Three conditions for switching power supplies
Switching
Power electronics operate in a switching state rather than a linear state
High Frequency
Power electronics operate at high frequencies rather than at low frequencies close to the industrial frequency.
DC
Switching power supplies output DC instead of AC or they can output high frequency AC such as electronic transformers.
Classification of switching power supplies
People in the field of switching power supply technology is the side of the development of related power electronic devices, while the development of switching inverter technology, the two promote each other to promote the switching power supply to more than double-digit annual growth rate toward the light, small, thin, low noise, high reliability, anti-jamming direction of development. Switching power supply can be divided into AC / DC and DC / DC two categories, there are also AC / ACDC / AC such as inverter DC / DC converter has now achieved modularity, and the design technology and production processes at home and abroad have matured and standardized, and has been recognized by the user, but the modularity of the AC / DC, because of its own characteristics make the process of modularization, encountered a more complex technology and process manufacturing Problems. The following are two types of switching power supply structure and characteristics to explain.
Development trend of switching power supply technology
The development direction of switching power supply is high frequency, high reliability, low consumption, low noise, anti-interference and modularization. As switching power supply light, small, thin key technology is high-frequency, so the major foreign switching power supply manufacturers are committed to the simultaneous development of new highly intelligent components, in particular, to improve the loss of the secondary rectifier device, and in the power ferrite (Mn?Zn) materials to increase scientific and technological innovation to improve the high frequency and larger flux density (Bs) to obtain a high degree of magnetic performance, and the miniaturization of the device is also a key technology. The application of SMT technology has led to significant progress in switching power supplies, and components are arranged on both sides of the circuit board to ensure that the switching power supply is light, small and thin. The high-frequency of switching power supply is bound to innovate the traditional pWM switching technology, and the soft-switching technology that realizes ZVS and ZCS has become the mainstream technology of switching power supply, and has greatly improved the working efficiency of switching power supply. For high reliability indicators, the U.S. switching power supply manufacturers by reducing the operating current, reduce the junction temperature and other measures to reduce the stress of the device, making the reliability of the product greatly improved. Modular is the overall trend of the development of switching power supply, modular power supply can be used to form a distributed power supply system, can be designed as N + 1 redundant power supply system, and to achieve parallel mode capacity expansion. Switching power supply operation noise for this shortcoming, if the pursuit of high-frequency noise is also bound to increase, and the use of part of the resonant conversion circuit technology, in theory, can achieve high-frequency and can reduce the noise, but part of the practical application of the resonant conversion technology is still a technical problem, it is still necessary to carry out a great deal of work in this field, in order to make the technology to be practical. The continuous innovation of power electronics technology, so that the switching power supply industry has a broad development prospects. To speed up the development of China's switching power supply industry, it is necessary to take the road of technological innovation, out of the joint development of production, research and development with Chinese characteristics, to contribute to the rapid development of China's national economy.
