A predictive estimation based control strategy for a quasi-resonant dc-link inverter

Control of parallel quasi resonant dc link inverters (PQRDCLI) is usually based on dc link input inverter current. Instead of a direct measurement of this noise sensitive and fast changing current signal - its estimation with one step prediction may be considered. Estimation of an input inverter current is based on inverter output current measurements, applied in most of power electronics controlled ac drives. In this paper, the PQRDCLI fed induction motor (IM) with a predictive current estimation stabilizes resonant inverter output voltage slopes du/dt independently of load. By control of output voltage derivatives, reduction of overvoltage spikes and common mode motor currents is achieved. An analysis of the PQRDCLI control with a predictive current estimation strategy is verified by the Saber system simulation and experimental tests in a laboratory setup.