Method and device for testing electrical endurance of alternating current contactor

Abstract

The invention relates to an electrical life test method and device for an AC contactor, and the method comprises the steps: respectively regulating and controlling a current source loop and a voltage source loop according to the use type of the AC contactor, enabling the current source loop to output a target current to the AC contactor, and enabling the voltage source loop to output a target voltage to the AC contactor; configuring test parameters of the current electrical life test; starting a vibration table fixedly connected with the alternating current contactor; according to the test parameters, executing the following cycle control until a preset test frequency is reached: according to the test parameters, controlling an alternating current contactor to execute a current control instruction of on-off operation by a control circuit; in the process of executing the on-off operation of the alternating current contactor, the current waveform and the voltage waveform of the alternating current contactor are collected, so that the alternating current contactor can execute large-current, high-voltage and electrical life tests in a vibration environment.

Description

Technical Field

[0001] The invention relates to an electrical life test method and device for an AC contactor, belonging to the technical field of AC contactors. Background Art

[0002] AC contactors are generally used to frequently connect and disconnect AC main circuits such as motors and large-capacity control circuits. They have strong switching capabilities, can meet high-power production needs, and can also achieve remote control. Therefore, they are widely used in production and life.

[0003] In recent years, with the development of new power systems, more and more AC contactors are used on the power consumption side. However, the working environment of some contactors (such as railways, ships, coal mines, wind turbines, etc.) is relatively harsh. Contactors are in various harsh working environments for a long time. Vibration stress will cause uncertain changes in the contact pressure of the contacts in the contactor system and the electromagnetic system, causing the contactor to malfunction and contact failure. In severe cases, it will cause irreparable losses. Therefore, the vibrating working environment will have a direct and important impact on the electrical life of the contactor.

[0004] The published text of the Chinese invention patent application with the authorization announcement number CN102253333B discloses an AC contactor electrical life test device and a control method thereof, wherein the device is composed of a test control cabinet, a test cabinet, a 1 / 6Ue power cabinet and a load cabinet; it is controlled by an industrial computer and can automatically and accurately complete the AC contactor electrical life test, but it cannot monitor the impact of the vibration environment on the dynamic characteristics of the contactor in real time, and it can only perform low-voltage and low-current tests, and cannot perform medium-voltage tests. Summary of the invention

[0005] The object of the present invention is to provide an electrical life test method and device for an AC contactor, so as to solve the problem that a medium voltage test cannot be performed on an AC contactor in a vibration environment.

[0006] To achieve the above object, on the one hand, the present invention provides an electrical life test method for an AC contactor, comprising: According to the usage category of the AC contactor, the current source circuit and the voltage source circuit are respectively regulated so that the current source circuit outputs a target current to the AC contactor and the voltage source circuit outputs a target voltage to the AC contactor; Configure the test parameters of the current electrical life test; Start the vibration table fixedly connected to the AC contactor; According to the test parameters, the following loop control is performed until a preset number of tests is reached: according to the test parameters, a current control instruction is output to the AC contactor to make the AC contactor perform an on-off operation; during the on-off operation of the AC contactor, the current waveform and voltage waveform of the AC contactor are collected.

[0007] Furthermore, according to the usage category of the AC contactor, the number of capacitor groups and the charging voltage in the current source loop are adjusted so that the current source loop outputs the target current to the AC contactor.

[0008] Furthermore, according to the usage category of the AC contactor, the connection state of the capacitor in the voltage source circuit and the tap size of the reactor are adjusted so that the voltage source circuit outputs the target voltage to the AC contactor.

[0009] Furthermore, the vibration table vibrates according to preset vibration parameters.

[0010] On the other hand, the present invention provides an electrical life test device for an AC contactor, comprising a main circuit system for outputting a target current and a target voltage to the AC contactor under test, wherein the main circuit system is used to be connected to the three phases of the AC contactor under test; And, a vibration table for providing vibration to the AC contactor, wherein the vibration table is used to be fixedly connected to the AC contactor.

[0011] Furthermore, the main circuit system includes a current source circuit and a voltage source circuit, wherein the current source circuit is provided with an adjustable load for outputting a target current to the AC contactor; and the voltage source circuit is provided with an adjustable load for outputting a target voltage to the AC contactor.

[0012] Furthermore, the adjustable load of the current source loop includes a capacitor; and the adjustable load of the voltage source loop includes a capacitor and a reactor.

[0013] Furthermore, the main circuit system also includes a test product circuit connected in series with the AC contactor under test, wherein the test product circuit includes a first test product circuit and a second test product circuit connected in parallel, wherein the first test product circuit includes a first test product; and the second test product circuit includes a transformer and a second test product connected in series.

