Speed control

VFD (variable frequency drive).

But in an old plant we are using resistors in rotor I said it improve torque not speed, we should use VFD OR EMF injuction method.The industry have lot of 5 HP indn. Motors. The industry is always overburdened of electricity bills.Can i make a drastic change in electricity bill by implimenting VFD.

The mechanical load determines the torque the motor experiences.

<...Can i make a drastic change in electricity bill by implimenting VFD....>

It depends upon the tariff charged.

VFD and two sinding speed motor

Sir, sinding speed motor ? VFD how much it cost for 5 HP motor we want an efficient solution for speed and torque proportional as in vehicle gears.

Sir, Give me a solution for control of induction motor as 4 gears in a car ( speed and torque ). We are using resistance cutting step by step inorder to get speed and torque. 1st gear less speed maximum torque and in 4th maximum speed less torque. I can shine for a new idea. 5HP 3PH INDUCTION M.

A 5HP VFD can provide full rated motor torque from basically 0 RPM up to full rated RPM and maximum HP rating. The drive can also run the motor above rated speed (at reduced torque and HP). In all cases, motor temperature rise must not exceed maximum rating or damage will occur.

There are many online sources for Variable Frequency Drives and I can see several 5 HP 220V (or 440V) 3 phase GE drives starting at US $220. This will be the easiest and most efficient way to fully control your motor.

Good luck with your project.

Give me a solution for control of induction motor as 4 gears in a car .

VFD with regeneration for maximum system efficiency. That you must be looking on for your project.

Some Idea is here as I quickly scanned net. But you have to do a bit more research before you solidify your idea. After all that's why the projects are put into curriculum .

_{BTW: 5HP is a small end motor for industries.}

A senior electrician said only squirrel cage induction motor can be VFD controlled not slip ring is it true?