Switching power supply automatic test system

Abstract

The invention discloses an automatic test system for a switching power supply, which relates to the technical field of switching power supply testing and comprises a test control module, an input power supply module, a load simulation module, a power supply monitoring module, a fault detection module and a data storage module, the test control module comprises a user interaction interface, a tester sets test items and test conditions through the user interaction interface, and multiple modules such as a load simulation module, a fault detection module, a power supply efficiency stability detection unit, a temperature efficiency detection unit and a ripple energy detection unit work cooperatively. The performance of the switching power supply under different load, temperature and noise conditions is comprehensively tested, comprehensive evaluation is carried out, the stability and efficiency of the power supply are accurately evaluated, the accuracy of a test result is ensured, automatic control is realized through the test control module, and the test efficiency and precision are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply testing, and specifically provides an automatic testing system for switching power supplies. Background Art

[0002] A switching power supply is a high-frequency switching energy conversion electronic circuit, often used as a power supply for equipment. In the field of electronic design, switching power supplies have become the most important power supply design method in the field of electronic product design due to their many advantages such as small volume, light weight, low power consumption, high efficiency, fast conversion speed, wide voltage regulation range, good filtering efficiency, and small number of required filter capacitors. The quality of the switching power supply design is directly related to the success or failure of the product design, as well as the design stability and product quality of electronic products. Therefore, the testing of switching power supplies has become an important part of product design.

[0003] At present, the testing methods for switching power supplies generally involve manually adjusting instruments such as load meters, function generators, oscilloscopes, and frequency response analyzers, which have problems such as low testing efficiency and inconsistent testing standards. Traditional switching power supply detection usually only focuses on basic electrical parameters such as output voltage and current, and cannot comprehensively evaluate the overall performance of the power supply, which easily leads to unstable phenomena in the actual application of the power supply. Moreover, current switching power supply detection usually only focuses on the performance under each fixed load, lacking a unified analysis of the full load range, thus reducing the accuracy of switching power supply testing. Summary of the Invention

[0004] The purpose of the present invention is to provide an automatic testing system for switching power supplies, which solves the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: An automatic testing system for switching power supplies, including a test control module, an input power supply module, a load simulation module, a power supply monitoring module, a fault detection module, and a data storage module;

[0006] The test control module is used to control the start and stop of other modules through an embedded controller. The test control module includes a user interface, and testers set test items and test conditions through the user interface;

[0007] The load simulation module is used to control the output load of the switching power supply to test the performance of the switching power supply under different load conditions;

[0008] The power supply monitoring module is used to monitor various parameters in real time during the power supply testing process and display them through the user interface;

[0009] The fault detection module includes a power efficiency stability detection unit, a temperature efficiency detection unit, a ripple energy detection unit, and a comprehensive evaluation unit;

[0010] The power efficiency stability detection unit is used to quantify the stability of the switching power supply efficiency during the load change process. The temperature performance detection unit evaluates the influence of temperature change on the power supply stability by detecting the voltage and power data of the switching power supply at different temperatures. The ripple energy detection unit is used to detect the ripple voltage generated by the power supply in the high-frequency range and evaluate the interference of high-frequency noise on the power supply stability and the surrounding circuits. The comprehensive evaluation unit comprehensively evaluates the switching power supply by combining the detection results of the power efficiency stability detection unit, the temperature performance detection unit, and the ripple energy detection unit to determine the overall quality of the switching power supply.

[0011] Optionally, the detection process of the power efficiency stability detection unit is as follows:

[0012]

[0013] Where E is the efficiency stability score;

[0014] X avg is the average efficiency;

[0015] X max is the maximum efficiency, and X min is the minimum efficiency;

[0016] σ x is the efficiency standard deviation;

[0017] P out，i is the output power of the power supply at load point i;

[0018] P in is the input power of the power supply at load point i;

[0019] N is the number of load points;

[0020] The efficiency stability score E is used to quantify the stability of the switching power supply efficiency during the load change process. The larger the efficiency stability score E, the higher the efficiency and the smaller the fluctuation of the power supply during the load change, and the better the stability. The smaller the efficiency stability score E, the lower the efficiency and the larger the fluctuation of the power supply during the load change, and the worse the stability. Set the efficiency stability threshold of the efficiency stability score E as Y1. When the efficiency stability score E is greater than the efficiency stability threshold Y1, the power supply is qualified, indicating small efficiency fluctuation and high stability. When the efficiency stability score E is less than the efficiency stability threshold Y1, the power supply is unqualified.

