Main circuit equipment for hydro and pumped storage plants: generator circuit breakers, busducts, SFC, excitation transformers
A package of auxiliary electrical equipment (balance of plant) for hydro and pumped storage plants, formed on the basis of the overall electrical design of the station. It includes generator circuit breakers, isolated phase busducts, disconnectors, excitation and station service transformers, low-voltage switchgear and a static frequency converter (SFC). The package is supplied together with the main hydro units or for plant reconstruction.
- Main circuits
- generator circuit breakers, isolated phase busducts, disconnectors, phase reversing disconnectors
- Excitation
- excitation transformers
- Pumped storage start
- static frequency converter (SFC)
- Station service
- station service transformers, LV switchgear
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
The generator circuit breaker switches the generator circuit between its terminals and the step-up transformer. It interrupts a short circuit on the generator side, and the unit is synchronised with the grid at generator voltage, while the step-up transformer remains energised and feeds the station service loads. The generator is connected to the breaker and the transformer by isolated phase busducts, in which each phase has its own enclosure. The screening limits electrodynamic forces between phases and practically excludes a phase-to-phase short circuit in the busduct itself. The main scheme also includes disconnectors, and for pumped storage plants phase reversing disconnectors. They change the phase sequence when the motor-generator passes from generating to pumping mode, because in pumping mode the machine rotates in the opposite direction.
Excitation transformers feed the generator excitation system. Station service transformers and low-voltage switchgear feed the equipment of the station itself. The static frequency converter (SFC) performs the frequency start of the pumped storage motor-generator into pumping mode, that is, it accelerates the unit from the grid through the converter to synchronous speed before connection.
Supply to a single design makes it possible to match the main scheme parameters, short-circuit currents, start and protection modes with the characteristics of the hydro unit, and also to shorten installation times. Technical characteristics of individual apparatus are not given in the manufacturer's materials; they are determined by the plant design. The rated current and breaking current of the generator circuit breaker, the current and design of the busduct, the rating of excitation and station service transformers, and the SFC rating are selected for a particular hydro unit, its rated voltage and the power evacuation scheme.
The manufacturer designs and supplies the main equipment of hydro plants, Francis, Kaplan, Pelton, Deriaz and bulb turbines, and for pumped storage plants motor-generators of constant and variable speed. Therefore the auxiliary main-circuit equipment is agreed with the main machines within one project. The package is used at new hydro and pumped storage plants and in reconstruction of the electrical part of stations, when generator circuit breakers, busducts and starting devices are replaced. To form the package the customer provides the single-line diagram of the station, the parameters of the hydro units and step-up transformers, and the power system requirements for station operating modes.
Technical specifications
| Main circuits | generator circuit breakers, isolated phase busducts, disconnectors, phase reversing disconnectors |
|---|---|
| Excitation | excitation transformers |
| Pumped storage start | static frequency converter (SFC) |
| Station service | station service transformers, LV switchgear |
| Supply | as a package per the plant design |
Request a price and lead time
Main circuit equipment for hydro and pumped storage plants: generator circuit breakers, busducts, SFC, excitation transformers. We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Questions and answers
Why is a phase reversing disconnector needed at a pumped storage plant?
It changes the phase sequence when the motor-generator passes from generating to pumping mode.
How is the pumped storage motor-generator started into pumping mode?
The package includes a static frequency converter (SFC) for frequency start into pumping mode, which accelerates the unit before connection to the grid.
What parameters do the generator circuit breakers and busducts have?
Technical characteristics of individual apparatus are not given in the manufacturer's materials. They are determined by the electrical design of a particular plant.
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