OPTIMAL SYNCHRONOUS PULSEWIDTH MODULATION WITH A TRAJECTORY-TRACKING SCHEME FOR HIGH-DYNAMIC PERFORMANCE

Synchronous pulsewidth modulation based on precalculated and stored op timal pulse patterns could be a superior method for the control of hig h-power inverters operated at low switching frequency. The technique h as rarely been applied in practice owing to its poor dynamic performan ce. A novel feedforward control technique eliminates this decisive dra wback: the space vector of the machine currents is forced to track a p recalculated optimal trajectory in the steady-state and under the tran sient operating conditions commanded by the drive control system. Unde sired transients caused by the pulsewidth modulator are avoided. Exper imental results obtained from a 30-kW ac drive are presented,