CONTROL METHOD FOR POWER CONVERTING DEVICE, UNINTERRUPTIBLE POWER SUPPLY DEVICE, AND PARALLEL INSTANTANEOUS-VOLTAGE-DROP COMPENSATION DEVICE

摘要

PROBLEM TO BE SOLVED: To execute stable control when a higher harmonic is superposed on a load current or even when a detection delay of the load current or a calculation delay of a current command value occurs while eliminating adjustment of V-Q characteristics and F-P characteristics.

SOLUTION: PI calculation is executed by subtracting an active current and a reactive current in each output current Iout_1-Iout_n of each system from an active-current command value A1 for one inverter and a reactive-current command value A2 for one inverter respectively calculated from a load current IL. A value obtained by subjecting the active current component to the PI calculation is multiplied by a unit waveform of a SIN wave synchronized with each inverter output voltage Iout_1-Iout_n. A value obtained by subjecting the reactive current component to the PI calculation is multiplied by a unit waveform of a COS wave obtained by shifting the inverter output voltage by 90 degrees. The active current component and the reactive current component are added so as to calculate a correction amount B for each system that compensates an unbalance current between the inverters. The correction amount B for each system is added to each current command value Iout_1-Iout_n in order to execute the current control.

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