Calculation Method and Device for Cumulative Damage of DC Contactor

Abstract

The present invention discloses a calculation method and device for the cumulative damage of a DC contactor. Among them, the method includes: performing an opening test on the output contactor under a first test condition to obtain the single-contact erosion amount of the output contactor; performing an opening test on the output contactor under a second test condition to obtain a binary function mathematical model; using the binary function mathematical model to calculate the single damage of the output contactor according to the break voltage, the breaking current, and the single-contact erosion amount of the output contactor during each opening test, and accumulating a plurality of the single damages to calculate the cumulative damage of the output contactor. The present invention solves the technical problem in the prior art that it is difficult to achieve online calculation of the cumulative damage of the output contactor of a DC charging pile.

Description

Technical Field

[0001] The present invention relates to the field of electric vehicle charging piles, and more particularly, to a method and device for calculating the cumulative damage of a DC contactor. Background Art

[0002] In recent years, the number of electric vehicles has been growing rapidly globally. The related supporting facilities mainly composed of charging piles have been continuously developed and improved. The number of charging piles in cities is increasing day by day, which puts forward higher requirements for the reliability and safety of electric vehicle charging piles. The fault statistics data of DC charging piles in the provincial vehicle networking application platform shows that the failure rate of the output contactor ranks second among all components of the DC charging pile (the first is the charging module, a power electronic device). The on-site maintenance results of DC charging piles show that the main reason for the failure of the output contactor is the interruption of large current.

[0003] The output contactor of a DC charging pile belongs to a DC contactor. At present, the research on DC contactors mainly focuses on the prediction of electrical life, emphasizing the erosion effect of DC arcs on the contacts of DC contactors. The state parameters selected to characterize the cumulative damage of DC contactors are mostly parameters such as cumulative arcing energy, release time, and release voltage, which need to be collected under specific equipment or high sampling frequencies and are difficult to apply on-site and even more difficult to achieve online monitoring.

[0004] In view of the above problems, no effective solution has been proposed yet. Summary of the Invention

[0005] Embodiments of the present invention provide a method and device for calculating the cumulative damage of a DC contactor, so as to at least solve the technical problem in the prior art that it is difficult to calculate the cumulative damage of the output contactor of a DC charging pile online.

[0006] According to one aspect of the embodiments of the present invention, a method for calculating the cumulative damage of a DC contactor, which is the output contactor of a DC charging pile, is provided, including: performing an opening test on the output contactor under a first test condition to obtain the single erosion amount of the contacts of the output contactor, where the breaking voltage and breaking current are rated under the first test condition, and the end point of the opening test is the electrical life end point of the output contactor; performing an opening test on the output contactor under a second test condition to obtain a binary function mathematical model, where the breaking voltage and breaking current are different under the second test condition, and the binary function mathematical model is used to reflect the binary function relationship between the electrical life of the output contactor and the breaking voltage and the breaking current; using the binary function mathematical model to calculate the single damage of the output contactor according to the breaking voltage, the breaking current, and the single erosion amount of the contacts of the output contactor during each opening test, and accumulating multiple single damages to calculate the cumulative damage of the output contactor.

[0007] Optionally, an opening and closing test is performed on the above output contactor under the first test condition to obtain the single - time erosion amount of the contact of the above output contactor, including: performing multiple above opening and closing tests on the above output contactor under the above first test condition, wherein the above opening and closing test is used to measure the mass of the contact of the above output contactor by using a precision balance, and the single - time erosion amount of the contact is characterized by the mass of the contact; recording the change amount of the mass of the contact after every N times of the above opening and closing tests; if the above change amount conforms to a normal distribution and the confidence interval of a predetermined percentage is near the confidence mean value, determining that the single - time erosion amount of the contact of the above output contactor caused by the DC arc of the above opening and closing test is a predetermined erosion amount.

[0008] Optionally, an opening and closing test is performed on the above output contactor under the second test condition to obtain a binary function mathematical model, including: performing an opening and closing test on the above output contactor under the above second test condition, wherein the time of a single above opening and closing test is fixed, until the above output contactor loses the breaking ability, then determining that the above output contactor reaches the end of the electrical life, recording the number of voltage rising edges as the electrical life of the above output contactor; fitting the above electrical life, the above contact voltage and the above breaking current through a mathematical fitting tool to obtain the above binary function mathematical model.

