Double-tube voltage conversion circuit

Abstract

The invention discloses a double-tube voltage conversion circuit which comprises a flyback module, a forward module, a primary side module, a secondary side module and a transformer module. The flyback module, the forward module, the primary side module, the secondary side module and the transformer module are completely independent from one another, electrical isolation among multiple modules is achieved through the transformer module, the stability of the voltage conversion circuit is improved, and particularly, the circuit is simple, cost is low, reliability is high, and a driving circuit is simple; meanwhile, the primary side module and the secondary side module are respectively provided with a corresponding primary side switch unit and a secondary side switch unit, through the two switch units, when the voltage conversion circuit breaks down, quick response of protection can be achieved, the voltage conversion circuit is effectively isolated from the voltage input side or the voltage output side, and the voltage conversion circuit is protected. Therefore, the safety of the voltage conversion circuit is improved, the safety of equipment connected with a fault device is also improved, and the predicted impact resistance of the voltage margin when the voltage conversion circuit is used in parallel or in series is improved.

Description

Technical Field

[0001] The invention relates to the technical field of power electronic converters, in particular to a dual-tube voltage conversion circuit. Background Art

[0002] With the rapid development of industrial production, high-power, high-gain converters are playing an increasingly important role in situations where power conversion is required. Dual-tube voltage conversion usually refers to the use of two field-effect transistors to control the voltage level in the circuit to achieve conversion from one voltage level to another. However, the existing voltage conversion circuit has poor stability and the inductance remains unchanged, which makes the circuit's power conversion efficiency low under certain working conditions. Therefore, we propose a dual-tube voltage conversion circuit to solve the above-mentioned problems. Summary of the invention

[0003] The object of the present invention is to provide a dual-transistor voltage conversion circuit to solve the problems raised in the above background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A dual-tube voltage conversion circuit, comprising: a flyback module, a forward module, a primary module, a secondary module and a transformer module, wherein the flyback module, the forward module, the primary module and the secondary module are all connected to the transformer module; the transformer module comprises a transformer, a first switch tube, a first inductor unit and a DC isolation unit, wherein the transformer is respectively connected to the first switch tube, the first inductor unit and the DC isolation unit, and the flyback module comprises a dual-tube flyback transformer body circuit with an active switch tube; the forward module comprises a first voltage source, a second voltage source, a third voltage source, a fourth voltage source, a fifth voltage source, a first capacitor, a second capacitor , a second switch tube, a third switch tube, a first diode, a second diode, a third diode, a fourth diode, a second inductor unit and a load; the primary module includes a primary switch unit, a primary transformer unit, a primary equalizing resistor unit and a primary control unit; the primary switch unit is connected to the voltage input side, the primary transformer unit is connected to the primary switch, and the primary equalizing unit is associated with the primary transformer unit; the secondary module includes a secondary transformer unit, a secondary switch unit and a secondary control unit; the secondary transformer unit is connected to the transformer module, and the secondary switch unit is respectively connected to the secondary transformer unit and the voltage output side.

[0006] As a further solution of the present invention: the transformer is used to perform voltage conversion on the input voltage obtained by the flyback module, the forward module, the primary module and the secondary module of the power input to obtain an output voltage; the first switch tube is used to switch the turns ratio of the transformer according to the input voltage and the output voltage; the inductor unit is used to provide a corresponding inductance when the first switch tube switches the turns ratio, so as to adjust the power conversion efficiency of the flyback module, the forward module, the primary module and the secondary module; the DC isolation unit is used to isolate the DC voltage of the secondary side of the transformer and output the AC voltage of the secondary side of the transformer to the secondary side module.

[0007] As a further solution of the present invention: the inductor unit includes a first inductor, a second inductor, a third inductor and a fourth inductor, the first end of the first inductor is connected to the first switching tube, the second end of the first inductor is connected to the first end of the primary side of the transformer, the first end of the second inductor is connected to the first switching tube, the second end of the second inductor is connected to the second end of the primary side of the transformer, the first end of the third inductor is connected to the first switching tube, the second end of the third inductor is connected to the first end of the secondary side of the transformer, the first end of the fourth inductor is connected to the first switching tube, the second end of the fourth inductor is connected to the second end of the secondary side of the transformer, and the third end of the primary side of the transformer is connected to the primary module, wherein the first inductor is greater than the second inductor, and the third inductor is greater than the fourth inductor.

