Reactive power allocation control scheme for multiple grid connected inverters

Abstract

This paper proposes an allocation control scheme to maximize resource sharing of grid connected inverters. Grid connected inverters with diverse capabilities are increasingly present in the utility grid and are regarded as key components in future Smartgrids and microgrids. Due to the aggregation of grid connected inverters in the power network, allocation of their available resources is a new challenge. The focus of this paper is the allocation of reactive power because more economical power distribution systems can be designed through increased flexibility. Thus, reactive power compensation through resource allocation results in deferrals of phased investments for power networks. Additional benefits include minimized transmission losses, enhanced energy efficiency, and improved power quality. In order to effectively allocate resources, selection of the control and communication methods for the inverters are critical because investment costs are relative. A virtual power management system with token ring communication is proposed to increase allocation capabilities. The proposed method acquires the load data of each inverter sequentially. During each turn, reactive power reference values are calculated so that each inverter's resources are properly allocated based on load conditions. A simulation based on the actual load data is used to validate the performance and additional benefits.