Higher Order Sliding Mode Observer-Based Sensor Fault Detection in DC Microgrid’s Buck Converter

Daijiry Narzary,Kalyana C Veluvolu

doi:10.3390/en14061586

Abstract

Fault detection in a Direct Current (DC) microgrid with multiple interconnections of distributed generation units (DGUs) is an interesting topic of research. The occurrence of any sensor fault in the DC microgrid should be detected immediately by the fault detection network to achieve an overall stable performance of the system. This work focuses on sensor fault diagnosis of voltage and current sensors in interconnected DGUs of the microgrid. Two separate higher order sliding mode observers (HOSM) based on model dynamics are designed to estimate the voltage and current and generate the residuals for detecting the faulty sensors in DGUs. Multiplicative single and multiple sensor faults are considered in voltage and current sensors. By appropriate selection of threshold, single and multiple sensor fault detection strategies are formulated. A hierarchical controller is designed to ensure equal sharing of current among the DGUs of the DC microgrid and stabilize the system. Simulations are performed to validate the proposed approach for various configurations of the DC microgrid under various load and off noise conditions.

Highlights

The increase of energy demand and the concern about the climate change has led to extensive research for renewable energy sources (RES)
The proposed method is analyzed with different sensor fault conditions and the results show that the proposed approach is successful in identification of single and multiple sensor faults in the interconnected Direct Current (DC) microgrid system
A sensor fault detection scheme is developed for interconnected distribution generation units (DGUs) of a DC microgrid

Summary

Introduction

The increase of energy demand and the concern about the climate change has led to extensive research for renewable energy sources (RES). Microgrids are used to integrate different RES and electrify the remote areas continuously. A microgrid is a small scale power system that consists of loads, distribution generation units (DGUs) and other units for storage which is interconnected with power lines of the grid [1]. In a DC microgrid, a Buck converter contributes an important role for the efficient performance of the DC microgrid. The main advantage of using DC microgrid over AC microgrid is that it can be operated in grid connected or in islanded mode. DC microgrids [2,3,4]

Objectives

Results

Discussion

Conclusion