TWI752360B - Widened-voltage bidirectional isolated multi-level dc-dc converter and method thereof - Google Patents

Abstract

A bidirectional multi-level DC-DC converter device has a widened-voltage conversion feature and includes a first power converter, a transformer, a second power converter, a third power converter, a first selective switch, a second selective switch and a filter circuit. A first winding at a primary side of the transformer connects with the first power converter while a second winding and a third winding at a secondary side of the transformer connect with the second power converter and the third power converter. The first selective switch connects with a first positive DC output end of the second power converter while the second selective switch connects with a first negative DC output end of the second power converter and a second positive DC output end of the third power converter. The filter circuit connects with an output end the first selective switch, an output end of the second selective switch and a second negative DC output end of the third power converter.

Description

Bidirectional isolated multi-stage DC-DC power conversion device with wide voltage range and method therefor

The present invention relates to a bidirectional isolated multi-stage DC-DC power conversion device with a wide voltage range and a method thereof; in particular, to a bidirectional isolated type capable of outputting a variably wide voltage range A multi-stage DC-DC power conversion device and method thereof; more particularly, a bidirectional isolated multi-stage DC-DC power conversion device and a method with a wide voltage range capable of reducing dimensions-reduced size.

In general, conventional isolated DC-DC power converters have been widely used in various technical fields. Although the traditional isolated DC-DC power converter has the advantages of simple control, it has the disadvantages of low efficiency, high ripple, high electromagnetic interference and large capacity of the filter circuit required. In contrast, although the conventional multi-order DC-DC power converter has the disadvantage of being more complicated to control, it has the advantages of relatively high efficiency, relatively small electromagnetic interference and small capacity of the filter circuit required. .

For example, FIG. 1 shows a schematic structural diagram of a conventional multi-stage DC-DC power conversion device. Referring to FIG. 1, the conventional multi-stage DC-DC power conversion device 9 includes a transformer 90, and the transformer 90 has a low voltage side (left side) and a high voltage side (right side). The low voltage side has an inductor 911 and four diodes 912 . Conversely, the high-voltage side is set Six high-side switches 92 and two diodes 93 .

However, the multi-stage DC-DC power conversion device 9 obviously has the disadvantages of complex structure, increased cost and bulky high-voltage side circuit of the transformer 90 , and its power can only be transmitted in one direction. Therefore, in order to simplify the overall structure, reduce the cost and reduce the volume, it may be considered to omit some components (for example, omit two diodes 93 ) on the high voltage side of the transformer 90 .

Another conventional bidirectional DC/DC converter, such as the patent application "Bidirectional DC-DC converter and method for controlling the same" in US Patent Publication No. US-20090059622, discloses a bidirectional DC/DC converter and its control method. The bidirectional DC/DC converter has a transformer connected to a voltage type full bridge circuit and a current type switching circuit. The voltage-type full-bridge circuit is connected to a first power supply, and the current-type switching circuit is connected to a second power supply. A voltage clamping circuit consists of several switching elements, and a clamping capacitor is connected to the current mode switching circuit. The bidirectional DC/DC converter has a control circuit for coordinating the action of the switching element so as to control a circulating current in a resonance reactor.

Another conventional bidirectional DC/DC converter, such as the patent application "Bidirectional DC-DC converter and control method thereof" of US Patent Publication No. US-20120098341, discloses a bidirectional DC/DC converter and a control method thereof. The bidirectional DC/DC converter includes a transformer, several switching circuits, a diode connected to a switch, several smoothing capacitors and a control unit. A first power source and a second power source are connected in parallel with the smoothing capacitor to transmit power bidirectionally. The switch is maintained in the ON state when being transferred from the first power source to the high voltage power source. Conversely, when the second power supply is transmitted to the first power supply, the switch is maintained in the OFF state to prevent the reverse of the first power supply Reverse electrical power flow.

