Integration of PV power plant through HVDC link using SVPWM based VSI

Abstract

High Voltage Direct Current (HVDC) power transmission links have drawn the interest recently, where the researches have revealed numerous advantages of DC transmission lines longer than 50–100 km over an alternating current (AC) in underground transmission. This paper explores the connection of large Photovoltaic (PV) power plant to the grid using an HVDC link. A maximum power point tracking (MPPT) utilizing perturb and observe (P&O) technique while controlling the opening and closing of the GTO switch of a conventional (DC-DC) boost chopper. Then a three phase 3 levels inverter based on 12-pulse GTO bridges converter relying on PWM command will allow the conversion of the boost output into 3 phase AC while using an LCL filter to reduce the harmonics content and limiting the ripple current. A transformer will allow to increase the voltage level of the inverter output, following it by a 12-pulse rectifier based on Space Vector PWM (SVPWM) control including PI controllers used to regulate the DC link voltage. The grid integration will be insured by a 3 phase 3-Levels inverter, controlled to assure a synchronization with the grid. The entire system is designed and simulated using MATLAB/SIMULINK.