Slip Energy Recovery (SER) Drives


The CSE Uniserve Rotor Drive Slip Energy Recover System (SER) is designed for speed control of wound rotor induction motors. Typical applications include mills, crushers, fans and pumps.  Designed and manufactured in Europe to CSE Uniserve’s specifications, offers the ultimate in single or dual motor speed control.
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The CSE Uniserve Rotor Drive Slip Energy Recovery System (SER) is designed for reliable and repeatable mill starting and speed control and to return all unused energy into circuit below when operating 100% speed.  It exclusively offers operators full torque at hyper synchronous speeds. Typical applications include mills, crushers, fans and pumps.  Designed and manufactured in Europe to CSE Uniserve’s specifications, the CSE Uniserve Rotor Drive offers the ultimate in single or dual motor speed control.


Grinding performance:

  • Sub and hyper synchronous Mill Motor speed control
  • Constant torque above synchronous speed (Motor shaft power above nameplate rating)
  • Performance rated at Synchronous speed (No dead band)


Electrical features:

  • Motor and System Power Factor control
  • Recovery circuit Active VAR Generation
  • Recovery transformer pre-charge (low inrush)
  • Low Current Harmonics (TCHD) Typically 3-5%


Production Performance:

  • Automatic and manual Bump-less Bi-Directional Transfer, to and from LRS providing high starting torque and redundant Mill operation via LRS (Fixed or Variable speed)
  • Bi-Directional motor rotation capability as standard
  • Frozen Charge protection via LRS
  • Fieldbus Connectivity and remote dial-in


Installation benefits:

  • IGBT Liquid to Air heat-exchange platform (transfers heat outside switchroom – minimal air conditioning required)
  • Extremely small footprint and no rear access required
    • @6MW 5400 x 800 x H 1920mm – ideal for a containerised solution
  • IP54 construction (No cubicle ventilation = zero dust load)
  • Stainless steel framed cabinets and Galvanized Plinth as standard, (fully stainless cubicle option)



  • Wide ambient operating temperature range (minus 40°C to +55°C) available
  • Altitude to 5,000m available

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Slip energy recovery system

When you have been working alongside the best in the industry for over 35 years, you learn a thing or two about the requirements of your customers and gain invaluable insights into where savings can be made and processes streamlined to maximise the return on investment of equipment. A kinetic recovery system is a good example of a product that puts otherwise waste energy to use, by recycling kinetic energy generated under braking through a process of storing it and using it later for the purposes of acceleration.

At CSE Uniserve, we have worked side-by-side with partners in Switzerland to design and manufacture the CSE Uniserve Slip Energy Recovery System (SER) Rotor Drive, which caters to speed control of wound rotor induction motors and offers the ultimate in single or dual motor control.

The SER is fully cooled via liquid, eliminating the need for air through systems, near bump-less transfers are achieved and even at above synchronous speeds, constant torque is possible. This unit has an extremely small footprint, it comes with active power factor control and there is no synchronous speed deadband. In addition to this, there is no requirement for PLC seeing as the proprietary main controller facilitates control. It has been designed for use with mills, crushers, fans and pumps.

Why you can trust our energy recovery system

At CSE Uniserve, all of our operations both at home in Australia and abroad are governed by the AS/NZS ISO9001 standard (Quality Management Systems) as part of our Integrated Management System. To this end, we have created and enforce a culture of continuous improvement throughout our organisation with some key deliverables and goals in mind that we strive toward in all our efforts. These include:

– Earning recognition from our customers based on our quality progress.

– That we will endeavour to continually improve our business processes to make the organisation more efficient and so that it is in line with the ethical demands of our customers.

– That we are in compliance with all of our contractual obligations, both in respect of regulatory and legislative requirements and are meeting our agreements where quality is concerned.

– That we will develop quality improvement goals and achieve them in the timeframes that are set.

– That we will continually strive for a complete understanding of the changing needs of our customers and monitor the changing expectations of the industry.

We are committed to leading the way in terms of best practices where quality and service are concerned, and bringing products and innovations to the industries we serve that are forward-thinking and bring about even greater efficiencies.

The best modern slip energy recovery drive (SER) or rotor drive available

When it comes to achieving the consistent and effective operation of wound rotor induction motors such as those commonly found in large mills and pumps, speed control, energy efficiency and the ability to safely drive the motor to hyper synchronous speeds are all potentially important considerations. And with the help of a Slip Energy Recovery (SER) system, you can be sure that controlling the speed of your motors can be easy, environmentally sound, cost effective and completely safe.

New technology, modern Slip Energy Recovery Drives offer much more than speed control for the single or dual motor SAG mill market.

Using this latest generation technology, designers and operators can address the key concerns of mechanical, electrical, environmental and financial stakeholders. A modern SER returns unused power when operating below 100% speed and offers full torque at hyper synchronous speeds as well as the ability to be designed for near unity or even leading power factor to offset other areas of electrical design.  Modern SER feature improved control methods and with it, the ability to be much more sympathetic to mechanical components.  Finer control of mill speeds also results in much improved grinding performance and no need to contend with a speed dead band.    Environmental and financial teams will also enjoy demonstrably reduced power consumption whilst in operation, lower emissions, and manufacturing/installation costs by virtue of its smaller physical size and vastly reduced cooling requirements than a comparable Variable Voltage, Variable Frequency (VVVF) drive.

When coupled with purpose-built SAG Mill starting Liquid Resistance Starters (LRS), the exclusive benefit of Hot Redundancy is available.  In the unlikely event the SER fails, the system will transfer control to the LRS units until the SER is reset.

Our products (such as our rotor drive) are manufactured in Europe to the highest possible standards, according to our very own specifications. This way, we can guarantee that absolutely every product we sell is the very best of its kind available. Over the years, our commitment to consistent high-quality has earned us a strong reputation as one of the world’s leading specialists in electrical products and engineering services, and we’ve come to be trusted by many companies in a great variety of different industries.

A bright future with CSE Uniserve

At CSE Uniserve, we offer 24/7 customer support to all of our clients as well as thorough and comprehensive lifetime service on all of our technologies. We achieve this through devoted onsite services and in-house technicians. Our abilities to deliver the highest quality maintenance and repair service of products as well as onsite testing, commissioning, training, site audits and preventative maintenance ensures that our client receives the best-rounded package when they choose CSE Uniserve.

We take pride in being about more than just state of the art products and equipment. We’re also proud to provide our customers with superior levels of customer service, being careful to ensure that each and every client receives all the information, help and support that they need not only to make informed purchases but also to get the most out of their new products once they arrive.

Our team of highly trained and experienced professionals can help with the installation of new systems, as well as providing ongoing operational support, periodic inspections and maintenance to ensure that everything continues to run smoothly, effectively and safely for many years to come.

Simply get in touch with a member of our friendly team to find out more information about any of the products we sell or the services we offer.

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CSE Uniserve MV & HV Portfolio Brochure – Published Version

CSE Uniserve Capability Statement

Product Overview – Published Version


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