Harmonics assessment and mitigation: A case study on an unbalanced stand-alone microgrid integrated with PV

Different from the conventional grid system, the microgrid provides two operation modes: grid-connected and stand-alone. In stand-alone mode, microgrid is also capable of delivering power to customers due to the integration of renewable energy sources and energy storage. However, there are some potential problems with this benefit, such as, harmonic distortion. In order to analyze the harmonic distortion influence on a stand-alone microgrid, a case study was conducted. By building microgrid models in the Matlab/Simulink platform, harmonics can be monitored and assessed. To solve this power quality problem, an active power filter model is integrated to mitigate high frequency harmonics. Simulation results are compared through two proposed indices for power quality measurement: Total Harmonics Distortion (THD) and Whole System Harmonics Distortion Level (WSHDL).