Vertical hydro-generators from single units to hundreds of MVA

Description

Hydro-generators are three-phase synchronous machines with a vertical shaft, designed for the power and rotational speed of the turbine of a specific hydropower plant. The company combined the hydro-generator production of two founding companies; according to published data, total deliveries exceed 1,700 machines with a combined capacity of more than 78,000 MVA. Design. The generator consists of a stator with a three-phase winding, a salient-pole rotor, a thrust bearing and guide bearings, and upper and lower spiders. Particular attention is paid to the thrust bearing: the manufacturer calculates it with its own thermo-elastohydrodynamic (TEHD) analysis program, covering three-dimensional flow and temperature of the oil film, heat transfer into the segment and its deformation. Instead of traditional babbitt, segments with a PEEK (polyetheretherketone) coating are used, which offer high strength at elevated temperatures, wear resistance and self-lubrication; this reduces losses and simplifies maintenance. Range. Examples of supply: Nam Ngiep 1 hydropower plant (Laos), 162,000 kVA at 214 rpm; Chingshan hydropower plant (Taiwan), 115.5 MVA at 360 rpm; Kanagawa, 7.45 MVA; the small Toya hydropower plant, 2 × 3,600 kVA with air cooling. One of the founding companies supplied the Guri II hydropower plant (Venezuela) with a generator of 805,000 kVA at 112.5 rpm, the largest air-cooled machine at that time. Modernization. When equipment is replaced, the manufacturer evaluates the residual life of the stator winding insulation and the condition of the core, and offers rewinding, replacement of bearings with PEEK-coated segments, and a transition to air cooling without a cooling water system. Applications: new hydropower plants of all capacities, complete hydro-units with turbines, and replacement of generators at existing stations. Geography of generator supply by the founding companies: Japan — more than 33,000 MVA; North America — more than 8,000 MVA; Latin America — more than 13,000 MVA; Europe, the Middle East and Africa — more than 3,000 MVA; Asia and Oceania — more than 19,000 MVA.

Technical specifications