[0009] Optionally, before performing the opening and closing test on the above output contactor under the above second test condition, the above method further includes: setting the breaking test circuit of the above output contactor and the above second test condition, wherein the above breaking test circuit includes: any one or more loads, a control unit, a voltage and current acquisition system, and the above second test condition includes: setting multiple groups of the above contact voltage and the above breaking current.

[0010] According to another aspect of the embodiments of the present invention, there is also provided a calculation device for the cumulative damage of a DC contactor. The DC contactor is an output contactor of a DC charging pile, and includes: a first test unit for performing a breaking test on the output contactor under a first test condition to obtain the single-contact erosion amount of the contacts of the output contactor, wherein the breaking voltage and the breaking current under the first test condition are rated, and the end point of the breaking test is the electrical life end point of the output contactor; a second test unit for performing a breaking test on the output contactor under a second test condition to obtain a binary function mathematical model, wherein the breaking voltage and the breaking current under the second test condition are different, and the binary function mathematical model is used to reflect the binary function relationship between the electrical life of the output contactor and the breaking voltage and the breaking current; a calculation unit for using the binary function mathematical model to calculate the single damage of the output contactor according to the breaking voltage, the breaking current and the single-contact erosion amount of the output contactor during each breaking test, and accumulating multiple single damages to calculate the cumulative damage of the output contactor.

[0011] Optionally, the first test unit includes: a first test subunit for performing multiple breaking tests on the output contactor under the first test condition, wherein the breaking test is used to measure the contact mass of the output contactor by using a precision balance, and the contact mass is used to characterize the single-contact erosion amount; a recording unit for recording the change amount of the contact mass after every N breaking tests; a determining unit for determining that the single-contact erosion amount of the contacts of the output contactor caused by the DC arc during the breaking test is a predetermined erosion amount if the change amount conforms to a normal distribution and the confidence interval of a predetermined percentage is near the confidence mean value.

[0012] Optionally, the second test unit includes: a second test subunit for performing a breaking test on the output contactor under the second test condition, wherein the time of a single breaking test is fixed, and when the output contactor loses the breaking ability, it is determined that the output contactor reaches the electrical life end point, and the number of voltage rising edges is recorded as the electrical life of the output contactor; a fitting unit for fitting the electrical life with the breaking voltage and the breaking current through a mathematical fitting tool to obtain the binary function mathematical model.

[0013] Optionally, the device further includes: a setting unit for setting the breaking test circuit of the output contactor and the second test condition, wherein the breaking test circuit includes: any one or more loads, a control unit, and a voltage and current acquisition system, and the second test condition includes: setting multiple groups of the breaking voltage and the breaking current.

[0014] According to another aspect of the embodiments of the present invention, there is also provided a computer-readable storage medium storing multiple instructions adapted to be loaded and executed by a processor to perform the calculation method for the cumulative damage of any of the above-mentioned DC contactors.

[0015] According to another aspect of the embodiments of the present invention, there is also provided an electronic device including a memory and a processor, where a computer program is stored in the memory, and the processor is configured to run the computer program to execute the calculation method for the cumulative damage of any of the above-mentioned DC contactors.

[0016] In the embodiments of the present invention, an online calculation method for the cumulative damage of the output contactor of a DC charging pile is adopted. By performing a breaking test on the output contactor under a first test condition, the single erosion amount of the contact of the output contactor is obtained. Among them, the breaking voltage and breaking current rating under the first test condition, and the end point of the breaking test is the electrical life end point of the output contactor; a binary function mathematical model is obtained by performing a breaking test on the output contactor under a second test condition, where the breaking voltage and breaking current under the second test condition are different, and the binary function mathematical model is used to reflect the binary function relationship between the electrical life of the output contactor and the breaking voltage and the breaking current; using the binary function mathematical model, according to the breaking voltage, the breaking current and the single erosion amount of the contact of the output contactor during each breaking test, the single damage of the output contactor is calculated, and the multiple single damages are accumulated to calculate the cumulative damage of the output contactor, achieving the purpose of online calculation of the cumulative damage of the output contactor of a DC charging pile, thereby realizing the technical effect of improving the reliability and safety of an electric vehicle charging pile, and further solving the technical problem that it is difficult to realize the online calculation of the cumulative damage of the output contactor of a DC charging pile in the prior art. Description of the Drawings

