The escalation of anti-tariff policy protests in California in early June has led to the stagnation of customs clearance procedures for some imported power equipment at the Port of Houston. Previously, the US, citing "national security" concerns, seized transformers made in China and imposed a 25% tariff on them, resulting in the delayed delivery of 345kV main transformers for substations in places like Colorado and Denver. The Electric Power Research Institute (EPRI) in the US states that such transformers are often custom-made, with a replacement cycle of up to 18 months. Currently, California grid companies have no choice but to use outdated switchgear cabinets to maintain operations. However, the reduced heat dissipation efficiency has triggered local power rationing warnings. The persistence of trade barriers is continuously exacerbating the aging of US grid equipment and significantly increasing the power supply risks. This not only affects the stability of local power supply but also poses a serious obstacle to the advancement of relevant grid upgrade projects.