Low Voltage Direct Current (LVDC) distribution is one of the new promising technologies that have the potential to accelerate the wider integration of distributed renewables. However, adding new power electronics to convert AC to DC will introduce new forms of faults with different characteristics. Converters with inherent fault current limiting and blocking capabilities will significantly limit the fault currents, resulting in significant impacts on the performance of existing LV overcurrent protection schemes. New protection methods based on the change in the DC voltages have been proposed recently by different researches. The issue with these methods is that the protection relays of the un-faulted feeders will also see the same change in the voltage for certain faults, leading to substandard selectivity and unnecessary tripping. This paper investigates these challenges, and presents a novel DC protection method which is based on the use of the combination of two components: the voltage change (dv/dt) and the change of current (di/dt). The new method is mainly developed to detect and locate DC faults with reduced fault current levels within DC distribution networks. The introduced protection concept is tested on an LVDC distribution network example using PSCAD/EMTDC simulation tool.
|Publication status||Published - 29 Jun 2017|
|Event||The 2nd International Conference on DC Microgrids (ICDCM2017) - Nurnberg, Germany|
Duration: 27 Jun 2017 → 29 Jun 2017
Conference number: 2nd
|Conference||The 2nd International Conference on DC Microgrids (ICDCM2017)|
|Period||27/06/17 → 29/06/17|
- DC protection
- modular multilevel converter
- LVDC distribution systems
Wang, D., Emhemed, A., & Burt, G. (2017). A novel protection scheme for an LVDC distribution network with reduced fault levels. Paper presented at The 2nd International Conference on DC Microgrids (ICDCM2017), Nurnberg, Germany.