Currently small and medium inverter, many of them are using the PWM control mode. His carrier frequency of about a few thousand to tens of kilohertz, which makes the motor stator windings must withstand high voltage rise rate, equivalent to the steepness of the motor exert a great impact on the voltage, so that the motor turn insulation withstand more ordeal. This article from the motor efficiency and temperature issues, motor insulation strength problem, harmonic electromagnetic noise and vibration motor on five aspects of frequent start and braking ability to adapt to a low speed when the inverter cooling issues to discuss on Effect of the motor. 1, the motor efficiency and temperature regardless of the kind of problems in the form of the drive, in the operation were different degrees of harmonic voltage and current air compressor repair, the motor running in a non-sinusoidal voltage and current. Refuse to information on a sine wave PWM inverter current widespread use, for example, the low-order harmonics essentially zero, and the rest is larger than the carrier frequency of about twice as high harmonic component is: 2u + 1 (u the modulation ratio). Higher harmonics can cause motor stator copper losses, rotor copper (aluminum) consumption, an additional increase in loss and iron loss, most notably the rotor copper (aluminum) consumption. 2, the dielectric strength of the motor inverter compressor problem at present SMEs, many of them are using the PWM control mode. His carrier frequency of about a few thousand to tens of kilohertz air compressor parts, which makes the motor stator windings must withstand high voltage rise rate, equivalent to the steepness of the motor exert a great impact on the voltage, so that the motor turns between the insulation to withstand the ordeal relatively fast aging. 3, harmonic electromagnetic noise and vibration ordinary asynchronous motor using the inverter power supply, vibration and noise cause by electromagnetic, mechanical, ventilation and other factors caused become more complex. Intrinsic spatial harmonics of each sub-time harmonic electromagnetic motor power inverter section contains interfere with each other to form a variety of electromagnetic excitation force. 4, the motor for frequent starting and braking ability to adapt thanks to the inverter power supply, the motor can be started without the impact of current and voltage at low frequencies, and can use a variety of braking inverter supply rapid braking, frequent starting and braking to achieve the creation of the conditions for 5, the cooling problem of low speed when the first induction motor impedance less than ideal, when compared with the end of the power frequency, high power loss caused by harmonics compared Cottle large group of major screw compressors are mainly composed of the following systems: air flow system, lubricating oil flow systems, cooling systems, security systems, control systems and electrical wiring. Cottle · Screw Compressors group mainly compressor, motor, air filter, intake valves, oil barrels, air coolers, oil coolers pressure switch, one-way valves, cylinders, pressure gauge , automatic drainage, safety valves and other equipment components. Also in the air compressor system configuration mostly cold and dry and the air dryer. Volumetric efficiency is the ratio of the compressor and the theoretical actual gas volume to volume, expressed as a percentage. Compression efficiency is to give power to the theoretical power compression ratio required for quantitative real gas. Theoretical power can be isothermal adiabatic conditions or conditions to calculate. The corresponding percentages are available to determine the compression efficiency and representation. On steam drive or internal combustion engine driven compressors, mechanical efficiency is the ratio of the brake-horsepower compressor horsepower instructions splitters and the shaft. On a motor-driven compressor, the mechanical efficiency is the compression axis indicates power and the power ratio of the compressor cylinder. Expressed as a percentage. Air compressor repair, Qin Wei Air, the technology leader in Europe and America (certified), the compressor is provided by Compressor Co., Ltd., Xianyang Qin Wei. Xianyang Qin Wei Compressor Co. (www.xykyj.cn/) is Xianyang, compression, separation equipment leader, over the years, the company implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. Qin Wei Air leadership with the staff warmly welcome all inquiries negotiations to create Qin Wei Air a better future.