Experimental Analysis of Immersion & Invariance Adaptive Control for an Interleaved DC/DC Boost Converter with Unknown Load Type

The retrofit of the energy system leads to new challenges for the control of power electronic devices. To account for parametric uncertainties of passive elements, or unknown ambient conditions in real-world applications, the use of proportional-integral (PI) controllers in cascaded schemes is common. Observer based adaptive control approaches can be leveraged to accommodate such uncertainties and at the same time provide parameter estimates and enable model based control approaches. From an application perspective, the question arises about the consequences of wrong modelling assumptions, for example regarding the often unknown load type. In this work an interleaved DC/DC boost converter is considered, that supplies a DC-bus to which generally unknown loads can be connected, such as a grid-tied three phase inverter. This paper illustrates the design of an observer based adaptive controller using the Immersion & Invariance framework with an energy shaping plus damping injection passivity based controller. A highly simplified, large signal plant model as well as the assumption of a purely resistive load are used for the design. The provided experimental results show that the adaptive controller is able to cope with violations of the modeling assumptions concerning the load type in a real-world application scenario.