Insulation test method, device and equipment for flexible direct-current converter valve power module

Abstract

The application relates to a kind of insulation test method, device and equipment of flexible direct current converter valve power module, the method comprises obtaining the power component to be tested and test type;According to power component and test type, determine test condition;According to test condition, insulation test is carried out to power component using up method and up-down method, and withstand voltage is obtained;Using correction coefficient, withstand voltage is corrected to obtain the voltage of power component working in high altitude scene.The method can be used to test the insulation of power module or power device in flexible direct current converter valve, and the withstand voltage is obtained, and then the correction coefficient method is used to obtain the voltage of power component working in high altitude scene, which can guide the insulation design of power component used in high altitude scene, and solve the technical problem of lack of insulation test of flexible direct current converter valve used in high altitude in the existing insulation test method of flexible direct current converter valve.

Description

Technical Field

[0001] This invention relates to the field of flexible DC converter valve power module technology, and in particular to an insulation testing method, apparatus and equipment for flexible DC converter valve power modules. Background Technology

[0002] Flexible DC transmission technology is one of the key technologies for building new power systems. It is widely used in new energy transmission fields such as long-distance, high-capacity power transmission, medium- and low-voltage DC distribution, offshore wind power, and high-altitude desert solar power generation. Flexible DC converter valves are important devices in flexible DC transmission systems that achieve AC-DC conversion. In high-altitude applications, atmospheric parameters change with altitude, affecting the electrical external insulation discharge voltage of the flexible DC converter valve's core components (such as power devices), thus impacting their safe and reliable operating voltage.

[0003] Changes in air pressure are closely related to changes in altitude; generally, atmospheric pressure decreases roughly linearly with increasing altitude. As atmospheric pressure decreases, the mean free path of charged particles in the air increases, leading to stronger collisional ionization during collisions with gas molecules. This makes gap discharge more likely to occur in flexible DC transmission equipment. Humidity, a physical quantity reflecting the dryness of the air, decreases approximately exponentially with increasing altitude. Fewer water molecules in the air result in more free electrons, enhancing gap ionization and reducing gap discharge voltage. Therefore, for high-altitude applications, if the electrical clearance of the core components of the flexible DC converter valve is too small, gap discharge may occur, affecting equipment operation.

[0004] Currently, there are no flexible DC projects applied in high-altitude (above 1000m) areas. To meet the needs of high-altitude applications, insulation tests should be conducted on the power devices in the flexible DC converter valves to determine the service margins of electrical clearances and creepage distances for various types of power devices at high altitudes. This will guide the design of flexible DC converter valves in the project and ensure safe and reliable use. Summary of the Invention

[0005] This invention provides an insulation testing method, apparatus, and equipment for a flexible DC converter valve power module, which addresses the technical problem that existing insulation testing methods for flexible DC converter valves lack insulation testing capabilities suitable for high-altitude applications.

[0006] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0007] An insulation test method for a flexible DC converter valve power module includes the following steps:

[0008] Obtain the power element to be tested and the test type corresponding to the power element, wherein the test type includes electrical clearance insulation test and creepage distance insulation test;

[0009] The test conditions are determined based on the power element and the test type.

[0010] The power element was subjected to insulation testing using the rising and falling methods according to the test conditions to obtain the withstand voltage.

[0011] The withstand voltage is corrected by a correction factor to obtain the voltage at which the power element operates in a high-altitude environment.

[0012] Preferably, determining the test conditions based on the power element and the test type includes:

[0013] If the power element is a power device of a flexible DC converter valve power module, and the test type is an electrical clearance insulation test, then the test conditions are humidity above 60% and temperature below 5 degrees Celsius.

[0014] If the power element is a power device of a flexible DC converter valve power module, and the test type is a creepage distance insulation test, then the test conditions are humidity of 60% to 70%, temperature below 5 degrees Celsius, and pollution level of Class I or Class II.

[0015] If the power element is at least one flexible DC converter valve power module, and the test type is electrical clearance insulation test, then the test conditions are humidity above 60% and temperature below 5 degrees Celsius.