[0008] As a further solution of the present invention: the main circuit of the dual-tube flyback transformer includes two bridge arms, and the bridge arms are composed of an active switching tube and a diode connected in series. The two connecting terminals of the primary winding of the transformer are respectively connected to the middle point between the active switching tube and the diode in one bridge arm, and the secondary winding of the transformer serves as the output end of the flyback module.

[0009] As a further solution of the present invention: the positive electrode of the first capacitor is connected to the drain of the second switch tube and the cathode of the second diode respectively; the negative electrode of the first capacitor is connected to the source of the third switch tube and the anode of the first diode respectively; the negative electrode of the first voltage source is connected to the source of the second switch tube, and its positive electrode is connected to the negative electrode of the third voltage source and the positive electrode of the fourth voltage source respectively; the negative electrode of the fourth voltage source is connected to the cathode of the first diode; the positive electrode of the third voltage source is connected to the same-name end of the primary module; the positive electrode of the fifth voltage source is connected to the anode of the second diode, and its negative electrode is connected to the negative electrode of the second voltage source and the opposite-name end of the primary module respectively; the same-name end of the secondary module is connected to the anode of the third diode, and its opposite-name end is connected to the anode of the fourth diode, the negative electrode of the second capacitor and one end of the load respectively; the cathode of the third diode is connected to the cathode of the fourth diode and one end of the second inductor unit respectively; the other end of the second inductor unit is connected to the positive electrode of the second capacitor and the other end of the load respectively.

[0010] As a further solution of the present invention: the primary switch unit is connected to the voltage input side, and is used to input the first DC voltage transmitted from the voltage input side into the voltage conversion circuit, or to realize the isolation of the voltage conversion circuit from the voltage input side; the primary transformer unit is connected to the primary switch, and is used to convert the first DC voltage into a first AC voltage; the primary voltage balancing unit is associated with the primary transformer unit, and is used to perform corresponding voltage balancing protection on the primary module according to the changing state of the first DC voltage; the primary control unit is used to control the on and off of the primary switch unit, control the voltage conversion of the primary transformer unit, and control the primary voltage balancing unit to perform voltage balancing protection.

[0011] As a further solution of the present invention: the secondary side transformer unit is connected to the transformer module, and is used to convert the second AC voltage into a second DC voltage; the secondary side switch unit is respectively connected to the secondary side transformer unit and the voltage output side, and is used to output the second DC voltage to the voltage output side, or to achieve isolation between the voltage conversion circuit and the voltage output side; the secondary side control unit is used to control the voltage conversion of the secondary side transformer unit and the on and off of the secondary side switch unit.

[0012] As a further solution of the present invention: the primary switch unit also includes a mechanical switch sub-unit and a primary static sub-unit.

[0013] As a further solution of the present invention: the mechanical switch subunit is respectively connected to the voltage input side, the primary static switch subunit and the primary control unit; the primary static switch subunit is respectively connected to the voltage input side, the primary transformer unit and the primary control unit.

[0014] As a further solution of the present invention: the mechanical switch sub-unit and the primary static switch sub-unit cooperate with each other to input the first DC voltage to the voltage conversion circuit or to isolate the voltage conversion circuit from the voltage input side under the control of the primary control unit.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] In the dual-tube voltage conversion circuit, the flyback module, the forward module, the primary module, the secondary module and the transformer module are completely independent of each other, and electrical isolation between the multiple modules is achieved through the transformer module, thereby improving the stability of the voltage conversion circuit. Specifically, the circuit is simple, the cost is low, the reliability is high, and the driving circuit is simple. At the same time, corresponding primary switch units and secondary switch units are respectively arranged in the primary module and the secondary module. Through the two switch units, a rapid response of protection can be achieved when a fault occurs in the voltage conversion circuit, and the voltage conversion circuit can be effectively isolated from the voltage input side or the voltage output side, thereby improving the safety of the voltage conversion circuit and also providing The safety of the equipment connected to the fault device is improved, so that the voltage margin predicted impact resistance of the voltage conversion circuit when used in parallel or series is improved, and it is also convenient for the voltage conversion circuit to be bypassed through the switch unit in the event of a fault, thereby automatically exiting the parallel or series structure; by setting the transformer module, the first switch unit can be switched according to the input voltage and the output voltage to switch the turns ratio of the transformer, and the inductance connected to the inductor unit is adjusted at the same time, so that the flyback module, the forward module, the primary side module, and the secondary side module can all meet the corresponding switch tube soft switching requirements, ensuring that the voltage conversion circuit can maintain a better power conversion efficiency under different working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the dual-tube voltage conversion circuit of the present invention. DETAILED DESCRIPTION

