- #1

artis

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1) is it true that for a 50 or 60hz induction motor maximum torque is achieved from 0hz up to design hz and if an VFD is used and frequency is increased above 50 or 60hz like 100hz the rpm will increase but the available torque will decrease?

Is the reason behind this the fact that the motor stator coils are wound with the number of turns that are fixed for a fixed frequency so going beyond this frequency decreases the current that can flow through the coils and so the B field is weaker and results in less torque?

The same rule must apply to all inductors, so my next question is this

2) the same must apply to transformers as if a transformer has a fixed winding ratio then increasing the primary frequency above certain point would result in lowered current in the primary and lower B flux in the core resulting in lower secondary voltage/current?