Design a dc/ac inverter circuit for use with a solid oxide fuel cell (dc source)to meet the following requirements: The fuel cell’s out voltage ranges between 450 V and 650 V; A typical three phase inverter will be used.
a) If sinusoidal PWM (SPWM) is used to control the inverter, what is the range of modulation index for the inverter to provide three phase 240 V (line-line RMS) 60 Hz output?
b) If six step PWM control is used for the three phase inverter, what is the output voltage range of the inverter?
c) Discuss: which control method, SPWM or six step, would result in higher active power consumption, if
- the fundamental component of the output voltages from these two methods are the same;
- the loads for both methods are the same per phase.