A Single-Source Switched-Capacitor 13-Level High Gain Inverter With Lower Switch Stress

Abstract

A switched-capacitor based 13-level inverter with high gain and reduced switch stress is presented in this article. The 13-level single-phase ac output voltage is achieved with a voltage gain of 6 by utilizing a single dc source, 14 switches, 3 capacitors and 1 diode in the proposed converter. Self-voltage balancing is achieved for different types of loads without the use of complicated control schemes or supplementary circuitry. The proposed topology can generate negative polarity without a back-end H-bridge. Consequently, voltage stresses across the switches are reduced. The voltage stress across the switches is limited to 4 times the input DC voltage. Included also is an analysis of power loss for several components of the proposed converter. A comparison is made with contemporary topologies that require a single dc source at the input in terms of several performance characteristics. Resistive (R) and resistive plus inductive (R-L) loads are simulated in this study. To demonstrate the effectiveness of the suggested converter, a laboratory prototype is constructed. In order to demonstrate the viability of the suggested arrangement, the experimental results for step variation in load demand and variation in modulation index under practical loading situations are obtained.

Keywords

• Multilevel inverters
• nearest level modulation
• switch stress
• switched capacitor
• single source
• microgrid