Dual power automatic transfer switch development, national electrical switch factory, www.jiandq.com
One, dual power automatic transfer switch ( ATSE ) development process
ATSE dual power automatic transfer switching equipment, comprising a ( or several ) switch electrical appliances and other necessary appliances ( controller ), for monitoring a power supply circuit, and one or several load circuit from a power supply conversion to another power switch electric appliance. ATSE as fire load or other important load end mutual-input unit, so that load in the normal power supply, emergency power to choose between, and automatically switching the power connections, is widely applied in engineering. The correct and reasonable selection of ATSE in important loads in the power distribution system is one of the key problems.
ATSE in China has experienced four stages of development, namely the contactor, breaker type, type and double throw type load switch. The contactor switch for the first generation, is China's first production of double the power switch, which is composed of two sets of AC contactor and mechanical and electrical interlocking device, this device because of the mechanical linkage is not reliable, big power consumption and other shortcomings, in the project less used. Circuit breaker type switch for the second generation, is our national standard and IEC standard called CB ATSE, which is composed of two sets of circuit breakers and their mechanical and electrical interlocking device, having a short circuit and overcurrent protection function, but not reliable mechanical interlocking. Load switch type switch for third generations, it is composed of two sets of load switch and a built-in linkage mechanism combination, a chain of mechanical reliability, converted by the electromagnetic coil to generate attractive to drive the switch, speed. Double throw type switch for fourth generations, it is driven by an electromagnetic force, the built-in mechanical connection state, single-pole double throw switch integration, has the advantages of simple structure, small volume, its chain, fast conversion speed, safe and reliable, is a class PC ATSE.
In two, CB level and PC level, ATSE distinction
1 two different mechanical design concept. Switching on device for double power switch, and is not used for line segment and line protection, ATSE should not be short circuit and overcurrent protection function. CB ATSE is composed of two circuit breaker, and the circuit breaker is to break arc as their responsibility, asked his machinery should be fast tripping, thus the circuit breaker body slide fastener, buckle again; and PC ATSE does not exist the problem, PC product reliability is much higher than that of CB product.
2 breaking short-circuit current capacity of different. CB ATSE circuit breaker load short-circuit withstand current, the contact pressure is small, in case of a short circuit or current situation, when the contacts are excluded from limiting function, breaker tripping, thus breaking short-circuit current, causing the power side although there is electricity, while the load situation of power, can not meet the one or two level of load on the power supply requirements; and PC ATSE under 20Ie and above overload current, the contact pressure is not easy to be excluded, thus the contact is not easy to be welded, can ensure the reliable power supply load.
3 different security. Power in the conversion process in power superposition problem, PC ATSE fully consider this factor, PC and ATSE clearances, creepage distance is the standard requirements of 180%, 150%, and PC ATSE security is better.
4 contact material selection in different angles. The circuit breaker contacts generally choose silver tungsten, tungsten carbide and other materials, but this kind of material is easily oxidized, the spare contact long-term exposure outside, the surface easy to form conductive, difficult to remove oxide block, when the spare contact once put into use, contact temperature rise caused by burning or explosion increased switch; while the PC level ATSE considering contact oxidation of the material consequences.
Three, dual power automatic transfer switch ( ATSE ) development trend
ATSE generally consists of two parts: electrical switch body; controller.
The development trend of ATSE mainly includes two aspects: one is the switch main body, have very high impact current resistance ability, and frequent conversion; reliable mechanical interlocking, to ensure that in any state power can not run in parallel; not allowed fuse or tripping device, to prevent double the power switch with overload the output end the power-off phenomenon; four stage switch with N gathers after the function, in order to prevent ATSE in switching, different systems of the N line voltage drift, the current trend is inconsistent or shunt, resulting in residual current protection device malfunction. The controller using a microprocessor and an integrated chip, intelligent products, detection module has high detection precision, logical judgment module has a wide range of parameters ( voltage, frequency, delay time of the shield ) and the necessary condition of the display device, to meet the different requirements of the load; have a good electromagnetic compatibility, can bear the main the circuit voltage fluctuation, wave voltage, harmonic interference, electromagnetic disturbance; conversion time soon, and adjustable delay; can provide users with a variety of signal and control interface, communication interface.
From the ATSE development process and development trend, PC ATSE in practical engineering application will become the mainstream ATSE.