Description：

This product is suitable for water, thermal power, and nuclear power units with a single generator capacity of 600-800 megawatts. The rated short-circuit breaking current is 160 kiloamperes, and the rated peak withstand current is 440 kiloamperes. In 2013, it was appraised by the China Machinery Industry Federation and successfully applied in the Xiangjiaba project, achieving complete localization, making China one of the few countries in the world capable of producing large capacity generator circuit breakers, and reducing engineering procurement costs for domestic users.

Product Performance:

• Implemented according to the latest IEC standards.

• High insulation level: meeting the insulation requirements of the products under the environment of 3,000m above sea level.

• High long-term flow capacity: adopts natural cooling, no auxiliary heat dissipation device, the rated flow capacity up to 25,000A. With forced air cooling by fan, the rated flow capacity up to 27,000A.

• Excellent 0breaking performance: the effective value of Ac component of short-circuit breaking current has is 160kA and the DC component is as high as 87%, which meets the current breaking requirements under various fault conditions.

• High mechanical reliability: Innovative design of circuit breaker drive ensures that the product can meet the breaking performance under the small input operation power, and realize the mechanical life requirement of operation for 5,000times, Disconnector and earthing switch meet the mechanical life requirement of operation for 10,000 times.

• Comprehensive safety protection measures: Pressure release device is installed at the top of the circuit breaker. When the gas pressure in the arc extinguishing chamber exceeds 1.2MPa due to an accident, the gas will be released to ensure the safety of the personnel and surrounding equipment. The product design can ensure the stable operation of the power plant.

Product Structure:

• The product consists of three single poles, and each pole has an individual enclosed metal enclosure mounted on the same chassis.

• Circuit breaker is equipped with hydraulic spring operating mechanism; The disconnector and earthing switch are equipped with motor operating mechanism; The driving modes are all three-phase mechanical linkage.

• Each operating mechanism is installed on the side of the product close to the control cabinet.

• SF6 is used as internal insulation and arc-extinguishing medium for circuit breaker, and adopts self-energy arc extinguishing principle. It is mainly composed of the main contact system, arc extinguishing system and driving system.

• Air is used as insulation medium to isolate the break of the disconnector, the isolation moving contact adopts telescopic direct-acting structure, and the fixed contact adopts inner and outer two-layer contact finger structures, when closing, both the inner and outer surfaces of the moving contact are in contact with the contact finger, thus ensuring sufficient current capacity. Double guiding devices are used to ensure smooth closing of the moving contact.

• Air is used as insulation medium to isolate the break of the earthing switch. The fixed contact is installed on the support of the main circuit, and the moving contact is installed on the bottom plate of the single pole enclosure.
  

Typical applications:

160kA intelligent generator circuit breaker：

160 kA intelligent generator circuit breaker not only has basic protection function, but also integrates potential transformer, current transformer, lightning arrester and other components. Each product is equipped with a set of intelligent on-line monitoring device to realize on-line monitoring of conductor temperature, mechanical characteristics of circuit breaker, SF6 gas condition and so on.
Main technical parameters:

What are the technical parameters of generator circuit breaker？

Rated Voltage:

• This is the highest voltage at which the generator circuit breaker can operate normally. For example, for generator circuit breakers in large thermal power plants, the rated voltage may reach 20 - 30 kV or even higher. This parameter must match the rated output voltage of the generator to ensure safe and reliable operation under both normal and fault conditions.

Rated Current:

• It indicates the maximum current that the generator circuit breaker can carry continuously. The selection of the rated current should be based on the rated capacity of the generator. For instance, a 100 MW generator may have a rated current in the range of several thousand amperes, and the rated current of the generator circuit breaker needs to meet this requirement to ensure it can handle the generator's output current during normal operation.

Short-Circuit Breaking Capacity:

• This is a critical parameter that measures the ability of the generator circuit breaker to interrupt short-circuit faults. When a short circuit occurs at the generator outlet or on the grid side, the circuit breaker must be able to quickly interrupt the high short-circuit current to prevent the fault from spreading. For example, in large power plants, the short-circuit breaking capacity of the generator circuit breaker may reach tens of kiloamperes or even higher, requiring the breaker to have strong arc-quenching capabilities and good thermal and dynamic stability.

Making Current:

• The making current refers to the maximum instantaneous current that the circuit breaker can withstand when it is closed. During generator startup or when the grid recovers after a fault, there may be significant inrush currents. The circuit breaker must be able to safely close these currents; otherwise, it could result in issues such as contact welding.