Power supply units (PSUs) are indispensable components in electronic devices, including power adapters, server power supplies, communication power supplies, network security power supplies, industrial control power supplies, power battery chargers, etc. Whether these products are used intermittently, periodically, or 24/7, quality and reliability are crucial. In response to the trend of energy conservation and carbon reduction, global regulations on power consumption and energy efficiency are becoming increasingly stringent. For example, the EU’s CoC V5 and the US DoE Tier 6 energy efficiency standards both place higher requirements on power efficiency and standby power consumption. These regulations not only drive technological innovation in the power supply industry, but also promote the development of high-efficiency and energy-saving power supply products.