Protective device for withstand voltage test of electrical equipment and withstand voltage test system

Abstract

The invention discloses a protection device for a withstand voltage test of electrical equipment and a withstand voltage test system, and the protection device comprises a test connection unit which is suitable for connecting the to-be-tested electrical equipment and test voltage output equipment, a test loop is formed between the voltage input end of the to-be-tested electrical equipment and the output end of the test voltage output equipment; and the protection unit is configured to block the test loop under the condition that the test connection unit is in poor contact so as to protect the to-be-tested electrical equipment. Therefore, when the electrical equipment is subjected to the withstand voltage test, the safety of the electrical equipment can be protected, and the safety of the withstand voltage test is effectively improved.

Description

Technical Field

[0001] The invention relates to the field of electronic equipment testing, and in particular to a protective device and a voltage withstand test system for electrical equipment. Background Art

[0002] Among various tests on electrical equipment, DC insulation withstand voltage test is of great significance for ensuring the reliable operation of electrical equipment and personal safety. At present, the general method for implementing DC insulation withstand voltage test is to connect the positive pole of the DC test voltage output device to the input terminal of the device under test, and connect the protection ground of the device under test to the negative pole of the DC test voltage output device. When the test is running, the DC voltage is applied to the insulation system of the device under test. At this time, the insulation system status of the device under test can be evaluated by the leakage current of the device under test, thereby realizing the DC insulation withstand voltage test of the device under test. However, in actual testing, due to poor contact or aging of the connectors connecting the DC power output device and the device under test, this will cause damage to the internal electronic circuit of the device under test, thereby reducing the safety of the DC insulation withstand voltage test. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the first purpose of the present invention is to provide a protective device for a withstand voltage test of an electrical device, by arranging a test connection unit and a protection unit in the protective device, during the withstand voltage test, when the test connection unit has a poor contact, the protection unit will block the test circuit to prevent the reverse current generated by the poor contact from damaging the electrical device to be tested, thereby protecting the safety of the electrical device and further improving the safety of the withstand voltage test.

[0004] A second objective of the present invention is to provide a withstand voltage test system.

[0005] To achieve the above-mentioned purpose, an embodiment of the first aspect of the present invention proposes a protective device for voltage withstand testing of electrical equipment, comprising: a test connection unit, the test connection unit is suitable for connecting the electrical equipment to be tested and the test voltage output device, so that a test circuit is formed between the voltage input terminal of the electrical equipment to be tested and the output terminal of the test voltage output device; a protection unit, which is configured to block the test circuit in the event of poor contact of the test connection unit, so as to protect the electrical equipment to be tested.

[0006] According to the protective device of the embodiment of the present invention, a test connection unit and a protection unit are arranged in the protective device. During the withstand voltage test, when the test connection unit has poor contact, the protection unit will block the test circuit to prevent the reverse current generated by the poor contact from damaging the electrical equipment under test, thereby protecting the safety of the electrical equipment and further improving the safety of the withstand voltage test.

[0007] According to one embodiment of the present invention, the protection unit includes a first protection module, which is arranged between the positive output terminal of the test voltage output device and the positive input terminal of the electrical device to be tested, or the first protection module is arranged between the negative output terminal of the test voltage output device and the protection ground of the electrical device to be tested.

[0008] According to one embodiment of the present invention, the first protection module includes a first protection diode, wherein, when the first protection module is arranged between the positive output terminal of the test voltage output device and the positive input terminal of the electrical device to be tested, the anode of the first protection diode is connected to the positive output terminal of the test voltage output device, and the cathode of the first protection diode is connected to the positive connection terminal in the test connection unit; when the first protection module is arranged between the negative output terminal of the test voltage output device and the protection ground of the electrical device to be tested, the cathode of the first protection diode is connected to the negative output terminal of the test voltage output device, and the anode of the first protection diode is connected to the protection ground of the electrical device to be tested.

[0009] According to an embodiment of the present invention, the first protection module further includes an absorption circuit, which is connected in parallel with the first protection diode to absorb the discharge impact current generated in the test loop.

[0010] According to one embodiment of the present invention, the protection unit includes a first protection module and a second protection module, wherein the first protection module is arranged between the positive output terminal of the test voltage output device and the positive input terminal of the electrical device to be tested, and the second protection module is arranged between the positive output terminal of the test voltage output device and the negative input terminal of the electrical device to be tested; or the first protection module is arranged between the positive output terminal of the test voltage output device and the positive input terminal of the electrical device to be tested, and the second protection module is arranged between the negative output terminal of the test voltage output device and the protection ground of the electrical device to be tested.

