Because the motor winding is in-phase and out of phase, there will be mutual attraction and repulsion force between the two bars of the adjacent coil at the end. In order to avoid the displacement caused by the force, it is necessary to fix the end. In the side gap between adjacent winding bars, polyester rope with similar thickness and gap size is selected to bind tightly.
At present, the stator of high voltage motor mostly adopts VPI whole immersion process. Its insulation structure is that the coil is wrapped with mica tape, the end of the coil is bound with polyester glass rope, and the coil and end hoop are bound with rope force, but it cannot be too tight, so as to prevent the insulation damage in different degrees and reduce the insulation performance. When the coil is heated according to the process requirements, the insulation at the end of the coil near the nose will be softened. This will damage the insulation and affect the service life.
Due to the large pitch and large inter pole distance of high-speed motor, the stator winding generally has the characteristics of long end size and large bell mouth. Some use large and small coils, the end of the inner circle coil is wavy, and the gap between the lower and upper layers is very small. Therefore, a layer of 4-5mm thick polyester felt can be wrapped on the coil end hoop insulation to play a role of cushion between coil and coil. Because polyester felt is soft and has a certain amount of compression, it can make the coil insulation of wire embedding binding no longer be compressed by the end hoop, at the same time, it also increases the contact area at the binding place, which ensures the close contact between the coil and the end hoop. After the winding is cured with paint, it is conducive to the end fixing in radial and tangential direction.
Detailed Situation and Current Situation Interpretation of Energy-saving Motor
As we all know, energy-saving motor has a wide range of uses. It is the most popular new energy-saving motor product in China and the world. The following is the idea of energy-saving motor. Let's take a look at it in the future.
Drive fan, pump, compressor, machine tool, belt and other equipment. It is used in metallurgy, petrochemical, chemical industry, coal, building materials, public utilities, household appliances and other industries. This is the largest electricity equipment in the world, accounting for more than 60% of the total social electricity consumption and more than 60% of the total industrial power consumption, about 75% of the electricity. In recent years, with the support of national policies, China's automobile energy efficiency has been improved.
But in general, China's energy efficiency level is still very low, and the average level of motor efficiency is 3-5 percentage points lower than that of foreign countries. The operating efficiency of motor system is 10% lower than that of foreign advanced level because of the large number of low efficiency motors in use. Huge waste of power and energy, motor is widely used in blower, pump, blower, compressor, refrigerator, machine tool, transmission and other fields. The end energy of electrical equipment such as belt and other mechanical transmission devices is large.
“Simo Motor” Statistics show that in 2000, the annual power consumption of various types of engines in China reached 238 million kilowatts, accounting for 57% of the national power consumption, which is different from the name of "big consumer". The motor consumes a lot of energy and has great energy saving potential. At present, China's engine power consumption is about 1.7 billion kilowatts, and the total power consumption is about 1.7 billion kilowatts.
The electricity consumption is about 3 mega kwh, accounting for 64% of the total social electricity consumption, of which the industrial power consumption is 2.6 kwh. Several mega kilowatt hours account for about 75% of industrial electricity consumption. Countries and international organizations around the world improve the energy efficiency of automobiles. As an important energy-saving strategy, the energy-saving of motor system has attracted worldwide attention.
In recent years, with the support of national policies, China's automobile energy efficiency level has been improved, but on the whole, China's automobile energy efficiency level has improved. This level is still very low. It is estimated that every 1% increase in the energy efficiency of automobiles in the industrial sector can save electricity consumption every year, about 26 billion degrees. Through the promotion of high efficiency motor, eliminate the low efficiency motor in use, transform and manufacture the low efficiency 0 x 642, 0 x 642 system can efficiently match and conduct energy-saving transformation according to its load characteristics and operating conditions.
The efficiency of the motor system is increased by 5% ~ 8%, and the annual power saving reaches 130 ~ 230 billion kwh, which is equivalent to the motor system. Three Gorges power station generates electricity. At present, there are the following main problems in the application of motors and systems in China.
Question: The proportion of high efficiency motor is below 5%. The energy efficiency level of a large number of motors is lower than the national mandatory performance efficiency standard (GB 18613-2012).The system matching with fixed value lower than 3-5 percentage points is unreasonable, "Malaysia vehicle" phenomenon is serious, and the equipment operates at low load for a long time. The regulation mode of energy-saving motor system is backward, many fans and pumps adopt mechanical regulation mode. The operation efficiency of fans, pumps, compressors and other equipment systems is 10% lower than that of foreign advanced level. In the motor energy-saving transformation, the most common problem is that we often install the motor and driver.