AC-into-DC-system detection and forced tripping device

Abstract

The invention relates to an AC-into-DC-system detection and forced tripping device. The AC-into-DC-system detection and forced tripping device is characterized in that a DC system positive pole bus (+KM) is connected with one input end of an AC signal transmitter through a first DC blocking capacitor (C1); a DC system negative pole bus (-KM) is connected with another input end of the AC signal transmitter through a second DC blocking capacitor (C2); the output end of the AC signal transmitter is connected with a microprocessor; the two ports of the microprocessor are connected with the control end of a first optical coupler (OP1) and the control end of a second optical coupler (OP2) respectively; the output end of the first optical coupler (OP1) is connected in series with a coil of a first contactor (S1); and the output end of the second optical coupler (OP2) is connected in series with a coil of a second contactor (S2). The AC-into-DC-system detection and forced tripping device can realize on-line and real-time detection of the AC-into-DC fault, and meanwhile, can enable an AC or DC switch on a loop where the AC is mixed to be tripped in a forced manner to isolate the fault branch.

Description

technical field [0001] The invention relates to a detection and forced tripping device for alternating current intruding into a direct current system. Background technique [0002] In the substation, the DC system provides DC power for control, signal, relay protection, automatic device and emergency lighting, etc. The stable and reliable operation of the DC power supply plays a very important role in the safety and stability of the power system. However, due to the wide coverage of the DC system and the complex environment, faults of AC intrusion into the DC system occur from time to time, which can cause serious accidents such as metallic grounding of the DC system, false alarms of monitoring devices, and misoperation of relay protection devices, which are extremely harmful. According to the "Eighteen Major Power Grid Anti-Accident Measures of the State Grid Corporation" [2012]: "5.1.1.18.3 Newly built or renovated substations, DC system insulation monitoring devices shoul...

AI Technical Summary

Problems solved by technology

[0003] At present, there are also some detection methods and equipment for the fault of AC intrusion into the DC system, which can test the amplitude of the AC intrusion and the specific fault circuit, but they all have a single function and can only detect and cannot be treated.