A circuit breaker
is an electronic switch designed to isolate a circuit in the case of overload or short circuit. The GCB is typically installed between the generator and the main generator step-up (GSU) transformer, where the electricity leaves the generator and enters the generator circuit breaker via isolated-phase bus (device used to conduct electricity because of the magnitude of the power being transmitted). Its purpose is to create a breakpoint in the system and is typically used to protect the overall system in the event of overload or any other electrical fault.
The GCB works by automatically interrupting current flow at the onset of a fault. GCBs have two contact points, a physical connection (made up of two fixed and mobile units) and a gaseous connection, which is usually sulfur hexafluoride (SF6) gas because it is twice as resistant to the flow of electricity as air.
Power stations usually transfer electricity at very high voltages (between 72KV and 1200KV), at these voltages if contacts are simply separated; an electrical arc forms bridging the gap created and continuing the flow of electricity.
This is counterproductive as the main point of breaking the connection is to stop flow of electricity. To solve this problem, the temperature conditions and distance between the contacts has to be controlled. To achieve effective control of the arc, the separation takes place in an arc chamber filled with SF6 gas. The physical connection is designed with two parts, a permanent contact (located close to the chamber walls) and arc contact are also filled with SF6 gas. To carry out a break, the permanent contacts are separated leaving only the arc contacts. This concentrates the flow of electricity in the arc contacts. The arc contacts are then separated and a controlled electrical arc is formed between the arc contacts.
These types of circuit breakers have good dielectric strength and excellent arc quenching property. It is an inert, non-toxic, non-flammable and heavy gas. As circuit breakers are totally enclosed and sealed from atmosphere so it is very careful where explosion hazards exist.
The properties of sf6 has made it possible to design circuit breakers with smaller overall dimensions, shorter contact gaps, which help in the constructions of effective breakers. Due to the availability of several operational methodologies, generator circuit breakers are used in all applications without any hesitation. The global market for Generator circuit breaker
was estimated to be $XX billion in 2014. The global market for Generator circuit breaker market is estimated to grow at a CAGR of XX% and is forecast to reach $XX billion by 2021. The Power Generator circuit breakers are forecast to have the highest growth of XX% during the forecast period 2015-2020. Power transmission, automotive and Tele communications are the major end-users for Generator circuit breakers. North America and Asia alone are estimated to occupy a share of more than XX% during 2015-2021.
Asia-Pacific is the largest market for generator circuit breakers, owing to the increase in urbanization and industrialization in the region. It is followed by North America, which is growing due to increase in demand for power in the region.
Asia is the leading market for Generator circuit breaker Market with china leading the charge. Asia region is forecast to have highest growth in the next few years due to growing adoption of generator circuit breakers in industrial applications. Asia Generator circuit breaker market accounts to XX% of the global market for Generator circuit breakers and is the fastest growing market followed by Americas.