[0021] Optionally, the detection process of the temperature performance detection unit is as follows:

[0022]

[0023] Where TD is the temperature performance stability score;

[0024] ΔV out It is the output voltage offset, representing the absolute change in the output voltage of the switching power supply relative to the nominal value during the temperature change process;

[0025] ΔT is the temperature change amount, representing the temperature change range set in the test;

[0026] V out,hot is the high - temperature output voltage;

[0027] V out,cold is the low - temperature output voltage;

[0028] V nom is the nominal voltage;

[0029] X hot is the high - temperature efficiency, X cold is the low - temperature efficiency;

[0030] P loss,hot is the high - temperature power loss;

[0031] P loss,cold is the low - temperature power loss;

[0032] β is the power - loss influence coefficient, with an initial value of 1;

[0033] is the logarithmic term, used to quantify the relative increase in power loss at high temperatures;

[0034] The high - temperature power loss P loss,hot and the low - temperature power loss P loss,cold are obtained as follows:

[0035] P loss,hot = P in,hot - P out,hot

[0036] P loss,cold = P in,coldt - P out,cold

[0037] where P in,hot is the high - temperature input power, P out,hot is the high - temperature output power;

[0038] P in,cold is the low - temperature input power, P out,cold is the low - temperature output power;

[0039] The temperature efficiency stability score TD represents the degree of influence of temperature change on power supply stability. The larger the temperature efficiency stability score TD, the greater the influence of temperature change on voltage stability. The smaller the temperature efficiency stability score TD, the greater the influence on efficiency. The efficiency threshold of the temperature efficiency stability score TD is set as Y2. When the temperature efficiency stability score TD ≤ the efficiency threshold Y2, the power supply is qualified, indicating that the influence of temperature increase on performance can be ignored. When the temperature efficiency stability score TD > the efficiency threshold Y2, the power supply is unqualified, indicating that the temperature increase causes a sharp drop in efficiency and excessive voltage offset.

[0040] Optionally, the ripple energy detection unit detects as follows:

[0041]

[0042] where R is the power supply noise hazard index;

[0043] V ripple (f) is the measured ripple voltage amplitude at frequency f;

[0044] W(f) is the weight of frequency f;

[0045] MHz is megahertz, representing the unit symbol;

[0046] Taking the summation range from 1 megahertz to 10 megahertz can cover the typical switching frequencies of the switching power supply, avoid radio frequency interference, and enable the ripple energy detection unit to focus on the noise generated by the switching behavior of the switching power supply itself rather than external environmental interference. The noise hazard threshold one of the power supply noise hazard index R is set as Y31, and the noise hazard threshold two is Y32. When the power supply noise hazard index R ≤ the noise hazard threshold one Y31, the power supply is qualified, indicating that the high-frequency noise energy is low. When the temperature efficiency stability score TD ≥ the efficiency threshold two Y32, the power supply is unqualified, indicating that the high-frequency noise interferes with the adjacent circuit. When Y31 ≤ R < Y32, it means that the high-frequency noise energy is in a critical state. At this time, the power loss coefficient β is adjusted as follows:

[0047]

[0048] where Nβ is the new power loss coefficient;

[0049] Since the noise will interfere with the signal acquisition of the temperature sensor, resulting in distorted temperature control feedback, by using the new power loss coefficient Nβ to replace the initial power loss coefficient β when Y31 ≤ R < Y32, that is, dynamically adjusting the power loss coefficient β to compensate for the error caused by high-frequency noise, improving the accuracy of the temperature efficiency stability score TD, and reducing the fluctuation influence of the noise on the power supply.

