In the power system, there will be a variety of fault phenomena, for example, the occurrence of ferromagnetic resonance phenomenon, there will be professional elimination of various frequencies of ferromagnetic resonance microcomputer harmonic elimination device, the occurrence of single-phase grounding fault, there will be small current grounding line selection device, which can accurately find the fault line.

The microcomputer harmonic eliminator is also a secondary harmonic eliminator, which is installed in the open delta winding of the voltage transformer. When the system is running normally or single-phase grounding occurs, the device will not act. Once the ferromagnetic resonance occurs in the power grid, the device will make the two thyristors connected in parallel at the two ends of the open triangle alternately cross zero to trigger conduction to eliminate the ferromagnetic resonance. When the resonance is eliminated, the thyristor will cut off automatically, and it can act repeatedly if necessary.

Compared with other harmonic elimination methods, microcomputer harmonic elimination device has more advantages

A distribution network system only needs to be equipped with a microcomputer for harmonic elimination;

The communication function with the substation monitoring system enables the device to have the characteristics of remote monitoring, and the operator can monitor the operation status of the power grid at any time;

The intelligent microcomputer harmonic elimination device has the function of storage and memory, which can record the electric quantity before and after the power grid fault and the change process of its state, completely reflect the action of the device, and facilitate the staff to analyze and deal with the accident.