Cascaded controller for single-phase shunt active power filter and STATCOM

Reactive power and harmonic current compensation are considered as two important issues in the electrical power system since they have strong impact on real power loss, voltage stability, resonance and operation cost. This paper presents a simple, yet effective cascade controller which is analysed and implemented on a single-phase grid-connected H-bridge and multilevel U-cell inverters. The proposed controller is used for the single-phase STATCOM and shunt active power filter. The DC bus capacitor voltages are regulated with the proportional-integral (PI) controllers. The proportional resonant (PR) controller is used for AC current control. The cascade operation of the PI and the PR controllers generates the control signal for the sinusoidal pulse width modulation. The reactive power compensation and harmonic current elimination are carried out by using the fundamental component of the grid current. The performance of the controller is analysed and the results of simulation and experimental work are presented.