[0017] The drawings described herein are used to provide a further understanding of the present invention, and constitute a part of this application. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0018] Figure 1 is a flowchart of a calculation method for the cumulative damage of a DC contactor according to an embodiment of the present invention;

[0019] Figure 2 is a flowchart of an optional calculation method for the cumulative damage of a DC contactor according to an embodiment of the present invention;

[0020] Figure 3 is a schematic structural diagram of a calculation device for the cumulative damage of a DC contactor according to an embodiment of the present invention. Detailed implementation manners

[0021] In order to enable those skilled in the art of the present technology to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with 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. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0022] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0023] The current research does not consider the information feedback of on-site maintenance results, nor does it consider the influence of high break voltage and large breaking current on the cumulative damage of the DC charging pile output contactor. Therefore, the purpose of the embodiments of the present invention is at least to provide a method for evaluating the cumulative damage of the DC charging pile output contactor based on the break voltage and breaking current, and to solve the problem that it is difficult to realize the online evaluation of the health state of the output contactor of the existing DC charging piles in the prior art.

[0024] Embodiment 1

[0025] According to the embodiments of the present invention, an embodiment of a calculation method for the cumulative damage of a DC contactor is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0026] Figure 1 is a flowchart of a calculation method for the cumulative damage of a DC contactor according to the embodiments of the present invention. As Figure 1 shown, the method includes the following steps:

[0027] Step S102, perform an opening test on the above output contactor under the first test condition to obtain the single - erosion amount of the contact of the above output contactor. Among them, the breaking voltage and breaking current under the above first test condition are rated, and the end point of the above opening test is the end point of the electrical life of the above output contactor;

[0028] Step S104, under the second test condition, perform an opening test on the above output contactor to obtain a binary - function mathematical model. Among them, the breaking voltage and breaking current under the above second test condition are different, and the binary - function mathematical model is used to reflect the binary - function relationship between the electrical life of the above output contactor and the above breaking voltage and the above breaking current;

[0029] Step S106, use the above binary - function mathematical model to calculate the single - damage of the above output contactor according to the above breaking voltage, the above breaking current and the single - erosion amount of the contact during each opening test of the above output contactor, and accumulate multiple above single - damages to calculate the cumulative damage of the above output contactor.

[0030] In the embodiment of the present application, the DC contactor is the output contactor of a DC charging pile. By performing an opening test on the output contactor under rated voltage and current conditions until the end point of its electrical life, the distribution characteristics of the single - erosion amount of the contact are obtained; by performing an opening test on the output contactor under different breaking voltages and breaking currents until the end point of its electrical life, a binary - function mathematical model of the electrical life L (times) of the output contactor with respect to the breaking voltage U and the breaking current I is obtained, and the single - damage 1 / L (dimensionless: 1 / time) under this breaking voltage and breaking current is obtained. In addition, by recording the breaking voltage and breaking current during each breaking of the output contactor, the single - damage is calculated, and the single - damages are accumulated to obtain the cumulative damage during the life cycle of the output contactor.

[0031] It should be noted that the breaking voltage and breaking current collected in the embodiment of the present invention are very easy to collect. The TCU unit of the DC charging pile can perform the collection and calculation, and can realize the online evaluation of the cumulative damage of the output contactor.

[0032] The method for evaluating the cumulative damage of the DC charging - pile output contactor based on the breaking voltage and breaking current provided by the present invention abstracts the theoretical cumulative - damage evaluation problem into a multivariate - function fitting problem in mathematics. The single - opening breaking voltage and breaking current are regarded as independent variables, and the single - damage is regarded as the dependent variable. Then, a function relationship between the independent variable and the dependent variable is fitted by using a multivariate - function fitting tool, and the single - damages are accumulated to obtain the cumulative damage. In this way, for an output contactor whose cumulative - damage state is unknown, only by inputting its corresponding independent variables, the cumulative damage of the output contactor can be obtained. Also, because the independent variables are relatively easy to measure, the method for evaluating the cumulative damage of the DC charging - pile output contactor proposed by the present invention has the advantages of fast operation speed and high reliability.

