In the power system, ferroresonance occurs frequently, which will produce over-voltage and threaten the security of the system. Smr-wx series micro-computer harmonic elimination device developed by SMER Electric is simple and convenient to use, does not need maintenance, and can quickly eliminate ferromagnetic resonance of various frequencies, with high accuracy.

Smr-wx series micro-computer harmonic elimination is applicable to the small current power supply system with ungrounded neutral point or grounded through arc suppression coil under the voltage level of 66kV. At the same time, the relevant information is transmitted to the superior monitoring system through the communication interface, which is suitable for unattended substation.

Causes of ferroresonance:

1. There are system conflicts caused by line grounding, disconnection, asynchronous closing of circuit breaker, etc.

2. Resonance is excited by switching and closing the air bus or system disturbance.

3. Under some special operation mode, the system parameters match and reach the resonance condition.

Power system is a complex power network. In this complex power network, there are many inductance and capacitance components, especially in the ungrounded neutral system, ferromagnetic resonance often occurs, which brings hidden danger to the safe operation of equipment.

Ferromagnetic resonance can be fundamental resonance, high-order resonance, or sub harmonic resonance, and its manifestation may be single-phase, two-phase or three-phase to ground voltage rise, or low-frequency swing, causing insulation flashover or lightning arrester explosion, or high-value zero sequence voltage component, false grounding and incorrect grounding indication, or over-current in voltage transformer, causing The over-current in the fuse may cause the fuse to fuse or the mutual inductor to burn, or even cause the small capacity asynchronous motor to reverse.