[0016] The power device is an IGBT, a diode, or a bypass thyristor.

[0017] Preferably, the power element is subjected to insulation testing using the rising method and the rising-falling method according to the test conditions to obtain the withstand voltage, including:

[0018] The power element is subjected to n insulation tests using the rising method to select the first test voltage until the power element is broken down or the insulation surface of the power element is damaged and remains damaged for a certain period of time, thus obtaining a test power element.

[0019] The second test voltage is selected by using the step-up method to perform m effective insulation tests on the power element under the first test, resulting in m second test voltages;

[0020] The withstand voltage is calculated based on m of the second test voltages;

[0021] Wherein, n is a natural number greater than 0, m is a natural number not less than 20, and the effective insulation test is to perform an insulation test on the primary test power element using the selected second test voltage to obtain whether the primary test power element is insulation broken down or the insulation surface of the power element is damaged.

[0022] Preferably, the first test voltage is U n U n =U n-1 +(n-1)ΔU1, when n=1, U0=0, ΔU1 is the voltage added for one insulation test using the rising method.

[0023] Preferably, the second test voltage is U' m , when m=1, U'1=U n When m is greater than 2, U' m =U' m-1 +ΔU2, ΔU2 is B×U' m-1 or -(B×U' m-1 ), B is the percentage coefficient, U' m-1 This is the second test voltage for the (m-1)th test.

[0024] Preferably, the voltage of the power element operating in a high-altitude environment is obtained by correcting the withstand voltage using a correction factor, which includes: obtaining the correction factor based on the altitude environment in which the power element is used, and calculating the voltage of the power element operating in a high-altitude environment using the correction factor and the withstand voltage.

[0025] The present invention also provides an insulation testing device for a flexible DC converter valve power module, including a test data acquisition module, a test condition determination module, an insulation testing module, and a correction module;

[0026] The test data acquisition module is used to acquire the power component to be tested and the test type corresponding to the power component. The test type includes electrical clearance insulation test and creepage distance insulation test.

[0027] The test condition determination module is used to determine test conditions based on the power element and the test type.

[0028] The insulation test module is used to perform insulation tests on the power element according to the test conditions using the rising method and the rising and falling method to obtain the withstand voltage.

[0029] The correction module is used to correct the withstand voltage using a correction coefficient to obtain the voltage at which the power element operates in a high-altitude environment.

[0030] Preferably, the insulation testing module is further configured to use a rising method to select a first test voltage and perform n insulation tests on the power element until the power element is broken down or the insulation surface of the power element is damaged and remains damaged for a certain period of time, thus obtaining a first-test power element; use a rising and falling method to select a second test voltage and perform m effective insulation tests on the first-test power element, thus obtaining m second test voltages; calculate the withstand voltage based on the m second test voltages; wherein, n is a natural number greater than 0, m is a natural number not less than 20, and the effective insulation test is performed by using the selected second test voltage to test the first-test power element until the first-test power element is broken down or the insulation surface of the power element is damaged; the first test voltage is U n U n =U n-1 +(n-1)ΔU1, when n=1, U0=0, ΔU1 is the voltage added during the first insulation test using the rising method; the second test voltage is U' m , when m=1, U'1=U n When m is greater than 2, U' m =U' m-1 +ΔU2, ΔU2 is B×U' m-1 or -(B×U' m-1 ), B is the percentage coefficient, U' m-1 This is the second test voltage for the (m-1)th test.

[0031] Preferably, the test condition determination module is further configured to, based on the power element being a power device of a flexible DC converter valve power module and the test type being an electrical clearance insulation test, specify the test conditions as humidity above 60% and temperature below 5 degrees Celsius; or based on the power element being a power device of a flexible DC converter valve power module and the test type being a creepage distance insulation test, specify the test conditions as humidity 60%–70%, temperature below 5 degrees Celsius, and pollution level I or II; or based on the power element being at least one flexible DC converter valve power module and the test type being an electrical clearance insulation test, specify the test conditions as humidity above 60% and temperature below 5 degrees Celsius; wherein the power device is an IGBT, diode, or bypass thyristor.

