High Power Transformerless Photovoltaic Inverter

This paper presents a new topology of high power three-level transformerless photovoltaic inverter (TPVI). It consists of three main circuits; they are a pulse driver circuit, a full bridge inverter (FBI) circuit and a power factor correction (PFC) circuit that have functions as production of pulse waves, to develop alternating current (AC) waveform and to stable voltage of PV array, respectively. To obtain the high power of the TPVI, five FBI circuits are connected in parallel. Each FBI circuit uses MOSFET IRFP460 which has rating current of 20 A, therefore the total FBI circuit has applicable maximum current of 100 A. The high power TPVI is installed in front of Centre of Excellent for Renewable Energy (CERE), Universiti Malaysia Perlis, Northern Malaysia. Its main energy source is a PV array that consists of three unit PV modules are connected in series, each unit has 81 V, 60 W. Some three unit PV modules are connected in parallel to fulfill the demand of high AC power. In this research, an AC three-level waveform of the TPVI is developed and created by a microcontroller PIC16F627A-I/P.