Performance detection method and system for low-voltage alternating-current spare power automatic switching device

Abstract

The invention relates to the technical field of power distribution automation and relay protection, in particular to a performance detection method and system for a low-voltage alternating-current spare power automatic switching device. The method comprises the following steps: in a switching operation process of a main power supply and a standby power supply, acquiring a current change rate of a spare power automatic switching test loop at each moment based on output voltage of the standby power supply in a switching transient state, equivalent inductance and current of the spare power automatic switching test loop at each moment and equivalent impedance of a current limiting branch at each moment; performing constraint control on the current change rate of the spare power automatic switching test loop by adjusting the change rate of the equivalent impedance of the current limiting branch; a current-limiting branch is cut off by a bypass loop under a steady-state condition, a power inductor is introduced into an output end to suppress a high-frequency peak, and meanwhile, multi-layer protection is realized in cooperation with overcurrent and overvoltage clamping; and generating a test result based on the voltage, current and control parameter data at each moment in the switching operation process of the main power supply and the standby power supply. According to the invention, the test precision of the low-voltage alternating-current spare power automatic switching device is effectively improved.

Description

Technical Field

[0001] This invention relates to the fields of power distribution automation and relay protection technology, and in particular to a performance testing method and system for low-voltage AC automatic transfer switch devices. Background Technology

[0002] Low-voltage AC Automatic Transfer Switch (ATS) devices are used to automatically switch to backup power when the main power supply fails, ensuring continuous power supply to critical loads. The switching process is typically completed within tens of milliseconds, involving power status identification, execution of delay criteria, and coordination of disconnection and closing actions. Electrical quantities such as voltage, current, and phase undergo abrupt changes within a very short time. To verify the reliability of the ATS, the test system needs to simulate various operating conditions and simultaneously collect key electrical quantities to achieve a quantitative assessment of its operational performance and stability.

[0003] To accurately evaluate the performance of automatic transfer switch (ATS) devices, the test system must first establish a simulated environment that matches the actual operating scenario, covering different load types and power failure modes. During the simulation, the system collects key electrical quantities such as voltage, current, and power factor in real time before and after the switchover. By comparing and analyzing parameters such as device action time and closing accuracy, it determines whether the device meets design requirements. However, at the moment of power switching, due to the rapid change in electrical quantities, a strong transient impact is generated at the output of the test system, manifested as a rapid current surge forming a peak and a voltage spike. This impact may not only interfere with the normal acquisition of electrical quantities but may also damage components such as amplifiers and sensors inside the test system, thereby affecting the judgment of the stability of the ATS device's operation.

[0004] However, existing solutions for suppressing transient surges during switching have significant shortcomings and struggle to meet diverse needs. Single-stage current limiting schemes rely on current-limiting components with fixed parameters. If an excessively large current-limiting value is chosen to enhance the surge suppression effect, it will overly restrict the normal operating current, resulting in a slower dynamic response of the test system and an inability to keep up with changes in load current. This is especially problematic during the startup of inductive loads, where insufficient current supply may affect test accuracy. Meanwhile, RC absorption networks, while absorbing energy, alter the impedance characteristics of the circuit, causing distortions in the output voltage and current waveforms, leading to overshoot or oscillations. This interferes with the accurate acquisition of electrical quantities, thus affecting the quantitative evaluation of the automatic transfer switch's (ATS) performance. Furthermore, both of these schemes rely heavily on empirical parameter selection. In complex loads or high-power test scenarios, the suppression effect will significantly decrease, resulting in larger test errors for low-voltage AC ATS devices. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the problem that existing methods for suppressing transient impacts during switching rely heavily on empirical parameter adjustment, resulting in large errors in the test results of low-voltage AC standby automatic switching devices.

[0006] To address the aforementioned technical problems, this invention provides a performance testing method for low-voltage AC automatic transfer switch devices, comprising: A current-limiting branch is connected in series to form a backup automatic transfer device for low-voltage AC, thus constituting a backup automatic transfer test circuit. Based on the test scheme of the low-voltage AC automatic transfer device, drive the main power supply and the backup power supply to perform switching operations; During the switching operation between the main power supply and the backup power supply, the current change rate of the backup power supply at each moment is obtained based on the backup power supply output voltage during the switching transient, the equivalent inductance and current of the backup automatic transfer test circuit at each moment, and the equivalent impedance of the current limiting branch at each moment. The rate of change of the current in the standby automatic transfer test circuit at each moment is constrained by adjusting the rate of change of the equivalent impedance of the current-limiting branch. Based on the data at various moments during the switching operation of the main power supply and the backup power supply, the test results of the low-voltage AC automatic transfer switch are generated.

