Resonant converter and synchronous rectification converter circuit thereof

Patent metadata

Field	Value
Publication number	US-9780687-B2
Application number	US-201514924989-A
Country	US
Kind code	B2
Filing date	Oct 28, 2015
Priority date	Apr 16, 2014
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

The present invention provides a synchronous rectification converter circuit, including three transformer secondary-windings, three current transformer, a synchronous rectification switching unit, a diode rectification unit, and a control unit. Each of three current transformers includes a primary-winding and secondary-winding. The three transformer secondary-windings and the three current transformer primary-windings are alternately connected in series to form a first triangular structure. Three vertices of the first triangular structure are connected to the synchronous rectification switching unit. The three current transformer secondary-windings are connected in series to form a second triangular structure. Three vertices of the second triangular structure are connected to the diode rectification unit. The diode rectification unit is connected to the control unit and the synchronous rectification switching unit is connected to the control unit. The present invention achieves a purpose of precisely controlling the on-off state of the synchronous rectification circuit.

First claim

What is claimed is:

1. A synchronous rectification converter circuit, which is applied to a resonant converter, wherein the synchronous rectification converter circuit comprises a first transformer, a second transformer, a third transformer, a first current transformer, a second current transformer, a third current transformer, a synchronous rectification switching unit, a diode rectification unit and control unit;
the first transformer includes a first transformer secondary-side winding; the second transformer includes a second transformer secondary-side winding; the third transformer includes a third transformer secondary-side winding;
the first current transformer include a first current transformer primary-side winding and a first current transformer secondary-side winding; the second current transformer include a second current transformer primary-side winding and a second current transformer secondary-side winding; the third current transformer include a third current transformer primary-side winding and a third current transformer secondary-side winding;
the first transformer secondary-side winding and the first current transformer primary-side winding are in series to form a first branch; the second transformer secondary-side winding and the second current transformer primary-side winding are in series to form a second branch; and the third transformer secondary-side winding and the third current transformer primary-side winding are in series to form a third branch; wherein the first branch, the second branch and the third branch are in series to form a first triangle structure;
the first current transformer secondary-side winding, the second current transformer secondary-side winding and the third current transformer secondary-side winding are in series to form a second triangle structure;
the synchronous rectification switching unit includes a first node, a second node and a third node; the three vertices of the first triangle structure are respectively connected to the first node, the second node and the third node;
the diode rectification unit includes a fourth node, a fifth node and a sixth node; the three vertices of the second triangle structure are respectively connected to the fourth node, the fifth node and the sixth node;
the control unit includes a diode voltage sampling circuit and a controller; the diode rectification unit is connected to the diode voltage sampling circuit; the diode voltage sampling circuit is connected to the controller; the controller is connected to the synchronous rectification switching unit;
the diode voltage sampling circuit detects voltage of a diode included in the diode rectification unit to acquire a diode voltage value and sends the diode voltage value to the controller;
the controller determines whether a current flows through a switching transistor in the synchronous rectification switch unit, which is corresponding to the diode included in the diode rectification unit; wherein when a current flows through the switching transistor, the controller sends a control signal to the switching transistor to make the switching transistor open.

2. The synchronous rectification converter circuit according to claim 1 , the control unit also includes a resistance;
the diode rectification unit includes a first to third groups of diodes;
the first to third groups of diodes are connected in parallel with the ends of the resistance;
the first group of diodes includes two diodes and a fourth node between the two diodes; the two diodes of the first group diodes are connected in series;
the second group of diodes includes two diodes and a fifth node between the two diodes; the two diodes of the second group diodes are connected in series;
the third group of diodes includes two diodes and a sixth node between the two diodes; the two diodes of the third group diodes are connected in series.

3. The synchronous rectification converter circuit according to claim 2 , wherein:
a dotted terminal of the first transformer secondary-side winding is connected to a dotted terminal of the first current transformer primary-side winding, an undotted terminal of the first transformer secondary-side winding is connected to an undotted terminal of the second current transformer primary-side winding, and the undotted terminal of the first transformer secondary-side winding is further connected to the second node of the synchronous rectification switching unit;
a dotted terminal of the second transformer secondary-side winding is connected to a dotted terminal of the second current transformer primary-side winding; an undotted terminal of second transformer secondary-side winding is connected to an undotted terminal of the third current transformer primary-side winding; and the undotted terminal of the second transformer secondary-side winding is further connected to the third node of the synchronous rectification switching unit;
a dotted terminal of the third transformer secondary-side winding is connected to a dotted terminal of third current transformer primary-side winding; an undotted terminal of the third transformer secondary-side winding is connected to an undotted terminal of first current transformer primary-side winding; and the undotted terminal of third transformer secondary-side winding is further connected to the first node of the synchronous rectification switching unit;
a dotted terminal of the first current transformer secondary-side winding is connected to an undotted terminal of the third current transformer secondary-side winding; the dotted terminal of first current transformer secondary-side winding is further connected to the fourth node of the first group of diodes; an undotted terminal of the first current transformer secondary-side winding is connected to a dotted terminal of the second current transformer secondary-side winding; and the undotted terminal of the first current transformer secondary-side winding is further connected to the fifth node of the second group of diodes; and
an undotted terminal of the second current transformer secondary-side winding is connected to a dotted terminal of the third current transformer secondary-side winding; and the undotted terminal of the second current transformer secondary-side winding is further connected to the sixth node of the third group of diodes.

4. The synchronous rectification converter circuit according to claim 2 , wherein the first group of diodes comprises a first diode and a second diode; the second group of diodes comprises a third diode and a fourth diode; the third group of diodes comprises a fifth diode and a sixth diode; a positive electrode of the first diode is connected to a negative electrode of the second diode; the positive electrode of the first diode is further connected to the dotted terminal of the first current transformer secondary-side winding; a negative electrode of the first diode is connected to a first end of the resistor; a positive electrode of the second diode is connected to a second end of the resistor; a positive electrode of the third diode is connected to a negative electrode of the fourth diode; the positive electrode of the third diode is further connected to the dotted terminal of the second current transformer secondary-side winding; a negative electrode of the third diode is connected to the first end of the resistor; a positive electrode of the fourth diode is connected to the second end of the resistor; a positive electrode of the fifth diode is connected to a negative electrode of the sixth diode; the positive electrode of the fifth diode is further connected to the dotted terminal of the third current transformer secondary-side winding; a negative electrode of the fifth diode is connected to the first end of the resistor; and a positive electrode of the sixth diode is connected to the second end

Assignees

• Huawei Tech Co Ltd

Inventors

• Chen Wenbin
• Zhou Kui

Classifications

• H02M3/33592 Primary

  having a synchronous rectifier circuit or a synchronous freewheeling circuit at the secondary side of an isolation transformer · CPC title

• H02M7/06 Primary

  using discharge tubes without control electrode or semiconductor devices without control electrode · CPC title

• Y02B70/1475

  Cross-Sectional Technologies · mapped topic

• H02M2007/2195

  Electricity · mapped topic

• Y02B70/1433

  Cross-Sectional Technologies · mapped topic