[0011] According to one embodiment of the present invention, the first protection module includes a first protection diode, and the second protection module includes a second protection diode, wherein, when the first protection module is arranged between the positive output terminal of the test voltage output device and the positive input terminal of the electrical device to be tested, and the second protection module is arranged between the positive output terminal of the test voltage output device and the negative input terminal of the electrical device to be tested, the anode of the first protection diode is connected to the positive output terminal of the test voltage output device, the cathode of the first protection diode is connected to the positive connection terminal in the test connection unit, the anode of the second protection diode is connected to the positive output terminal of the test voltage output device, and the cathode of the first protection diode is connected to the negative connection terminal in the test connection unit; when the first protection module is arranged between the positive output terminal of the test voltage output device and the positive input terminal of the electrical device to be tested, and the second protection module is arranged between the negative output terminal of the test voltage output device and the protection ground of the electrical device to be tested, the anode of the first protection diode is connected to the positive output terminal of the test voltage output device, the cathode of the first protection diode is connected to the positive connection terminal in the test connection unit, the cathode of the second protection diode is connected to the negative output terminal of the test voltage output device, and the anode of the first protection diode is connected to the protection ground of the electrical device to be tested.

[0012] According to an embodiment of the present invention, the first protection module and the second protection module further include an absorption circuit respectively, and the absorption circuit is connected in parallel with the corresponding protection diode to absorb the discharge impact current generated in the test loop.

[0013] According to one embodiment of the present invention, the absorption circuit includes an absorption resistor and an absorption capacitor connected in series.

[0014] According to one embodiment of the present invention, the protection device further comprises a shorting switch, which is adapted to short-circuit the positive input terminal and the negative input terminal of the electrical device under test when the electrical device under test is subjected to a withstand voltage test.

[0015] According to one embodiment of the present invention, the electrical equipment to be tested includes at least one of a motor controller, a photovoltaic inverter, an industrial inverter and a household appliance frequency converter.

[0016] To achieve the above-mentioned purpose, the second aspect of the embodiment of the present invention proposes a voltage withstand test system for electrical equipment, including: a test voltage output device, configured to provide a DC test voltage to the electrical equipment to be tested; the aforementioned protective device, configured to protect the electrical equipment to be tested during the process of the test voltage output device performing a voltage withstand test on the electrical equipment to be tested.

[0017] According to the withstand voltage test system of the embodiment of the present invention, the aforementioned protection device can protect the safety of the electrical equipment to be tested when the withstand voltage test system performs a withstand voltage test on the electrical equipment to be tested, thereby improving the safety of the withstand voltage test system.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of the structure of a protection device for a withstand voltage test of electrical equipment according to an embodiment of the present invention;

[0020] Figure 2 is an output test voltage waveform diagram for a DC withstand voltage test according to an embodiment of the present invention;

[0021] Figure 3a to Figure 3b is a schematic diagram of the structure of a protection unit according to some embodiments of the present invention;

[0022] Figure 4 is a structural schematic diagram of a test connection unit according to an embodiment of the present invention;

[0023] Figure 5a to Figure 5b is a schematic diagram of the structure of a protection unit according to some other embodiments of the present invention;

[0024] Figure 6 FIG. 4 is a schematic structural diagram of a voltage withstand test system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0026] The following describes a protective device and a withstand voltage test system for electrical equipment according to an embodiment of the present invention with reference to the accompanying drawings.

[0027] Figure 1 FIG. 1 is a schematic diagram of a protective device 100 for a withstand voltage test of an electrical device according to an embodiment of the present invention. Figure 1 As shown, the protection device 100 includes: a test connection unit 110 and a protection unit 120 .

[0028] Among them, the test connection unit 110 is suitable for connecting the electrical equipment under test 200 and the test voltage output device 300 so that a test circuit is formed between the voltage input end of the electrical equipment under test 200 and the output end of the test voltage output device 300; the protection unit 120 is configured to block the test circuit when poor contact occurs in the test connection unit 110 to protect the electrical equipment under test 200.

