Southern California Edison Company

Bharat Bhargava

An electrical power distribution system having geographically separated plural generation stations and geographically separated loads is improved by dynamically offsetting a nominal real power operating point of a main control system driving a power control element that variably feeds electrical power onto a network of transmission lines between the stations and the loads in response to deviations in frequency and/or phase of alternating current power on the network. The generation station can include an actuator control circuit for driving the control element in response to a power setting signal, the actuator control circuit incorporating a delay component, an offset signal connection downstream of the actuator control circuit bypassing the delay component. Preferably the system further includes means for monitoring a threshold level of the deviations, and means for inhibiting the means for dynamically offsetting until the deviations exceed the threshold level. Thus the real power compensation is applied selectively under high levels of power transfer between geographically distant locations, when the system has a dominant characteristic frequency of oscillation that is lower than an ordinarily dominant local characteristic frequency of the system. Also disclosed are methods for improving stability of a power distribution system.

Energy service stabilizer

Subsynchronous resonance is detected in an electric a.c. power supply system by determining changes in wave parameters of substantially successive half cycles and applying said changes as a relationship of said subsynchronous resonance. The parameter change measured is the wave period, and changes in the ratio of the difference of the period of positive and period of negative half cycles over the sum of the period positive and the period of negative half cycles is related to detection of subsynchronous resonance.

Growing community of inventors

Walnut, CA, United States of America

Bharat Bhargava