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The split core current transformer is mainly used for electrical measurement and electrical maintenance. It has the characteristics of high flexibility, good linearity, reliable operation, and convenient installation, especially its open-close structure can be completed without tools. Without changing the cable, the device can be used more and more widely. We can choose the corresponding split core current transformer ratio according to the operation requirements of the system.   Split core current transformer   1. Select the corresponding specification product according to the parameters such as primary current and busbar section. A wire passes through the window of the transformer.   2. When the instrument position of this device is far away from the current transformer or the loop load is large, the specification of 1A secondary current should be given priority;   3. Pay attention to the number and specifications of the busbar, and then we can determine to choose an split core current transformer that matches the window size.   4. We can choose the ratio of the rated current ratio according to the size of the measured current. We should choose a rated current that is two-thirds larger than the measured current;   But there are things that need to be paid attention to, for example, when we open the flap, stop the secondary wiring through the crimping piece, and reset the flap after the secondary wiring is led out. Electric energy metering can be directly applied to the small hole of the flip cover to increase the seal and prevent electricity theft.   The working current of the split current transformer does not exceed 1.1 times the rated value for a long time, but it can be used for a short time at 1.2 times the rated value, but pay attention to the time, the time cannot be too long, and the time cannot exceed 1 hour;   Split current transformers are suitable for general measurement and maintenance of highly maneuverable, limited space or non-continuous power systems.   Hemei Electronics, with products covering more than 30 provinces, cities and districts in China and exported to more than 20 regions, mainly produces magnetic materials/current transformers/power supply CT/transformer cores/electromagnetic shielding shells/high-frequency current transformers and other business segments. The products are mainly used in power, communications, environmental protection, water affairs, automobiles, high-speed rail, military industry, new energy, rail transit, smart cities, smart fire protection, intelligent low-voltage test units, industrial Internet of Things, industrial control automation, power station area transformation and other industries.   Hemei Electronics is an innovative development-oriented enterprise with excellent equipment, advanced technology and a complete quality assurance system. It is also one of China's self-operated import and export enterprises.

According to the installation location, the split current transformer can be divided into indoor and outdoor. The indoor type is less than 20kV; the outdoor type is greater than 35kV and above.   According to the installation method, it can be divided into wall type, support type and load type. The wall-mounted type is installed in the hole of the wall or metal structure to save the wall bushing; the support type is installed on the plane or column; the load type is 35kV and above transformer bushing or multi-oil circuit breaker oil tank. It is called sleeve type.   Split current transformers can be divided into dry type, casting type, oil-immersed type, etc. according to insulation performance. Dry impregnated insulation glue is suitable for the opening and closing of low-voltage household current transformers; the casting type uses epoxy resin as the insulating material, which is mainly used for current transformers of 35kV and below; the oil-immersed type is mostly outdoor.   According to the coupling mode of high and low voltage components, the new split current transformer can be divided into electromagnetic wave coupling, capacitive coupling and photoelectric coupling. Among them, the optical current transformer has better performance. The new type of open-close current transformer is characterized by no direct electromagnetic connection between high and low voltage, which greatly simplifies the insulation structure; no need to consume a lot of energy during the measurement process; no saturation, wide measurement range, fast transient response, high accuracy; light weight and low cost.   In the same circuit, a large number of open-close current transformers are usually required. High-voltage current transformers are usually composed of multiple independent magnetic cores and secondary windings, without magnetic connection, and the primary winding is shared, forming multiple secondary windings with the same current ratio and current mutual inductance. Equipment For open-close current transformers of 110kV and above, the primary winding is usually divided into several groups, and the series and parallel connections of the windings are changed by switching to obtain a mutual inductance ratio of 2:3.

The split core current transformer is a commonly used current transformer in the equipment. They have good sensing effect and can improve the efficiency of the equipment. It has a good effect in controlling current and completing the conversion of upper and lower voltages. How can we restore it to make it work smoothly and avoid vibration? You can try the following steps:   1. Fix with positioning screws: The positioning screws are locked 90° between the two positioning screws. In the traditional fixing method, the front end of the screw contacts the shaft, which may damage the shaft or make it difficult to remove.   2. Fix with clamping screws: Use the tightening force of the hexagon socket bolt to narrow the gap and clamp the shaft of the split and closing current transformer. This method is convenient for installation and removal without damaging the shaft.   3. Keyway fixing: Suitable for large torque transmission. In order to avoid axial sliding, the fixing screw and the clamping screw are usually separated from each other.   4. D hole fixing: If the motor shaft is D-type, if it cannot be fixed, the fixing screw hole split current transformer can be processed into the D hole size corresponding to the motor shaft and fixed with a fixing screw without worrying about slipping.   5. Fixing of shrink sleeve: Tighten the four positioning screws on the end face to compress the sleeve, which is suitable for the connection and fixation of some high-torque stepper motors and servo motors.   The split type current transformer can switch between high and low voltages sensitively, allowing the device to switch back and forth at different voltages. The normal operation of the maintenance equipment is mainly restored through these methods.

