Woodworking engraving machine inverter related knowledge

    The frequency converter is an important part of the woodworking engraving machine. The following is a brief introduction to the knowledge of the inverter.
    The frequency converter is a power control device that converts the power frequency power source into another frequency by using the on/off function of the power semiconductor device.
    The main circuit of the inverter can be roughly divided into two categories: 1 voltage type inverter, this type is the inverter that converts the DC of the voltage source into AC, the filter of the DC loop is the capacitor; 2 The current type inverter, this type is The DC of the current source is converted into an AC inverter, and its DC loop is filtered by a stone inductor.
    The inverter is operated, and the frequency and voltage are increased correspondingly with the acceleration of the motor. The starting current is limited to 150% of the rated current (125% to 200% depending on the model). When starting directly with the commercial frequency power supply, the starting current is 6 to 7 times, so mechanical and electrical impact will occur. It can be started smoothly with the inverter drive (starting time becomes longer). The starting current is 1.2~1.5 times of the rated current, and the starting torque is 70%~120% of rated torque. For the inverter with automatic torque boosting function, the starting torque is 100% or more, and it can start at full load.

     The voltage of the inverter changes in proportion to the current. The torque of the asynchronous motor is generated by the interaction between the magnetic flux of the motor and the current flowing through the rotor. At the rated frequency, if the voltage is constant and only the frequency is reduced, the magnetic flux is too large, and the magnetic circuit is saturated. The motor will be burned. Therefore, the frequency and voltage should be changed in proportion, that is, the frequency of the inverter is controlled while changing the frequency, so that the magnetic flux of the motor is kept constant to avoid the occurrence of weak magnetic and magnetic saturation. This type of control is mostly used for energy-saving inverters such as fans and pumps.