When charging the transformer should put all protection, and to ensure there is sufficient sensitivity

When charging the transformer should put all protection , and to ensure there is sufficient sensitivity , taking into account the impact of inrush current protection system . To ensure the stability of the system , if necessary, reduce the charge should be preceded by the relevant line of active power. Large current grounding system before charging or transformer outage must be neutral grounding blade closed. After charging , check the supply voltage, so that each side of the voltage transformer does not exceed 5% of the corresponding tap voltage . When the transformer into operation , should be less affected side of the inrush current power transmission . Generally start charging power supply side , after closing the load side switch. When a power outage , you should pull the load side of the switch, pull the power supply side of the switch. If 220kV transformers high and low pressure  mcb circuit breaker , when power by charging high side and low pressure side of the tie should be on the low side splitting power outage . When the ring transformer operating system , you should select the correct charging terminal to reduce the voltage difference tied at . When the transformer parallel operation , shall comply with the conditions of parallel operation . Transformers stop, when an impact  power transformers  as when the power would run the system transformer neutral grounding , protection must be adjusted according to the requirements of operating procedures in the adjustment process, should be fit after pulling principles. For stop after power operation in hot standby transformer neutral point grounding blade should close the state.

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.

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.

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.

Secondary equipment electromagnetic compatibility problems have become increasingly prominent

With the ultra-high voltage grid, intensive direction and microelectronics technology in the wide application of the secondary equipment, substation electromagnetic Voltage stabilizer , secondary equipment, electromagnetic compatibility problems have become increasingly prominent, research substation switching transients and the effect on two times the cable coupling mechanism having a weightTo  mcb circuit breaker  and application value. This paper, based on finite-difference time-domain (FDTD) method to study the field of substation switching transients time-domain  air circuit breaker , substations and cable trench soil transient electromagnetic field distribution, bounded wave electromagnetic pulse (EMP) simulator transmission line designed for near-field Finite length cable coupling mechanism, as well as the transient electromagnetic field coupling cable numerical methods.

Transfer admittance and unit-length parameters broadband measurement method and short-circuit fault substation

Research substation transient electromagnetic environment electromagnetic coupling problems secondary cable has an extremely important theoretical significance and practical value. In this paper, the National Outstanding Youth Science Fund Project "EMI coupling mechanism," focuses on the transfer impedance of shielded cable,  mcb circuit breaker  and unit-length parameters broadband measurement methods and substation system short circuit fault, lightning and switching operation on the secondary  Circuit breaker  electromagnetic coupling mechanism, through the measurement results and other literature comparing the calculated results to verify the measurement methods and calculation methods herein correctness. A new measurement shielded cable transfer impedance and transfer admittance easy way.

Multi-rate meter using microcomputer control, you can set up multiple sessions

To rationalize the allocation of electricity, power supply bureau has been implemented on the user's electricity sharing billing system. Electricity users in different periods, the electricity price is also different. The factories and enterprises in order to save energy and  Voltage stabilizer  expenses, but also for departments, workshops and other subordinate departments to implement a time-sharing administration. There are a variety of multi-rate watt-hour meter market sale. Multi-rate  mcb circuit breaker  microcomputer control, you can set up multiple sessions, price, electricity maximum demand can also be set to allow the maximum load, to achieve load control. Existing multi-rate watt-hour meter in common is that each meter at a pre-set period of time to accumulate on the battery and charging.  electric meter  on the meter input and output display device for input and output display settings. Press the button to switch the meter reading personnel electricity or electricity display can also be switched each time readings. The table has a small capacity memory for storing values ​​and the accumulated value of each set of data. This meter is a with data acquisition, data processing and full input and output SCM application system.

Multi-rate meter and time switch constitutes Indexer

Limited period of time each day measuring energy to electrical energy at different rates denominated tables, also known as the timeshare interest rate level meter or meter . Multi-rate watt-hour meter has a number of degrees , respectively, in each of degrees within the prescribed period of time to work out the different measurement periods  Circuit breaker energy tariffs . Using multi-rate watt-hour meter peaks and valleys of electricity can be measured separately , namely billing, is an economical means to regulate the electricity load with effective measures . Multi-rate watt-hour meter energy meter by the agency ,  electric meter  protractor and time switches. The active power integrated over time to measure the AC circuit functional capacity of the meter , also known kWh meter or meter . Power meter is widely used, can be used to measure the energy emitted power plants and a variety of user consumption of electricity , and as  mcb circuit breaker  and collection of electricity basis. Meter is divided into single -phase energy meter and three-phase energy meter , there are some special-purpose power meter, such as multi-rate meter , largest scale , reactive power meter, DC energy meter , standard meter and so on. Induction single-phase energy meter system structure shown in Fig. Voltage element 1 and the current element 2 from the corresponding coil and core components.

