Key Technology Research Of High Power Three-level Double-fed Adjustable Speed Mine Hoist

According to the needs of "energy-saving and emission-reduction" in our country, the replacement of a number of equipments which drive mine hoists in a inefficient, high energy consumption way is imperative. In the medium-voltage high power field, three-level topology gains many advantages. So the back-to-back converters with three-level topology attracts more and more attentions and have used in many fields.In this thesis, dual three-level double-fed induction motor with stator flux oriented vector control system is studied. Based on the reference voltage decomposition three-level SVPWM algorithm, the neutral-point potential balancing problem is analyzed in detail, and the three-level PWM rectifier using novel virtual flux observer is proposed, the dynamic performance of the direct current control and direct power control strategies are compared. To get an over-all speed range double-fed induction motor control, an observer of the initial rotor angle in stationary state is introduced. In order to gain a good performance in nonlinear-load-condition state, a single neuron adaptive controller is presented to take place of the traditional PI controller.