gei os circuit breaker
Based on your question "gei os circuit breaker", it is speculated that it may be a spelling error of **"Generator Circuit Breaker
(GCB)"**. The following is a detailed answer based on technical materials:
I. Clarification of Core Concepts
The **Generator Circuit Breaker (GCB)** is a high-voltage switching device specifically used to protect the generator and its power
distribution system, rather than the **GIS circuit breaker** (Gas Insulated Switchgear, used for transmission lines in substations).
The differences between the two are as follows:
- **GCB**: It directly connects the generator to the power grid and quickly cuts off internal or nearby faults of the generator to
protect the generator from damage caused by short-circuit current.
- **GIS**: It is used in high-voltage power transmission and distribution systems, integrating circuit breakers, disconnectors and
other equipment, and using SF6 gas for insulation.
II. Key Technologies and Applications of the Generator Circuit Breaker (GCB)
1. Technical Parameters and Performance
- **Rated Voltage**: Usually 10-35kV (for example, the GCB for gas turbines is 24kV).
- **Rated Current**: 6,300A to 50,000A (for large units, it can reach more than 29,000A).
- **Short-circuit Breaking Capacity**:
- Conventional type: 63kA-130kA (such as the HECS series of Hitachi Energy);
- Ultra-large type: 210kA-300kA (such as the environmentally friendly GCB developed by China XD Electric Co., Ltd., with a
breaking time of less than 40ms).
- **Arc Extinguishing Medium**:
- **SF6 Gas** (the mainstream technology, such as the HEC 9 series of Hitachi Energy);
- **Vacuum Arc Extinguishing** (an emerging technology, such as the VD4G series, suitable for scenarios below 63kA).
2. Typical Application Scenarios
| Field | Demand Characteristics | Case |
| Nuclear Power/Thermal Power | High reliability, quickly cut off short-circuit faults, and protect million-kilowatt units. | The 210kA environmentally friendly GCB of China XD Electric Co., Ltd. is applied to nuclear power and thermal power projects. |
| Gas Turbine | Adapt to low-frequency working conditions (20-45Hz) and frequent start and stop. | The complete set of 100kA GCB for gas turbines meets the requirements of 9F/9H multi-axis units. |
| Pumped Storage | High mechanical life (more than 20,000 times) and adapt to fast charging and discharging. | The GCB for pumped storage of China XD Electric Co., Ltd. has a rated current of 15,000A and a short-circuit breaking capacity of 100kA. |
| Synchronous Compensator | Large current-carrying capacity and stabilize the reactive power of the power grid. | The HVR-63 series of Hitachi Energy supports real-time monitoring of arc erosion. |
3. Technical Advantages
- **Protect the Generator**:
Quickly cut off the fault current (less than 40ms) to avoid the generator from being damaged by overcurrent and negative
sequence magnetic fields during short circuits.
- **Simplify System Design**:
Replace the circuit breaker on the high-voltage side of the "generator-transformer unit", reduce the switching operation of
the station service power, and improve the reliability of power sxt-wrap-mode: nowrap;"> Pumped storage projects require high mechanical life; gas turbine projects require low-frequency breaking capacity.
- **Brand References**:
International: Hitachi Energy, ABB; Domestic: China XD Electric Co., Ltd., Xi'an High Voltage Apparatus Research Institute.
**Conclusion**: The generator circuit breaker is a core device to ensure the safety of large generator sets. Its technical
development trends are **high capacity, fast breaking, and intelligence**, and it will continue to expand its applications in
the fields of new energy and energy storage in the future.
