Automatic Switchover System Scheme for 20kV Petal-shape Distribution Network Non-communication Protection

Automatic bus transfer equipment is one of the most effective means to improve the power supply reliability of power system.At present, few domestic 20kV "petal shaped" distribution network operation has considered the use of automatic switching function,So it will extend part of the load power outage time. This paper has improved a automatic switchover system scheme for 20kV "petal" type distribution network which without channel protection. Through coordination of the settle time of the distribution line which between non-channel protection and automatic bus transfer, under the condition that there is no breakdown of the connecting generatrix of the tie ring network switch,except for the longest cutoff time tset,any single phase voltage is below the set voltage and automatic bus transfer can be fast input.Simulation verification by PSCAD/EMTDC,this scheme can effectively improve the reliability and self-healing of the system, and shorten the outage time of the users.