Short circuit and ground fault display device can be used to detect medium and high voltage power system short-circuit

Short circuit and ground fault display device can be used to detect medium and high voltage electric power system short-circuit or ground fault, the device has the strength of  electric meter  isolation, safety, ease of installation, low energy consumption and low cost. DC contactors developed on the basis of intelligent hybrid DC contactors. The first  mcb circuit breaker  of the contactor power electronic devices to complete the current transfer DC contactors and breaking when closed, to achieve DC contactor no arc operation. No arc making and breaking the DC contactor institutions significantly reduced electrical life and reliability significantly improved, with good prospects.

Traditional contactor product-oriented design methods, using trial and error methods

Traditional contactor product-oriented design methods, using trial and error, long development and production cycles, low efficiency, high cost; and product performance and other aspects of electrical life is often difficult to achieve the desired targets. The merits of the dynamic characteristics affecting the performance of high-power DC contactor and electrical life is good or bad, is an important factor in the mechanical  electric meter . Therefore, the use of virtual prototyping technology to the dynamic characteristics of high-power DC contactor for analysis and optimization has important theoretical and practical significance. In this paper, a series of high-power dual-winding DC contactor for the study, based on virtual  power transformers  technology combined with the structural characteristics of the type of contactor, analyze its static mechanical properties of the reaction force, the establishment of an equivalent circuit model double  air circuit breaker , the development of direct contacts analysis of dynamic characteristics of virtual prototyping system, and thus on the dynamic characteristics of contacts to optimize the design in order to improve its reliability and electrical life. In this paper, multi-software co-simulation method to establish the dynamic characteristics of high-power DC contactor analysis model.

As a controlled contactor control switch is widely used in electrical power transmission and industrial production

As a controlled contactor control switch is widely used in electrical power transmission and industrial production, which directly affect the performance and reliability of the entire power system performance and reliability. Electromagnetic contactor is closed and the key factors in the process of existence arc wear, especially in applications where high power DC arc of contact damage is more serious, the decision to become high-power DC contactor electrical life of breaking. DC  mcb circuit breaker  using conventional hybrid power electronic and mechanical switches connected in parallel method integrated the advantages of both, to achieve mixing without arcing contacts off, but due to the high power electronic  electri cenergy meter  cost, large size, the drive control circuit is complicated, making the process in high power applications do not have a high market value. In this paper, railway locomotive power DC contactor for the study presents a new high-power DC contactor hybrid design approach to contacts in the open, no arc affect the basic design requirements related to the course of action. The new proposed hybrid power DC contactor is closed by the bounce arc elimination circuit, breaking the circuit and eliminate the contact arcing composition itself.

When existing traditional DC contactors work, pull the breaking process should arcing

Existing traditional DC contactors work, pull the breaking process should produce an arc , and the contactor coil has to rely on the pull to keep energized contactor closed state , there is a coil power consumption, power run when noise, there is a strong arc shortcomings off when the main contact circuit , so not only caused a lot of energy waste , pollution of the surrounding environment, but also greatly reduces the electrical contactor life . This article is based on the original DC contactor on its  power transformers  and no arc transformation , which developed a non- permanent magnet DC arc contactor. It uses NdFeB rare earth permanent magnet  mcb circuit breaker  and high- power electronic devices , such as the combination of acting on the contactor electromagnetic system . The use of magnetic flux generated by the permanent magnet to pull the state to maintain the coil is energized only when breaking moment , the rest of the time there is no  Circuit breaker  the coil from the fundamental solution to the problem of power consumption . Through the use of special measures to release a good solution to power and voltage protection issues such as permanent magnetic contactor , contactor so it has a strong magnetic pull , permanent magnet to keep saving , noise-free function. Meanwhile , in the original contactor in parallel across a triac , contacts and thyristor action sequence by using a special control unit has the strength of electrical isolation of control .

