How to improve the efficiency of switching power supply
The power consumption of a switching power supply consists of fixed losses due to parasitic resistances of semiconductor switches, magnetic components, wiring, etc., and switching losses during switching operations. Fixed losses are mainly dependent on the characteristics of the components themselves, and therefore need to be suppressed through improvements in component technology. In the case of magnetic components, low-loss winding methods that take into account both the skin effect and the neighbouring wire effect have been studied for a long time. In order to reduce switching losses caused by switching surges originating from the leakage inductance of transformers, new circuit technologies such as buffer circuits with surge energy regeneration have been developed. The following are circuits and system methods for improving the efficiency of switching power supplies.
(1 ) ZVS (Zero Voltage Switching), ZCS (Zero Current Switching), and other methods that use resonant switching to reduce switching losses.
(2 ) Reduction of switching losses by using Edge ResONance represented by active clamping circuits.
(3) Fixed losses are reduced by extending the on-time of the switching element to suppress the peak current.
(4) Reducing fixed losses by improving synchronous rectification circuits for low-voltage, high-current applications.
(5) Reduction of fixed loss by utilising the parallel structure of the converter.
The first method is extremely effective in reducing switching losses, but the problem is that the fixed losses due to peak current and peak voltage will increase. The second method is developed to solve the problem of active snubber (Active Snubber), is an extremely practical ZVS method; however, by the light load conditions of the However, the efficiency degradation caused by the reactive current under light load conditions is one of its major drawbacks. In the third method, the use of TapInductor (TapInductor) is more effective, it can cope with the leakage current caused by the leakage current. The third method, the TapInductor method, is more effective and can cope with the surge phenomenon caused by leakage inductance. Regarding the fourth method, the two-stage structure is one of the ways to achieve efficient operation of synchronous rectifier circuits. The two-stage structure is one of the ways to achieve efficient operation of a synchronous rectifier circuit, using a fixed time ratio close to 0.5 and output voltage control by the converter in the front stage. It goes against the conventional wisdom that a two-stage structure will Lead to a decline in efficiency" this traditional mode of thinking, in the low-voltage high-current occasions is very effective. As for the fifth method, either the entire converter circuit can be paralleled, or like a current multiplier. As for the fifth method, either the whole converter circuit can be connected in parallel, or a part of it can be connected in parallel as in the case of the Current Doubler. The following is a brief description of the efficiency gains achieved by parallel operation of the converter. The following is a brief description of the efficiency gains achieved using the parallel operation of the converter.
