Fuse-Based Short-Circuit Protection of Converter Controlled Low-Voltage DC Grids

Abstract

Low Voltage DC microgrids emerge as a viable alternative to AC microgrids. A large research interest is noted towards fast and selective protection of DC grids, typically focusing on hybrid or full solid state solutions. In this paper, the use of fuses as short-circuit protection in Low Voltage DC microgrids is evaluated. The main advantage of fuses is that they are simple, cheap, standardized and have low steady state losses. A theoretical basis is formed to model DC short-circuit currents in grids with a limited short-circuit availability. The outcomes are applied to evaluate the possibilities of fuse protection in LVDC grids. It was found that fuses are an effective means of protection, although the required amount of capacitance at the output of the voltage balancing converter can be high, which impacts the total system cost. A fuse based protection strategy is presented that highlights the need for additional capacitance to clear faults compared to the necessary capacitance for system stability. An experimental setup was built to validate the claims.

The Diagnostic Method for Open-Circuit Faults in Inverters Based on Extended State Observer

“…(e a , e b , e c ) are opposite electromotive forces, R is the stator winding resistor, and L is the stator inductor. F 1 ∼F 6 are fast fuses that convert short-circuit fault into open-circuit fault [2], so this paper only studies the diagnostic method of open-circuit fault.…”

“…Short-circuit fault occurs for a short period and cannot be diagnosed by software algorithms. Inverter short-circuit fault can transform into an open-circuit fault due to the break of the connecting fast fuses in the circuit, so the short-circuit fault can be diagnosed by the open-circuit faults diagnostic method [2]. At present, the diagnostic methods of IGBT open-circuit fault are classified into the current-based method, the voltagebased method, and the intelligent algorithm methods.…”

Circuit Breakers in Low- and Medium-Voltage DC Microgrids for Protection against Short-Circuit Electrical Faults: Evolution and Future Challenges

“…In the Ref. [52], a detailed analysis of fuses used in power converters was presented. Fuses were found to be an effective means of protection, although the required amount of capacitance at the output of the voltage-balancing converter can be high, which affects the total cost of the system; therefore, in terms of power converters, the ideal application is to use the fuses as backup protection for the main switch.…”

The implementation framework of a microgrid: A review

“…The challenge arises with the largely varying SCC between the operating configuration due to the varying power sources and loads 43‐45 …”

“…The challenge arises with the largely varying SCC between the operating configuration due to the varying power sources and loads. [43][44][45] • Analysis on protection and co-ordination: With the varying and low SCC, the protection study becomes vital. The microgrid setup must be designed with efficient protection equipments and personnel safety along with a coordinated and sequenced operation of protection devices.…”