DSP - Based Control Strategies for An Inverter - Based Compensator

The focus of this thesis is on the study and experimental implementation of a voltage source inverter-based reactive power compensator. A general mathematical model of the system has been developed, fiom which a approximate linearized model is derived. The approximate model introduces a simple means of characterizing the fundamental fiequency behaviour of the compensator. This pennits the characterization of the stationary and dynamic behaviour of the compensator in ternis of the system parameters and the switching scheme used. The experimental results have verified that this approximate model represents very wel1 the fundamental fiequency behaviour of the system over the operating range of interest. Feedforward and feedback control on the dc bus voltage are also investigated. Piecewise linearization of the cornpensator's stationary response proved to be a good solution in overcohg the deviation fiom the desired values in feedforward control. Feedback control not only reduced the steady-state errors, but also improved the dynamic performance of the compensation system. It is demonstrated that the laboratory prototype behaves satisfactorily under stationary and dynamic conditions. Fuahermore, details of the system hardware and software are described Theoretical and experimental results conceniing the solvability of hannonic elimination schemes are also presented. Master Thesis: DSP-Based Conml Stategies for An Inverter-Based Compensator