Cascaded H-bridge Multilevel Inverter for Photovoltaic Applications

Abstract

In this work, a novel single-phase cascaded multilevel inverter is proposed based on the H-bridge units. The proposed topology increases the output voltage levels by reducing the power electronic devices such as switches, power diodes, dc voltage sources and driver circuits that help to reduce the inverter cost and installation space. This topology not only reduces the number of power electronic devices but also reduces the amount of voltage blocked by the switches. This advantage is due to the developed HBridge. Normally, a single conventional H-bridge can generate 3 levels at the output, which utilizes 4 power electronics switches and 2 dc voltage sources. When three conventional H-bridge are connected in series, it can generate 7 levels in the output. This conventional circuit utilizes 12 switches and 3 dc voltage sources. In order to reduce power electronics devices, conventional H-bridge is modified with 6 switches and 2 DC voltages. This developed H-bridge can generate 7 levels atthe output. In this case, utilization of switches and the dc voltage source get reduced. By using this topology, it is conceivable to generate any number of levels at the output with a minimum number of power electronic devices.