The rapid development of communication industry has greatly promoted the development of communication power. High-frequency and miniaturized switching power supply and its technology has become the mainstream of modern communication power supply system. In the field of communication, the rectifier is often referred to as a one-time power supply, while a DC-DC (DC) converter is called a two-time power supply. The function of the primary power supply is to transform the single-phase or three-phase AC power grid into a DC power source with a Cheng value of 48V. At present, the traditional phase-controlled power supply has been replaced by high-frequency switching power supply, the High-frequency switching power supply (also known as switching rectifier SMR) through MOSFET or IGBT high-frequency work, switching frequency general control in the 50-100khz range, to achieve high efficiency and miniaturization.
In recent years, the power capacity of the switching rectifier has been expanding, and the single capacity has expanded from 48v/12.5a and 48v/20a to 48v/200a and 48v/400a. Because of the wide variety of integrated circuits used in communication equipment, its power supply voltage is also different, in the communication power supply system using high power density of high-frequency DC-AC power supply module, from the middle bus voltage (generally 48V DC) to transform into a variety of DC voltage, which can greatly reduce the loss, convenient maintenance, and installation, The increase is very convenient. Generally can be directly installed on the standard Control Panel, two times the requirements of the power supply is high power density. Because of the increasing capacity of communication, the capacity of communication power will also increase continuously.