WZJ-21 DC Insulation Detector:DC Insulation Detector plays an important role in DC system. The operation practice has proved that the harm of DC system grounding not only causes the relay protection device to be misoperated and failed to operate, but even causes the primary equipment to be misoperated and failed to operate, which seriously endangers the safe and stable operation of the power system. Therefore, it is necessary to monitor the insulation status of the DC system to the ground in real time, and troubleshoot the fault in time when grounding occurs.

Combined with WZJ - 11 series microcomputer DC Insulation Detector in power system operation experience for many years, has developed WZJ- 21 microcomputer DC Insulation Detector (hereinafter referred to as WZJ-21), it can real-time online monitoring of the DC bus and the insulation condition, can quickly find and determine when a dc grounding bus bar or branch, and issued a warning signal; Insulation alarm information can also be uploaded to the top computer through RS485 communication. The WZJ-21 device adopts the principle of the combination of balanced bridge and unbalanced bridge to detect the insulation state of the bus to the ground. It does not inject signals into the DC system and is not affected by the capacitance of the DC feeder to the ground. The device can be used in power plants, substations and other places to use a variety of complex DC systems.