Validation of fast and selective protection scheme for an LVDC distribution network

Low Voltage Direct Current (LVDC) distribution systems are one of the emerging technologies to recently attract attention for more efficient use of energy, and wider uptake of distributed renewables and energy storage. They do however present significant fault protection and safety challenges, which are not possible to address without using advanced protection techniques. Therefore, this paper considerably reviews these key challenges, and presents experimental results of prototyping an advanced protection scheme developed to help enable LVDC distribution networks for utility applications. The developed scheme is a DC current direction-based using multiple intelligent electronic devices (IEDs) relays in combination with controllable solid-state circuit breakers to detect and locate DC faults, and provide selective protection tripping within sub-millisecond timescales. A scaled laboratory demonstrator that emulates an LVDC distribution network is used as a test platform. It allows the characterisation of the transient behaviour 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.