A control and protection method for a parallel power electronic equipment testing system

Abstract

A control and protection method for a parallel power electronic equipment testing system is disclosed. This method provides fault early warning and protection for the parallel power electronic equipment testing system based on the load characteristics of the equipment under test and the allowable power of the parallel power electronic testing device. This control and protection method is applicable to parallel power electronic power testing systems, enabling the system to reduce the impact of faults on the testing device and equipment under test caused by abnormalities in some modules of the testing system through fault early warning and control protection, thereby minimizing the loss of testing system efficiency and equipment lifespan.

Description

Technical Field

[0001] This invention relates to the field of power electronic equipment control, and in particular to a control and protection method for a parallel power electronic equipment testing system. Background Technology

[0002] The power ratings of power electronic devices such as energy storage converters and photovoltaic inverters are increasing year by year, placing ever greater demands on the power ratings of parallel power electronic device testing systems. Due to the limitations of power device specifications, the power rating of a single unit in a parallel power electronic device testing system cannot be increased indefinitely; instead, power units must be connected in parallel to increase the overall power rating of the system. Parallel power electronic device testing systems have significantly more potential failure points than non-parallel systems, therefore, their stability is weaker.

[0003] When performing abnormal high-current tests on power electronic equipment (such as high / low current tests, overload tests, and grid adaptability tests), unordered shutdowns of the test devices and devices under test in parallel power electronic equipment test systems not only reduce testing efficiency but also shorten the lifespan of the test devices and devices under test. Parallel operation can easily damage the test devices and devices under test. This control and protection method can effectively reduce the impact of faults in the test devices and devices under test caused by abnormalities in some modules of the parallel power electronic equipment test system, thus reducing the loss of operating efficiency and equipment lifespan of the parallel power electronic equipment test system.

[0004] Therefore, it is essential to provide a control and protection method for a parallel power electronic equipment testing system to address the shortcomings of existing technologies. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a control and protection method for a parallel power electronic device testing system. This control and protection method is applicable to parallel power electronic power testing systems, enabling the system to reduce the impact of faults in the testing equipment and the device under test caused by abnormalities in some modules of the testing system through fault warning and control protection, thereby minimizing the loss of testing system efficiency and equipment lifespan.

[0006] The above-mentioned objectives of the present invention are achieved through the following technical measures:

[0007] A control and protection method for a parallel power electronic equipment testing system is provided. The method provides fault early warning for the parallel power electronic equipment testing system based on the load characteristics of the equipment under test and the allowable power of the parallel power electronic testing device. The parallel power electronic equipment testing system includes the equipment under test and the parallel power electronic testing device.

[0008] The parallel power electronics testing device includes a separate AC testing device, a separate DC testing device, and an AC / DC testing device; the AC / DC testing device is composed of an AC testing device and a DC testing device.

[0009] The AC testing device includes parallel and independently operating AC minimum power units, wherein the grid side is connected in parallel to the external power grid and the machine side is connected in parallel to the device under test.

[0010] The DC-type test device includes parallel and independently operating DC minimum power units, wherein the grid side is connected in parallel to the external power grid and the machine side is connected in parallel to the device under test.

[0011] Preferably, the load characteristics of the tested equipment are calculated using equation (1);

[0012] P load (t1)≤P m ,t m-1 <t1≤t m ...Equation (1);

[0013] Among them, P load (t1) represents the load power, m is a fixed parameter determined by the detection item and m is a non-zero natural number, P m Fixed parameters determined for the test item and P m For t m-1 to t m The maximum load power corresponding to the time, t1 is the test run time of the device under test in the parallel power electronic equipment test system; t m The running time for the tested equipment to complete the testing items and t m Fixed parameters determined by the test items, t m-1 For load power P m-1 The cutoff time for power operation.

[0014] Preferably, the maximum allowable power of the above-mentioned AC test device is expressed by equation (2);

[0015] P AC_source (t2)=P AC_source_unit (t2)×x AC ...Equation (2);

[0016] Among them, P AC_source_unit(t2) represents the maximum allowable power of the smallest AC power unit, x AC t2 represents the minimum number of AC power units required for the AC-type test device to operate normally. AC_source_unit (t2) Longest running time.

