The integration of advanced technologies and renewable energy sources in modern cities requires a stable and efficient infrastructure, which is provided by the Software-Defined Smart Grid (SDSG). However, the transformation towards a digitalized energy network presents several security challenges that demand innovative solutions and meticulous attention. This research article provides a comprehensive survey of the security issues associated with SDSGs, offering insights into the vulnerabilities that may compromise the stability of our energy networks. The study examines a range of potential threats, including cyber-attacks, data breaches, and system manipulations, and provides a detailed analysis of their possible consequences. To mitigate these risks, we discussed various solutions, such as encryption techniques, anomaly detection, access control, and secure communication protocols. The effectiveness of these strategies is evaluated based on recent state-of-the-art studies, emphasizing their potential to safeguard the reliability and integrity of SDSGs. This thorough examination of security challenges and the latest solutions is intended to inform researchers, policymakers, and industry professionals about the evolving opportunities and challenges in the field of Software-Defined Smart Grid security. Ultimately, this paper aims to contribute to developing a secure and resilient energy infrastructure, supporting the sustainable future of our society.