ANALYSIS OF FRONT-END CONVERTER WITH UNITY POWER FACTOR AND LOW INPUT CURRENT THD FOR TRACTION APPLICATION

Abstract

The work presented in this thesis deals with the simulation, design & development of the front-end converter. Here
front-end converter is AC/DC or DC/AC converter at the front end of the system. A suitable PWM technique is employed in order
to obtain the required output voltage in the line side of the inverter. SPWM technique has been used for providing triggering
pulse to the FEC and Inverter both in which IGBT is used as switch. It is very accurate method as it is concern with the
modulation of the amplitude and frequency. By changing Modulation index (ma) amplitude of the output voltage and current can
be controlled. The main advantage of this approach is that the total harmonic distortion (THD) in line and phase voltage
decrease as the value of the modulation index increased. The value of fundamental component in line and phase voltage is
increased with the increase in modulation index. PWM is one of the best methods for the controlling the output voltage especially
SPWM because it make it possible to control frequency and magnitude both in traction Induction motor. It is also used for the
reduction of the harmonics from the system. FEC has advantage of drawing balanced supply even in the unbalance supply form
Utility. Using Matlab simulink this operation will be shown with the details like THD analysis, output voltage, output current,
triggering signals for switching. Total circuitry controlling will also be developed in the Matlab. The FEC prototype hardware
results are nearly same as simulation results.