The inverter allows the motor drive system to achieve two wishes, one is to make the motor achieve higher efficiency operation; The second is to make the motor controllable and avoid the problem of big bulls pulling trolleys. However, the problem in front of the engineer is: there are so many types of motor loads, and the performance requirements for the equipped inverter are also very different, how to choose the right inverter for the motor?
The inverter is an electric transmission element used in frequency conversion technology and microelectronics technology to control the AC motor by changing the frequency and amplitude of the motor's working power supply.
In general, the selection of inverter should be considered according to the type of controlled object, speed regulation range, static speed accuracy, starting torque, etc., so that it can meet the process and production requirements at the same time, it is easy to use and economical.
The general experience is:
Choose how big the inverter is for the size of the motor, and sometimes it can be a larger size.
The power factor of the high-power inverter is only low, and it is best to install an AC reactor at the inlet end of the inverter.
In this way, one is to improve the power factor, and the other is to suppress high-frequency harmonics. If it is frequently started and braked, the brake unit and brake resistor should be installed.
If noise reduction is required, a water-cooled inverter is an option
If braking is required, it is necessary to choose a brake chopper and braking resistor, or a four-quadrant product can be selected, which can feed back energy to the grid and save electric energy;
If there is only DC power supply on site", you can choose a pure inverter product (using DC power supply) to drive the motor. The final basis for the selection of the inverter is that the current curve of the inverter includes the current curve of the mechanical load.