Real-Time Hybrid Energy System Emulation and Control Using Hercules and the Wind Hybrid Open Controller

To address the resource variability associated with variable renewable energy systems, particularly wind power and solar power, recent entries into the interconnection queue (the queue of proposed power plants waiting to connect to the power grid) have increasingly included the addition of battery storage or multiple generation sources. However, with such hybrid power plants coming online, specialized tools are needed to evaluate their performance and determine how they will contribute to grid stability and power supply-demand balancing. To address these needs, this tutorial article presents Hercules, a hybrid plant simulator developed at the National Renewable Energy Laboratory, and the Wind Hybrid Open Controller (WHOC), a library of baseline closed-loop controllers for such hybrid systems. In presenting Hercules and WHOC, we describe each at a high level to give readers an understanding of their purpose, basic functionality, and interactions; then, we describe the inputs needed to run a simple simulation using the Hercules/WHOC ecosystem. We finish with an example simulation that demonstrates the tools in action and showcases tangible and intuitive results that highlight the potential benefits of using Hercules and WHOC for hybrid power plant evaluation and management.