The main circuit of the inverter is to provide the power conversion part of the regulated frequency modulation power supply to the asynchronous motor. The main circuit of the Fuji inverter can be divided into two types: the voltage type is the inverter which converts the DC voltage of the voltage source into the AC frequency converter, the DC circuit Filter is a capacitor. Current type is the current source of the DC into AC inverter, the DC loop filter is the inductance. It consists of three parts, the frequency power supply into DC power "rectifier" to absorb the voltage ripple in the converter and inverter "smooth circuit", and the DC power into AC power "reverse Variable ".
In the rectifier rectifier DC voltage, with 6 times the power supply pulsating voltage, in addition to the inverter pulse current also makes the DC voltage changes. In order to suppress the voltage fluctuation, the inductor and the capacitor are used to absorb the ripple voltage (current). When the device capacity is small, if the power supply and the main circuit constitute the device margin, you can save the inductance using a simple smoothing circuit. In contrast to the rectifier, the inverter is the AC power that converts the DC power to the desired frequency.