[0017] Preferably, the above-mentioned maximum permissible power P AC_source_unit (t2) is expressed by equation (3):

[0018]

[0019] Where n1, P AC_n1 and t AC_n1 These are all fixed parameters of the AC-type test device, where n1 is a non-zero natural number, and t AC_1 For AC source with power P AC_1 The longest allowed time.

[0020] Preferably, the maximum allowable power of the above-mentioned DC-type test device is expressed by equation (4);

[0021] P DC_source (t3)=P DC_source_unit (t3)×x DC ...Equation (4);

[0022] Among them, P DC_source_unit (t3) represents the maximum allowable power of the DC minimum power unit; x AC t3 represents the minimum number of DC power units required for normal operation of a DC-type test device. DC_source_unit (t3) Longest running time.

[0023] Preferably, the above-mentioned maximum permissible power P DC_source_unit (t3) is expressed by equation (5):

[0024]

[0025] Among them, n2, P DC_n2 and t DC_n2 All are fixed parameters of a DC-type test device, and n2 is a non-zero natural number, t DC_1 A DC source with power P DC_1 The longest allowed time, t DC_(n2-1) A DC source with power P DC_(n2-1) The longest allowed time.

[0026] Preferably, the maximum allowable power of the above AC / DC testing device is expressed by equation (6):

[0027]

[0028] Among them, P AC&DC_source(t) is the maximum allowable power of the AC / DC test device.

[0029] In a separate AC test device, the following steps are carried out:

[0030] A1. Determine whether the device under test has completed the test items: Let the test running time of the device under test be t1 = t0, where t0 is the actual test running time of the device under test and t0 is a constant. Then compare t0 with t m If t0 < t m , it means that the test items are not completed and proceed to A2; if t0 ≥ t m , it means that the test items are completed and proceed to A4;

[0031] A2. Predict the load of the device under test: Compare t0 with t1, …, t m respectively, determine the time period of the load of the device under test on the load characteristic curve at t0, and make t k-1 ≤ t0 < t k , where k is a non-zero natural number and k < m, and k is a constant determined by t0 and the load characteristic P load (t1). The start and end times of the load power corresponding to t0 are t k-1 to t k ; Obtain the predicted load of the device under test during the test time t0 < t1 ≤ t load as m Then proceed to A3;

[0032] A3. Early warning judgment of the AC test device: Compare the predicted load P load (t1) of the device under test with the maximum allowable power P AC_source (t2) of the AC test device; When the predicted load P load (t1) of the device under test is greater than the maximum allowable power P AC_source (t2) of the AC test device, that is, and do not hold, then return to A5; When the predicted load P load (t1) of the device under test is less than or equal to the maximum allowable power P AC_source

[0033] (t2) of the AC test device, that is, and hold, then return to A1, where P k is the power of the predicted load of the device under test from time t k-1 to t k , and P m is the power of the predicted load of the device under test from time t m-1 to t​m Power;

[0034] A4. Send a test normal completion message to the parallel power electronic equipment test system, send a shutdown command to the device under test, and send a shutdown command to the AC test device after the device under test shuts down;

[0035] A5. Send a test device fault warning message to the parallel power electronic equipment test system, send a shutdown command to the device under test, and send a shutdown command to the AC test device after the device under test shuts down.

[0036] In a separate DC test device, perform the following steps:

[0037] B1. Determine whether the device under test has completed the test items: Let the test running time t1 of the device under test = t0, and t0 is the actual test running time of the device under test and t0 is a constant. Then compare t0 with t m Magnitude. When t0 < t m , it means that the test item is not completed and enter B2; when t0 ≥ t m It means that the test item is completed and enter B4;

[0038] B2. Predict the load of the device under test: Compare t0 with t1, ……, t m Magnitude, determine the time period when the load of the device under test is located on the load characteristic curve at t0, and make t k-1 ≤ t0 < t k , where k is a non - zero natural number and k < m, and k is a constant determined by t0 and the load characteristic P load (t1). Obtain the predicted load of the device under test at the test time t0 < t1 ≤ t load As m Then enter A3; Then enter A3;

[0039] B3. DC test device warning judgment: Compare the predicted load P load (t1) of the device under test with the maximum allowable power P DC_source (t3) of the DC test device; When the predicted load P load (t1) of the device under test is greater than the maximum allowable power P DC_source (t3) of the DC test device, that is And Does not hold, then return to B5; When the predicted load P load (t1) of the device under test is less than or equal to the maximum allowable power P DC_source (t3) of the DC test device, that is And Holds, then return to B1;

[0040] B4. Send the information indicating that the test is completed successfully to the parallel - type power electronic equipment test system, send a shutdown command to the device under test, and send a shutdown command to the DC - type test device after the device under test shuts down.

[0041] B5. Send a fault warning message of the test device to the series - parallel - type power electronic equipment test system, send a shutdown command to the device under test, and send a shutdown command to the DC - type test device after the device under test shuts down.

[0042] In the AC - DC type test device, the following steps are carried out:

[0043] C1. Determine whether the device under test has completed the test items: Let the test running time of the device under test \(t1 = t0\), where \(t0\) is the actual test running time of the device under test and \(t0\) is a constant, and then compare \(t0\) with \(t\) m When \(t0 < t\) m , it means that the test items have not been completed and enter C2; when \(t0\geq t\) m , it means that the test items have been completed and enter C5.

[0044] C2. Predict the load of the device under test: Compare \(t0\) with \(t1,\cdots,t\) m respectively, determine the time period on the load characteristic curve where the load of the device under test is located at \(t0\), and make \(t\) k-1 \(\leq t0 < t\) k , where \(k\) is a non - zero natural number and \(k < m\), and \(k\) is a constant determined by \(t0\) and the load characteristic \(P\) load (t1). Obtain the predicted load of the device under test at the test time \(t0 < t1\leq t\) load as m , and then enter C3. Then enter C3.

[0045] C3. Early warning judgment of the AC - type test device in the AC - DC type test device: Compare the predicted load \(P\) load (t1) of the device under test with the maximum allowable power \(P\) AC_source (t2) of the AC - type test device in the AC - DC type test device; when the predicted load \(P\) load (t1) of the device under test is greater than the maximum allowable power \(P\) AC_source (t2) of the AC - type test device in the AC - DC type test device, that is and do not hold, then return to C6; when the predicted load \(P\) load (t1) of the device under test is less than or equal to the maximum allowable power \(P\) AC_source (t2) of the AC - type test device in the AC - DC type test device, that is and If true, return to C4;

[0046] C4. The DC testing device in the AC / DC testing device provides early warning judgment: It compares the predicted load P of the device under test. load (t1) and the maximum allowable power P of the DC test device in the AC / DC test device. DC_source The magnitude of (t3); when the predicted load P of the tested equipment load (t1) is greater than the maximum allowable power P of the DC test device in the AC / DC test device. DC_source (t3) is when and If not true, return to C7; when the predicted load P of the device under test... load (t1) is less than or equal to the maximum allowable power P of the DC test device in the AC / DC test device. DC_source (t3) is when and If true, return to C1;

[0047] C5. Send a test completion message to the parallel power electronic equipment test system, send a shutdown command to the device under test, and after the device under test shuts down, send a shutdown command to the AC / DC test device.

[0048] C6. Send AC test device fault warning information to the parallel power electronic equipment test system, send a shutdown command to the device under test, and send a shutdown command to the AC / DC test device after the device under test shuts down.

[0049] C7. Send DC test device fault warning information to the parallel power electronic equipment test system, send a shutdown command to the device under test, and send a shutdown command to the AC / DC test device after the device under test shuts down.

[0050] This invention discloses a control and protection method for a parallel power electronic equipment testing system. Based on the load characteristics of the equipment under test (DUT) and the allowable power of the parallel power electronic testing device, the method provides fault early warning for the parallel power electronic equipment testing system. The parallel power electronic equipment testing system includes the DUT and the parallel power electronic testing device. The parallel power electronic testing device can be a separate AC testing device, a separate DC testing device, or an AC / DC testing device. The AC / DC testing device consists of an AC testing device and a DC testing device. The AC testing device includes parallel and independently operating AC minimum power units, with the grid side connected in parallel to the external power grid and the machine side connected in parallel to the DUT. The DC testing device includes parallel and independently operating DC minimum power units, with the grid side connected in parallel to the external power grid and the machine side connected in parallel to the DUT. When performing abnormal high-current tests on power electronic equipment, such as high-voltage and low-voltage switching, overload, and grid adaptability tests, unordered failures of the test devices and devices under test (DUTs) in the test system not only reduce testing efficiency but also shorten their lifespan. Parallel operation can easily damage the test devices and DUTs. The control and protection method of the parallel power electronic equipment test system of this invention can effectively reduce the impact of faults in the test devices and DUTs caused by abnormalities in some test system modules, thus reducing the loss of test system efficiency and equipment lifespan. This control and protection method for the parallel power electronic equipment test system is applicable to parallel power electronic power test systems, enabling the parallel power electronic power test system to reduce the impact of faults in the test devices and DUTs caused by abnormalities in some test system modules through fault warning and control protection, thereby reducing the loss of test system efficiency and equipment lifespan. Attached Figure Description