[0032] The present invention also provides a terminal device, including a processor and a memory;

[0033] The memory is used to store program code and transmit the program code to the processor;

[0034] The processor is used to execute the insulation test method for the flexible DC converter valve power module described above according to the instructions in the program code.

[0035] As can be seen from the above technical solutions, the embodiments of the present invention have the following advantages: The insulation testing method, apparatus, and equipment for the power module of the flexible DC converter valve include: acquiring the power element to be tested and the test type corresponding to the power element, the test type including electrical clearance insulation test and creepage distance insulation test; determining test conditions according to the power element and the test type; performing insulation testing on the power element using the rising method and the rising and falling method according to the test conditions to obtain the withstand voltage; and correcting the withstand voltage using a correction factor to obtain the voltage at which the power element can operate in high-altitude scenarios. This insulation testing method for the power module of the flexible DC converter valve can perform insulation testing on the power module or the power device of the power module in the flexible DC converter valve to obtain the withstand voltage. Then, a correction factor is used to correct the withstand voltage to obtain the voltage at which the power element can operate in high-altitude scenarios. This voltage can guide the insulation design of the power element used in high-altitude scenarios, solving the technical problem that existing insulation testing methods for flexible DC converter valves lack insulation testing for flexible DC converter valves used at high altitudes. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a flowchart illustrating the steps of the insulation testing method for the power module of the flexible DC converter valve according to an embodiment of the present invention.

[0038] Figure 2 This is a topology diagram of the flexible DC converter valve power module according to an embodiment of the present invention;

[0039] Figure 3 This is a frame diagram of the insulation testing device for the flexible DC converter valve power module according to an embodiment of the present invention. Detailed Implementation

[0040] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0041] This application provides an insulation testing method, apparatus, and equipment for a flexible DC converter valve power module, addressing the technical problem that existing insulation testing methods for flexible DC converter valves lack insulation testing capabilities suitable for high-altitude applications. This insulation testing method, apparatus, and equipment can perform insulation testing not only on the power module of the flexible DC converter valve but also on the power devices within the power module. The insulation tests include DC withstand voltage testing, lightning impulse testing, and switching impulse testing.

[0042] Example 1:

[0043] Figure 1 This is a flowchart illustrating the steps of the insulation testing method for the power module of the flexible DC converter valve according to an embodiment of the present invention. Figure 2 This is a topology diagram of the flexible DC converter valve power module according to an embodiment of the present invention.

[0044] like Figure 1 As shown, this embodiment of the invention provides an insulation testing method for a flexible DC converter valve power module, comprising the following steps:

[0045] S1. Obtain the power component to be tested and the corresponding test type. The test types include electrical clearance insulation test and creepage distance insulation test.

[0046] It should be noted that step S1 mainly involves acquiring the power device to be tested and the test type to provide a basis for subsequent testing. In this embodiment, the power device to be tested can be a power device in the power module of a flexible DC-DC converter valve, or it can be the power module itself. For example... Figure 2 As shown, the power devices include IGBT transistors T1 or T2, diodes D1 or D2, and bypass thyristors SCR in the power module. Due to the limited voltage withstand capability of the power devices, specially customized power devices are required. The external package of the power device should maintain the original design, while the internal chip is replaced with insulating material to ensure the performance and function of the power device.

[0047] S2. Determine the test conditions based on the power components and the test type.

[0048] It should be noted that in step S2, the test conditions for insulation testing of the power element can be determined according to the power element and the test type, or the test conditions for insulation testing of the power element can be determined according to the power element.

[0049] Furthermore, the test conditions are determined based on the power component and the test type, including:

[0050] If the power element is a power device of a flexible DC converter valve power module, and the test type is electrical clearance insulation test, then the test conditions are humidity above 60% and temperature below 5 degrees.

[0051] If the power element is a power device of a flexible DC converter valve power module, and the test type is creepage distance insulation test, then the test conditions are humidity of 60% to 70%, temperature below 5 degrees Celsius, and pollution level of Class I or Class II.

