Abstract: The control system design of the Vienna rectifier is inseparable from the parameters of grid voltage. However, conventional voltage sensors increase the cost and complexity of the system. Therefore, a model predictive control strategy for the Vienna rectifier without a grid voltage sensor is proposed in this paper. First, the mathematical model of virtual flux for the Vienna rectifier was established to estimate the power grid voltage. A second-order low-pass filter was adopted to eliminate the initial integral value and DC bias problem, which in turn improved the observation effect. Secondly, combined with the direct power mode predictive control(DPMPC),the switching sequence of the three-bridge arm was obtained to minimize the power tracking error. The results show that the proposed control strategy has low harmonic content. The voltage can accurately track the given value. It has good steady-state and dynamic performance.

Key words: Vienna rectifier, model predictive direct power control, grid voltage-sensorless, virtual flux, sliding mode control