The output voltage regulation problem of a DC-DC buck converter is investigated in this paper via an observer-based finite-time output-feedback control approach. Considering the effects of unknown load variations and the case without current sensor, by using the technique of adding a power integrator and the idea of nonseparation principle, a finite-time voltage regulation control algorithm via dynamic output feedback is designed. The main feature of the designed observer and controller does not need any load's information. Theoretically, it is proven that the output voltage can reach the desired voltage in a finite time under the proposed controller. The effectiveness of the proposed control method is illustrated by numerical simulations and experimental results. KEYWORDS DC-DC buck converter, finite-time control, observer, output-feedback control
INTRODUCTIONAs a kind of important power electronic devices, the main function of DC-DC converters is used to achieve energy conversion, which are widely applied in many industrial occasions, such as switching power supply, direct current motor drives, and communication equipment. 1 With the development of distributed power generations, it is required that the DC-DC converter has high-quality, reliable, efficient power supplies and other features. 2,3 However, from the control viewpoint, how to improve the control system performance for DC-DC converter is challenging since DC-DC converters are usually time-varying systems due to their switching operation. 4 In the past years, some nonlinear control strategies have been proposed to achieve performance improvement of DC-DC converter systems, such as backstepping control approach, 5 passivity control approach, 6,7 sliding-mode control approach, 1,8,9 and robust control approach. 10 Recently, the finite-time control method (a newly developed nonlinear control method) was employed to design control system for DC-DC converter systems. 11,12 The main advantage of the 5274
