TWI697180B - Power conversion device - Google Patents

Abstract

The invention discloses a power conversion device, which includes a transformer, a first electronic switch, a second electronic switch, at least one balancing capacitor, at least one voltage stabilizing capacitor and a power supply circuit. The first electronic switch, the second electronic switch, the balancing capacitor and the voltage stabilizing capacitor are connected to the primary side of the transformer, and the secondary side of the transformer is connected to the power supply circuit. The primary side has a first end, a second end and a third end therebetween. The first electronic switch and the second electronic switch are respectively connected to the high voltage end and the low voltage end, and the voltage stabilizing capacitor is connected between the two voltage ends. One end of the balancing capacitor is connected to the third end, the other end is connected to the voltage stabilizing capacitor, or both the high-voltage end and the low-voltage end are connected at the same time, thereby balancing the voltage span between the first electronic switch and the second electronic switch and stabilizing the entire device.

Description

Power conversion device

The invention relates to a conversion device, and in particular to a power conversion device.

Since the internal components of most electronic equipment require a direct current (DC) voltage, a power supply is used to convert the alternating current (AC) voltage or DC voltage to a DC voltage to make the electronic equipment work properly. The power supply is divided into non-isolated power supply and isolated switching power supply. For safety and other performance considerations, most AC to DC and some DC to DC converters use isolated power supplies, including power transformers. There are many topologies for this type of converter. Examples of such isolated converter topologies include flyback, forward, approximate resonance (Quasi-Resonant), full bridge, and half bridge. -Bridge) and Push-Pull.

Taking a flyback power converter as an example, as shown in FIG. 1, the flyback power converter includes a first electronic switch 10, a second electronic switch 12, a controller 14, a transformer 16, a first The diode 18, a second diode 20, a voltage stabilizing capacitor 22, a third diode 24 and a load capacitor 26. There is a DC voltage drop between the high voltage terminal HV and the low voltage terminal LV. When the controller 14 turns on the first electronic switch 10 and the second electronic switch 12, the DC voltage drop stores energy in the primary side of the transformer 16 through the first electronic switch 10 and the second electronic switch 12, and the controller 14 turns off the first When an electronic switch 10 and a second electronic switch 12 are used, the transformer 16 uses the stored energy to provide the output voltage to the load capacitor 26 and the load 28 through the third diode 24. Since the DC voltage drop is usually a high voltage, the first electronic switch 10 and the second electronic switch 12 connected in series are used to withstand the high voltage. In addition, considering the voltage tolerance, the first electronic switch 10 and the second electronic switch 12 also use high-voltage transistors. However, there are limited semiconductor manufacturers on the market that can supply high-voltage transistors, and the parasitic capacitance of the high-voltage transistors varies according to different conditions of the semiconductor manufacturing process, resulting in the cross-voltage between the first electronic switch 10 and the second electronic switch 12 Not the same, making the entire circuit unstable.

Therefore, the present invention proposes a power conversion device in order to solve the above problems, so as to solve the problems caused by the conventional knowledge.

The main purpose of the present invention is to provide a power conversion device which is designed to balance voltage and the primary side of the transformer with an appropriate voltage across, so that without changing the internal structure of the first electronic switch and the second electronic switch, To balance the voltage across the first electronic switch and the second electronic switch to improve the stability of the power conversion device and make the component selection more flexible.

To achieve the above object, the present invention provides a power conversion device including a transformer, a first electronic switch, a second electronic switch, at least a first voltage stabilizing capacitor, at least a second voltage stabilizing capacitor, a balancing capacitor and a Power supply circuit. The transformer has a primary side and a secondary side. The primary side has a first winding, a second winding, a first end, a second end and a third end. The third end is located between the first end and the second end. One winding is located between the first end and the third end, the second winding is located between the third end and the second end, and the first winding and the second winding have energy. The first electronic switch is electrically connected between a high-voltage terminal and the second terminal, and the second electronic switch is electrically connected between a low-voltage terminal and the first terminal. The first voltage stabilizing capacitor and the second voltage stabilizing capacitor are electrically connected in series between the high voltage end and the low voltage end. One end of the balancing capacitor is electrically connected between the first voltage stabilizing capacitor and the second voltage stabilizing capacitor, and the other end is electrically connected to the third terminal. The power supply circuit is electrically connected to the secondary side and a load, generates a DC voltage between the high voltage end and the low voltage end, and when the first electronic switch and the second electronic switch are turned off, the transformer uses energy to provide the output voltage through the power supply circuit For the load, the first total voltage across the second winding and the first electronic switch is equal to the second total voltage across the balancing capacitor and the first regulator capacitor, and the third total voltage across the first winding and the second electronic switch is equal to the balancing capacitor The fourth total crossover voltage with the second voltage stabilizing capacitor, the sum of the first total crossover voltage and the fourth total crossover voltage is equal to the sum of the second total crossover voltage and the third total crossover voltage, the second total crossover voltage and the third total crossover voltage The sum of the cross voltages is equal to the DC voltage, and the cross voltages of the first voltage stabilizing capacitor, the second voltage stabilizing capacitor, the first winding and the second winding are balanced with each other to balance the cross voltages of the first electronic switch and the second electronic switch.