[0029] Specifically, refer to Figure 1 As shown, when it is necessary to perform a DC withstand voltage test on the electrical device 200 to be tested, the test voltage output device 300 will be connected to the electrical device 200 to be tested through the test connection unit 110 in the protection device 100, so as to form a test loop from the positive output terminal of the test voltage output device 300, through the test connection unit 110, the input terminal of the electrical device 200 to be tested, to the negative output terminal of the test voltage output device 300, thereby realizing the DC withstand voltage test. During the test, the output test voltage change trend of the positive output terminal of the test voltage output device 300 is as shown in FIG. Figure 2 As shown, reference Figure 2 As shown, in the process of continuous decrease in the output test voltage, if the test connection unit 110 has poor contact, the electrical device 200 to be tested and the test voltage output device 300 may be disconnected and then reconnected in a short time, for example, disconnected at time t0 and then reconnected at time t1, then at time t1, the output test voltage has dropped from U1 to U2, however, since the electrical device 200 to be tested may have an energy storage element such as a capacitor, the voltage between the two ends of the electrical device 200 to be tested may still remain at U1, so at time t1, when the electrical device 200 to be tested and the test voltage output device 300 are reconnected, the voltage difference between the two may cause the capacitor element in the electrical device 200 to be tested to discharge, resulting in a large reverse discharge impact current in the test circuit, which may damage various electronic components in the electrical device 200, thereby reducing the safety of the DC withstand voltage test.

[0030] Therefore, a protection unit 120 is provided in an embodiment of the present invention. During a DC withstand voltage test, if the test connection unit 110 has poor contact and generates a reverse current, the protection unit 120 can block the test loop, thereby preventing the reverse current from damaging the electrical equipment and protecting the safety of the electrical equipment.

[0031] In the above embodiment, by setting a test connection unit and a protection unit in the protective device, during the voltage withstand test, when the test connection unit has poor contact, the protection unit will block the test circuit to prevent the reverse current generated by the poor contact from damaging the electrical equipment under test, thereby protecting the safety of the electrical equipment and further improving the safety of the voltage withstand test.

[0032] In some embodiments, reference Figure 3a and Figure 3b As shown, the protection unit 120 includes a first protection module 121, which is arranged between the positive output terminal of the test voltage output device 300 and the positive input terminal of the electrical device 200 to be tested, or the first protection module 121 is arranged between the negative output terminal of the test voltage output device 300 and the protection ground GND of the electrical device 200 to be tested.

[0033] Specifically, the first protection module 121 is used to block the test circuit when the test connection unit 110 has poor contact. Therefore, the first protection module 121 needs to be connected in series in the test circuit formed during the DC withstand voltage test. Figure 3a and Figure 3b As shown, when a DC withstand voltage test is performed on the electrical device 200 to be tested, the test circuit formed at this time is starting from the positive output terminal of the test voltage output device 300, passing through the positive input terminal of the electrical device 200 to be tested, the protective ground GND of the electrical device 200 to be tested, and finally to the negative output terminal of the test voltage output device 300. Therefore, the first protection module 121 can be set between the positive output terminal of the voltage output device 300 and the positive input terminal of the electrical device 200 to be tested, and can also be set between the negative output terminal of the test voltage output device 300 and the protective ground GND of the electrical device 200 to be tested, so as to block the test circuit when the test connection unit 110 has poor contact.

[0034] Further, the first protection module 121 includes a first protection diode D1, wherein, when the first protection module 121 is arranged between the positive output terminal of the test voltage output device 300 and the positive input terminal of the electrical device under test 200, the anode of the first protection diode D1 is connected to the positive output terminal of the test voltage output device 300, and the cathode of the first protection diode D1 is connected to the positive connection terminal in the test connection unit 110; when the first protection module 121 is arranged between the negative output terminal of the test voltage output device 300 and the protection ground GND of the electrical device under test 200, the cathode of the first protection diode D1 is connected to the negative output terminal of the test voltage output device 300, and the anode of the first protection diode D1 is connected to the protection ground GND of the electrical device under test 200.

[0035] Specifically, since the first protection module 121 is used to block the test circuit when a reverse impact current is generated in the test circuit to suppress the impact current, the first protection diode D1 can be used to form the first protection module 121, and the unidirectional conduction characteristic of the diode is utilized to achieve the function of blocking the test circuit; at the same time, the anode and cathode of the first protection diode D1 need to be adjusted accordingly according to the setting method of the first protection module 121, so that when the protection device is performing a withstand voltage test, the current in the test circuit can flow normally through the first protection diode D1.