[0014] Furthermore, the main circuit system also includes an adjustable resistor and an adjustable reactance for being connected in series with the AC contactor to be tested.

[0015] The beneficial effects of the present invention are as follows: according to the usage category of the AC contactor, the current source circuit and the voltage source circuit are respectively regulated so that the current source circuit outputs a target current to the AC contactor, and the voltage source circuit outputs a target voltage to the AC contactor; the test parameters of the current electrical life test are configured; a vibration table fixedly connected to the AC contactor is started; according to the test parameters, the following cyclic control is performed until a preset number of tests is reached: according to the test parameters, a current control instruction for the AC contactor to perform an on-off operation is output to the AC contactor; in the process of the AC contactor performing an on-off operation, the current waveform and the voltage waveform of the AC contactor are collected, so that the AC contactor is provided with a large current and a high voltage, and the vibration environment of the AC contactor is set by using the vibration table, so that the AC contactor can perform an electrical life test under a large current, high voltage and vibration environment, so that the test results are more in line with the actual application requirements of the AC contactor, and it is also convenient for researchers to develop and update the AC contactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic flow chart of an electrical life test method for an AC contactor according to one aspect of the present invention; Figure 2 It is a schematic diagram of the structure of an electrical life test platform of an electrical life test method for an AC contactor in an actual application scenario according to one aspect of the present invention; Figure 3 It is a circuit structure diagram of a main circuit system of an electrical life test device for an AC contactor in an actual application scenario according to another aspect of the present invention; Figure 4 It is a circuit structure diagram of a power supply in a main circuit system of an electrical life test device for an AC contactor in another aspect of the present invention in an actual application scenario; Figure 5 It is a layout structure diagram of a main circuit system of an electrical life test device for an AC contactor in an actual application scenario according to another aspect of the present invention; Figure 6 It is a structural schematic diagram of a control system of an electrical life test device for an AC contactor according to another aspect of the present invention in an actual application scenario. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0018] The inventive concept of the present invention is: in order to overcome the problem that the AC contactor cannot be tested for electrical life in a medium voltage and vibration environment, a current source circuit is used to provide a large current, a voltage source circuit is used to provide a high voltage, and a vibration table is combined to create a vibration environment for the AC contactor, so that the AC contactor can be tested for electrical life in a medium voltage vibration environment, thereby forming an electrical life test that fits the actual application environment of the AC contactor, making the test results more referenceable.

[0019] Method Example 1: On the one hand, the present invention provides an electrical life test method for an AC contactor, such as Figure 1 FIG. 1 is a flow chart of an electrical life test method for an AC contactor according to one aspect of the present invention, wherein the method comprises steps S11 to S14, specifically: Step S11, respectively regulating the current source circuit and the voltage source circuit according to the usage category of the AC contactor, so that the current source circuit outputs a target current to the AC contactor, and the voltage source circuit outputs a target voltage to the AC contactor; the target current refers to a large current provided to the AC contactor to enable the AC contactor to be in a medium-voltage operating environment; the target voltage refers to a high voltage provided to the AC contactor to enable the AC contactor to be in a medium-voltage operating environment.

[0020] Here, the use category of the AC contactor includes but is not limited to other use categories such as AC-1 use category, or AC-2 use category, or AC-3 use category, or AC-4 use category, and different test samples and their connection methods will be constructed according to different use categories. The specific use category selection can be selected according to the needs of different AC contactors. In the preferred embodiment of the present application, the use category of the preferred AC contactor is AC-3 use category, and correspondingly, test samples KM1 and test samples KM2 are used, and KM1 and KM2 are connected in parallel; at the same time, the current source circuit and the voltage source circuit are adjusted according to different use types. Specifically, according to the use category of the AC contactor, the number of capacitor groups and the charging voltage in the current source circuit are adjusted so that the current source circuit outputs the target current to the AC contactor; according to the use category of the AC contactor, the connection state of the capacitor in the voltage source circuit and the tap size of the reactor are adjusted so that the voltage source circuit outputs the target voltage to the AC contactor, and the voltage source and current source are used to regulate high voltage and high current, and achieve the reliability of the electrical life test under different currents, different currents and different test samples.

[0021] Step S12, configuring the test parameters of the current electrical life test; the test parameters herein include but are not limited to the test product model, the number of test products, the on time, the off time, the on-off frequency, and any one or more parameters of the relevant electrical life test.

[0022] Step S13, start the vibration table fixedly connected to the AC contactor; here, the vibration table vibrates according to preset vibration parameters, and the vibration parameters can be set according to the characteristics of different application environments, for example, vibration parameters of railway environment, vibration parameters of ship environment, vibration parameters of coal mine environment, vibration parameters of separation generator, etc. And, in actual application scenarios, the AC contactor will be fixed by a horizontal table top and a vertical table top.

