Comparative Analysis of Modulation Techniques in Frequency Converter

A generalized frequency converter has been realized which makes use of a cyclo-converter in newer form AC-AC converter. An attempt has been made to operate this converter both in a conventional low frequency AC-AC converter and a new high frequency AC-AC converter. The ability to directly affect the frequency conversion of power without any intermediate stage involving DC power is a huge advantage of the system. The output of this converter has a frequency either f(o) = f(i) x N-r or f(o) = f(i) / Nr where N-r is an integer and fi is the source frequency. A methodology is developed to generate the required trigger signal for any integer multiple/sub multiple of the output frequency. The undesirable harmonic components in the output of the frequency converter have been minimized using four modulation techniques namely; sinusoidal pulse width modulation (SPWM), delta modulation (DM), trapezoidal modulation (TM) and space vector modulation (SVM) technique. The converter is simulated using well known software package MATLAB. Comparative simulation analysis is presented for a single phase frequency converter (SPFC) topology with all these modulation techniques when the converter is operating both step up as well as for step down mode.