基于综合贝瑞隆模型的和导纳保护判据

Pilot protection is the first line of defense for grid security. With the increasing penetration rate of new energy in the power grid, the mal-operation risk exists in both distance and directional protections. In some cases, the above protections may even be forced out of service, which further highlights the importance of pilot protection. However, if the synchronous sampling conditions on both sides cannot be guaranteed, the presently dominant current differential protection will be forced to quit, while summation impedance protection without relying on synchronous sampling has defects such as the inability to select the faulty phase. Therefore, this paper proposes a novel pilot protection criterion based on the comprehensive Bergeron model—summation admittance protection criterion: select a reference point for the line and derive the voltage and current at the reference point based on the classical Bergeron model and local voltage and current at both ends, the admittance on both sides of the reference point can be calculated and summed to form the action quantity. This action quantity is near zero during normal operation and external faults, while it is large enough during internal faults to correctly distinguish between internal and external faults. Aiming at the problem of inability to select the faulty phase in criteria based on the classical Bergeron model, a phase selection criterion based on identical sequence Bergeron model is proposed: replace the zero-sequence parameter with positive-sequence parameter in the classical Bergeron model, which can avoid the occurrence of action quantity in the sound phase, while retaining enough action quantity in faulty phase, achieving correct phase selection for internal faults. The proposed criterion does not rely on data synchronization on both sides and has excellent resistance to transition resistance. The effectiveness and superiority of the proposed criterion are verified through comparative simulation examples.