Guided by China's action plans for achieving "carbon peak" by 2030 and "carbon neutrality" by 2060, the installed capacity and power generation share of wind and solar energy are increasingly rising, with their proportion in the energy structure continuously growing. However, new energy sources such as photovoltaic (PV) and wind power are characterized by volatility, intermittency, and randomness. Concurrently, against the backdrop of high-quality economic development, the proportion of electricity consumption by the tertiary industry and residential households is gradually increasing, leading to an expansion of the peak-to-valley difference rate in the load curve. Instabilities on both the generation side and the user side can significantly impact the stability of grid operation. To ensure a smooth transition of the energy structure, flexible resources such as energy storage are required for regulation. As a high-quality flexible resource, energy storage can play roles in peak shaving, frequency regulation, and backup on the power source side, grid side, and user side, and is gradually becoming an essential requirement for ensuring the development of the IBR-dominated power system.
Many regions have established energy storage development targets for the "14th Five-Year Plan" period, promoting energy storage development through multiple measures. The scale of energy storage construction is projected to reach 67 GW by 2025. Nearly 30 provinces in China have stipulated mandatory energy storage allocation requirements within guaranteed scales, with clear requirements for supporting energy storage construction for centralized PV, distributed PV, and wind power projects. Cascaded energy storage systems adopt a three-phase star-connected cascaded H-bridge topology, capable of directly outputting 0.4~35 kV three-phase AC voltage without a transformer for grid connection. A single system can achieve an output power exceeding 10 MW.
How to verify the grid-connection characteristics, power station-level safety, and grid-friendly interactive functions of new PV and energy storage technology routes—especially when using cascaded H-bridge multilevel converters as grid-tied converters for optical storage power stations—poses a challenge. Given the numerous interfaces and complex model structures involved, traditional hardware-in-the-loop (HIL) testing software and hardware can hardly meet the demands of practical testing applications.
In response to the testing needs arising from the rapid development of the cascaded PV and energy storage industry, KeLiang has proposed simulation testing solutions and test systems specifically for cascaded PV and energy storage power station systems. These solutions support design verification, R&D process verification, factory acceptance testing, and grid-connection certification for inverters and power station-level systems in the optical storage industry.
