Explore the direction of protecting the transformer power parity method

Power transformer protection is an important direction of backup protection of transformers. As adjacent components and the internal fault transformer backup protection plays an important role in preventing the expansion of the scope of the failure to ensure the safe operation of the system. Primary and secondary wiring secondary wiring, voltage transformer secondary wiring and protective devices has its  electric meter  relationship correctness, and current transformer, which in actual operation, it is easy due to the wiring polarity errors The misoperation or refuse to move. This paper attempts to explore the direction of power protection, summed up in a simple and reliable method of calibration. The results show that by  air circuit breaker the actual failure of the power system, combined with CT, PT wiring polarity analysis can simply and reliably protect the correctness of power direction direction can be tested, given the equipment acceptance and routine inspection work, which greatly simplifies the work amount.

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 differential protection trip inspection process

Transformer differential protection trip, it should be checked and processed as follows: (1) Check the transformer body without exception, porcelain differential within the scope of protection checks whether flashover, damage, if there is a short circuit 2 lead if the transformer differential protection. no significant fault within the device, you should check whether the secondary circuit protection and fault, if there are two DC circuit ground. 3 or more after inspection  electric meter , should be sent immediately after the removal of a load test, and then try to send the trip may not be sending. 4 If the relay or secondary circuit due to failure or  Electric transformer  caused by moving the DC grounding points, differential protection should be out of operation, the transformer power transmission, and then deal with the secondary circuit and DC ground fault.

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.

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.

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.

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.

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.

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.

Explosion-proof motors are generally used in explosive environments

Explosion-proof motor is mainly used in coal, oil and gas, petrochemical and chemical industries. In addition, textile, metallurgy, city gas, transportation, grain and oil processing, paper making, medicine and other departments have also been widely used. With the development of production, there is a risk of explosion is also increasing, so how to choose a suitable explosion-proof motor it? We introduce the following aspects. Explosion-proof Motor and General Motors difference:  Electric energy meter  motors generally used in explosive situations; explosion-proof electrical junction box sealing better than ordinary motor; explosion-proof motor protection class minimum as I, but also some rather ordinary motor, it  electric meter  containing flammable, explosive, corrosive gases and relatively clean place, and used to drive a variety of machinery and equipment without special requirements, such as machine tools, pumps, fans, compressors,  circuit breakers , etc., and therefore can tell from the appearance. Through the motor can be divided into categories according to their functions and controls the motor drive motor; divided into categories according to AC power and DC motors; motor speed and power from the power relationship between the frequency classification can be divided into synchronous motor and induction motor;

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.

Properly evaluate the transformer insulation state of life of the transformer track

Transformer fault diagnosis technology is properly assess the state of the transformer insulation premise, while the transformer accurate grasp of the internal thermal state largely determines the load capacity and service life of the transformer, the transformer insulation fault diagnosis technology is an extension and expansion. Only correctly assess insulated transformer, the transformer life tracking to the actual state of the transformer to make the right  mcb circuit breaker . Papers from the power transformer fault diagnosis and internal thermal state prediction starting transformer condition for achieving these two important aspects of maintenance conducted in-depth research, the main research work: For the common method of BP neural network fault diagnosis of  Voltage stabilizer  insulation methods, the paper focusing on its network of selected learning sample creation, input selection, the convergence of the learning process and algorithm  electric meter  on issues such as research, was established based on the amount of items and bring variable learning rate improved BP neural network power transformer fault diagnosis method , analysis and simulation results show that the improved BP neural network can achieve better oil dissolved gas content data to the fault type mappings.

Specific methods are logical expressions and experiences simplification Simplification Act

In the design of the relay - contactor control circuit frequently encountered when multiple occurrences of the same label contacts phenomenon, and cost savings in order to simplify the circuit design must be simplified for contacts. In the relay - contactor control circuit contacts simplification, the specific methods are logical expressions simplification and experience Simplification, the former requires the designer has a good mathematical derivation ability, when the control circuit is  electric meter , due to the logical power transformers too cumbersome and error-prone process of mathematical deduction, is not practical; latter mainly depends on the designer's electrical controls design experience, the results are often not the most  mcb circuit breaker  simple circuits. Therefore, to find a theory is relatively simple, uncomplicated application simplification tool for relay - contactor control circuit design is important. The commonly used in electronic circuit simplification Karnaugh map used in the relay - contactor control circuit contacts simplification to study the Karnaugh map in the relay - contactor control circuit contacts simplification of the application.