[0036] For example, refer to Figure 3a As shown, when the first protection module 121 is arranged between the positive output terminal of the test voltage output device 300 and the positive input terminal of the electrical device to be tested 200, the current direction of the test circuit during the withstand voltage test is, flowing from the positive output terminal of the voltage output device 300 into the positive connection terminal of the test connection unit 110, and then into the positive input terminal of the electrical device to be tested 200. Therefore, the anode of the first protection diode D1 can be connected to the positive output terminal of the test voltage output device 300, and the cathode of the first protection diode D1 can be connected to the positive connection terminal in the test connection unit 110.

[0037] Alternatively, refer to Figure 3b As shown, when the first protection module 121 is arranged between the negative output terminal of the test voltage output device 300 and the protection ground GND of the electrical device 200 to be tested, the current direction of the test circuit during the withstand voltage test is to flow from the protection ground GND of the electrical device 200 to the negative output terminal of the test voltage output device 300. Therefore, the cathode of the first protection diode D1 is connected to the negative output terminal of the test voltage output device 300, and the anode of the first protection diode D1 is connected to the protection ground GND of the electrical device 200 to be tested, so that the first protection diode does not affect the normal DC withstand voltage test.

[0038] Furthermore, the first protection module 121 further includes an absorption circuit 1211 , which is connected in parallel with the first protection diode D1 to absorb the discharge impact current generated in the test loop.

[0039] Specifically, refer to Figure 3a As shown, in order to eliminate the discharge impact current caused by the voltage difference between the test voltage output device 300 and the electrical device to be tested 200 as quickly as possible, an absorption circuit 1211 can be set in parallel with the first protection diode D1, so that the discharge impact current can be quickly absorbed to avoid the impact current from damaging the electrical device, thereby further improving the safety of the withstand voltage test.

[0040] Furthermore, the absorption circuit 1211 includes an absorption resistor R and an absorption capacitor C connected in series.

[0041] Specifically, the absorption resistor R is mainly used to limit the discharge and charging current generated in the test circuit to protect the various electronic components in the test circuit. The absorption capacitor C is mainly used for charging and discharging to absorb the reverse impact current in the test circuit to realize the function of the absorption circuit to absorb the discharge impact current.

[0042] In some embodiments, reference Figure 4 As shown, the protection device 100 further includes a shorting switch K, which is suitable for short-circuiting the positive input terminal and the negative input terminal of the electrical device 200 under test when the electrical device 200 under test is subjected to a withstand voltage test.

[0043] Specifically, in the DC withstand voltage test, some test environments require that the positive input terminal and the negative input terminal of the electrical equipment under test 200 be short-circuited and then connected to the positive output terminal of the test voltage output device 300. Therefore, a short-circuiting switch K can be set in the protection device 100. The positive input terminal and the negative input terminal of the electrical equipment under test can be short-circuited by closing the short-circuiting switch K to perform the corresponding DC withstand voltage test.

[0044] Optionally, since in some test environments, only the positive input terminal or the negative input terminal of the electrical device under test 200 needs to be connected to the positive output terminal of the test voltage output device 300, a first switch S1 and a second switch S2 may be provided in the test connection unit 110, wherein a first end of the first switch S1 is connected to a second end of the short-circuit switch K, a second end of the first switch S1 is connected to the positive input terminal of the electrical device under test, a first end of the second switch S2 is connected to a first end of the short-circuit switch K, and a second end of the second switch S2 is connected to the negative input terminal of the electrical device under test, Therefore, when only the positive input terminal of the electrical device 200 under test needs to be connected to the positive output terminal of the voltage output device 300, the first switch S1 can be controlled to be turned on, and the second switch S2 and the short-circuit switch K can be controlled to be turned off; when only the negative input terminal of the electrical device 200 under test needs to be connected to the positive output terminal of the voltage output device 300, the second switch S2 and the short-circuit switch K can be controlled to be turned on, and the first switch S1 can be turned off; when both the positive input terminal and the negative input terminal of the electrical device 200 under test need to be connected to the positive output terminal of the voltage output device 300, the three switches can be controlled to be turned on at the same time.

[0045] Therefore, by setting a short-circuit switch in the protective device and setting a first switch and a second switch in the test connection unit 110, the protective device can realize the connection between the positive output terminal of the voltage output device and one or both of the positive input terminal and the negative input terminal in the electrical device to be tested, thereby meeting the requirements of various test environments of the withstand voltage test.