[0050] Optionally, the comprehensive evaluation unit evaluates as follows:

[0051]

[0052] Among them, ZS is the comprehensive power supply score;

[0053] E is the efficiency stability score;

[0054] Y1 is the efficiency stability threshold;

[0055] W1 is the influence coefficient of the efficiency stability score;

[0056] TD is the temperature efficiency stability score;

[0057] Y2 is the efficiency threshold;

[0058] W2 is the influence coefficient of the temperature efficiency stability score;

[0059] R is the power supply noise hazard index;

[0060] W3 is the influence coefficient of the power supply noise hazard index;

[0061] W1 + W2 + W3 = 1;

[0062] Set the first comprehensive threshold of the power supply comprehensive score ZS as Z1, and the second comprehensive threshold as Z2. When the power supply comprehensive score ZS ≥ the first comprehensive threshold Z1, it means the power supply is qualified. When the power supply comprehensive score ZS < the second comprehensive threshold Z2, it means the power supply is unqualified. When the second comprehensive threshold Z2 ≤ the power supply comprehensive score ZS < the first comprehensive threshold Z1, it means the power supply is in a sub-healthy state and needs to be re-inspected.

[0063] Optionally, the input power supply module is used to provide the input power required for switching power supply testing, and the input power supply module includes a power filter and a noise suppressor.

[0064] Optionally, the system alarm module is used to display different alarm lights through the user interaction interface according to the detection results of the switching power supply, so as to facilitate the tester to quickly understand the test results.

[0065] Optionally, the data storage module is used to store the switching power supply test process and test result data. The data storage module includes an on-body storage unit and a cloud storage unit, and the on-body storage unit includes a mechanical hard disk.

[0066] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0067] 1. The present invention controls the output load of a switching power supply through a load simulation module to test the performance of the switching power supply under different load conditions. The power efficiency stability detection unit in the fault detection module tests the stability of the efficiency of the switching power supply during the load change process. The power efficiency stability detection unit divides the load range into multiple load points and conducts a unified analysis by combining all load points, fully considering the power efficiency stability under different loads. Then, the temperature effect detection unit quantifies the impact of temperature changes on the power supply. By analyzing the efficiency, power loss data, and voltage data at high and low temperatures, the impact of temperature changes on the power supply is evaluated, making the test of the switching power supply more in line with the actual situation and improving the accuracy of the switching power supply test.

[0068] 2. The present invention can evaluate the noise characteristics of a switching power supply, especially the noise in the high-frequency range, by detecting the ripple voltage in different frequency ranges through the ripple energy detection unit, thereby performing an accurate noise assessment on the power supply. Finally, the comprehensive evaluation unit combines the detection results of the power efficiency stability detection unit, the temperature effect detection unit, and the ripple energy detection unit to comprehensively evaluate the switching power supply to determine the overall quality of the switching power supply, comprehensively evaluate the overall performance of the power supply, avoid the limitations of relying on a single test result, and further improve the accuracy of the switching power supply test.

[0069] 3. The present invention controls the startup and stop of other modules through an embedded controller, sets test items and test conditions through a user interface to achieve remote control, and real-time monitors various parameters during the power supply test process through a power monitoring module and displays them on the user interface, eliminating the need to manually operate each instrument, improving the automation level of the switching power supply detection, saving the time for manual setting, and improving the test efficiency and accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Figure 1 is the system module block diagram of the present invention;

[0071] Figure 2 is the fault detection module block diagram of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0072] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0073] Embodiment 1:

[0074] Please refer to Figure 1 and Figure 2, this embodiment provides an automatic test system for a switching power supply, including a test control module, an input power supply module, a load simulation module, a power supply monitoring module, a fault detection module, and a data storage module;

[0075] The test control module is used to control the start and stop of other modules through an embedded controller. The test control module includes a user interface, and testers set test items and test conditions through the user interface;

[0076] The input power supply module is used to provide the input power required for switching power supply testing. The input power supply module includes a power filter and a noise suppressor;

[0077] The load simulation module is used to control the output load of the switching power supply to test the performance of the switching power supply under different load conditions;

[0078] The power supply monitoring module is used to monitor various parameters in real time during the power supply test process;

