Three Tuned Passive Filter to Improve Power Quality

With analyzing the traditional characteristics of double tuned filter, a novel three-tuned filter for power system is proposed in the paper. The filter is equivalent to three single tuned filters. The algorithm for determining the filter´s parameters is presented. A three-tuned filter for a 110 kV power grid is designed, simulated and tested. The results show that the filter can filter three different given frequency harmonics, and it has better performance than three single-tuned filters in filtering harmonics, low power loss, low space occupation, low price, only one reactor subjected to power line-power voltage and one switchgear needed.