[0051] The invention will be further described with reference to the accompanying drawings, but the contents of the drawings do not constitute any limitation on the invention.

[0052] Figure 1 This is a flowchart of a control and protection method for a parallel power electronic equipment testing system.

[0053] Figure 2 This is a schematic diagram illustrating an application scenario for a standalone AC-type testing device.

[0054] Figure 3 This is a schematic diagram of an application scenario for a standalone DC-type test device.

[0055] Figure 4 This is a schematic diagram illustrating the application scenarios of AC / DC testing equipment. Detailed Implementation

[0056] The technical solution of the present invention will be further described in conjunction with the following embodiments.

[0057] Example 1

[0058] A control and protection method for a parallel power electronic equipment testing system, such as Figure 1 A control and protection method for fault early warning of a parallel power electronic equipment test system is proposed, based on the load characteristics of the equipment under test and the allowable power of the parallel power electronic test device. The parallel power electronic equipment test system includes the equipment under test and the parallel power electronic test device.

[0059] Parallel power electronics testing devices include standalone AC testing devices, standalone DC testing devices, and AC / DC testing devices.

[0060] like Figure 2 The AC test device includes AC minimum power units that are connected in parallel and can operate independently, wherein the grid side is connected in parallel to the external power grid and the machine side is connected in parallel to the device under test.

[0061] like Figure 3 The DC test device includes a DC minimum power unit that is connected in parallel and can operate independently, wherein the grid side is connected in parallel to the external power grid and the machine side is connected in parallel to the device under test.

[0062] The AC / DC testing device consists of an AC testing device and a DC testing device, such as... Figure 4 .

[0063] It should be noted that in AC / DC testing devices, the AC testing device is the same as a standalone AC testing device, and the DC testing device is the same as a standalone DC testing device.

[0064] The load characteristics of the equipment under test are calculated using equation (1);

[0065] P load (t1)≤P m ,t m-1 <t1≤t m ...Equation (1);

[0066] Among them, P load (t1) represents the load power, m is a fixed parameter determined by the detection item and m is a non-zero natural number, P m Fixed parameters determined for the test item and P m For t m-1 to t m The maximum load power corresponding to the time, t1 is the test run time of the device under test in the parallel power electronic equipment test system; t m The running time for the tested equipment to complete the testing items and t m Fixed parameters determined by the test items, t m-1 For load power Pm-1 The cutoff time for power operation.

[0067] It should be noted that the load characteristic of the tested equipment in equation (1) represents the operating time t1 of the tested equipment within t... m-1 to t m During the time period, the load power P load (t1) is less than or equal to P m .

[0068] The maximum permissible power of the AC-type test device is expressed by equation (2);

[0069] P AC_source (t2)=P AC_source_unit (t2)×x AC ...Equation (2);

[0070] Among them, P AC_source_unit (t2) represents the maximum allowable power of the smallest AC power unit, x AC t2 represents the minimum number of AC power units required for the AC-type test device to operate normally. AC_source_unit (t2) Longest running time.

[0071] It should be noted that the maximum permissible power of the AC test device in equation (2) represents the maximum permissible power P of the test device. AC_source The longest running time of (t2) does not exceed t2.

[0072] Maximum allowable power P AC_source_unit (t2) is expressed by equation (3):

[0073]

[0074] Where n1, P AC_n1 and t AC_n1 These are all fixed parameters of the AC-type test device, where n1 is a non-zero natural number, and t AC_1 For AC source with power P AC_1 The longest allowed time.

[0075] It should be noted that equation (3) represents the maximum allowable power P. AC_source_unit (t2) Maximum permissible power P of the minimum power unit in AC AC_n1 The longest running time does not exceed t AC_n1 .