Electro-pneumatic contacts with compressed air as a power

Due to the high electric and diesel locomotives main circuit voltage, current large, so is used to turn off the main circuit and open contacts must have a larger opening and contacts from the contact pressure to prevent contact temperature is too high , and ensure that there is sufficient contact arcing when disconnected and insulation capability . Electro-pneumatic contacts with compressed air as power, fully meet these requirements , which are widely used in electric and diesel  mcb circuit breaker . But electro-pneumatic contacts have their innate weaknesses : ( 1 ) it is one of the key components to soften or harden rubber cup extremely dramatic changes in temperature and deterioration and cooperation between the cylinders , causing electrical action failure , thus failure ; ( 2 ) it uses  Voltage stabilizer  air as power, complicated duct runs , to a certain extent, affected the reliability of electrical appliances ; ( 3 ) its use of the environment has  air circuit breaker  requirements. It is because of these electro-pneumatic contactors weakness in foreign countries, has been widely used locomotive circuit electromagnetic contactor. With the rapid development of rail transportation technology, machine owners electromagnetic contactor circuit to replace the electrical contacts has become one of the empty trends . Meanwhile the city subway, oil drilling , plating, wind power and other industries also require high power DC electromagnetic contactor. Therefore, the development of new magnetic contactor has become essential.

Due to constantly switch loading and unloading, excitation contactor frequent contacts with electrically controlled pull and release

Problems in the line locomotive traction process, regularly running load and unload meet changing requirements in order to achieve a constant speed running resistance. Due to  mcb circuit breaker  switch loading and unloading, excitation contactor frequent contacts with electrically controlled pull and release, excitation contactor off by the strong current  power transformers  moments often burning the main contacts. At the same time due to electrical control contacts open distance and overtravel can not achieve the same, 6 Taipower can not meet the synchronization control contactor closing and opening, individual electric contacts early release caused by the burning of contacts, it is necessary to take effective measures to prevent it.

Braking resistors are made locomotive excitation regulator control

Wheel on the train through the kinetic energy into electrical energy consumed in the braking resistor, then the form of heat escaping into the atmosphere. In this process, generated by the traction motor shaft counter moment acting on the motorcycle wheel braking force generated on. The braking effect is called resistance braking.  electric transformer  diesel locomotives, most equipped with resistor braking devices. All Dongfeng diesel locomotive braking resistor circuit conditions substantially the same as the braking resistor are made locomotive excitation regulator (or resistor braking control cabinet) control, when the resistor  power transformers , the excitation regulator (or resistance brake control cabinet) according to the engine speed signal and provides the braking current and the magnetizing current  Voltage stabilizer  and actual braking current and excitation current is compared with a reference value by calculation, outputs a signal to control the chopper excitation current excitation system, the braking current and excitation current limit within a predetermined range.

Specifically for switchgear temperature measuring instrument, little, live temperature monitoring, there are two main methods

Specifically for switchgear temperature measuring instrument, little, live temperature monitoring methods are mainly two: First, the measured surface coated with a temperature-dependent color light-emitting materials, by observing the color changes to roughly determine the temperature range, this method is low accuracy, poor reliability, quantitative measurement can not be performed; another method is  electric meter  an infrared  power transformers , infrared temperature measurement accuracy and reliability of the test by atmospheric background, the distance factor, the object emissivity the operating wavelength, regional and instantaneous FOV and other factors, it is very difficult to do accurately measure; and because this  Voltage stabilizer  equipment and there are no obstructions between the measured point can be accurately measured, so that the high pressure switch cabinets and other specific occasions too convenient. Therefore, the author developed a contactless temperature sensor line monitoring system, since the monitoring device at a high potential, surveyors can not close, so the temperature sensor system using front-end power.

For the capacitor voltage transformers for transient response characteristics have not made a clear standard

Characteristics of the capacitor voltage transformer is also an important research topic. Especially when the high voltage line short-circuit occurs, the capacitor voltage transformer circuit generates the transition process on the protection device has great  Voltage stabilizer , and a wide variety of protection devices, but also more complex, in order to ensure a variety of protection in all cases the correct operation is difficult. So far, the capacitor voltage transformers  mcb circuit breaker  characteristics have not made a clear standard, can simply make provision in certain aspects.  Circuit breaker , to ensure the voltage of the white component at 20 ms after the pre-fault voltage amplitude drops below 10%. Even so, the transition process on the impact of protective actions should also be considered, especially for fast action emerged in recent years a new type of protection.

