Active power management in a low-voltage islanded microgrid

Growing electricity demand and scarcity of energy sources are the driving force of exploration of renewable energy sources. However, uncertain energy production of these sources creates difficulties in their control and operation with or without a grid utility connection. This paper proposes a novel power control strategy which employs a voltage band in the DC-link voltage to maintain voltage stability and thereby improve the power quality during temporary disturbances in a network. It is applied to act as an inverter's inertia and obtain maximum benefit from the storage system, based on the features of a DC busbar to avoid a voltage limit violation. It also proposes a demand dispatch strategy based on a client's terminal voltage, which avoids the complexity of communication lines, to balance the network power during power shortages. The developed control algorithm is tested on an IEEE 16 bus test feeder with multiple DG units and from the results it is found that the proposed control methods provide effective control of the voltage and power quality during transient conditions and scarce power generation.