Sensor Fault Detection for Line Regulating Converters supplying Constant Power Loads in DC Microgrids

The objective of this paper is to increase the reliability of DC-DC converters operation, used in DC Microgrids (MG). This paper will determine the design requirements for a Sensor Fault Diagnosis (SFD) strategy for a DC-DC converter intended for DC MG, in order to allow continuous operation during erroneous sensor measurements. The SFD scheme is based on residuals generated by a generalized observer scheme. The observer gains is based on adaptive high-gain observer theory. The generated residuals are compared with thresholds, to detect sensor faults. The SFD scheme for the Line Regulating Converter (LRC) side is validated through simulations on a prototype DC MG system where the sensors are subjected to three types of sensor faults. In this paper, the prototype DC MG system will consist of a battery which is connected to the DC bus through a bidirectional buck/boost converter. A buck converter is used as LRC connected to the DC bus.