A Novel Method for Pilot Protection Based on Current Fault Component

With the development of the scale of the power grid, Relay protection has gradually become an important part of ensuring the smooth and safe operation of power system while Pilot protection has also gradually become an important development direction of high-voltage line protection in the process of Relay protection development. Based on the research and comparison to the existing methods of current comparison pilot protection, direction comparison pilot protection and distance comparison pilot protection. In this paper, a protection method based on the characteristic of fault component of current at both ends of the circuit is proposed to overcome the disadvantage of the current differential protection scheme which is easily affected by the load current and the transition resistance, and the protection method is adopted which based on the instantaneous value of current fault component. In order to verify the rationality of the method which is proposed, an appropriate simulation model is designed, a simulation system is established, and various possible situations in the power system are simulated by using the simulation system. Simulation shows that the judgment based on the value of the fault current as a protective action has the following advantages: Firstly, the calculation is simple which only compares and judges the size of the fault component without real mathematical operations; Secondly, this method has lower requirements for the communication channel, which only a very simple signal needs to be transmitted when a possible fault is found; In addition, the action is fast, and only the instantaneous value of the fault component of the current can determine whether the action is or not.; Finally, the action is reliable, the judgment of this method is very reliable and will not refuse to acting. At the same time, it can avoid the influence of harmonics and other factors by adjusting the action threshold, which ensures that the protection will not malfunction.