Research On Disturbance Rejection Control Methods For DC-DC Boost Converter

Over the past decades,DC-DC converters have been widely used in a wide variety of applications,including photovoltaic energy system,wind energy system,hybrid electric vehicles(HEV)and portable electronic products,etc.In modrn control industrial applications,the DC-DC boost converter is widely used due to its low cost,simple structure and high power efficiency.In engineering systems,there exist different kinds of disturbances,such as variations of the load and changes of input voltage and so on.Besides step disturbance,there may also have polynomial form and other forms disturbances.The existence of perturbation has a great influence on the control performance of the system.With the development of modern science and technology,the requirement of precision is becoming higher and higher,and the traditional PID control can not control the high precision under the interference.In order to improve the anti-jamming capability of DC-DC boost converter system,several effective control methods are proposed in this paper.First of all,the state average model is deduced based on the working principle of DC-DC boost converter.Then the non-minimum phase characteristics of the DC-DC boost converter are analyzed.The sliding mode control method based on the current feedback is designed by re-selecting the output variables of the system.Based on this,considering the resistance load disturbance,an improved sliding mode control method based on extended state observer is proposed.Then,considering the resistance load disturbance and input voltage fluctuation at the same time,a PD control method based on disturbance observer is designed.The two lumped disturbances in the DC-DC boost converter state-averaged model are estimated by two disturbance observers respectively.Then,the PD controller is designed based on the precise feedback linearization model,and the virtual control variables are converted to a real of the control.Finally,a new sliding mode controller based on disturbance observation is designed to analysis the mismatched disturbances existing in the DC-DC boost converter system.By adding the estimated value of mismatched disturbance,it can effectively avoid the effect of mismatched disturbance.Compared the ESO with GPI observers,the new sliding mode controller based on ESO and the new sliding mode controller based on GPIO have considerable dynamic effects,accuracy and anti-jamming performance for step disturbances.However,for polynomial-type disturbances,the new sliding mode controller based on GPIO shows better anti-jamming performance and robustness.Numerical simulation and experimental results verify the effectiveness of all control methods.