[0007] Preferably, the current change rate of the standby automatic transfer test circuit at each moment is obtained based on the standby power supply output voltage during the switching transient, the equivalent inductance and current of the standby automatic transfer test circuit at each moment, and the equivalent impedance of the current-limiting branch at each moment, using the following formula: , in, for The rate of change of current in the automatic transfer switch test circuit should be monitored at all times. for Always have the current ready for the automatic transfer switch test circuit. For a moment, To provide backup power supply output voltage during switching transients, for The equivalent impedance of the current-limiting branch at any given time. for Always have the equivalent inductance of the automatic transfer switch test circuit ready.

[0008] Preferably, after constraining the rate of change of current in the automatic transfer switch test circuit at each moment, when the voltage and current of the automatic transfer switch test circuit reach their steady-state threshold and the duration is greater than or equal to the set time threshold, the current limiting branch is cut off by bypass. After the current-limiting branch is disconnected, a power inductor is connected in series at the output of the automatic transfer switch test circuit to control the total energy released by the automatic transfer switch test circuit.

[0009] Preferably, a power inductor is connected in series at the output of the automatic transfer switch test circuit. The total energy released by the automatic transfer switch test circuit is controlled by an energy constraint formula, which is: , in, To prepare for the total energy released by the self-starting test circuit, To prepare for the release time of the automatic transfer test circuit, for Always have the current ready for the automatic transfer switch test circuit. For a moment, for The equivalent impedance of the current-limiting branch at any given time. To set an energy safety threshold.

[0010] Preferably, after disconnecting the current-limiting branch, the method further includes: The automatic transfer switch test circuit is equipped with any one or more of the following: overcurrent protection, overvoltage clamping protection, and surge absorption protection.

[0011] Preferably, after the current-limiting branch is cut off, multiple MOSFETs are connected in parallel with the standby automatic transfer test circuit, and a source current-sharing resistor is connected in series with each MOSFET to form multiple parallel branches; Based on the temperature feedback coefficient, the temperature of each parallel branch at each moment, the average temperature of all parallel branches at each moment, and the target current sharing reference current, the instantaneous current of each parallel branch at each moment is obtained. Based on the current feedback coefficient, the target current sharing reference current at the current moment, and the instantaneous current of each parallel branch at the current moment, calculate the current regulation deviation of each parallel branch at the current moment; Based on the temperature feedback coefficient, the average temperature of all parallel branches at the current time, and the temperature of each parallel branch at the current time, the duty cycle deviation of each parallel branch at the current time is obtained. Based on the duty cycle deviation of each parallel branch at the current moment, adjust the duty cycle of the MOSFET of each parallel branch until the deviation between the instantaneous current of each parallel branch and the target current sharing reference current approaches the current regulation deviation of that parallel branch.

[0012] Preferably, the instantaneous current of each parallel branch at each moment is obtained based on the temperature feedback coefficient, the temperature of each parallel branch at each moment, the average temperature of all parallel branches at each moment, and the target current sharing reference current, using the following formula: , in, For the first Instantaneous current of a parallel branch For parallel branch index, for The target current-sharing reference current at any given time. This is the temperature feedback coefficient. The average temperature of all parallel branches, For the first Temperature of each parallel branch.

[0013] Preferably, the current regulation deviation of each parallel branch at the current moment is calculated based on the current feedback coefficient, the target current sharing reference current at the current moment, and the instantaneous current of each parallel branch at the current moment, using the following formula: , in, For the current moment, the first Current regulation deviation of each parallel branch For current feedback coefficient, The target current sharing reference current at the current moment, For the current moment, the first Instantaneous current of a parallel branch.

[0014] Preferably, the duty cycle deviation of each parallel branch at the current time is obtained based on the temperature feedback coefficient, the average temperature of all parallel branches at the current time, and the temperature of each parallel branch at the current time, using the following formula: , in, For the current moment, the first Duty cycle deviation of each parallel branch This is the temperature feedback coefficient. The average temperature of all parallel branches at the current moment. For the current moment, the first Temperature of each parallel branch.

[0015] The present invention also provides a performance testing system for a low-voltage AC automatic transfer switch, comprising: A memory for storing computer programs; a processor for executing the computer programs to implement the steps of the above-described performance testing method for a low-voltage AC automatic transfer switch.

[0016] Compared with the prior art, the above-described technical solution of the present invention has the following advantages: This invention discloses a performance testing method and system for low-voltage AC automatic transfer switch (ATS) devices. The invention combines four key real-time parameters: the voltage output by the backup power supply at the moment of switching, the equivalent inductance of the test circuit at each moment, the actual current of the test circuit at each moment, and the equivalent impedance of the current-limiting branch at each moment. Based on this, by adjusting the rate of change of the equivalent impedance of the current-limiting branch, real-time constraints on the current rise slope are achieved. Through formulaic real-time calculation of matching parameters, it is completely independent of experience and can stably control transient impacts even under complex operating conditions, significantly reducing test errors. Finally, the accurate data from each moment during the switching process is used to generate test results, achieving a precise evaluation of the ATS device's performance.

