to measure the three-phase voltage signal of the power supply under test; A current sensor is used to measure the A-phase current signal of the power supply under test. A multimeter is used to sample three-phase voltage signals and A-phase current signals to obtain sampled data. The host computer is used to control the programmable load with a first preset logic within a first time period, acquire first sampling data from a multimeter, acquire a first voltage signal from a voltage sensor and determine the voltage signal frequency, determine the static output index of the power supply under test based on the first sampling data and the frequency of the first voltage signal, and control the programmable load with a second preset logic within a second time period, acquire second sampling data from a multimeter, acquire a second voltage signal from a voltage sensor and determine the voltage signal frequency, determine the dynamic output index of the power supply under test based on the second sampling data and the frequency of the second voltage signal. The first preset logic is the increase and decrease of the load, and the second preset logic is the alternating switching between no-load and full-load.

2. The power supply testing system according to claim 1, characterized in that, The programmable load is a three-phase programmable RLC load with YN wiring; The static output parameters of the power supply under test include steady-state voltage regulation, steady-state frequency regulation, voltage fluctuation rate, and frequency fluctuation rate. The dynamic output parameters of the power supply under test include transient voltage regulation, transient frequency regulation, voltage settling time, and frequency settling time.

3. A power supply testing method based on the power supply testing system according to claim 1 or 2, characterized in that, include: Within a first time period, the programmable load is controlled by a first preset logic, and the static output parameters of the power supply under test are determined based on the first sequence, the second sequence, the third sequence, the fourth sequence, and the fifth sequence. Within the second time period, the programmable load is controlled by the second preset logic, and the dynamic output index of the power supply under test is determined based on the sixth, seventh, eighth, ninth and tenth sequences. Wherein, the first sequence is the effective voltage time sequence of phase A of the power supply under test within a first time period, the second sequence is the effective voltage time sequence of phase B of the power supply under test within a first time period, the third sequence is the effective voltage time sequence of phase C of the power supply under test within a first time period, the fourth sequence is the effective current time sequence of phase A of the power supply under test within a first time period, the fifth sequence is the voltage frequency time sequence of phase A of the power supply under test within a first time period, the sixth sequence is the effective voltage time sequence of phase A of the power supply under test within a second time period, the seventh sequence is the effective voltage time sequence of phase B of the power supply under test within a second time period, the eighth sequence is the effective voltage time sequence of phase C of the power supply under test within a second time period, the ninth sequence is the effective current time sequence of phase A of the power supply under test within a second time period, and the tenth sequence is the voltage frequency time sequence of phase A of the power supply under test within a second time period. The first preset logic is the increase and decrease of the load, and the second preset logic is the alternation of no-load and full-load.

4. The power supply testing method according to claim 3, characterized in that, The determination of the static output parameters of the power supply under test based on the first sequence, second sequence, third sequence, fourth sequence, and fifth sequence includes: The fourth sequence is normalized based on the rated output current of the power supply under test, and wavelet decomposition is performed on the normalized fourth sequence. The time points in the wavelet decomposition result where the absolute value of the amplitude of the low-frequency wavelet coefficients is greater than a preset value are determined as the first load change time point sequence. The eleventh sequence is determined based on the first sequence, the second sequence, the third sequence, and the maximum attenuation ratio of the voltage sensor. The eleventh sequence is the time series of the average three-phase line voltage of the power supply under test within the first time period. The static output parameters of the power supply under test are determined based on the first load change time point sequence, the fifth sequence, and the eleventh sequence.

5. The power supply testing method according to claim 4, characterized in that, The determination of the static output parameters of the power supply under test based on the first load change time point sequence, the fifth sequence, and the eleventh sequence includes: Based on the first load change time point sequence, the fifth sequence and the eleventh sequence are divided into multiple segments; Determine the maximum and minimum values ​​in the fifth sequence after segmentation, and the maximum and minimum values ​​in the eleventh sequence after segmentation; Based on the maximum and minimum values ​​in the fifth sequence after segmentation, and the maximum and minimum values ​​in the eleventh sequence after segmentation, the static output parameters of the power supply under test are determined.