In an embodiment of the present invention, the cross voltage of the first voltage stabilizing capacitor is proportional to the cross voltage of the second winding, and the cross voltage of the second voltage stabilizing capacitor is proportional to the cross voltage of the first winding.

In an embodiment of the present invention, when the number of coils of the first winding and the second winding is the same, the capacitance values of the first voltage stabilizing capacitor and the second voltage stabilizing capacitor are the same.

In an embodiment of the present invention, the cross voltage of the first voltage stabilizing capacitor is inversely proportional to the cross voltage of the first winding, and the cross voltage of the second voltage stabilizing capacitor is inversely proportional to the cross voltage of the second winding.

In an embodiment of the invention, the secondary side has a fourth terminal and a fifth terminal. The power supply circuit includes a first diode and a power supply capacitor. The positive electrode of the first diode is electrically connected to the fourth end, and the negative electrode is electrically connected to the load. One end of the power supply capacitor is electrically connected to the load and the negative electrode of the first diode, and the other end is electrically connected to the load, a ground end and the fifth end. The transformer uses energy to provide an output voltage to the load through the first diode and the power supply capacitor.

In an embodiment of the invention, the power supply circuit further includes a second diode and an inductor. The positive electrode of the second diode is electrically connected to the ground terminal and the fifth terminal, and the negative electrode is electrically connected to the negative electrode of the first diode. One end of the inductor is electrically connected to the negative poles of the first diode and the second diode, and the other end is electrically connected to the power supply capacitor and the load. The transformer uses energy to provide an output voltage to the load through the second diode and the inductor.

In one embodiment of the present invention, when the DC voltage is generated and the first electronic switch and the second electronic switch are turned on, the DC voltage stores energy in the first winding and the second winding through the first electronic switch and the second electronic switch.

In an embodiment of the invention, the first electronic switch and the second electronic switch are gold-oxide half-field effect transistors.

In one embodiment of the present invention, the power conversion device further includes a first rectifying diode, the positive electrode of which is electrically connected to the first terminal and the second electronic switch, the negative electrode is electrically connected to the high voltage terminal, and the first rectifying diode The blocking surge is transmitted from the high voltage end to the primary side.

In one embodiment of the present invention, the power conversion device further includes a second rectifier diode, the positive electrode of which is electrically connected to the second terminal and the first electronic switch, the negative electrode is electrically connected to the low voltage terminal, and the second rectifier diode The blocking surge is transmitted from the low voltage end to the primary side.

The invention also provides a power conversion device including a transformer, a first electronic switch, a second electronic switch, a first balanced capacitor, a second balanced capacitor and a power supply circuit. The transformer has a primary side and a secondary side. The primary side has a first winding, a second winding, a first end, a second end and a third end. The third end is located between the first end and the second end. One winding is located between the first end and the third end, the second winding is located between the third end and the second end, and the first winding and the second winding have energy. The first electronic switch is electrically connected between a high-voltage terminal and the second terminal, the second electronic switch is electrically connected between a low-voltage terminal and the first terminal, and the first balancing capacitor is electrically connected to the third terminal and Between the high voltage terminal, the second balancing capacitor is electrically connected between the third terminal and the low voltage terminal. The power supply circuit is electrically connected to the secondary side and a load, generates a DC voltage between the high voltage end and the low voltage end, and when the first electronic switch and the second electronic switch are turned off, the transformer uses energy to provide the output voltage through the power supply circuit To the load, the first total voltage across the first electronic switch and the second winding is equal to the voltage across the first balancing capacitor, and the second total voltage across the second electronic switch and the first winding is equal to the voltage across the second balancing capacitor. The third total cross voltage of the second winding, the second balanced capacitor and the first electronic switch is equal to the fourth total cross voltage of the first winding, the first balanced capacitor and the second electronic switch, and the fourth total cross voltage is equal to the first balanced capacitor and The fifth total voltage across the second balancing capacitor, and the voltage across the first balancing capacitor, the second balancing capacitor, the first winding and the second winding are balanced with each other to balance the voltage across the first electronic switch and the second electronic switch.

In an embodiment of the invention, the power conversion device further includes at least one voltage stabilizing capacitor, which is electrically connected between the high voltage terminal and the low voltage terminal.

In an embodiment of the present invention, the voltage across the first balancing capacitor is proportional to the voltage across the second winding, and the voltage across the second balancing capacitor is proportional to the voltage across the first winding.