[0018] In one embodiment, Figure 1 As shown, a dual-tube voltage conversion circuit includes: a flyback module, a forward module, a primary module, a secondary module and a transformer module, wherein the flyback module, the forward module, the primary module and the secondary module are all connected to the transformer module; the transformer module includes a transformer, a first switch tube, a first inductor unit and a DC isolation unit, wherein the transformer is respectively connected to the first switch tube, the first inductor unit and the DC isolation unit, and the flyback module includes a dual-tube flyback transformer body circuit with an active switch tube; the forward module includes a first voltage source, a second voltage source, a third voltage source, a fourth voltage source, a fifth voltage source, a first capacitor, a second capacitor, and a third capacitor. The primary module includes a primary switch unit, a primary transformer unit, a primary voltage balancing resistor unit and a primary control unit; the primary switch unit is connected to the voltage input side, the primary transformer unit is connected to the primary switch, and the primary voltage balancing unit is associated with the primary transformer unit; the secondary module includes a secondary transformer unit, a secondary switch unit and a secondary control unit; the secondary transformer unit is connected to the transformer module, and the secondary switch unit is respectively connected to the secondary transformer unit and the voltage output side;

[0019] A transformer, used for converting the input voltage of the power input, obtained through the flyback module, the forward module, the primary module, and the secondary module, to obtain an output voltage; a first switch tube, used for switching the turns ratio of the transformer according to the input voltage and the output voltage; an inductor unit, used for providing a corresponding inductance when the first switch tube switches the turns ratio, so as to adjust the power conversion efficiency of the flyback module, the forward module, the primary module, and the secondary module; a DC isolation unit, used for isolating the DC voltage of the secondary side of the transformer, and outputting the AC voltage of the secondary side of the transformer to the secondary side module;

[0020] In the specific implementation, in order to ensure that different input and output conditions can meet the inductance requirements of the switch tube for efficient operation, this embodiment improves the transformer module. Specifically, the first switch unit is switched according to the input voltage and the output voltage to switch the turns ratio of the transformer, and the inductance connected to the inductor unit is adjusted at the same time, so that the flyback module, the forward module, the primary side module, and the secondary side module can all meet the corresponding switch tube soft switching requirements, ensuring that the voltage conversion circuit can maintain a relatively good power conversion efficiency under different working conditions;

[0021] It can be seen that the first switch tube is switched according to the input voltage and the output voltage to switch the turns ratio of the transformer, and the inductance connected to the first inductor unit is adjusted at the same time, so that the flyback module, the forward module, the primary module, and the secondary module can all meet the corresponding switch tube soft switching requirements. In this way, the transformer turns ratio is switched according to different input and output states to adjust the inductance, so as to improve the control effect of the circuit switch and improve the power conversion efficiency of the voltage conversion circuit under a wide range of conditions.

[0022] The inductor unit includes a first inductor, a second inductor, a third inductor and a fourth inductor, wherein a first end of the first inductor is connected to a first switch tube, a second end of the first inductor is connected to a first end of a primary side of a transformer, a first end of the second inductor is connected to the first switch tube, a second end of the second inductor is connected to a second end of a primary side of a transformer, a first end of the third inductor is connected to the first switch tube, a second end of the third inductor is connected to a first end of a secondary side of a transformer, a first end of the fourth inductor is connected to the first switch tube, a second end of the fourth inductor is connected to a second end of a secondary side of a transformer, and a third end of a primary side of a transformer is connected to a primary side module, wherein the first inductor is greater than the second inductor, and the third inductor is greater than the fourth inductor;

[0023] The main circuit of the double-tube flyback transformer includes two bridge arms, each of which is composed of an active switch tube and a diode connected in series. The two connection terminals of the primary winding of the transformer are each connected to the middle point between the active switch tube and the diode in one bridge arm, and the secondary winding of the transformer serves as the output end of the flyback module.