[0023] Step S14, according to the test parameters, execute the following loop control until the preset number of tests is reached: according to the test parameters, output the current control instruction to the AC contactor to make the AC contactor perform the on-off operation; during the process of the AC contactor performing the on-off operation, collect the current waveform and voltage waveform of the AC contactor.

[0024] Through the above steps S11 to S14, the problem that the AC contactor cannot be tested for electrical life under medium voltage and vibration environment is overcome, and the actual application environment of the AC contactor is adapted, making the test results more referenceable.

[0025] In a preferred embodiment of the present invention, the AC contactor to be tested is preferably only the test piece A, and the current source circuit and the voltage source circuit are regulated according to the AC-3 usage category of the test piece A, so that the current source circuit and the voltage source circuit provide the target current of 600A and the target voltage of 10KV for the test piece A, and the accompanying test pieces KM1 and KM2 connected in parallel are set; the test piece model, the number of test pieces, the on-time, the off-time and the on-off frequency and other test parameters are configured for the test piece A; the vibration table starts to vibrate according to the preset vibration parameters under the coal mine working environment; according to the test parameters of the test piece A, the first control instruction for performing the on-off operation is output to the test piece A, and the current waveform and the voltage waveform generated by the test piece A in response to the first control instruction are collected, and then the second control instruction for performing the on-off operation is output to the test piece A, and the current waveform and the voltage waveform generated by the test piece A in response to the second control instruction are collected, until the number of tests of the test piece A reaches the preset m times, and the electrical life test of the test piece A in the high current, high voltage and vibration environment of the coal mine is completed.

[0026] It should be noted that in the actual application scenario of the present invention, the stop condition of the cycle control also includes the failure of the sample, that is, in step S14, when the sample fails during the cycle control according to the test parameters, the test is stopped, wherein the determination of the sample failure includes but is not limited to a preset failure voltage threshold or a preset failure current threshold. Specifically, when the current or voltage generated by the sample reaches the corresponding threshold during the cycle control of the sample, the sample is determined to have failed. At this time, the electrical life test of the sample is stopped immediately, and the test results of the sample failure are uploaded to the host computer, so that researchers can check the sample failure information on the host computer and evaluate the electrical life of the sample.

[0027] Method Example 2: like Figure 2 As shown, it is a schematic diagram of the structure of an electrical life test platform of an electrical life test method for an AC contactor in an actual application scenario according to one aspect of the present invention, wherein, firstly, the main circuit area is mainly used for dynamic characteristic adjustment, that is, the required target current and target voltage are dynamically adjusted according to different requirements of the AC contactor (including the test product and the accompanying test product), wherein the target current or target voltage can be achieved by adjusting the resistance of the DC power supply, and the target current or target voltage can also be achieved by adjusting the load cabinet of the AC power supply, specifically, the knife switch and the conversion switch on the load cabinet are turned to a position consistent with the calculated load parameters, wherein the load cabinet includes loads such as capacitors and reactors.

[0028] Secondly, the AC contactor is fixedly connected to the electric vibration table, and the test parameters are set on the Labview platform of the industrial computer. The industrial computer sends analog signals to the drive circuit through the high-speed multi-functional data acquisition card according to the set test parameters, so as to drive the control circuit to output control instructions to the test product / accompanying test product coil to perform on-off operations. At the same time, the electric vibration table starts to vibrate according to the preset vibration parameters.

[0029] Next, when the AC contactor performs the on-off operation, the power supply voltage, contact voltage and loop current are collected respectively through the Hall voltage sensor and the Hall current sensor, the contact pressure signal is collected through the charge amplifier, and the collected current, voltage and pressure signal data are converted into current waveform and voltage waveform through the signal conditioning module; the current waveform and voltage waveform are then fed back to the Labview platform of the industrial computer through a high-speed multi-functional data acquisition card for storage.

[0030] Finally, the industrial computer continues to output control instructions, and the Hall voltage sensor, Hall current sensor and charge amplifier continue to collect data until the preset number of tests for the AC contactor is reached. During the test, the control instructions and data collection work synchronously. Each time the AC contactor is turned on and off, the current waveform and voltage waveform are synchronously collected and displayed, and automatically saved in the specified folder.

[0031] On the other hand, the present invention also provides an electrical life test device for an AC contactor, which includes a main circuit system for outputting a target current and a target voltage to the AC contactor under test, wherein the main circuit system is used to be connected to the three phases of the AC contactor under test, and a vibration table for providing vibration to the AC contactor, wherein the vibration table is used to be fixedly connected to the AC contactor.