In an embodiment of the invention, when the number of coils of the first winding and the second winding is the same, the capacitance values of the first balancing capacitor and the second balancing capacitor are the same.

In an embodiment of the present invention, the voltage across the first balancing capacitor is inversely proportional to the voltage across the first winding, and the voltage across the second balancing capacitor is inversely proportional to the voltage across the second winding.

In an embodiment of the invention, the secondary side has a fourth end and a fifth end, and the power supply circuit includes a first diode and a power supply capacitor. The positive electrode of the first diode is electrically connected to the fourth end, and the negative electrode is electrically connected to the load. One end of the power supply capacitor is electrically connected to the load and the negative electrode of the first diode, and the other end is electrically connected to the load, a ground end and the fifth end. The transformer uses energy to provide an output voltage to the load through the first diode and the power supply capacitor.

In an embodiment of the invention, the power supply circuit further includes a second diode and an inductor. The positive electrode of the second diode is electrically connected to the ground terminal and the fifth terminal, and the negative electrode is electrically connected to the negative electrode of the first diode. One end of the inductor is electrically connected to the negative poles of the first diode and the second diode, and the other end is electrically connected to the power supply capacitor and the load. The transformer uses energy to provide an output voltage to the load through the second diode and the inductor.

In one embodiment of the present invention, when the DC voltage is generated and the first electronic switch and the second electronic switch are turned on, the DC voltage stores energy in the first winding and the second winding through the first electronic switch and the second electronic switch.

In one embodiment of the present invention, the first electronic switch and the second electronic switch are metal oxide half field effect transistors.

In one embodiment of the present invention, the power conversion device further includes a first rectifying diode, the positive electrode of which is electrically connected to the first terminal and the second electronic switch, the negative electrode is electrically connected to the high voltage terminal, and the first rectifying diode The blocking surge is transmitted from the high voltage end to the primary side.

In one embodiment of the present invention, the power conversion device further includes a second rectifier diode, the positive electrode of which is electrically connected to the second terminal and the first electronic switch, the negative electrode is electrically connected to the low voltage terminal, and the second rectifier diode The blocking surge is transmitted from the low voltage end to the primary side.

In order to make your reviewer have a better understanding and understanding of the structural features and achieved effects of the present invention, I would like to use the preferred embodiment drawings and detailed descriptions, the explanations are as follows:

The embodiments of the present invention will be further explained in the following with the related drawings. As much as possible, in the drawings and the description, the same reference numerals represent the same or similar components. In the drawings, the shape and thickness may be exaggerated for simplicity and convenience. It can be understood that elements that are not specifically shown in the drawings or described in the specification are in a form known to those of ordinary skill in the technical field. Those of ordinary skill in the art may make various changes and modifications according to the content of the present invention.

When an element is called "on", it can refer to the element directly on the other element, or there can be other elements in the two. Conversely, when an element is called "directly in" another element, it cannot have other elements in between. As used herein, the term "and/or" includes any combination of one or more of the associated items listed.

The description of "one embodiment" or "one embodiment" in the following refers to a specific element, structure or feature related to at least one embodiment. Therefore, multiple descriptions of "one embodiment" or "one embodiment" appearing in various places hereinafter do not refer to the same embodiment. Furthermore, specific components, structures and features in one or more embodiments may be combined in an appropriate manner.

Please refer to FIG. 2 and introduce the first embodiment of the power conversion device of the present invention. The power conversion device includes a transformer 30, a first electronic switch 32, a second electronic switch 34, at least a first voltage stabilizing capacitor 36, at least a second voltage stabilizing capacitor 38, a balancing capacitor 40, a power supply circuit 42, A first rectifier diode 44, a second rectifier diode 46 and a controller 48, wherein the first electronic switch 32 and the second electronic switch 34 take the metal oxide half field effect transistor as an example, but the invention does not Not limited to this, the number of the first voltage stabilizing capacitor 36 and the second voltage stabilizing capacitor 38 are respectively taken as an example. The transformer 30 has a primary side and a secondary side. The primary side has a first winding 50, a second winding 52, a first end, a second end and a third end. The third end is located between the first end and the second end In between, the first winding 50 is located between the first end and the third end, and the second winding 52 is located between the third end and the second end. The first electronic switch 32 is electrically connected between a high voltage terminal HV and the second terminal on the primary side, and the second electronic switch 34 is electrically connected between a low voltage terminal LV and the first terminal on the primary side. The first voltage stabilizing capacitor 36 and the second voltage stabilizing capacitor 38 are electrically connected in series between the high voltage terminal HV and the low voltage terminal LV to stabilize the voltage between the high voltage terminal HV and the low voltage terminal LV. One end of the balancing capacitor 40 is electrically connected between the first voltage stabilizing capacitor 36 and the second voltage stabilizing capacitor 38, and the other end is electrically connected to the third end of the primary side. The power supply circuit 42 is electrically connected to the secondary side and a load 54. The controller 48 is electrically connected to the first electronic switch 32 and the second electronic switch 34 to control the switching states of the first electronic switch 32 and the second electronic switch 34.

