During grid-connected operation mode of microgrids, since the main grid provides a large short-circuit current to the fault point, the protection can be performed by the conventional protective devices, but in islanded mode, fault currents are drastically lower than those of grid-connected mode. Hence, employment of traditional overcurrent-based protective devices in micro-grids is no longer valid and some alternative protection schemes should be developed. This paper presents a micro-grid protection scheme based on positive-sequence component using Phasor Measurement Units (PMUs) and a Central Protection Unit (CPU). The salient feature of the proposed scheme in comparison with the previous works is that it has the ability to protect both radial and meshed micro-grids against different types of faults. Furthermore, since the CPU is capable of updating its pickup values (upstream and downstream equivalent positive-sequence impedances of each line) after the first change in the micro-grid configuration (such as transferring from grid-connected to islanded mode and or disconnection of a line, bus, or DER either in grid-connected mode or in islanded mode), it can protect micro-grid against subsequent faults. In order to verify the effectiveness of the proposed scheme and the CPU, several simulations have been undertaken by using DIgSILENT PowerFactory and MATLAB software packages.
|Number of pages||6|
|Publication status||Published - 13 Mar 2018|
|Event||14th International Conference on Developments in Power System Protection: The 14th International Conference on Developments in Power System Protection (DPSP), Belfast, UK - Europa Hotel, Belfast, United Kingdom|
Duration: 12 Mar 2018 → 15 Mar 2018
|Conference||14th International Conference on Developments in Power System Protection|
|Abbreviated title||DPSP 2018|
|Period||12/03/18 → 15/03/18|
- grid-connected mode
- islanded mode
- protection scheme
- positive-sequence component
Mirsaeidi, S., Dong, X., Tzelepis, D., & Booth, C. (2018). A novel approach for protection of radial and meshed microgrids. Paper presented at 14th International Conference on Developments in Power System Protection, Belfast, United Kingdom.