Online insulation monitoring system for ITN / IT power supply system

Abstract

The utility model provides an ITN / IT power supply system on-line insulation monitoring system comprising a three-phase four-wire input line with a three-phase four-wire input end, and the three-phase four-wire input line comprises an A phase, a B phase, a C phase and an N phase; a first resistor module is arranged at the A phase, and the A phase is connected with a wiring terminal through the first resistor module; a second resistor module is arranged at the B phase, and the B phase is connected with a wiring terminal through the second resistor module; a third resistor module is arranged at the C phase, and the C phase is connected with a wiring terminal through the third resistor module; and a fourth resistor module is arranged at the N phase, and the N phase is connected with a wiring terminal through the fourth resistor module. According to the utility model, the circuit structure of the injection resistor part is redesigned, so that the problem of heating when the resistor becomes a load through on-line injection and neutral line injection when the neutral line is not led out is solved.

Description

Technical Field

[0001] This utility model relates to a monitoring device used in power transmission and distribution systems, specifically a wiring device for injecting an online signal source for ITN insulation monitoring. Background Technology

[0002] Current IT N The signal injection method of the online insulation monitoring device of the IT power supply system is to inject a monitoring signal between the N line and the ground line. However, when the transformer does not have a neutral line, it is impossible to inject a signal between the neutral line and the ground line. Only the three-phase line injection method can be adopted. Line injection is equivalent to adding a 380V power supply to the original injection device resistor, making the resistor a load and generating a lot of heat, which poses a heat dissipation problem.

[0003] Existing solutions involve increasing the resistor power, but the existing devices have limited space and require internal rewiring for line injection and neutral line injection. Therefore, it is necessary to redesign the circuitry of the existing injection source resistor section. Utility Model Content

[0004] The technical problem to be solved by this invention is to redesign the circuit structure of the injected resistor section to address the heat generation issue when the resistor becomes a load after being injected through the line and the neutral line without leading out the neutral line.

[0005] This utility model provides an IT N A wiring device for injecting online signal sources for online insulation monitoring in an IT power supply system includes a three-phase four-wire input line with three-phase four-wire input terminals. The three-phase four-wire input line includes phase A, phase B, phase C, and phase N. A first resistor module is installed in phase A, and phase A is connected to a terminal block via the first resistor module. A second resistor module is installed in phase B, and phase B is connected to a terminal block via the second resistor module. A third resistor module is installed in phase C, and phase C is connected to a terminal block via the third resistor module. A fourth resistor module is installed in phase N, and phase N is connected to a terminal block via the fourth resistor module.

[0006] Each of the first resistor module, the second resistor module, the third resistor module, and the fourth resistor module contains at least two resistors.

[0007] Preferably, the first resistor module, the second resistor module, the third resistor module, and the fourth resistor module each contain three resistors.

[0008] More preferably, the three resistors are connected in parallel.

[0009] More preferably, the three resistors are connected in series.

[0010] More preferably, the two resistors are connected in parallel and in series with the remaining resistor.

[0011] More preferably, the two resistors are connected in series and in parallel with the remaining resistor.

[0012] Preferably, the resistance value of the resistor is between 1 ohm and 100k ohms.

[0013] Preferably, the power of the resistor is 5 watts.

[0014] This utility model also provides an IT N / IT power supply system online insulation monitoring system, applying the aforementioned IT N Wiring device for online insulation monitoring and online signal source injection in IT power supply systems.

[0015] Preferably, the transformer in the monitoring system does not have a neutral line.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows: Based on the current voltage levels of low-voltage power supply systems, which are mainly 690V and 400V, this utility model selects resistors of 1-100K and 2-5W, and reserves n resistors for each item (n is matched according to the number of selected resistors). The two ends of the resistors are respectively introduced into the wiring terminals. In this way, the wiring method can be selected according to the line injection or neutral point injection. At the same time, the series and parallel connection of the first and last terminals of the resistors can be selected according to the voltage level of the power supply system. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the wiring device layout structure of this utility model;

[0018] Figure 2 This is a schematic diagram of the parallel structure of the wiring device of this utility model;

[0019] Figure 3 This is a schematic diagram of the series connection structure of the wiring device of this utility model. Detailed Implementation

[0020] The online monitoring device and detection method for DC injection insulation performance of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Example 1

[0021] See Figure 1 and Figure 2 This embodiment provides an IT NA wiring device for injecting online signal sources for online insulation monitoring in IT power supply systems includes a three-phase four-wire input line with three-phase four-wire input terminals, comprising phase A, phase B, phase C, and phase N. A first resistor module is installed in phase A, and phase A is connected to a terminal block via the first resistor module. A second resistor module is installed in phase B, and phase B is connected to a terminal block via the second resistor module. A third resistor module is installed in phase C, and phase C is connected to a terminal block via the third resistor module. A fourth resistor module is installed in phase N, and phase N is connected to a terminal block via the fourth resistor module.

