In today's era of energy efficiency, the energy-saving performance of switching power supplies in low-power standby mode is becoming increasingly important. Reducing no-load losses is one of the key links to improve the energy utilization of switching power supplies, which involves the comprehensive application of multiple energy-saving technologies.
In low-power standby mode, a common energy-saving technology is to adjust the switching frequency. Usually, switching power supplies operate at a higher switching frequency when fully loaded to reduce the size and weight of magnetic components, but when no-load or light-loaded, higher switching frequencies will lead to greater switching losses. By adopting frequency conversion technology, when the power supply enters low-power standby mode, the switching frequency is reduced, which can significantly reduce the number of switching tubes, thereby reducing switching losses. For example, some switching power supplies use frequency jitter technology to randomly change the switching frequency within a certain range in standby mode, which not only reduces the average switching frequency, but also effectively disperses the electromagnetic interference spectrum and reduces the electromagnetic interference intensity.
The application of energy-saving chips is an important means to reduce no-load losses. Such chips usually have low quiescent current and multiple energy-saving modes. For example, some chips will automatically enter a dormant state in standby mode, shut down unnecessary internal circuits, and retain only basic control functions, thereby greatly reducing the chip's own power consumption. At the same time, energy-saving chips also have high-precision voltage and current detection functions, which can accurately control the output voltage and current to avoid additional losses caused by overcurrent or overvoltage. In addition, some chips also support green mode control, automatically adjust the working mode according to the load conditions, and adopt more energy-saving control strategies when no-load or light-loaded.
Transformers are key components in switching power supplies, and their losses account for a large proportion when no-loaded. Optimizing transformer design can effectively reduce no-load losses. On the one hand, the selection of high-permeability, low-loss magnetic materials, such as amorphous alloys or nanocrystalline materials, can reduce core losses. On the other hand, the transformer winding structure is reasonably designed to reduce winding resistance and copper loss. For example, using multi-strand twisted wire instead of single-strand wire as winding can reduce additional resistance losses caused by skin effect and proximity effect. In addition, optimizing the air gap design of the transformer can improve the energy storage efficiency of the transformer and reduce energy loss in the transformer.
Intelligent control strategies play a core role in reducing no-load losses. For example, a control method combining pulse frequency modulation (PFM) or pulse width modulation (PWM) with PFM is used. When no-load or light-loaded, switch to PFM mode and dynamically adjust the frequency of the switching pulse according to the load demand, so that the power supply only provides energy when needed, avoiding continuous switching action. When the load increases, it automatically switches to PWM mode to ensure the stable output of the power supply. This intelligent control strategy can adjust the working mode of the power supply in real time according to the actual load conditions to achieve high efficiency and energy saving.
The auxiliary power supply circuit provides power for the control chip and other auxiliary circuits of the switching power supply. In the low-power standby mode, optimizing the auxiliary power supply circuit can reduce its own power consumption, thereby reducing the no-load loss of the entire power supply system. For example, a high-efficiency linear regulated power supply or a switching regulated power supply is used as an auxiliary power supply, and the output power of the auxiliary power supply is reduced in standby. At the same time, by reasonably designing the circuit structure of the auxiliary power supply, the number of unnecessary components and power consumption can be reduced.
In low-power standby mode, the switching power supply can effectively reduce no-load losses and improve energy efficiency by optimizing switching frequency, using energy-saving chips, optimizing transformer design, implementing intelligent control strategies, optimizing auxiliary power circuits and other comprehensive applications of energy-saving technologies. This meets the energy-saving performance requirements of modern electronic equipment and provides strong technical support for achieving green and environmentally friendly power supply.
