Increasing penetration levels of solar PV, wind, and other distributed energy resources has resulted in the introduction of new and improved grid codes which require these technologies to provide grid support. As a result, a coordinated approach for controls at the power plant level is needed. High-level PPCs coordinate the lower-level controls (i.e. individual inverter controls) to provide the necessary functionality at the plant level.
PPCs typically control the plant’s active/reactive power output, power factor, voltage, and frequency. They may coordinate many inverters and sites, along with other static compensation equipment. PPCs are critical infrastructure on the modern grid, and validating their operation via hardware-in-the-loop (HIL) testing ensures that they will operate securely – and in line with the expectations of manufacturers and grid operators – when installed.
Vendors are often required to supply a detailed EMT model of their PPC to utilities. The RTDS Simulator has been used to validate these models against the performance of the actual hardware controller via HIL testing, providing increased confidence to the manufacturer and end user.
HIL testing allows for multiple devices to be tested simultaneously, providing unique insights on device interactions at the systems level that are often not revealed by conventional testing. The ability of PPCs to securely operate alongside existing protection and control can be verified using real hardware.
Including HIL testing in the factory and site acceptance testing process can improve project schedules. Troubleshooting in the lab allows for accurate replication of commissioning events and representation of a much wider range of contingencies than can safely be imposed on the real grid.
The impact of communication protocols – namely, any associated communication delays – are incorporated into the HIL test so the engineer can understand their impacts on system operation. This is an advantage of HIL over offline PPC simulation.
Freely configurable controls components allow the modeling of:
Control systems developed in MATLAB/SIMULINK can be directly imported.
The GTNETx2 network interface card is used to interface external devices to the RTDS Simulator via standard-compliant communication protocols, including: