Space phasor based improved hysteresis current controller for shunt active power filter using 3-level inverter

In this paper an improved control method is proposed for space phasor based Hysteresis Current Controller. For medium voltage application, Shunt Active Power Filter (SAPF) using this improved controller will be able to meet the strict power quality standards. In a grid connected system, nonlinear loads using semiconductor devices pose a serious threat to power quality and there this proposed controller due to its fast current tracking ability, can be a suitable choice. All the inherent advantages of space phasor based approach remains intact in it including optimal voltage phasor switching. A simple approach to compute online current error boundary similar to that of a 2-level Voltage Source Inverter (VSI), is applied to a 3-level structure here. Finally, a grid connected Diode Bridge Rectified (DBR) load and a 3-level SAPF system is simulated in desktop to validate all the features of the proposed controller.