When the split core current transformer is operating normally, everyone should stop the device according to the technical requirements such as the specification book. To be more clear, let's take a look at this.   1. The split-type current transformer is constructed according to the drawings, the wiring is correct, the wire number labels at both ends are clear, and the label range meets the requirements.   2. The current and voltage circuits should be grounded at the secondary side outlet of the transformer. The voltage circuit should be maintained with a fuse.   3. The secondary circuit of the panel cabinet should not have a connector, and there should be no connector in the middle of the control cable or line. If there is a connector, it should be connected through its long junction box.   4. The secondary circuit of the split-type current transformer should be well insulated from the ground, and the voltage circuit and the current circuit should not be mixed.   5. The wiring of the secondary circuit should be arranged evenly and beautifully, and the connecting screws of the wiring and electrical components and junction boxes should not be loose. The spacing between the wiring binding points should meet the requirements.   6. The cycle cannot be reversed, and the phase sequence and phase difference should meet the design and specification requirements. For the transformer wiring with differential maintenance, it is necessary to measure the phasor diagram of the two arms before putting it into operation to check the correctness of the wiring.   7. Copper wire should be used for the secondary circuit conductor or cable. The cross section of the voltage transformer loop shall not be less than 1.5mm. Special current terminals should be selected for the socket junction box. The unused secondary winding of the transformer should be short-circuited and grounded on the terminal board.   The above are the requirements that should be followed when installing the split-type current transformer. In order to ensure normal operation and prevent future problems, everyone needs to follow the correct installation steps when installing. While meeting their technical requirements, we hope to deepen everyone's understanding of the product.

At present, many automation equipment requires some induction equipment, such as split core current transformers. As long as the split current transformer is used, the induction work can be completed and the automation of the equipment can be completed. You can also change the voltage. So, what kind of equipment do we need to test the transformer?   1. Current booster: used in conjunction with the voltage regulator, it can generate various experimental currents required. Its capacity and cost increase with the increase of current.   2. Standard current transformer: used as a standard instrument for verifying transformers. Its accuracy is usually more than two levels higher than the accuracy of the device under test.   3. Transformer calibrator: can measure the error between the standard current transformer and the experimental switch current transformer, and display the working current.   4. Load box: can simulate the actual working state of the switch current transformer under experimental conditions.   5. Voltage regulator: used to adjust and test current, usually on the same control platform as the maintenance switch device, divided into coarse adjustment and fine adjustment voltage regulators to meet the needs of fine adjustment.   6. High current connection cable: used to connect hundreds or thousands of amperes of current.   The open-close current transformer has a strong inductive ability and can be used flexibly to switch between high and low voltages. During operation, it can prevent abnormal operation of the equipment due to excessively high or low voltage.   Hemei Electronics attaches great importance to technological innovation and product development, and has obtained a number of intellectual property rights. The company has strong technical strength, exquisite production technology, advanced inspection equipment and excellent equipment, including fully automatic transformer inspection bench, intelligent transformer calibrator, interference discrimination partial discharge tester, three-frequency generator, high current withstand voltage tester, balance characteristic tester, and high current load tester, which provide reliable guarantees for the quality of transformer production and are well received by users. The products are sold well in various places and exported to more than 20 regions including Europe, America, Africa, the Middle East and Southeast Asia.   On the way of exploration and discovery, leading the industry with innovation and setting a benchmark with quality has always been the purpose of Hemei's development. We are anxious about what customers are anxious about, think about what customers think about, and always put the interests of customers in mind. From understanding customer needs, to designing and producing products, to delivering products to customers in a timely manner, and to providing follow-up services, Hemei people always have only one thought in mind: service and customer satisfaction. Seeking truth and innovation is the unremitting pursuit of Hemei people.

