In this system, the 110KW main motor of the refiner is driven by the D71 110KW inverter, and the central control system DCS is connected with all the executive components and sensors of the entire production line to monitor the field conditions of each transmission system in real time. The central control system controls the start-stop, frequency setting, fault reset and other commands of all inverters, and simultaneously collects data such as current, voltage, bus voltage, and operating frequency of all inverters to monitor each inverter in real time.