With the rapid development of power electronics technology and new semiconductor devices, AC speed regulation technology has been continuously improved and enhanced. The gradually improved frequency converter has been widely used in AC motors with its good output waveform and excellent performance-price ratio. For example: large motors used for steel rolling in steel mills, small and medium-sized roller motors, traction motors for railways and urban rail transit, elevator motors, hoisting motors for container lifting equipment, motors for water pumps and fans, compressors, motors for household appliances, etc., have successively used AC variable frequency speed regulation motors and achieved good results.
The axial and radial dimensions of the motor basically determine its overall appearance. Slender motors and short and fat motors may have some technical difficulties in the manufacturing process, and the relative error may have a greater impact on the motor performance. For variable frequency motors, the resonance factor must also be considered, which affects the motor's operating performance.
Compared with industrial frequency motors, variable frequency motors must have high rotor balance quality, high machining accuracy of mechanical parts, and special high-precision bearings to ensure that the vibration performance under high-speed operation meets the requirements. To this end, the axial length of the variable frequency motor should be controlled to prevent objective factors of high-speed vibration caused by too long axial size. Customers who have used variable frequency motors may know that in most cases, severe vibration will occur in a certain frequency band, especially when the frequency modulation range is wide. This is what we call resonance. Resonance is also called "resonance". It is the phenomenon that the amplitude of the oscillation system increases sharply when the frequency of the external force is the same as or very close to the natural oscillation frequency of the system under the action of periodic external forces. The frequency when resonance occurs is called "resonance frequency".
Considering the fact that variable frequency motors have resonance and wide range of speed regulation, the magnetic field design of variable frequency motors should be further optimized to suppress high-order harmonic magnetic fields and maximize the requirements of broadband, energy saving and low noise. In particular, the selection of frequency converters should be combined with the actual operating conditions and matched with appropriate high-quality frequency converters.
low voltage electric motor, Ex motor, Motor manufacturers in China, three phase induction motor, SIMO motor