Turbine Generator with Increased Rotation Speed for Small-Capacity Thermal and Nuclear Power Plants

The article considers the design of a 4.5 MW synchronous generator with increased rotation speed excited from permanent magnets as a promising application for small-capacity thermal and nuclear power plants for local heat and power supply in the Arctic region. Through a comparative analysis of various options, the rational geometric dimensions and electromagnetic loads of the generator are determined; structural, magnetic and ferromagnetic materials are selected, and the results from numerical calculations of a 2D electromagnetic field using the finite element method are presented. The generator is equipped with a forced axial ventilation system with an open cycle, which ensures the necessary thermal conditions of the machine. The generator versions with a six-phase design for the 6300 V and 3150 V voltage levels are considered. It is shown that a six-phase machine can be a good alternative to a three-phase design. The use of a generator with a rotation speed of 18000 rpm at small-capacity power plants is very effective when operating in a cogeneration cycle and features significantly lower harmful atmospheric emissions. The high rotation speed makes it possible to reduce the generator’s weight and size.