New Technology Applications and Development of DC Switching Power Supplies
Abstract: With the rapid development of electronic technology and communication industry, the application of high-frequency switching power supplies is becoming more and more widespread. The continuous improvement of switching frequency enables the performance of switching power supplies to be further optimized, with higher integration, lower power consumption, simpler circuits, and more reliable operation. This is the direction of the development of switching power supplies. At present, high-frequency switching power supplies have been widely used in various microwave stations of radio and television in our province. Based on this, this article compares traditional power supplies with modern high-frequency switching power supplies to introduce the new technology and advantages of high-frequency switching power supplies.
Keywords: high frequency; resonance; Switch; inversion
1. Composition principle of high-frequency switching power supply
High frequency switch rectifier generally rectifies and filters AC power directly through diodes into DC power, and then converts it into high-frequency AC power through a switching power supply. After being isolated by a high-frequency transformer, it is rectified by a fast recovery diode and filtered by inductance and capacitance before outputting, as shown in Figure 1.
1.1 Main Circuit
The entire process from AC grid input to DC output, including:
(1) Input filter: Its function is to filter out the clutter present in the power grid, while also hindering the feedback of local generated clutter to the public power grid.
(2) Rectification and filtering: Directly rectify the AC power supply of the power grid into smoother DC power, and provide stable DC power to the power factor correction circuit.
(3) Power factor correction: located between rectification filtering and inversion, it aims to eliminate harmonic current pollution caused by rectification circuits and reduce reactive power losses to improve power factor.
(4) Inverter: Convert rectified DC power into high-frequency AC power, which is the core part of high-frequency switching power supplies. The higher the frequency, the smaller the ratio of volume, weight, and output power.
(5) Output rectification and filtering: Provide stable and reliable DC power supply according to load requirements.
