The purpose of testing the impact of closing the transformer into operation before

The purpose of the impact of closing the transformer has two tests:
When opened load transformer, it is possible to produce over-voltage operation. When ungrounded or Petersen coil grounded neutral point in the power system, over-voltage amplitude up to 4 to 4.5 times the phase voltage; directly grounded neutral point, up to 3 times the phase voltage. In order to check the dielectric strength of the transformer can withstand full operating voltage or over-voltage, impact testing to be done.  electric meter  into no-load transformer inrush current is generated, the value of up to 6-8 times the rated current. The inrush current begins to decay rapidly, generally over 0.5 seconds is reduced to 0.25 to 1 to 0.5 times the rated current value, all in a longer decay time, up to large-capacity transformers tens. Due to a large  Voltage stabilizer  generated electric power, in order to assess the mechanical strength of the transformer, while the initial assessment of the inrush current decay protection devices can cause malfunction, need to do the impact test.

Transformer backup protection operation causes and treatment

Transformer backup protection reasons are: the high-pressure side of the transformer short circuit. Transformer low-voltage busbar short circuit. Since the failure occurred within the differential protection, differential protection failure. Low line failure,  Voltage stabilizer  tripping, causing a transformer overload tripping. If the over-current protection, found that the voltage drop, shock, arc, sound and so on, to deal with external transformer checks; If timely troubleshooting, you can try to send one, or should be ready to take safety measures to repair; If no problems are found, also may try to send a; transformer differential  air circuit breaker  non-, in addition to external examination, it should also be measured to check the insulation. If the low-pressure outlet failure, line protection tripping, you can manually destroyed fault line switch, power transmission and transformer. If the differential due to a fault occurs within the scope of protection, differential protection failure, the differential protection should be handled.

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.

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.

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.

Substation secondary cable has extremely important problem of electromagnetic compatibility

With increasing voltage levels and secondary equipment more and more decentralized, substation secondary circuit already in a strong electromagnetic environment in recent years has multiple causes substation DC system disruption caused by the secondary  electri cenergy meter  no fault tripping accidents, which caused a serious threat to the grid, affecting the safe and reliable operation of power systems. Therefore, the study of secondary cable substation electromagnetic compatibility  Voltage stabilizer  a very important theoretical significance and practical value. This paper focuses on the finite difference time domain method based on  air circuit breaker  transmission line theory and electromagnetic interference on the secondary substation cable coupling situation.

Buried cables and coaxial with frequency-dependent parameters such as multi-conductor transmission line transient electromagnetic process FDTD calculation method

Get transfer impedance and transfer admittance amplitude-frequency characteristics, and the phase-frequency characteristics can be obtained, and the test system is relatively simple; applies not only to single-core shielded cable can also be used for multi-core shielded cable transfer impedance and transfer admittance measurement . With other methods of  electric meter  results were compared with measurements to verify the correctness of this measurement method. Proposed for research overhead lines, underground cables and coaxial cables with frequency-dependent  air circuit breaker  as multi-conductor transmission line transient electromagnetic process FDTD calculation. The main research results to establish a substation switching transients field time-domain simulation model, based on the spark  Voltage stabilizer , the isolation arc discharge channel switching operation, time-varying resistance and inductance formulas. A typical substation switching transients by fitting the measured field data obtained arc discharge channel switching time-varying resistance range. Based on this model to study the impact of switching transients field intensity and rise time of a variety of parameters for EHV and UHV substation switching transients field study provides a theoretical basis.

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.

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.

Fault Tree Analysis (FTA) to build a power transformer internal fault

Power transformer fault location method of providing practical basis. Analysis of power transformer fault detection technology, to further explore the power transformer internal fault detection and effective way. The use of fault tree analysis techniques (FTA) to build a power transformer internal fault classification  air circuit breaker , will be  electric meter  electric power transformer fault localization studies. Study the characteristics of ant colony algorithm, principles, algorithms and  Voltage stabilizer  model. Pheromone ant colony algorithm, the information heuristic function factor, the number of ants, ant colony algorithm expectations inspired performance factors on the impact of simulation studies.

Explosive coal dust and other main method is to detect explosives content

With the social and economic development, people are increasingly concerned about safety issues. Coal mine fire and explosion is an important aspect of safety management. Current efforts to prevent gas and coal dust explosion is the main method of detecting  Voltage stabilizer , but not much consideration to eliminate the explosion. Since the explosion and combustion essentially the same, are redox reactions, chain  Circuit breaker  fire and explosion on the same principle. In this paper, coal and other industries fire and  electri cenergy meter , cold aerosol fire and explosion, and its performance, the role of the theoretical analysis. Agents should have a fire and explosion and fire main properties are different.

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.

As long as contact with their tiny spark can cause a fire and explosion

Fire and explosion are flammable gasoline and diesel. Especially gasoline, as long as the contact with its tiny spark can cause fire and explosion. Therefore, the majority of  electri cenergy meter  farm machinery service organizations and driving operators to strictly comply with fire safety regulations. In the depot nearby, smoking. All ignition items, such as Voltage stabilizer , matches, detonators, explosives, oxygen bottles, cotton and other items are not allowed into the depot. electric meter  or refueling, use explosion-proof lighting, you can not use an open flame and oil lamps. Around the depot to be labeled "No smoking, no smoking" and other eye-catching slogans.

Low-cost explosion of new materials is undoubtedly a piece of meaningful work

Explosion-proof sheet metal fabrication difficult, requires high precision manufacturing nip machinery and material attached to ensure no oxidation, organizational  electri cenergy meter  uniform heat treatment apparatus and other processing equipment, making the cost of greatly improved, a proof sheet metal processing costs to attributable costs more than 90 bowel. Therefore, seeking reliable, low cost explosion-proof sheet material is  power transformers  a new meaningful work. Voltage stabilizer  artificial graphite is an excellent corrosion resistance, and ease of processing of brittle materials. Used to manufacture explosion-proof film, when it burst, it is possible to achieve similar shear rupture disk bursting form, to get the maximum through the area.

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.

Homemade hydrogen station in two ways, one is the use of chemicals hydrogen, the second is the use of water electrolysis hydrogen

Currently the majority of our high-altitude stations compressed hydrogen from the hydrogen production plant, part of the high-altitude station using a homemade hydrogen.  Electric energy meter  station in two ways, one is the use of chemicals hydrogen, the second is the use of water  electric meter  hydrogen production. I got another one hydrogen from water electrolysis hydrogen station, so the hydrogen transport, storage and use of hydrogen process must pay attention to fire and explosion.  Voltage stabilizer  is a flammable and explosive nature of hydrogen gas, hydrogen flame burning in air temperature up to 1500 ℃, the oxygen in the combustion flame temperature up to 2000 ℃ ~ 3000 ℃. Its penetration force, highly penetrating, high temperature, high pressure, it can penetrate very thick plate.

Induction meter only in a very narrow frequency near the frequency range and the voltage

Induction meter only in a very narrow frequency near the frequency range and the voltage and current for the fundamental conditions to ensure the best [for performance. In the case of a distortion of the waveform, the harmonic voltage and current  Voltage stabilizer  the turntable through  Circuit breaker  magnetic flux, causing fundamental changes in the magnetic flux distribution, thereby affecting the G-wave generator driving torque; Also, because the braking torque and flux distribution is almost irrelevant,  Electric energy meter  rotational speed changes, power metering errors. The harmonics of the power meter measurement error of j depends on how much content Mu are waves, harmonic current direction and other factors.