Research On Speed Control Curve Of The High Power Motor Stepless Speed Concol System With The Combination Of Mechanics And Electronics

With the development of China’s industrial economy, speed control system of high power motor has been widely used in China’s major industries. It leads to speed control system of high power motor in the long-term transition process with large energy loss and serious motor heating to changing speed frequently. The speed control curve of the motor is directly related to the power consumption in the transition process. But it is discussed how to choose the driving ways of motors, ignoring the influence of speed control curves in the previous studies of domestic and foreign scholars. Therefore, the high power motor stepless speed control system with the combination of mechanics and electronics is taken as the research object in this thesis. Aiming at the transition process of the system, five kinds of speed control curves and the principle of selecting speed control curve is proposed, and more energy-saving speed control curve family and the best speed control curve to save energy for the system in the constant torque load and quadratic rate load are elected in this thesis.First of all, basic principle, structures, working process and the advantage compared to others of the high power motor stepless speed control system with the combination of mechanics and electronics are introduced. Influencing factors of the system’s power consumption in the speed regulating process are analyzed by theoretical derivation, and everyone is discussed.Secondly, based on theoretical derivation, according to the relationship between rotational speed and angular acceleration, five kinds of speed control curves are proposed. According to the characteristics of each speed control curve family, the typical speed control curve of each curve group is given.Thirdly, with the Baosteel’s coke-oven gas fan as the engineering background and the minimal inertia as design principle, a high power motor stepless speed control system with the combination of mechanics and electronics is designed. Based on the kinematics model and the dynamic model of transmission system, the simulation models of the high power motor stepless speed control system with the combination of mechanics and electronics in the constant torque load and quadratic rate load are proposed are built via the software Simulink, the speeds of which can be controlled.Finally, based on the simulation results, it is proved that the third curve, in which the acceleration is big in low speed segment and the acceleration is small in high speed segment, is the most energy-saving one in the constant torque load and quadratic rate load, and the reasons are found. On the basis of this, the best speed control curve for energy saving effect is selected.