[0017] Automatic transfer switch (ATS) testing requires simulating various load conditions, including high-power and dynamically changing load scenarios. Stable operation of the power output section is fundamental to ensuring test accuracy. Existing methods typically use multiple MOSFETs or IGBTs in parallel to improve load capacity, but current sharing control is mostly statically designed and does not consider the impact of device thermal drift on conduction characteristics. During long-term operation, local device temperature rise can cause current bias, resulting in unbalanced three-phase output or even overheating protection activation, affecting system reliability. This invention constructs a current-temperature dual-loop feedback model in a multi-MOSFET parallel structure to achieve output current self-balancing and thermally stable operation. First, based on the temperature difference between each parallel branch and the average temperature, combined with a temperature feedback coefficient, the instantaneous current of each branch is dynamically corrected to ensure that current distribution responds in real-time to device thermal drift. When the temperature of a branch exceeds the average level, the instantaneous current of that branch is reduced to decrease heat generation; conversely, the current is appropriately increased to prevent current deviation caused by localized temperature rise at the source. Simultaneously, the deviation between the actual current of each branch and the target reference current is calculated using a current feedback coefficient. This deviation, converted from temperature differences, is then used to adjust the duty cycle of the MOSFET, forming a closed-loop control. Ultimately, this stabilizes the current of each branch near the target reference current, achieving dynamic self-balancing of the output current. This dual-loop feedback mechanism not only eliminates the three-phase output imbalance caused by changes in device conduction characteristics during long-term operation but also prevents localized overheating from triggering protection actions, significantly improving the reliability and stability of the power output section. The current sharing control achieved through current-temperature dual-loop feedback ensures stable output current and three-phase balance of the test system during long-term or high-load testing, avoiding test data distortion caused by power module problems. At the same time, eliminating overheat protection malfunctions ensures the continuity of the test process. Especially when verifying the durability and stability of the automatic transfer switch's switching action, it provides a more reliable load environment, making the test results more accurately reflect the actual performance of the automatic transfer switch. Attached Figure Description

[0018] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein: Figure 1 This is a flowchart of the steps of a performance testing method for a low-voltage AC automatic transfer switch device according to the present invention.

[0019] Figure 2 This is a schematic flowchart of a performance testing method for a low-voltage AC automatic transfer switch according to the present invention.

[0020] Figure 3 This is a schematic diagram of the test plan loading and working condition preset process.

[0021] Figure 4 This is a schematic diagram of the transient shock resistance control sequence.

[0022] Figure 5 This is a schematic diagram of the three-phase measurement and acquisition and key indicator calculation process.

[0023] Figure 6 This is a schematic diagram of the automatic report generation and data archiving process.

[0024] Figure 7 This is a structural diagram of a performance testing system for low-voltage AC automatic transfer switch devices. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0026] Reference Figure 1 , 2 As shown, this embodiment provides a performance testing method for a low-voltage AC automatic transfer switch, including: Step S1: Load the test plan template, enter the rated parameters and operating conditions of the tested low-voltage AC automatic transfer switch (ATS) in the template, and enable the one-click process and report template. like Figure 3 As shown, Figure 3 This is a schematic diagram of the test scheme loading and operating condition pre-setting process. Through the following steps, the system automatically configures the test environment and initializes the operating conditions, providing a unified parameter benchmark for subsequent switching simulations and shock resistance control. Details are as follows: Step S11: Obtain the basic information of the tested low-voltage AC automatic transfer switch, including: rated voltage, rated current, allowable switching time, delay criterion, and load type of the tested low-voltage AC automatic transfer switch; Step S12: Complete wiring verification, grounding check, insulation check and power-on self-test. After the self-test passes, perform zero-point calibration on all electrical quantity acquisition channels of the test system (such as voltage acquisition channel and current acquisition channel) to eliminate channel static error. Then perform multiplier calibration according to the range of the measured parameter to ensure that the range of the acquired data is matched. Perform multi-channel clock synchronization to ensure that the timestamps of subsequent acquired data are consistent and to avoid time deviation affecting the switching time calculation. Step S13: Based on the specific model of the low-voltage AC automatic transfer switch under test, set the key electrical parameters of the main power supply and backup power supply in the test system, including voltage amplitude, operating frequency, phase angle, and phase sequence arrangement; in addition, according to the protection logic and action requirements of the device, set various thresholds to trigger the automatic transfer action, and set the corresponding delay criteria—that is, how long the device delays to perform the switching action after the trigger threshold is met, to ensure that the test conditions are consistent with the actual operating requirements of the device.

[0027] Step S14: Set the sampling rate and anti-aliasing filter, and record the "trigger criterion satisfied time point" as... This is used for subsequent switching time measurements.

