A New Hybrid Islanding Detection Technique for Microgrid Using Virtual Synchronous Machine

Abstract

Photovoltaic (PV) based system connected to the grid has become more successful in terms of continuous supply and reliability. Before connecting the PV system to the grid there must be security and safety for the PV system. The challenge is to detect the islanding state when the grid is separated from the main network. This chapter discusses the various islanding detection techniques (IDTs). In this work, the active and passive IDT is discussed and compared their results. In the active IDT, there is a supply of disturbance signals to the system and drift in voltage and frequency, and then the islanding state is detected. In the passive IDT, no disturbance signal is present in the system; islanding state is detected based on the comparison of the threshold value and measured value of voltage and frequency. This work offering a new hybrid IDT based on a Virtual Synchronous Machine (VSM) controller, which enables the grid integration of distributed generation (DG) sources. This hybrid IDT has the benefit of being able to be included in the operation of DG inverters without requiring any additional control modifications. The results are verified in the MATLAB Simulink.