6. The power supply testing method according to claim 5, characterized in that, The determination of the static output parameters of the power supply under test based on the maximum and minimum values ​​in the segmented fifth sequence and the maximum and minimum values ​​in the segmented eleventh sequence includes: Based on the maximum and minimum values ​​in the segmented fifth sequence and the frequency of the power supply under test, the steady-state frequency regulation rate and frequency fluctuation rate of the power supply under test are determined. Based on the maximum and minimum values ​​in the segmented eleventh sequence and the rated output voltage of the power supply under test, the steady-state voltage regulation and voltage fluctuation rate of the power supply under test are determined.

7. The power supply testing method according to claim 3, characterized in that, The determination of the dynamic output parameters of the power supply under test based on the sixth, seventh, eighth, ninth, and tenth sequences includes: The ninth sequence is normalized based on the rated output current of the power supply under test, and the normalized fourth sequence is decomposed by wavelet decomposition. The time points in the wavelet decomposition result where the absolute value of the amplitude of the low-frequency wavelet coefficients is greater than a preset value are determined as the second load change time point sequence. The twelfth sequence is determined based on the sixth sequence, the seventh sequence, the eighth sequence, and the maximum attenuation ratio of the voltage sensor. The twelfth sequence is the time series of the average three-phase line voltage of the power supply under test within the second time period. The dynamic output parameters of the power supply under test are determined based on the second load change time point sequence, the tenth sequence, and the twelfth sequence.

8. The power supply testing method according to claim 7, characterized in that, The determination of the dynamic output parameters of the power supply under test based on the second load change time point sequence, the tenth sequence, and the twelfth sequence includes: The tenth and twelfth sequences are divided into multiple segments based on the second load change time point sequence; The frequency-stable time point sequence is determined in the segmented tenth sequence based on a sliding window of a preset length, and the voltage-stable time point sequence is determined in the segmented twelfth sequence based on a sliding window of a preset length. Multiple frequency stable time periods are determined based on the frequency stable time point sequence and the second load change time point sequence; Multiple voltage stabilization time periods are determined based on the voltage stabilization time point sequence and the second load change time point sequence; The dynamic output parameters of the power supply under test are determined based on the multiple frequency stable time periods, the multiple voltage stable time periods, the tenth sequence, and the twelfth sequence.

9. The power supply testing method according to claim 7, characterized in that, The multiple frequency stabilization time periods, the multiple voltage stabilization time periods, the tenth sequence, and the twelfth sequence determine the dynamic output parameters of the power supply under test, including: The maximum duration among the plurality of frequency stabilization time periods is determined as the frequency stabilization time, and the maximum duration among the plurality of voltage stabilization time periods is determined as the voltage stabilization time. Based on the maximum and minimum values ​​corresponding to the multiple frequency stable time periods in the tenth sequence, the transient frequency regulation rate of the power supply under test is determined; The transient voltage regulation of the power supply under test is determined based on the maximum and minimum values ​​corresponding to the multiple voltage stability time periods in the twelfth sequence.

10. The power supply testing method according to claim 8, characterized in that, The process of determining the frequency-stable time point sequence in the segmented tenth sequence using a sliding window of a preset length includes: If the difference between the maximum and minimum values ​​within the sliding window is less than or equal to the difference between the maximum and minimum values ​​within each segment of the tenth sequence after segmentation, the time point corresponding to the starting data point of the sliding window is determined as the frequency stable time point. The sliding window based on a preset length determines the voltage stabilization time point sequence in the segmented twelfth sequence, including: If the difference between the maximum and minimum values ​​within the sliding window is less than or equal to the difference between the maximum and minimum values ​​within each segment of the twelfth sequence after segmentation, the time point corresponding to the starting data point of the sliding window is determined as the voltage stabilization time point.

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