Control Protection Collaborative Fault Current Correction Method for New Energy Transmission Lines

With the proposal of carbon peaking and carbon neutrality goals, China is accelerating the construction of a new type of power system dominated by new energy. The integration of new energy into the grid cannot be achieved without a high proportion of power electronic equipment. The fault ride through control of large-scale new energy transmission lines introduces weak fault characteristics such as fault current limiting and power frequency phasor phase uncertainty. Traditional protection methods have limited adaptability, such as differential protection and distance protection, both of which have the risk of refusal and mis-operation. In response to this issue, current research has proposed improvements to traditional protection and new protection principles based on transient quantities. This article considers correcting fault currents and restoring weak fault characteristics caused by control, thereby expanding the adaptability of traditional protection. A theoretical method was proposed to correct the amplitude and phase of the fault current caused by control under known fault crossing control standards, and its correctness was verified through simulation. The proposed method does not require a complete replacement of protective devices and is economical, reflecting the concept of coordinated integration of control and protection in the new power system, and expanding the reliable implementation of protection in the new power system.