Optimal Economic Dispatch and Power Generation for Microgrid Using Novel Lagrange Multipliers-Based Method With HIL Verification

Abstract

Microgrid incorporating distributed renewable energy resources (RERs) is increasingly important owing to the goal to reach net-zero emissions by mid-century. This article deals with the optimal energy management of microgrid comprising RERs and battery energy storage system. In addition to considering power flow constraints and uncertainties of RERs, the importance of retaining profits of microgrid operators and the needs for providing extra supports to the main grid are rising. To meet all the requirements, a novel Lagrange multipliers-based method is proposed to deal with equality and inequality constraints simultaneously to directly obtain the optimal economic dispatch solution analytically. Moreover, a microgrid built in Cimei Island of Penghu Archipelago, Taiwan, is investigated to examine the compliance with the requirements of equality and inequality constraints and the performance of the Lagrange multipliers-based method. Furthermore, the comparison of the proposed method with experience-based energy management system, Newton-particle swarm optimization, and deep Q-learning network is provided to evaluate the obtained solutions. Finally, through the hardware in the loop mechanism, which is built using OPAL-RT real-time simulator with floating-point digital signal processor, the effectiveness of proposed Lagrange multipliers-based method is verified and proven to be pragmatic.