[0046] In some embodiments, reference Figure 5a to Figure 5bAs shown, the protection unit 120 includes a first protection module 121 and a second protection module 122, wherein the first protection module 121 is arranged between the positive output terminal of the test voltage output device 300 and the positive input terminal of the electrical device 200 to be tested, and the second protection module 122 is arranged between the positive output terminal of the test voltage output device 300 and the negative input terminal of the electrical device 200 to be tested; or the first protection module 121 is arranged between the positive output terminal of the test voltage output device 300 and the positive input terminal of the electrical device 200 to be tested, and the second protection module 122 is arranged between the negative output terminal of the test voltage output device 300 and the protection ground GND of the electrical device 200 to be tested.

[0047] Specifically, in some test environments, there may be branches of the test loop in the test connection unit 100, such as Figure 4 As shown, when the positive input terminal and the negative input terminal of the electrical device 200 to be tested need to be short-circuited for a DC withstand voltage test, there are two branches in the test circuit, one is from the test voltage output device 300 to the positive input terminal of the electrical device 200 to be tested, and the other is from the test voltage output device 300 to the negative input terminal of the electrical device 200 to be tested. At this time, if there is only a single protection module in the protection unit 120, it may not be possible to achieve comprehensive protection for the electrical device 200 to be tested. Therefore, refer to Figure 5a to Figure 5b As shown, a first protection module 121 and a second protection module 122 may be provided in the protection unit 120 to provide a comprehensive protection effect of the withstand voltage test. The first protection module 121 and the second protection module 122 may be provided in a variety of ways, for example, referring to Figure 5a As shown, the first protection module 121 can be arranged between the positive output terminal of the test voltage output device 300 and the positive input terminal of the electrical device 200 to be tested, and the second protection module 122 can be arranged between the positive output terminal of the test voltage output device 300 and the negative input terminal of the electrical device 200 to be tested. When performing a withstand voltage test, the first protection module 121 and the second protection module 122 can respectively suppress the impact current of their own branches, thereby providing a comprehensive protection effect for the electrical device 200 to be tested.

[0048] Alternatively, refer to Figure 5bAs shown, the first protection module 121 can be arranged between the positive output terminal of the test voltage output device 300 and the positive input terminal of the electrical device 200 under test, and the second protection module 122 can be arranged between the negative output terminal of the test voltage output device 300 and the protection ground GND of the electrical device 200 under test. At this time, the first protection module 121 and the second protection module 122 are both arranged in the main circuit of the test loop, so both can simultaneously suppress the impact current in the two branches in the test loop to provide comprehensive protection for the electrical device 200 under test. The above two methods can make the protection effect of the protection device on the electrical equipment under test more comprehensive.

[0049] For further reference, Figure 5a to Figure 5b As shown, the first protection module 121 includes a first protection diode D1, and the second protection module 122 includes a second protection diode D2, wherein, when the first protection module 121 is arranged between the positive output terminal of the test voltage output device 300 and the positive input terminal of the electrical device 200 to be tested, and the second protection module 122 is arranged between the positive output terminal of the test voltage output device 300 and the negative input terminal of the electrical device 200 to be tested, the anode of the first protection diode D1 is connected to the positive output terminal of the test voltage output device 300, the cathode of the first protection diode D1 is connected to the positive connection terminal in the test connection unit 110, the anode of the second protection diode D2 is connected to the positive output terminal of the test voltage output device 300, and the first protection diode D 1 is connected to the negative connection terminal in the test connection unit 110; when the first protection module 121 is arranged between the positive output terminal of the test voltage output device 300 and the positive input terminal of the electrical device 200 to be tested, and the second protection module 122 is arranged between the negative output terminal of the test voltage output device 300 and the protection ground GND of the electrical device 200 to be tested, the anode of the first protection diode D1 is connected to the positive output terminal of the test voltage output device 300, the cathode of the first protection diode D1 is connected to the positive connection terminal in the test connection unit 110, the cathode of the second protection diode D2 is connected to the negative output terminal of the test voltage output device 300, and the anode of the first protection diode D1 is connected to the protection ground GND of the electrical device 200 to be tested.

