Title: HIL implementation of an islanding detection and an automatic mode switching for droop-based microgrid
Authors: Shreeram V. Kulkarni; Dattatraya N. Gaonkar
Addresses: Department of Electrical and Electronics Engineering, National Institute of Technology Karnataka, Surathkal Mangalore-575025, Karnataka, India ' Department of Electrical and Electronics Engineering, National Institute of Technology Karnataka, Surathkal Mangalore-575025, Karnataka, India
Abstract: This paper presents the control schemes and performance study of parallel connected inverter based distributed generation sources (DGs) in microgrid for grid-connected and stand-alone modes of operation. This standalone mode of operation of inverter based DG system is mainly based on droop control scheme with the virtual complex impedance in the outer voltage loop. The microgrid load power is proportionally shared by the DGs according to their power ratings which features a good reliability and efficiency. Both the modes are switched automatically based on the Phase Locked Loop (PLL) phase error sin(γ - θ). This phase error is used to detect the islanding during disturbances in the system and also helps in seamless transfer between the modes. The PLL phase error response, islanding detection and mode switching are presented for various fault conditions. The hardware-in-the-loop (HIL) based platform is used to evaluate the performance of the microgrid in both the modes with islanding detection and automatic mode switching operation.
Keywords: microgrid; inverter parallel operation; droop control; phase locked loop; islanding detection; automatic mode switching; hardware in the loop.
International Journal of Power Electronics, 2022 Vol.15 No.1, pp.37 - 54
Received: 07 Feb 2019
Accepted: 16 Aug 2019
Published online: 21 Dec 2021 *