Freewheeling mode in bifilar converter for SRG operation

This paper presents an extra freewheeling mode in bifilar Switched Reluctance Generators (SRG) to enhance the Energy Conversion Ratio (ECR). Freewheeling possibility is accomplished through some modifications in conventional structure of bifilar converters requiring only one more MOSFET and diode for each phase. The proposed BiFilar with FreeWheeling (BFFW) mode converter lets the machine increase its phase current after magnetizing period as a result of back-EMF produced by rotor rotation. Using the proposed converter which provides the chance to magnetize at low and demagnetize at high inductances and adding a freewheeling mode bring about several advantages including: higher ECR, more output power and lower ripple in excitation source current. Through MATLAB/Simulink simulation results of a 6/4 bifilar SRG, the improved characteristics of the proposed converter comparing to other conventional converters such as Asymmetric Bridge (AB) and BiFilar (BF) converters are demonstrated.