Multi-functional grid integrated solar power transfer system with improved FAGI based control for enhanced performance at non-ideal load conditions

Solar energy contributes a major share in sustainable energy-based electricity generation. The solar power transfer system (SPTS) has emerged to integrate solar energy into the distribution network. Moreover, the adverse effects and exhaustible nature of fossil fuels have made the control and design of the SPTS significant. This paper presents a novel grid integration control, named frequency adaptive generalized integral (FAGI) algorithm for a three-phase four-wire SPTS to compensate the reactive power, harmonics and DC offset demands of the sinks connected at the common point, and also eliminates the grid neutral current along with maximum PV array power injection to the grid. The narrow bandwidth bandpass filter property of the FAGI algorithm with adaptive corner frequency improves the fundamental component quality without compromising the response time at adverse operating conditions. The two-stage SPTS uses a DC-DC boost converter for peak power extraction. An enhanced incremental conductance (EIC) algorithm is utilized for its control, which gives simple and dynamic performance over other conventional maximum power point tracking techniques. The system control is developed to meet the load requirements, even at zero irradiance by importing the active power from the grid. Therefore, the major objectives of this work are extracting maximum power, meeting the load demands, and maintaining the grid power quality at any operating conditions. Comparison of FAGI with other common controls, is carried out and the results are produced. The system performances are analyzed at PV-side, load-side, and grid-side disturbances in the MATLAB/Simulink model, and examined the grid power quality compliance with the IEEE-519 standard. An experimental prototype of the system is developed in the laboratory and tested rigorously for multiple dynamic scenarios for validating the reported claims.

Automated summary

This paper presents a novel grid integration control, named frequency adaptive generalized integral (FAGI) algorithm, for a three-phase four-wire solar power transfer system (SPTS). The control method compensates for reactive power, harmonics and DC offset demands, eliminates grid neutral current and maximizes PV array power injection. An enhanced incremental conductance (EIC) algorithm is used for peak power extraction. The system control is designed to meet load requirements and maintain grid power quality.