Protection Schemes for Low Voltage DC Networks

Abstract

The past two decades witnessed the shift of trend from conventional to renewable energy resources, leading to the development in micro-grids. Number of DC appliances in our surroundings has also increased. Major industries such as pulp and paper are using Variable Frequency Drives (VFD) for better control over their machines and minimization of losses. Due to increasing demand of DC systems; efficient as well as effective protection schemes need to be devised. This paper addresses the problem of over and under voltage as well as short circuit in Low Voltage DC (LVDC) system. Disturbance caused by these faults can result in damage of components, loss of energy and can heavily effect the operation of delicate medical and industrial equipment. This paper describes the protection schemes, fault calculations and circuit modeling against over and under voltage as well as short circuit in LVDC system. Solid state switches are used as breaker in circuit model. Finally, validity of the calculations and results are verified by using MATLAB/Simulink software.