When a DC voltage is generated between the high voltage terminal HV and the low voltage terminal LV, and the controller 48 controls the first electronic switch 32 and the second electronic switch 34 to conduct, the DC voltage passes through the first electronic switch 32 and the second electronic switch 34 Energy is stored in the first winding 50 and the second winding 52. When a DC voltage is generated between the high voltage terminal HV and the low voltage terminal LV, and the controller 48 controls the first electronic switch 32 and the second electronic switch 34 to be turned off, the transformer 30 uses the above energy to provide the output voltage to the load through the power supply circuit 42 54. In order to make the cross voltage of the first electronic switch 32 and the second electronic switch 34 equal when turned off, the following relationship must be met: the first total cross voltage VT1 of the second winding 52 and the first electronic switch 32 is equal to the balancing capacitor 40 The second total cross-voltage VT2 with the first voltage stabilizing capacitor 36, the third total cross-voltage VT3 of the first winding 50 and the second electronic switch 34 is equal to the fourth total cross-voltage VT4 of the balancing capacitor 40 and the second voltage stabilizing capacitor 38 , The sum of the first total span voltage VT1 and the fourth total span voltage VT4 is equal to the sum of the second total span voltage VT2 and the third total span voltage VT3, the sum of the second total span voltage VT2 and the third total span voltage VT3 is equal to the DC Voltage. When the above relationship can be met, the cross voltages of the first voltage stabilizing capacitor 36, the second voltage stabilizing capacitor 38, the first winding 50 and the second winding 52 can be balanced with each other to balance the first electronic switch 32 and the second electronic switch 34 cross pressure. In addition, because the above relationship is met, the voltage across the first voltage stabilizing capacitor 36 is proportional to the voltage across the second winding 52, and the voltage across the second voltage stabilizing capacitor 38 is proportional to the voltage across the first winding 50. The voltage across the first voltage stabilizing capacitor 36 is inversely proportional to the voltage across the first winding 50, and the voltage across the second voltage stabilizing capacitor 38 is inversely proportional to the voltage across the second winding 52. When the crossover voltages of the first winding 50 and the second winding 52 are the same, the crossover voltages of the first voltage stabilizing capacitor 36 and the second voltage stabilizing capacitor 38 are also the same. Therefore, when the number of coils of the first winding 50 and the second winding 52 is the same, the capacitance values of the first voltage stabilizing capacitor 36 and the second voltage stabilizing capacitor 38 are the same.

For example, assuming that the DC voltage is 600 volts, in order to make the cross voltage of the first electronic switch 32 and the second electronic switch 34 equal, for example equal to 150 volts, according to the above relationship, the cross voltage of the second winding 52 is 250 volts, The span voltage of the second voltage stabilizing capacitor 38 is 150 volts, the span voltage of the balancing capacitor 40 is 50 volts, the span voltage of the first voltage stabilizing capacitor 36 is 350 volts, and the span voltage of the first winding 50 is 50 volts. If the voltage across the first winding 50 and the second winding 52 are both equal to 150 volts, the voltage across the first voltage stabilizing capacitor 36 and the second voltage regulating capacitor 38 are both equal to 300 volts, so that the first electronic switch 32 and the second electronic The voltage across the switch 34 is equal to 150 volts. In other words, the present invention only needs to design the first voltage stabilizing capacitor 36, the second voltage stabilizing capacitor 38, and the balancing capacitor 40 to have appropriate cross-voltage and capacitance values, and at the same time to match the appropriate number of coils and span of the first winding 50 and the second winding 52 Voltage, it is possible to balance the voltage across the first electronic switch 32 and the second electronic switch 34 without changing the internal structure of the first electronic switch 32 and the second electronic switch 34, so as to improve the stability of the power conversion device Performance, making component selection more flexible.

In addition, for the stability of the power conversion device, the positive electrode of the first rectifier diode 44 is electrically connected to the first end of the primary side and the second electronic switch 34, the negative electrode is electrically connected to the high voltage terminal HV, and the first rectifier diode 44 Block the surge from the high voltage terminal HV to the primary side. Similarly, the positive electrode of the second rectifier diode 46 is electrically connected to the second end of the primary side and the first electronic switch 32, the negative electrode is electrically connected to the low voltage terminal LV, and the second rectifier diode 46 blocks the surge from the low voltage The terminal LV is transmitted to the primary side. The first embodiment of the power conversion device uses a flyback conversion device as an example, so the secondary side has a fourth terminal and a fifth terminal, and the power supply circuit 42 includes a first diode 56 and a power supply capacitor 58 . The positive electrode of the first diode 56 is electrically connected to the fourth end of the secondary side, and the negative electrode is electrically connected to the load 54. One end of the supply capacitor 58 is electrically connected to the load 54 and the negative electrode of the first diode 56, and the other end is electrically connected to the load 54, a ground end and the fifth end of the secondary side. The transformer 30 uses energy to pass through the first diode 56 and the power supply capacitor 58 provide the output voltage to the load 54.

