变频器工作原理： How the converter works: 主电路是给异步电动机提供调压调频电源的电力变换部分，变频器的主电路大体上可分为两类：电压型是将电压源的直流变换为交流的变频器，直流回路的滤波是电容。电流型是将电流源的直流变换为交流的变频器，其直流回路滤波是电感。 它由三部分构成，将工频电源变换为直流功率的“整流器”，吸收在变流器和逆变器产生的电压脉动的“平波回路”，以及将直流功率变换为交流功率的“逆变器”。 Main circuit is to provide the asynchronous motor frequency modulation voltage regulator power supply power transformation of the main circuit of frequency converter in general can be divided into two categories: voltage type is the dc voltage source transformation for ac frequency converter, dc loop filter is capacitance. The current type is the converter for alternating current source dc to ac, and its dc loop filter is inductance. It consists of three parts, the power frequency power transformation for the rectifier, dc power absorption in the converter and inverter voltage pulsation "flat wave circuit", and transform dc power to ac power inverter.