Coupler for insulation detection of high-voltage motor

Abstract

The utility model relates to the technical field of motor detection equipment, in particular to a coupler for insulation detection of a high-voltage motor, which comprises a shell, an elbow-shaped joint and a PCB (printed circuit board), a high-voltage fuse, a first power resistor, two relay groups and a power resistor module are arranged in the PCB, each relay group consists of two relays, each relay comprises a control end and an output end, and the power resistor module is connected with the elbow-shaped joint. The control ends of the two relays in the same group are connected in series, the control ends of the two relay groups are connected in parallel to form an HC1 end and an HC2 end, the elbow-shaped connector, the high-voltage fuse, the output ends of the relays and the power resistor module are connected in series to form an HV end and an AK1 end, and the high-voltage motor is safely connected only through one elbow-shaped connector. And connection with an insulation instrument is simple, and only two aviation plugs are used for connection. On-site construction and safety requirements are met, and when the coupler breaks down, namely a fuse or an internal element is damaged, self-diagnosis can be carried out through an insulation instrument to remove the fault.

Description

Technical Field

[0001] This utility model relates to the technical field of motor testing equipment, specifically a coupler for high-voltage motor insulation testing. Background Technology

[0002] Insulation resistance testing involves measuring the insulation resistance of a motor using a ohmmeter. However, testing the insulation resistance of a high-voltage motor requires both an insulation meter and a high-voltage generator. While a dedicated insulation resistance tester is typically used, a coupler is required when connecting the insulation meter to the high-voltage line of the high-voltage motor.

[0003] When using couplers to connect to the high-voltage lines of high-voltage motors, each phase needs to be connected. This connection method is complex, and high-voltage cabinets generally have limited space, making installation difficult and posing a creepage distance hazard. Furthermore, when a coupler malfunctions—i.e., a fuse or internal component fails—it cannot be self-diagnosed and troubleshooted using insulation instruments. Therefore, there is an urgent need to develop a coupler for high-voltage motor insulation detection to meet practical application requirements. Utility Model Content

[0004] The purpose of this invention is to provide a coupler for high-voltage motor insulation detection to address the aforementioned deficiencies.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A coupler for high-voltage motor insulation detection includes a housing, an elbow joint, and a PCB board. The PCB board contains a high-voltage fuse, a first power resistor, two sets of relay groups, and a power resistor module. Each set of relay groups consists of two relays, and each relay includes a control terminal and an output terminal. The control terminals of the two relays in the same group are connected in series, and the control terminals of the two sets of relay groups are connected in parallel to form HC1 and HC2 terminals. The elbow joint, the high-voltage fuse, the output terminals of the relays, and the power resistor module are connected in series to form HV and AK1 terminals.

[0007] The rated AC voltage of the high-voltage fuse is 10 kV, and the rated current is 0.5 A.

[0008] The rated resistance of the first power resistor is 200 megohms, and the rated power of the first power resistor is 90 watts.

[0009] As a further embodiment of the above description, the total power of the power resistor module is 90W. The power resistor module consists of several second power resistors and one third power resistor. Both the second and third power resistors are metal film resistors of type MF. The several second power resistors and the third power resistor are connected in series.

[0010] As a further embodiment of the above description, the number of second power resistors is twenty-nine, the rated resistance of the second power resistors is 330 kΩ, and the rated resistance of the third power resistors is 430 kΩ.

[0011] As a further embodiment of the above description, the surface of the housing is provided with several aviation plugs, with AK1, HC1 and HC2 terminals respectively located at the aviation plugs for connection to external insulated instruments.

[0012] The beneficial effects of this utility model are as follows:

[0013] This application discloses a coupler for high-voltage motor insulation testing. On one hand, the coupler features comprehensive internal protection components and a compact overall structure, with most components integrated into a single housing and protected by epoxy resin. Connection to the high-voltage motor is secure via a single elbow connector, and connection to insulation instruments is simple, requiring only two aviation plugs. This facilitates on-site installation and meets safety requirements.

[0014] On the other hand, when the coupler malfunctions, i.e. when the fuse or internal components are damaged, the fault can be eliminated through self-diagnosis using an insulating instrument. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the circuit principle of the coupler for high-voltage motor insulation detection described in this utility model;

[0016] Figure 2 This is a PCB design drawing of a coupler for high-voltage motor insulation detection according to the present invention;

[0017] In the diagram: 3-high voltage fuse, 4-first power resistor, 5-relay group, 51-relay, 6-power resistor module, 61-second power resistor, 62-third power resistor, 8-PCB board. Detailed Implementation

[0018] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention. The present invention will be described in detail below with reference to the accompanying drawings.

[0019] Please see Figure 1-2The specific implementation of the coupler for high-voltage motor insulation detection includes a housing, an elbow joint, and a PCB board 8. The PCB board 8 contains a high-voltage fuse 3, a first power resistor 4, two sets of relay groups 5, and a power resistor module 6. Each of the two sets of relay groups 5 consists of two relays 51. Each relay 51 includes a control terminal and an output terminal. The control terminals of the two relays 51 in the same group are connected in series, and the control terminals of the two sets of relay groups 5 are connected in parallel to form HC1 and HC2 terminals. The elbow joint, the high-voltage fuse 3, the output terminals of the relays 51, and the power resistor module 6 are connected in series to form HV and AK1 terminals. The elbow joint is connected to the side of the high-voltage fuse 3 away from the output terminal of the relay 51 via a high-voltage cable. The elbow joint is used to connect one phase of an external high-voltage motor.

