Experimental Testing of The Wavelet Modulation Technique for 3φ, 5-Level, PECs

This paper presents the implementation and experimental testing of the wavelet-modulation technique for three-phase (3φ) 5 level (5L) power electronic converters (PECs). This version of the wavelet modulation technique is structured as a multi-resolution analysis that can support a redundant non-uniform recurrent sampling-reconstruction of three reference-modulating signals. The reconstruction of reference-modulating signals is achieved by sets of resolution-segmented scale-base linearly combined synthesis wavelet basis functions, which are used as switching signals to activate the switching elements of a 3φ, 5L, VS dc-ac PEC. The presented wavelet-modulation technique is implemented in realtime using a digital signal processing board. Switching pulses generated by the extended wavelet modulation technique are used to operate 3φ, 5L, VS, diode-clamped and flying-capacitor dc-ac PECs. Experimental performance of the tested 5L dc-ac PECs is evaluated, when operated by the presented wavelet modulation, level-shifted pulse width modulation (PWM), phase shifted PWM, and space vector modulation techniques. Experimental tests are conducted for linear, dynamic, and nonlinear loads fed by the tested 5L PECs. Test results show that magnitudes of output voltage fundamental components can be significantly increased, and harmonic distortions can be effectively reduced using the wavelet modulation technique. These features are further demonstrated by performance comparisons with other techniques under similar operating conditions.