[0079] The fault detection module includes a power efficiency stability detection unit, a temperature efficiency detection unit, a ripple energy detection unit, and a comprehensive evaluation unit;

[0080] The power efficiency stability detection unit is used to quantify the stability of the efficiency of the switching power supply during the load change process. The temperature efficiency detection unit evaluates the impact of temperature change on the power supply stability by detecting the voltage and power data of the switching power supply at different temperatures. The ripple energy detection unit is used to detect the ripple voltage generated by the power supply in the high-frequency range and evaluate the interference of high-frequency noise on the power supply stability and the surrounding circuits. The comprehensive evaluation unit combines the detection results of the power efficiency stability detection unit, the temperature efficiency detection unit, and the ripple energy detection unit to comprehensively evaluate the switching power supply to determine the overall quality of the switching power supply.

[0081] The data storage module is used to store the data of the switching power supply test process and test results. The data storage module includes an on-body storage unit and a cloud storage unit. The on-body storage unit includes a mechanical hard disk.

[0082] More specifically, in this embodiment: by setting the test control module to control the start and stop of other modules through an embedded controller, testers can set test items and test conditions through the user interface, thereby realizing remote control, and using the power supply monitoring module to monitor various parameters in real time during the power supply test process and display them on the user interface, improving the automation level of switching power supply detection, saving the time of manual setting, improving the test efficiency, and at the same time ensuring the setting accuracy of the equipment.

[0083] When performing a power supply test after the preparation step is completed, the output load of the switching power supply is controlled by the load simulation module to test the performance of the switching power supply under different load conditions. The power efficiency stability detection unit in the fault detection module tests the stability of the efficiency of the switching power supply during the load change process. The power efficiency stability detection unit divides the load range into multiple load points and conducts a unified analysis by combining all load points, fully considering the power efficiency stability under different loads. Then, the temperature effect detection unit quantifies the impact of temperature changes on the power supply. By analyzing the efficiency, power loss data, and voltage data at high and low temperatures, the impact of temperature changes on the power supply can be evaluated, especially the change in efficiency and voltage offset at high temperatures, making the test of the switching power supply more in line with the actual situation and improving the accuracy of the switching power supply test.

[0084] Since high-frequency noise and ripple voltage have a greater impact on the performance of the power supply and the stability of the surrounding circuits, excessive noise can cause the power supply to work unstably and even cause system failures. The ripple energy detection unit can evaluate the noise characteristics of the switching power supply by detecting the ripple voltage in different frequency ranges, especially the noise in the high-frequency range, so as to conduct an accurate noise assessment of the power supply. Finally, the comprehensive evaluation unit combines the detection results of the power efficiency stability detection unit, the temperature effect detection unit, and the ripple energy detection unit to conduct a comprehensive evaluation of the switching power supply to determine the overall quality of the switching power supply, comprehensively evaluate the overall performance of the power supply, avoid the limitations of relying on a single test result, and further improve the accuracy of the switching power supply test.

[0085] Furthermore, the detection process of the power efficiency stability detection unit is as follows:

[0086]

[0087] Where E is the efficiency stability score;

[0088] X avg is the average efficiency;

[0089] X max is the maximum efficiency, and X min is the minimum efficiency;

[0090] σ x is the standard deviation of efficiency, representing the standard deviation of the efficiency values at all load points, used to quantify the fluctuation range of efficiency;

[0091] P out，i is the output power of the power supply at load point i;

[0092] P in is the input power of the power supply at load point i;

[0093] N is the number of load points. During the test where the load changes step by step from 10% to 100%, the arithmetic mean of the efficiencies at all load points. If taking a 10% step, the value of N is 10. When N is 1, it means the load is 10%, and so on. It can reflect the average energy efficiency level of the power supply under typical working conditions;

[0094] By normalization processing, the range is associated with the mean value to avoid the interference of the absolute efficiency differences of different power supplies on the results;

[0095] |X max -X min | represents the absolute value of the difference between the maximum efficiency and the minimum efficiency among all load points, reflecting the maximum deviation of the power supply efficiency within the load range. The larger |X max -X min | is, the worse the adaptability of the power supply to load changes;