Another conventional bidirectional DC/DC converter, such as the patent application "Soft switching DC-DC converter" of US Patent Publication No. US-20060176719, discloses a flexible switching DC/DC converter. The flexible switching DC/DC converter includes: a first switching element having a first terminal connected to an input side and a control terminal for controlling a main electric current; a first diode having a The first end is connected to a second end of the first switching element; a transformer main coil has a main coil and a secondary coil, and the transformer main coil is connected to the second end of the first switching element; a second two The pole body has a first end connected to the first end of the first switching element; a second switching element has a first end connected to a second end of the second diode; and the secondary coil of the transformer has A first end is connected to a second end of the second switching element, and the secondary winding of the transformer has a second end connected to the second end of the first switching element.

Another conventional bidirectional DC/DC converter, such as the patent application "DC-DC converter" of US Patent Publication No. US-20160087545, discloses a DC/DC converter. A first switching circuit is connected between the first coil of a transformer and the DC power supply. A second switching circuit is connected between a second coil of a transformer and a battery. When charging the battery, a control circuit turns off an element of a second bridge circuit in the second switching circuit, controls a phase offset of a first diagnostic element, and controls in the second switching circuit A phase offset of a second diagnostic element relative to a drive phase of a first reference element of a first bridge circuit in the first switching circuit. When the battery is discharged, the control circuit turns off an element of the first bridge circuit, and controls a phase offset of a second diagnostic element and a phase offset of the first diagnostic element, which are relative to the One of the second reference elements of the second bridge circuit drives the phase.

Another conventional bidirectional DC/DC converter, eg: Applicant The "Bidirectional isolated multi-level DC-DC converter and method thereof" of US Patent No. US-9787201 has been approved, which discloses a bidirectional isolated multi-level DC-DC power conversion device and a method thereof. The multi-stage DC-DC power conversion device includes providing an inverter, a high-frequency transformer with three windings, a first full-bridge rectifier, a second full-bridge rectifier, a selection circuit and a filter circuit. The first winding on the primary side of the high-frequency transformer is connected to the inverter, and the second winding and the third winding on the secondary side of the high-frequency transformer are respectively connected to the first full-bridge rectifier and the second full-bridge rectifier. The selection circuit is connected to the DC output terminals of the first full-bridge rectifier and the second full-bridge rectifier, and is used for selecting the operation mode of the first full-bridge rectifier and the second full-bridge rectifier to be two full-bridge rectifiers Output in series or by a single full bridge rectifier to output two voltage levels to form a multi-level output voltage. The filter circuit is connected between the selection circuit and a load for filtering out harmonics and outputting a DC voltage.

However, the bidirectional DC/DC converters of the aforementioned US Patent Publication Nos. US-20090059622, US-20120098341, US-20060176719, US-20160087545 and US-9787201 still need further improvement, and There must be a need to further simplify the structure and improve the power conversion efficiency. The aforementioned US patent application is only for reference to the technical background of the present invention and to illustrate the current state of the art, and is not intended to limit the scope of the present invention.

In view of this, in order to meet the above requirements, the present invention provides a bidirectional isolated multi-stage DC-DC power conversion device with a wide voltage range and a method thereof, comprising a first power converter, a transformer, and a second power converter, a third power converter, a first selection switch, a second selection switch and a filter circuit, and by controlling the first power converter, the second power converter, the third power converter, the first power converter A selector switch and a second selector switch can expand the output of a variable voltage range (for example: the range of 50V to 500V or other voltage ranges), so as to reduce the filter circuit capacity, in order to achieve the purpose of expanding the output voltage range, bidirectional power conversion and improving operating efficiency, and improve the function and performance of conventional bidirectional multi-stage DC-DC power conversion devices.

