Cross-current prevention device during parallel operation of power conversion device and control method thereof

摘要

PROBLEM TO BE SOLVED: To eliminate a risk of reducing the effective value of an output voltage command during the parallel operation of power conversion devices if cross current prevention control means is provided.SOLUTION: A cross current compensation limit calculation unit is provided between a current control unit and a PWM control unit, and a cross current compensation limit processing unit is provided between a cross current control unit and the PWM control unit. The cross current compensation limit calculation unit calculates difference between a voltage command and an upper limit value of a triangular wave carrier, and difference between the voltage command and a lower limit value of the carrier, and outputs them to the cross current compensation limit processing unit. The cross current compensation limit processing unit inputs a cross current compensation value from the cross current control unit, and outputs the upper limit value of the carrier as the upper limit value of the cross current compensation limit, and the lower limit value of the carrier as the lower limit vale of the cross current compensation limit.SELECTED DRAWING: Figure 1