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.