Improved Sensor FDI using AC ripple signals analysis of the d-axis component of the line current

Satisfactory operation performance of electrical systems depends heavily on different factors, namely sensors accuracy and system components. This paper presents easy fault detection, isolation method against currents measurement failure for grid connected photovoltaic system, were DC offset, and scaling errors are considered. This method does not need any extra hardware. It is based on analytical analysis of d-axis components of line current at the grid angular frequency ωg and 2ωg. These components are extracted through band pass filters in order to generate two residuals, which are employed for fault detection and isolation. Simulation results present the effectiveness of the proposed technique. An experimental platform was carried out to validate the obtained simulations results.

I. Introduction

In the last few years, renewable energy source has significantly increased because the remarkable diminution of the conventional energy (such as nuclear sources, gas, coal, fossil fuels, etc.). In this context, Photovoltaic (PV) systems present a very large interest in order to avoid several environmental problems. These systems are usually functioned in a stand alone mode and in grid connected of operations. The inner present several advanced structures and topologies in order to reach the high performance [1]. These structures are focused on the power converters, which are used to operate as an inverter (DC-AC converter) and/or a DC-DC converter. different control strategies are investigated in order to boost the power quality transferred to the grid.