Unit-delay deadbeat control of a high bandwidth active power filter

grantor: University of TorontoThis thesis presents a novel unit-delay digital deadbeat current controller for a shunt active power filter (APF) based on a voltage-sourced converter (VSC). This current controller architecture increases the APF current-tracking bandwidth without increasing the VSC switching frequency. Previous APF deadbeat controllers are implemented in high-performance digital signal processors (DSP), but demonstrate a current-tracking delay of two sample periods. One sample period delay is due to current controller computation time. The second sample period delay represents VSC actuation time. In the proposed scheme, the current-tracking feedback control calculations are executed in programmable digital logic. Economical asynchronous arithmetic circuitry effectively eliminates computation delay, resulting in unit-delay reference tracking. A low-cost microprocessor provides fundamental frequency feed-forward disturbance rejection, as well as other supervisory functions. Experimental results from a laboratory implementation verify the desired operation of the APF current control system.M.A.Sc