VSSMLMS-based control of multifunctional PV-DSTATCOM system in the distribution network

The variable step size modified least mean square (VSSMLMS) learning algorithm based multifunctional double-stage grid interactive photovoltaic (PV) system is implemented in this paper which feeds power to the grid and the load, ensures unity power factor operation and compensates reactive power. Along with this, it mitigates high grid neutral current during unbalanced loading condition. This algorithm uses variable step sizes to have a smooth dynamic and steady state performances. The boost converter (booster) is used in the first stage to extract peak power from a PV array using perturb and observe peak power point tracking technique. Next to this, a four leg voltage source converter (VSC) is placed to interlink the solar PV system to the grid and the loads. VSSMLMS-based control technique is used to filter the fundamental component of load current and hence gate pulses are generated for the four-leg VSC. This system is simulated in SIMULINK/MATLAB software under several working conditions and the obtained simulation results are validated on a developed laboratory prototype. The performance of the VSSMLMS-based control technique is compared with that of the traditional LMS-based technique. All results validate the IEEE-519 standard.