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 halfcycle 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.

It has been shown that the scale of damage in buildings with steel reinforcement, due to direct lightning strikes, is insignificantly small compared to lightning effects on buildings with no such steel reinforcement. Observed small-scale damages are also confined to points of strike; hence the only risk for occupants and properties is injury or damage caused by falling materials. A large number of such cases have been observed in Sri Lanka and Malaysia. All damaged structures, observed in this study, have a steel reinforcement structure, which may not be in compliance with specifications in IEC 62305-3, for it to act as the sole down conducting system. Such observation prompts us to re-examine specifications set forth in standards, which are difficult to be achieved in practice and also not applicable to buildings that have already been constructed. Existing recommendations prevent engineers from using steel reinforcement as the down conductor in many cases; a fact that leads to the addition of large amount of copper unnecessarily into the environment, non-installation of protection systems or adoption of non-conventional systems.

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