Restart progress of fault in UHVDC after blocking

Abstract

In order to reduce the impact of bipolar blocking on grid stability of restoration and restart process, a unipolar blocking caused by fires in Jin Su ultra-high voltage direct current (UHVDC) as background was taken, using real time digital simulator (RTDS) built a model of DC and AC power grid on both sides, forming closed-loop simulation platform together with UHVDC control and protection true-type device. Based on the simulation platform, unipolar blocking fault caused by wildfire was inversed, and line protection action principle and restarting logic are studied. Protection action and restart during unipolar blocking were studied. Based on simulation platform on RTDS of UHVDC control and protection, the unipolar blocking event was inversed and the simulation result was compared with the actual recorded wave. The results show: operation of the protection device does reflect the line fault.

Keywords

• power transmission faults
• power transmission protection
• power grids
• closed loop systems
• power system simulation
• HVDC power transmission
• bipolar blocking
• grid stability
• restoration
• restart process
• Jin Su UHVDC
• RTDS
• closed-loop simulation platform
• true-type device
• unipolar blocking fault
• line protection action principle
• restarting logic
• unipolar blocking event
• simulation result
• protection device
• line fault