Design and implementation of a teaching experiment for oscillation analysis and impedance-reshaping suppression for renewable energy integration based on the Real-Time Laboratory

Integrating renewable energy sources, such as solar and wind, into the power grid presents significant stability challenges, notably complex broadband oscillations, that threaten operational reliability. Traditional teaching methods, which rely solely on digital simulation or physical experiments, exhibit limitations in cultivating the practical skills required of future engineers. This work develops a hybrid digital–physical simulation platform to provide an integrated, high-fidelity, and safe environment for analyzing and validating oscillation suppression strategies. The platform simultaneously serves as an advanced educational tool for enhancing student competencies in hardware operation, system analysis, and problem-solving for modern power systems.

This study leverages the Real-Time Laboratory (RT-LAB) real-time simulation system to develop a hardware-in-the-loop (HIL) platform that integrates a high-fidelity digital environment with physical power electronic hardware. The digital subsystem models a comprehensive power system, incorporating renewable sources, including photovoltaic (PV) stations with grid-forming inverters, synchronous generators, transformers, transmission lines, and loads, which are simulated in real time to replicate dynamic grid behavior. The core innovation is the seamless incorporation of a physical voltage-source converter (VSC) prototype—a 10 kW three-phase two-level VSC controlled by a TMS320F28335 digital signal processor (DSP)—within the simulation loop. The control algorithm of the VSC actively reshapes the output impedance of renewable sources, specifically targeting the damping of oscillation modes. The digital and physical components are interfaced through signal conditioning equipment: voltage signals from the simulator are amplified to drive the VSC, while currents are measured by Hall-effect sensors and fed back to the digital model, ensuring closed-loop, real-time interaction in a safe, controlled environment. The experimental methodology follows a four-stage structured workflow, beginning with system modeling to define oscillation scenarios (e.g., subsynchronous resonance from series compensation), progressing to hardware integration and configuration, followed by the implementation and tuning of the impedance reshaping strategy on the DSP of the VSC based on stability criteria, and culminating in validation through disturbance testing to assess system response with and without the active VSC damping. This integrated approach validates the technical efficacy of oscillation suppression strategies and provides an immersive educational framework for practical skill development.

The platform demonstrates dual functionality as a research and teaching tool. Technically, the impedance-reshaping VSC effectively suppresses broadband oscillations. In subsynchronous oscillation scenarios, it significantly reduces the critical oscillation amplitudes in less than 1 s, rapidly stabilizing power and current waveforms. Tests with a grid-forming PV inverter further confirm its efficacy in enhancing system damping and small-signal stability across different oscillation mechanisms. Educationally, the platform equips students with a hands-on, end-to-end experimental experience workflow, covering device recognition, safety-aware wiring, theory-based parameter tuning, real-time operation, and performance analysis. Assessments indicate marked improvement in students’ hardware competencies, their ability to correlate time-domain oscillatory behavior with frequency-domain stability analysis, and their innovative design of mitigation strategies.

This hybrid simulation platform advances oscillation research and power engineering education. Technically, it provides a reliable, safe, and cost-effective HIL testbed for validating advanced damping devices, accelerating the transition from control theory to hardware implementation. Pedagogically, it bridges theoretical knowledge and practical engineering by integrating real hardware into a simulated grid, thereby overcoming the limitations of traditional teaching methods. The platform fosters interdisciplinary expertise in power electronics, system stability, real-time simulation, and hardware integration. This approach is recommended for advanced laboratories and industrial research and development toward stabilizing modern, renewable-rich power systems.