Design of a low loss voltage source inverter for fuel cell application

Abstract

Proton-exchange membrane fuel cell (PEMFC) is considered the energy of the future, especially in transportation. The output voltage of PEMFC is a DC voltage whose magnitude depends on the load current, but an AC power source is required to power electric motors commonly used in automobile industry. Therefore, this report proposes a drive circuit that converts DC voltage from PEMFC to AC voltage to power AC motors. The drive circuit consists of a boost converter in series with a sinusoidal pulse width modulation (SPWM) inverter. Simulation data of the implementation shows the drive circuit can consistently deliver the desired AC voltage with less than 1.5% deviation to power a 2.4 kW single-phase induction motor in various operating conditions. The harmonic components of the AC output of the drive circuit are highly filtered to achieve low total harmonic distortion (THD) which is less than 1.5% for voltage and less than 0.5% for current. This encouraging result proves the feasibility of the drive circuit model to drive electric motors. Although the electric motors used in automobile industry are threephase induction motors with output power of up to hundreds of kilowatts instead of the 2.4 kW single-phase induction motor used in this report, further improvements can be made on existing model to achieve that. The possible major changes in the report are be replacing the single-phase inverter model with a three-phase inverter and replacing the single-phase inductor motor model with a three-phase four-pole AC motor. Besides, the control algorithms for both inverter and motor to achieve desired output may need to improve.