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Variable Frequency Drive Triol AT27 line MV

Medium-voltage Variable Frequency Drive Triol AT27 line MV is an extremely reliable solution for general industrial use in a wide range of operating temperatures (up to +60°C), in conditions of high dust content including conductive dust and moisture. The drive rated power ranges from 200 to 4000 kW.


Triol AT27 VFD line MV operates in harsh operating conditions that are achieved due to the increased IP65 enclosure with a dual-circuit cooling system. Heat is removed from the power unit through air-to-air heat exchangers using fans. Triol AT27 VFD line MV is a cabinet-type drive for both outdoor and indoor installation The model range of this line includes a number of versions depending on the rated input voltage, rated motor voltage, rated power.

  • Operating temperature maximum range -60 ºС…+60 ºС  (-76 ºF…+140 ºF)
  • Outdoor, for maritime climate and high conductive dust concentration
  • Enclosure NEMA4 (IP65) or NEMA4x
  • Minimum constructing and installation costs.
  • No costs for HVAC system
  • Maintenance-free
  • Color touchpad 7”
  • Wi-Fi Wizard
  • Induction and synchronous motor
  • Output voltage and current sinusoidal
  • High power factor ≥ 0.96
  • Operating in unstable mains
  • Build-in output filters
  • Custom designs


Input voltage, kV3; 3.3; 4.16; 6; 6.3; 6.6; 10; 11 (-15 % …+10 %)

-45% continuous with power limit

-100% not less than 100 ms with controlled generator mode of the motor

Input frequency, Hz50 / 60 (-10 %…+10 %)
Power, kW3 / 3.3 kV

4.16 kV

6 / 6.3 / 6.6 kV

10 / 11 kV

from 160 kW up to 2000 kW

from 160 kW up to 2000 kW

from 200 kW up to 2000 kW

from 320 kW up to 2000 kW

Power factor0.96
THDi (input current), %< 5
Pulses of rectifier18; 24; 30; 36; 48; 54

(depends on the number of cells in each phase)

Overvoltage protectionSurge arresters


Rated output voltage, kV3.3; 4.16, 6; 6.6; 10; 11
Output frequency, Hzfrom 0.5 up to 120
Frequency resolution, Hz0.01
Output current, A25…480
Overcurrent characteristics120 % of rated value for 120 sec

150 % of rated value for 3 sec

THDi (output current), %< 2
THDu (output voltage), %< 5
dV/dt value< 1000 V/μs
Efficiency, %≥ 96


Copper transformerCopper bus is the material used for transformer windings. Transformer parameters and efficiency are commensurable with the basic type of transformer with windings of aluminum busbars.
Mechanical bypass of power cellsBypass of each power cell of the drive is made on the basis of a vacuum chamber, with a response time of not more than 4 msec.
IGBT bypass of power cellsBypass of each power cell of the drive, made on the basis of IGBT transistors.
Additional power cell in each phaseFor compensating voltage drop on the output sine-filter or reactors (if available) and the long cable line, as well as to ensure operation in the nominal mode in the case of bypassing the cells (with this option).
Increased protection degree Enclosure NEMA4x 
Alternative range of operating temperatureOperating temperature from minus 60 ºС to plus 40 ºС
Bottom cable entryOrganization of terminals for entry power and signal cables on bottom of the AT27.
Additional PCB coverageCoating of printed circuit boards with a special varnish to protect against aggressive impurities in the air.
Electromagnetic door lockElectromagnetic locks on the doors of the AT27 power compartments provide protection against opening doors when medium voltage is applied.
Reactors for transfer of the motor to mainsDesigned to provide synchronous and shockless transfer of the motor to mains.
Sine-filterDesigned to improve of the output current and voltage THD, as well as reduce the value of the parameter dV/dt.
Medium-voltage switch compartmentAllow you to implement the required one-line diagram.

Built-in option or external cabinet is defined upon request.

Profibus communication protocolConvertor Modbus-Profibus