Implementation and Performance Evaluation of a Low-Cost Current-Source Grid-Connected Inverter for PV Applications

This paper investigates the performance of a 150W single-phase current-source grid-connected inverter for PV cells. The constant-current source is realised using a DC link inductor and the inverter is implemented using a single boost switch, a H-bridge inverter and an LC output filter. Although the DC link inductor causes the inverter to be less efficient than an equivalent voltage-source inverter, it offers lower cost due to the zero-current switching and lower number of components. In addition, the output current is easily controlled using the boost switch and simple open-loop control. The inverter input is simulated using the dark I-V configuration of two PV cells. The advantage of this arrangement is the ability to conveniently simulate the PV cell over a wide range of irradiances. The entire system is implemented to verify the simulation results. Furthermore, the paper also examines the proposed inverter's ability to deliver sinusoidal current to the grid whilst meeting the appropriate standards, i.e. total harmonic distortion and power factor requirements. Additionally, the inverter's ability to maximise the PV cell and inverter output power is shown.