Model predictive control of three phase voltage source converters with an LCL filter

Industry regulations and standards are placing ever increasing limitations on the individual and total harmonic distortion levels that can be injected into the grid and hence an LCL circuit becomes an attractive option to interconnect an inverter to the utility grid. However, despite the benefits of LCL filter in reducing the switching harmonics, the inherent resonance present in this filter can cause a closed-loop stability problem due to increased grid current distortion. This paper develops a model predictive based current control for a three-phase grid connected converter with an LCL filter. The objective is to provide fast tracking response of the desired system reference coupled with suppression of the resonance disturbance caused by the LCL filter.