Publication: Impact of Geomagnetically Induced Currents on High Voltage Transformers in Malaysian Power Network and Its Mitigation
Date
2021
Authors
Khurshid Z.M.
Ab Aziz N.F.
Rhazali Z.A.
Ab Kadir M.Z.A.
Journal Title
Journal ISSN
Volume Title
Publisher
Institute of Electrical and Electronics Engineers Inc.
Abstract
Geomagnetically induced current (GIC) is a ground end manifestation of geomagnetic disturbances (GMDs) and space weather arising from solar activity, which causes half-cycle saturation and represents a potential hazard for a stable and safe operation of earthed high voltage (HV) power transformers. Previous studies have shown that the impact of GIC is not limited to high and mid-latitude regions, but it can also affect power systems located in lower geographic latitudes. This work presents the impact of GIC on HV transformers in the Malaysian power network. A detailed power network was modelled using the Power System Computer-Aided Design for Electromagnetic Transients including Direct Current (PSCAD/EMTDC) software. The entire network was subjected to a geoelectric field strength of 20 V/km at the northward and eastward directions. The GIC analysis has determined the most critical locations in the power network model that are prone to high GICs. The simulation results demonstrated that the most vulnerable substations to GMD events and experience the most severe GICs were those located in the middle of the Malaysian power network. The GIC effects and saturation levels of four transformers' types in these locations have been investigated over the transmission network. Under the GIC condition, transformers were driven into half-cycle saturation and their reactive power consumption drastically increased. Thus, conventional GIC mitigation systems based on neutral blocking devices (NBDs) were proposed and connected to the power transformers to block the GIC flow in their neutral paths. It was found that the GIC protection modes in the mitigation systems effectively eliminate the injected GICs in the neutral paths and are able to prevent the saturation occurrence of the transformers. � 2013 IEEE.
Description
Computer aided design; Earth (planet); Electric grounding; Electric power transmission networks; Geomagnetism; Power transformers; Short circuit currents; Solar energy; Timing circuits; Transformer protection; Circuit faults; Computational modelling; Direct-current; Electro-magnetic transient; Geomagnetic disturbance; Geomagnetically induced currents; High-voltage transformers; Malaysian power network; Malaysians; Power networks; Power system computer aided designs; Power system computer-aided design for electromagnetic transient including direct current; PSCAD; Software; Space weather; Electric network analysis