# An Integrated Testbed for Power System Cyber-Physical Operations Training
## 4 CPS Testbed Applications  
Testbed development requires the integration of different types of system components, which is a key challenge for many CPS projects. The TTU CPS testbed has been designed and periodically upgraded to perform co-simulation and reconfiguration studies. Figure 2 shows the CPS testbed at TTU with hardware components (right) and the corresponding network architecture (left). The testbed has hybrid architecture and can include physical hardware components and emulated power systems following the power hardware-in-loop approach. In addition, it utilizes industry-standard equipment and communication protocols. The laboratory setup is completely reconfigurable and primarily employs hardware components from the leading industry supplier power systems. However, its interoperability is second to none, as it supports multiple other vendor components. It can perform real-time and end-to-end system simulations with the HIL capability to evaluate the existing prospects of the cyber-physical system alongside advanced management systems and SCADA applications via OPAL-RT. The OPAL-RT real-time simulator (OP5700) is a potent target computer with a high-end reconfigurable FPGA, signal conditioning for up to 256 I/O lines, and 16 high-speed fiber-optic SFP ports. SEL-35 IS, SEL-421, SEL-751, and SEL-651R are advanced protection, automation, and control system devices. The protective relays utilize analog I/O and digital I/O cards to reflect the values of the physical modeling. They communicate with Survalent SCADA or RTAC to receive any control command and execute it. All of these devices are equipped with synchro-phasor applications, allowing them to capture precise phasor measurements from different nodes in the power system. The synchro-phasor measurements can be transmitted using protocols such as DNP3, IEEE-C37.118, or SEL fast message protocols. This enables the exchange of data with other devices and systems in a standardized and interoperable manner [51]. Additionally, they can receive commands using the IEC-61850 protocol, which facilitates seamless integration with other intelligent electronic devices in the power grid. The testbed, as shown in Figure 2, consists of a regular switch, a managed switch (SEL-2730M), and an SDN switch (SEL-2742S) for communications. SEL-2730M offers advanced features and configuration options for networking applications in industrial environments. The managed switch (SEL 2730M) connects and provides the physical link to all the devices via ethernet cables. In contrast to the regular switch, the managed switch provides an additional security layer against cyberattacks with its functionality, such as Port Management, MAC address filtering, and VLAN creation. The RTAC is integrated into the testbed as the data concentrator. It can also perform any necessary control function depending on the user's requirement. It combines the functionality of a protective relay with the capabilities of a programmable logic controller (PLC) and RTUs [52]. The controllers receive the control command from the Survalent SCADA or RTAC, or a Python-based algorithm can be run on it to implement the advanced management function and generate its control command. The host computer is responsible for both performing the physical and communication layer modeling and running Survalent SCADA. The first module is based on an integrated sub-transmission and distribution system model that is simulated along with SEL devices and Survalent SCADA to analyze protection performance. The second module develops a standalone cyberattack analysis to clarify the impact of these actions on the data exchange. The third module is compounded by a wind turbine system connected to a distribution network. This simulation model is integrated with Survalent SCADA and EXata CPS to analyze the network performance under cyberattack in the wind turbine operation.