openinverter forum

Hello all. Obviously this question comes from holes in my knowledge base, specifically around motor rpm, inverter boosting capabilities, pack voltage and how they relate.
For example, with a 24s pack, how fast could you spin a leaf or Tesla motor?
If that's a 'wrong question' I'm happy to be steered down the proper path
My current understanding is that using a lower voltage pack just means the inverter has to spend more energy boosting the voltage on the high bus to achieve the desired rpm/kv. However I don't feel confident in my understanding and feel like there must be limitations I'm not aware of, ie it's not that simple.

Voltage defines the maximum speed of the motor. If you half the volts, you half the max speed.

The inverter doesn't 'boost' the volts. It chops the current so you can control torque throughout the speed range.

I think the safe limit of FW to higher RPM is 25%. So FW is to be used at the end of RPM curve. Not always. This way you are increasing motor losses and causing EMI.

Better you get motor rewound to your voltage. Leaf motor has strands of wire so stator could be rewound relatively easy.

When a motor runs it generates a opposite magnetic field.
To overcome that field (and spin the motor faster) you need more voltage....

EV_Builder wrote: ↑Sun May 23, 2021 4:58 pm When a motor runs it generates a opposite magnetic field.
To overcome that field (and spin the motor faster) you need more voltage....

Or shift the excitation vector upwards so rotor field is deducted from stator field and rotor speed can increase. But also current flow in stator increases and with it heat...