Since 1996, Tongfeng has been engaged in the research and development of power electronic capacitors. Its product range includes oil-immersed square stainless steel cases, dry square stainless steel cases, dry square plastic cases, dry cylindrical aluminum cases, etc. These products are widely used for DC support, connection, AC/DC filtering, circuit protection, and other purposes in various power equipment such as locomotives, trams, trolleybuses, mining locomotives, ships, hybrid electric vehicles, pure electric vehicles, wind and solar photovoltaic power generation equipment, as well as flexible power transmission and transformation systems and smart grids. The products have obtained IRIS certification.