CN-224231885-U - DC insulation monitoring device

CN224231885UCN 224231885 UCN224231885 UCN 224231885UCN-224231885-U

Abstract

The utility model discloses a direct current insulation monitoring device which comprises a monitoring host, a monitoring expansion module and a current transformer, wherein the monitoring host is in communication connection with a plurality of monitoring expansion modules, each monitoring expansion module is connected with a plurality of current transformers, the monitoring expansion module comprises an expansion control unit, an expansion communication unit, a current detection unit and a current reference unit, the expansion control unit is in communication connection with the monitoring host through the expansion communication unit, the expansion control unit is connected to the current detection unit, the expansion control unit is connected to the current reference unit, the current reference unit surrounds the current transformers, and the current detection unit surrounds the current transformers. The device can effectively improve the insulation monitoring performance of the insulation monitoring device, and is favorable for reducing the operation and maintenance frequency of operation and maintenance personnel on the insulation monitoring device. The utility model relates to the technical field of direct current power distribution.

Inventors

LI HONGBIN
YOU CHENXI
XU YUFENG
LI YONGXIANG
WU WENJIAN
YE FENGJIE

Assignees

广西电网有限责任公司防城港供电局

Dates

Publication Date: 20260512
Application Date: 20250115

Claims (10)

1. The direct current insulation monitoring device is characterized by comprising a monitoring host, a monitoring expansion module and a current transformer; the monitoring host is in communication connection with a plurality of monitoring expansion modules, and each monitoring expansion module is connected with a plurality of current transformers; The monitoring expansion module comprises an expansion control unit, an expansion communication unit, a current detection unit and a current reference unit; The expansion control unit is in communication connection with the monitoring host through the expansion communication unit, the expansion control unit is connected to the first end of the current detection unit, and the expansion control unit is connected to the first end of the current reference unit; The second end of the current reference unit is wound at the first end of the current transformer, and the second end of the current detection unit is wound at the second end of the current transformer.
2. The direct current insulation monitoring device according to claim 1, wherein the current reference unit comprises a first current reference circuit and a second current reference circuit; The first current reference circuit is positively surrounded at the first end of the current transformer, and the second current reference circuit is reversely surrounded at the first end of the current transformer.
3. The direct current insulation monitoring device according to claim 1, wherein the current detection unit comprises a first amplifier, an output end of the first amplifier being connected to the expansion control unit.
4. The direct current insulation monitoring device according to claim 1, wherein the monitoring host includes a host communication unit, a host control unit, a bridge circuit correction unit, and a voltage reference unit; The host control unit is in communication connection with the monitoring expansion module through the host communication unit; The host control unit is connected to the first end of the voltage reference unit, the host control unit is connected to the first end of the bridge circuit correction unit, and the second end of the voltage reference unit is connected to the second end of the bridge circuit correction unit.
5. The direct current insulation monitoring device according to claim 4, wherein the voltage reference unit comprises a sampling voltage stabilizing chip, a first resistor, a second resistor and a third resistor; The host control unit is connected to the first end of the sampling voltage stabilizing chip through the first resistor, the first end of the sampling voltage stabilizing chip is connected to the first end of the second resistor, and the second end of the sampling voltage stabilizing chip is connected to the first end of the second resistor; The third end of the sampling voltage stabilizing chip is connected to the second end of the third resistor, the first end of the third resistor is connected to the second end of the second resistor, and the first end of the third resistor is connected to the bridge circuit correction unit.
6. The direct current insulation monitoring device according to claim 4, wherein the bridge circuit correction unit comprises a bridge and voltage division circuit and a voltage amplification circuit; The input end of the bridge and the voltage dividing circuit is connected to a direct current bus in the direct current system, and the output end of the bridge and the voltage dividing circuit is connected to the voltage amplifying circuit.
7. The dc insulation monitoring device of claim 6, wherein the bridge and voltage divider circuit comprises a first switch, a second switch, a third switch, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, and an eleventh resistor; The first end of the first switch is grounded through the fourth resistor, the first end of the second switch is grounded through the fifth resistor, the first end of the third switch is grounded through the sixth resistor, and the first end of the fourth switch is grounded through the seventh resistor; The second end of the first switch is connected to the second end of the third switch, the second end of the third switch is connected to the first end of the eighth resistor, the second end of the eighth resistor is connected to the first end of the ninth resistor, the first end of the ninth resistor is connected to the first end of the voltage amplifying circuit, and the second end of the ninth resistor is grounded; The second end of the second switch is connected to the second end of the fourth switch, the second end of the fourth switch is connected to the second end of the eleventh resistor, the first end of the eleventh resistor is connected to the second end of the tenth resistor, the second end of the tenth resistor is connected to the second end of the voltage amplifying circuit, and the first end of the tenth resistor is grounded.
8. The direct current insulation monitoring device according to claim 6, wherein the voltage amplifying circuit comprises an optocoupler isolation chip and a second amplifier, an output end of the optocoupler isolation chip is connected to an input end of the second amplifier, and an output end of the second amplifier is connected to the host control unit.
9. The direct current insulation monitoring device of claim 4, wherein the monitoring host further comprises a display unit, the display unit being communicatively coupled to the monitoring host.
10. The direct current insulation monitoring device according to claim 4, wherein the monitoring host further comprises an alarm unit, the alarm unit being connected to the monitoring host.

