TY  - JOUR
AB  - Equal power-rating inverters operating with different power set-points in either an islanded or grid-connected mode may lead to inter-unit circulating power caused by a large mismatch between power generation and demand during network contingencies (faults on the heavy load side or unintentional islanding). This circulating power may violate the dc-link voltage limit and, as a result, the protection scheme may shut down the inverter and reduce the microgrids reliability. This paper proposes a regulator for controlling the dc-link voltage of the microgrid's inverter during a period of circulating power. It includes a discharging resistor with a series-connected switch across the dc-link capacitor which is turned on through a control algorithm if the dc-link voltage exceeds its pre-defined limit. Case studies of parallel-connected inverters are conducted and their stability assessed through a small-signal analysis. In addition, a realistic microgrid is designed as a low-voltage (LV) network and tested to verify the concept and regulator actions presented. The simulation results validate the effectiveness of the proposed regulator during network contingencies.
AU  - Hossain, MA
AU  - Pota, HR
AU  - Haruni, AMO
AU  - Hossain, MJ
DA  - 2017/06/01
DO  - 10.1016/j.epsr.2017.02.026
EP  - 244
JO  - Electric Power Systems Research
PB  - Elsevier
PY  - 2017/06/01
SP  - 233
TI  - DC-link voltage regulation of inverters to enhance microgrid stability during network contingencies
VL  - 147
Y1  - 2017/06/01
Y2  - 2026/05/10
ER  -