Thread Content
The power supply is the source of energy for all electronic devices and is a fundamental component that ensures their operation. According to relevant statistics, power supply failures account for approximately 40%–50% of the total failure rate of electronic devices. To this end, certain basic requirements must be imposed on the power supply, including performance and electrical characteristics. Next, the performance requirements for switching power supplies will be discussed: 1. High reliability. The Mean Time Between Failures, or MTBF, is an important indicator for measuring the reliability of power supplies. According to the standards for general-purpose power supplies, a minimum requirement for this reliability metric is an MTBF of 3000 hours or more. Aerospace power supplies have higher requirements; with the continuous improvement of manufacturing technologies and processes, their MTBF can exceed 500,000 hours. The conversion is 78.6 years. 2. High security. The designed switching power supply should meet the safety performance requirements specified in relevant standards or specifications, such as insulation requirements. Requirements for dielectric strength, as well as requirements to prevent electric shock to people, are in place to avoid power supply failures under extreme conditions or in harsh environments, which could endanger the safety of people or equipment. 3. Good maintainability. The Mean Time To Repair MTTR is an important indicator for measuring the repairability of power supplies. In the event of a power supply failure, it should be possible to diagnose the location of the fault promptly; without the need for special tools or advanced skills, the fault can be resolved, and the faulty components and modules can be replaced in a short time. It is generally required that the MTTR be less than 30 minutes. In addition to requiring the power supply to have a fault self-diagnosis function, advanced design and manufacturing technologies and processes must be employed, such as standardization, modularization (e.g., drive modules on the circuit board), and power electronics integration in the design and manufacturing process. 4. High power density. Increase the power capacity per unit volume (W/cubic cm) and the power capacity per unit mass (W/g) of the power source, so as to reduce its volume and mass and facilitate installation, integration, mobility, and use by users. The key to achieving high power density is to increase the switching frequency and reduce losses; accordingly, it is necessary to use low-loss power devices, insulating materials with high thermal conductivity and high insulation properties, as well as soft-switching circuit structures.