[0096] Specifically, the efficiency stability score E is used to quantify the stability of the efficiency of the switching power supply during load changes. The larger the efficiency stability score E, the higher the efficiency and the smaller the fluctuation of the power supply during load changes, and the better the stability. The smaller the efficiency stability score E, the lower the efficiency and the larger the fluctuation of the power supply during load changes, and the worse the stability. Set the efficiency stability threshold of the efficiency stability score E as Y1. The setting standard of the efficiency stability threshold Y1 is determined according to the working environment of the switching power supply, the used load range, and the tolerance of efficiency fluctuations. When the efficiency stability score E is greater than the efficiency stability threshold Y1, the power supply is qualified, indicating small efficiency fluctuations and high stability. When the efficiency stability score E is less than the efficiency stability threshold Y1, the power supply is unqualified. By dividing the load range into multiple load points and conducting a unified analysis in combination with all load points, the efficiency stability of the power supply under different loads is fully considered to conform to the actual power supply usage situation and make the test results more comprehensive and accurate.

[0097] Furthermore, the detection process of the temperature efficiency detection unit is as follows:

[0098]

[0099] where TD is the temperature efficiency stability score;

[0100] ΔV out is the output voltage offset, indicating the absolute change in the output voltage of the switching power supply relative to the nominal value during the temperature change process;

[0101] ΔT is the temperature change amount, representing the set temperature change range in the test;

[0102] ΔV out,hot is the output voltage at high temperature;

[0103] ΔV out,cold is the low-temperature output voltage;

[0104] V nom is the nominal voltage;

[0105] X hot is the high-temperature efficiency, and X cold is the low-temperature efficiency;

[0106] The decrease in efficiency at high temperatures may be caused by factors such as increased switching losses and saturation of magnetic materials;

[0107] P loss,hot is the high-temperature power loss;

[0108] P loss,cold is the low-temperature power loss;

[0109] Power loss reflects the energy conversion efficiency of the power supply. The increase in loss at high temperatures may be caused by an increase in on-resistance and insufficient heat dissipation;

[0110] is a logarithmic term representing the ratio of power losses at high and low temperatures. If the high-temperature loss increases significantly, this value is much greater than 1, and through the addition operation, when P loss,hot = P loss,cold the logarithm is zero to ensure the validity of the formula;

[0111] The high-temperature power loss P loss,hot and the low-temperature power loss P loss,cold are obtained as follows:

[0112] P loss,hot = P in,hot - P out,hot

[0113] P loss,cold = P in,coldt - P out,cold

[0114] where P in,hot is the high-temperature input power, and P out,hot is the high-temperature output power;

[0115] P in,cold is the low-temperature input power, and P out,cold is the low-temperature output power;

[0116] Specifically, if the efficiency decreases significantly at high temperatures, that is, the denominator increases, then the temperature efficiency stability score TD decreases, indicating that the influence of temperature on efficiency dominates; conversely, if the voltage drift is severe, that is, the numerator increases, then the temperature efficiency stability score TD increases.

[0117] More specifically, the temperature efficiency stability score TD represents the degree of influence of temperature change on power supply stability. The larger the temperature efficiency stability score TD, the greater the influence of temperature change on voltage stability. The smaller the temperature efficiency stability score TD, the greater the influence on efficiency. The efficiency threshold of the temperature efficiency stability score TD is set as Y3. When the temperature efficiency stability score TD ≤ the efficiency threshold Y3, the power supply is qualified, indicating that the influence of temperature increase on performance can be ignored. When the temperature efficiency stability score TD > the efficiency threshold Y3, the power supply is unqualified, indicating that the temperature increase leads to a sharp drop in efficiency and excessive voltage offset. The influence of temperature change on the power supply is quantified by the temperature efficiency stability score TD. By analyzing the efficiency, power loss data, and voltage data at high and low temperatures, the influence of temperature change on the power supply can be evaluated, especially the change in efficiency and voltage offset at high temperatures, making the test of the switching power supply more in line with the actual situation and improving the accuracy of the switching power supply test.

