Power Factor Control

Versa Drives with low harmonics

Versa Drives can supply drives with Power Factor Control (PFC)  front end for applications that require strict adherence to European Union norms (EN 61000-3-2) for domestic use.

These drives can operate from universal power supply of 110/200V single phase. An offline equipment such as a VFD which employs a rectifier-capacitor front end draws current in narrow pulses (bottom left figure) at the peak of the input voltage waveform. This results in the equipment having a low power factor, and correspondingly high harmonic currents which do not do any useful work. The low power factor results in high rms line current and the mains supply is not fully utilized.

Active PFC with boost topology is compact and corrects the power factor to near unity. Versa Drives with active boost PFC front end have several advantages.

  • Harmonics are reduced to negligible levels and EN 61000-3-2 specs are met
  • A single drive + motor combination canwork universally as the boost topology permits the drive to work with 90Vac – 260Vac range
  • Power factor is corrected to near unity and as a result the mains supply can be utilized to its full rating

The DC bus voltage is now regulated and hence the motor performance is unaffected by variations in mains voltage

The figures shown here were taken from the different models of Versa Drives. On the left are for a drive without PFC and the figures on the right for a drive with PFC. Note the near vanishing of harmonics and the smooth current wave shape in the drive with PFC front end.

In the picture is an open frame drive that has PFC with Class-B filter for meeting strigent EMI/EMC norms.


General Specifications

General Specifications for Variable Frequency Drives

The list below is only indicative but not an exhaustive one. We can customize the drive to match your requirements using features from the list or with new ones you may propose. Click here to download general information.

Parameters Range/Characteristics
Control method Linear V/f or Quadratic V/f or Sensor-less vector
Input voltage 110/220V ac 1 phase or 230/415V ac 3 phase, 50/60Hz
Output Voltage 230/415V ac 3 phase
Motor power 0.04 to 4 kW
Drive direction Over voltage
Under voltage
Over current
Over temporature
Thermal overload
Short circuit
Earth fault
Communication RS232/RS484/CAN
Display LED seven segment / LCD alphanumeric
Keyboard Up to 8 keys
Digital inputs 10-30 Vdc optically isolated
Analog inputs 0-10V or 4-20mA, optically isolated
Digital outputs Relay or Transistor
Analog outputs 0-10V or 0-5V or 4-20mA
Custom Designed Variable Frequency Drives


At Versa Drives, we make custom designed variable frequency drives suitable for Original Equipment Manufacturers (OEMs). The advantages of using Versa Drives are:  

  • Flexibility of using ACIM, BLDCM, or PMSM
  • Inputs/outputs as required
  • Application specific control functions
  • Advanced user interface features
  • Power factor correction
  • Conformance to mandatory standards
  • Adaptability to working environment
  • Desired size & shape
  • Economical

These drives, as they are also called as AC drives, AC inverters, variable speed drives, adjustable frequency drives, can be used with following types of motors,

  • AC induction,
  • BLDC and
  • PMSM.

Our customized Variable Frequency Drives or AC drives are designed to meet your needs. You may specify your drives requirement  in terms of the motor type, load, voltage, inputs, outputs, both digital and analog, communication options, annunciators, display and keyboard. Alternatively, you can describe your machine-functions to us, and we can propose a suitable system for you. We can design your drive to comply your needs in terms of performance, cost,  size & shape and standards. Ask us for a proposal.

Using hand-held unit VMP, it is easy to copy, download parameters, that too without powering on the drive. Saves time in setting up multiple units.

Size and Shape

Drives that match the space

A compact 100W inverter in two versions: one for DINRAIL mounting and screw mounting. Typically several hundred inverters are installed in a machine and the size & shape are help the customer keep the machine size small.



Drives with Power Factor Control front end to suit the space available in the machine for mounting with easy connections. The body of the machine was used for additional heat sinking capability.


Speed control: One drive with potentiometer for speed control and another drive with standard interface having display & keyboard.  



ISO 9001:2015 Logo