Subsynchronous resonance is a condition that can exist in a power system where the network has natural frequencies that fall below the fundamental frequency of the generated voltages. Transient currents flowing in the ac network have two components; one component at the frequency of the driving voltages and another component at a frequency that depends entirely on the elements of the network.

For a network with only series resistance and inductance, an isolated transient, such as switching a load, will consist of a fundamental component and a de component that decays with a time constant that depends on the LIR ratio of the equivalent impedance between source and load. Since loads are frequently switched on and off, the transient currents usually appear as random noise, superimposed on the fundamental frequency currents.

The addition of shunt capacitors to the network result in new natural frequencies of oscillation that are always greater than the fundamental frequency. In networks containing series capacitors, the currents will include oscillatory components with frequencies that depend on the relative magnitude of the transmission line Land C elements but have frequencies that are below the system’s fundamental frequency.

Related topic – click here

Aanchal Gupta

Welcome to my website! I'm Aanchal Gupta, an expert in Electrical Technology, and I'm excited to share my knowledge and insights with you. With a strong educational background and practical experience, I aim to provide valuable information and solutions related to the field of electrical engineering. I hold a Bachelor of Engineering (BE) degree in Electrical Engineering, which has equipped me with a solid foundation in the principles and applications of electrical technology. Throughout my academic journey, I focused on developing a deep understanding of various electrical systems, circuits, and power distribution networks.

Leave a Reply