A Practical Approach to Mitigate the Harmonic Distorsion in a Microgrid, Case Study

The actual study proposes a power quality analysis of a medium-sized industrial microgrid which in turn generates harmonic disturbances on the medium voltage side of a 110kV/20kV substation. Due to the interconnection of different loads on similar medium voltage busbars, the harmonic distortion propagates along the circuit affecting the stability of the local grid. Using advanced simulation tools based on numerical analysis an equivalent circuit of the microgrid is created. According to the computed results levels of total harmonic distortion exceeding the limit values imposed by the national performance standards were discovered within the load understudy. In this regard, a complex analysis procedure targeting the variable speed drives is deployed in order to identify the proper technical solutions for attenuation and filtering of harmonics in the system. Therefore, this study highlights solutions for mitigating the higher-order harmonics and the impact of their implementation, i.e. the best solution.