24 kV generator circuit breaker set for pumped storage plants (GCB 13.5–18 kA, starting, braking and phase-reversal disconnectors)
The 24 kV generator-voltage switchgear set is assembled for the terminals of reversible motor-generators of pumped storage power plants. The generator circuit breaker is rated 13,500 or 18,000 A and a breaking current of 100 kA. The set performs all switching between the generating and pumping modes of the unit.
- Rated voltage
- 24 kV
- GCB rated current
- 13,500 / 18,000 A
- Breaking current
- 100 kA
- Making current (peak)
- 275 kA
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
Pumped storage plants shave peaks and fill load valleys, regulate frequency, operate as synchronous compensators and emergency reserve, and smooth the impact of renewables on the grid. The units often change from generating to pumping mode and back, so specialised apparatus is needed at the generator terminal. A standard configuration was proposed for this purpose, similar to sets of generator circuit breakers and phase-reversal disconnectors for pumped storage plants with motor-generators. The set is installed at the terminal of each reversible unit, between the motor-generator and the step-up transformer.
The set includes the generator circuit breaker GCB, an electrical braking breaker, a starting-mode disconnector, a phase-reversal disconnector, busbar disconnectors with earthing switches and an intelligent monitoring system. Through the starting disconnector a static frequency converter or an adjacent unit is connected in a back-to-back scheme. The phase-reversal disconnector changes the phase sequence when switching between generating and pumping modes. All apparatus are combined into one integrated set with a modular design and digital control; they are convenient to install and maintain and have a long service life.
The generator circuit breaker is rated for a rated voltage of 24 kV and a rated current of 13,500 or 18,000 A. The rated breaking current is 100 kA, the short-circuit making current is 275 kA peak, the short-time withstand current is 100 kA for 3 s, and the peak withstand current is 300 kA. Mechanical endurance is 20,000 operations, and electrical endurance is 8 interruptions of the rated short-circuit current. The one-minute power frequency test voltage is 65 kV to earth and between poles and 80 kV across the isolating gap. The lightning impulse is 125 and 150 kV respectively. The electrical braking apparatus is rated 24 kV and 8000 A. The insulation levels of 65/80 kV and 125/150 kV are the same for all apparatus of the set.
The set raises the protection level of generators and step-up transformers and the safety of the unit, and reduces plant operating costs. The monitoring system tracks the condition of the apparatus at the generator terminal. Besides pumped storage plants with reversible units, such apparatus is installed at hydropower and thermal power plants, where the generator circuit breaker stands in the generator-transformer circuit.
Technical specifications
| Rated voltage | 24 kV |
|---|---|
| GCB rated current | 13,500 / 18,000 A |
| Breaking current | 100 kA |
| Making current (peak) | 275 kA |
| Short-time withstand current | 100 kA / 3 s, peak 300 kA |
| Mechanical endurance | 20,000 operations |
| Insulation | AC 65/80 kV, LI 125/150 kV |
| Braking disconnector | 24 kV, 8000 A |
| Composition | GCB, electrical braking breaker, starting and phase-reversal disconnectors, busbar disconnectors with earthing switches, monitoring system |
Request a price and lead time
24 kV generator circuit breaker set for pumped storage plants (GCB 13.5–18 kA, starting, braking and phase-reversal disconnectors). We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Customs codes
| UKTZED (Ukraine) | 8535 21 00 00 |
|---|---|
| HS, 6 digits | 8535 21 |
| CN (EU) | 8535 21 00 |
| HTSUS (USA) | 8535 21 00 00 |
| China customs tariff | 8535 21 00 00 |
Codes are for reference: the final code is determined at declaration for the specific model.
Questions and answers
What parameters does the generator circuit breaker of the set have?
Rated voltage 24 kV, current 13,500 or 18,000 A, breaking current 100 kA. Short-circuit making current 275 kA peak, peak withstand current 300 kA.
What are the starting and phase-reversal disconnectors in the set for?
The phase-reversal disconnector changes the phase sequence when the unit changes from generating to pumping mode and back. The starting disconnector connects a frequency converter or an adjacent unit in a back-to-back scheme.
Is the set used outside pumped storage plants?
Yes, 24 kV generator circuit breakers are also installed at hydropower and thermal power plants between the generator and the step-up transformer.
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