A Symmetrical Half-Bridge Resonant Open-loop DC Proportional Converter

Abstract

The application discloses a symmetrical half-bridge resonant open-loop DC proportional converter, including: a high-frequency pulse width controller and a high-frequency gate driver, and the output terminal of the high-frequency pulse width controller is connected to the input of the high-frequency gate driver The high-frequency pulse width controller is used to input control signals to the high-frequency gate driver, the output terminal of the high-frequency gate driver is connected to the primary side of the isolation drive transformer, and the high-frequency gate driver is used to enhance the current driving capability of the control signal ; The secondary end of the isolation drive transformer is respectively connected to the control end of the symmetrical half-bridge switching circuit and the control end of the high-frequency synchronous rectification filter circuit, and the isolation drive transformer is used to drive half of the symmetrical half-bridge switching circuit according to the enhanced control signal The bridge transistor and the full-bridge synchronous rectification transistor in the high-frequency synchronous rectification filter circuit are turned on or off. Through the technical solution in this application, the topology of the circuit is optimized, so that the converter responds quickly to the load and has high stability.

Description

technical field [0001] The present application relates to the technical field of DC conversion, in particular, to a symmetrical half-bridge resonant open-loop DC proportional converter. Background technique [0002] With the development of power semiconductor devices, topological circuits, and switching power supply controllers, the technical indicators of switching power supplies such as power density, reliability, efficiency, stability, and load response capability have also been continuously improved. [0003] The voltage regulation method of switching power supply is generally through the negative feedback compensation network to adjust the switching control pulse to achieve the purpose of output voltage stability. By sampling one or two variables such as output voltage, input voltage, input current or output current, and comparing the error with the control reference, it can be divided into current control loop, voltage control loop or double loop according to the diffe...

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Problems solved by technology

[0004] In the existing technology, these voltage stabilization methods are all closed-loop feedback, which are selected according to the voltage regulation accuracy, source characteristics, load characteristics, and the response speed of the feedback loop. The voltage regulation accuracy is high, but due to the isolation between the primary and secondary stages The sampling delay and the nonlinearity of the compensation network, the response speed of the feedback loop is slow, the stability is poor, and the feedback loop with excellent adjustment parameters needs dozens of switching cycles to adjust a load mutation. The road is also more prone to self-oscillation phenomenon

This is because the voltage regulation accuracy is proportional to the DC gain of the feedback loop, the load response adjustment speed of the power supply is proportional to the AC gain of the feedback loop, and too high gain is more likely to cause self-oscillation

, therefore, it is necessary to balance various indicators such as voltage regulation accuracy, load characteristics, and stability, and it is extremely complicated to optimize the feedback loop.

[0005] In addition, the switching power supply operating in closed-loop feedback mode controls the energy delivered to the secondary by adjusting the conduction pulse width, phase relationship or operating frequency of the transistor according to the feedback signal, thereby realizing the regulation of the output voltage. In such an operating mode, The transmission power of the transformer in the switching power supply does not reach the maximum, resulting in a waste of equipment capacity

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