Description

DC insulation monitoring device Technical Field The utility model relates to the technical field of direct current power distribution, in particular to a direct current insulation monitoring device. Background The direct current system is a power supply device which is applied to hydraulic power plants, thermal power plants, various substations and other users using direct current equipment and is used for providing direct current power for signal equipment, protection, automatic devices, accident lighting, emergency power supply and breaker opening and closing operation. In order to ensure high-quality operation of the direct current system, the power production unit needs to regularly overhaul and maintain the direct current system equipment. At present, the insulation state of the direct current system is usually monitored through the insulation monitoring device in the prior art, but because internal electronic components of the insulation monitoring device may be worn or aged due to environmental factors (such as temperature, humidity and the like) in long-term operation, the insulation monitoring performance of the insulation monitoring device is reduced, so that the operation and maintenance frequency of operation and maintenance personnel on the insulation monitoring device is increased. Accordingly, there is a need for solving and optimizing the problems associated with the prior art. Disclosure of utility model The utility model aims to solve the technical problems existing in the related technology to a certain extent. Therefore, an object of the embodiments of the present utility model is to provide a dc insulation monitoring device, where the device can effectively improve insulation monitoring performance of the insulation monitoring device, and is beneficial to reducing operation frequency of operation staff on the insulation monitoring device. In order to achieve the technical purpose, the embodiment of the utility model provides a direct current insulation monitoring device, which comprises a monitoring host, a monitoring expansion module and a current transformer; the monitoring host is in communication connection with a plurality of monitoring expansion modules, and each monitoring expansion module is connected with a plurality of current transformers; The monitoring expansion module comprises an expansion control unit, an expansion communication unit, a current detection unit and a current reference unit; The expansion control unit is in communication connection with the monitoring host through the expansion communication unit, the expansion control unit is connected to the first end of the current detection unit, and the expansion control unit is connected to the first end of the current reference unit; The second end of the current reference unit is wound at the first end of the current transformer, and the second end of the current detection unit is wound at the second end of the current transformer. In addition, the direct current insulation monitoring device according to the embodiment of the utility model can also have the following additional technical characteristics: Optionally, in one embodiment of the present utility model, the current reference unit includes a first current reference circuit and a second current reference circuit; The first current reference circuit is positively surrounded at the first end of the current transformer, and the second current reference circuit is reversely surrounded at the first end of the current transformer. Optionally, in one embodiment of the present utility model, the current detection unit includes a first amplifier, and an output terminal of the first amplifier is connected to the expansion control unit. Optionally, in one embodiment of the present utility model, the monitoring host includes a host communication unit, a host control unit, a bridge circuit correction unit, and a voltage reference unit; The host control unit is in communication connection with the monitoring expansion module through the host communication unit; The host control unit is connected to the first end of the voltage reference unit, the host control unit is connected to the first end of the bridge circuit correction unit, and the second end of the voltage reference unit is connected to the second end of the bridge circuit correction unit. Optionally, in one embodiment of the present utility model, the voltage reference unit includes a sampling voltage stabilizing chip, a first resistor, a second resistor, and a third resistor; The host control unit is connected to the first end of the sampling voltage stabilizing chip through the first resistor, the first end of the sampling voltage stabilizing chip is connected to the first end of the second resistor, and the second end of the sampling voltage stabilizing chip is connected to the first end of the second resistor; The third end of the sampling voltage stabilizing chip is connected to the second end of the third