[0028] In this embodiment, optionally, the effective voltage value, frequency deviation, and phase sequence status are used as the pre-judgment basis for the power supply condition. When the effective voltage value of the main power supply is lower than the set undervoltage threshold, or the frequency deviation exceeds the set range, or the phase sequence detection is incorrect, and these triggering conditions are met for a duration that reaches the delay criterion set in step S13, the system automatically sets the switching flag (marking the start of the automatic transfer switch) and locks the time point at this time as the reference time point. This reference time point will be used to calculate the switching time of the automatic transfer switch device in the future. This refers to the time interval from the locked reference time point to the successful commissioning of the backup power supply and the restoration of normal power supply to the load.

[0029] In this embodiment, optionally, a sliding window is used to pre-judge the effective voltage value, frequency deviation, and phase sequence. This includes: continuously analyzing the effective voltage value data, frequency deviation data, and phase sequence detection results collected within a fixed-duration sliding window. For example, when the effective voltage value is continuously detected to be close to the undervoltage threshold, the frequency deviation gradually approaches the set range, or the phase sequence shows intermittent abnormalities within the window, the system will identify these potential operating conditions that may trigger switching actions in advance and mark them as "pending switching status".

[0030] This dynamic monitoring method can avoid misjudgments caused by instantaneous interference (such as voltage spikes or short-term frequency fluctuations), while also identifying scenarios where switching might actually occur in advance. This ensures that test resources are concentrated on effective operating conditions, reduces repeated testing caused by invalid triggers or misjudgments, and improves overall test efficiency.

[0031] This invention automatically loads key parameters and trigger criteria of the tested low-voltage AC automatic transfer switch by using templated parameter configuration and pre-judgment of operating conditions, avoiding repeated settings and invalid tests, reducing manual intervention and computational overhead, and improving test efficiency and consistency.

[0032] Step S2: Based on the test scheme of the low-voltage AC automatic transfer switch, drive the main power supply and the backup power supply to perform switching operations, that is, simulate the whole process of the backup power supply being put into operation when the main power supply is abnormal, or switching back to the main power supply after the main power supply is restored.

[0033] During this process, the testing system synchronously collects real-time waveform data of three-phase voltage and three-phase current, and records key electrical parameters such as the phase relationship of each phase and power supply frequency. Events such as "triggering, disconnection, parallel connection, closing, and protection action" during the switching process are marked and timestamped. Finally, the time information of all events is integrated to form a continuous event timeline, clearly presenting the timing logic of the switching process.

[0034] In this embodiment, the switching simulation optionally supports two operating modes: the single-run mode is suitable for independent testing under specific working conditions and automatically stops after executing a complete switching process once; the loop mode can repeatedly execute the switching operation a set number of times to verify the stability of the device after multiple operations.

[0035] During scenario execution, continuous time-series data of three-phase voltage and current are acquired through synchronous sampling to ensure the temporal correlation of waveforms. All events (such as trigger signal generation, closing command issuance, and protection action response) are assigned precise timestamps and tagged for easy traceability. In addition, the system solution library also includes various abnormal operating conditions, such as single-phase or two-phase power loss, sudden load increase or unload, etc. These scenarios can be added to the test schemes individually to simulate more complex real-world operational faults.

[0036] Compared to the traditional method of recording waveforms by single-point sampling, this invention adopts multi-channel synchronous sampling and introduces an event time axis management mechanism, so that subsequent waveform analysis and control actions have a unified time reference, providing a data foundation for dynamic shock resistance control and subsequent parameter determination.

[0037] Step S3: Implement transient surge protection control: series current limiting → steady-state bypass → output power inductor smoothing, and combined with multi-layer protection such as overcurrent / overvoltage clamping; like Figure 4 As shown, Figure 4 This is a schematic diagram of the transient surge protection control sequence. In traditional automatic switching tests, surge protection control typically employs only a single-stage current limiting structure, resulting in lag and limited control accuracy. To address issues such as uncontrollable transient current and severe waveform distortion, this invention proposes a multi-stage collaborative surge protection control theory. Through staged current limiting and waveform smoothing, real-time controllability of the switching process is achieved. The power output stage operates according to the sequence control of "current limiting → bypass → smoothing," with multiple layers of protection superimposed.

[0038] Traffic limiting phase: A current-limiting branch is connected in series with the low-voltage AC automatic transfer switch to form an automatic transfer switch test circuit; this limits the current rise rate and suppresses... ; To achieve dynamic control of transient current during switching, this invention establishes a current change model: During the switching operation between the main power supply and the backup power supply, based on the backup power supply output voltage during the switching transient, the equivalent inductance and current of the backup automatic transfer test circuit at each moment, and the equivalent impedance of the current-limiting branch at each moment, the current change rate of the backup automatic transfer test circuit at each moment is obtained, as shown in the formula: , in, for The rate of change of current in the automatic transfer switch test circuit should be monitored at all times. for Always have the current ready for the automatic transfer switch test circuit. For a moment, To provide backup power supply output voltage during switching transients, for The equivalent impedance of the current-limiting branch at any given time. for Always have the equivalent inductance of the automatic transfer switch test circuit ready.

