How to choose a medium voltage VFD: Application requirements

The requirements of your application are key when selecting suitable VFD. If you check the websites of leading medium voltage VFD manufacturers you will find several products with different performance data. Why? Several topologies are available on the market and each fits for specific applications. There is no such ‘one-fit-all’.

As example, rolling mill drive in a steel plant will have completely different requirements than a large turbo-compressor drive. The first one requires high dynamics, heavy duty overloads, eventually active front end with regenerative braking and a special inverter duty motor. The latter one is high power application with low dynamics. Active braking is usually not required and diode front end will provide lower cost and higher efficiency. VFD shall be motor friendly as the motor is located in hazardous area.

Examples of VFD applications:

– Compressors

– Conveyors

– Crushers

– Cutters

– Extruders / Mixers

– Fans and blowers

– Grid simulators

– GT starters

– Kiln drives

– Marine propulsion

– Mine hoists

– Pumps

– Rolling mills

– Shaft generators

– Starter-Helper

– Test stands

You don’t find a VFD topology that would cover everything. But you shall find several products fitting your specific needs.

Therefore, write down your requirements to make it clear what kind of product you are looking for. To learn about other important decision criteria just follow this series.