The Korea Electrotechnology Research Institute (KERI) has established a photovoltaic inverter test system based on an SPS linear amplifier, capable of directly testing 350 kW mediumscale photovoltaic inverters. Physical images of some of the system cabinets are shown below:

The real-time grid simulator (RTNS) at Newcastle University's Smart Grid Laboratory utilizes models capable of interacting with the actual lab environment to conduct comprehensive realtime simulations of power grids. After integrating Triphase power amplifiers, the research methodology shifted directly from traditional HIL to PHIL (PowerHardwareintheLoop). The realtime grid simulation model can be linked via a digital interface to a threephase fourquadrant variable frequency drive capable of delivering controllable voltage waveforms and timing signals. This enables interaction between real lowvoltage grid equipment under test and the largescale grid model simulated by the realtime grid simulator, making it possible to conduct complex studies on various capabilities of future grid technologies.

Based on the Windows platform, EMTP-RV is a new generation graphical electromagnetic simulation software. This software has been widely adopted by numerous power companies in Europe and North America. This case study presents the application of EMTP-RV in assisting Bombardier Inc. of Canada to conduct in-depth research on the performance of the main power supply protection system in locomotive traction systems.

French automotive parts supplier Valeo specializes in designing, manufacturing, and selling components, integrated systems, and modules for passenger cars and trucks, along with providing related services. RT-LAB's Rapid Control Prototyping (RCP) solution accelerated Valeo's development of innovative motor drive systems. In this case, Valeo aimed to develop a new electric power system for electric vehicles.

At the Valeo R&D center in Créteil, France, developing and testing new algorithms and control strategies previously required a physical prototype test bench. This approach was costly and timeconsuming, as it typically involved writing and executing extensive computer code, while also demanding programming expertise from the development engineers. Due to limited flexibility, engineers were unable to adjust or modify control loops in a timely manner, making troubleshooting more difficult.

With the advancement of power electronics technology and the increasing integration of microgrids into the power grid, flexible DC distribution networks are becoming a research focus worldwide due to their advantages, such as lower line construction costs, reduced power loss, higher power supply reliability, and lower microgrid integration costs.

To conduct in-depth research on flexible DC distribution technology, Shenzhen Power Supply Bureau Co., Ltd. took the lead, collaborating with institutions like Tsinghua University and Zhejiang University to undertake the research for the Ministry of Science and Technology's 863 Program project—"Research and Application of Key Technologies for Smart Distribution Based on Flexible DC." This project addresses prominent issues in urban AC distribution networks, such as power quality problems and the rapid development of distributed generation. It investigates the use of flexible DC technology in urban distribution networks, including dedicated power supply to specific users and using voltage source converters (VSC) to improve AC distribution power quality. Additionally, it explores technical solutions like directly connecting distributed generation and energy storage devices on the DC side to supply DC loads directly. These approaches aim to solve several critical problems in urban distribution networks and expand the application areas of flexible DC technology.

KeLiang utilized the RT-LAB real-time simulator to establish a hardware-in-the-loop (HIL) research and testing platform for a flexible DC distribution control and protection system. This platform played a crucial role in the project, assisting Shenzhen Power Supply Bureau in successfully completing the first-phase simulation experiments for the flexible DC distribution network.