Fault Analysis And Protection Technology Of DC Distribution System

The ever rapid growth of load and increasing requirement of power quality bring a great challenge to traditional distribution systems. DC distribution system is attracting more and more attention due to its potential of high power quality. It’s the vision of DC technology to supply urban centers by DC distribution system to solve problems such as heavy load, lack of power supply corridor and the urgent demand to improve power quality. With the lack of mature yet economical DC CBs (DC circuit breakers) and operation experiences, the protection technology has become the bottleneck of DC distribution system. This paper firstly gives an overview of DC distribution system and the dilemma of protection technology. Protection zones and fault types are illustrated with specificity analysis and simulations in PSCAD of typcal faults in each zone. Then, the development of fault isolation devices and fault current limiters is discussed, followed by possible fault protection solutions and issues that need attention of each zone. Future work considering the protection in DC distribution system is proposed in the last part.