Input and output currents of the inverter.

Janaki D

Relation between Input current and the output current of the inverter.

The input to the inverter is 12V Battery and motor is for example is continuous is 2KW and peak is 4KW. I have few questions here

a. If the operating voltage of the inverter is for example from 9V to 15V, the Peak input current of the inverter is 4KW / 9V = 444 Amps and the continuous input current of the inverter is 2KW/20V = 222 Amps. Are my calculations correct? Please help.

b. I don't know how to calculate the Irms and the Vrms values at the output of the inverter Irms_peak, Vrms_peak, Irms_continuous, Vrms_continuous. Any support i can try and derive.

over 3 years ago

0 Yunsheng Qu over 3 years ago

TI__Genius 9790 points

Hi, janaki

If the waveform of output voltage/current is sine wave, then Irms*√2=Irms_peak, and Vrms*√2=Vrms_peak.

Yunsheng

0 Janaki D over 3 years ago in reply to Yunsheng Qu

Prodigy 50 points

Thank you but I have not made my question clear. Can I make an estimate of the Ipeak and Vpeak? Do I need to know any other parameter to make an estimate of Ipeak and Vpeak? Please advise.

0 Yunsheng Qu over 3 years ago in reply to Janaki D

TI__Genius 9790 points

It is based on your output voltage. If your output voltage is 220Vrms sine wave, then Vpeak=√2*220V. And Ipeak=√2*4kw/220V

0 Janaki D over 3 years ago in reply to Yunsheng Qu

Prodigy 50 points

Thank you for support. But how do I know my output voltage.

The background of this question is I know the PMSM motor parameters it is 48V, Max required torque is 20Nm and have the back emf waveforms available.

Now I have to design a controller to achieve these requirements, I want to select the maximum ratings of the MOSFETS, for this I want to calculate the maximum phase current I need to produce? Please help me to understand did U already answered and I could not understand?

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Input and output currents of the inverter.