我国70年代统一设计的SL7系列节能铝线变压器,性能已基本接近德国DIN42500和DIN42503的损耗水平。后因铝线价格不断上涨,各地又自行设计出S_7系列铜线节能变压器,性能水平与SL_7完全相同,价格也为广大用户所接受,成为我国变压器市场的主导产品。1985年,沈阳变压器研究所,设计了 China’s SL7 series of energy-saving aluminum wire transformers that were designed in China in the 1970s have almost reached the level of losses of Germany’s DIN42500 and DIN42503. After the rising price of aluminum wire, various localities have independently designed the S_7 series of copper line energy-saving transformers. The performance level is exactly the same as that of SL_7, and the price has also been accepted by customers. It has become the leading product in China’s transformer market. In 1985, Shenyang Transformer Research Institute, designed