[0024] The positive electrode of the first capacitor is connected to the drain of the second switch tube and the cathode of the second diode respectively; the negative electrode of the first capacitor is connected to the source of the third switch tube and the anode of the first diode respectively; the negative electrode of the first voltage source is connected to the source of the second switch tube, and its positive electrode is connected to the negative electrode of the third voltage source and the positive electrode of the fourth voltage source respectively; the negative electrode of the fourth voltage source is connected to the cathode of the first diode; the positive electrode of the third voltage source is connected to the same-name end of the primary module; the positive electrode of the fifth voltage source is connected to the anode of the second diode, and its negative electrode is connected to the negative electrode of the second voltage source and the opposite-name end of the primary module respectively; the same-name end of the secondary module is connected to the anode of the third diode, and its opposite-name end is connected to the anode of the fourth diode, the negative electrode of the second capacitor and one end of the load respectively; the cathode of the third diode is connected to the cathode of the fourth diode and one end of the second inductor unit respectively; the other end of the second inductor unit is connected to the positive electrode of the second capacitor and the other end of the load respectively;

[0025] A primary switch unit, connected to the voltage input side, for inputting the first DC voltage transmitted from the voltage input side into the voltage conversion circuit, or realizing isolation of the voltage conversion circuit from the voltage input side; a primary transformer unit, connected to the primary switch, for converting the first DC voltage into a first AC voltage; a primary voltage balancing unit, associated with the primary transformer unit, for performing corresponding voltage balancing protection on the primary module according to the change state of the first DC voltage; a primary control unit, for controlling the on and off of the primary switch unit, controlling the voltage conversion of the primary transformer unit, and controlling the primary voltage balancing unit to perform voltage balancing protection;

[0026] A secondary side transformer unit is connected to the transformer module and is used to convert the second AC voltage into a second DC voltage; a secondary side switch unit is connected to the secondary side transformer unit and the voltage output side, respectively, and is used to output the second DC voltage to the voltage output side, or to isolate the voltage conversion circuit from the voltage output side; a secondary side control unit is used to control the voltage conversion of the secondary side transformer unit and the on-off of the secondary side switch unit;

[0027] The primary switch unit also includes a mechanical switch subunit and a primary static subunit;

[0028] The mechanical switch subunit is connected to the voltage input side, the primary static switch subunit and the primary control unit respectively; the primary static switch subunit is connected to the voltage input side, the primary transformer unit and the primary control unit respectively;

[0029] The mechanical switch subunit and the primary static switch subunit cooperate with each other to input the first DC voltage to the voltage conversion circuit or to isolate the voltage conversion circuit from the voltage input side under the control of the primary control unit;

[0030] In the present invention, the flyback module, the forward module, the primary module, the secondary module and the transformer module are completely independent of each other, and electrical isolation between the multiple modules is achieved through the transformer module, thereby improving the stability of the voltage conversion circuit. Specifically, the circuit is simple, the cost is low, the reliability is high, and the driving circuit is simple. At the same time, corresponding primary switch units and secondary switch units are respectively arranged in the primary module and the secondary module. Through the two switch units, when a fault occurs in the voltage conversion circuit, a rapid response of protection can be achieved, and the voltage conversion circuit can be effectively isolated from the voltage input side or the voltage output side, thereby improving the safety of the voltage conversion circuit, and also improving the safety of the equipment connected to the fault device, so as to improve the voltage margin predicted impact resistance of the voltage conversion circuit when used in parallel or series, and also facilitate the voltage conversion circuit to be bypassed through the switch unit when a fault occurs, thereby automatically exiting the parallel or series structure.

[0031] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A dual-tube voltage conversion circuit, characterized in that: include: A flyback module, a forward module, a primary module, a secondary module and a transformer module, wherein the flyback module, the forward module, the primary module and the secondary module are all connected to the transformer module; the transformer module includes a transformer, a first switch tube, a first inductor unit and a DC isolation unit, and the transformer is respectively connected to the first switch tube, the first inductor unit and the DC isolation unit; the flyback module includes a double-tube flyback transformer body circuit with an active switch tube; the forward module includes a first voltage source, a second voltage source, a third voltage source, a fourth voltage source, a fifth voltage source, a first capacitor, a second capacitor, a second switch tube, A third switch tube, a first diode, a second diode, a third diode, a fourth diode, a second inductor unit and a load; the primary module includes a primary switch unit, a primary transformer unit, a primary equalizing resistor unit and a primary control unit; the primary switch unit is connected to the voltage input side, the primary transformer unit is connected to the primary switch, and the primary equalizing unit is associated with the primary transformer unit; the secondary module includes a secondary transformer unit, a secondary switch unit and a secondary control unit; the secondary transformer unit is connected to the transformer module, and the secondary switch unit is respectively connected to the secondary transformer unit and the voltage output side.

2. A dual-tube voltage conversion circuit according to claim 1, characterized in that: The transformer is used to convert the input voltage of the power input obtained through the flyback module, the forward module, the primary module, and the secondary module to obtain an output voltage; the first switch tube is used to switch the turns ratio of the transformer according to the input voltage and the output voltage; the inductor unit is used to provide a corresponding inductance when the first switch tube switches the turns ratio to adjust the power conversion efficiency of the flyback module, the forward module, the primary module, and the secondary module; the DC isolation unit is used to isolate the DC voltage of the secondary side of the transformer and output the AC voltage of the secondary side of the transformer to the secondary side module.

