WSEAS Transactions on Circuits and Systems
Print ISSN: 1109-2734, E-ISSN: 2224-266X
Volume 13, 2014
Transient Modeling of Z-Source Chopper with and without ESR Used for Control of Capacitor Voltage
Authors: ,
Abstract: The newly proposed Z-source chopper with two controlled switches is used to stabilize the duty cycle above 0.5 is presented. The device has boost capability without polarity reversal in the range of duty cycle 0 to 0.5 and buck-boost capability with polarity reversal of output voltage in the range of duty cycle 0.5 to 1. The above capabilities of the topology are studied through simulation. This paper also presents transient modeling of the proposed Z-source chopper with and without ESR (equivalent series resistance). The effects of ESR are studied in depth and based upon the transient modeling; the dc-link voltage is controlled by direct measurement of capacitor voltage and inductor current. The presence of RHP (right-half-plane) zero in developed average control-to-output model reveal that the output decreases initially before rising toward its new steady-state value when a step increase in control input is applied. The non-minimum-phase transient response can be reduced by proper feed-back control technique. Compensator for both voltage mode and current mode control are designed using classical control technique through small-signal-analysis. Hysteresis band modulator is used for finding out the switching function of switches. Performance of control method of the compensated Z-source chopper is verified by simulation.
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Keywords: Z-source chopper, Current mode control (CMC), Hysteresis band modulator, Buck-Boost capabilities, Non–minimum–phase transient response, ESR (Equivalent series resistance), RHP (Right-halfplane)
Pages: 175-187
WSEAS Transactions on Circuits and Systems, ISSN / E-ISSN: 1109-2734 / 2224-266X, Volume 13, 2014, Art. #18