Please refer to FIG. 3 below to introduce the second embodiment of the power conversion device of the present invention. The second embodiment of the power conversion device uses the forward conversion device as an example. Compared with the first embodiment, the power supply circuit 42 of the second embodiment further includes a second diode 60 and an inductor 62. The positive electrode of the second diode 60 is electrically connected to the ground end and the fifth end of the secondary side, and the negative electrode is electrically connected to the negative electrode of the first diode 56. One end of the inductor 62 is electrically connected to the negative poles of the first diode 56 and the second diode 60, and the other end is electrically connected to the power supply capacitor 58 and the load 54. The transformer 30 uses energy through the first diode 56 and the second diode The pole body 60, the inductor 62 and the power supply capacitor 58 provide the output voltage to the load 54. Since the operation mode of the primary side is the same as that of the first embodiment, it will not be repeated here, so the same purpose can be achieved.

Please refer to FIG. 4 and introduce the third embodiment of the power conversion device of the present invention. The power conversion device includes a transformer 30, a first electronic switch 32, a second electronic switch 34, at least one voltage stabilizing capacitor 64, a first balancing capacitor 66, a second balancing capacitor 68, a power supply circuit 42, a first A rectifier diode 44, a second rectifier diode 46 and a controller 48, wherein the first electronic switch 32 and the second electronic switch 34 take the metal oxide half field effect transistor as an example, but the present invention does not take This limit is limited to one. The transformer 30 has a primary side and a secondary side. The primary side has a first winding 50, a second winding 52, a first end, a second end and a third end. The third end is located between the first end and the second end In between, the first winding 50 is located between the first end and the third end, and the second winding 52 is located between the third end and the second end. The first electronic switch 32 is electrically connected between a high voltage terminal HV and the second terminal on the primary side, and the second electronic switch 34 is electrically connected between a low voltage terminal LV and the first terminal on the primary side. The voltage stabilizing capacitor 64 is electrically connected between the high-voltage terminal HV and the low-voltage terminal LV to stabilize the voltage between the high-voltage terminal HV and the low-voltage terminal LV. The first balancing capacitor 66 is electrically connected between the third terminal on the primary side and the high voltage terminal HV. The second balancing capacitor 68 is electrically connected between the third terminal on the primary side and the low voltage terminal LV. The power supply circuit 42 is electrically connected to the secondary side and a load 54. The controller 48 is electrically connected to the first electronic switch 32 and the second electronic switch 34 to control the switching states of the first electronic switch 32 and the second electronic switch 34.

When a DC voltage is generated between the high voltage terminal HV and the low voltage terminal LV, and the controller 48 controls the first electronic switch 32 and the second electronic switch 34 to conduct, the DC voltage passes through the first electronic switch 32 and the second electronic switch 34 Energy is stored in the first winding 50 and the second winding 52. When a DC voltage is generated between the high voltage terminal HV and the low voltage terminal LV, and the controller 48 controls the first electronic switch 32 and the second electronic switch 34 to be turned off, the transformer 30 uses the above energy to provide the output voltage to the load through the power supply circuit 42 54. In order to enable the first electronic switch 32 and the second electronic switch 34 to be equal in cross-over voltage, the following relationship must be satisfied: the first total cross-voltage VT1 of the first electronic switch 32 and the second winding 52 is equal to the first balance The voltage across VC1 of the capacitor 66, the second total voltage across the second electronic switch 34 and the first winding 50 VT2 is equal to the voltage across the second balanced capacitor 68 VC2, the second winding 52, the second balancing capacitor 68 and the first electronic switch The third total cross-voltage VT3 of 32 is equal to the first total winding 50, the first balancing capacitor 66 and the fourth total cross-voltage VT4 of the second electronic switch 34. The fourth total cross-voltage VT4 is equal to the first balancing capacitor 66 and the second balancing capacitor 68 of the fifth total span pressure VT5. When the above relationship can be met, the cross voltages of the first voltage stabilizing capacitor 36, the second voltage stabilizing capacitor 38, the first winding 50 and the second winding 52 can be balanced with each other to balance the first electronic switch 32 and the second electronic switch 34 cross pressure. In addition, when the above relationship is met, the cross-voltage VC1 of the first balancing capacitor 66 is proportional to the cross-voltage of the second winding 52, and the cross-voltage VC2 of the second balancing capacitor 68 is proportional to the cross-voltage of the first winding 50. The voltage across VC1 of the first balancing capacitor 66 is inversely proportional to the voltage across the first winding 50, and the voltage across the VC2 of the second balancing capacitor 68 is inversely proportional to the voltage across the second winding 52. When the crossover voltages of the first winding 50 and the second winding 52 are the same, the crossover voltages VC1 and VC2 of the first balancing capacitor 66 and the second balancing capacitor 68 are also the same. Therefore, when the number of coils of the first winding 50 and the second winding 52 is the same, the capacitance values of the first balancing capacitor 66 and the second balancing capacitor 68 are the same.