Also increasingly electronic voltage transformer replacement in

In the power system , voltage transformer can play a role in protecting the power grid . With the sensor technology, intelligent technology and grid technology continues to evolve ,  Circuit breaker  advanced voltage transformers , voltage sensors began to digital signals, network transmission , and linear measurement direction of rapid development , in order to ensure the power grid to meet the increasingly developed requirements. In recent years, electronic voltage transformers , the abbreviation is EVT, in the power system has been widely studied , electronic  mcb circuit breaker  used in technology, including computer technology, optical technology and communication technology. In addition, with the continuous development of science and technology level , electronic voltage transformer also increasingly replacement , at present , there is a new type of high-voltage electronic voltage transformer has been around and has been used , this article  air circuit breaker  high-voltage electronic voltage transformer the sensing principle and structure . New high-voltage electronic voltage transformer of this new medium and high voltage electronic voltage transformer is based on the coupling capacitor EVT. Compared with conventional voltage transformer , this transformer has a high safety performance , relatively low cost , insulation performance, error is small , the control room environment is good and relatively simple to operate and so on. New high pressure EVT key structure, including: high-precision micro current transformer , coupling capacitors, and power amplifier .

Using fast saturable reactor type damping allows ferromagnetic resonance damping characteristics and transient response characteristics

In a foreign country more than fifty years of development history, made from 1964 CVT capacitor plant in power since the birth, also accumulated forty years of manufacturing and operational experience, has now matured. Especially in the last decade, CVT in accuracy and increase output capacity and the successful use of fast saturable  air circuit breaker  damping allows ferromagnetic resonance damping characteristics and transient response characteristics significantly improved, etc. has been a breakthrough. CVT has reached or exceeded electromagnetic voltage transformer (VT) of the performance  mcb circuit breaker , but also has a high dielectric strength, will not happen with the system  Voltage stabilizer  resonance, low prices and high voltage coupling capacitor for carrier doubles as a communication (PLC) and so on. Therefore, CVT in China's electric power system has been widely used.

Elimination and suppression of ferromagnetic resonance, has taken various measures

In order to eliminate and suppress the ferromagnetic resonance, to take a variety of measures, the selection of the excitation characteristics of a good TV; openings in TV delta winding open end of the installation of a linear damping resistors or bulbs; open delta windings connected in parallel in TV multifunction computer harmonic  mcb circuit breaker  ; the TV  Circuit breaker  to a neutral point of zero sequence TV; side of the TV once in series between the neutral point and ground resonance eliminator. Operating experience shows, TV wiring measures to curb ferromagnetic  electric transformer  a good effect, so it is widely used in domestic power companies. Together with the 10 kV bus through the TV Burning Accident Zero Sequence analysis of the causes of damage explores the TV and from the TV source parameter design proposed ultra-low frequency oscillation suppression over current solutions.

E-glass fiber and its products have a range of excellent performance because

The transformer is an important power industry for substation equipment, ensure that the transformer operation safety and reliability, not only for the promotion of economic development and social progress of great significance, but also to ensure that people's lives and property also has a very important significance. E-glass fiber and its products because with a series of excellent performance, especially good  power transformers , high heat resistance, has been in power electrical industry has been widely used. In recent years, due to the power transformer and technological progress and product upgrading, glass fiber and its products in the manufacture of dry-type transformers, has become an indispensable important material.  air circuit breaker  of the development since the Faraday discovered electromagnetic induction has been more than a century ago is the earliest of the transformer dry-type transformers. Because of this transformer can not be bigger, high voltage can not do technically was extremely restricted. The emergence of  electric transformer technology development made an indelible achievements. Currently, the transformer industry mainly to produce mainly oil-filled transformers, which accounts for about 60% of total capacity to 70%. In the use of oil-filled transformers have some fatal disadvantages, limiting its wide application.