  Smart grids are replacing conventional power grids due to rising electricity
use, failing infrastructure, and reliability problems. Two-way communication,
demand-side administration, and real-time pricing make smart grids (SGs)
dependent on its communication system. Manual network administration slows down
SG communication. SG networks additionally utilize hardware and software from
several vendors, allowing devices to communicate. Software-defined SGs (SD-SG)
use software-defined networking (SDN) to monitor and regulate SG global
communication networks to address these concerns. SDN separates the data plane
(routers and switches) from the control plane (routing logic) and centralizes
control into the SDN controller. This helps network operators manage
visibility, control, and security. These benefits have made SDN popular in SG
architectural and security studies. But because SD-SGs are vulnerable to
cyberattacks, there are concerns about the security of these SD-SG networks.
Cybercriminals can attack software-defined communication networks, affecting
the power grid. Unauthorized access can be used to intercept messages and
introduce false data into system measurements, flood communication channels
with fraudulent data packets, or target controllers, a potential single point
of failure, to cripple SDN networks. Current research reflects this paradigm as
defense and security against such attacks have developed and evolved. There is
a need for a current study that provides a more detailed analysis and
description of SD-SG network security dangers and countermeasures, as well as
future research needs and developing threats for the sector. To fill this void,
this survey is presented.
