Development of a predictive pole-slip protection function for synchronous generators

Predictive pole-slip protection is not implemented in commercially available protection relays, since complex modeling of the network and generator is required to do such predictive detection. All pole-slip protection relays on the market will only trip a generator after it has pole-slipped one or more times. This paper introduces a pole-slip protection algorithm, which makes use of a simplified model that still delivers accurate predictive pole-slip prediction. The algorithm uses the equal area criteria for predicting post-fault generator stability while a fault occurs. In order to successfully implement the equal area criteria, a number of parameters need to be calculated (or predicted). This paper will focus on predicting the generator and step-up transformer transient power angles, as well as the step-up transformer post-fault voltage, which are required to successfully use the equal area criteria for predicting pole-slipping.