Design And Research Of High-power AC Drive System For Mine Hoist

Throughout the mines, hoist is charged with the important responsibilities of transporting mineral,material and staff. Hoist is the key to connected the mouth of a well with underground.As a result,enhancing reliability and productivity of the machine has been the focus of attention and research. Traditional hoist uses contactor-relay control mode in general, this control method has some characteristics,such as low-power, low efficiency,simple operation and so on,and at present,it has been phased out. With the development of technology, China's mine production equipment constantly develop toward modern form,intelligent, power-oriented. High power and high efficiency rate become the trend of mines in the future. Drive system is the key of equipment hoist energy transmission and speed adjustment, and their research has been of great significance. Therefore, this paper chosed the high-power AC drive system of hoist to study.Firstly, the status of development of power electronic device development prospects and AC drive systems are introduced. By analyzing the overall structure of the hoist system,determining the role of the drive system in the whole system, analyzing and comparing the three common hoist AC speed mode, in which making a comprehensive comparison of the advantages and disadvantages, finally,the paper choosed a suitable hoist power AC drive system, namely AC- DC- AC inverter system.Secondly, using high-power permanent magnet synchronous motor as a power lifter,AC- DC- AC circuit as a main circuit system, the control section of the main circuit choses direct torque control technology. It is introduced that the working principle of permanent magnet synchronous motor and direct torque control technology. In view of the torque ripple and the switching frequency instability shortcomings in traditional direct torque control systerm, this paper choose space vector pulse width modulation(SVPWM) into the synchronous motor direct torque system. For two-level inverter`s output having alot of voltage harmonics, and it is not suited for high-voltage, high-power situation, this paper introduces a three-level inverter, and joined the SVPWM direct torque control technology and the principle of the technology is analyzed.Thirdly, for mine special voltage levels and poor production environment, the AC- DC-AC voltage source main circuit parameter was selected and designed. The hardware and software were designed for synchronous motor direct torque control system permanent on the basis of TI's DSP chip TMS320F2812. It played a guiding role for further study of thedirect torque drive system of mine hoist system and the construction of permanent magnet synchronous motor.Finally, two simulation model were carried out on MATLAB / SIMULINK software platform.They were the direct torque hoist traditional control technology and based on two-level, three-level inverter SVPWM direct torque control technology respectively. Two simulation system were simulated,and the experiment results show that the two control methods have their own characteristics. In the high- power drive systems, the selection of three-level inverter SVPWM direct torque control technology is more suitable.