Droop control implementation on hybrid microgrid PV-diesel-battery

Abstract

Electricity in rural area of Indonesia is mostly in small-scale with diesel generator as the main power source. These diesel generators are mostly in the latter stage of operational age, thus have limited capability and poor performance. Microgrid has been introduced lately, as a system to integrate more renewable energy sources to the existing power system. Photovoltaic (PV) source is one of the most popular renewable energy source which is utilized by microgrid. However, the fluctuating characteristic of microgrid operation and the intermittent characteristic of PV are making it harder for diesel generator to maintain the stability of the system. This situation might lead to further diesel generator performance degradation, causing operational and maintenance costs to rise. This research proposes a microgrid concept consisted of PV, diesel generator, and battery, aiming to minimize the impact for diesel generator caused by PV integration. Droop control is utilized to enable load sharing between diesel generator and PV source through grid-connected inverter. This scheme will enable the PV and inverter to participate in maintaining system operation and ease the operation of diesel generator. A battery energy storage system is introduced as a buffer to further enhancing system stability. It can be shown that under this scheme a microgrid with PV is able to actively participate in maintaining grid condition by sharing load with diesel generator, assisted by the battery as a buffer.