[0039] By adjusting the rate of change of the equivalent impedance of the current-limiting branch, the rate of change of the current in the automatic transfer switch test circuit at each moment is constrained, thereby achieving response constraints during the current-limiting phase. This ensures that the absolute value of the rate of change of the current in the automatic transfer switch test circuit is less than or equal to the current rise slope threshold, i.e., satisfying the following: ,in, The threshold for the current rise slope; In this embodiment, specifically, the current limiting branch is either an NTC or a controllable electronic current limiting circuit.

[0040] Bypass phase: After constraining the rate of change of current in the automatic transfer switch test circuit at each moment, when the voltage and current of the automatic transfer switch test circuit reach their steady-state threshold and the duration is greater than or equal to the set time threshold, the current limiting branch is cut off by bypass to reduce losses and improve efficiency. Smoothing and Protection Phase: After the current-limiting branch is disconnected, a power inductor is connected in series at the output of the automatic transfer switch test circuit to smooth the current waveform. The total energy released by the automatic transfer switch test circuit is controlled by the energy constraint formula.

[0041] In this embodiment, preferably, the energy constraint formula is: , in, To prepare for the total energy released by the self-starting test circuit, To prepare for the release time of the automatic transfer test circuit, for Always have the current ready for the automatic transfer switch test circuit. For a moment, for The equivalent impedance of the current-limiting branch at any given time. To set an energy safety threshold.

[0042] This invention transforms current waveform control from "empirical current limiting" to "parameterized and calculable process", ensuring that switching impacts are predictable and waveforms are smooth and controllable.

[0043] In this embodiment, preferably, after the current-limiting branch is disconnected, the method further includes: The automatic transfer switch test circuit is equipped with any one or more of the following: overcurrent protection, overvoltage clamping protection, and surge absorption protection.

[0044] In this embodiment, the power stage employs multiple MOS transistors connected in parallel and configured with source current-sharing resistors to alleviate current bias caused by device discreteness. Depending on the power level, a two-phase or multi-phase parallel topology can be adopted to improve power density and dynamic response. The thermal management section adopts a high thermal conductivity heat sink, heat pipes, and air-cooled partition design, and is equipped with over-temperature protection and closed-loop fan speed control.

[0045] To address the issues of uneven temperature rise and branch current imbalance that traditional testers tend to experience under high power and long-term operation, this invention proposes an electro-thermal coupled dynamic current sharing control model. Through the coordinated adjustment of temperature feedback and current feedback, thermal balance and current sharing among branches are achieved.

[0046] In this embodiment, preferably, after the current limiting branch is cut off, multiple MOS transistors are connected in parallel with the standby automatic transfer test circuit, and a source current sharing resistor is connected in series with each MOS transistor to form multiple parallel branches; After the current-limiting branch is disconnected, based on the temperature feedback coefficient, the temperature of each parallel branch at each moment, the average temperature of all parallel branches at each moment, and the target current-sharing reference current, the instantaneous current of each parallel branch at each moment is obtained through the electro-thermal coupling dynamic current-sharing control formula; the formula is: , in, For the first Instantaneous current of a parallel branch For parallel branch index, for The target current-sharing reference current at any given time. This is the temperature feedback coefficient. The average temperature of all parallel branches, For the first Temperature of each parallel branch.

[0047] Based on the current feedback coefficient, the target current sharing reference current at the current moment, and the instantaneous current of each parallel branch at the current moment, the current regulation deviation of each parallel branch at the current moment is calculated using the following formula: , in, For the first Instantaneous current of a parallel branch For parallel branch index, for The target current-sharing reference current at any given time. This is the temperature feedback coefficient. The average temperature of all parallel branches, For the first Temperature of each parallel branch.

[0048] Based on the temperature feedback coefficient, the average temperature of all parallel branches at the current moment, and the temperature of each parallel branch at the current moment, the duty cycle deviation of each parallel branch at the current moment is obtained using the following formula: , in, For the current moment, the first Duty cycle deviation of each parallel branch This is the temperature feedback coefficient. The average temperature of all parallel branches at the current moment. For the current moment, the first Temperature of each parallel branch.

[0049] Based on the duty cycle deviation of each parallel branch at the current moment, adjust the duty cycle of the MOSFET in each parallel branch until the deviation between the instantaneous current of each parallel branch and the target current sharing reference current approaches the current regulation deviation of that parallel branch.

