Future power plant control - Integrating

Today's power plants are highly automated. All subsystems of large thermal power plants can be controlled from a central control room. One subsystems area is the electrical auxiliaries for the unit transformer, the grid connection, excitation, synchronization, generator/unit protection, auxiliary transformers, HV-, MV-and LV-switchgear. In the past, these electrical devices were all hardwired to the DCS and I/Os. To this day, horizontal communication between electrical devices is still hardwired. In the last decade, serial communication protocols were introduced. Unfortunately, standardization of these protocols went in different directions. Today there are several standards on the market. Most of them are incompatible with others. In substation automation, the newly developed IEC 61850 standard was released in 2004. IEC 61850 defines interoperable function blocks, called logical nodes, that communicate over a network with other functions, regardless on which suppliers' device they are implemented. IEC 61850 separates application and communication layers, which enables one part to be changed without impacting the other part. New future communication technologies can be easily adapted to IEC 61850 which will make applications future proof over their service life. In future, it will be possible to modify or extend electrical without replacing the entire substation automation system. IEC 61850 is expected to be a future standard in power plant electrical systems, at least for HV and MV. It will have application-specific extensions; e.g., IEC 61850-7-420 (formerly IEC 62344) for hydro power applications. This results in new requirements for state-of-the art power plant control systems. Users can seamlessly monitor and operate electrical devices the same way they do the process control. This paper discusses various aspects of the implementation of the standard in power plants and shows how devices integrate into ABB's control system environment. Traditional power plant control systems focus on controlling the process operation of the power plant. The power plant control system controls the different processes to achieve maximum power output at lowest operational cost. Today's state-of-art control systems are highly automated, and in many installations, allow one operator in a central control room to manage the entire production. In the past, electrical systems were already coupled to the process control system using parallel copper cable hardwired interfaces. Due to cabling and engineering costs, the bandwidth of this kind of interface is very limited; e.g., enabling the display of a single line diagram (SLD) overview in the central control room. For additional signals, the number of I/O …