[0033] In an embodiment of the present invention, by adopting a method of online calculating the cumulative damage of the output contactor of a DC charging pile, the purpose of online calculating the cumulative damage of the output contactor of the DC charging pile can be achieved, thereby realizing the technical effect of improving the reliability and safety of an electric vehicle charging pile, and further solving the technical problem in the prior art that it is difficult to realize online calculation of the cumulative damage of the output contactor of the DC charging pile.

[0034] As an alternative embodiment, Figure 2 is a flowchart of an alternative method for calculating the cumulative damage of a DC contactor according to an embodiment of the present invention. As shown in Figure 2 shown, under a first test condition, an opening and closing test is performed on the above output contactor to obtain the single - time erosion amount of the contact of the above output contactor, including:

[0035] Step S202, under the above first test condition, perform multiple above opening and closing tests on the above output contactor. Among them, the above opening and closing test is used to measure the mass of the contact of the above output contactor by using a precision balance, and the single - time erosion amount of the contact is characterized by the mass of the contact;

[0036] Step S204, record the change amount of the mass of the contact after every N times of the above opening and closing tests;

[0037] Step S206, if the above change amount conforms to a normal distribution and the confidence interval of a predetermined percentage is near the confidence mean value, determine that the single - time erosion amount of the contact of the above output contactor caused by the DC arc of the above opening and closing test is a predetermined erosion amount.

[0038] As an alternative embodiment, the output contactor is subjected to an opening and closing test under rated voltage and current conditions until the end of the electrical life to obtain the distribution characteristics of the single - time erosion amount of the contact. For example, taking the output contactor of model EVQ100 as an example to illustrate the specific implementation method, it specifically includes the following steps: The output contactor is subjected to an opening and closing test under rated voltage and current conditions. The rated voltage is 12 - 1000V. For example, 750V can be selected, and the rated current is 100A. Every 80 times of opening and closing tests are performed, and the mass of the contact of the output contactor is measured by using a precision balance, and the single - time erosion amount of the contact is characterized by the mass of the contact. By recording the change amount Δm of the mass of the contact after every 80 times of opening and closing tests, the conclusion is obtained that the change amount Δm of the mass of the contact after every 80 times of opening and closing tests conforms to a normal distribution and the 95% confidence interval is near the mean value, and the erosion of the single - time DC arc on the output contactor can be considered as a predetermined erosion amount, that is, a fixed value.

[0039] In addition, in the embodiments of the present application, by recording that the electrical life of the output contactor under rated voltage and current conditions is 100,000 times, and recording the change amount Δm of the contact quality of the output contactor after the 1st - 80th and 99,921st - 100,000th opening tests, the above conclusion can be determined to be correct by verifying that there is almost no difference between the two.

[0040] As an optional embodiment, before performing the opening test on the output contactor under the above second test conditions, the method further includes: setting the breaking test circuit of the output contactor and the above second test conditions, wherein the breaking test circuit includes: any one or more loads, a control unit, and a voltage and current acquisition system, and the second test conditions include: setting multiple groups of the break voltage and the breaking current.

[0041] In the embodiments of the present application, by setting the output contactor breaking test circuit, including loads, a control unit, a voltage and current acquisition system, etc.; and setting multiple groups of break voltages and breaking current levels; among them, a pure resistive load box is used as the load to avoid the influence of inductance and capacitance on the opening speed of the output contactor; the control unit uses STM32, the opening period is 1 s, and the opening moment within the opening period is 0.5 s; any suitable DAQ acquisition card is used for the voltage and current acquisition system. Optionally, 20 groups of break voltages and breaking current levels are preset, U = 450 V, I = 5 A, 30 A, 80 A, 120 A, 150 A; U = 550 V, I = 5 A, 30 A, 80 A, 120 A, 150 A; U = 650 V, I = 5 A, 30 A, 80 A, 120 A, 150 A; U = 750 V, I = 5 A, 30 A, 80 A, 120 A, 150 A. When setting 20 groups of break voltages and breaking current levels, the rated voltage and current of the output contactor and the actual operating conditions of the DC charging pile are considered.

