Abstract : Mine hoists are crucial equipment in coal mine production. Their safe and reliable operation directly impacts a company's production status and economic benefits. Keywords : Mine hoist, improvement 1. Overview of Commonly Used Hoists Mine hoists are crucial equipment in coal mine production. Their safe and reliable operation directly impacts a company's production status and economic benefits. In general, coal is mined underground, and the mined coal is transported to the surface via a hoist through an inclined shaft. The coal car is similar to a freight car on a train, only smaller in height and volume. A winch hoist is located at the shaft entrance. A motor drives a drum to rotate via a reducer. A steel wire rope is wound several times on the drum, with a train of coal cars attached to each end. Driven by the motor, a train full of coal is pulled up from the inclined shaft. Simultaneously, an empty train is lowered down the inclined shaft, balancing the load. At any given time, a loaded train is always moving upwards, preventing empty travel. The motor is always in an electric state. This drive system requires frequent forward and reverse starting, deceleration, and braking of the motor. Furthermore, the motor speed changes in a fixed pattern. The power of the inclined shaft hoist is provided by a wound-rotor motor, using rotor resistance speed regulation . 2. Disadvantages of the hoist system Currently, most medium and small mines use inclined shaft winches for hoisting. Traditional inclined shaft hoists generally use AC wound-rotor motor resistance speed regulation systems. The switching of the resistor is controlled by relays and AC contactors. Due to the frequent operation of the AC contactors during speed regulation and the long operating time of the equipment, the main contacts of the AC contactors are prone to oxidation, leading to equipment failure. In addition, the speed control performance of the hoist during deceleration and crawling phases is poor, often resulting in inaccurate stopping positions and frequent starting, speed regulation, and braking of the hoist. A considerable amount of power is generated in the resistor connected in series in the rotor's external circuit. This AC wound-rotor motor resistance speed regulation system is a stepped speed regulation system with poor smoothness. At low speeds, the mechanical characteristics are relatively soft, the static error rate is large, the slip power consumed in the resistor is large, the energy saving is poor, the current surge during starting and speed regulation is large, the vibration is large during medium and high speed operation, and the safety is poor. [b][align=center]For details, please click: A Brief Discussion on the Application of Frequency Converters in Mine Hoist Retrofitting[/align][/b]