| 摘要 |
PROBLEM TO BE SOLVED: To adjust the effective power or the reactive power of an AC system stably with a limited capacity, by a method wherein a voltage drop component produced by the impedance of a transformer is obtained and feedback of the output of an inverter is so controlled as to compensate the voltage drop component. SOLUTION: An impedance drop compensation unit 26 obtains a voltage drop component produced by the impedance of a series transformer 8 in accordance with the bus-bar current IB of a transmission line 2, the impedance of the series transformer 8 and phase information detected by a phase information detection unit 21, and transmits the voltage drop component to respective adders 24 and 25. The voltage drop component is deducted from respective command voltage Vid and Viq outputted by a voltage control unit 23 by the adders 24 and 25 to obtain the d-axis component and q-axis component of the voltage command of an inverter 3. With this constitution, the d-axis component VCd and q-axis component VCq of a series compensation voltage VC inserted into a transmission line 21 in series through the series transformer 8 can be controlled independently at a high speed and stably, and an effective power of reactive power can be stably adjusted. |
