The wireless local area network technologies are attractive solutions to upgrade the communication network of the traditional electrical substation toward smart electrical substation. Unfortunately, the wireless communication network suffers from additional drawbacks compared to wired technologies such as cyber threats in particular the common wireless channel. The current work suggests a cybersecurity model for the wireless communication network (WCN) that serves the substation automation system (SAS) of electrical substations. The adopted model protects the wireless communication between the high-voltage devices and the switched access point (S-AP) in the electrical substation using wifi protected access 3 (WPA3) security scheme. This work proposes a new architecture scheme to provide a secure and reliable key management module based on WPA3. Hence, a local authenticator is responsible for distributing the keys safely rather than the remote authentication dial-in user service (RADIUS) server. In addition, a lightweight security scheme as possible is handled to overcome the challenges of SAS system performance requirements. The results indicated that the adopted ciphering algorithms do not break the latency requirements of real-time protection of SAS (less than 4 msec).