A Directional Protection for an AC Microgrid Consisting of DGs with and without Power Electronic Converters

Mohammadreza mohammadiyan Asiabar¹ Farzad golshan² hamed nafisi³

1) Student of Electrical Power, Karaj Branch, Islamic Azad University, Karaj Branch, Iran
2) Assistant Professor, Department of Electrical Engineering, Islamic Azad University, Karaj Branch, Iran
3) Assistant Professor, Department of Electrical Engineering, Amir Kabir University of Technology, Iran Email:

IOI Code : XCZE-EDZKK
Publication : 3.rd International Congress of Science, Engineering and Technology - Hamburg(germanconf.com)
Abstract :
    In this study, it was proposed protection by a directional element in the micro-grid and considering the purpose of negative sequence impedance size and angle to detect asymmetric error direction and size with current and torque angle of positive sequence impedance for symmetric errors as well as from scattered output sources connected with Power electronic converter was exploited. Some unknown issues were addressed for overcurrent directional relays in microcontrollers with units with power electronics and without power electronics. The directional element suffers from the negative impact of compensating for the leading voltage of the grid voltage in the single control system without a power electronic converter. The proposed orientation element was determined to eliminate the indistinguishability in distances relay and to differentiate forward and reverse asymmetric errors. In this study, a solar cell with a maximum power point detector is also considered as an example of a micro-grid. The simulation results in both scenarios showed that the proposed method performs well for different types of errors based on the use of a solar cell with maximum power point detector as a power source (with electronic power converter) and its performance for the unbalanced micro-grid. , Proved high impedance errors and different voltage levels based on the distributed power source.

Keywords : protection directional current power converter symmetric and asymmetric error maximum power point tracking solar cell