The opening and closing of the split current transformer often encounters various problems in practical applications. The following summarizes several common faults and treatment methods in transformer applications:   1. Insulation caused by thermal breakdown.   Jewelry can accept high-voltage split current transformers with better stability, but in individual cases, when the current is large, but due to the high voltage, a higher insulation medium temperature will be generated. Once the acceptable temperature is exceeded, they can raise high-temperature insulation materials. Failure, resulting in split current transformer failure.   2. Problems caused by partial discharge.   The main capacitor of the 220kV normally open jewelry split current transformer is evenly distributed, but if the process does not meet the specifications, due to the stability of the process, the capacitor plate will not meet the requirements, which will cause the surrounding insulation to loosen. If it is not grasped well, it will cause uneven capacitor screen dislocation, U-shaped clips, because the credit card is too tight, the insulation will be deformed, the integrated bubbles and it is easy to change the voltage distribution, which will make the field strength of the other capacitor screen higher than the other, resulting in partial discharge, if not tested and handled in time, capacitor core rod failure will occur.   3. Humid environment.   Due to its poor quality, the gem of the internal open-close current transformer can produce intense discharge. The liquid produced in a humid environment will accumulate at the bottom of the capacitor core rod, so the curved part of the capacitor core rod becomes a heat-insulating material. The effect is very poor. Because they are in working condition for a long time, it is easy to form a capacitor core rod synthesis, which makes it produce power problems.   4. Reasons for insufficient drying and degassing.   CT needs to stop the vacuum oil filling project, otherwise the gas cannot be discharged and the vacuum state cannot be formed. In addition, the short degassing time leads to unclean degassing. Under the dual action of voltage and temperature, the current sensing device will heat up from time to time, causing mobile phone aging and failure, causing problems.   5. Personnel use errors.   The open-close current transformer is a relatively common fault, which is more likely to be caused by personnel, mainly due to personnel use errors, which together lead to loosening due to poor quality, secondary winding open circuit and other reasons during the vacuum oil stop process. , These uses will only cause partial overheating or discharge of the local power system. The emergence of these conditions will cause abnormal results of oil-soluble gas chromatography analysis.

The secondary grounding of the split current transformer refers to the grounding of the secondary S2 terminal of the current transformer or the grounding of the N terminal of the voltage transformer. The secondary and primary windings of the split current transformer only need to be grounded at a single point. Before grounding, the secondary winding has no potential contact with the earth. After grounding, the split current transformer will not form a loop with the ground, and the current will not flow to the ground during normal operation. When the insulation layer between the primary winding and the secondary winding is damaged, the primary high voltage is connected in series to the secondary circuit, and the primary high voltage is grounded at a fixed potential, so that the current flows to the ground. The secondary voltage of the split current transformer is grounded to ensure the secondary appearance and personal safety.   Note: The current transformer can only be grounded at one point. Regarding the secondary circuit of the current transformer, it is maintenance grounding. Grounding can avoid grounding current between multiple connection addresses and affect the information collected by the split current transformer.   1. What is the significance of a small stranding?   Answer: The secondary side of the current/voltage transformer is grounded at a certain point on its n line.   2. Why is the current transformer grounded only at one point?   Answer: The current at the two grounding points of the secondary circuit will be deflected. In other words, some current flows into the air through one point and then flows back through another point. Stop the current sampling of the connected maintenance/measurement/metering equipment, which may lead to incorrect maintenance use.   3. Why can the voltage transformer only be grounded at one point?   Answer: Two-point grounding will cause the neutral point potential of the secondary voltage circuit n line (ie N600) to shift. Stop the voltage sampling on all equipment, which can easily lead to incorrect maintenance use.

Transformers are an indispensable part of the power system. Its core function is to measure current or voltage and provide accurate primary current and voltage measurements for secondary maintenance and control equipment. Measurement accuracy, transient characteristics, stability and anti-interference performance are important indicators for measuring the quality of transformers. With the increase in voltage levels and the continuous increase in transmission capacity of power systems, the defects of traditional current transformers such as difficult insulation, easy saturation, poor transient performance and large size have gradually become prominent. In order to suppress the various shortcomings of traditional transformers and ensure the stable operation of the power grid, after years of technical research, flexible transformers have been successfully developed. The core equipment of this transformer adopts an all-optical structure, which can accurately transmit DC components, fundamental components and higher harmonics. One coil can measure currents of hundreds of thousands of amperes, and the instantaneous error of transient current is reduced to less than 10%, which is an effective improvement. It has high harmonic control accuracy and strong anti-electromagnetic interference ability, and is suitable for different industries such as large thermal power, nuclear power, gas, hydropower, etc. It is also suitable for rapid investigation and positioning of open cable faults in large cities. In order to limit the small space of the device, the volume and overweight of the transformer, the sensor ring is made into an optical cable by utilizing the soft and flexible characteristics of the sensor optical fiber, which can be installed on wires of all shapes. The weight of the surrounding area is reduced by more than 90%, with the advantages of sensitive equipment, cumbersome maintenance, and strong compliance. At the same time, the sensor optical fiber ring cannot cut off the original primary circuit in the station during installation, and can temporarily or permanently increase the measurement points in the system, so that the device stops running when the substation is running without causing power outages on the measured line. It is particularly suitable for substation transformation, power plants and other applications.   It is understood that the flexible transformer has been recognized by the industry as a promising new type of current transformer. After years of hard work, a complete product line of photoelectric current transformers has been formed, covering various voltage levels from 66kV to 800kV, covering column type, GIS type, bushing type, flexible type, etc., and many devices have been stably operated in smart substations.