[0042] As an optional embodiment, obtaining the binary function mathematical model by performing the opening test on the output contactor under the second test conditions includes:

[0043] Step S302, performing the opening test on the output contactor under the above second test conditions, wherein the time of each single opening test is fixed, until the output contactor loses the breaking ability, then it is determined that the output contactor reaches the end of its electrical life, and the number of voltage rising edges is recorded as the electrical life of the output contactor;

[0044] Step S304, fitting the electrical life with the break voltage and the breaking current through a mathematical fitting tool to obtain the above binary function mathematical model.

[0045] Optionally, the single opening time of the opening test is fixed (the control period is fixed), for example, fixed at 1 s, and the opening moment within the opening period is 0.5 s. Until the output contactor reaches the end of the electrical life of 100,000 times, the sampling frequency of the designed voltage acquisition card is 1 kHz, and the number of rising edges of the voltage waveform is recorded as the actual electrical life L of the output contactor.

[0046] By repeatedly performing opening tests on the output contactor at different contact voltage and breaking current levels until the output contactor loses its breaking ability, it can be considered that the end of the electrical life is reached, and the number of voltage rising edges is recorded as the electrical life L of the output contactor; through a mathematical fitting tool, a binary function mathematical model of the electrical life L (number of times) of the output contactor with respect to the contact voltage U and breaking current I is obtained. According to the above-mentioned single erosion amount of the contact, the single damage 1 / L (dimensionless: 1 / time) at this contact voltage and breaking current can be obtained; through a mathematical fitting tool, a binary function mathematical model of the electrical life L (number of times) of the output contactor with respect to the contact voltage U and breaking current I is obtained. According to the single erosion amount of the contact, the single damage 1 / L (dimensionless: 1 / time) at this contact voltage and breaking current can be obtained. Fitting the obtained electrical life L, contact voltage U, and breaking current I data by mathematical methods, also known as curve fitting, is a way of representing existing data by substituting it into a mathematical formula. For the several discrete data obtained in the above steps, according to these data, by using the least squares fitting, polynomial fitting, or custom function fitting method, a continuous function or surface or a denser discrete equation is obtained on MATLAB to obtain the model of the electrical life L with respect to the contact voltage U and breaking current I.

[0047] In the above optional embodiment, by recording the contact voltage and breaking current at each breaking of the output contactor, calculating the single damage, and accumulating the single damage, the cumulative damage during the life cycle of the output contactor can be obtained. Specifically, it includes the following steps: Step 31: Record the contact voltage and breaking current at each breaking of the output contactor and calculate the single damage; accumulating the single damage under different contact voltages and breaking currents can obtain the cumulative damage, and the cumulative damage characterizes the current health state of the contactor. When the cumulative damage is close to 1, it is considered that the contactor is approaching failure.

[0048] Embodiment 2

[0049] According to an embodiment of the present invention, there is also provided an apparatus embodiment for implementing the calculation method of the cumulative damage of the above-mentioned DC contactor. The DC contactor is the output contactor of a DC charging pile. Figure 3 It is a schematic structural diagram of a calculation device for the cumulative damage of a DC contactor according to an embodiment of the present invention, as Figure 3As shown, the calculation device for the cumulative damage of the above DC contactor includes: a first test unit 300, a second test unit 302, and a calculation unit 304, where:

[0050] The first test unit 300 is used to perform a breaking test on the above output contactor under the first test condition to obtain the single erosion amount of the contact of the above output contactor. Among them, the breaking voltage and breaking current under the above first test condition are rated, and the end point of the above breaking test is the electrical life end point of the above output contactor; the second test unit 302 is used to perform a breaking test on the above output contactor under the second test condition to obtain a binary function mathematical model. Among them, the breaking voltage and breaking current under the above second test condition are different, and the binary function mathematical model is used to reflect the binary function relationship between the electrical life of the above output contactor and the above breaking voltage and the above breaking current; the calculation unit 304 is used to calculate the single damage of the above output contactor by using the above binary function mathematical model according to the above breaking voltage, the above breaking current, and the single erosion amount of the contact during each breaking test of the above output contactor, and accumulate multiple above single damages to calculate the cumulative damage of the above output contactor.

