Variable Frequency AC Drives

Varitrol® is a High Efficiency Variable Frequency Drive (VFD) with Integrated Machine Monitoring and Protection System. The machine monitoring system continue monitor's machine condition  and automatically correct operating parameters of the VFD, give alarm and trip signals and protect valuable investment and expensive repairs. (US Patent pending file no. 62/532,113)

For longer motor cables Varitrol® is Offered with optional multilevel inverter output which eliminates the motor cable length restrictions imposed by other vendors.

We supply multiple AC drive systems fed from a common DC bus for pulp and paper, steel and other continue process lines.

Please download Varitrol®  brochure for more details by clicking on the link on the LHS.

 If you have a specific question please send us via contact us, we will be very much pleased to answer.

Varitrol® Variable Frequency Drives Data sheet at a Glance:

 How do we differ:

We offer following features which no one else offers:

a. We offer integrated machine monitoring and protection system (US patent pending) at no extra cost for the drives larger than 150hp.

b. We offer one extra phase for  multilevel active front end (MLAFE) for better fault tolerance.

c.  We offer one extra phase for multilevel output inverter for better fault tolerance.

Each and every Varitrol® drive is custom designed for the optimum performance of the Motor and the driven System.

Controller Type:  V/hz or Constant torque

Power Range:  3kW to 6MW

Input Voltage Range: 220-4160 Vac, 3ph, 50/60hz; or Common DC bus

Cooling Method:

Depending on the power rating and the available physical area for installation, we offer following four types of cooling:

                a. Convection cooled

                b. Forced air cooled

                c. Water to water heat exchanger

                d. Water to air heat exchanger

 Rectifier Section:

                     a. No front end rectifier.  Supplied by external DC power source  for traction applications

                    b. 6 and 12 pulse diode rectifier

                    c. Two level active front end (AFE) with smart harmonic injection for reduced or no harmonics generated into the power network.

                    d. Multilevel active front end (MLAFE) with one extra phase to provide redundancy of the power devices. If any of the input power IGBT fails, the spare phase will automatically is configured for the failed phase.

 Inverter Section:

                     a. Two level inverter section, with limited length of motor leads.

                    b. Multilevel inverter section, which eliminates the restriction on the length of the motor cables.

                    c. Multilevel inverter section with one extra phase to provide redundancy of the power devices. If any of the output power IGBT fails, the spare phase will automatically is configured for the failed phase.

 Integrated Machine Monitoring and Protection system: (US Patent pending file no. 62/531,113)

Varitrol® has six temperature and three vibration sensor (accelerometer)  inputs.   Temperature and the vibrations of the motor winding and bearing, and of the driven equipment are continuously monitored, alarm and trip signals are generated should they fall out of the set limits.

 Varitrol® will automatically avoid operation of the drive at resonance frequencies by jumping to the next safe value.