For example, assuming that the DC voltage is 600 volts, in order to make the cross voltage of the first electronic switch 32 and the second electronic switch 34 equal, for example equal to 150 volts, according to the above relationship, the cross voltage of the second winding 52 is 200 volts, The voltage across VC2 of the second balancing capacitor 68 is 250 volts, the voltage across the VC1 of the first balancing capacitor 66 is 350 volts, and the voltage across the first winding 50 is 100 volts. Alternatively, the voltage across the second winding 52 is 100 volts, the voltage across the second balancing capacitor 68 VC2 is 350 volts, the voltage across the first balancing capacitor 66 VC1 is 250 volts, and the voltage across the first winding 50 is 200 volts. If the voltage across the first winding 50 and the second winding 52 are both equal to 150 volts, the voltage across the first balancing capacitor 66 and the second balancing capacitor 68 are both equal to 300 volts, so that the first electronic switch 32 and the second electronic switch 34 The span voltage is equal to 150 volts. In other words, as long as the first balanced capacitor 66 and the second balanced capacitor 68 are designed to have appropriate cross-voltage and capacitance values, together with the appropriate number of coils and cross-voltage of the first winding 50 and the second winding 52, the present invention can On the premise of changing the internal structure of the first electronic switch 32 and the second electronic switch 34, to balance the voltage across the first electronic switch 32 and the second electronic switch 34, in order to improve the stability of the power conversion device and make the component selection more elasticity.

In addition, for the stability of the power conversion device, the positive electrode of the first rectifier diode 44 is electrically connected to the first end of the primary side and the second electronic switch 34, the negative electrode is electrically connected to the high voltage terminal HV, and the first rectifier diode 44 Block the surge from the high voltage terminal HV to the primary side. Similarly, the positive electrode of the second rectifier diode 46 is electrically connected to the second end of the primary side and the first electronic switch 32, the negative electrode is electrically connected to the low voltage terminal LV, and the second rectifier diode 46 blocks the surge from the low voltage The terminal LV is transmitted to the primary side. The third embodiment of the power conversion device takes a flyback conversion device as an example, so the secondary side has a fourth terminal and a fifth terminal, and the power supply circuit 42 includes a first diode 56 and a power supply capacitor 58 . The positive electrode of the first diode 56 is electrically connected to the fourth end of the secondary side, and the negative electrode is electrically connected to the load 54. One end of the supply capacitor 58 is electrically connected to the load 54 and the negative electrode of the first diode 56, and the other end is electrically connected to the load 54, a ground end and the fifth end of the secondary side. The transformer 30 uses energy to pass through the first diode 56 and the power supply capacitor 58 provide the output voltage to the load 54.

Please refer to FIG. 5 below to introduce the fourth embodiment of the power conversion device of the present invention. The fourth embodiment of the power conversion device takes the forward conversion device as an example. Compared with the third embodiment, the power supply circuit 42 of the fourth embodiment further includes a second diode 60 and an inductor 62. The positive electrode of the second diode 60 is electrically connected to the ground end and the fifth end of the secondary side, and the negative electrode is electrically connected to the negative electrode of the first diode 56. One end of the inductor 62 is electrically connected to the negative poles of the first diode 56 and the second diode 60, and the other end is electrically connected to the power supply capacitor 58 and the load 54. The transformer 30 uses energy through the first diode 56 and the second diode The pole body 60, the inductor 62 and the power supply capacitor 58 provide the output voltage to the load 54. Since the operation mode of the primary side is the same as that of the third embodiment, it will not be repeated here, so the same purpose can be achieved.

In summary, the present invention designs the balancing capacitor and the primary side of the transformer to have an appropriate voltage across, so that the first electronic switch and the second electronic switch can be balanced without changing the internal structure of the first electronic switch and the second electronic switch. 2. The cross voltage of the electronic switch can improve the stability of the power conversion device and make the component selection more flexible.

The above is only a preferred embodiment of the present invention and is not intended to limit the scope of the implementation of the present invention. Therefore, all changes and modifications based on the shape, structure, characteristics and spirit described in the patent application scope of the present invention are cited. , Should be included in the scope of the patent application of the present invention.