[0020] The rated AC voltage of high-voltage fuse 3 is 10 kV, and the rated current is 0.5 A.

[0021] The rated resistance of the first power resistor 4 is 200 megohms, and the rated power of the first power resistor 4 is 90 watts.

[0022] The total power of the power resistor module 6 is 90W. The power resistor module 6 consists of twenty-nine second power resistors 61 and one third power resistor 62. Both the second power resistors 61 and the third power resistor 62 are metal film resistors of type MF. The twenty-nine second power resistors 61 and the third power resistor 62 are connected in series. The rated resistance of the second power resistor 61 is 330 kΩ and the rated resistance of the third power resistor 62 is 430 kΩ.

[0023] The housing has two aviation connectors on its surface. The AK1, HC1 and HC2 terminals are located at the aviation connectors and are used to connect to external insulated instruments.

[0024] Both the elbow connector and PCB board 8 are located inside the housing. The housing also contains an insulating epoxy layer, which fills and covers the surface of PCB board 8. The coupler has comprehensive internal protection components and a compact overall structure. Most components are integrated into a single housing and are isolated and protected by epoxy. In use, it is simply connected to one phase of the high-voltage motor via the elbow connector, making connection to the insulation instrument straightforward. The 2500VDC phase of the external insulation instrument is connected to AK1 for outputting electrical test signals; the 24VDC phase of the external insulation instrument is connected to terminals HC1 and HC2 respectively for outputting control signals for controlling the opening and closing of relay 51.

[0025] The detection process of a coupler for high-voltage motor insulation testing is as follows: When the high-voltage motor stops running, the insulation instrument sends a 24VDC control signal to terminals HC1 and HC2, which connects the four contacts K1, K2, K3, and K4 at the output terminals of the four relays 51. Simultaneously, the insulation instrument sends a 2500VDC measurement signal from terminal AK1, which is isolated and current-limited by the power resistor module 6, then passes through the contacts K1, K2, K3, and K4 of the four relays 51, 10KV, and the high-voltage fuse 3, and is output from terminal HV via an elbow joint. The measurement signal is then applied to the high-voltage motor to perform insulation resistance measurement. When the high-voltage motor is running, there is high voltage on the HV side, the insulation instrument is in a stopped measurement state, the control terminal contacts of the four vacuum relays 51 are open, there is no high voltage at terminal AK1, and it is safe for the insulation instrument.

[0026] When the high-voltage motor is running, the four high-voltage vacuum relays 51 output contacts K1, K2, K3, and K4 are incorrectly connected. The high voltage is then applied to the first power resistor 4 through the HV terminal. Because the first power resistor 4 has a high resistance of 10MΩ, it can divide and limit the high voltage at the HV terminal, resulting in only a very small current and voltage. This voltage is then applied to the 2500VDC terminal of the insulation instrument through the AK1 terminal, allowing the insulation instrument to operate safely.

[0027] A self-testing process for a coupler used for high-voltage motor insulation detection: When the high-voltage motor stops running, the grounding switch on one side of the motor is closed, activating the insulation resistance measurement function of the insulation instrument. If any of the four relays 51's output terminals K1, K2, K3, and K4 is not conducting, the insulation resistance measured by the insulation instrument will be infinite, thus indicating that relay 51 has failed. If the high-voltage fuse 3 is open-circuited, the insulation resistance measured by the insulation instrument will be 200MΩ, thus indicating that the high-voltage fuse has failed.

[0028] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the present utility model without departing from the scope of the present utility model shall fall within the scope of the present utility model.

Claims

1. A coupler for high voltage motor insulation detection comprising a housing, an elbow joint and a PCB board, characterized in that: The inside of the PCB board is provided with a high-voltage fuse, a first power resistor, two groups of relay groups and a power resistor module, each group of relay groups is composed of two relays, the relays include control ends and output ends, the control ends of the two relays in the same group are connected in series, the control ends between the two groups of relays are connected in parallel to form HC1 end and HC2 end, the elbow joint, the high-voltage fuse, the output ends of the relays and the power resistor module are connected in series to form HV end and AK1 end.

2. A coupler for high voltage electrical machine insulation detection according to claim 1, characterized in that: The total power of the power resistor module is 90W, the power resistor module is composed of a plurality of second power resistors and a third power resistor, the second power resistors and the third power resistor are both MF type metal film resistors, and the plurality of second power resistors and the third power resistor are connected in series.

3. A coupler for high voltage electrical machine insulation detection according to claim 2, characterized in that: The number of the second power resistors is twenty-nine, the rated resistance of the second power resistor is 330 kilo-ohms, and the rated resistance of the third power resistor is 430 kilo-ohms.

4. The coupler for high voltage machine insulation detection of claim 1, wherein: The surface of the shell is provided with a plurality of aviation plugs, the AK1 end, the HC1 end and the HC2 end are arranged at the aviation plugs, and are used for connecting with external insulation instruments.

5. A coupler for high voltage electrical machine insulation detection according to claim 1, characterized in that: The elbow joint is connected to the side away from the output end of the relay of the high-voltage cable and the high-voltage fuse, and the elbow joint is used for connecting one phase of an external high-voltage motor.

6. A coupler for high voltage electrical machine insulation testing according to any one of claims 1 to 5, characterized in that: The elbow joint and the PCB board are arranged in the inside of the shell, and the inside of the shell is further provided with an insulating epoxy layer, and the insulating epoxy layer fills and covers the surface of the PCB board.

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