[0051] As an optional embodiment, the above first test unit includes: a first test subunit, which is used to perform multiple above breaking tests on the above output contactor under the above first test condition. Among them, the above breaking test is used to measure the contact mass of the above output contactor by using a precision balance, and the above contact mass is used to characterize the single erosion amount of the contact; a recording unit, which is used to record the change amount of the above contact mass after every N above breaking tests; a determination unit, which is used to determine that the single erosion amount of the contact of the above output contactor by the DC arc of the above breaking test is a predetermined erosion amount if the above change amount conforms to a normal distribution and the confidence interval of a predetermined percentage is near the confidence average value.

[0052] As an optional embodiment, the above second test unit includes: a second test subunit, which is used to perform a breaking test on the above output contactor under the above second test condition. Among them, the time of a single above breaking test is fixed until the above output contactor loses the breaking ability, then it is determined that the above output contactor reaches the electrical life end point, and the number of voltage rising edges is recorded as the electrical life of the above output contactor; a fitting unit, which is used to fit the above electrical life with the above breaking voltage and the above breaking current by using a mathematical fitting tool to obtain the above binary function mathematical model.

[0053] As an alternative embodiment, the above device further includes: a setting unit configured to set the breaking test circuit of the above output contactor and the above second test condition, wherein the breaking test circuit includes: any one or more loads, a control unit, and a voltage and current acquisition system, and the above second test condition includes: setting multiple groups of the above contact voltage and the above breaking current.

[0054] It should be noted that the above-mentioned various modules can be implemented by software or hardware. For example, for the latter, it can be implemented in the following manner: the above-mentioned various modules can be located in the same processor; or, the above-mentioned various modules are located in different processors in any combination.

[0055] It should be noted here that the above-mentioned first test unit 300, second test unit 302, and calculation unit 304 correspond to steps S102 to S106 in Embodiment 1. The examples and application scenarios implemented by the above modules and the corresponding steps are the same, but are not limited to the content disclosed in the above Embodiment 1. It should be noted that the above modules can run in a computer terminal as part of the device.

[0056] It should be noted that the optional or preferred implementation manners of this embodiment can refer to the relevant descriptions in Embodiment 1, and will not be repeated here.

[0057] The above-mentioned calculation device for the cumulative damage of the DC contactor may further include a processor and a memory. The above-mentioned first test unit 300, second test unit 302, calculation unit 304, etc. are all stored in the memory as program units, and the functions are implemented by the processor executing the above program units stored in the memory.

[0058] The processor contains a kernel, and the kernel retrieves the corresponding program units from the memory. One or more kernels can be set. The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM), and / or non-volatile memory in the form of, for example, read-only memory (ROM) or flash memory (flash RAM). The memory includes at least one storage chip.

[0059] According to an embodiment of the present application, an embodiment of a computer-readable storage medium is further provided. Optionally, in this embodiment, the above computer-readable storage medium stores a program, wherein when the above program runs, it controls the device where the above computer-readable storage medium is located to execute any one of the above methods for calculating the cumulative damage of the DC contactor.

[0060] Optionally, in this embodiment, the above computer-readable storage medium may be located in any one of the computer terminals in the computer terminal group in the computer network, or in any one of the mobile terminals in the mobile terminal group. The above computer-readable storage medium includes a stored program.

[0061] Optionally, when the program runs, control the device where the computer-readable storage medium is located to perform the following functions: perform a make-break test on the above output contactor under the first test condition to obtain the single contact erosion amount of the above output contactor, where the breaking voltage and breaking current under the above first test condition are rated, and the end point of the above make-break test is the electrical life end point of the above output contactor; perform a make-break test on the above output contactor under the second test condition to obtain a binary function mathematical model, where the breaking voltage and breaking current under the above second test condition are different, and the above binary function mathematical model is used to reflect the binary function relationship between the electrical life of the above output contactor and the above breaking voltage and the above breaking current; use the above binary function mathematical model to calculate the single damage of the above output contactor according to the above breaking voltage, the above breaking current, and the single contact erosion amount of the contactor during each make-break test, and accumulate multiple above single damages to calculate the cumulative damage of the above output contactor.

