Abstract:It is presented to sequentially check the protection of values based on protection importance in order to make the online check relay protection more effective and reasonable. Firstly, the information entropy is introduced to consider the influence of power flow direction based on active power betweenness, which overcomes the shortcomings of active power betweenness ignoring directional line power flow. Meanwhile the power grid is considered as a directed and weighted network and the actual running state of line is taken into account, making the physical background even more suitable for the condition of the power system. Then, the protection of important degree is different when relay protection device is located in different place of the grid. The improved active power flow betweenness of line and node are integrated to measure the importance of different protections, and the protections are arranged according to the importance order from high to low. On the basis of the descending order of protection importance, all the protection of values can be verified online. Finally, the example of simulation shows that this method is correct and effective.