A Multiband Shunt Hybrid Active Filter with sensorless control

This paper proposes a multiband shunt hybrid active filter (SHAF) with sensorless control. The plant is modeled in the discrete- time domain and a controller is designed using Pole shifting law in the polynomial domain. This control approach is very useful for filtering the load harmonics with reduced sensor counts where low cost solution like SHAF. Multiple synchronous reference frames (MSRF) and low pass filters are used to measure 5^th and 7^th harmonic components separately from load as well as filter currents. Individual current controllers are designed for the 5^th and 7^th harmonic currents. Control is realized in the stationary, three-phase (abc) reference frame. Performance of the controller is validated through simulation, using realistic plant and controller models, as well as experimentally on a full-scale distribution system.