Department of Power Electronics and Energy Control Systems, AGH University of Krakow, Krakow, Poland
Krishna Kumar Gupta
Department of Electrical and Instrumentation Engineering, Thapar Institute of Engineering and Technology, Patiala, Punjab, India
Pallavee Bhatnagar
Department of Electrical and Electronics Engineering Education, National Institute of Technical Teachers’ Training and Research, Shamla Hills, Bhopal, Madhya Pradesh, India
This paper presents a novel concept of a DC-AC converter that ensures AC voltage modulation on four levels using a single branch and achieves voltage boosting. The proposed boost inverter is based on a single-stage topology and does not use a DC-DC boosting part. Compared with a cascaded boost inverter topology, the proposed converter is bidirectional and allows operation at a lower DC-link voltage, which reduces voltage stress across devices. The inverter topology contains an additional DC capacitor. An adequate voltage level for this capacitor is maintained by a switched-capacitor-based (SC)-based balancing circuit. The balancing process is of low complexity because it only requires the synchronization of the SC branch control signals with the PWM of the inverter. The balancing circuit operates in resonant mode to avoid inrush currents. The main power circuit of the converter does not use diodes, and can be adequate for MOSFET or GaN-based implementations. It can be configured as a single-phase or multiphase system. The results presented in this paper demonstrate the correctness of the converter concept and its modulation, voltage stresses of switches, and balancing process of the auxiliary capacitor. The experimental results confirm the feasibility of this concept and demonstrate the operation and efficiency of the inverter.
