The degree of coupling analysis method based on current injection

The quantization method of coupling degree is proposed and used to identify the critical nodes in the power system. This method combines the change of injection current on the basis of network analysis technique. The degree of coupling between the various parts of the power grid after the disturbance can be analysed by this method which overcomes shortcomings of ignoring the different operation states when the network technology is applied to the power grid. The proposed index can accurately reflect the influence degree and has a very clear physical meaning. The proposed method is more in line with the actual situation of the power system when compared with the existing complex network model by the application of the IEEE standard sample system. The method is also simulated on the actual central province Power Grid in China, and result shows that the concept of coupling degree is easy to calculate and can real-time track status changes.