摘要： A modern level of information technologies and computer facilities, as well as an actively developing digitalization of energy grids, allow us to reconsider approaches towards the development and improvement of the functions of automation and control systems for energy installations of various voltage classes. Primarily, it is a medium voltage, as the most common and, in connection with this, the most significant for end users. We propose a new 'Smart Grids Plus' concept for the digital energy grids design. These grids, in addition to the layers of intelligent energy grids and information communication channels, include a layer of diagnostic monitoring based on a passive fiber optic sensor networks. Sensor networks have a hybrid TWDM structure – information exchange channels and integrated fiber optical sensors – core, based on a new technology for address interrogation and multiplexing – special addressable fiber Bragg gratings, combined for arbitrary topologies. Some examples of diagnostic monitoring nets for temperature control of complete switchgear contacts and busbars are considered. Their principles of operation are discussed. The main advantages of these sensor networks are using addressable fiber Bragg gratings simultaneously with sensors and multiplexing elements, and using the PON structure simultaneously with sensor and communication networks.