Requirements for testing of power swing blocking functions in protection IEDs

The 2003 North American blackout demonstrated the importance of power swing detection, blocking and tripping for the development of a wide area disturbance into a system-wide blackout. Modern microprocessor based multifunctional protection IEDs have advanced or traditional power swing detection functions that can be used successfully to provide stability in the performance of the distance elements, while at the same time ensuring that they will clear a fault if it occurs during a power swing. The paper first introduces some of the power swing detection methods and methods for fault detection during a power swing. It then focuses on the requirements for testing of these functions and describes some methods for testing based on, replay of actual events, transient simulation of synchronous power swing, transient simulation of asynchronous power swing, transient simulation of power swing with a short circuit fault. The benefits of these methods are discussed in the the paper compared to more conventional methods.