DocumentCode :
1810921
Title :
Elimination of the positive zero in fixed frequency boost and flyback converters
Author :
Sable, Dan ; Cho, Bo ; Ridley, Ray
Author_Institution :
Dept. of Electr. Eng., Virginia Polytech. Inst. & State Univ., Blacksburg, VA, USA
fYear :
1990
fDate :
11-16 March 1990
Firstpage :
205
Lastpage :
211
Abstract :
It is shown how a fixed-frequency, leading-edge modulated pulse width modulation can eliminate the undesirable positive zero in practical boost and flyback converters. This allows a substantial improvement in the closed-loop characteristics. Several techniques are employed to predict this result. The design procedure for elimination of the positive zero is presented. Experimental verification is provided. By providing an effective feedforward of the load current, this technique ensures excellent load transient response and low output impedance. There are several advantages to this technique. Measurement of the control-to-output transfer function cannot be easily performed. Also, the positive zero elimination is dependent on the capacitor ESR value. This technique can be susceptible to noise since the output voltage switching ripple is not filtered in the compensation network.<>
Keywords :
closed loop systems; power convertors; pulse width modulation; transients; PWM; closed-loop characteristics; compensation network; fixed frequency boost convertors; flyback converters; load current feedforward; load transient response; output impedance; output voltage switching ripple; positive zero elimination; Capacitors; Frequency; Impedance; Paramagnetic resonance; Performance evaluation; Pulse width modulation; Pulse width modulation converters; Transfer functions; Transient response; Voltage;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Applied Power Electronics Conference and Exposition, 1990. APEC '90, Conference Proceedings 1990., Fifth Annual
Conference_Location :
Los Angeles, CA, USA
Type :
conf
DOI :
10.1109/APEC.1990.66413
Filename :
66413
Link To Document :
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