Starters and variable speed drives for slip ring motors

Since 1984, Electrodrives has been a pioneer in Liquid Resistance Starters (LRS) and Slip Energy Recovery drives (SER drives) for slip ring motors.

Today, our large experience and cuting-edge designs make us the industry leader, offering the most sophisticated solutions on the market.

Why Slip Ring Motors? The Hidden Advantage

Slip ring motors, often overshadowed by their more common counterparts, have a number of advantages that make them the ideal choice in several industrial applications.

Superior Starting Capabilities: Unlike standard motors, slip ring motors offer high starting torque with low starting current. This means smoother starts, less stress on your system, and a longer lifespan for the motor.

Unmatched Energy Efficiency: Combining the motor with a Slip Energy Recovery drive (SER drive), the system reaches the highest efficiency achievable for electrical motors in variable speed applications, as the SER drive is capable of recovering the slip energy from the motor and effectively redirecting it back into the grid.

Durability in Harsh Conditions: Built to withstand tough environments, these motors are less susceptible to wear, and tear compared to others. This resilience translates to fewer downtime.

Discover our range of products

RotorProtek®

Control and protection device for wound rotor motor with advance communications
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FlexStarter

Second generation of liquid resistance starter for wound rotor motor with speed and torque control
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HyperDrive

Slip Energy Recovery drive design to control the wound rotor motor speed in constant torque applications

RecoveryDrive

Slip Energy Recovery drive design to control the wound rotor motor speed in quadratic torque applications

Energy management systems

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Electrodrives design and manufactures the necessary equipment to balance the reactive power and power quality requirements to comply with IEEE 519 recommendation in your plant. This includes:

  • Fixed Medium Voltage Capacitor Banks
  • Multi-Stage Automatic Medium Voltage Capacitor Banks Static Var Compensation (SVC)
  • Static Var Compensation (SVC)
  • Medium Voltage Harmonics Filters

Latest News

A recently installed LRS unit positioned on-site within a mining environment, connected to a high‑power Slip Ring Motor system. The enclosure and cabling appear fully mounted, with the RotorProtek protection and control architecture integrated into the start-up circuit for stable and controlled motor torque
03/02/2026

Electrodrives strengthens operational reliability in the Birimian Belt of West Africa

The Electrodrives team successfully completed the installation and commissining of a new LRS (Liquid Resistance Starter) designed for the controlled start‑up of a 4.3 MW motor at a major mining complex located in the Kédougou region, in the heart of the Birimian Belt—one of the most significant gold‑producing areas in...
28/01/2026

Largest deployment of RotorProtek in a single mining plant in Peru

More than 15 months of RotorProtek operation More than a year ago, the largest deployment of RotorProtek — Electrodrives’ advanced solution for the protection and control of wound rotor motors — was carried out, with 8 units installed in a single intervention at a high‑altitude copper mine in Peru. In...
SER Drive de alta potencia para motores de anillos rozantes en aplicaciones de molienda minera
22/01/2026

Electrodrives validates SER and LRS systems to ensure operational continuity in a mining project in Canada

High‑demand FAT for operational risk reduction In mining operations where unplanned shutdowns significantly impact production and cost, validating the actual operating behaviour of starting systems is critical for the mine’s peace of mind. Electrodrives has successfully completed the Factory Acceptance Tests (FAT) for both its 6,100 kW SER Drive system and...
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