Adaptive Feed-Forward Cancellation Control of a Full-Bridge DC-AC Voltage Inverter

Dc-ac inverters are needed in many applications. The full-bridge dc-ac inverter has been widely used in industry applications and trough the literature. If the nature of the load is not known a priori, some considerations should be taken in order to assure the quality of service to be provided by the inverter. When nonlinear loads are fed by a full-bridge dc-ac inverter, odd harmonics of the fundamental ac frequency are introduced into the output voltage shape. For the purpose of producing a good sinusoidal output voltage signal, the control strategy must be able to reject periodic output disturbances. Adaptive Feed-forward Cancellation (AFC) is a control technique that has been successfully used to selectively reject periodic output disturbances in continuous-time mechanical systems. This paper deals with the use of AFC to control the output voltage of an electrical system, in this case, a dc-ac full-bridge inverter, to produce a standard European ac voltage signal, 230 Vrms and 50 Hz, accomplishing the design of the controller directly in the z-domain.