Generalized Normalized Gradient Descent Based Control Algorithm for Solar PV Integrated 3P4W Distribution System

This paper presents a generalized normalized gradient descent (GNGD) based intelligent control algorithm for a solar PV array integrated 3-phase 4-wire distribution system. This system is based on single stage topology. It contains a three-phase 4-leg two level voltage source inverter (VSC), which executes multi-task functions, depending upon the system requirement and operating condition. It extracts the peak power from the solar PV array, improves the grid current power quality by mitigating the load current harmonics, reduces the reactive power burden and provides the load balancing on the distribution system and mitigates the AC mains neutral current. The VSC is controlled by GNGD based intelligent control algorithm, which estimates the magnitude of the fundamental component of load current. Instead of using a priori error concept to update the weight, this control algorithm uses a posteriori error based concept to improve the steady state performance. The incremental and conductance (INC) based control algorithm is utilized to extract the peak power from the PV array. The performance of the control algorithm is validated through simulation results and test results obtained on a developed laboratory prototype.