1J 50 is a nickel-iron magnetic alloy with a nickel content of about 50% and an iron content of about 48%. 1J85 core It is derived from Permalloy. It has the characteristics of high magnetic permeability and high saturation magnetic flux density.   The alloy is melted in a vacuum medium, cast into an ingot, and then the metal sheet is hot forged, and then hot rolled, pickled, surface treated, and cold rolled into a finished product.   Ohmalloy-1J85 iron-nickel alloy (soft magnetic alloy) is mainly used in alternating magnetic fields, mainly for high magnetic yokes, sensitive relays, low-loss micromotors, small power transformers, pulse transformers, transistor switches, magnetic amplifiers, magnetic modulators, sensitive signal input and output transformers, heading magnetic heading instrument magnetic sensors, magnetic susceptibility measuring instrument components, precision instrument movable parts, and magnetic shielding and magnetic temperature compensation elements of stators.   They lose most of the magnetism they exhibit in a magnetic field. Chinese 1J46 / 1J50 / 1J77 / 1J79 / 1J85 with high magnetic permeability alloy is one such nickel-iron soft magnetic alloy offered by XAGY. Precision current transformers are used to step down high AC and DC currents to lower levels that can be directly measured by power analyzers. These systems can safely step down the current while maintaining the accuracy. Precision current transformers are used to step down high AC and DC currents to lower levels that can be directly measured by power analyzers. Nanocrystalline alloy strip application areas: switching power transformer and pulse transformer core power transformer, precision current transformer core leakage protection switch transformer application areas.

In the electronics industry, 1J85 cores are mainly low or medium alloys with high magnetic permeability and low coercivity. At high frequencies, materials with higher resistivity should be made on thin strips or alloys. Usually in sheet or strip form.   It is composed of nickel and molybdenum doped in different proportions of iron alloys. It is mainly used in two fields: energy conversion and information processing.   In the electronics industry, it is mainly low or medium alloys with high magnetic permeability and low coercivity. At high frequencies, materials with higher resistivity should be made on thin strips or alloys. Usually in sheet or strip form.   As a soft magnetic material used for exchange, due to the induction of AC magnetic eddy currents in the material, losses are caused. The smaller the resistance of the alloy, the greater the thickness, the higher the frequency of the AC magnetic field, the greater the eddy current, the greater the current loss, and the more magnetic loss. For this reason, the material needs to be made into a thinner sheet (tape) and an insulating layer is coated on its surface, or an oxide insulating layer is formed on the surface using certain methods. This type of alloy is often used for oxidation electrophoresis coating. Iron-nickel alloys are mainly used in alternating magnetic fields, mainly for yokes, relays, small power transformers and electromagnetic shielding. Permalloy is a nickel-iron magnetic alloy with a nickel content of about 80% and an iron content of about 20%. It is known for its relatively high magnetic permeability, which makes it useful as a core material in electrical and electronic equipment, and can also be used as a magnetic shielding material to shield magnetic fields.   Commercial Permalloy generally has a relative magnetic permeability of about 100,000, while ordinary steel has a relative magnetic permeability of 1J85. The 1J85 core metal shield is a soft ferromagnetic alloy, so it does not acquire remanence after the external magnetizing force is removed. It has high initial and maximum magnetic permeability with nominal hysteresis loss. It has small coercivity, rated core loss and small remanence. To obtain the required magnetic function, Mu metal should be heat treated at 1100℃ to 1180℃ in a dry hydrogen condition furnace below – 40℃ for 2 to 4 hours. This heat treatment increases the magnetic permeability by 40 times. Precision alloys have excellent physical and mechanical properties and are used in key components and devices of precision motors, electrical appliances, instrumentation, telecommunication equipment and precision machinery. According to the use and characteristics, precision alloys are divided into hard magnetic alloys, soft magnetic alloys, elastic alloys, expansion alloys, thermobimetals, resistance alloys, thermocouple alloys, conductive alloys, electrical contact alloys, shape memory alloys, superconducting alloys and so on. The main part of the fluxgate sensor is the magnetic core, whose hysteresis characteristics affect the performance of the sensor. When modeling a fluxgate sensor for design purposes, a prepared model of the core's hysteresis characteristics is required to achieve good agreement between the modeled and experimental data.   Zero-phase current transformer, power inverter, precision current transformer, magnetic amplifier. Power transformer, choke, pulse transformer. Multipolar pulse transformer, DC voltage inverter, modem. Unipolar pulse transformer.

