Elevator inverter plays what role in the elevator (a)

The main role of the elevator inverter by changing the frequency of alternating current, energy efficiency and speed, and to achieve automatic control and precision control.
The elevator inverter is the use of power semiconductor devices will be the role-off frequency to another frequency power conversion power control devices. Can be divided into AC - AC elevator inverter, AC - DC - AC elevator inverter. AC - AC elevator inverter alternating current into direct are variable frequency and voltage AC; AC - DC - AC elevator inverter is first rectified alternating current into direct current by the rectifier first, and then through the elevator inverter to the DC current and voltage can be changed into a frequency of alternating current.
PWM is the English Pulse Width Modulation (Pulse Width Modulation) acronym, according to certain rules to change the pulse width of the pulse train to adjust the output volume and a tone waveform by value. PAM is the English Pulse Amplitude Modulation (pulse amplitude modulation) acronym is changed according to certain rules pulse amplitude pulse train, to regulate the output value and a modulation waveform.
elevator inverter main circuit can be divided into two categories: voltage is converted to DC voltage source elevator inverter AC and DC circuit filter is a capacitive; Current DC current source is converted to AC elevator inverter, its stone DC circuit filter inductor.
Asynchronous motor torque and the rotor flux of the motor a current flows resulting from the interaction between the rated frequency, if the voltage is fixed and only reduce the frequency, then the magnetic flux will be too large, the magnetic circuit saturation, severe when burning motor. Therefore, the frequency and voltage proportional to a change, that is to change the frequency converter output voltage while controlling the motor to maintain a certain flux, to avoid weakening and magnetic saturation phenomenon. This control method is used for fan and pump energy-saving elevator inverter.