Technical reliability – our promise to you
Our products and services are designed specifically for your needs. Always efficient and economical and, above all, following our values and visions for sustainable hydropower solutions. We offer generator solutions for all ranges of speed, for horizontal and vertical designs, for fixed-speed and variable-speed applications and with air-cooled as well as water-cooled windings. All Voith generators are designed and manufactured with the latest state-of-the-art technology including the use of Vacuum Pressure Impregnation (VPI) for the stator bars and coils. Rated voltages up to 25 kV are part of our standard production.
History of generators and motor generators
Power demand is increasing with the expansion of the economy and improved living standards. Following this trend, the capacity of generating units has also increased, growing from 6.25 MVA at Necaxa in 1903 up to 840 MVA at Three Gorges in 1997 and now to more than 855.6 MVA at the Xi Luo Du and even 944.5 MVA at the Wu Dong De power station. These are the most powerful generators designed and manufactured by Voith today.
Know-how from a full-line supplier
Since the early 20th century, Voith has manufactured motor generators. We offer technical excellence in synchronous as well as asynchronous generators.
Our technology features include:
- Excitation, static frequency converters (SFC) and SCADA systems
- Well advanced and proven VPI insulation system for optimized design for Class 155 according IEC (formerly Class F) and voltages up to 25 kV
- Air-cooled by RIM-ventilation or forced ventilated, or direct water-cooling of stator winding and/or rotor winding and/or stator core
- Magnetic thrust bearings for reduced torque during pump starts and reduced bearing losses during normal operation
- Comprehensive system for automation of power station complex as a whole, including monitoring, remote supervisory control and data acquisition of the plant with fiber optic cable as required for control and station networks
- Static frequency converter systems composed of computer duplex digital controller and optical thyristor of high-resistance voltage for high performance and easy maintenance
With the use of an asynchronous motor generator (Doubly Fed Induction Machine – DFIM) or with synchronous machines connected to a converter, the rotational speed of the pump turbine can be varied. Thus, the pump capacity can be adjusted to using just the currently available amount of energy. This allows a highly efficient stabilization of the grid.
Since the mid-1950s, Voith has supplied bulb generators with new designs approaching high outputs in excess of 80 MVA. As bulb units grew in size, generator voltage also grew from the initial 3.3 kV and 6.6 kV to 11.0 kV and even 13.8 kV on higher capacity units. Cooling systems evolved from separate heat exchangers to maintenance-free closed loop systems, providing heat dissipation directly into the river water passing the bulb unit. For very high capacities and high speed units, pressurized air can also be used to improve heat dissipation.
Thanks to our long-standing experience in the development and production of generators, we are able to perfectly integrate them in your power plant – and optimize the energy yield accordingly. The electric, mechanical and thermal stresses are extraordinarily high in the field of hydropower. This is why we have developed our own range of hydropower generators with a robust generator design and a perfectly coordinated modular setup of the stator and rotor.
Micalastic insulation for hydropower generators
The common characteristics shared by all types of Micalastic insulation are the use of inorganic fine mica tape as a base material and heat-curing synthetic epoxy resins as a bonding material. This, coupled with state-of-the-art manufacturing techniques, provides high dielectric breakdown strength, long-term resistance to electrical stress, and a low power factor (tan δ). The mechanical properties of the tape and resin combination also provide excellent resistance to mechanical and thermal stress and different environment conditions in indoor or outdoor installations, e.g., hydroelectric power plants, pumped storage plants and substations. The Micalastic insulation system is based on Vacuum Pressure Impregnation technology and meets Thermal Class 155 (IEC)/Class F (IEEE) standards.
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HyService and modernization – keep your energy flowing
Voith offers comprehensive and tailor-made first-class service and modernization solutions. We are your partner to extend the lifetime of your hydropower plant at any point of its life cycle. And we want to keep it running smoothly. As an experienced service partner, we support you in any part of the plant’s operation. Reliable. Experienced. Available all around the world.READ MORE ABOUT HYSERVICE READ MORE ABOUT MODERNIZATION