[0076] The maximum allowable power of the DC-type test device is expressed by equation (4);

[0077] P DC_source (t3)=P DC_source_unit (t3)×x DC ...Equation (4);

[0078] Among them, P DC_source_unit (t3) represents the maximum allowable power of the DC minimum power unit; x AC t3 represents the minimum number of DC power units required for normal operation of a DC-type test device. DC_source_unit (t3) Longest running time.

[0079] It should be noted that equation (4) represents the maximum allowable power P of the DC-type test device. DC_source The longest running time of (t3) does not exceed t3.

[0080] Maximum allowable power P DC_source_unit (t3) is expressed by equation (5):

[0081]

[0082] Among them, n2, P DC_n2 and t DC_n2 All are fixed parameters of a DC-type test device, and n2 is a non-zero natural number, t DC_1 A DC source with power P DC_1 The longest allowed time, t DC_(n2-1) A DC source with power P DC_(n2-1) The longest allowed time.

[0083] It should be noted that equation (4) represents the maximum allowable power P. DC_source_unit (t3) Maximum allowable power P of DC minimum power unit DC_n2 The longest running time does not exceed t DC_n2 .

[0084] The maximum permissible power of the AC / DC test device is expressed by equation (6):

[0085]

[0086] Among them, P AC&DC_source (t) represents the maximum permissible power of the AC / DC test device.

[0087] It should be noted that the calculation methods for the maximum allowable power of AC test devices and the maximum allowable power of DC test devices are the same as those for separate AC test devices and separate DC test devices.

[0088] In a separate AC-type test setup, follow these steps:

[0089] A1. Determining whether the device under test (DUT) has completed the test items: Let the test run time of the DUT be t1 = t0, where t0 is the actual test run time of the DUT and t0 is a constant. Then compare t0 with t1.m When t0 < t, the size of m indicates that the test item is not completed and proceeds to A2; when t0 ≥ t m it indicates that the test item is completed and proceeds to A4;

[0090] A2. Predict the load of the device under test: Compare t0 with t1, …, t m to determine the time period on the load characteristic curve where the load of the device under test is located at t0, and make t k-1 ≤ t0 < t k , where k is a non - zero natural number and k < m, and k is a constant determined by t0 and the load characteristic P load (t1), where the start and end times of the load power corresponding to the time t0 are t k-1 to t k ; Obtain the predicted load of the device under test at the test time t0 < t1 ≤ t load from the load characteristic P m (t1) of the device under test as Then proceed to A3;

[0091] A3. Early warning judgment of the AC - type test device: Compare the predicted load P <on>0000159< / on>(t1) of the device under test with the maximum allowable power P <on>0000160< / on>(t2) of the AC - type test device; When the predicted load P <on>0000161< / on>(t1) of the device under test is greater than the maximum allowable power P <on>0000162< / on>(t2) of the AC - type test device, that is <on>0000427< / on>and <on>0000428< / on>do not hold, then return to A5; When the predicted load P <on>0000163< / on>(t1) of the device under test is less than or equal to the maximum allowable power P <on>0000164< / on><on>0000429< / on><on>0000430< / on>(t2) of the AC - type test device, that is <on>0000431< / on>and <on>0000432< / on>hold, then return to A1, where P <on>0000165< / on>is the power of the predicted load of the device under test at time t <on>0000166< / on>to t <on>0000167< / on>, and P <on>0000168< / on>is the power of the predicted load of the device under test at time t <on>0000169< / on>to t <on>0000170< / on>; <on>0000433< / on><on>0000434< / on>[[ID=6,6]]A4. Send a message indicating that the test is completed successfully to the parallel - type power electronic device test system, send a shutdown command to the device under test, and after the device under test shuts down, send a shutdown command to the AC - type test device; <on>00,00435< / on><on>0000436< / on>A5. Send a fault warning message of the test device to the parallel power electronic equipment test system, send a shutdown command to the device under test, and send a shutdown command to the AC test device after the device under test shuts down.

[0095] In a separate DC test device, the following steps are carried out:

[0096] B1. Determine whether the device under test has completed the test items: Let the test running time t1 of the device under test be t0, and t0 is the actual test running time of the device under test and t0 is a constant. Then compare t0 with t m When t0 < t m it means that the test items have not been completed and enter B2; when t0 ≥ t m it means that the test items have been completed and enter B4;

[0097] B2. Predict the load of the device under test: Compare t0 with t1, ……, t m respectively to determine the time period when the load of the device under test is located on the load characteristic curve at t0, and make t k-1 ≤ t0 < t k , where k is a non-zero natural number and k < m, and k is a constant determined by t0 and the load characteristic P load (t1). Obtain the predicted load of the device under test at the test time t0 < t1 ≤ t load as m Then enter A3; Then enter A3;

[0098] B3. DC test device warning judgment: Compare the predicted load P load (t1) of the device under test with the maximum allowable power P DC_source (t3) of the DC test device; when the predicted load P load (t1) of the device under test is greater than the maximum allowable power P DC_source (t3) of the DC test device, that is and do not hold, then return to B5; when the predicted load P load (t1) of the device under test is less than or equal to the maximum allowable power P DC_source (t3) of the DC test device, that is and hold, then return to B1;

[0099] B4. Send a message indicating that the test has been successfully completed to the parallel power electronic equipment test system, send a shutdown command to the device under test, and send a shutdown command to the DC test device after the device under test shuts down;

[0100] B5. Send a test device fault warning message to the series-connected power electronic device test system, send a shutdown command to the device under test, and send a shutdown command to the DC test device after the device under test shuts down.

[0101] In the AC-DC test device, the following steps are carried out:

[0102] C1. Determine whether the device under test has completed the test items: Let the test running time t1 of the device under test = t0, where t0 is the actual test running time of the device under test and t0 is a constant, and then compare t0 with t m When t0 < t m it means that the test items have not been completed and enter C2; when t0 ≥ t m it means that the test items have been completed and enter C5;

[0103] C2. Predict the load of the device under test: Compare t0 with t1, ……, t m respectively to determine the time period of the load of the device under test at t0 on the load characteristic curve, and make t k-1 ≤ t0 < t k , where k is a non-zero natural number and k < m, and k is a constant determined by t0 and the load characteristic P load (t1). Obtain the predicted load of the device under test at the test time t0 < t1 ≤ t load according to the load characteristic P m (t1) of the device under test as and then enter C3;

[0104] C3. Early warning judgment of the AC test device in the AC-DC test device: Compare the predicted load P load (t1) of the device under test with the maximum allowable power P AC_source (t2) of the AC test device in the AC-DC test device; when the predicted load P load (t1) of the device under test is greater than the maximum allowable power P AC_source (t2) of the AC test device in the AC-DC test device, that is and do not hold, then return to C6; when the predicted load P load (t1) of the device under test is less than or equal to the maximum allowable power P AC_source (t2) of the AC test device in the AC-DC test device, that is and hold, then return to C4;

[0105] C4. Early warning judgment of the DC test device in the AC-DC test device: Compare the predicted load P load(t1) and the maximum allowable power P of the DC test device in the AC / DC test device. DC_source The magnitude of (t3); when the predicted load P of the tested equipment load (t1) is greater than the maximum allowable power P of the DC test device in the AC / DC test device. DC_source (t3) is when and If not true, return to C7; when the predicted load P of the device under test... load (t1) is less than or equal to the maximum allowable power P of the DC test device in the AC / DC test device. DC_source (t3) is when and If true, return to C1;

[0106] C5. Send a test completion message to the parallel power electronic equipment test system, send a shutdown command to the device under test, and after the device under test shuts down, send a shutdown command to the AC / DC test device.

[0107] C6. Send AC test device fault warning information to the parallel power electronic equipment test system, send a shutdown command to the device under test, and send a shutdown command to the AC / DC test device after the device under test shuts down.

[0108] C7. Send DC test device fault warning information to the parallel power electronic equipment test system, send a shutdown command to the device under test, and send a shutdown command to the AC / DC test device after the device under test shuts down.

[0109] When performing abnormal high-current tests on power electronic equipment, such as high-voltage and low-voltage switching, overload, and grid adaptability tests, unordered failures of the test devices and devices under test (DUTs) in the test system not only reduce testing efficiency but also shorten their lifespan. Parallel operation can easily damage the test devices and DUTs. The control and protection method of the parallel power electronic equipment test system of this invention can effectively reduce the impact of faults in the test devices and DUTs caused by abnormalities in some test system modules, thus reducing the loss of test system efficiency and equipment lifespan. This control and protection method for the parallel power electronic equipment test system is applicable to parallel power electronic power test systems, enabling the parallel power electronic power test system to reduce the impact of faults in the test devices and DUTs caused by abnormalities in some test system modules through fault warning and control protection, thereby reducing the loss of test system efficiency and equipment lifespan.

