Research and development background and characteristics of precision current transformer winding machine
Research and development background and characteristics of precision current transformer winding machine
The precision of coil in current transformer is very important, because it directly affects the accuracy of current measurement and the reliable operation of power system. The specific importance of coil accuracy is reflected in the following aspects.
Electrical energy metering: In a power system, accurate measurement of current is the key to calculating energy consumption. If the coil in the current transformer is not accurate, it will lead to an error in the measurement of electrical energy, which can lead to a miscalculation of energy costs, with possible financial implications for both the utility and the consumer.
Fault detection: The current transformer is used to monitor the current level to detect abnormal conditions in the power system, such as short circuit and overload. If the accuracy of the coil is not high, it may lead to false positives or neglect of potential faults, which affects the reliability of the power system.
Overcurrent protection: Current transformers play a key role in overcurrent protection devices, detecting overcurrent events and triggering circuit breakers or other protective devices. The accuracy of the coil directly affects whether the overcurrent can be accurately detected to ensure the safety of the power system.
Load management: The load management of a power system requires accurate measurement of current in order to make reasonable load distribution and adjustment. If the precision of the coil is not high, it may lead to unbalanced load distribution, affecting the efficiency and stability of the power system.
Automated control: In modern power systems, automated control systems rely on accurate current measurement data for real-time adjustment and control. The precision of the coil is critical to the response speed and performance of the system.
Waveform analysis: Current transformers are also used for power quality analysis, including harmonic analysis. The precision of the coil determines the accurate analysis of the current waveform, which helps to solve the power quality problem.
In short, coil accuracy is critical to the performance and application of current transformers. High-precision coils ensure the accuracy of current measurements, thereby maintaining the reliability, stability and efficiency of the power system. Therefore, when selecting and using the current transformer, it is very important to ensure that the accuracy of the coil meets the application requirements.
Through the above introduction, we already know the transformer coil for the transformer described an impact and its importance, then the following content, let's introduce, how to obtain high-precision transformer coil, to this end, we have developed a high-precision transformer coil winding machine. The picture shown in this article is the coil of a type c current transformer.
As can be seen from the picture of this product, the core of a C-type current transformer is cut by a rectangular rectangular core. The customer then requested that the coil be wound directly around the long side of this cut core. The enamelled wire of this product is 0.2 mm in diameter and 2700 turns. Because it is a mass production, it requires high precision, does not allow for chaotic lines, a lot of layers are wound, and requires stable production.
We carefully listen to and collect the needs of customers, targeted to develop the transformer winding machine they need, and successfully meet the needs of customers. On this basis, the transformer winding machine is summarized.
High precision current transformer coil winding machine is a kind of equipment specially used for manufacturing current transformer coil, it plays a crucial role in the manufacturing process of current transformer. People in the actual high-precision transformer production, for the current transformer coil winding machine.
Automatic production: High-precision current transformer coil winding machine using automation technology, can automatically complete the coil winding process. This automated production method increases production efficiency, reduces labor costs, and reduces the possibility of human error.
Accuracy and consistency: The high accuracy of the transformer winding machine ensures that each current transformer coil has consistent characteristics. Specific performance in the number of turns accurate, orderly, tension stability of these three aspects. This is essential for the accuracy of current measurements, especially in applications where high precision is required.
High-speed winding: High-precision current transformer coil winding machine usually has high-speed winding function, can complete a large number of coil manufacturing in a short time. This is very important for mass production of current transformers.
Adjustment flexibility: The winding machine usually has adjustable parameters, such as the number of turns of the coil, the wire diameter and the winding speed. This allows the production process to be flexibly adjusted to different models and specifications of current transformers.
Customization ability: Because different current transformers may have different specifications and requirements, the corresponding fixture and even the equipment structure are different, high-precision current transformer coil winding machine usually has a certain customization ability to meet the needs of different customers.
In short, the high-precision current transformer coil winding machine plays an important role in the current transformer manufacturing, they ensure the performance and accuracy of the current transformer through the automatic, high-speed and accurate coil winding process. These machines have a wide range of applications in power systems, including power metering, power protection, power quality analysis and other fields.
Now let's briefly introduce the current transformer itself.
