Multi-objective operation of renewable multi-microgrids integrated with energy storage system considering power losses and harmonics

Abstract

This paper presents a tri-objective decision-making approach for optimal energy scheduling of multi-microgrid systems in distribution systems. The proposed model is developed as a three-layer problem. The first layer performs a stochastic model to consider the uncertainty of renewable generation, load, and electricity prices. At the second layer, a multi-objective model was performed to optimize the operation cost, carbon emission, and unsupplied load simultaneously. In this layer, a centralized model is proposed for the cooperation of the microgrids to reduce their operation cost by sharing their distributed energy resources. To handle the multi-objective problem, a normalized compromised programming approach is applied to convert the original problem into a single objective. The results of the second layer have been imported into the third layer. The last layer focuses on network limits and power flow constraints. Both fundamental and harmonic power flows are analyzed to ensure compliance with power loss limits and power quality indices, including harmonic losses and the maximum THD of buses. The proposed three-layer model is tested on an IEEE 33-bus standard test system and the simulation results show it reduces the carbon emission, power losses, and maximum THD by 31.61 %, 15.52 %, and 2.2 %, respectively.