The main purpose of the preferred embodiments of the present invention is to provide a bidirectional isolated multi-stage DC-DC power conversion device with a wide voltage range and a method thereof, comprising a first power converter, a transformer, and a second power converter , a third power converter, a first selection switch, a second selection switch and a filter circuit, and by controlling the first power converter, the second power converter, the third power converter, the first selection switch The switch and the second selection switch can expand the output variable voltage range (for example: the range of 50V to 500V or other voltage ranges), so as to reduce the capacity of the filter circuit, so as to expand the output voltage range, bidirectional power conversion and improve operating efficiency purpose.

Another object of the preferred embodiments of the present invention is to provide a bidirectional isolated multi-stage DC-DC power conversion device with a wide voltage range and a method thereof, comprising a first power converter, a transformer, and a second power converter converter, a third power converter, a first selection switch, a second selection switch and a filter circuit, which only use a single first power converter and a single transformer, and control the first selection switch The switch and the second selection switch can generate a low harmonic voltage pulse voltage output to the filter circuit, so as to reduce the capacity of the filter circuit, so as to achieve the purpose of reducing the volume, reducing the manufacturing cost and improving the operation efficiency.

In order to achieve the above object, the bidirectional isolated multi-stage DC-DC power conversion device with a wide voltage range according to a preferred embodiment of the present invention includes: a DC/DC converter including a first input/output side and a second input/output side; a first power converter disposed between the first input/output side and the second input/output side of the DC/DC converter, and the first power converter The energy converter is selected from a half-bridge power converter; a transformer is arranged on the DC/DC converter, and the transformer includes a primary side and a secondary side, and the primary side of the transformer has a first winding, and the The first winding of the transformer is connected to the first power converter, and the secondary side of the transformer has a second winding and a third winding; a second power converter whose input is connected to the second winding of the transformer , and the second power converter has a first DC positive output terminal and a first DC negative output terminal, and the second power converter is selected from a half-bridge power converter; a third power converter, which The input is connected to the third winding of the transformer, the third power converter has a second DC positive output terminal and a second DC negative output terminal, and the second DC positive output terminal of the third power converter is connected to the The first DC negative output terminal of the second power converter, and the third power converter is selected from the half-bridge power converter; a first selection switch is connected to the first DC of the second power converter a positive output terminal; a second selection switch connected to the first DC negative output terminal of the second power converter and the second DC positive output terminal of the third power converter; and a filter circuit connected to the The output terminal of the first selection switch, the output terminal of the second selection switch and the second negative DC output terminal of the third power converter; wherein when a high voltage DC input is input to the first input/output side of the DC/DC converter When the second power converter, the third power converter and the second selection switch are cut off, and the first power converter and the first selection switch are controlled to operate, so that the DC/DC converter The second input/output side selects to output a low voltage to a high voltage; or wherein when the input DC voltage is input to the DC/DC converter When the second input/output side of the converter is used, the first power converter and the first selection switch are cut off, and the second power converter, the third power converter and the second selection switch are controlled to operate , so as to select and output a fixed voltage from the first input/output side of the DC/DC converter.

The first power converter of the preferred embodiment of the present invention is selected from a full-bridge power converter.

In a preferred embodiment of the present invention, the second power converter and the third power converter are selected from a full-bridge power converter.

In a preferred embodiment of the present invention, when the second power converter is selected as a half-bridge power converter, the first DC positive output terminal and the first DC negative output terminal of the second power converter are connected in parallel to a first DC power converter. A capacitor bank and a second capacitor bank form the first output DC voltage.

In a preferred embodiment of the present invention, when the third power converter is selected as a half-bridge power converter, the second DC positive output terminal and the second DC negative output terminal of the third power converter are connected in parallel with a third capacitor bank and a fourth capacitor bank to form the second output DC voltage.

In a preferred embodiment of the present invention, when the second power converter is selected as a full-bridge power converter, the first DC positive output terminal and the first DC negative output terminal of the second power converter are connected in parallel with a first DC power converter. A capacitor bank forms the first output DC voltage.

