How to Design a High-Capacity Switching Power Supply?
In the fields of communication and power, the required DC power supply system outputs different currents and voltages. For large capacity power supply systems, multiple small capacity power supply modules of the same voltage level are often connected in parallel. However, if there are too many parallel power supply modules, it is not conducive to current sharing and reliability. Therefore, users urgently demand the emergence of large capacity power supply modules. Based on this background, the author developed a large capacity switching power supply. At present, large capacity switching power supplies are generally composed of a main circuit and a control circuit, while intelligent switching power supplies often have a numerical control system composed of a microcomputer - while realizing intelligent functions, some key parameters and various fault signals of the switching power supply are also detected and transmitted to the upper computer. At the same time, some control variables of the upper computer can also be controlled by the microcomputer system to control the output voltage and current of the switching power supply. This article uses a PIC microcontroller as the intelligent guidance control circuit and main circuit of the switching power supply to work. The inverter circuit in the main circuit of a large capacity switching power supply is generally an H-bridge structure, which can adopt either hard switching or soft switching methods. Both methods are widely used in large capacity switching power supplies abroad. In order to simplify the circuit structure and production process, hard switch technology is adopted in this power supply. However, the switching losses of hard switches are greater than those of soft switches, so it is crucial to choose switching devices with lower operating frequencies and losses reasonably. If the design is reasonable, hard switch technology still has great vitality. Due to the mature control methods, main circuit structures, and related technologies commonly used in switching power supplies, this article only introduces several new technologies in the design of large capacity switching power supplies: PFC technology, operational stability, and multi power parallel current sharing
