Title :
H∞ control applied to boost power converters
Author :
Naim, Rami ; Weiss, George ; Ben-Yaakov, Shmuel
Author_Institution :
Hardware Dept., Telrad Ltd., Lod, Israel
fDate :
7/1/1997 12:00:00 AM
Abstract :
The controller in a pulse-width-modulation (PWM) power converter has to stabilize the system and guarantee an almost constant output voltage in spite of the perturbations in the input voltage and output load over as large a bandwidth as possible. Boost and flyback power converters have a right-half-plane zero (RHPZ) in their transfer function from the duty cycle to the output voltage, which makes it difficult to achieve the aforementioned goals. Here, the authors propose to design a controller using H∞ control theory, via the solution of two algebraic Riccati equations. The almost optimal H∞ controller is of the same order as the converter and has a relatively low DC gain. The closed-loop characteristics of a typical low-power boost power converter with four different control schemes were compared by computer simulation. The H∞ control was found to be superior in a wide frequency range, while being outperformed by the others at extremely low frequencies. Good agreement was found between simulation results and experimental measurements
Keywords :
DC-DC power convertors; H∞ control; PWM power convertors; Riccati equations; closed loop systems; control system analysis computing; control system synthesis; electric current control; transfer functions; voltage control; H∞ control scheme; PWM power converter; algebraic Riccati equations; boost power converters; closed-loop characteristics; computer simulation; control design; control simulation; current regulation; duty cycle; frequency range; right-half-plane zero; transfer function; voltage regulation; Bandwidth; Control systems; Control theory; Frequency; Optimal control; Pulse width modulation; Pulse width modulation converters; Riccati equations; Transfer functions; Voltage control;
Journal_Title :
Power Electronics, IEEE Transactions on