Push-pull switching power supply topological structure

Abstract

The invention provides a push-pull switching power supply topological structure. The problem that energy of magnetic inductance in a transformer must be maintained on a secondary side when a traditional push-pull switching power supply is in dead time is solved. To maintain the energy of the magnetic inductance, a follow current conduction circuit must be formed on the secondary side of the transformer. For a push-pull circuit, two rectifier diodes are usually used to achieve the purpose, but the premise to ensure the reliable conduction of the diodes is that a load large enough must be available to generate a forward current that can be sufficiently reliably conducted. In addition, in an instant when an inverter switch tube of the push-pull circuit, a very high voltage spike is generateddue to the leakage inductance of the transformer, and a switching tube buffer circuit is usually used to solve the problem. According to the push-pull switching power supply topological structure, a magnetic inductance magnetic inductance circuit is added on a primary side, to maintain the energy of the magnetic inductance on the primary side, so that the voltage spike can be generated in an instant of switching tube turn-off, and the burden on the buffer circuit is reduced.

Description

technical field [0001] The invention belongs to the technical field of power electronics, and in particular relates to a topological structure of a push-pull switching power supply circuit. Background technique [0002] In the field of inverters, especially automotive inverters, due to its simple circuit, fewer power tubes, and less PCB space, push-pull circuit applications are widely used. But the push-pull selected power tube requires twice the input voltage characteristics, which is perfect for low-voltage and high-current point circuits, and has become the first choice for inverter power supply engineers. In the push-pull circuit, there is a center tap on the primary side of the transformer. The center tap is connected to the DC voltage source, and forms two sets of circuits with the two switch tubes respectively. By controlling the switch tubes to conduct alternately, the voltage of the DC voltage source can be adjusted. Inversion to produce an alternating positive and...

AI Technical Summary

Problems solved by technology

However, the principle of the commonly used passive buffer network is mostly to use resistance to consume the energy of the leakage inductance, which will generate a lot of resistance heat in a short time, and there are certain requirements for the power of the resistance

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