Predictive power control strategy without grid voltage sensors of the Vienna rectifier

Abstract

This paper proposes a predictive power control strategy for the three-phase, six-switch Vienna rectifier without grid voltage sensors to reduce the hardware cost and complexity of a high-power PWM rectifier system. Firstly, an algorithm for calculating the AC-side voltage in the αβ coordinate system is derived according to the operating principle of the Vienna rectifier, and a voltage observer is constructed by combining a second-order low-pass filter to estimate the grid voltage. Secondly, a soft start method is designed to solve the problem that the rectifier is prone to inrush current when it is started. Furthermore, the control method of grid voltage sensorless is combined with predictive power control with good dynamic characteristics and simple parameter settings to form the control strategy proposed in this paper. Finally, simulation analysis and experimental verification are carried out on the proposed control strategy. Simulation and experimental results show that the grid voltage estimation has high accuracy, a good surge current suppression effect, unit power factor operation, low input current harmonic content, and good dynamic and steady-state performance. Therefore, the correctness and effectiveness of the strategy proposed in this paper are verified.