In order to better control the electric order picker reclaimer stacker, the order picker reclaimers are equipped with frequency converters. When classified according to the working mode of the main circuit, the inverters can be divided into voltage-type inverters and current-type inverters. The characteristic of the voltage type inverter is to convert the DC voltage source into the AC power source, and the characteristic of the current type inverter is to convert the DC current source to the AC power source.
① The voltage-type inverter of the electric order picker is to generate the DC voltage required by the inverter circuit from the rectifier circuit or the chopper circuit, and smooth it out through the capacitor of the intermediate circuit. The rectifier circuit and the DC intermediate circuit function as a DC voltage source, and the DC voltage output by the voltage source is converted into an AC voltage with the desired frequency in the inverter circuit. In the voltage inverter, since the energy is fed back to the capacitor of the DC intermediate circuit and the DC voltage is raised, it is also necessary to install a special discharge circuit for the order picker to prevent the converter device from being damaged due to excessive voltage.
② The current-type inverter of the electric order picker reclaimer is to supply the DC current from the rectifier circuit, and smooth the current through the reactance of the intermediate circuit and then output it. The rectifier circuit and the DC intermediate circuit function as a current source, and the AC current output by the current source is converted into the required AC current in the inverter circuit, distributed to each output phase, and then supplied to the motor as AC current. In the current-type inverter, the control of the motor stator voltage is realized by controlling the current after detecting the voltage. For the current-type inverter, the DC circuit can be turned into an inverter circuit by inverting the voltage of the DC intermediate circuit during the braking process of the motor, and the energy of the load can be fed back to the power supply. Since the energy can be fed back to the power supply when the current control method is adopted, and it is easier to deal with situations such as load short circuit, the current control method is more suitable for the order picker reclaimer.
