Three-phase motors

Our synchronous and asynchronous machines are distinguished by their high energy efficiency. The motors are reliable, safe to operate and robust. With our three-phase motors we offer special machines for almost any application. They are designed and built for the specific requirements of the respective drive application. We offer individually adapted motors – both in terms of electrical layout and mechanical design.

We provide made-to-measure units, for example, for existing foundations or special bearings to absorb additional forces. The power network conditions on site are taken into account for the electrical layout to ensure that only minor voltage drops occur and a reliable run-up is guaranteed. Our portfolio comprises asynchronous motors with cage or slip-ring rotors as well as synchronous motors with brushless or static excitation.

LDW supplies asynchronous motors with an output range of approx. 1,000 to 35,000 kW, and synchronous motors ranging from 4,000 to 50,000 kW.

Other features of the motors:

  • Three-phase motors for voltages up to 15 kV, output up to 35,000 kW and constant speed
  • Three-phase motors for voltages up to 10 kV at the converter, output up to 50,000 kW and variable speed
  • All prevalent types of construction, cooling and protection
  • Special types of cooling such as fluid jacket cooling up to outputs of 10 MV
  • Variants for explosion endangered areas of zone 1 and zone 2 in protection classes Ex “px” and Ex “pz” for pressurised enclosures. Increased safety Ex “e” and protection class Ex “nA” in accordance with ATEX Directive 2014/34/EU, IECEx Scheme and IEC/EN 60079 ff series of standards

For the electrical layout we take into consideration special requirements concerning a reliable start-up current as well as possible voltage drops. In this respect we always aim for a design to optimise efficiency.

Our synchronous motors are completed by an optimally adapted exciter system which we also supply with motor protection on request. This ensures a high drive dynamics. They are safe to operate and have a long service life. Three-phase motors up to and including an axle height of 900 mm we manufacture with a patented tubular housing that reduces magnetic noise and vibrations. This makes additional sound-proofing measures superfluous. The running smoothness results in high operational safety for the entire drive system.

Other benefits of the motors:

  • Individual design taking the power network conditions into account
  • Adaptation to existing foundation (retrofitting)
  • Symmetrical ventilation of active parts and winding, resulting in uniform warming and a longer service life of the machine
  • High quality VPI-type insulation system for operational safety and a long service life
  • Easily accessible and replaceable parts for exciter machine for short downtimes in the event of damage
  • 24-h service through our qualified technicians

Our three-phase motors are durable, easy to maintain and have high efficiency levels. This makes them exceptionally effective. Our motors are produced in all standard types of protection, for indoor as well as outdoor installation.

Our machines can be variously equipped, for instance with an air-air or air-water cooler. They are designed for various applications. Even for difficult applications and environmental conditions we manufacture the machines to match these conditions perfectly. In aggressive environments suitable materials are used to prevent more intensive corrosion. We provide technical solutions for motors with a fixed speed on the network (up to 15 kV, start-up with choke or start-up transformer), but also motors for variable speed operation (up to 50 MW at 1,500 rpm) and power supply by means of all standard converter types and makes. LDW manufactures synchronous motors with brushless excitation as standard. On request, we also supply variants with brushes however.

If required, our technicians will design the motor bearings for additional axial or radial loads, for example. This also applies to three-phase motors with inclined positions (roll and pitch) which are required by the responsible classification societies. We construct our motors with cutting-edge FEM tools. The design, construction and manufacture of the motors is carried out in accordance with a sophisticated and comprehensive quality assurance and protection system based on our certification according to DIN ISO 9001.

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Our AC Motors are used in the following applications amongst others: