Changing Protection in Real Time
As soon as protection uses an outside variable to change an operating characteristic it becomes adaptive, but levels of adaptibility and the need for it are changing. As renewable generation resourses, such as wind and solar, replace large synchronous machines, protection needs change. This paper focuses on how changes in the bulk power system impact protection settings and how those settings can be optomized to reflect changing system conditions. Techniques for initiating and communicating the change commands are discussed. The interconnection of protection, wide area control, and automation are evaluated to present not only what is and can be done today but what will need to be and could be done tomorrow. Communications between these systems is a limiting factor, and an enabling factor, for adaptive protection to make it possible to maintain system stability during the rapid changes we are seeing. The speed of the message from an Energy Management System (EMS) to relays impact the protection characteristics that can be changed. The protocol used to send a message impacts both the speed and the devices that can be made adaptive. The information available to be transmitted by the protocol defines how adaptations can be made. True adaptive protection is a combination of advanced algorithms, communications, and shared information. Forces outside the control of the electric power industry have determined that changes are coming to force new requirements on protection and control. This paper presents how adaptive solutions will meet those new requirements.