[0062] Optionally, when the program runs, control the device where the computer-readable storage medium is located to perform the following functions: perform multiple above make-break tests on the above output contactor under the above first test condition, where the above make-break test is used to measure the contact mass of the above output contactor using a precision balance, and use the above contact mass to characterize the single contact erosion amount; record the change amount of the above contact mass after every N above make-break tests; if the above change amount conforms to a normal distribution and the confidence interval of a predetermined percentage is near the confidence mean value, then determine that the single contact erosion amount of the DC arc of the above make-break test on the above output contactor is a predetermined erosion amount.

[0063] Optionally, when the program runs, control the device where the computer-readable storage medium is located to perform the following functions: perform a make-break test on the above output contactor under the above second test condition, where the time of a single above make-break test is fixed until the above output contactor loses the breaking ability, then determine that the above output contactor reaches the electrical life end point, and record the number of voltage rising edges as the electrical life of the above output contactor; fit the above electrical life with the above breaking voltage and the above breaking current through a mathematical fitting tool to obtain the above binary function mathematical model.

[0064] Optionally, when the program is running, control the device where the computer-readable storage medium is located to perform the following functions: set the breaking test circuit of the above output contactor and the above second test condition, where the breaking test circuit includes: any one or more loads, a control unit, and a voltage and current acquisition system, and the second test condition includes: set multiple groups of the above contact voltage and the above breaking current.

[0065] According to an embodiment of the present application, an embodiment of a processor is further provided. Optionally, in this embodiment, the above processor is used to run a program, where when the above program runs, it executes the above calculation method for the cumulative damage of any DC contactor.

[0066] According to an embodiment of the present application, an embodiment of an electronic device is further provided, including a memory and a processor, where a computer program is stored in the memory, and the processor is configured to run the computer program to execute the above calculation method for the cumulative damage of any DC contactor.

[0067] According to an embodiment of the present application, an embodiment of a computer program product is further provided, which is suitable for executing a program initialized with the steps of the above calculation method for the cumulative damage of any DC contactor when executed on a data processing device.

[0068] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages and disadvantages of the embodiments.

[0069] In the above embodiments of the present invention, the descriptions of the respective embodiments have their own emphases. For parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0070] In several embodiments provided by the present application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only illustrative. For example, the division of the above units can be a logical function division. In actual implementation, there can be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point, the couplings or direct couplings or communication connections shown or discussed with each other can be through some interfaces, and the indirect couplings or communication connections of units or modules can be in electrical or other forms.

[0071] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they can be located in one place, or they can be distributed to multiple units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0072] In addition, in each embodiment of the present invention, the functional units can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

[0073] If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an 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. The computer software product is stored in a computer-readable storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The foregoing computer-readable storage medium includes: various media such as USB flash drives, read-only memories (ROMs), random access memories (RAMs), mobile hard disks, magnetic disks, or optical discs that can store program codes.

[0074] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A calculation method for the cumulative damage of a DC contactor, characterized in that, the DC contactor is the output contactor of a DC charging pile, and includes: conducting a breaking test on the output contactor under a first test condition to obtain the single - erosion amount of the contacts of the output contactor, wherein the breaking voltage and the breaking current under the first test condition are rated, and the end point of the breaking test is the end point of the electrical life of the output contactor; conducting a breaking test on the output contactor under a second test condition to obtain a binary - function mathematical model, wherein the breaking voltage and the breaking current under the second test condition are different, and the binary - function mathematical model is used to reflect the binary - function relationship between the electrical life of the output contactor and the breaking voltage and the breaking current; using the binary - function mathematical model to calculate the single - damage of the output contactor according to the breaking voltage, the breaking current and the single - erosion amount of the contacts during each breaking test of the output contactor, and accumulating multiple single - damages to calculate the cumulative damage of the output contactor; wherein, conducting a breaking test on the output contactor under the first test condition to obtain the single - erosion amount of the contacts of the output contactor includes: conducting multiple breaking tests on the output contactor under the first test condition, wherein the breaking test is used to measure the mass of the contacts of the output contactor by using a precision balance, and using the mass of the contacts to represent the single - erosion amount of the contacts; recording the change amount of the mass of the contacts after every N times of the breaking tests; if the change amount conforms to a normal distribution and the confidence interval of a predetermined percentage is near the confidence mean value, then determining that the single - erosion amount of the contacts of the output contactor caused by the DC arc of the breaking test is a predetermined erosion amount.

