Indirect output voltage regulation of DC–DC buck/boost converter operating in continuous and discontinuous conduction modes using adaptive backstepping approach

Abstract

In this study, an adaptive non-linear controller is designed for DC-DC buck/boost converter which is robust and stable against converter load changes, input voltage variations and parameter uncertainties. The proposed controller is developed based on input-output linearisation using an adaptive backstepping approach. The controller can be applied in both continuous and discontinuous conduction modes (CCM and DCM). Owing to non-minimum phase nature of buck/boost converter, the output voltage of this converter is indirectly controlled by tracking the inductor reference current. The inductor reference current is generated by a conventional PI controller. Using a MATLAB/Simulink toolbox and a stand-alone TMS320F2810 digital signal processor from Texas Instruments, some simulations and practical results are presented to verify the capability and effectiveness of the proposed control approach.

Lyapunov Based Adaptive-Robust Control of the Non-Minimum phase DC-DC Converters Using Input-Output Linearization

“…Finally, experimental response of the designed controller is presented in a wide range of operation, particularly during transition between different modes, in Section IV. As will be shown later, the proposed controller has better dynamic response compared to adaptive the nonlinear approach [16].…”

“…In [16], an adaptive nonlinear approach is developed for closed-loop control of the DC-DC buck/boost converters. The proposed controller in [16] can be applied in both discontinuous and continuous conduction of the inductor current.…”

“…The proposed controller in [16] can be applied in both discontinuous and continuous conduction of the inductor current. However, the controller gain must be adjusted during the transition of the converter between different modes.…”

“…However, the controller gain must be adjusted during the transition of the converter between different modes. In fact, two different controllers are required in a wide range of operations in [16]. Hence, the necessity for controller selection in different modes deteriorates dynamic the response of the system.…”

“…In other words, if any unmolded dynamics exists in the system model, the response of the adaptive controller may be adversely affected. To increase the model accuracy in [16], the effect of the inductor equivalent series resistance is considered during the development of the controller. Considering all parasitic elements (such as the equivalent series resistance of the power switch, diode, and capacitor) in the converter model and their estimation by adaptive controller obviously increase the complexity of the system; hence, its application in the practical regulators will be difficult.…”