Current transformer An instrument that converts a large current into a small one. Like magic, it has an iron core and a bunch of coils. One pile of coils is wound around the line to measure the current, while another pile of coils is strung around the measuring instrument and the protection device. The secondary side of the CT is always closed, so it acts like a super short circuit.
Okay, now let's talk about what's going on. On the power supply line, the size of a current ranges from a few amps to tens of thousands of amPs. But we usually need a stable secondary current to measure, protect and control the power system, because the primary voltage is usually high and direct measurement is very dangerous. This is where the current transformer comes in.
The current transformer has two windings: the primary side (few turns) is strung in the current line to be measured, and the secondary side (more turns) is strung in the measuring instrument and protection loop. The ratio of the primary side current (I1) to the secondary side current (I2) of the current transformer is called the actual current ratio K. For pointer ammeters, the secondary current of the current transformer is usually in the ampere-scale, while for digital meters, their sampled signal is usually in the milliampere-scale.
The model of the current transformer is usually indicated by letters and numbers, such as L for current transformer. The letters in the model number can indicate its type, installation, insulation, and so on.
As for the technical parameters, rated capacity, primary rated current, secondary rated current, rated current ratio, etc., are very important indicators. There are many types of current transformers, such as measurement and protection, and their working principles and requirements are not the same.
Finally, it should be noted that electronic current transformers are gradually emerging, and they have the advantages of diamagnetic saturation, low power consumption, wide band, etc., so in the power system, current transformers are a very critical component. Hopefully this colloquial explanation will help you better understand the principle and application of current transformers.
Let's talk about how to choose the current transformer!
First of all, the rated voltage is higher than the rated voltage of the line, which is very important.
Next, the variable ratio. The ratio of the current transformer should be calculated according to the primary load. There are generally a variety of specifications to choose from, such as 20, 30, 40, 50, 75, 100, 150 and 2 x a/C. Where 2×a/C indicates that the same product has two current ratios, which can be switched by changing the wiring mode of the connection piece. In general, if the load current in the line is 350A, then you should choose a ratio of 400/5. If it is used for protection, a larger variable ratio can be selected to ensure accuracy.
Next is the choice of the level of accuracy, which is determined according to the accuracy requirements of the measurement. The accuracy level of the current transformer used for billing and metering is not less than 0.5, and the ammeter used to monitor the current of the incoming and outgoing line circuit should choose a current transformer of 1.0 to 3.0.
The second is the verification of dynamic stability and thermal stability, which can be verified according to the following formula:
Dynamic stability check: Kes×I1N ≥ ISh
Thermal stability check: (KtI1n)2t ≥ I∞tima
Then there is the rated capacity, the secondary rated capacity of the current transformer is greater than the actual secondary load, usually 25% to 100% of the secondary rated capacity. This can affect the accuracy of the measurement or control, so be aware.
Finally, some considerations for use:
The wiring should comply with the series principle, the primary side is connected in series with the circuit under test, and the secondary side is connected in series with all instrument loads.
Choose the appropriate ratio according to the size of the measured current, otherwise the error will increase.
The secondary side must be grounded to prevent the high voltage of the primary side from entering the secondary side when the insulation is damaged, resulting in a safety accident.
Never open the secondary side, otherwise there will be high voltage danger, and do not disassemble ammeter or relay equipment without bypass during operation.
In short, when the current transformer is working normally, the secondary side is used in series with current coils such as measuring instruments and relays, so it should be operated carefully to ensure safety.
Related Post
Study on the control of the speed curve of the coiling machine for precision coiling machine
Your factory is using a traditional winding machine, your wire machine structure is reasonable, high mechanical accuracy, the motor is also used a big brand of motor, but in the winding of precision coils, there will be a high defect rate, you carefully analyze before improving various factors - equipment structure, processing accuracy, tooling accuracy, skeleton accuracy, enamel wire quality, tension control, etc. But it still doesn't solve the problem. But to tell you that it's not just a hardware problem, but an algorithm problem, may surprise you. Because in your opinion, every time the spool is transferred, the spool has a corresponding response, but in fact, you may not have considered that in the winding process of the precision coil, the wire guide pin is connected at both ends of the coil, and the sudden change in speed may cause the coil to cross the line and be raised. These defects can degrade the performance of the coil.
