Smart Switching of Multi-terminal Hybrid DC Power Based on Load

A fault protection and location method for a dc bus micro grid system is presented in this paper. If a fault causes the dc bus to de-energize completely, it makes locating faults very difficult. The proposed algorithm can be implemented and executed by an intelligent electrical device for an individual node. The bus was segmented into overlapping nodes and links with circuit breakers (CBs) to isolate the segment in the event of a fault. Backup protection is implemented for circuit breaker failures to improve system reliability. This power can also be used for a pilot test before main CB reclosing to avoid system issues that can be expected when the reclosing fails due to a permanent fault in this paper, we investigate an event-based protection scheme for a multiterminal dc power system, which includes hybrid energy resources and various loading schemes. The proposed protection scheme transfers less data when compared with commonly used data based protection methods, and do not require high-speed communication and synchronization. Each protection unit is able to autonomously identify the type of event using the current derivative fault identification method, employing artificial inductive line impedance. In order to accurately set the protection relays, detailed fault current analysis considering low pass resistor capacitor filter effects are presented. The decision for fault isolation is made based on the unit judgment and the data received through high-level data communication from other inter-connected units. The performance of the proposed protection scheme was evaluated under different dc feeder and bus faults and its shows that this scheme is able to accurately identify the type of fault, isolate the faulted area, and restore the system quickly while limiting the load voltage drop to its preset limit. The result has been evaluated using the PROTEUS DESIGN SUIT simulation software.