[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A control and protection method for a parallel power electronic equipment testing system, characterized in that: Based on the load characteristics of the equipment under test and the allowable power of the parallel power electronic testing device, a control and protection method for fault early warning of the parallel power electronic equipment testing system is proposed. The parallel power electronic equipment testing system includes the device under test and the parallel power electronic testing device. The parallel power electronics testing device includes a separate AC testing device, a separate DC testing device, and an AC / DC testing device; the AC / DC testing device is composed of an AC testing device and a DC testing device. The AC testing device includes parallel AC minimum power units that can operate independently, wherein the grid side is connected in parallel to the external power grid and the machine side is connected in parallel to the device under test. The DC test device includes parallel and independently operating DC minimum power units, wherein the grid side is connected in parallel to the external power grid and the machine side is connected in parallel to the device under test; The load characteristics of the tested equipment are calculated by equation (1); ...Equation (1); in, For load power, m The fixed parameters determined by the test items and m It is a non-zero natural number. P m Fixed parameters determined for the test items and P m for t m-1 arrive t m The maximum load power corresponding to the time. t 1 The test run time of the device under test in the parallel power electronic equipment test system; t m The running time for the tested equipment to complete the testing items and t m Fixed parameters determined by the test items, t m-1 For load power P m-1 Power operation cutoff time; The maximum permissible power of the AC-type test device is expressed by equation (2); ...Equation (2); in, The maximum permissible power of the smallest AC power unit. This represents the minimum number of AC power units required for the AC-type test device to operate normally. t 2 for Longest runtime; The maximum allowable power Equation (3) represents: ...Equation (3); in n1 , and All of these are fixed parameters of the AC-type test device, among which n1 Non-zero natural numbers, t AC_1 AC source with power as P AC_1 The longest allowed time; The maximum allowable power Equation (5) represents: ...Equation (5); in, n2 , and All of these are fixed parameters for DC-type test equipment, and n2 It is a non-zero natural number. t DC_1 DC source with power as P DC_1 The longest allowed time, t DC_(n2-1) DC source with power as P DC_(n2-1) The longest allowed time; In a separate AC-type test setup, follow these steps: A1. Determine if the device under test has completed the test items: Set the test run time for the device under test. ,and t 0 The actual test run time of the device under test and t 0 Set to a constant, then compare. t 0 and t m The size, when t 0 ＜t m If the test result is incomplete, proceed to A2; when... t 0 ≥t m This indicates that the test project is complete and proceeds to A4; A2. Predict the load on the tested equipment: Compare the following: t 0 and t 1 , …… , t m Size, determine t 0 The time period during which the load of the tested equipment is located on the load characteristic curve, and making t k-1 ≤ t 0 ＜t k , k are non-zero natural numbers and k < m ,in k Depend on t 0 and load characteristics A definite constant, where t 0 The start and end times of the load power corresponding to the given time are: t k-1 to t k Based on the load characteristics of the equipment under test Obtain the device under test during the test time The predicted load is Then proceed to A3; A3. Early warning judgment of AC-type test equipment: Compare the predicted load of the tested equipment. Maximum permissible power of AC test equipment Size; when the predicted load of the device under test Greater than the maximum permissible power of the AC test device At that time, that is and If the condition is not met, return to A5; when the predicted load of the device under test is... Less than or equal to the maximum permissible power of the AC test device At that time, that is and If true, return A1, where P k Predict the load of the device under test in time t k-1 to t k power, P m Predict the load of the device under test in time t m-1 to t m The power; A4. Send test completion information to the parallel power electronic equipment test system, send a shutdown command to the device under test, and send a shutdown command to the AC test device after the device under test shuts down. A5. Send test device fault warning information to the parallel power electronic equipment test system, send a shutdown command to the device under test, and send a shutdown command to the AC test device after the device under test shuts down.

2. The control and protection method for the parallel power electronic equipment testing system according to claim 1, characterized in that: The maximum allowable power of the DC-type test device is expressed by equation (4); ...Equation (4); in, This represents the maximum allowable power of the minimum DC power unit. This represents the minimum number of DC power units required for the DC-type test device to operate normally. t 3 for Longest runtime.