To solve this problem, we propose an acceleration and deceleration method based on 5-segment S-curve. The algorithm uses linear acceleration or deceleration at the end and end of the line motion control to help reduce coil defects. We first verify the feasibility of the algorithm by using ADAMS software. The software simulates the motion of the precision winding coil and obtains the velocity curve and displacement curve during the motion. Later, the experimental results show that the method of adopting S-curve in the alignment speed control can reduce the coil defect by up to 50%. This shows that the 5-section S-curve motion control algorithm is a promising method to improve the precision and efficiency of the winding process of electric precision coils. By using this algorithm, coil manufacturers can reduce the risk of coil defects and improve coil performance.
Winding machine is a special production equipment for precision winding coils. They can be divided into stator winding machine, flying fork winding machine, ring winding machine and flat winding machine according to the working mode and object. Different types of equipment are suitable for the production of different objects. For example, the stator winding machine is mainly used to produce motor stator coils, while the parallel winding machine is used to produce electromagnetic switching coils.
Ordinary algorithm of parallel winding machine in the production of precision winding coil products, although our mechanical structure, parts processing accuracy has been done very well, but often there is a problem of low wiring accuracy. In the process of winding a line coil, there are two main movements, one is the rotating movement of the skeleton, which is called winding movement, and the other is the translation movement of the guide needle, which is called wiring movement, and wiring transport is matched with winding movement. After years of technical accumulation, we analyze that the leading role in the alignment accuracy is the alignment movement of the guide needle. Therefore, if you want to improve the alignment accuracy of the coil, you need to optimize the alignment movement of the guide pin.
In fact, we have always believed that the winding machine is equivalent to the lathe in the electrical industry, its importance is self-evident, so for its accuracy, there have been many experts and scholars to study this.
Some people studied the mathematical model of precise alignment based on axial pressure compensation around the axis in the process of alignment. The axial pressure was used to improve the alignment regularity of the coil, and the mathematical model was established according to the analysis of the end point of the coil alignment, which improved the alignment accuracy of the coil.
Some people use the 5-section S-curve control algorithm and the 7-section S-curve control algorithm respectively in the research. In motion control, the 7-section S-curve is more complicated than the 5-section S-curve control. This method has achieved more results in the field of CNC machining, but it is not mature in the field of winding machine.
The tension instability caused by the friction between the enamelled wire and the conductor nozzle during coil winding has been studied, which leads to the uneven wiring of the coil and the breakage of the enamelled wire.
Some people have studied the low efficiency of the winding machine in the traditional winding control because of the inertia error in the process of the winding machine. Instead, the servo motion wiring and the inertia error supplement are used to improve the control efficiency of the winding machine.
PLC control is commonly used in the winding machine wiring control system, through PLC control servo motor can realize the winding machine wiring control, both PLC control stability and high precision servo motor advantages. However, there is a sudden impact of guide pin speed in the coil alignment of parallel winding machine, so it is necessary to further optimize the change of guide pin running speed to improve product quality and the smoothness of wire alignment speed. The S-curve algorithm is a kind of smooth transition of speed in the process of motion, which is often used in machining to solve the problem of breaking the tool caused by speed impact and improve the precision of machining products. In the winding machine, the speed of the guide needle can be changed into an arc smooth transition by controlling the movement track of the guide needle, improving the alignment accuracy and product quality.
To sum up, an algorithm based on 5-segment S-curve motion control is proposed to solve the problem of velocity shock in the process of coil alignment by analyzing the law of coil alignment. ADAMS software is used to simulate the trajectory of the guide pin to verify the feasibility of the algorithm. And the application of the example proves that the 5-section S-shaped curve can effectively solve the phenomenon of crossing and protruding in the process of winding, and improve the precision of winding.
