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From The Current Situation Of The Circuit Breaker To See The Development Trend Of China's Low-voltage Electrical Appliances
Jan 14, 2017
Low-voltage electrical future in technology and features will have great development, various relays, contactors and circuit breakers are widely used in the electronics and intelligent control. With computer technology, microelectronics, computer networks and digital communication technologies the rapid development of technology and artificial intelligence applications in low-voltage electrical appliances, smart appliances will be controlled by computer from simple single closure means replace the traditional function of the relays, the development of a complete theoretical system and multi-disciplinary intelligent electrical systems, became the field of electrical engineering in electrical switching equipment, power system protection, industrial supply and distribution systems and industrial control network technology new direction. Situation 1 low-voltage circuit breaker in transmission and distribution networks, molded case circuit breaker is an important basic one member, who often occurs electrical equipment overload, short-circuit those occasions, can safely and reliably cut off the fault current to prevent the accident and endanger the entire transmission and distribution system overseas ABB, Siemens, Schneider and other companies have introduced a new generation products, some domestic famous electric companies are also forming a low-voltage electrical field of the fourth generation of MCCB main technical features of the new generation of appliances: a high-performance contact interrupter system, modular structure, the electronic trip unit , superior performance, easy installation and diverse, and fieldbus communications. 1.1 high-performance contact interrupter system is currently ABB, Schneider, GE, and most other European companies a new generation of products using the double-break rotary contact system strengthen the short arc of nearly cathode effect, has a high arc voltage to increase the breaking capacity, and eliminating the need for flexible connection. domestic enterprises to apply for the double-break rotary contact relevant patents, such as Zhejiang Chint Electric Co., Ltd. invention patent application discloses a multi-pole double-break low-voltage molded case circuit breakers of the invention uses a relatively simple structure, to achieve between unipolar unit reliable mechanical connection and transmission; the same time, and more flexible installation convenient and simplified assembly process, reducing manufacturing costs 1.2 electronic trip unit electronic trip unit is a combination of microelectronics, computer and communications technology, with conventional thermal magnetic trip unparalleled advantages such as: trip stable characteristics, affected by the ambient temperature and climate; high accuracy tripping current and time; the current setting is adjustable and may set a different characteristic to adapt to the load protection requirements; electronic trip unit can be derived communications function, network control, it can also be derived region interlock, power monitoring and energy analysis and other auxiliary functions. each company can install a new generation of electronic MCCB trip, and gradually to 160A and below the small rated capacity current frame development. ABB has introduced SACEIsomaxS Molded case Circuit breakers microprocessor electronic trip, breaking mode and the special shape of the breaking element can disconnect the circuit breaker short-circuit current up to 200kA in a very short period of time 1.3 fieldbus communication global power and control specialist Schneider in M-series based on the introduction of the MT, MVV, MTE series framework of circuit breakers. shrink product form, complete protection function, intelligent controller in the original protection based on increased voltage , frequency and power measurements of harmonic and fundamental calculations, accurate analysis of power quality, with a variety of bus connections .Osmart Powerpact MCCB comply with UL, CSA and other certification, with double rotary cutting system, limit flow ability, breaking capacity of up to 100kA, with short circuit protection and overload protection, use and export of equipment OEM customers to provide a more effective support. 1.4 modular structure currently, Tianshui GS- 3 series intelligent controller is the core of intelligent ACB is equipped with a control element can be a display device or the grid current, operating voltage (with voltage display type), and achieve a variety of protection according to the size of the load current, so that the power lines and equipment against overload , crimes against short circuit, grounding fault according to the agreed-off protection control circuit control high precision, reliability, and load monitoring, fault alarm, fault diagnosis and online testing, on-site programming, cryptographic devices and other auxiliary functions. Siemens the company introduced its new generation of products SENTRONWL / VL circuit breaker series, SENTRONWL conventional circuit breaker rated current of 630 ~ 6300A, SENTRONVL molded case circuit breaker rated current of 160 ~ 1600A, two products, though we are not the same function, access route network is not exactly the same, but using the same communication protocol and device descriptions, with ProfiBCS DP, Ether net, RS 232C and other bus interfaces; WL through COM15 module allows network access ProfiBUS 2 two characteristics of low-voltage electrical appliances. with the trends and the emergence of new technologies, including modern design technology, microelectronics, computer technology, computer network technology, communication technology, intelligent technology, reliability technology, testing technology and other new technology, such as the future of low-voltage electrical technically and the function will have great development, various relays, contactors and circuit breakers are widely used in the electronics and intelligent control. with the rapid development of computer technology, microelectronics, computer networks and digital communications technology, and artificial intelligence technology in low-voltage electrical applications, smart appliances will replace the traditional relay functions from simple single closure device using computer control, has developed into a complete theoretical system and interdisciplinary intelligent electrical systems, electrical engineering in the field of electric power become switchgear, power system protection, the new direction of development of industrial supply and distribution systems and industrial control network technology. 