Substation automation system is the key element in protecting, monitoring and controlling of power grid system. Programmable logic controllers (PLCs) and Intelligent Electronic Devices (IEDs) are widely employed to carry out automation process in substations. In order to provide efficient control and to protect against cyber threats, understanding the functionalities of these devices is of core importance. However, as commercialised products do not provide sufficient information about the hardware and firmware of the devices publicly available, it is also a universal challenge for conducting research in general industrial control systems. Moreover, in substations where IEDs are employed, IEC 61850 protocol is utilised. In order to conduct evaluation of automation control or cyber-attack research on a system that incorporates both PLCs and IEDs for communication, software that can support both the traditional Modbus protocols and also IEC 61850 protocol is necessary. As a solution, OpenPLC61850, which is an enhancement to the existing OpenPLC is developed by our team in Advanced Digital Sciences Center (Illinois at Singapore Pte. Ltd.), Singapore.
The overview of the software design is illustrated in the figure. The blocks highlighted in orange in the figure represent the functionalities that are available in the current OpenPLC software. The editor in the OpenPLC supports IEC 61131-3 programs (structured text, instruction list, sequential function chart, ladder diagram and function block diagram) and supports Modbus and DNP3 protocols. The blocks highlighted in green are the enhancements designed by our team in order to make the OpenPLC support IEC 61850 protocols. The components include IEC 61850 server and client modules that are used to handle the incoming MMS messages and sending control commands. In order to accomplish the communication between IEC and OpenPLC modules, the Mapper Program has been defined. Further, the IEC 61850 protocol support in the software is established through libiec61850. The detailed description on the technicalities of implementation and case studies can be found in the papers listed under 'Publications'.