Classified by frequency conversion
Ac-ac inverter: also known as direct inverter, the power frequency alternating current is directly converted into frequency and voltage adjustable alternating current supply motor. The conversion efficiency is high, the overload capacity is strong, but the continuous adjustable frequency range is narrow, generally less than 1/2 of the rated frequency, mainly used for low-speed and large-capacity drag systems.
Ac – DC – AC inverter: also known as indirect inverter, the power frequency alternating current through the rectifier circuit into pulsating direct current, and then through the inverter circuit to inverter the direct current into arbitrary frequency, continuous adjustable three-phase AC supply motor. The frequency adjustment range is wide, and it has obvious advantages in improving the characteristics of the motor after the frequency, and is the most widely used frequency converter.
Classified according to the main circuit DC link energy storage mode
Voltage inverter: the main circuit DC link uses large electrolytic capacitors as energy storage components, DC link output DC voltage waveform is relatively flat, the internal resistance of the power supply is small, the output voltage waveform is rectangular wave or stepped wave, the output current waveform is similar to sine wave, commonly used in the occasion of large load voltage change.
Current inverter: The DC link of the main loop uses series inductors as energy storage components, the output DC current waveform is relatively flat, the internal impedance of the power supply is large, the output current waveform is rectangular wave, the output voltage waveform is similar to sine wave, suitable for the occasion of large load current changes and the need for feedback braking and frequent reversible operation of production machinery.
Classified by modulation mode of output voltage
Sine-wave pulse width modulation (PWM) inverter: the amplitude and frequency of the output voltage are controlled at the same time in the inverter circuit, and the output voltage is controlled by changing the duty cycle of the output pulse. High power factor, fast adjustment speed, output voltage and current waveform close to sine wave, suitable for single or multiple motor parallel operation, dynamic performance requirements of high speed regulation system.
Pulse amplitude modulation (PAM) inverter: the “variable voltage” and “frequency conversion” are completed separately, the amplitude of the output voltage is controlled in the rectifier circuit part, and the output frequency is controlled in the inverter circuit part. It is a synchronous speed regulation mode, when the system is running at low speed, the harmonics and noise are larger.
Tel/Fax: 0086-577-62840011
Wechat/WhatsApp: 008615868075256