[0052] If the power component is at least one flexible DC converter valve power module, and the test type is electrical clearance insulation test, then the test conditions are humidity above 60% and temperature below 5 degrees Celsius; the power device is an IGBT, diode, or bypass thyristor.

[0053] It should be noted that the pollution level is determined based on the nature and severity of the pollution sources in the substation, which is common knowledge and will not be elaborated upon here. In this embodiment, the insulation testing method for the power modules of the flexible DC converter valve can perform insulation testing on a single power module of the flexible DC converter valve, or it can perform insulation testing on multiple power modules of the flexible DC converter valve. The specific number of power modules tested is determined based on the capability of the test impulse voltage generator. For example... Figure 2 As shown, since the power module needs to consider the energy storage function of DC voltage, impulse voltage cannot be applied. Therefore, the DC capacitor C in the power module needs to be modified. A solution can be adopted that uses the same volume and size as the original capacitor, but replaces it with a core with a smaller capacitance value. In addition, during the insulation test of the power module, the voltage is gradually increased, which will exceed the withstand capacity limit of the DC capacitor C. Therefore, the DC capacitor C in the power module can be replaced with a capacitor with a higher voltage rating than the one used in plain areas.

[0054] In this embodiment, if the power element is a power device of a flexible DC converter valve power module, and the test type is creepage distance insulation test, the surface of the power element must be evenly coated with dirt before the insulation test, and left to dry for at least 6 hours. When the insulation test of the power element requires the test object to reach its tolerance limit, flashover, breakdown discharge, or cooling system breakdown may occur.

[0055] S3. Based on the test conditions, use the rising method and the rising-falling method to perform insulation tests on the power components and obtain the withstand voltage.

[0056] It should be noted that in step S3, the power element can be subjected to insulation tests by the rising method and the rising and falling method in sequence to obtain the test results, which are the withstand voltages of the power element.

[0057] S4. The withstand voltage is corrected using a correction factor to obtain the voltage at which the power components operate in high-altitude environments.

[0058] It should be noted that in step S4, the withstand voltage obtained in step S3 can be corrected by a correction coefficient to obtain the corrected voltage data, which is the withstand voltage of the power element that can work in high-altitude scenarios.

[0059] Furthermore, the withstand voltage is corrected using a correction factor to obtain the voltage at which the power component operates in a high-altitude environment. This includes obtaining the correction factor based on the altitude environment at which the power component is used, and calculating the voltage at which the power component operates in a high-altitude environment using the correction factor and the withstand voltage.

[0060] It should be noted that, according to GB / T 311.1-2012, the correction factor for the insulation withstand level of the power element is obtained based on the altitude at which the power element operates in a high-altitude environment. Then, the product of the correction factor and the withstand voltage is taken as the voltage at which the power element operates in a high-altitude environment.

[0061] This invention provides an insulation testing method for a power module of a flexible DC-DC converter valve. The method includes acquiring the power element under test and the corresponding test type, including electrical clearance insulation testing and creepage distance insulation testing; determining test conditions based on the power element and test type; performing insulation testing on the power element using the rising method and the rising-falling method according to the test conditions to obtain the withstand voltage; and correcting the withstand voltage using a correction factor to obtain the voltage at which the power element operates in high-altitude environments. This insulation testing method for the power module of a flexible DC-DC converter valve enables insulation testing of the power module or power devices within the power module to obtain the withstand voltage. Then, by applying a correction factor to the withstand voltage, the voltage at which the power element can operate in high-altitude environments is obtained. This voltage can guide the insulation design of the power element used in high-altitude environments, solving the technical problem of existing insulation testing methods for flexible DC-DC converter valves lacking insulation testing for use at high altitudes.