[0022] In this embodiment, the first resistor module, the second resistor module, the third resistor module, and the fourth resistor module each contain three resistors.

[0023] In this embodiment, the three resistors in each of the first, second, third, and fourth resistor modules are connected in series. The resistance value of each resistor is selected from 1 ohm to 100k ohms, and the power rating of each resistor is 5 watts.

[0024] By using a series connection, the resistance is increased to accommodate higher voltage inputs. Example 2

[0025] See Figure 1 and Figure 3 This embodiment provides an IT N A wiring device for injecting online signal sources for online insulation monitoring in IT power supply systems includes a three-phase four-wire input line with three-phase four-wire input terminals, comprising phase A, phase B, phase C, and phase N. A first resistor module is installed in phase A, and phase A is connected to a terminal block via the first resistor module. A second resistor module is installed in phase B, and phase B is connected to a terminal block via the second resistor module. A third resistor module is installed in phase C, and phase C is connected to a terminal block via the third resistor module. A fourth resistor module is installed in phase N, and phase N is connected to a terminal block via the fourth resistor module.

[0026] In this embodiment, the first resistor module, the second resistor module, the third resistor module, and the fourth resistor module each contain three resistors.

[0027] In this embodiment, the three resistors in each of the first, second, third, and fourth resistor modules are connected in parallel. The resistance value of each resistor is selected from 1 ohm to 100k ohms, and the power rating of each resistor is 5 watts.

[0028] By using a parallel connection, the resistance is increased to accommodate lower voltages. Example 3

[0029] This embodiment is a variation of embodiment 1 or 2. In this case, the connection method between the three resistors in each of the first resistor module, the second resistor module, the third resistor module, and the fourth resistor module is such that two of the resistors are connected in parallel and connected in series with the remaining resistor. Example 4

[0030] This embodiment is a variation of embodiment 1 or 2. In this case, the connection method between the three resistors in each of the first resistor module, the second resistor module, the third resistor module, and the fourth resistor module is such that two of the resistors are connected in series and in parallel with the remaining resistor. Example 5

[0031] This embodiment provides an online insulation monitoring system for an ITN / IT power supply system, which uses any one of the wiring devices in Embodiments 1 to 4.

[0032] In this monitoring system, the transformer does not have a neutral line.

[0033] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it; although referring to the foregoing embodiments

[0034] The present invention has been described in detail. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An online insulation monitoring system for ITN / IT power supply systems, characterized in that: The device includes a wiring device for injecting online signal sources for online insulation monitoring in ITN / IT power supply systems. The wiring device includes a three-phase four-wire input line with three-phase four-wire input terminals, wherein the three-phase four-wire input line includes phase A, phase B, phase C, and phase N. A phase is provided with a first resistor module, and the A phase is connected to the terminal block through the first resistor module; A second resistor module is provided in phase B, and phase B is connected to the terminal block through the second resistor module. A third resistor module is provided in the C phase, and the C phase is connected to the terminal block through the third resistor module; The N phase is equipped with a fourth resistor module, and the N phase is connected to the terminal block through the fourth resistor module; Each of the first resistor module, the second resistor module, the third resistor module, and the fourth resistor module contains at least two resistors.

2. The online insulation monitoring system for ITN / IT power supply system as described in claim 1, characterized in that: The first resistor module, the second resistor module, the third resistor module, and the fourth resistor module each contain three resistors.

3. The online insulation monitoring system for ITN / IT power supply system as described in claim 2, characterized in that: The three resistors are connected in parallel.

4. The online insulation monitoring system for ITN / IT power supply system as described in claim 2, characterized in that: The three resistors are connected in series.

5. The online insulation monitoring system for ITN / IT power supply system as described in claim 2, characterized in that: The two resistors are connected in parallel and in series with the remaining resistor.

6. The online insulation monitoring system for ITN / IT power supply system as described in claim 2, characterized in that: The two resistors are connected in series, and in parallel with the remaining resistor.

7. The online insulation monitoring system for ITN / IT power supply system as described in claim 1, characterized in that: The resistance value of the resistor is between 1 ohm and 100k ohms.

8. The online insulation monitoring system for ITN / IT power supply system as described in claim 1, characterized in that: The resistor has a power rating of 5 watts.

9. The online insulation monitoring system for ITN / IT power supply system as described in claim 1, characterized in that: The transformer in the monitoring system does not have a neutral line.

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