2.1 high performance, high reliability, compact new low-voltage electrical appliances, high-performance addition to improving its technical performance, the focus of the pursuit of integrated technology economic indicators, such as low-voltage circuit breaker, molded case circuit breaker short-circuit breaking capacity, special attention arcing distance decreases, while miniaturization is demanded. this exchange exposure on the development of a new generation of compact low-voltage equipment is very important. in addition to raising is no longer one-sided pursuit of improving electrical and mechanical life, but to focus on product research and combination of features derived, breaking reliability (including reduced arcing distance to prevent arcing and white), operating reliability, silver contact reliability and Festival , energy and other aspects. 2.2 intelligent appliances, electronic appliances are intelligent smart appliances such tangible goods established on the basis of relevant knowledge and application of technology systems integration. with the simultaneous development of electronic technology and computer technology, smart appliances gone through several stages of the semiconductor, electronic, smart, etc. At present, with the ASIC and high-performance of the microprocessor (such as DSP), intelligent circuit breakers, intelligent control and protection, smart contacts and other functions to improve smart electrical components and intelligent network system will emerge with future releases of intelligence can be achieved only in the long delay, short delay, instantaneous overcurrent, earth, under the protection of protection, can be displayed voltage, current, frequency, active power, reactive power, power factor and other system operating parameters. and have a stronger analytical and comprehensive ability. in addition, due to extensive use of soft starters in the power supply system, inverter, power electronic transfer speed devices, uninterruptible power supplies and other devices to make the grid and distribution systems of a large number of high-order harmonics appear, and analog electronic trip unit generally reflect peak fault current, causing the circuit breaker under the influence of high-order wave malfunction. microprocessor intelligent breaker reflect the true RMS load current, so it can avoid the influence of higher harmonics. 2.3 intelligent network appliances in recent years, the emergence of fieldbus for industrial automation revolutionized sex change. fieldbus is a low cost, reliability and communication systems for use in industrial environments. requires only a two-wire cable, the wiring is very simple, reducing installation and maintenance costs. the smart appliances --- central control equipment, intelligent appliances and smart appliances, connected by a bus, in the low-voltage distribution systems and motor control centers on the formation of a unified intelligent monitoring, protection and information network system this system has the following advantages: when the system when electrical equipment failure, communication appliances and fieldbus capable of displaying a fault signal for easy troubleshooting, ensure the normal operation; semaphore system transmission is increased to improve the degree of system automation; accuracy of signal transmission increase, to ensure the system is running reliability. Therefore, this system allows the operator in the control room can easily control various field devices, and to keep abreast of the field equipment operation, handling a variety of failures. 2.4 extensions with the development of smart appliances, by smart electrical extension can perform other functions. Because of intelligent release low voltage circuit breaker microprocessor-based and has a communication function, so let the new generation of intelligent circuit breaker both power quality monitoring is a cost-effective approach and it is awarded at each end of the low-voltage power supply network and thus communicate with the central control computer available with grid power quality information for each endpoint. has a powerful detection and communication functions microprocessor-based smart appliances, which utilize intelligent Electric power quality monitoring is to achieve the most appropriate solution, which is a new development direction of the current medium and low voltage electrical appliances intelligent smart appliances to achieve PQ monitoring, there are two structures: one for low voltage intelligent power distribution system in the private intelligent power quality monitor; the second is to make intelligent low-voltage circuit breakers or protection relays both power quality monitoring 3 Conclusion future intelligent low-voltage electrical appliances will function more perfect, more excellent performance, higher reliability. Electric power supply system and the intelligent network will enable industrial automation systems management more perfect, greatly improve the security of the power supply system reliability and electrical equipment. application of artificial intelligence will improve electrical efficiency in the design, production and use, and reliability.