Resonant converter

Abstract

The invention discloses a resonant converter. The resonant converter comprises a rectification bridge, a bus capacitor, a switch unit, a resonance network, a control unit, a shunting unit and a compensation signal generation unit. A positive output terminal of the rectification bridge is connected to one end of the bus capacitor. An input side of the switch unit is connected in parallel to the bus capacitor. An output terminal of the switch unit is connected to a positive input terminal of the resonance network. A negative input terminal of the resonance network is connected to a negative output terminal of the rectification bridge. The shunting unit carries out shunting on a positive resonant current and provides a path for a reversed resonant current. The control unit generates a switch tube driving control signal according to a compensation signal and a sampling signal representing a resonant converter output parameter. A compensation signal indicates the control unit to raise a work frequency of a rectification bridge input voltage zero crossing point position and reduce a work frequency of rectification bridge input voltage peak and valley value positions. The compensation signal generation unit adjusts the compensation signal according to changes of resonant converter output power or a rectification bridge input voltage. In the invention, a PF value of the resonant converter is increased.

Description

technical field [0001] The present invention relates to the technical field of power electronics, and more specifically, relates to a resonant converter. Background technique [0002] Compared with the traditional PWM converter, the resonant converter has smaller switching loss, so it has been widely used. Specifically: the resonant converter uses the resonant circuit as the basic conversion unit. When the circuit resonates, the current or voltage periodically crosses zero, so that the switching device is turned on or off under the condition of zero voltage or zero current, so as to realize soft switching. , to achieve the purpose of reducing switching losses. [0003] The PFC (Power Factor Correction, power factor correction) technology of the resonant converter is a hot research topic in the field of power electronics technology. The lower the PF (Power Factor, power factor) value of the resonant converter will increase the loss of the power grid. In the prior art, in o...

AI Technical Summary

Problems solved by technology

In the prior art, in order to improve the PF value of the resonant converter, it is often designed as a two-stage structure, the front stage is a PFC circuit, and the rear stage is a resonant conversion circuit. However, the design of the two-stage structure is complicated and the cost is high, so It is necessary to design a resonant converter with a single-stage structure and high PF value

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