Coil wiring principle
The winding method is flat winding, that is, the enameled wire moves synchronously with the guide pin and always keeps perpendicular to the skeleton during winding. The frame is driven by the winding motor with the guide needle movement, the enameled wire is wound on the skeleton, in which the guide needle is located in the wiring arrangement mechanism and the winding mechanism are two independent mechanisms. The winding mechanism is divided into three stages according to the motion process of the guide pin, namely acceleration and deceleration stage, uniform speed stage and end point return stage. The acceleration and deceleration stage can be divided into two parts: acceleration stage and deceleration stage. In the early stage of the alignment movement, the guide pin speed from zero to uniform speed belongs to the acceleration stage. At the end of the alignment movement, the process of decelerating until the speed reaches zero is a deceleration stage. The middle constant velocity stage is the constant velocity motion stage of the guiding needle. The terminal reentry stage is a process in which the guide needle accelerates backward again after slowing down and stopping. Here we explain:
Acceleration and deceleration stage
In order to arrange the lines evenly, the two movements of guide pin movement and skeleton rotation should meet certain coordination relations during acceleration and deceleration stage. The time for the guide needle to move one diametral width distance must be equal to the time for the skeleton to rotate once, that is, the guide needle to move just one diametral distance when the skeleton rotates once.
U-shaped core winding machine
Transformer coil winding machine
Stable, high-speed and safe U-shaped core coil winding machine
The U-shaped coil winding machine is suitable for the winding of the bottom edge of the U-shaped core.Usually, the center of the U-shaped core is difficult to coincide with the rotation axis of the winding machine, resulting in a large vibration of the winding machine. , Affecting efficiency.
This type of winding machine developed by our company does not rotate the U-shaped iron core, only reciprocates, and rotates around the product to reduce vibration and improve efficiency.
With the optimized clamping method, it only takes 2 seconds to complete the clamping.
Therefore, the rotating parts of this type of machine have a large diameter and a high speed.There are similar machines on the market, and the larger ones do not have a protective cover. Safety accidents often occur.This machine of the company has a protective cover design.
Transformer winding machine
Transformer winding machine:
Similar to transformers, current transformers also work according to the principle of electromagnetic induction. The transformer transforms voltage and the current transformer transforms current. The current transformer is connected to the winding of the measured current (the number of turns is N1), called the primary winding (or primary winding, primary winding); the winding connected to the measuring instrument (the number of turns is N2) is called the secondary winding (or secondary side) Winding, secondary winding).
This ring current transformer winding machine is generally used to wind small size current transformers. The characteristics of small size current transformers are generally wire diameter of enameled wire between 0.11-0.19mm, and the number of turns is large.
It requires accurate turns and fast winding speed.
REPOSAL this machine is fast and stable, and the speed reaches 1400RPM. Because it is stable, it can realize the operation of multiple ring current transformer winding machines by one person.
Transformer winding crepe paper | Transformer winding crepe paper | Transformer winding crepe paper
Transformer insulating crepe paper has good mechanical strength, high withstand voltage strength, wrinkles on the surface, and a certain degree of toughness. Moreover, it is easy to cut. After the transformer is wound and formed, it still maintains a certain strength in the oil immersion of the rear tooling. This feature can very well protect the enameled wire of the transformer from being squeezed and broken, that is, it meets the insulation requirements. It also meets the mechanical performance requirements.
Therefore, it is widely used for transformer insulation. Generally used in transformers, but less used in transformers, because the core structure of transformers is annular, because the surface of the insulating crepe paper has wrinkles and friction is large, so the annular wrapping machine is used. Winding is more difficult, so in general, if crepe paper is required for the transformer coil, manual winding is used. We have successfully overcome this problem by improving the details.
Detailed explanation of the operation instructions of the transformer winding machine
Detailed explanation of the operation instructions of the transformer winding machine
Transformer winding machine is a special winding equipment for winding enameled coils of transformers. During the winding process of enameled coils of transformers, winding enameled wire equipment is divided according to the specifications of the transformer. Enameled wire winding machine and foil enameled coil winding machine; there are vertical winding machines and horizontal winding machines for winding enameled coils of large power transformers.
1. Structural characteristics of transformer winding machine:
1. The mechanical transmission part of the winding machine is located inside the headboard, and the electrical part is installed on the top of the headboard. The three-phase asynchronous motor is driven by the frequency converter to realize the linear change of the spindle speed.
2. The winding machine adopts stepless speed regulation, and the controller outputs 0-10V analog voltage, which is connected to the inverter. By means of percentage, there are a total of 100 gears, which can be counted accurately, and can also be counted in reverse to automatically stop.
3. The winding machine can count reversibly, and is equipped with an electromagnetic brake device to prevent reversing when winding the enameled wire to stop, and ensure that the automatic counting will not produce errors. If you need to manually reverse, you can manually press the brake button to release, and the manual rotation can also count.