Characteristics and advantages of variable frequency motor
 
Variable frequency speed regulation usually refers to such an electromechanical system: variable frequency speed regulation induction motor, frequency converter, programmable controller and other intelligent devices, terminal actuator and control software, which constitute an open-loop or closed-loop AC speed regulation system. This speed regulation system is replacing the traditional mechanical speed regulation and DC speed regulation scheme in an unprecedented situation, greatly improving the degree of mechanical automation and production efficiency, and making the equipment more and more miniaturized and intelligent.
 
Looking at the energy consumption of all motors in industrial applications, about 70% of motors are applied to fan and pump loads. The benefits of energy conservation and emission reduction of such loads are obvious: huge economic benefits and social effects of sustainable development. Just based on the above purpose, AC motor variable frequency speed regulation is widely used. For example, when the temperature of the variable frequency air conditioner is reduced, you only need to control the motor speed to reduce and reduce the output driving power.
 
In addition to energy saving and easy popularization and application, variable frequency speed regulation asynchronous motor has the advantage of soft start, so it is not necessary to evaluate the starting performance. The only key problem to be solved is to strengthen and improve the adaptability of the motor to non sine wave power supply.
 
The frequency converter we use mainly adopts AC-DC-AC mode (VVVF frequency conversion or vector control frequency conversion). First, the power frequency AC power supply is converted into DC power supply through rectifier, and then the DC power supply is converted into AC power supply with controllable frequency and voltage to supply the motor. The circuit of frequency converter is generally composed of rectifier, intermediate DC link, inverter and control. The rectifier part is a three-phase bridge uncontrollable rectifier, the inverter part is an IGBT three-phase bridge inverter, and the output is PWM waveform. The intermediate DC link is filtering, DC energy storage and buffered reactive power.
 
Variable frequency speed regulation has become the mainstream speed regulation scheme, which can be widely used in all walks of life. Especially with the increasingly wide application of frequency converter in the field of industrial control, the use of frequency conversion motor is becoming more and more widely. It can be said that because of the advantages of frequency conversion motor over ordinary motor in frequency conversion control, it is not difficult for us to see the figure of frequency conversion motor where frequency converter is used.