Induction coil, an electrical device used to produce an intermittent high voltage source. An induction coil consists of a soft cylindrical core of iron, on which are wound two coils: an inner or coil, with relatively few turns of copper wire, and a surrounding coil, with a large number of turns of fine copper wire. An interrupter is used to automatically make and break the current in the coil. This current magnetizes the sensor core and produces a large magnetic field throughout the induction coil. When the current in the coil begins, an induced electromotive force is generated in both the coil and the coil. The opposite electromotive force in the coil causes the current to gradually rise to its value. Therefore, when the current begins, the time rate of change of the magnetic field and the induced voltage in the coil is relatively small. On the other hand, when the current is interrupted, the magnetic field decreases, and a relatively large voltage is generated in the coil. This voltage can reach volts and lasts for the short time that the magnetic field changes. Therefore, the induction coil produces a large voltage that lasts for a short time and a small reverse voltage that lasts for a long time. The frequency of these changes is determined by the frequency of the interrupter. Theoretical and implementation issues of optimizing induction coil magnetometers. The optimization is based on a simple magnetic model of the source, the induction coil and the current-to-voltage converter. The electrical model and characteristic equations required for the optimization procedure have been derived from mainstream theory. The equations have been modified for use in computer design. The program enables the signal-to-noise ratio of the magnetometer. The results have been validated by building and measuring optimized magnetometers and their parameters. The theory has also been used to construct a differential magnetometer, which significantly improves the performance of single-coil magnetometers in magnetically noisy environments.

1. Magnetic flux High U has low magnetic saturation, that is, the magnetic core can withstand large current at low frequency. The larger the current, the greater the inductive reactance changes with the current and becomes capacitive reactance. The heating of the magnetic core winding means that the core loss is too large, and the power is converted into heat energy instead of magnetic energy, and the energy is consumed. Usually, the nickel core has a wide bandwidth, and there is a balance between Q value and U. The higher the U value, the lower the Q value, and vice versa. It is difficult to work at low frequency with U value, but the loss is small. It is easier to work at low frequency with high U value, but the core loss is too large, the power loss is also large, and it is basically difficult to work continuously. Using a magnetic core winding with a U value of 400 should greatly reduce the magnetic loss. Although the inductance is a bit low, it can be solved by increasing the number of winding coils. Taking a 1:4 transformer as an example, the primary of 1 coil is changed to two coils; the secondary of 2 coils is changed to 4 coils, so the total length of the winding should be doubled, and the high transmission frequency should also be reduced accordingly. 2. Curie temperature Some cheap magnetic core windings have a Curie temperature of 165℃. When this temperature is reached, they lose their magnetism immediately, just like air medium. After returning to room temperature, the magnetic properties change permanently, and the magnetic permeability decreases by 10%. If the working temperature of the magnetic material used in the output transformer of the magnetic ring exceeds the Curie temperature, the output power tube can be burned in a moment. The Curie temperature data of imported -61 and -43 materials are unknown. The domestic NXO-100 is 260℃, and the R-400 is 350℃. The point where the output power starts to decrease is the temperature limit of the magnetic ring. From the past experimental results, at 55 degrees, those EMI magnetic rings have not yet experienced a decrease in output power. 3. Working frequency The material of each magnetic core determines its optimal working frequency, so it is necessary to select the material of the magnetic core according to the specific frequency. For example, the material of NXO-100 has a magnetic flux of 100 and a working frequency of 15MHZ. The magnetic ring made of NXO-80 material has a magnetic flux of 80 and a working frequency of 30MHZ. The magnetic ring with low working frequency will have great loss and heat when it is forced to work at a high frequency. When the heat of the magnetic ring exceeds the Curie temperature, the electrical performance will change suddenly and it will not work normally. In summary, to choose the right magnetic ring, it is not enough to look at the appearance or volume. It is necessary to understand its actual parameters. Otherwise, when problems occur, such as high standing wave, too narrow bandwidth, severe heating or burning of the magnetic ring, etc., you don’t know where the cause comes from.