Multi-Hardware-in-the-Loop Laboratory Testing of Power Converters and Intelligent Electronic Devices for Large-Scale Power System Applications

This paper presents an approach and a corresponding laboratory infrastructure for multi-hardware-in-the-loop (M-HiL) testing of power converters and intelligent electronic devices (IEDs) with wide area features for power system monitoring and control. The basis for the testing environment is a digital real-time simulation (RTS) platform which can be utilized for phasor-based or hybrid phasor and electromagnetic transient (EMT) power system simulation. A high-bandwidth power amplifier is used for interfacing the real-time simulated power system to the power hardware. The necessary elements and their interfaces required for realizing the M-HiL testing are highlighted in the paper. Finally, a complete example of an M-HiL test based on real-time simulation of the Nordic 44 (N44)-bus power system model is presented. The test setup includes two phasor measurement units (PMUs) with their corresponding communication layers and a converter configuration for scaled emulation of the HVDC transmission system of an offshore wind farm. The configuration also includes a grid forming converter unit operated in parallel to the grid-side HVDC terminal. The presented test demonstrates how a grid forming converter operated as a Virtual Synchronous Machine (VSM) can provide frequency support to the Nordic power system and how this support would be recorded by the PMUs.