[0118] The efficiency threshold Y3 is set according to the thermal test standard of electronic devices, requiring that for every 1°C increase, the power loss increase does not exceed 0.05% of the reference value, that is, the efficiency threshold Y3 is 0.05%.

[0119] Furthermore, the detection process of the ripple energy detection unit is as follows:

[0120]

[0121] Where R is the power supply noise hazard index;

[0122] V ripple (f) is the ripple voltage amplitude measured at frequency f, which can be scanned in the frequency band from 1 MHz to 10 MHz through the FFT function of a spectrum analyzer or oscilloscope, and the ripple voltage values at each frequency point are recorded;

[0123] By taking the frequency band from 1 MHz to 10 MHz, the potential interference of ripple components at different frequencies on the system can be quantified.

[0124] Low-frequency ripple is 1 - 5 MHz: Usually caused by the fundamental wave and harmonics of the switching frequency, which may lead to analog circuit offset.

[0125] High-frequency ripple is ≥5 MHz: May be generated by parasitic parameters and has a greater interference on high-speed digital circuits;

[0126] W(f) is the weight of frequency f. According to the differences in the sensitivity of the system to different frequencies, different weights are applied to ensure the effectiveness of the results;

[0127] The summation range is set to 1 MHz to 10 MHz, which can cover the typical switching frequencies of switching power supplies, avoid radio frequency interference, and enable the ripple energy detection unit to focus on the noise generated by the switching behavior of the switching power supply itself rather than external environmental interference. Set the first noise hazard threshold Y31 and the second noise hazard threshold Y32 of the power supply noise hazard index R. The first noise hazard threshold Y31 and the second noise hazard threshold Y32 are set according to the tolerance of high-frequency noise sensitive circuits in electromagnetic compatibility standards. When the power supply noise hazard index R ≤ the first noise hazard threshold Y31, the power supply is qualified, indicating that the high-frequency noise energy is low. When the temperature efficiency stability score TD ≥ the second efficiency threshold Y32, the power supply is unqualified, indicating that high-frequency noise interferes with adjacent circuits. By fully considering the impact of noise factors on the power supply quality during the testing of the switching power supply, the accuracy of power supply testing is further improved.

[0128] When Y31 ≤ R < Y32, it indicates that the high-frequency noise energy is in a critical state. At this time, adjust the power loss coefficient β, and the adjustment process is as follows:

[0129]

[0130] Where Nβ is the new power loss coefficient;

[0131] Since noise will interfere with the signal acquisition of the temperature sensor, resulting in distorted temperature control feedback, when Y31 ≤ R < Y32, use the new power loss coefficient Nβ to replace the initial power loss coefficient β, that is, dynamically adjust the power loss coefficient β to compensate for the error caused by high-frequency noise, improve the accuracy of the temperature efficiency stability score TD, and reduce the fluctuation impact of noise on the power supply.

[0132] Furthermore, the evaluation process of the comprehensive evaluation unit is as follows:

[0133]

[0134] Where ZS is the comprehensive power supply score;

[0135] E is the efficiency stability score;

[0136] Y1 is the efficiency stability threshold;

[0137] W1 is the influence coefficient of the efficiency stability score;

[0138] TD is the temperature efficiency stability score;

[0139] Y2 is the efficiency threshold;

[0140] W2 is the influence coefficient of the temperature efficiency stability score;

[0141] R is the power supply noise hazard index;

[0142] W3 is the influence coefficient of the power supply noise hazard index;

[0143] W1 + W2 + W3 = 1;

[0144] Specifically, even if the efficiency stability score, the temperature efficiency stability score TD, and the power supply noise hazard index R are all qualified but all close to the critical value, the power supply is in a sub-healthy state and still has a high potential safety hazard during use. Therefore, through comprehensive evaluation, the global stability of the power supply system can be reflected, the limitation of relying on a single test result can be avoided, and the accuracy of the switching power supply test can be further improved. Set the first comprehensive threshold of the power supply comprehensive score ZS as Z1 and the second comprehensive threshold as Z2. When the power supply comprehensive score ZS ≥ the comprehensive threshold Z1, it means the power supply is qualified. When the power supply comprehensive score ZS < the comprehensive threshold Z2, it means the power supply is unqualified. When Z2 ≤ ZS < Z1, it means the power supply is in a sub-healthy state and needs to be re-inspected. If it is still in a sub-healthy state after re-inspection, the power supply is determined to be unqualified.

