The Improbable Real-Time Co-Simulation Between HYPERSIM and RTDS

The Company

The Operador Nacional do Sistema Elétrico (ONS) is the entity responsible for coordinating and operating the generation and transmission infrastructure within the Brazilian Interconnected Power System. As the 9th largest electricity market in the world, Brazil relies on ONS to manage a vast grid featuring six (with a seventh planned) large-scale HVDC transmission links. ONS ensures system safety and optimization while managing hydro, wind, and solar energy sources across the country.

The Challenges

• Vendor Lock-in & Diversity: ONS needed to expand its simulation capacity beyond its existing RTDS platform to increase commercial and technical flexibility.
• Multi-Infeed Complexity: The inverter sides of Brazil’s HVDC links are electrically close, requiring precise evaluation of mutual interactions (multi-infeed effect) during abnormal conditions.
• Interface Barriers: Implementing co-simulation between two different simulator manufacturers required a suitable, easy-to-program hardware interface for seamless data transfer.
• Synchronization & Latency: Ensuring reliable real-time synchronization between disparate platforms was critical to recreate simultaneous subsystem solutions without accuracy loss.
• Database Conversion: ONS required a tool that could easily convert existing “off-line” databases (like EMTP-RV) into real-time simulation environments.

The OPAL-RT Solution

A cooperative task between ONS and OPAL-RT led to the development of a synchronized co-simulation environment:

• HYPERSIM Platform: ONS invested in HYPERSIM due to its ease of creating customized models and its shared GUI with EMTP-RV for easy data conversion.
• FPGA-to-FPGA Communication: The project utilized Aurora-based communication protocols and OP5707 hardware to facilitate high-speed, low-latency data flow between HYPERSIM and RTDS.
• Transmission Line Interface: To manage inherent time delays between simulators, the team compensated for interface latency within the mathematical model of the transmission lines.
• IEEE 39 Bus Benchmark: The feasibility was first proven using a 3-phase line test on the IEEE 39 bus system, demonstrating highly convergent results between co-simulated and single-simulator models.

The Results

• Proven Co-Simulation Feasibility: Successfully demonstrated that HYPERSIM and RTDS can work synchronously in modeling large-scale power systems, breaking the vendor barrier.
• Heterogeneous Environment: ONS now operates an integrated facility featuring two different simulator suppliers and four HVDC C&P replicas from four different manufacturers.
• Future Regional Integration: The success opens the door for ONS to integrate with other simulation centers (like CEPEL and Furnas) in Rio de Janeiro, enabling shared expertise and resources.
• Accurate Event Analysis: The ability to study interactions between multiple HVDC links in a multi-infeed scenario significantly improves grid security and planning.
• Operational Flexibility: ONS is no longer limited by the simulator equipment provided by power utilities, allowing them to integrate any platform into their facility as needed.

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