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## Inverters

Q.1
For amplitude and harmonic control , the output voltage can be controlled by adjusting the interval alpha on each side of pulse where output is zero.

Q.2
When using pulse width modulation, which of the following parameters should be considered :

Q.3
In a particular case, some harmonics that were in the spectrum for the bipolar scheme are absent in unipolar switching scheme.

Q.4
The tree phase load connected to this output voltage may be connected in delta or underground neutral wye.

Q.5
The total harmonic distortion (THD) of both the line- to-line and line-to-neutral voltages for a six step inverter is 31%

Q.6
In a six step inverter, output frequency can controlled by switching frequency while output voltage can be controlled by dc input voltage.

Q.7
In a three phase inverter,the 3 arms are delayed by 60 degrees to each other.

Q.8
Each switch in a three phase inverter has a duty ratio of 50%.(not allowing for blanking time) and switching action takes place every T/6 time interval (60 degree angle interval)

Q.9
A full bridge inverter produces a square wave voltage across a series RL load. The switching frequency is 60 Hz. Vdc = 120 V, R = 10 ohm, L = 20 mH. Determine the power absorbed by the load.

Q.10
From the case in question 9 (f = 60 Hz, R = 10 ohm and L = 20 mH), a fundamental frequency current amplitude is 9.27 A. Determine the THD of load current.

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