Ternary machine set
A ternary machine set (contains the ternary `` consisting of three basic units '' derived from the Latin numeral ter `` three times ' ' ) is a type of machine set for use in pumped storage power plants . It consists of an electrical machine that can work as a motor or generator , a turbine and a mostly multi-stage radial pump . The turbine can be designed as a Francis turbine or Pelton turbine , the machine set can be designed with a horizontal or vertical axis.
application
The ternary machine set was the usual design for pumped storage power plants until the middle of the 20th century, but was then replaced by the pump turbine, which was cheaper in terms of production and maintenance costs . Nevertheless, there are areas of application that are reserved for the ternary machine sets. They are particularly suitable for large heads , which can be better processed with Pelton turbines. Furthermore, in contrast to the pump turbine, a very quick change between turbine and pump is possible.
