why three phase induction motor draws current with spike at low frequency by using VFD?
You have to understand an induction motor is basically a transformer with an odd rotating secondary. It has all the properties of the transformer.

What beats you here is magnetic saturation. The voltage you may apply to a given transformer primary depends linear on frequency (within the bounds of the used magnetic material). For your motor/transformer, as soon you go below 20Hz, you have to reduce the primary voltage to avoid saturation of the core.

Saturation does exactly this, during one half of the AC cycle the magnetic material cannot "eat" more voltage-time and so the current increases as it wasn't there. That's why you see those spikes. The lower your frequency drops, the longer the time per AC cycle in which the magnetic material is saturated.