10: The first electronic switch 12: Second electronic switch 14: Controller 16: Transformer 18: First diode 20: Second diode 22: Voltage stabilizing capacitor 24: third diode 26: load capacitance 28: load 30: Transformer 32: The first electronic switch 34: Second electronic switch 36: First regulator capacitor 38: Second regulator capacitor 40: balance capacitor 42: Power supply circuit 44: First rectifier diode 46: Second rectifier diode 48: controller 50: first winding 52: Second winding 54: load 56: First diode 58: Power supply capacitor 60: Second diode 62: Inductance 64: Voltage stabilizing capacitor 66: First balancing capacitor 68: second balancing capacitor

FIG. 1 is a schematic circuit diagram of a prior art power conversion device. FIG. 2 is a circuit schematic diagram of the first embodiment of the power conversion device of the present invention. FIG. 3 is a schematic circuit diagram of a second embodiment of the power conversion device of the present invention. FIG. 4 is a schematic circuit diagram of a third embodiment of the power conversion device of the present invention. FIG. 5 is a schematic circuit diagram of a fourth embodiment of the power conversion device of the present invention.

30: Transformer

32: The first electronic switch

34: Second electronic switch

36: First regulator capacitor

38: Second regulator capacitor

40: balance capacitor

42: Power supply circuit

44: First rectifier diode

46: Second rectifier diode

48: controller

50: first winding

52: Second winding

54: load

56: First diode

58: Power supply capacitor

Claims (17)

