Low-cost 13-level switched capacitor inverter topology under variable load conditions

Abstract

This paper presents a low-cost 13-level switched capacitor inverter (SCI) topology designed for efficient and reliable operation under variable load conditions. The proposed topology significantly reduces the number of power switches, gate drivers, and passive components by eliminating the need for transformers and multiple isolated DC sources, making it ideal for compact and cost-sensitive applications. The inverter uses a combination of switched capacitor cells and a single DC input source to generate thirteen distinct output voltage levels. An inherent voltage boosting feature and self-voltage balancing mechanism simplify control and ensure high-quality output without complex feedback systems. A low-complexity modulation technique is employed to manage switching, minimize losses, and maintain a near-sinusoidal output waveform with low total harmonic distortion (THD). The design effectively handles dynamic load variations while maintaining voltage stability and operational efficiency. Detailed simulation and hardware implementation confirm that the inverter delivers consistent performance in terms of voltage regulation, harmonic suppression, and thermal efficiency, even under fluctuating load conditions. The proposed topology offers improved power density, reduced voltage stress across components, and a simplified structure compared to conventional multilevel inverters. This makes it a practical and scalable solution for renewable energy integration, standalone power systems, and other distributed generation applications requiring compact and economical inverter solutions.