[0050] When the temperature of a certain branch is higher than the average value, that is ≥ At that time, the duty cycle of the parallel branch MOSFET is reduced to decrease the current. The duty cycle decreases, and conversely, it increases to compensate for the increase, ultimately forming a dual closed-loop regulation. This mechanism can correct the deviation of each branch in real time, keeping ΔI% within 2%, effectively preventing local overheating and current concentration, and ensuring long-term operational stability.

[0051] The power output stage can adopt a structure of multiple MOS connected in parallel and equipped with source current sharing resistors, combined with current sampling feedback to achieve multi-phase parallel and dynamic current sharing control; the bypass element can be a relay or a solid-state device; the clamping / suppression network can adopt a combination of TVS, varistor and RC absorption; the thermal management adopts a partitioned design of high thermal conductivity heat sink / heat pipe / air cooling and is equipped with over-temperature protection.

[0052] This invention employs a collaborative surge protection link of "current limiting → bypass → power inductor smoothing + overcurrent / overvoltage clamping" to significantly suppress surges. With peak impact This ensures that the waveform at the moment of switching is authentic and reproducible, improving the stability and measurement accuracy of the device under test. In addition, the power stage of this invention adopts multiple MOS parallel connection + current sharing and selectable multi-phase parallel operation, combined with refined thermal management and over-temperature protection, to provide high power, long-term stable output, controllable three-phase current deviation, adaptable to heavy load and complex operating conditions, and reduce the risk of derating and shutdown.

[0053] Step S4: Determine and record key indicators: switching behavior and time parameters, peak impact current. Three-phase current sharing deviation And output accuracy / temperature rise, etc.; like Figure 5 As shown, Figure 5 This is a schematic diagram of the three-phase measurement and acquisition and key indicator calculation process.

[0054] Step S41: Set the time point when the main power supply fault criteria are met. The time point when the backup power supply is stably closed is met. The difference is used as the switching time. The formula is: When necessary, a "parallel protection criterion" should be introduced to avoid grid connection conflicts.

[0055] Step S42: Search for the current peak value within the switching transient time window as the impact peak current, and record the peak amplitude and duration. The window length can be set. If the peak value is clamped by the protection, the protection channel is recorded simultaneously. Step S43: Calculate the three-phase average current within the steady-state window and give the percentage deviation, i.e., the three-phase current sharing deviation. Calculate the three-phase average current within the steady-state window. , , , Simultaneously, the output accuracy and temperature rise of key components are statistically analyzed to evaluate steady-state performance and thermal stability. This is the current value of phase A. This is the B-phase current value. This represents the C-phase current value. Step S44: Determine the level and list the events: , , The system compares output accuracy and temperature rise with thresholds to output qualified / boundary / unqualified ratings and an event list (including timeline and waveform screenshots).

[0056] The acquired waveforms are first preprocessed by removing DC, normalizing amplitude, aligning phase, and filtering against power frequency / high frequency interference. If necessary, oversampling and window functions are used to improve the accuracy of peak capture and time measurement.

[0057] This invention establishes an evaluation system based on synchronous data acquisition and quantitative criteria, which can automatically calculate the switching time. Impact peak Three-phase current sharing deviation The output accuracy and temperature rise indicators enhance the distinguishability and reliability of the results, facilitating consistent rating and traceability between type testing and on-site acceptance.

[0058] like Figure 6 As shown, Figure 6 This is a schematic diagram of the automatic report generation and data archiving process.

[0059] Step S5: Based on the data at each moment during the switching operation of the main power supply and the backup power supply, generate the test results of the low-voltage AC automatic transfer switch, automatically generate a standardized test report, archive the original data and configuration, and support the reuse of the solution library and export in multiple formats.

[0060] In this embodiment, optionally, the report generation supports templated output, including: test configuration, event timeline, typical waveform screenshots, key indicator table and grading results; supports export in multiple formats such as PDF / Word / CSV, and archives the original data (such as CSV / binary waveform) and solution configuration to the database / solution library for retesting and traceability.

[0061] This invention integrates one-click execution, process monitoring / alarm, and automatic reporting, enabling standardized archiving and reuse of data and configurations, significantly reducing manual processing and training costs. The system features modular design and standardized interfaces, making it convenient for on-site deployment and highly applicable, with good engineering promotion value and economic benefits.

[0062] This invention establishes a multi-stage collaborative shock resistance control theory of "current limiting—bypass—smoothing—protection", through real-time monitoring. By dynamically adjusting current limiting and bypass strategies based on voltage drop amplitude ΔV, this invention achieves predictable and controllable transient impacts. It also introduces an electro-thermal coupling dynamic current sharing method, constructing a current-temperature dual-loop feedback model in a multi-MOS parallel structure to achieve output current self-balancing and thermally stable operation. This breakthrough overcomes the static control and manual judgment modes of traditional test instruments, providing higher accuracy, stability, and intelligent support for the performance verification of low-voltage AC automatic transfer switch devices.