With electrical protection and interlock device, is to enhance the machine's power systems and braking systems

Hoist control system for hoist high pressure, low driving force braking, the braking force is not driven, the driving force for the drag brake, brake band frequency, etc., and with electrical protection and interlock device, is to enhance the machine power system and the braking system, but also enhance the machine fails to protect the system. Two ore three levels of intake air shaft depth of 765m,  air circuit breaker  tons tub single bicycle cage, calculated to enhance the equipment selection, the final argument  mcb circuit breaker  in charge of the wellbore to mention extract task, the hoist maximum static tension: 200KN, maximum static tension difference: 180KN, motor power 2 × 800KW, the maximum rope speed 7m / s, using the electronic control system, the electronic control system is now in two ore three  electric meter  running into the wind failures are analyzed and explained approach. Electronic control equipment Scope: altitude does not exceed 1200m; ambient temperature not higher than 40 ℃, not lower than -20 ℃; relative temperature does not exceed 85%; around without conductive dust and metal and insulation has damaging effects of the gas;

Switching power supply due to its state at high frequency inverter circuit

Large inductance and high charging rectifiers, bulky, cumbersome. And this power is the energy storage capacitor operating mode "is done and that charge" mode, thyratron and a high  electric meter  storage capacitor a  Electric transformer  the state, seriously affecting the thyratron and storage capacitor life. The switching power supply due to their work at high frequency inverter circuit, the transformer core is very small,  Circuit breaker  the need for large-scale energy storage capacitor coupled inductors and charge, therefore, small size, light weight. Switching power supply for the energy storage capacitor to adopt a "charging is completed, the release" mode, thyristors and capacitors to withstand high pressure of the time far below the resonant charging mode.

Better protection switching power supply provides a very good condition

Switching power supply has several decades of development history, since the late 1970s, with the development of modern power electronics technology, there has been a lot of excellent  air circuit breaker  and high power devices and integrated, powerful companion chip, which is developed a high efficiency , small size, light weight, easy to control, and better protection switching power supply provides a very good  electric meter . Early general use of the excimer laser resonant charging power for tens of thousands of volts to charge the energy storage capacitor, and  power transformers the thyratron gas discharge excitation and thus the light. Such power generally frequency transformers, large storage capacitor.

Ranging data is low, affecting the data to improve the accuracy

Current international satellite laser ranging stations ranging widely used frequency below 10Hz, using pulsed xenon lamp-pumped laser devices, although this ranging technology is quite mature, but the disadvantage is obvious: repetition frequency is low,  mcb circuit breaker  capture the satellite, LEO satellites for some or even undetectable data; ranging data is low, affecting the data to improve the accuracy;  electric transformer  of the laser output beam and pulse wave instability brings the system unstable and affect  electric meter  accuracy. These are restricting the Satellite Laser Ranging further scientific applications. Especially in recent years, there have been some mm-level precision scientific applications, this laser ranging system accuracy and the number of observations have raised further requirements.

Low power high harmonic pollution is rising

Electrical construction electrical design basis is the most important documents, the main factors affecting the quality of the project are: the design file is executed in strict accordance with state regulations, the depth of the design and construction documents relevant professional close coordination between the degree. Therefore, the electrical design of the whole project a top priority. Decline in quality design is particularly serious in recent years. There may be multiple reasons, such as the design of the vicious competition, lower prices between companies,  Electric transformer units to reduce inputs in order to reduce costs and so on. However, these symptoms are not chronic, as long as the design unit attached importance recurrent organizational design personnel to learn the relevant design standards and  electric meter  the design process of supervision,  mcb circuit breaker  review, you can basically solve such problems, but such small changes it can make project supervision and construction will benefit. Affect the quality of several electrical engineering design problems violate or deviate from the design Electrical design specification With the popularity of various household appliances, low-voltage power high harmonic pollution is increasing, times and odd harmonic multiples constitute neutral current, neutral overcurrent and thus lead to the phenomenon of electrical fires is also increasing.