An improved control strategy for a 50-kHz auxiliary resonant commutated pole converter

The auxiliary resonant commutated pole (ARCP) has been suggested as one means of reducing switching losses in high-power DC/AC converter applications through zero-voltage switching. A three-phase, 50-kHz inverter based on the ARCP topology has been implemented for use in an electric power distribution system testbed as part of the Office of Naval Research Power Electronic Building Block initiative. Experience gained in designing and testing the individual converters to be used in this system has revealed several interesting control issues when using the converters as motor or actuator drives. In particular, it can be shown that the basic control strategy for the ARCP may not accomodate sustained unipolar currents common at start-up of motors with high inertial loads or in actuator applications. Problems arising from ramping of the DC bus voltage are discussed. An improved control strategy that can accommodate these operating conditions is then described. Simulation and experimental results are used to demonstrate the effectiveness of the new strategy