Abstract: This paper mainly introduces the problems existing in the frequency control system for the main drive motor of the No. 1 265 m sintering machine in the Sintering Plant of Yinshan Section Steel Company, the corresponding transformation programs, and the transformation results. Key Words: sintering machine, frequency converter, macro-arrangement, damping brake 1 Introduction In the main drive electrical control system of the No. 1 265 m sintering machine in the new area of ​​the sintering plant, the motor model is YZPBF-160L-437kW, the speed is 1980r/min, and the control system adopts frequency converter control. The original design was that when the instantaneous current of the motor is too high or the frequency reaches the set point, the motor brake would be activated to hold the motor. At this time, the frequency converter continues to operate while the motor continues to run, causing a rapid increase in the motor's operating current. This triggers the frequency converter's protection mechanism or the air switch to trip, thereby reducing the sintering machine's operating rate and affecting sinter production. Furthermore, when maintenance or replacement of the trolley or a malfunction in the automatic position requires manual operation, the original design cannot properly adjust the sintering machine speed manually, significantly impacting maintenance and production. 2. Main Problems The original design used a Schneider ATV58 45kW/60HP 380/500V frequency converter for control. The basic connection circuit diagram of the frequency converter is shown in Figure 1. [b][align=center]For details, please click: Sintering Machine Main Drive Motor Frequency Conversion Control System Retrofit[/align][/b]