[0063] When robustness needs to be evaluated, this invention can enable abnormal operating condition injection: single-phase / two-phase power failure, phase sequence error, asymmetrical load, sudden load increase / decrease, etc.; and set the test mode to cyclic to evaluate under repeated switching and thermal steady state. , , Trends and temperature rise evolution. All indicators and events from each cycle are automatically aggregated and included in the final report. Unlike conventional testing, which only performs a single verification, this solution supports multiple rounds of cyclic testing, enabling quantitative assessment of long-term trends in indicators such as shock resistance and flow uniformity stability.

[0064] refer to Figure 7 This second embodiment provides a performance testing device for a low-voltage AC automatic transfer switch, comprising: The power output and surge protection control module is used to obtain the current change rate of the backup automatic transfer test circuit at each moment during the switching operation between the main power supply and the backup power supply, based on the backup power supply output voltage during the switching transient, the equivalent inductance and current of the backup automatic transfer test circuit at each moment, and the equivalent impedance of the current limiting branch at each moment. The rate of change of the current in the standby automatic transfer test circuit at each moment is constrained by adjusting the rate of change of the equivalent impedance of the current-limiting branch. After constraining the rate of change of current in the automatic transfer switch test circuit at each moment, when the voltage and current of the automatic transfer switch test circuit reach their steady-state threshold and the duration is greater than or equal to the set time threshold, the current limiting branch is cut off by bypass. After the current-limiting branch is disconnected, a power inductor is connected in series at the output of the automatic transfer switch test circuit, and the total energy released by the automatic transfer switch test circuit is controlled by the energy constraint formula. Based on the temperature feedback coefficient, the temperature of each parallel branch at each moment, the average temperature of all parallel branches at each moment, and the target current sharing reference current, the instantaneous current of each parallel branch at each moment is obtained. Based on the current feedback coefficient, the target current sharing reference current at the current moment, and the instantaneous current of each parallel branch at the current moment, calculate the current regulation deviation of each parallel branch at the current moment; Based on the temperature feedback coefficient, the average temperature of all parallel branches at the current time, and the temperature of each parallel branch at the current time, the duty cycle deviation of each parallel branch at the current time is obtained. Based on the duty cycle deviation of each parallel branch at the current moment, adjust the duty cycle of the MOSFET of each parallel branch until the deviation between the instantaneous current of each parallel branch and the target current sharing reference current approaches the current regulation deviation of that parallel branch. The automatic transfer switch test circuit is equipped with overcurrent protection, overvoltage clamping protection, and surge absorption protection. The measurement and acquisition module is used to collect data at various moments during the switching operation between the main power supply and the backup power supply. The control and human-machine interaction module provides a visual interface, supports a solution template library, one-click start, process monitoring / alarm, automatic report generation and data management; supports permission and log management to ensure the traceability of configuration and testing processes; and provides a secondary development interface (API) for integration with third-party management systems or laboratory information platforms. The data processing and reporting module is used to generate a test report for the low-voltage AC automatic transfer switch based on data at various moments during the switching operation between the main power supply and the backup power supply. The thermal management and safety protection module is equipped with a thermal management system featuring a high thermal conductivity radiator, heat pipes, and air-cooled partition design to ensure safe operation over long periods.

[0065] This third embodiment provides a performance testing system for a low-voltage AC automatic transfer switch, including: A memory for storing computer programs; a processor for executing the computer programs to implement the steps of the above-described performance testing method for a low-voltage AC automatic transfer switch.

[0066] The above implementation method constructs an overall closed loop around "reproducible scenarios, controllable transients, quantifiable indicators, and traceable reports": it suppresses transient impacts during switching through coordinated control of "current limiting → bypassing → smoothing + protection," and obtains data through synchronous data acquisition and standardized calculations. , , Key indicators are defined and standardized reports are generated in a templated and one-click manner, making them suitable for batch applications in laboratory type testing and field verification.

[0067] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0068] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0069] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0070] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0071] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A performance detection method for a low-voltage alternating current spare power automatic switching device, characterized in that, The method comprises the following steps: including: including a series current limiting branch for the low-voltage AC backup power automatic switching device to form a backup power automatic switching device test loop; based on the test scheme of the low-voltage AC backup power automatic switching device, driving the main power supply and the standby power supply to perform switching operation; during the switching operation of the main power supply and the standby power supply, based on the output voltage of the standby power supply at the switching transient, the equivalent inductance and current of the backup power automatic switching device test loop at each moment, and the equivalent impedance of the current limiting branch at each moment, the current change rate of the backup power automatic switching device test loop at each moment is obtained; by adjusting the change rate of the equivalent impedance of the current limiting branch, the current change rate of the backup power automatic switching device test loop at each moment is constrained; 2. The performance detection method for the low-voltage alternating current backup automatic switching device according to claim 1, characterized in that, based on the data at each moment during the switching operation of the main power supply and the standby power supply, the test result of the low-voltage AC backup power automatic switching device is generated. ， wherein, is the current rate of change of the test circuit of the backup power supply, is the current of the test circuit of the backup power supply, is the time, is the output voltage of the backup power supply during switching transient, is the equivalent impedance of the current limiting branch at the time, is the equivalent inductance of the test circuit of the backup power supply at the time.

