| 摘要 |
PURPOSE:To prevent step out of system by predicting the step out due to unstable mode of the system and carrying out various system stabilization control based on the prediction. CONSTITUTION:Upon occurrence of disturbance in a transmission system 12, voltage detectors 14a, 14b sample bus voltages at typical power stations 13a, 13b in large power source systems 11a, 11b with predetermined intervals, then the sampled bus voltages are fed through transmission systems 15a, 15b to an operating section 16. The operating section 16 measures the difference 4 of times when the bus voltages at the power stations 13a, 13b cross zero point and operates a differential voltage phase angle between them. Thereafter, the operating section 16 predicts the differential voltage phase angle at a future point based on the differential voltage phase angle. Stability between the systems 11a, 11b is judged based on whether the predicted differential voltage phase angle exceeds over a preset threshold. When unstability of system is detected for a predetermined time, the operating section 16 provides a control command to a system stabilization controller thus preventing step out of the system. |
