A modular multilevel converter (MMC) in a high-voltage direct-current (HVDC) transmission system consists of an electric-coupled physical system and a communication-coupled cyber system. leading to a cyber-physical system (CPS). Such a CPS is vulnerable to false data injection attacks (FDIA). which are the main category of cyberattacks. https://herbsdailyes.shop/product-category/kits-and-trays-first-aid-kits/