Adaptive controller for static reactive-power compensators in power systems

The paper presents a comparison of the admittance models for static reactive-power compensators along with a microcomputer-based digital model for power-system dynamic-performance improvement. Emphasis is placed on stability, and it is shown that static reactive-power (VAr) controllers (SVCs) can provide significant benefits in terms of increased transient stability limits and improved damping in terms of synchronising power-flow oscillations. Further introduction of a simplified self tuner for the SVC can dramatically increase the power-system performance under a variety of abnormal operating conditions, such as 3-phase short circuits, load shedding, reactance switching, pole slipping and resynchronisation conditions. The self-tuning digital control for the SVC can be easily implemented on a microcomputer. Simulation results for a sample power system using an LSI-11/23 microcomputer are presented in the paper.