[0050] Specifically, since both the first protection diode D1 and the second protection diode D2 need to suppress the reverse surge current in the test loop, the anode and cathode of the first protection diode D1 and the second protection diode D2 need to be set based on the positions of the first protection module 121 and the second protection module 122. Figure 5aAs shown, when the first protection module 121 is arranged between the positive output terminal of the test voltage output device 300 and the positive input terminal of the electrical device 200 to be tested, and the second protection module 122 is arranged between the positive output terminal of the test voltage output device 300 and the negative input terminal of the electrical device 200 to be tested, the anode of the first protection diode D1 can be connected to the positive output terminal of the test voltage output device 300, the cathode of the first protection diode D1 can be connected to the positive connection terminal in the test connection unit 110, the anode of the second protection diode D2 can be connected to the positive output terminal of the test voltage output device 300, and the cathode of the first protection diode D1 is connected to the negative connection terminal in the test connection unit 110, so as not to affect the normal operation of the test loop. Similarly, reference Figure 5b As shown, when the first protection module 121 is arranged between the positive output terminal of the test voltage output device 300 and the positive input terminal of the electrical device 200 to be tested, and the second protection module 122 is arranged between the negative output terminal of the test voltage output device 300 and the protection ground GND of the electrical device 200 to be tested, the anode of the first protection diode D1 can be connected to the positive output terminal of the test voltage output device 300, the cathode of the first protection diode D1 can be connected to the positive connection terminal in the test connection unit 110, the cathode of the second protection diode D2 can be connected to the negative output terminal of the test voltage output device 300, and the anode of the first protection diode D1 can be connected to the protection ground GND of the electrical device 200 to be tested, so as to not affect the normal operation of the test circuit and achieve the suppression effect of the reverse impact current.

[0051] Furthermore, the first protection module 121 and the second protection module 122 further include an absorption circuit 1211 respectively. The absorption circuit 1211 is connected in parallel with the corresponding protection diode to absorb the discharge impact current generated in the test loop.

[0052] Specifically, the configuration and structure of the absorption circuit 1211 are as follows: Figure 3a As shown, setting an absorption circuit 1211 in the first protection module 121 and the second protection module 122 can enhance the absorption effect of the discharge impact current generated in the test circuit, thereby further enhancing the protection effect of the protection unit 120 on the electrical equipment 200 under test. For the specific principle, please refer to the aforementioned description of the principle of the absorption circuit 1211, which will not be repeated here.

[0053] In some embodiments, the electrical device 200 under test includes at least one of a motor controller, a photovoltaic inverter, an industrial inverter, and a household appliance inverter.

[0054] Specifically, since electrical equipment such as motor controllers, photovoltaic inverters, industrial inverters and household appliance frequency converters all contain capacitive components and their internal electronic circuits are relatively delicate and easily damaged, applying the protective device 100 to the withstand voltage test of these devices can protect the circuit safety of these devices and thereby improve the safety of the withstand voltage test.

[0055] Optionally, the protective device in the aforementioned embodiment can be integrated with the test voltage output device 300, or can be integrated with the electrical device under test 200, so as to protect the safety of the electrical device under test when these devices are subjected to a withstand voltage test and improve the safety of the withstand voltage test.

[0056] In summary, according to the protection device of the embodiment of the present invention, a test connection unit and a protection unit are set in the protection device. During the withstand voltage test, when the test connection unit has poor contact, the diode in the protection unit will block the test circuit to prevent the reverse current caused by the poor contact from damaging the electrical equipment to be tested, thereby protecting the safety of the electrical equipment; at the same time, when there is more than one test circuit, protection modules are set in different branches of the test circuit, thereby achieving comprehensive protection of the safety of the electrical equipment; in addition, by connecting an absorption circuit composed of an absorption resistor and an absorption capacitor in parallel to the diode of each protection module, the discharge impact current in the test circuit can be further suppressed, thereby effectively improving the safety of the withstand voltage test.

[0057] Corresponding to the above embodiment, the present invention also provides a withstand voltage test system for electrical equipment, referring to Figure 6 As shown, the withstand voltage test system includes: a test voltage output device 300 and the aforementioned protection device 100, wherein the test voltage output device 300 is configured to provide a DC test voltage to the electrical device 200 under test; the protection device 100 is configured to protect the electrical device 200 under test during the process of the test voltage output device 300 performing a withstand voltage test on the electrical device 200 under test.

[0058] According to the withstand voltage test system of the embodiment of the present invention, the aforementioned protection device can protect the safety of the electrical equipment to be tested when the withstand voltage test system performs a withstand voltage test on the electrical equipment to be tested, thereby improving the safety of the withstand voltage test system.

