| 摘要 |
PURPOSE:To eliminate the need of sampling synchronization in a transmission path for estimating the voltage phase difference by estimating the voltage phase on the counterpart side of a transmission line based on the voltage, current and impedance at the end of the transmission line. CONSTITUTION:Upon occurrence of disturbance on a system, a central unit 7 estimates the internal voltage phase of a generator in the system based on the bus voltage in a power station 2 and the output current of generator. At the same time, the central unit 7 estimates the bus voltage in a power station 6 based on the bus voltage and the current flowing through a transmission line 3 and the operates the phase difference from the voltage at its own end. A terminal unit 8 estimates the bus voltage at the transforming station 6 based on the bus voltage at a transforming station and the current of a transmission line 4 and then operates the phase difference of bus voltage between the transforming stations 5, 6. The phase difference estimated by the terminal unit 8 is delivered on a transmission line 9 to the central unit 7. This constitution eliminates the need of sampling synchronization on the transmission line for estimating the voltage phase difference. |
