# V / F constant control of induction motor with inverter

1. Nov 7, 2013

### MissP.25_5

Hello. I have to do an experiment on this topic, but there are many things I don't know. First of all, can you tell me what do the symbols V~ and A~ mean?

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2. Nov 13, 2013

### MissP.25_5

Can someone tell me why is the output voltage of the converter bigger than the output voltage of the inverter? The output voltage of the converter would be a DC voltage whereas the output voltage of the inverter would be an AC voltage.

3. Nov 13, 2013

### rude man

AC volts and AC current.

4. Nov 13, 2013

### rude man

Why shouldn't it be?

5. Nov 13, 2013

### MissP.25_5

Hmmm, I guess the reason is the output voltage of the converter is the supply voltage for the inverter and output voltage can never exceed the input voltage. But I am not sure if that's enough reason for that.

6. Nov 14, 2013

### rude man

???

You can get any output voltage > or < input voltage with the right design.

For example, I have an inverter sitting in my garage that converts 12 VDC from a car battery to 115V AC 60 Hz to drive my TV set etc. if there is a power outage in my house.

7. Nov 14, 2013

### MissP.25_5

But the supply voltage, which is the output voltage of the converter should be bigger than the output voltage of the inverter, right? That's my question and I am trying to find the reason for that. I just guess that it's because the output voltage can't exceed the voltage supply. I said input earlier, I meant to say supply.