[0059] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection portion with one or more wirings (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0060] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0061] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0062] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0063] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A protective device for voltage withstand testing of electrical equipment, characterized in that: include: A test connection unit, wherein the test connection unit is suitable for connecting the electrical device to be tested and the test voltage output device, so that a test loop is formed between the voltage input terminal of the electrical device to be tested and the output terminal of the test voltage output device; The protection unit is configured to block the test circuit when the test connection unit has poor contact, so as to protect the electrical device under test.

2. The protective device according to claim 1, characterized in that: The protection unit includes a first protection module, which is arranged between the positive output terminal of the test voltage output device and the positive input terminal of the electrical device under test, or the first protection module is arranged between the negative output terminal of the test voltage output device and the protection ground of the electrical device under test.

3. The protective device according to claim 2, characterized in that: The first protection module includes a first protection diode, wherein: In the case where the first protection module is arranged between the positive output terminal of the test voltage output device and the positive input terminal of the electrical device to be tested, the anode of the first protection diode is connected to the positive output terminal of the test voltage output device, and the cathode of the first protection diode is connected to the positive connection terminal in the test connection unit; When the first protection module is arranged between the negative output terminal of the test voltage output device and the protection ground of the electrical equipment under test, the cathode of the first protection diode is connected to the negative output terminal of the test voltage output device, and the anode of the first protection diode is connected to the protection ground of the electrical equipment under test.

4. The protection device according to claim 3, characterized in that: The first protection module also includes an absorption circuit, which is connected in parallel with the first protection diode to absorb the discharge impact current generated in the test loop.

5. The protection device according to claim 1, characterized in that: The protection unit includes a first protection module and a second protection module, wherein: The first protection module is arranged between the positive output terminal of the test voltage output device and the positive input terminal of the electrical device under test, and the second protection module is arranged between the positive output terminal of the test voltage output device and the negative input terminal of the electrical device under test; or The first protection module is arranged between the positive output terminal of the test voltage output device and the positive input terminal of the electrical device under test, and the second protection module is arranged between the negative output terminal of the test voltage output device and the protection ground of the electrical device under test.

6. The protection device according to claim 5, characterized in that: The first protection module includes a first protection diode, and the second protection module includes a second protection diode, wherein: In the case where the first protection module is arranged between the positive output terminal of the test voltage output device and the positive input terminal of the electrical device to be tested, and the second protection module is arranged between the positive output terminal of the test voltage output device and the negative input terminal of the electrical device to be tested, the anode of the first protection diode is connected to the positive output terminal of the test voltage output device, the cathode of the first protection diode is connected to the positive connection terminal in the test connection unit, the anode of the second protection diode is connected to the positive output terminal of the test voltage output device, and the cathode of the first protection diode is connected to the negative connection terminal in the test connection unit; When the first protection module is arranged between the positive output terminal of the test voltage output device and the positive input terminal of the electrical device under test, and the second protection module is arranged between the negative output terminal of the test voltage output device and the protection ground of the electrical device under test, the anode of the first protection diode is connected to the positive output terminal of the test voltage output device, the cathode of the first protection diode is connected to the positive connection terminal in the test connection unit, the cathode of the second protection diode is connected to the negative output terminal of the test voltage output device, and the anode of the first protection diode is connected to the protection ground of the electrical device under test.

7. The protection device according to claim 6, characterized in that: The first protection module and the second protection module further include an absorption circuit respectively, and the absorption circuit is connected in parallel with the corresponding protection diode to absorb the discharge impact current generated in the test loop.

8. The protection device according to claim 4 or 7, characterized in that: The absorption circuit includes an absorption resistor and an absorption capacitor connected in series.

9. The protective device according to any one of claims 1 to 7, characterized in that: It also includes a shorting switch, which is suitable for short-circuiting the positive input terminal and the negative input terminal of the electrical device under test when the electrical device under test is subjected to a withstand voltage test.

10. The protection device according to claim 1, characterized in that: The electrical equipment to be tested includes at least one of a motor controller, a photovoltaic inverter, an industrial inverter and a household appliance frequency converter.

11. A withstand voltage test system for electrical equipment, characterized in that: include: a test voltage output device configured to provide a DC test voltage to the electrical device under test; The protection device according to any one of claims 1 to 10 is configured to protect the electrical equipment under test during a process in which the test voltage output device performs a withstand voltage test on the electrical equipment under test.

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