[0062] In one embodiment of the present invention, insulation testing of a power element is performed using both the rising and rising / falling methods according to test conditions to obtain the withstand voltage, including:

[0063] The first test voltage is selected using the rising method to perform n insulation tests on the power element until the power element is broken down or the insulation surface of the power element is damaged and remains damaged for a certain period of time, thus obtaining a test power element;

[0064] The second test voltage is selected by using the step-up method to perform m effective insulation tests on the power element under primary test, resulting in m second test voltages;

[0065] The withstand voltage is calculated based on m second test voltages;

[0066] Where n is a natural number greater than 0, m is a natural number not less than 20, and the effective insulation test is to perform an insulation test on the primary test power element using the selected second test voltage to obtain whether the primary test power element is broken down or the insulation surface of the power element is damaged.

[0067] Furthermore, the first test voltage is U n U n =U n-1 +(n-1)ΔU1, when n=1, U0=0, ΔU1 is the voltage added during the first insulation test using the rising method. The second test voltage is U'. m , when m=1, U'1=U n When m is greater than 2, U' m =U' m-1 +ΔU2, ΔU2 is B×U' m-1 or -(B×U' m-1 ), B is the percentage coefficient, U' m-1 This is the second test voltage for the (m-1)th test.

[0068] It should be noted that ΔU1 can be 1kV, m can be 20, and B can be 1% to 6%. First, the insulation test of the power element is performed using the step-up method. The first test voltage starts from 0 and increases by approximately 1kV each time. During each test, the power element is observed for gap discharge, and the duration of this gap discharge is maintained for approximately 2 minutes. If no gap discharge occurs, the voltage is increased further until insulation breakdown (solid insulation breakdown or air breakdown) or leakage tracking occurs on the insulator surface, thus obtaining the first-stage test power element. Then, the step-down method is used to perform the insulation test of the first-stage test power element. The first test voltage U1 is used... n An insulation test is conducted using the second test voltage. If the power element does not experience gap discharge, it is considered to be in an withstand state. The second test voltage U' m The voltage U' in the previous test m-1 Increase ΔU2 based on the existing value; otherwise, decrease ΔU2 by the same amount. In this embodiment, the step-up / step-down method is used to perform insulation tests on the power element. The voltage value of the second experimental voltage should ensure that each insulation test is valid. The step-up / step-down method is used to perform a total of 20 valid tests on the power element to determine the current withstand voltage that the power element can withstand. The withstand voltage refers to the upper limit of voltage that the power element can withstand.

[0069] In an embodiment of the present invention, the withstand voltage is the sum of m effective second test voltages.

[0070] Example 2:

[0071] Figure 3 This is a frame diagram of the insulation testing device for the flexible DC converter valve power module according to an embodiment of the present invention.

[0072] like Figure 3 As shown, this embodiment of the invention also provides an insulation testing device for a flexible DC converter valve power module, including a test data acquisition module 10, a test condition determination module 20, an insulation testing module 30, and a correction module 40;

[0073] The test data acquisition module 10 is used to acquire the power component under test and the test type corresponding to the power component. The test types include electrical clearance insulation test and creepage distance insulation test.

[0074] Test condition determination module 20 is used to determine test conditions based on power components and test type;

[0075] The insulation test module 30 is used to perform insulation tests on power components using the rising method and the rising-falling method according to the test conditions, and to obtain the withstand voltage.

[0076] The correction module 40 is used to correct the withstand voltage using a correction factor to obtain the voltage at which the power element operates in a high-altitude environment.

[0077] In this embodiment, the insulation testing module 30 is further configured to use a rising method to select a first test voltage and perform n insulation tests on the power element until the power element is broken down or the insulation surface of the power element is damaged and remains damaged for a certain period of time, thus obtaining a first-test power element; use a rising and falling method to select a second test voltage and perform m effective insulation tests on the first-test power element, thus obtaining m second test voltages; and calculate the withstand voltage based on the m second test voltages; wherein, n is a natural number greater than 0, m is a natural number not less than 20, and an effective insulation test is performed by using the selected second test voltage to test the first-test power element until the first-test power element is broken down or the insulation surface of the power element is damaged; the first test voltage is U n U n =U n-1 +(n-1)ΔU1, when n=1, U0=0, ΔU1 is the voltage added during the first insulation test using the rising method; the second test voltage is U' m , when m=1, U'1=U n When m is greater than 2, U' m =U' m-1 +ΔU2, ΔU2 is B×U' m-1 or -(B×U' m-1 ), B is the percentage coefficient, U' m-1 This is the second test voltage for the (m-1)th test.

