The design of the paper is to adjust speed by the simulation methods. In recent years there are power electronic devices and motor model to be used to build power circuit and electric drive control system simulation .The design of the power electronics and electronic drive control system simulation under condition of the MATLAB/SIMULINK. i.e. the power system module to SIMULINK, which provide a new way to make complex power electronic circuits systems analysis, design more easily and effectively, and learn an important method of power electronic circuits and systems analysis. DC adjusting speed system to improve the static and dynamic performance, usually use close-loop control system (including single-loop close-loop and multi-closed-loop system) according to feedback theory, feedback can be divided into different kinds of speed feedback, such as speed feedback current feedback and voltage The closed –loop DC adjust speed system is realized by frequency domain method and DC adjusting speed system diagram. Parameter calculation methods and results are given by MATLAB/SIMULINK .Parameters are adjusted and gain good performance .Results of simulation show that using both frequency domain method and simulation .DC adjusting speed system closed-loop speed make the system a good dynamic performance and effectiveness , so that design of DC adjusting speed system is more simple economic and convenient .
Key word: current deadline,adjusting speed system,MATLAB