Validation of Fast and Selective Protection Scheme for an LVDC Distribution Network

摘要

Low-voltage direct-current (LVDC) distribution systems potentially enable more efficient power distribution and wider uptake of distributed renewables and energy storage. They do, however, present significant fault protection and safety challenges. To address these, the use of advanced protection techniques or significant system redesign is required. This paper reviews these protection key challenges, and presents experimental results of a prototype advanced protection scheme designed to help enable LVDC distribution networks for utility applications. The developed scheme is DC current direction-based and uses multiple intelligent electronic devices relays in combination with controllable solid-state circuit breakers to detect and locate DC faults. This scheme provides selective protection tripping within submillisecond timescales. A scaled laboratory demonstrator that emulates an LVDC distribution network is used as a test platform. It allows for the characterization of transient behavior for various fault conditions and locations. The developed protection algorithm is implemented in LabVIEW, and its performance against such fault conditions is tested within this environment.