Controller Design and Implementation of Solar Panel Companion Inverters

Abstract

Solar Panel Companion Inverter (SPCI) is a single stage DC-AC power converter, installed
with each solar panel. Each SPCI synthesizes an AC quasi-square wave voltage with
variable pulse width. Width of AC output voltage of each SPCI is proportional to available
power on the solar panel. Output voltages of SPCIs are aggregated across multiple solar
panels connected in series, and a sinusoidal AC voltage is synthesized. In this paper,
dynamic analysis and closed loop current controller design of SPCI is presented. Simulation
results demonstrating the dynamic response of the closed loop SPCI are included. The
closed loop current control scheme is implemented on a hardware prototype to demonstrate
the grid tied operation of SPCI, and experimental results are presented. Maximum Power
Point Tracking (MPPT) algorithm is implemented for Sorted Stair-Case Modulation
(SSCM) in MATLAB Simulink. Experimental results demonstrating MPPT operation are
presented