Understanding Power System Stability

This paper discusses power system instability and the importance of fast fault clearing performance to aid in reliable production of power. Explanation is provided regarding small signal stability, high impedance transmission lines, line loading, and high gain, fast acting excitation systems. Transient stability is discussed, including synchronizing and damping torques. The power angle curve is used to illustrate how fault clearing time and high initial response excitation systems can affect transient stability. The term, "power system stability" has become increasingly popular in generation and transmission. The sudden requirement for power system stabilizers has created confusion about their applicability, purpose, and benefit to the system. This paper discusses the fundamentals of the power system stabilizer and its effectiveness. In today's paper industry, power system stabilizers are being applied on larger machines in the Northwest United States and Canada.