In a preferred embodiment of the present invention, when the third power converter is selected as a full-bridge power converter, the second DC positive output terminal and the second DC negative output terminal of the third power converter are connected in parallel with a second capacitor group to form the second output DC voltage.

The preferred embodiment of the present invention utilizes operation to control the first output DC voltage and the second output DC voltage, so as to output two voltage levels to form a multi-level output voltage.

In order to achieve the above object, the bidirectional isolated multi-stage DC-DC power conversion method with a wide voltage range according to a preferred embodiment of the present invention includes: A first power converter, a transformer, a second power converter, a third power converter, a first selection switch, a second selection switch and a filter circuit are provided in the DC/DC converter, and the The DC/DC converter includes a first input/output side and a second input/output side; the first power converter is connected to an input DC voltage source; the primary side of the transformer has a first winding, and connects the The first winding of the primary side of the transformer is connected to an AC output end of the first power converter, and the secondary side of the transformer has a second winding and a third winding; the input of the second power converter The second winding is connected to the secondary side of the transformer, and the second power converter has a first DC positive output terminal and a first DC negative output terminal, and the first DC positive output terminal and the first DC positive output terminal The DC negative output terminal forms a first output DC voltage; the input of the third power converter is connected to the third winding of the secondary side of the transformer, and the third power converter has a second DC positive output terminal and A second DC negative output terminal, and the second DC positive output terminal and the second DC negative output terminal form a second output DC voltage, and the second DC positive output terminal of the third power converter is connected to the second DC positive output terminal the first DC negative output terminal of the power converter; the first selection switch is connected to the first DC positive output terminal of the second power converter; the second selection switch is connected to the second power converter the first DC negative output terminal and the second DC positive output terminal of the third power converter; the filter circuit is connected to the output terminal of the first selection switch, the output terminal of the second selection switch and the third power converter the second DC negative output terminal; When a high voltage DC input is input to the first input/output side of the DC/DC converter, the second power converter, the third power converter and the second selection switch are cut off, and the control operation of the The first power converter and the first selection switch are used to select and output a low voltage to a high voltage from the second input/output side of the DC/DC converter.

The first power converter of the preferred embodiment of the present invention is selected from a half-bridge power converter or a full-bridge power converter.

The second power converter and the third power converter in the preferred embodiment of the present invention are selected from a half-bridge power converter or a full-bridge power converter.

In a preferred embodiment of the present invention, when the second power converter is selected as a half-bridge power converter, the first DC positive output terminal and the first DC negative output terminal of the second power converter are connected in parallel to a first DC power converter. A capacitor bank and a second capacitor bank form the first output DC voltage.

In a preferred embodiment of the present invention, when the third power converter is selected as a half-bridge power converter, the second DC positive output terminal and the second DC negative output terminal of the third power converter are connected in parallel with a third capacitor bank and a fourth capacitor bank to form the second output DC voltage.

In a preferred embodiment of the present invention, when the second power converter is selected as a full-bridge power converter, the first DC positive output terminal and the first DC negative output terminal of the second power converter are connected in parallel with a first DC power converter. A capacitor bank forms the first output DC voltage.

In a preferred embodiment of the present invention, when the third power converter is selected as a full-bridge power converter, the second DC positive output terminal and the second DC negative output terminal of the third power converter are connected in parallel with a second capacitor group to form the second output DC voltage.

The preferred embodiment of the present invention utilizes operation to control the first output DC voltage and the second output DC voltage, so as to output two voltage levels to form a multi-level output voltage.

