Estimation method of unbalanced power grid voltage in PWM Rectifier control system

摘要

To achieve the self-sensing detection of unbalanced power grid voltage, control system under the unbalanced power grid conditions are analyzed. Then the positive and negative sequence virtual flux of power grid is separated; then an estimation algorithm of unbalanced power grid voltage is presented by the positive and negative sequence virtual flux components. In addition, the unbalanced power grid voltage sensorless control system is constructed. The simulation results show that the accurate self-sensing detection of unbalanced power grid voltage can be realized; and in the steady state, a high stability can be obtained in the DC side voltage of PWM rectifier.