2. The calculation method according to claim 1, characterized in that, conducting a breaking test on the output contactor under the second test condition to obtain a binary - function mathematical model includes: conducting a breaking test on the output contactor under the second test condition, wherein the time of a single breaking test is fixed, until the output contactor loses the breaking ability, then determining that the output contactor reaches the end point of the electrical life, and recording the number of voltage rising edges as the electrical life of the output contactor; fitting the electrical life, the breaking voltage and the breaking current through a mathematical fitting tool to obtain the binary - function mathematical model.

3. The calculation method according to claim 1, characterized in that, before conducting a breaking test on the output contactor under the second test condition, the method further includes: setting the breaking - test circuit of the output contactor and the second test condition, wherein the breaking - test circuit includes: any one or more loads, a control unit, a voltage - current acquisition system, and the second test condition includes: setting multiple groups of the breaking voltage and the breaking current.

4. A calculation device for the cumulative damage of a DC contactor, characterized in that, the DC contactor is the output contactor of a DC charging pile, and includes: A first test unit for performing an opening test on the output contactor under a first test condition to obtain the single erosion amount of the contact of the output contactor, wherein the breaking voltage and breaking current under the first test condition are rated, and the end point of the opening test is the end point of the electrical life of the output contactor; A second test unit for performing an opening test on the output contactor under a second test condition to obtain a binary function mathematical model, wherein the breaking voltage and breaking current under the second test condition are different, and the binary function mathematical model is used to reflect the binary function relationship between the electrical life of the output contactor and the breaking voltage and the breaking current; A calculation unit for using the binary function mathematical model to calculate the single damage of the output contactor according to the breaking voltage, the breaking current and the single erosion amount of the contact of the output contactor during each opening test, and accumulating a plurality of the single damages to calculate the cumulative damage of the output contactor; Wherein, the first test unit includes: a first test subunit for performing a plurality of the opening tests on the output contactor under the first test condition, wherein the opening test is used to measure the contact mass of the output contactor by using a precision balance, and the contact mass is used to characterize the single erosion amount of the contact; a recording unit for recording the change amount of the contact mass after every N times of the opening tests; a determining unit for determining that the single erosion amount of the contact of the output contactor by the DC arc of the opening test is a predetermined erosion amount if the change amount conforms to a normal distribution and the confidence interval of a predetermined percentage is near the confidence mean value.

5. The calculation device according to claim 4, wherein, the second test unit includes: a second test subunit for performing an opening test on the output contactor under the second test condition, wherein the time of a single opening test is fixed, and when the output contactor loses the breaking ability, it is determined that the output contactor reaches the end point of the electrical life, and the number of voltage rising edges is recorded as the electrical life of the output contactor; a fitting unit for fitting the electrical life, the breaking voltage and the breaking current by using a mathematical fitting tool to obtain the binary function mathematical model.

6. The calculation device according to claim 4, wherein, the device further includes: a setting unit for setting the breaking test circuit of the output contactor and the second test condition, wherein the breaking test circuit includes: any one or more loads, a control unit, a voltage and current acquisition system, and the second test condition includes: setting multiple groups of the breaking voltage and the breaking current.

7. A computer-readable storage medium, wherein, the computer-readable storage medium stores multiple instructions, and the instructions are suitable for being loaded and executed by a processor to execute the calculation method of the cumulative damage of the DC contactor according to any one of claims 1 to 3.

8. An electronic device, including a memory and a processor, wherein, A computer program is stored in the memory, and the processor is configured to run the computer program to execute the calculation method of the cumulative damage of the DC contactor according to any one of claims 1 to 3.

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