[0078] In this embodiment, the test condition determination module 20 is further configured to determine the test conditions as follows: if the power element is a power device of a flexible DC converter valve power module and the test type is electrical clearance insulation test, the test conditions are humidity above 60% and temperature below 5 degrees Celsius; or if the power element is a power device of a flexible DC converter valve power module and the test type is creepage distance insulation test, the test conditions are humidity between 60% and 70%, temperature below 5 degrees Celsius, and pollution level I or II; or if the power element is at least one flexible DC converter valve power module and the test type is electrical clearance insulation test, the test conditions are humidity above 60% and temperature below 5 degrees Celsius; the power device is an IGBT, diode, or bypass thyristor.

[0079] It should be noted that the modules in the device of Embodiment 2 correspond to the steps in the method of Embodiment 1. The insulation test method of the flexible DC converter valve power module has been described in detail in Embodiment 1, and the content of the modules in the device will not be described in detail in this Embodiment 2.

[0080] Example 3:

[0081] This invention provides a terminal device, including a processor and a memory;

[0082] Memory is used to store program code and transfer the program code to the processor;

[0083] The processor is used to execute the insulation test method of the flexible DC converter valve power module as described above, according to the instructions in the program code.

[0084] It should be noted that the processor is used to execute the steps in the above-described embodiment of an insulation testing method for a flexible DC converter valve power module according to the instructions in the program code. Alternatively, when the processor executes the computer program, it implements the functions of each module / unit in the above-described system / device embodiments.

[0085] For example, a computer program can be divided into one or more modules / units, one or more of which are stored in memory and executed by a processor to complete this application. One or more modules / units can be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program in a terminal device.

[0086] Terminal devices can be computing devices such as desktop computers, laptops, handheld computers, and cloud servers. Terminal devices may include, but are not limited to, processors and memory. Those skilled in the art will understand that this does not constitute a limitation on the terminal device, which may include more or fewer components than illustrated, or combinations of certain components, or different components. For example, a terminal device may also include input / output devices, network access devices, buses, etc.

[0087] The processor referred to can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0088] Memory can be an internal storage unit of a terminal device, such as a hard drive or RAM. Memory can also be an external storage device, such as a plug-in hard drive, SmartMedia Card (SMC), Secure Digital (SD) card, or Flash Card. Furthermore, memory can include both internal and external storage units. Memory is used to store computer programs and other programs and data required by the terminal device. Memory can also be used to temporarily store data that has been output or will be output.

[0089] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0090] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between apparatuses or units through some interfaces, and may be electrical, mechanical, or other forms.

[0091] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0092] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0093] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0094] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of insulation testing of a flexible HVDC converter valve power module, characterized by, The method comprises the following steps: obtaining a power element to be tested and a test type corresponding to the power element, the test type comprising electrical clearance insulation test and creepage distance insulation test; determining a test condition according to the power element and the test type; performing insulation test on the power element according to the test condition by using the up method and the up-down method to obtain a withstand voltage; correcting the withstand voltage by using a correction coefficient to obtain a voltage at which the power element works in a high-altitude scenario; performing insulation test on the power element according to the test condition by using the up method and the up-down method to obtain a withstand voltage comprises: selecting a first test voltage by using the up method to perform n times of insulation test on the power element until the power element is insulation breakdown or the insulation surface of the power element is damaged and maintained for a certain time to obtain a power element for one time test; selecting a second test voltage by using the up-down method to perform m times of effective insulation test on the power element for one time test to obtain m second test voltages; calculating a withstand voltage according to the m second test voltages; Wherein, n is a natural number greater than 0, m is a natural number not less than 20, the effective insulation test is that the insulation of the primary test power element is broken or the insulation surface of the power element is damaged when the insulation of the primary test power element is tested by the selected second test voltage; the second test voltage is U' m ; when m = 1, U' 1 = U n ; when m is greater than 2, U' m = U' m-1 + ΔU 2, ΔU 2 is BxU' m-1 or - (BxU' m-1 ), B is a percentage coefficient, and U' m-1 is the (m-1)th second test voltage.

