Research And Development Of Digital Direct Torque Control System Based On DSP

In the field of AC machines control, a strategy called variable frequency control is mostly used. As a high performance and new machines control strategy developed in 1980's, direct torque control solves the problems that computation in vector transformation control is complex, the control characters are easily affected by the changes in machines parameters, real results of the experiments can't achieve the level of the theoretical analysis. In this paper, considered the developing actuality that more theoretical research but less systematic realization lies in the field of direct torque control system, we put the emphasis on the basic realization, and design a set of integrate system including software and hardware, which can realize direct control theory.Firstly, according to the mathematical model of asynchronous machines and the principle of variable frequency control, from simple to complication, we debug the part of the hardwired connection by means of SPWM method easily realized. Secondly, according to the traditional theory of DTC, we analyze the approximate round flux theory of DTC in the experiment. Using method of voltage vector selection, we can select the proper voltage vector by the position and magnitude of stator flux as well as the magnitude of torque.Because direct torque control requires very high performance of Real-time, the popular microcomputer core DSP is used as controller in the design of hardware. Its high speed of running is suitable for the experiment. In the main circuit, there is a highly integrated power element: IPM as inverter, which includes seven IGBT, has high switch frequency and fault diagnosis function. IPM greatly decreases the bulk of system...