RealizationofSpeedControlforaSeparatelyExcitedDCMotor UsingFuzzyLogic

Abstract

TheDCmotorsareusedasanadjustablespeedmachineforwiderangeofoperation. The four main reasons for the usage of DC motors are reliability, simplicity, ease of application and favorable cost. At the same time, the DC motor drive is less complex compared to AC motor drives. Thus, the use of electric DC motor is increasing steadily. However, it faces efficiency problems on the dynamic response for high speed sensitive applications. This is usually due to the power electronics devices particularly converters and algorithm of inference used. To counteract these drawbacks, four quadrants operation of chopper based speed control of separately excited DC motor using fuzzy logic is introduced in the study. In this thesis, the effect of number of input error membership functions on the speed performance is studied, simulation is performed for both fuzzy and PI controllers using MATLAB/Simulinksoftwareandaccordinglycomparisonismadeontheirspeedperformances. From the results obtained efficiency problems observed during speed control in dynamically changing environment has resolved using fuzzy logic controller and better speed responses are obtained as compared to PI controllers. In addition to this, as the number of error membership functions increases, an improvement on the speed tracking has noticed and hence, reduced steady state error and smooth dynamic response is obtained.