Suppression of parallel resonance and mitigation of harmonic distortion through shunt active power compensation

• Proposed solution to parallel resonance in shunt Active Power Filter compensation.
• The proposed solution turns the scheme of compensation into a Shunt Hybrid Filter.
• A Linear Quadratic Regulator-based switching controller was designed.
• Reduces the necessary KVA rating of the Active Power Filter (APF).
• Results obtained with Matlab/Simulink® illustrate the effective APF compensation.

In this contribution a solution to the parallel resonance problem that can be present in practical applications of shunt Active Power Filter (APF) compensation is proposed. The proposed solution involves turning the shunt APF scheme of compensation into a Shunt Hybrid Filter (SHF) configuration. A Linear Quadratic Regulator (LQR)-based switching controller was specifically designed for this hybrid scheme of compensation, maintaining stringent performance requirements on the tracking of filtering currents and the draining of the harmonic ripple currents. Results obtained with Matlab/Simulink® illustrate an effective and sound system of compensation which also reduces the necessary KVA rating of the APF.