3. A dual-tube voltage conversion circuit according to claim 2, characterized in that: The inductor unit includes a first inductor, a second inductor, a third inductor and a fourth inductor, wherein a first end of the first inductor is connected to a first switching tube, a second end of the first inductor is connected to a first end of a primary side of a transformer, a first end of the second inductor is connected to the first switching tube, a second end of the second inductor is connected to a second end of a primary side of a transformer, a first end of the third inductor is connected to the first switching tube, a second end of the third inductor is connected to a first end of a secondary side of a transformer, a first end of the fourth inductor is connected to the first switching tube, a second end of the fourth inductor is connected to a second end of a secondary side of a transformer, and a third end of the primary side of the transformer is connected to a primary side module, wherein the first inductor is greater than the second inductor, and the third inductor is greater than the fourth inductor.

4. A dual-tube voltage conversion circuit according to claim 1, characterized in that: The main circuit of the dual-tube flyback transformer includes two bridge arms, each of which is composed of an active switch tube and a diode connected in series. The two connecting terminals of the primary winding of the transformer are respectively connected to the middle node between the active switch tube and the diode in one bridge arm, and the secondary winding of the transformer serves as the output end of the flyback module.

5. A dual-tube voltage conversion circuit according to claim 1, characterized in that: The positive electrode of the first capacitor is connected to the drain of the second switch tube and the cathode of the second diode respectively; the negative electrode of the first capacitor is connected to the source of the third switch tube and the anode of the first diode respectively; the negative electrode of the first voltage source is connected to the source of the second switch tube, and its positive electrode is connected to the negative electrode of the third voltage source and the positive electrode of the fourth voltage source respectively; the negative electrode of the fourth voltage source is connected to the cathode of the first diode; the positive electrode of the third voltage source is connected to the same-name end of the primary module; the positive electrode of the fifth voltage source is connected to the anode of the second diode, and its negative electrode is connected to the negative electrode of the second voltage source and the opposite-name end of the primary module respectively; the same-name end of the secondary module is connected to the anode of the third diode, and its opposite-name end is connected to the anode of the fourth diode, the negative electrode of the second capacitor and one end of the load respectively; the cathode of the third diode is connected to the cathode of the fourth diode and one end of the second inductor unit respectively; the other end of the second inductor unit is connected to the positive electrode of the second capacitor and the other end of the load respectively.

6. A dual-tube voltage conversion circuit according to claim 1, characterized in that: The primary switch unit is connected to the voltage input side, and is used to input the first DC voltage transmitted from the voltage input side into the voltage conversion circuit, or to isolate the voltage conversion circuit from the voltage input side; the primary transformer unit is connected to the primary switch, and is used to convert the first DC voltage into a first AC voltage; the primary voltage balancing unit is associated with the primary transformer unit, and is used to perform corresponding voltage balancing protection on the primary module according to the change state of the first DC voltage; the primary control unit is used to control the on and off of the primary switch unit, control the voltage conversion of the primary transformer unit, and control the primary voltage balancing unit to perform voltage balancing protection.

7. A dual-transistor voltage conversion circuit according to claim 1, characterized in that: The secondary side transformer unit is connected to the transformer module and is used to convert the second AC voltage into a second DC voltage; the secondary side switch unit is respectively connected to the secondary side transformer unit and the voltage output side and is used to output the second DC voltage to the voltage output side, or to achieve isolation between the voltage conversion circuit and the voltage output side; the secondary side control unit is used to control the voltage conversion of the secondary side transformer unit and the on and off of the secondary side switch unit.

8. A dual-transistor voltage conversion circuit according to claim 1, characterized in that: The primary switch unit further comprises a mechanical switch subunit and a primary static subunit.

9. A dual-tube voltage conversion circuit according to claim 8, characterized in that: The mechanical switch subunit is connected to the voltage input side, the primary static switch subunit and the primary control unit respectively; the primary static switch subunit is connected to the voltage input side, the primary transformer unit and the primary control unit respectively.

10. A dual-transistor voltage conversion circuit according to claim 9, characterized in that: The mechanical switch subunit and the primary static switch subunit cooperate with each other to input the first DC voltage to the voltage conversion circuit or to isolate the voltage conversion circuit from the voltage input side under the control of the primary control unit.

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