Online adaptive protection can automatically identify and diagnose the fault type

Change caused by the regulator tap the TA secondary current mismatch, seriously affecting the accuracy and reliability of the differential protection. Online adaptive protection can automatically identify and diagnose the fault type and automatically  mcb circuit breaker  and characteristics of protective action. As adaptive protection hardware foundation, the rapid development of computer systems makes adaptation more extensive  power transformers  prospect theory. In-depth understanding of transformer differential protection based on an adaptive principle and criteria currently used inrush current is proposed by combining the new voltage switching principle and the second harmonic restraint combination of complex criteria.

Do not use iron tools percussion drums, especially installed over empty bucket of gasoline is more dangerous

Around the barrels of gasoline or diesel, especially for warehouse storage of barrels of oil to be ventilated to ensure timely  mcb circuit breaker of fuel vapor. In the depot or reservoir area over the ban erection wires. Do not use iron tools percussion drums,  Voltage stabilizer  installed over empty bucket of gasoline is more dangerous. Because the barrel of the combustible gas tap out a case of Mars, it will explode and burn rapidly.  power transformers  collision between drums, do not wear shoes with nails to work in the depot in order to avoid touching the iron sparks cause fire. Stained with oil cloth, cotton yarn and gloves and other items, do not pile up in the depot in order to avoid temperature rise caused by spontaneous combustion.

A sudden increase in pressure automatically when the pressure relief safety devices rupture

Explosion-proof film, also known as proof membrane, blasting plate, since rupture disk. A sudden increase in pressure automatically when the rupture pressure relief safety device. Installed in the presence of flammable gases, vapors or dust and other  mcb circuit breaker  pressure vessel or piping, equipment or pipeline materials when suddenly boost or exceed the design pressure transient response can be  power transformers  blasting pressure relief. Which is characterized by multi-release materials,  Voltage stabilizer , simple structure, the device can withstand rupture test conditions. For high viscosity and corrosive materials equipment systems and easy to crystallize or polymeric materials can clog valves and does not allow any fluid leakage occasions.

Tire Explosion agent is a top-secret American Aerospace 60s Supplies

Tire Explosion agent, recently passed the China National Quality Supervision and Inspection Center of rubber tires put an end to slow leak and instantly blocking the drain hole firmly tie performance testing and approval by the State Bureau of Technical Supervision, while achieving the security provided by the Northern Jiaotong University and the proof  mcb circuit breaker  Insurance Co., Ltd. provides quality  air circuit breaker , successfully received the automotive safety products into the Chinese market permits. Tire Explosion agent is a top-secret U.S.  Voltage stabilizer  1960s, the Gulf War into the military, has been converted to civilian use to decrypt, after years of extensive use, it can effectively protect automobile safety, to the maximum extent relieve traffic explosion due to leakage tie tires, caused by the loss and annoyance. Tire Explosion agent injection tires can eliminate slow leak, perforation can prompt asking for blocking prison, especially for automobile tires at high speed due to warming caused by the burst, better preventive effect. Also has a bullet-proof function. In addition, can extend tire life, save fuel.

Ammonium nitrate was modified so that it has retained the explosive fertilizer and lost

Ammonium nitrate is widely used in agricultural fertilizers, industrial explosives production. Because of ammonium nitrate with rice bran, diesel after simple mixing explosives can be obtained, so criminals often use private agricultural  electri cenergy meter  nitrate explosives made ​​and used for terrorist activities, has attracted the world's attention. However, as an efficient fertilizer ammonium nitrate is still a vast market, so how ammonium nitrate was modified so  mcb circuit breaker  the explosive fertilizer and lost, becoming a national scientists placed in front of the subject. Ammonium nitrate explosive two main reasons: their thermal decomposition in a short time, a sharp release of large amounts of gas and cause an explosion;

Ex-wave plate for hanging protective properties of the shutter is more mature

Civil air defense projects ventilation equipment types used internally complex, the production process is relatively backward means of detection, product quality can not effectively ensure ventilation. In order to regulate the ventilation ventilation protective equipment performance testing, protective equipment to improve product quality, it is necessary to develop a standard set of test bench. Currently, hanging plate proof protective  power transformers  of wave shutter has been more mature, and the ventilation valve on the hanging board performance study was relatively small. In this paper, the shutter mechanism and close the ventilation air flow  air circuit breaker , hanging plate ventilation valve test bench is designed to provide a theoretical basis. Hanging plate valve closed model mainly by the base plate,  mcb circuit breaker , hinged seat and limit housing component. Close valve when hanging panels, new air vents through the hanging plate inside and out diffusion chamber. If the wind gradually increased from 0 to slow the increases to a certain extent from the rear overhang board is placed phenomenon, this time from the air flow is called swing wind; when ventilation rate continues to increase to a certain extent, then hanging plate closes and the the air flow is called close air volume. Put the wind from the air flow volume and turn off the ventilation valves belong performance.