| 摘要 |
PROBLEM TO BE SOLVED: To reduce the harmonic component of current and excess current even during an abnormal state of voltage of a system, by outputting voltage following the voltage of the system while reducing the harmonic component of a current during a steady time.SOLUTION: A control part 2 that controls a voltage applied to a unit converter and synchronizes voltages output to a power system, comprises; an arithmetic part 21 that calculates a voltage command value on the basis of voltage of power system, current of converter, and voltage of DC voltage source; a phase table one-pulse control part 24 that stores a table of phases for turning on/off a voltage output from the unit converter, refers to the table on the basis of the phase of the calculated voltage command value, and turns on/off voltage output to the unit converter; a command value comparison one-pulse control part 25 that turns on/off voltage output to the unit converter according to a result of the comparison of a voltage command value with a threshold of a change in the voltage output to the unit converter; and a selector 26 that turns on/off voltage output to the unit converter by selectively switching one of outputs of both the one-pulse control parts 24, 25.SELECTED DRAWING: Figure 3 |
