Mine hoists are the main equipment for underground mine transportation. It transports ore, waste rock, lifting personnel, materials, equipment and other transportation links along the wellbore with certain equipment. Mine hoisting equipment can be divided into shaft hoisting equipment and inclined shaft hoisting equipment according to the inclination angle of the wellbore; according to the lifting container, it can be divided into cage hoist and bucket hoist, etc.; according to the application, it can be divided into main hoist (special or main promotion) Ore, commonly referred to as main shaft hoist), auxiliary shaft hoist (lifting waste rock, lifting personnel, transporting materials and equipment, etc., generally referred to as auxiliary shaft hoist) and auxiliary hoist (such as patio elevator, overhaul, etc.) . Stainless Steel Printing Wire Mesh Stainless Steel Printing Wire Mesh,Stainless Steel Printing Screen,Stainless Steel Printing Mesh,Stainless Steel Wire Screen Printing Mesh SHENZHOU SHUANGYOU MESH CO.,LTD. , https://www.firstwiremesh.com
Mine lifting is the throat of underground mine production. Therefore, no matter which kind of hoist, the requirements for electric drive are very high. Because the performance of electric drive system is good or bad, the reliability is directly related to the efficiency of mine production and mine. Production is proceeding normally. The requirements for the electric drive system of the mine hoist are: good speed regulation performance, high speed regulation accuracy, four-quadrant operation, fast forward and reverse running, fast dynamic response, accurate braking and positioning functions, High reliability requirements.
At present, the electric drive system of mine hoist in China's underground mines mainly includes: for large-scale mine hoists, mainly adopting DC drive system, using DC motor-DC generator system and thyristor converter-DC motor system; these two systems There are inherent disadvantages of DC motors, such as low efficiency and large maintenance workload. For medium and small hoists, AC electric drive systems are often used, such as AC winding motor, motor rotor switching resistance speed control. Although the electric drive system is simple, it is stepped speed regulation. Poor performance, low efficiency, a large amount of electrical energy is consumed in the rotor resistance of the motor, and the reliability is also poor.
The application of variable frequency speed control technology to mine hoist is the development direction of mine hoist electric drive system. China has several large-scale mine hoists using AC-AC variable frequency speed control system, which has achieved good results, but its shortcomings are low power factor, large harmonics, harmonics and power factor compensation devices. With the development of frequency control technology, AC-DC-AC voltage frequency control technology has begun to be applied in mine hoists. For example, foreign mines have applied active front-end three-level inverters to mine hoists. According to the introduction, the AC hoist adopting such variable frequency speed regulation can overcome the shortcomings of DC speed control system and AC-AC frequency control system. It is the development direction of hoist electric drive. For example small AC hoist has been successfully applied inverter, such as inverter Electronics Co., Ltd. and Shandong Dongying City scenery developed in cooperation with the East and Crafts Co., Ltd., successfully applied to 380V Shandong Ningyang County Huaning coal mine, 180kw The exchange is on the hoist.