Abstract—Numerous innovative smart grid technologies are deployed in modern power systems, making a power system a typical cyber-physical system (CPS). The increasing coupling between a physical power system and its communication network requires a smart grid simulator to run in a cyber-physical environment for cyber security research. In addition, smart grid technologies introduce numerous access points to the communication network, making cyber security a big concern in smart grid planning and operation. In this paper, a simple real time CPS test bed, implemented in RTDS and OPNET, is discussed. The setup of the test bed is introduced. Results of a case study simulated in the test bed to study the impact of cyber attacks on system transient stability are presented. The simple test bed was capable of accurately modelling a smart grid while providing user-friendly modeling experience. Index Terms—cyber-physical system, test bed, cyber security, smart grid, cyber attack, real time simulation, RTDS, OPNET I.

Abstract—To understand security vulnerabilities of communication protocols used in power systems, a real-time framework can be developed to conduct vulnerability studies. The framework should implement protection mechanisms against vulnerabilities and study their effectiveness. In this paper, a real-time cyber-physical framework or test bed is presented. It integrates a real-time power system simulator and a communication system simulator to study the cyber and physical system vulnerabilities in smart power grids. The power system simulation is implemented using the Real-Time Digital Simulator (RTDS®) power grid simulator, with LabVIEW and PXI modules that simulate the supervisory control and data acquisition (SCADA) system and intelligent electronic devices (IEDs). The communication system simulation is implemented using Opnet’s System-in-the-Loop (SITL) simulator and open source Linux tools and servers. Results of two cyber-attacks on the Modbus/TCP protocol are discussed and improvements to the test bed for protocol attack detection and mitigation are proposed.