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In the past year, I thank all new and old customers for their trust and support in CANWIN. As the Chinese Lunar New Year approaches，CANWIN wishes all new and old customers good luck, good health and happy family! In the new year, we will continue to bring more and better transformers and intelligent equipment and better pre-sale and after-sales services to new and old customers at home and abroad, and create more value for the society! Let's work together for a better future!

To deal with transformer short circuit accident in daily operation, it is necessary to find out the essence of the problem through inspection and test. When the transformer suffers from sudden short circuit, the high and low voltage sides will be subject to large short circuit current. In the short time when the circuit breaker has no time to disconnect, the electric force generated by the short circuit current, which is proportional to the square of the current, will act on the transformer winding. This electric force can be divided into radial force and axial force. In case of short circuit, the radial force acting on the winding will make the HV winding subject to tension and the LV winding subject to pressure. Since the winding is circular, the circular object is more easily deformed under pressure than under tension, so the low-voltage winding is more easily deformed. The axial force generated in case of sudden short circuit compresses the winding and causes axial displacement of high and low voltage windings. The axial force also acts on the iron core and clamps. Therefore, when the transformer suffers from sudden short circuit, the low-voltage winding and balance winding are most likely to be deformed, followed by the high-voltage winding, iron core and clamp. In addition to checking the main windings, iron cores, clamps and other parts after the transformer short-circuit accident, a series of related problems should also be paid attention to during the handling process:

[Good News] Guangdong Canwin Intelligent Equipment Manufacturing Co., LTD., founded in 2002, won the 2020 China Science and Technology Progress Award and Guangdong Provincial Technology Invention Award for its key Technology and Equipment for Precision and Efficient Cutting of High-end Metal Plate and Belt. In addition, the push and pull material technology applied by Guangdong Canwin for cutting silicon steel sheet material below 0.18mm in 2014 has won the national invention patent [Patent Number: CN103990731A], which has become the standard configuration of thin plate shear transverse shear line in the electrical equipment industry. Recently, Guangdong Canwin launched another subversive product, double robot six-station automatic laminating horizontal cutting line. The product is the No.1unit in China, but also the No.1unit in the world. Its key technology is to grab five pieces at a time (double robot is equivalent to ten pieces at a time), can fold six transformer cores. [has applied for a number of patents] This technology ends up the history of the traditional transverse cutting line only cutting function without stacking function, and is the turning point for leading the technology take-off of the global electrical equipment industry!

The transformer is a static device in continuous operation, which is relatively reliable in operation and has less chance of failure. However, since most of the transformers are installed outdoors, and are affected by the load during operation and the short-circuit fault of the power system, various faults and abnormal situations inevitably occur during operation.

The power loss of the transformer is divided into iron loss and copper loss. Iron loss is also called no-load loss, which is its fixed loss. It is actually the loss generated by the iron core (also called iron core loss, and copper loss is also called load loss).

Transformer faults can be divided into internal faults and external faults.Transformer internal faults refer to the faults that occur in the transformer oil tank, including phase-to-phase short circuit of each winding, inter-turn short circuit of winding, short circuit fault between winding and iron core, single-phase grounding fault of single-phase winding or lead-out wire passing through the shell, winding disconnection fault, etc. Transformer external faults refer to various faults that occur on the external insulating bushing of the transformer oil tank and its lead-out wires, including single-phase grounding short-circuits and phase-to-phase short-circuits between lead-out wires caused by flashover or broken insulating bushings.

01 Inrush currentWhen a transformer is first energized, a phenomenon called magnetizing inrush occurs. Although inrush currents are generally not as disruptive as fault currents, the duration of magnetizing inrush currents is on the order of seconds (compared to periods with fault currents).

During construction, dry transformer and oil transformer can be selected according to the space. Oil transformer can be selected when the space is large, and dry transformer can be selected when the space is crowded.

A new breakthrough in UHV technology! Successful test of new generation a million volt transformer.On Oct. 28, TBEA (20.730, -0.94, -4.34%) was informed that the new generation of direct outlet 1000kV AC extra-high voltage transformer produced by TBEA recently passed all the tests at one time, and TBEA became the first company in China to pass all the tests of the new generation of megavolt transformer at one time.In order to meet the high reliability of high-altitude equipment, TBEA set up a special research group and passed the product development at one time after many special demonstrations and guidance from the State Grid and industry experts.The product adopts a new direct outlet device for the first time and fixes it on the body, avoiding the risks brought by the process of disassembling and reassembling on site after the test of indirect outlet device; adopts a new coil insulation structure for the first time to further improve the insulation characteristics, short-circuit resistance, temperature rise distribution and workshop production process of the product, especially to meet the requirements of transformer temperature rise in high altitude areas; adopts a new oil tank explosion-proof design concept for the first time, significantly improving the transformer's explosion-proof performance. With the application of these new technologies, the technical performance of the new generation of mega-voltage transformers surpasses that of its predecessors, reducing the total loss by more than 80kW and significantly improving the energy efficiency level of the products.The successful test of the new generation of million volt transformer not only improves the safety and stability of China's AC transformer operation in high altitude areas, but also plays a very important role in the consumption of clean energy and ensuring the stable operation of the power grid.Source: China Science and Technology NetworkCANWIN also the equipment supplier for TBEA ，If you have demand for CRGO cutting machine and slitting line and transformers, welcome to contact us.

1. What are the consequences of different connection groups for parallel operation of transformers?Answer: When transformers of different connection groups are operated in parallel, the secondary circuit will generate voltage difference due to different secondary side voltages of transformers Δ U2, because the total phase difference in transformer connection is a multiple of 30 ° Δ The value of U2 is large. If the phase angle difference of the secondary side of the parallel transformer is 30 °, Δ The U2 value is 51.76% of the rated voltage. If the short-circuit voltage Uk of the transformer is 5.5%, the equalizing current can reach 4.7 times of the rated current, which may burn the transformer.A large phase difference produces a large equalizing current, which is not allowed. Therefore, transformers of different groups cannot operate in parallel.

The winding and iron core of the transformer are the main components for transmitting and transforming electromagnetic energy, and ensuring their safe operation is a problem that people are concerned about. Statistics show that the fault is caused by the iron core problem, accounting for the third place in the total transformer accident. The manufacturing department has paid attention to the defects of the transformer core, and has made technical improvements in the metal hose and stainless steel hose grounding monitoring of the iron core and ensuring a little grounding.

CANWIN The third-generation transformer core processing center was put into production as planned, and 10 sets of finished machines will be gradually put into the market!The third-generation machine adopts the mode of one shear and four punches, that is, the swing shear is used as the main shearing machine, which can cut angles of 45 degrees, 90 degrees, and 135 degrees, and can switch the angle during high-speed shearing;Four punches refer to two sets of V-shaped punches that can move laterally, and two sets of O-shaped punches that can move laterally and longitudinally at the same time. Action synthesis, one action is complete!The silicon steel sheet limit track of the third-generation machine adopts open track design, and the limit bearing adopts ceramic bearing, which is more convenient to clean and use;In addition, the third-generation machine also adopts the magnetic belt tension feeder uniquely designed by CANWIN, which is even better in details!