[0032] It should be noted that the main circuit system includes a current source circuit and a voltage source circuit, wherein the current source circuit is provided with an adjustable load for outputting a target current to the AC contactor; the voltage source circuit is provided with an adjustable load for outputting a target voltage to the AC contactor, specifically, the adjustable load of the current source circuit includes a capacitor; the adjustable load of the voltage source circuit includes a capacitor and a reactor.

[0033] In addition, the main circuit system also includes a test product circuit for being connected in series with the AC contactor under test and an adjustable resistor and an adjustable reactance for being connected in series with the AC contactor under test, wherein the test product circuit includes a first test product circuit and a second test product circuit connected in parallel, wherein the first test product circuit includes a first test product; and the second test product circuit includes a transformer and a second test product connected in series.

[0034] Device Example 1: like Figure 3 As shown, it is a circuit structure diagram of the main circuit system of an electrical life test device for an AC contactor in an actual application scenario according to another aspect of the present invention, wherein the main circuit system includes a power supply, a circuit breaker QF, a fuse FU, a test circuit, a contactor test, an adjustable resistor R and an adjustable reactance L connected in series in sequence, wherein the test circuit includes a first test circuit and a second test circuit connected in parallel, wherein the first test circuit includes a test product KM1; the second test circuit includes a transformer T and a second test product KM2 connected in series; R and L are adjustable resistors and adjustable inductors in the load cabinet, which can realize the function of adjusting current and power factor.

[0035] In the actual application scenario, the AC contactor test product is installed on the vibration platform according to the specified requirements, and the tested AC contactor test product is connected to the load to ensure reliable connection and normal operation. Phase A, phase B and phase C are connected to the input and output of the test product in turn, phase N is short-circuited, and two wires are led out and connected to the two control ports of the AC contactor through a circuit breaker. The circuit breaker is a protection switch to prevent excessive current from damaging the contactor. The voltage between the two wires is 220 V, which is used to energize the coil of the AC contactor to close the AC contactor. The three-phase power supply and load are both connected in Y type.

[0036] Device Example 2: like Figure 4As shown, it is a circuit structure diagram of the power supply in the main circuit system of an electrical life test device of an AC contactor in another aspect of the present invention in an actual application scenario, wherein the power supply includes a current source circuit and a voltage source circuit, wherein the current source circuit and the voltage source circuit are respectively connected in parallel to the AC contactor (including the test product and the accompanying test product), and the current source circuit is composed of a switch K, a fuse FU, an adjustable reactance Li and a capacitor Ci connected in parallel with each other; the voltage source circuit is composed of an adjustable reactance, a discharge gap TR and a capacitor Cu.

[0037] When the current source circuit and the voltage source circuit are regulated respectively according to the usage category of the AC contactor, the current source circuit selects the number of capacitor groups and the charging voltage to be incorporated according to the target current and the test method; the voltage source circuit calculates the capacitance value and inductance according to different target voltages and target currents, selects the series-parallel capacitors according to the capacitance value, and designs the tap size of the reactor according to the inductance. The circuit breaker and the fast fuse can cut off the power supply when the main circuit is overloaded or short-circuited to protect the test circuit and equipment.

[0038] Device Example 3: In the present invention, if the AC contactor under test does not need to be subjected to an electrical life test under a medium voltage environment, the power supply can be replaced by a large current generator to provide a small current for the AC contactor under test.

[0039] Specifically, Figure 5 As shown, it is a layout structure diagram of the main circuit system of an AC contactor electrical life test device in another aspect of the present invention in an actual application scenario, wherein a vibration table drive control device, a main circuit control system and a control console are provided on the left side of the main circuit system, wherein the vibration table drive control device mainly includes a power amplifier part and a vibration control system, wherein the power amplifier part includes a digital switching power amplifier (including an excitation power supply); the control system mainly includes a programmable controller PLC, a single-chip microcomputer and a relay, etc. The main circuit system mainly includes a power supply area (i.e., a large current generator), a test product circuit area, a contactor test product area and an adjustable resistance reactance area, wherein the power supply area and the test product circuit area are connected in series, the test product circuit area and the contactor test product area are connected in series, and the contactor test product area and the adjustable resistance reactance area are connected in series.

[0040] Device Example 4: In the present invention, an electrical life test device for an AC contactor also includes a control system and a measurement system, wherein the control system is composed of a touch screen, a programmable controller PLC, and a relay circuit board; the measurement system is composed of a pressure sensor, a Hall sensor, a signal conditioning module, and a data acquisition card.