2. The method of insulation testing of a flexible HVDC valve power module according to claim 1, characterized in that, determining a test condition according to the power element and the test type comprises: if the power element is a power device of a flexible direct-current converter valve power module and the test type is electrical clearance insulation test, the test condition is humidity of 60% or above and temperature of 5 degrees or below; if the power element is a power device of a flexible direct-current converter valve power module and the test type is creepage distance insulation test, the test condition is humidity of 60% to 70%, temperature of 5 degrees or below and grade I or grade II pollution level; if the power element is at least one flexible direct-current converter valve power module and the test type is electrical clearance insulation test, the test condition is humidity of 60% or above and temperature of 5 degrees or below. The power device is an IGBT tube, a diode or a bypass thyristor.

3. The method of claim 1, wherein, The first test voltage is U n , U n =U n-1 + (n-1) ΔU1, when n=1, U0=0, and ΔU1 is the voltage increased by one insulation test using the rising method.

4. The method of claim 1, wherein, The correction coefficient is obtained according to the use altitude environment of the power element, and the voltage at which the power element works in a high-altitude scenario is the correction coefficient and the calculated withstand voltage.

5. An insulation testing device for a flexible HVDC converter valve power module, characterized in that, The method comprises a test data acquisition module, a test condition determination module, an insulation test module and a correction module. The test data acquisition module is used to obtain a power element to be tested and a test type corresponding to the power element, the test type comprising electrical clearance insulation test and creepage distance insulation test. The test condition determination module is used to determine a test condition according to the power element and the test type. The insulation test module is used to perform insulation test on the power element according to the test condition by using the up method and the up-down method to obtain a withstand voltage. The correction module is used to correct the withstand voltage by using a correction coefficient to obtain a voltage at which the power element works in a high-altitude scenario. The insulation testing module is further configured to use a rising method to select a first test voltage and perform n insulation tests on the power element until the power element is broken down or the insulation surface of the power element is damaged and remains damaged for a certain period of time, thus obtaining a first-test power element; use a rising and falling method to select a second test voltage and perform m effective insulation tests on the first-test power element, thus obtaining m second test voltages; calculate the withstand voltage based on the m second test voltages; where n is a natural number greater than 0, m is a natural number not less than 20, and the effective insulation test is performed on the first-test power element using the selected second test voltage until the first-test power element is broken down or the insulation surface of the power element is damaged; the first test voltage is U n U n =U n-1 +(n-1)ΔU1, when n=1, U0=0, ΔU1 is the voltage added during the first insulation test using the rising method; the second test voltage is U' m , when m=1, U'1=U n When m is greater than 2, U' m =U' m-1 +ΔU2, ΔU2 is B×U' m-1 or - (B×U' m-1 B is the percentage coefficient, U' m-1 This is the second test voltage for the (m-1)th test.

6. The insulation test device of a flexible HVDC valve power module according to claim 5, characterized in that, The test condition determination module is further configured to determine, according to the power element being a power device of the flexible DC converter valve power module and the test type being an electrical clearance insulation test, the test condition to be humidity of 60% or above and temperature of 5 degrees or below; or according to the power element being a power device of the flexible DC converter valve power module and the test type being a creepage distance insulation test, the test condition to be humidity of 60%-70%, temperature of 5 degrees or below and a level I or level II pollution level; or according to the power element being at least one flexible DC converter valve power module and the test type being an electrical clearance insulation test, the test condition to be humidity of 60% or above and temperature of 5 degrees or below; and the power device is an IGBT tube, a diode or a bypass thyristor.

7. A terminal device, characterized by comprising: The device comprises a processor and a memory; The memory is configured to store program code and transmit the program code to the processor; The processor is configured to execute the insulation test method of the flexible DC converter valve power module according to instructions in the program code.

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