The Research And Design Of Reversible Digital Field Regulator Using DSP

With the development of micro-electronic technology, the operation of digital processor becomes more quick and powerful, and its price is cheaper. In the design of control system, more and more designers prefer to select digital control strategy with advantages of flexible control, powerful functions and high precision, compared to analogue control. Digital controller is used widely in industrial application. However, analogue controller is dominant in electric propulsion system for underwater ship. Therefore, it is a task of top priority to develop digital controller substituted for analogue controller as early as possible.This paper presents reversible digital field regulator with DSP and IGBT, which is substituted for current analogue field regulator with thyristors as power element. By powerful operation capacity and external settings of DSP, digital control algorithm is realized and electric circuit is simplified. Meanwhile, fully-controlled IGBT enables reversible flow of field current and reduce in the size of filter elements of main loop, so that the complete of device becomes smaller and lighter.Beginning with mathematic modeling of control object, the paper gives the design of regulators in current loop and speed loop of the system by introducing typical system design method. After that, how to configure hardware circuit of the system with DSP and IGBT is discussed, and each functional module of hardware circuit is introduced. Software structure of the system is analyzed, functions of every module in software system are explained, and flow diagram of sub-programs is given. Finally, experimental results of the system are given.ft is shown from test results that, by using DSP for digital control of field system, hardware circuit is simple and programming is easy. In addition, by using IGBT in main loop of the system, control and operation of power elements is easy and reliable, and reversible flow of field current can be realized. Test shows that control strategy is practicable and effective, and operation of the system is reliable.