Comparative Studies on Design Methods for Detuned C-Type Filter

Configuring a shunt capacitor as a detuned C-type filter is an effective way to mitigate the capacitor caused harmonic resonance. A design method has been developed recently that can guarantee the damping performance of the filter even if the system impedance data is not available. This article further improves the design method by considering the case where the system impedance data is available. It also answers the question if cost can be reduced by utilizing known system impedance data. For this purpose, the cost and power loss characteristics of the filter are investigated and included in the design. The performance of various design methods is compared from the perspectives of resonance-mitigation, power loss, cost, and robustness. The results have shown that the system independent design leads to superior performance except for the power loss. A guide on how to design the detuned C-type filter is recommended.