| The aim of the thesis is to design efficient and accurate co-simulation interfaces between off-the-shelf heterogeneous real-time simulators. Co-simulation in this context refers to the distribution of subsystems of a complex power system among the different simulator platforms.;The design of an efficient communication interface is the key step of the co-simulation process. The Internet is a popular option used for coupling different real-time simulator platforms. But, factors such as delay, throughput and LAN congestion are disadvantages of the internet based communication. Therefore, co-simulation interfaces that overcome the data loss during communication and that increase the computational efficiency of the simulators need to be developed.;In this thesis, the two real-time electro-magnetic transient simulators used in the co-simulation are the Real-Time Digital Simulator (RTDS) and the Opal-Real-Time (Opal-RT). The work establishes analog and digital multi-rate co-simulation interfaces between these simulator platforms. The analog interface is designed using the peripheral I/O ports of the simulators and is demonstrated with the notional IPS MVDC ship model. The digital interface is established using the FPGA based reconfigurable I/O platforms of the simulators. To further analyze the co-simulation interfaces, round-trip latency and accuracy tests are conducted, and the stability of the co-simulation is investigated. From these tests, it is observed that the latency of the analog interface is decreased to 480 mus compared to 0.2 s observed when the internet is used as the communication medium. And, the results from the 11-bit parallel digital interface indicate that the design is feasible. Since it uses FPGAs for the data exchange, it overcomes the noise due to traditional A/D and D/A converters.;In summary, this thesis presents a low latency analog interface and a high speed FPGA based digital interface for the real-time simulators. The importance of the co-simulation interfaces to multi-rate co-simulation techniques is studied and analyzed. |
