Abstract: This paper introduces the transformation of a mine hoist system using a frequency converter to achieve safe production, reduce energy consumption, and improve production efficiency. Keywords: mine hoist, frequency conversion speed regulation system, energy recovery 1 Introduction AC-DC-AC frequency conversion speed regulation system is widely used in many fields, but rarely in mine hoists. At present, most mine hoists still use the traditional method of speed regulation by connecting the rotor of a wound asynchronous motor with series resistance. This system belongs to stepped speed regulation, with small low-speed torque, large starting current and shifting current impact, low energy utilization, and high operation difficulty in the starting and stopping stages. After long-term use, the failure rate is high. However, using a frequency converter speed regulation can overcome the above disadvantages, and the technology is mature and reliable. As long as the appropriate frequency converter is selected according to the characteristics of the hoist load, the requirements can be met. 2 Advantages of using this system (1) Stepless speed regulation is achieved, and the impact current during starting and acceleration shifting is very small, which reduces mechanical impact, makes the operation more stable and reliable, and effectively reduces the occurrence of failures. (2) It has complete safety protection functions. In addition to general overvoltage, undervoltage, overload, short circuit, and temperature rise protection, it also has many functions such as interlock protection and automatic speed limit protection. (3) It has multiple braking methods such as DC braking, energy consumption braking, and regenerative braking, which improves the reliability of operation. (4) The system operates in four quadrants, and the regenerative energy is directly fed back to the power grid, which is more energy-efficient. (5) It simplifies the operation of workers during the start-up and shutdown stages, and the operating speed is good, saving a lot of electrical energy. [b][align=center]For details, please click: Modification and Application of Variable Frequency Speed ​​Control System for Mine Hoists[/align][/b]