Introduction: The inverter is mainly composed of rectification (AC to DC), filtering, inversion (DC to AC), braking unit, drive unit, detection unit, microprocessor unit, etc. The inverter adjusts the voltage and frequency of the output power supply by the internal IGBT opening and closing, and provides the required power supply voltage according to the actual needs of the motor, thereby to achieve the purpose of energy saving and speed adjustment. In addition, the inverter owns many protection functions, such as over-current, over-voltage, overload protection, etc. With the continuous improvement of industrial automation, inverters have also been widely used.