according toMotorThe staff introduced that explosion-proof motors are used in hazardous areas where there may be no information explosion hazard.The motor is an electromagnetic device that realizes the conversion or transmission of electric energy according to the law of electromagnetic induction.Explosion-proof motorsA type of motor that can be used in flammable and explosive plants, and it does not generate sparks during operation.Explosion-proof motors are mainly used in coal mines, oil and gas, petrochemical and chemical industries.In addition, it is also widely used in sectors such as textiles, metallurgy, city gas, transportation, grain and oil processing, papermaking, and medicine.Frequency conversion speed motorA general term for motors driven by frequency converters.In fact, the motor designed for the frequency converter is a special frequency conversion motor. The motor can achieve different speeds and torques under the drive of the frequency converter to adapt to the changes in the demand of the load.The development of explosion-proof motors has a shell, and its structure makes the motor truly represent the explosion or fire hazard. At present, more and more explosion-proof motors in our country are being used in major mechanical and electronic equipment.
With the use of explosion-proof motors in more and more industries, VFD applications are controlled in variable speed applications.In most cases, the VFD is installed in the hazardous area, just because from a safety point of view, a smaller amount of the variable speed drive is usually located in the hazardous area and the motor power cord, which is a better range.Also supports the cost of this approach: matching the explosion-proof environment certified VFD/motor assembly is bound to be more expensive, and it is not always rational in today's highly competitive global manufacturing market.
When the frequency converter technology and its important auxiliary teaching equipment are installed outside the Ex area, a safety management problem is overcome, but it does not necessarily overcome the traditional cultural problem that the use of variable speed drives can cause the heating of the motor in our country.The cause of the problem is the non-sinusoidal signal output of the VFD, which is always increasing as well as motor loss.In the past, when most explosion-proof motors passed the certification of learning sinusoidal power supply, the use of VFD may invalidate the certification of the motor, because the non-sinusoidal effect of the frequency converter moved the machine out of its operating environment parameter information.
When using a VFD to change the speed of an explosion-proof motor, a further consideration is their adverse effect on the cooling of the motor-unless some supplemental cooling method is provided.This is because when the inverter reduces the motor speed, the gas flow through the motor will decrease.The reduction in cooling capacity exacerbates the problem of harmonic losses.The combination of these two factors causes the motor to run hotter because its speed drops.
The problem of matching the operating system parameters of frequency converters and motors from different manufacturers in China means that corporate users can better use an integrated drive/motor assembly from a single manufacturer.The analysis of the results of the current extensive application testing work program in Brazil supports the benefits of this teaching method.These functional test technologies combine the electric motor with the new CFW-09 frequency converter, as well as the drive series of some other manufacturers.
The overall efficiency of testing is improving, and many support vector machine technologies provide obvious operational advantages.The combined effect of the SVM and VSD drive test packages for all motors to achieve a high total efficiency is about 97%.Even in the face of eccentric load apps, you can maintain this level of efficiency.
