Abstract : Addressing some shortcomings of the traditional master-slave control method of frequency converters in dual-machine coaxial systems, this paper proposes an alternative non-master-slave control method for dual-machine coaxial systems. This control method can quickly and conveniently achieve dynamic load balancing, improve the transient quality of the feeding system, and utilize the internal brake function of the frequency converter to achieve zero-speed direct torque control of the load, making the timing of the opening/closing of the blast furnace charging car brake system and the start/stop of the frequency converter more convenient. Keywords : Frequency converter, dynamic load balancing, brake 1 Introduction Blast furnace feeding systems in ironmaking plants have two methods: belt conveyor feeding and charging car feeding. Charging car feeding is widely used due to its smaller footprint. During charging car feeding, the main winch of the charging car is the key equipment of the feeding system. Considering factors such as feeding speed and equipment backup requirements, a single-drum, dual-motor, dual-charging-car winch system is currently commonly used. From a transmission perspective, this dual-motor winch system, in addition to having large inertia and large starting torque, also needs to meet the requirements of load balancing and multi-speed operation of the two motors. Previously, multi-speed motors or DC speed control drive systems were commonly used, but both systems have significant drawbacks. Multi-speed motors have high starting currents, causing significant impact on the power grid, motor, and mechanical equipment; their speed is stepped; and they require free stopping, which cannot be manually controlled. DC drive systems can achieve soft starting, soft stopping, and stepless speed regulation, but DC motors require regular maintenance, resulting in high maintenance costs. Using a variable frequency speed control (VFD) scheme for the hoist can overcome these shortcomings. VFDs not only achieve soft starting, soft stopping, and stepless speed regulation, but their associated AC squirrel-cage motors are also maintenance-free. Therefore, with the continuous improvement of VFD performance and the continuous decrease in price, this solution has been increasingly adopted. This article details the application of VFDs in the blast furnace main hoist system. [b][align=center]For details, please click: Blast Furnace Charge Car Main Hoist VFD Control System[/align][/b]