An analysis of the dynamic performance of D.C. machines with thyristor assisted commutation

Abstract

The thesis presents a method of analysis of direct current machines using thyristor assisted commutation. The method is based upon the General Machine Theory and the formulation of voltage and torque equations from the theory is shown to be successful. These equations have predicted the performance of the machine over a wide range of operating conditions. A computer programme has been developed to deal with the most complex operating conditions and, by suitable simplifications, the programme is readily adaptable to compute steady state characteristics. A subsidary theme of the thesis is to show how the output of thyristor assisted machines may be controlled by an electronic method of rocking the brushes. The method is simply demonstrated on no load or light load conditions but loading effects produce some limitations. Sufficient experimental results are given to illustrate the method.