In order to achieve the above object, the bidirectional isolated multi-stage DC-DC power conversion method with a wide voltage range according to a preferred embodiment of the present invention includes: providing a first power converter, a transformer, a first power converter in the DC/DC converter Two power converters, a third power converter, a first selection switch, a second selection switch and a filter circuit, and the DC/DC converter includes a first input/output side and a second input/output the first power converter is connected to an input DC voltage source; the primary side of the transformer has a first winding, and the first winding of the primary side of the transformer is connected to an AC of the first power converter an output end, and the secondary side of the transformer has a second winding and a third winding; the input of the second power converter is connected to the second winding of the secondary side of the transformer, and the second power converter a first DC positive output terminal and a first DC negative output terminal, and the first DC positive output terminal and the first DC negative output terminal form a first output DC voltage; the third power converter The input is connected to the third winding of the secondary side of the transformer, and the third power converter has a second DC positive output terminal and a second DC negative output terminal, and the second DC positive output terminal and the second DC The negative output terminal forms a second output DC voltage, and the second DC positive output terminal of the third power converter is connected to the first DC negative output terminal of the second power converter; the first selection switch is connected to The first DC positive output terminal of the second power converter; the second selection switch is connected to the first DC negative output terminal of the second power converter and the second DC positive output terminal of the third power converter ; connect the filter circuit to the output of the first selection switch terminal, the output terminal of the second selection switch and the second negative DC output terminal of the third power converter; when the input DC voltage is input to the second input/output side of the DC/DC converter, the first power The converter and the first selection switch are cut off, and the second power converter, the third power converter and the second selection switch are controlled to operate, so that the first input/output side of the DC/DC converter is operated Select to output a fixed voltage.

The first power converter of the preferred embodiment of the present invention is selected from a half-bridge power converter or a full-bridge power converter.

The second power converter and the third power converter in the preferred embodiment of the present invention are selected from a half-bridge power converter or a full-bridge power converter.

In a preferred embodiment of the present invention, when the second power converter is selected as a half-bridge power converter, the first DC positive output terminal and the first DC negative output terminal of the second power converter are connected in parallel to a first DC power converter. A capacitor bank and a second capacitor bank form the first output DC voltage.

In a preferred embodiment of the present invention, when the third power converter is selected as a half-bridge power converter, the second DC positive output terminal and the second DC negative output terminal of the third power converter are connected in parallel with a third capacitor bank and a fourth capacitor bank to form the second output DC voltage.

In a preferred embodiment of the present invention, when the second power converter is selected as a full-bridge power converter, the first DC positive output terminal and the first DC negative output terminal of the second power converter are connected in parallel with a first DC power converter. A capacitor bank forms the first output DC voltage.

In a preferred embodiment of the present invention, when the third power converter is selected as a full-bridge power converter, the second DC positive output terminal and the second DC negative output terminal of the third power converter are connected in parallel with a second capacitor group to form the second output DC voltage.

The preferred embodiment of the present invention utilizes manipulation to control the first output The DC voltage and the second output DC voltage are used to output two voltage levels to form a multi-level output voltage.

10‧‧‧Bidirectional isolated multi-stage DC-DC power conversion device with wide voltage range

10a‧‧‧Bidirectional isolated multi-stage DC-DC power conversion device with wide voltage range

1‧‧‧First Half-Bridge Power Converter

1a‧‧‧First full-bridge power converter

2‧‧‧Transformer

21‧‧‧First winding

22‧‧‧Second winding

23‧‧‧Third winding

31‧‧‧Second half-bridge power converter

32‧‧‧Third Half-Bridge Power Converter

31a‧‧‧Second full-bridge power converter

32a‧‧‧Third full-bridge power converter

41‧‧‧First selector switch

42‧‧‧Second selector switch

5‧‧‧Filter circuit

9‧‧‧Conventional multi-stage DC-DC power conversion device

90‧‧‧Transformers

911‧‧‧Inductance

912‧‧‧Diode

92‧‧‧High-voltage side switch

93‧‧‧Diode

Figure 1: A schematic diagram of the structure of a conventional multi-stage DC-DC power conversion device.

FIG. 2 is a schematic diagram of the structure of the bidirectional isolated multi-stage DC-DC power conversion device with a wide voltage range for power conversion in the first power conversion direction according to the first preferred embodiment of the present invention.

