A single-source nine-level boost inverter with new optimal switching scheme for EV applications

The importance of two-level inverters is well known in EV applications; it contains significant unwanted harmonics in generated voltage. One of the most efficient way to increase power quality is to replace a two-level inverter with a multilevel inverter (MLI). The MLI's essence considerably reduces total harmonic distortion. Eventually, the size of the filter requirement also will minimize. Because of the increased device count and capacitor voltage balance issues, these converters have a slew of reliability concerns. To mitigate these drawbacks, a novel switched-capacitor based nine-level inverter (SC-NLI) structure with a new optimal control switching technique for electric vehicle (EV) applications is proposed in this paper. The proposed SC-NLI structure comprises 10 switches, one diode, and two capacitors. The proposed structure's circuit description, modes of operation, proper component selection, and a new optimal switching scheme are presented. A discussion about the comparative analysis of suggested topology with currently developed MLI structures is presented. In addition, to the simulation results, experimental tests are conducted under various load conditions to evaluate the proposed SC-NLI structure. The salient features of the proposed work constitute 1. Reduced component count 2. The output voltage gain of four for nine-levels 3. Capacitors are capable of self-voltage balance and easy controlling 4. Does not require an additional H-bridge to produce bipolar levels 5. Improved quality of output waveforms with the proposed optimized switching techniqueimage