[0145] Furthermore, the system alarm module is used to display different alarm lights through the user interface according to the detection results of the switching power supply, facilitating the testers to quickly understand the test results.

[0146] Specifically, the system alarm module displays different indicator lights according to the test results of the power supply efficiency stability detection unit, the temperature efficiency detection unit, the ripple energy detection unit, and the comprehensive evaluation unit. When the unit test is qualified, the user interface displays a green light. When it is unqualified, it displays a red light. When re-inspection is required, it displays an orange light, accompanied by a text description, facilitating the testers to quickly understand the switching power supply test situation and improving the test efficiency.

[0147] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An automatic test system for a switching power supply, characterized in that, It includes a test control module, an input power module, a load simulation module, a power monitoring module, a fault detection module, and a data storage module; The test control module is used to control the start and stop of other modules through an embedded controller. The test control module includes a user interface, and testers set test items and test conditions through the user interface; The load simulation module is used to control the output load of the switching power supply to test the performance of the switching power supply under different load conditions; The power monitoring module is used to monitor various parameters during the power test in real time and display them through the user interface; The fault detection module includes a power efficiency stability detection unit, a temperature efficiency detection unit, a ripple energy detection unit, and a comprehensive evaluation unit; The power efficiency stability detection unit is used to quantify the stability of the efficiency of the switching power supply during load change. The temperature efficiency detection unit evaluates the impact of temperature change on power supply stability by detecting voltage and power data of the switching power supply at different temperatures. The ripple energy detection unit is used to detect the ripple voltage generated by the power supply in the high-frequency range and evaluate the interference of high-frequency noise on power supply stability and surrounding circuits. The comprehensive evaluation unit comprehensively evaluates the switching power supply based on the detection results of the power efficiency stability detection unit, the temperature efficiency detection unit, and the ripple energy detection unit to determine the overall quality of the switching power supply.

2. The automatic test system for switching power supplies according to claim 1, wherein: The detection process of the power efficiency stability detection unit is as follows: Where E is the efficiency stability score; X avg is the average efficiency; X max is the maximum efficiency value, X min is the minimum efficiency value; σ x is the standard deviation of efficiency; P out，i is the output power of the point-of-load i power supply; P in is the input power of the point-of-load i power supply; N is the number of load points; The efficiency stability score E is used to quantify the stability of the efficiency of the switching power supply during load change. The larger the efficiency stability score E, the higher the efficiency and the smaller the fluctuation of the power supply during load change, and the better the stability. The smaller the efficiency stability score E, the lower the efficiency and the larger the fluctuation of the power supply during load change, and the worse the stability. The set efficiency stability threshold of the efficiency stability score E is Y1. When the efficiency stability score E is greater than the efficiency stability threshold Y1, the power supply is qualified, indicating small efficiency fluctuation and high stability. When the efficiency stability score E is less than the efficiency stability threshold Y1, the power supply is unqualified.

3. The automatic test system for switching power supplies according to claim 2, wherein: The detection process of the temperature efficiency detection unit is as follows: Where TD is the temperature efficiency stability score; ΔV out It is the output voltage offset, representing the absolute change in the output voltage of the switching power supply relative to the nominal value during the temperature change process; ΔT is the temperature change amount, representing the set temperature change range in the test; V out,hot is the high-temperature output voltage; V out,cold is the low-temperature output voltage; V nom is the nominal voltage; X hot is the high-temperature efficiency, X cold is the low-temperature efficiency; P loss,hot is the high-temperature power loss; P loss,cold is the low-temperature power loss; β is the power loss influence coefficient, with an initial value of 1; is a logarithmic term used to quantify the relative increase in power loss at high temperatures; High-temperature power loss P loss,hot and low-temperature power loss P loss,cold The derivation process is as follows: P loss,hot = P in,hot -P out,hot P loss,cold = P in,coldt -P out,cold where P in,hot is the high-temperature input power, and P out,hot is the high-temperature output power; P in,cold is the low-temperature input power, P out,cold is the low-temperature output power; The temperature efficiency stability score TD represents the degree of influence of temperature change on power supply stability. The larger the temperature efficiency stability score TD, the greater the influence of temperature change on voltage stability. The smaller the temperature efficiency stability score TD, the greater the influence on efficiency. The set efficiency threshold of the temperature efficiency stability score TD is Y2. When the temperature efficiency stability score TD ≤ efficiency threshold Y2, the power supply is qualified, indicating that the influence of temperature increase on performance can be ignored. When the temperature efficiency stability score TD > efficiency threshold Y2, the power supply is unqualified, indicating that the temperature increase causes a sharp drop in efficiency and excessive voltage offset.