A power conversion device includes: a transformer with a primary side and a secondary side, the primary side having a first winding, a second winding, a first end, a second end and a third end, the third end is located Between the first end and the second end, the first winding is located between the first end and the third end, the second winding is located between the third end and the second end, the first winding There is energy with the second winding; a first electronic switch electrically connected between a high voltage terminal and the second terminal; a second electronic switch electrically connected between a low voltage terminal and the first terminal Between; at least one first voltage stabilizing capacitor and at least one second voltage stabilizing capacitor, electrically connected in series between the high voltage end and the low voltage end; a balancing capacitor, one end of which is electrically connected to the at least one first Between a voltage stabilizing capacitor and the at least one second voltage stabilizing capacitor, the other end is electrically connected to the third end; and a power supply circuit is electrically connected to the secondary side and a load, at the high voltage end and the low A DC voltage is generated between the voltage terminals, and when the first electronic switch and the second electronic switch are turned off, the transformer uses the energy to provide an output voltage to the load through the power supply circuit, the second winding and the first electron The first total voltage across the switch is equal to the second total voltage across the balanced capacitor and the at least one first voltage stabilizing capacitor, and the third total voltage across the first winding and the second electronic switch is equal to the balanced capacitor and the at least one A fourth total span voltage of a second voltage stabilizing capacitor, the sum of the first total span voltage and the fourth total span voltage is equal to the sum of the second total span voltage and the third total span voltage, the second total span The sum of the voltage and the third total crossover voltage is equal to the DC voltage, and the crossover voltages of the at least one first voltage stabilizing capacitor, the at least one second voltage stabilizing capacitor, the first winding and the second winding are balanced with each other to Balancing the voltage across the first electronic switch and the second electronic switch; Wherein the cross voltage of the at least one first voltage stabilizing capacitor is proportional to the cross voltage of the second winding, the cross voltage of the at least one second voltage stabilizing capacitor is proportional to the cross voltage of the first winding, and the at least one first voltage stabilizing capacitor The voltage across is inversely proportional to the voltage across the first winding, and the voltage across the at least one second voltage stabilizing capacitor is inversely proportional to the voltage across the second winding. The power conversion device according to claim 1, wherein when the number of coils of the first winding and the second winding is the same, the capacitance values of the at least one first voltage stabilizing capacitor and the at least one second voltage stabilizing capacitor are the same. The power conversion device according to claim 1, wherein the secondary side has a fourth terminal and a fifth terminal, and the power supply circuit includes: a first diode whose positive electrode is electrically connected to the fourth terminal and whose negative electrode is electrically Connected to the load; and a power supply capacitor, one end of which is electrically connected to the load and the negative pole of the first diode, the other end is electrically connected to the load, a ground end and the fifth end, the transformer uses the energy to penetrate The first diode and the power supply capacitor provide the output voltage to the load. The power conversion device according to claim 3, wherein the power supply circuit further includes: a second diode whose positive electrode is electrically connected to the ground terminal and the fifth terminal, and whose negative electrode is electrically connected to the first diode The negative electrode; and an inductor, one end of which is electrically connected to the negative electrode of the first diode and the second diode, and the other end is electrically connected to the power supply capacitor and the load, and the transformer uses the energy to pass through the second The diode and the inductor provide the output voltage to the load. The power conversion device according to claim 1, wherein when the DC voltage is generated and the first electronic switch and the second electronic switch are turned on, the DC voltage stores the energy through the first electronic switch and the second electronic switch The first winding and the second winding in. The power conversion device according to claim 1, wherein the first electronic switch and the second electronic switch are metal oxide half field effect transistors. The power conversion device according to claim 1, further comprising a first rectifier diode, the positive electrode of which is electrically connected to the first terminal and the second electronic switch, and the negative electrode is electrically connected to the high voltage terminal, and the first rectifier The diode blocks the surge from the high voltage end to the primary side. The power conversion device according to claim 7, further comprising a second rectifier diode whose positive electrode is electrically connected to the second terminal and the first electronic switch, and whose negative electrode is electrically connected to the low voltage terminal and the second rectifier The diode blocks the surge from the low voltage end to the primary side. A power conversion device includes: a transformer with a primary side and a secondary side, the primary side having a first winding, a second winding, a first end, a second end and a third end, the third end is located Between the first end and the second end, the first winding is located between the first end and the third end, the second winding is located between the third end and the second end, the first winding There is energy with the second winding; a first electronic switch electrically connected between a high voltage terminal and the second terminal; a second electronic switch electrically connected between a low voltage terminal and the first terminal Between; a first balancing capacitor electrically connected between the third terminal and the high voltage terminal; a second balancing capacitor electrically connected between the third terminal and the low voltage terminal; and a power supply The circuit is electrically connected to the secondary side and a load, generates a DC voltage between the high voltage terminal and the low voltage terminal, and when the first electronic switch and the second electronic switch are turned off, the transformer uses the Energy provides the output voltage to the negative through the power supply circuit Load, the first total voltage across the first electronic switch and the second winding is equal to the voltage across the first balanced capacitor, the second total voltage across the second electronic switch and the first winding is equal to the second voltage across The voltage across, the third total voltage across the second winding, the second balancing capacitor and the first electronic switch is equal to the fourth voltage across the first winding, the first balancing capacitor and the second electronic switch, The fourth total crossover voltage is equal to the fifth total crossover voltage of the first balanced capacitor and the second balanced capacitor, and the crossover voltage of the first balanced capacitor, the second balanced capacitor, the first winding and the second winding Balanced with each other to balance the voltage across the first electronic switch and the second electronic switch; wherein the voltage across the first balanced capacitor is proportional to the voltage across the second winding, and the voltage across the second balanced capacitor is proportional to the first The voltage across the winding, the voltage across the first balancing capacitor is inversely proportional to the voltage across the first winding, and the voltage across the second balancing capacitor is inversely proportional to the voltage across the second winding. The power conversion device according to claim 9, further comprising at least one voltage stabilizing capacitor, which is electrically connected between the high voltage terminal and the low voltage terminal. The power conversion device according to claim 9, wherein when the number of coils of the first winding and the second winding is the same, the capacitance values of the first balancing capacitor and the second balancing capacitor are the same. The power conversion device according to claim 9, wherein the secondary side has a fourth terminal and a fifth terminal, and the power supply circuit includes: a first diode whose positive electrode is electrically connected to the fourth terminal and negative electrode is electrically Connected to the load; and a power supply capacitor, one end of which is electrically connected to the load and the negative pole of the first diode, the other end is electrically connected to the load, a ground end and the fifth end, the transformer uses the energy to penetrate The first diode and the power supply capacitor provide the output voltage to the load. The power conversion device according to claim 12, wherein the power supply circuit further includes: A second diode whose positive electrode is electrically connected to the ground end and the fifth end, and whose negative electrode is electrically connected to the negative electrode of the first diode; and an inductor whose one end is electrically connected to the first diode The negative electrode of the second diode and the other end are electrically connected to the power supply capacitor and the load. The transformer uses the energy to provide the output voltage to the load through the second diode and the inductor. The power conversion device according to claim 9, wherein when the DC voltage is generated and the first electronic switch and the second electronic switch are turned on, the DC voltage stores the energy through the first electronic switch and the second electronic switch In the first winding and the second winding. The power conversion device according to claim 9, wherein the first electronic switch and the second electronic switch are metal oxide half field effect transistors. The power conversion device according to claim 9, further comprising a first rectifier diode whose positive electrode is electrically connected to the first terminal and the second electronic switch, and whose negative electrode is electrically connected to the high voltage terminal and the first rectifier The diode blocks the surge from the high voltage end to the primary side. The power conversion device according to claim 16, further comprising a second rectifier diode whose positive electrode is electrically connected to the second terminal and the first electronic switch, and whose negative electrode is electrically connected to the low voltage terminal and the second rectifier The diode blocks the surge from the low voltage end to the primary side.

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