3. The performance detection method for the low-voltage alternating current backup automatic switching device according to claim 1, characterized in that, The formula for obtaining the current change rate of the backup power automatic switching device test loop at each moment based on the output voltage of the standby power supply at the switching transient, the equivalent inductance and current of the backup power automatic switching device test loop at each moment, and the equivalent impedance of the current limiting branch at each moment is: After constraining the current change rate of the backup power automatic switching device test loop at each moment, when the voltage and current of the backup power automatic switching device test loop reach its steady-state threshold and the duration is greater than or equal to the set time threshold, the current limiting branch is removed through the bypass; 4. The performance detection method for the low-voltage alternating current backup automatic switching device according to claim 3, characterized in that, After removing the current limiting branch, a power inductor is connected in series at the output end of the backup power automatic switching device test loop to control the total energy released by the backup power automatic switching device test loop. ， wherein, total energy released by the backup power automatic throw-in test circuit, release time of the backup power automatic throw-in test circuit, is current of the backup power automatic throw-in test circuit at the moment, is the moment, is equivalent impedance of the current-limiting branch at the moment, is the set energy safety threshold.

5. The performance detection method for the low-voltage alternating current backup automatic switching device according to claim 3, characterized in that, After removing the current limiting branch, a power inductor is connected in series at the output end of the backup power automatic switching device test loop to control the total energy released by the backup power automatic switching device test loop. After removing the current limiting branch, it also includes:

6. The performance detection method for the low-voltage alternating current backup automatic switching device according to claim 3, characterized in that, setting any one or more of overcurrent protection, overvoltage clamping protection, and surge absorption protection for the backup power automatic switching device test loop. After removing the current limiting branch, a plurality of MOS transistors are connected in parallel with the backup power automatic switching device test loop, and a source current sharing resistor is connected in series with each MOS transistor to form a plurality of parallel branches; based on the temperature feedback coefficient, the temperature of each parallel branch at each moment, the average temperature of all parallel branches at each moment, and the target current sharing reference current, the instantaneous current of each parallel branch at each moment is obtained; based on the current feedback coefficient, the target current sharing reference current at the current moment, and the instantaneous current of each parallel branch at the current moment, the current adjustment deviation of each parallel branch at the current moment is calculated; based on the temperature feedback coefficient, the average temperature of all parallel branches at the current moment, and the temperature of each parallel branch at the current moment, the duty cycle deviation of each parallel branch at the current moment is obtained; 7. The performance detection method for the low-voltage alternating current backup automatic switching device according to claim 6, characterized in that, based on the duty cycle deviation of each parallel branch at the current moment, the duty cycle of each parallel branch MOS transistor is adjusted until the deviation between the instantaneous current of each parallel branch at the current moment and the target current sharing reference current approaches the current adjustment deviation of the parallel branch. ， wherein, is the instantaneous current of the th parallel branch, is the parallel branch index, is the target current sharing reference current at the moment, is the temperature feedback coefficient, is the average temperature of all parallel branches, is the temperature of the th parallel branch.

8. The performance detection method for the low-voltage alternating current backup automatic switching device according to claim 6, characterized in that, The formula for obtaining the instantaneous current of each parallel branch at each moment based on the temperature feedback coefficient, the temperature of each parallel branch at each moment, the average temperature of all parallel branches at each moment, and the target current sharing reference current is: The formula for calculating the current adjustment deviation of each parallel branch at the current moment based on the current feedback coefficient, the target current sharing reference current at the current moment, and the instantaneous current of each parallel branch at the current moment is: ， in, For the current moment Current regulation deviation of each parallel branch For current feedback coefficient, The target current sharing reference current at the current moment, For the current moment Instantaneous current of a parallel branch.

9. The performance detection method for the low-voltage alternating current backup automatic switching device according to claim 6, characterized in that, The duty cycle deviation of each parallel branch at the current moment is obtained based on the temperature feedback coefficient, the average temperature of all parallel branches at the current moment, and the temperature of each parallel branch at the current moment, and the formula is: ， in, For the current moment Duty cycle deviation of each parallel branch This is the temperature feedback coefficient. The average temperature of all parallel branches at the current moment. For the current moment Temperature of each parallel branch.

10. A performance detection system for a low-voltage alternating current spare power device, characterized in that, The method comprises the following steps: The memory is used for storing a computer program. The processor is used for executing the computer program to realize the steps of the performance detection method for the low-voltage alternating current backup automatic switching device in any one of claims 1 to 9.

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