3. The control and protection method for the parallel power electronic equipment testing system according to claim 2, characterized in that: The maximum allowable power of the AC / DC test device is expressed by equation (6): ...Equation (6); in, This is the maximum permissible power for AC / DC type test equipment.

4. The control and protection method for the parallel power electronic equipment testing system according to claim 3, characterized in that, In a separate DC-type test setup, follow these steps: B1. Determine if the device under test has completed the test items: Set the test run time for the device under test. ,and The actual test run time of the device under test and Set to a constant, then compare. t 0 and t m The size, when If the test result is not complete, proceed to B2; when... This indicates that the test project is complete and proceeds to B4; B2. Predict the load on the tested equipment: Compare the following: t 0 and t 1 , …… , t m Size, determine t 0 The time period during which the load of the tested equipment is located on the load characteristic curve, and making t k-1 ≤ t 0 ＜t k , k are non-zero natural numbers and k < m ,in k Depend on t 0 and load characteristics A definite constant, based on the load characteristics of the equipment under test. Obtain the device under test during the test time The predicted load is Then proceed to A3; B3. Early Warning Judgment of DC Type Test Device: Compare with Predicted Load of the Test Equipment Maximum permissible power of DC type test equipment Size; when the predicted load of the device under test Greater than the maximum permissible power of the DC type test device At that time, that is and If the condition is not met, return to B5; when the predicted load of the device under test is... Less than or equal to the maximum permissible power of the DC type test device At that time, that is and If true, return to B1; B4. Send a test completion message to the parallel power electronic equipment test system, send a shutdown command to the device under test, and send a shutdown command to the DC test device after the device under test shuts down. B5. Send test device fault warning information to the DC-parallel type power electronic equipment test system, send a shutdown command to the device under test, and send a shutdown command to the DC type test device after the device under test shuts down.

5. The control and protection method for the parallel power electronic equipment testing system according to claim 4, characterized in that, The following steps are performed in the AC / DC testing device: C1. Determine if the device under test has completed the test items: Set the test run time for the device under test. ,and t 0 The actual test run time of the device under test and t 0 Set to a constant, then compare. t 0 and t m The size, when If the test result is not completed, it indicates that the test item has not been completed and proceeds to C2; when This indicates that the test project is complete and proceeds to C5; C2. Predict the load on the tested equipment: Compare the following: t 0 and t 1 , …… , t m Size, determine t 0 The time period during which the load of the tested equipment is located on the load characteristic curve, and making t k-1 ≤ t 0 ＜t k , k are non-zero natural numbers and k < m ,in k Depend on t 0 and load characteristics A definite constant, based on the load characteristics of the equipment under test. Obtain the device under test during the test time The predicted load is Then enter C3; C3. Early warning judgment of the AC type test device in the AC / DC type test device: compare the predicted load of the tested equipment. The maximum allowable power of the AC type test device in the AC / DC type test device. Size; when the predicted load of the device under test Greater than the maximum allowable power of the AC type test device in the AC / DC type test device. At that time, that is and If the condition is not met, return to C6; when the predicted load of the device under test is... Less than or equal to the maximum allowable power of the AC type test device in the AC / DC type test device. At that time, that is and If true, return to C4; C4. The DC testing device in the AC / DC testing device makes an early warning judgment by comparing the predicted load of the device under test. The maximum allowable power of the DC type test device in the AC / DC type test device. Size; when the predicted load of the device under test Greater than the maximum allowable power of the DC type test device in the AC / DC type test device. At that time, that is and If the condition is not met, return to C7; when the predicted load of the device under test is... Less than or equal to the maximum allowable power of the DC type test device in the AC / DC type test device. At that time, that is and If true, return to C1; C5. Send test completion information to the parallel power electronic equipment test system, send a shutdown command to the device under test, and send a shutdown command to the AC / DC test device after the device under test shuts down. C6. Send AC test device fault warning information to the parallel power electronic equipment test system, send a shutdown command to the device under test, and send a shutdown command to the AC / DC test device after the device under test shuts down. C7. Send DC test device fault warning information to the parallel power electronic equipment test system, send a shutdown command to the device under test, and send a shutdown command to the AC / DC test device after the device under test shuts down.

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