Adaptive neural networks for AC voltage sensorless control of three-phase PWM rectifiers

Abstract

In this paper, a new adaptive grid voltages estimator for AC voltage sensorless control of three-phase pulse-width modulation (PWM) rectifier is proposed. This method is based on a simple adaptive neural network (ANN) to estimate online the grid voltages. Its main advantages are the simplicity and low computational cost requirements. The proposed ANN estimator is inserted in voltage-oriented control (VOC) to perform an AC voltage sensorless control scheme. As the start-up is a common problem in case of sensorless control, a new start-up process is also proposed for estimating initial values of the grid voltages. Experimental tests are carried out to verify the feasibility and robustness of the proposed ANN estimator. Obtained results show good performances of the proposed AC voltage sensorless control scheme in normal and severe grid voltage conditions.