Optimal synchronous pulsewidth modulation with a trajectory-tracking scheme for high-dynamic performance

Synchronous pulse-width modulation (PWM) based on precalculated and stored optimal pulse patterns could be a superior method for the control of high-power inverters operated at low switching frequency. The technique has rarely been applied in practice owing to its poor dynamic performance. A novel feedforward control technique eliminates this decisive drawback: the space vector of the machine currents is forced to track a precalculated optimal trajectory in the steady-state and under the transient operating conditions commanded by the drive control system. Undesired transients caused by the pulse-width modulator are avoided. Experimental results obtained from a 30 kW AC drive are presented