[0041] like Figure 6As shown, it is a schematic diagram of the structure of the control system of an electrical life test device for an AC contactor in another aspect of the present invention in an actual application scenario, wherein the control system uses a touch screen plus a programmable controller (PLC) to control a relay circuit board to control the connection and disconnection of the AC contactor, and the corresponding input and output signal lines are connected to the terminals of the PLC. When the function of the control system needs to be changed, the program can be modified online or offline with a programmer. The same PLC device is used for different AC contactors, but the input and output components and application software are different.

[0042] In summary, the present invention can carry out electrical life reliability experiments on AC contactors. During the experiment, arcing time, arcing energy, contact resistance, contact voltage drop, etc. can be monitored in real time, which can shorten the product development cycle and realize reliability testing under different currents, voltages, loads and vibration conditions. It has the ability to test the dynamic characteristics of medium and low voltage switchgear, collect electrical life performance degradation parameters and conduct electrical life testing. Relying on platform construction, it focuses on overcoming the problems of full electrical life experiments on switchgear, provides experimental support for improving the structural strength and seismic resistance of products, enhances product quality control, eliminates safety risks during product use, and improves the pass rate of the factory test stage. At the same time, in the product development stage, it is not necessary to make a complete contactor, and the detachable arc extinguishing chamber can be placed in the circuit to test the electrical life, thereby reducing mold waste and development cycle of product development.

[0043] In addition, the present invention combines the unique vibration use environment and load characteristics of coal mines, etc., to develop a set of AC contactor electrical life test system with high reliability evaluation, which is conducive to the research and development of more excellent new mining AC vacuum contactors, improving production safety in coal mines, etc., and solving the problem of coal mining machine contactors. In the future, it can also provide experimental support for the research of other types of products with high electrical life and mechanical electrical life, including small vacuum circuit breakers, molded case circuit breakers, other AC and DC contactors and other medium and low voltage switch products, providing long-term experimental research support for the development of medium and low voltage switches with special parameters and application scenarios under new power systems.

Claims

1. A method for testing the electrical life of an AC contactor, characterized in that: include: According to the usage category of the AC contactor, the current source circuit and the voltage source circuit are respectively regulated so that the current source circuit outputs a target current to the AC contactor and the voltage source circuit outputs a target voltage to the AC contactor; Configure the test parameters of the current electrical life test; Start the vibration table fixedly connected to the AC contactor; According to the test parameters, the following loop control is performed until a preset number of tests is reached: according to the test parameters, a current control instruction is output to the AC contactor to make the AC contactor perform an on-off operation; during the on-off operation of the AC contactor, the current waveform and voltage waveform of the AC contactor are collected.

2. The electrical life test method of the AC contactor according to claim 1, characterized in that: According to the usage category of the AC contactor, the number of capacitor groups and the charging voltage in the current source circuit are adjusted so that the current source circuit outputs the target current to the AC contactor.

3. The electrical life test method of the AC contactor according to claim 1, characterized in that: According to the usage category of the AC contactor, the connection state of the capacitor in the voltage source circuit and the tap size of the reactor are adjusted so that the voltage source circuit outputs the target voltage to the AC contactor.

4. The electrical life test method of the AC contactor according to claim 1, characterized in that: The vibration table vibrates according to preset vibration parameters.

5. An electrical life test device for an AC contactor, characterized in that: It includes a main circuit system for outputting a target current and a target voltage to the AC contactor under test, wherein the main circuit system is used to be connected to the three phases of the AC contactor under test; And, a vibration table for providing vibration to the AC contactor, wherein the vibration table is used to be fixedly connected to the AC contactor.

6. The electrical life test device of the AC contactor according to claim 5, characterized in that: The main circuit system includes a current source circuit and a voltage source circuit, wherein the current source circuit is provided with an adjustable load for outputting a target current to the AC contactor; and the voltage source circuit is provided with an adjustable load for outputting a target voltage to the AC contactor.

7. The electrical life test device of the AC contactor according to claim 6, characterized in that: The adjustable load of the current source loop includes a capacitor; the adjustable load of the voltage source loop includes a capacitor and a reactor.

8. The electrical life test device for AC contactor according to claim 5, characterized in that: The main circuit system also includes a test product circuit connected in series with the AC contactor under test, wherein the test product circuit includes a first test product circuit and a second test product circuit connected in parallel, wherein the first test product circuit includes a first test product; and the second test product circuit includes a transformer and a second test product connected in series.

9. The electrical life test device for AC contactor according to claim 5, characterized in that: The main circuit system also includes an adjustable resistor and an adjustable reactance which are connected in series with the AC contactor to be tested.

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