4. The automatic test system for switching power supplies according to claim 3, wherein: The detection process of the ripple energy detection unit is as follows: Where R is the power supply noise hazard index; V ripple (f) is the measured ripple voltage amplitude at frequency f; W(f) is the weight of frequency f; MHz is megahertz, representing the unit symbol; Set the summation range to be from 1 MHz to 10 MHz, which can cover the typical switching frequencies of switching power supplies, avoid radio frequency interference, and enable the ripple energy detection unit to focus on the noise generated by the switching behavior of the switching power supply itself rather than external environmental interference. Set the first noise hazard threshold of the power supply noise hazard index R to be Y31, and the second noise hazard threshold Y32. When the power supply noise hazard index R ≤ the first noise hazard threshold Y31, the power supply is qualified, indicating that the high-frequency noise energy is low. When the temperature efficiency stability score TD ≥ the second efficiency threshold Y32, the power supply is unqualified, indicating that the high-frequency noise interferes with the adjacent circuit. When Y31 ≤ R < Y32, it indicates that the high-frequency noise energy is in a critical state. At this time, adjust the power loss coefficient β, and the adjustment process is as follows: Where Nβ is the new power loss coefficient; Since noise will interfere with the signal acquisition of the temperature sensor, resulting in distorted temperature control feedback, when Y31 ≤ R < Y32, use the new power loss coefficient Nβ to replace the initial power loss coefficient β, that is, dynamically adjust the power loss coefficient β to compensate for the error caused by high-frequency noise.

5. The automatic test system for a switching power supply according to claim 4, wherein: The evaluation process of the comprehensive evaluation unit is as follows: Where ZS is the comprehensive power supply score; E is the efficiency stability score; Y1 is the efficiency stability threshold; W1 is the influence coefficient of the efficiency stability score; TD is the temperature efficiency stability score; Y2 is the efficiency threshold; W2 is the influence coefficient of the temperature efficiency stability score; R is the power supply noise hazard index; W3 is the influence coefficient of the power supply noise hazard index; W1 + W2 + W3 = 1; Set the first comprehensive threshold of the power supply comprehensive score ZS to be Z1, and the second comprehensive threshold to be Z2. When the power supply comprehensive score ZS ≥ the first comprehensive threshold Z1, it indicates that the power supply is qualified. When the power supply comprehensive score ZS < the second comprehensive threshold Z2, it indicates that the power supply is unqualified. When the second comprehensive threshold Z2 ≤ the power supply comprehensive score ZS < the first comprehensive threshold Z1, it indicates that the power supply is in a sub-healthy state and needs to be re-inspected.

6. The automatic test system for switching power supplies according to claim 1, characterized in that: The input power supply module is used to provide the input power required for the switching power supply test. The input power supply module includes a power filter and a noise suppressor.

7. The automatic test system for switching power supply according to claim 5, wherein: Including a system alarm module, which is used to display different alarm lights through the user interface according to the detection results of the switching power supply, so as to facilitate the tester to quickly understand the test results.

8. The automatic test system for a switching power supply according to claim 1, wherein: The data storage module is used to store the switching power supply test process and test result data. The data storage module includes an on-body storage unit and a cloud storage unit. The on-body storage unit includes a mechanical hard disk.

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