CONTROL METHOD FOR POWER CONVERTER FOR PARALLEL OPERATION, POWER CONVERTER FOR PARALLEL OPERATION, AND PARALLEL OPERATION POWER CONVERSION SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a control method for a power converter for parallel operation that is operated in parallel with an external power converter by a three-phase voltage instruction, the control method reducing a circulating current flowing between power converters without using a special apparatus.SOLUTION: The control method has: a first two-arm control step of fixing a switching operation in one phase out of three phases and carrying out PWM control in the other two phases; a three-arm control step of carrying out PWM control for a given time in three phases following the first two-arm control step; and a second two-arm control step of fixing a switching operation in a phase different from the phase in which the switching operation is fixed at the first two-arm control step and carrying out PWM control in the other two phases after the three-arm control step.