FIG. 3 is a schematic diagram of the structure of the bidirectional isolated multi-stage DC-DC power conversion device with wide voltage range for power conversion in the second power conversion direction according to the first preferred embodiment of the present invention.

Figures 4(A) to 4(C): schematic diagrams of waveforms of the bidirectional isolated multi-stage DC-DC power conversion device with a wide voltage range using the control method in the first power conversion direction according to the preferred embodiment of the present invention.

Figures 5(A) and 5(B) are schematic diagrams of waveforms of the bidirectional isolated multi-stage DC-DC power conversion device with a wide voltage range using another control method in the second power conversion direction according to the preferred embodiment of the present invention.

FIG. 6 is a schematic diagram of the structure of the bidirectional isolated multi-stage DC-DC power conversion device with a wide voltage range for power conversion in the first power conversion direction according to the second preferred embodiment of the present invention.

FIG. 7 is a schematic diagram of the structure of the bidirectional isolated multi-stage DC-DC power conversion device with a wide voltage range for power conversion in the second power conversion direction according to the second preferred embodiment of the present invention.

In order to fully understand the present invention, preferred embodiments will be exemplified below and described in detail in conjunction with the accompanying drawings, which are not intended to limit the present invention.

A preferred embodiment of the present invention is a bidirectional isolated multi-stage DC-DC power conversion device with a wide voltage range, its structure, its operation method or The control method is applicable to various bidirectional multi-stage power conversion devices or devices with similar functions [the operation method or the control method thereof], but it is not intended to limit the application scope of the present invention.

FIG. 2 shows a schematic diagram of the structure of the bidirectional isolated multi-stage DC-DC power conversion device with a wide voltage range for power conversion in the first power conversion direction according to the first preferred embodiment of the present invention; FIG. 3 shows the first power conversion of the present invention. A schematic diagram of the structure of the bidirectional isolated multi-stage DC-DC power conversion device with a wide voltage range for power conversion in the second power conversion direction according to the preferred embodiment. Referring to Figures 2 and 3, the bidirectional isolated multi-stage DC-DC power conversion device 10 with a wide voltage range according to the first preferred embodiment of the present invention has a first input/output side [the left side of Figure 2] shown] and a second input/output side (shown on the right side of Figure 2), and the first input/output side can input several fixed voltages (eg 400V, 800V or other voltages), and the second input/output side The input/output side can expand and output a variable voltage range (for example: the range of 50V to 500V or other voltage ranges).

Please refer to FIGS. 2 and 3 again. For example, the bidirectional isolated multi-stage DC-DC power conversion device 10 with a wide voltage range includes a first half-bridge power converter 1 , a transformer 2 , and a A second half-bridge power converter 31 , a third half-bridge power converter 32 , a first selection switch 41 , a second selection switch 42 and a filter circuit 5 .

Please refer to FIG. 2 and FIG 3, for example, the first half-bridge power converter 1 comprises a first switch [for example: a power electronic switches S _1] and a second switch [for example: a power Electronic switch] S ₂ , a first capacitor bank C ₁ and a second capacitor bank C ₂ . The first half-bridge power converter 1 can be optionally changed into a full-bridge power converter or other power converters, and an input terminal of the first half-bridge power converter 1 is connected in parallel with an input DC voltage source V _in . In addition, the first half-bridge power converter 1 includes an AC output terminal.

Please refer to Figures 2 and 3 again, for example, the transformer The transformer 2 can be selected from a transformer with three windings, and the transformer 2 includes a primary side and a secondary side, and the primary side has a first winding 21, and the secondary side has a second winding 22 and a third winding twenty three. The first winding 21 of the transformer 2 is properly connected to the AC output terminal of the first half-bridge power converter 1 . In addition, the filter circuit 5 includes an inductor and a capacitor.

Referring to Figures 2 and 3, for example, the second half-bridge power converter 31 can be optionally changed to a full-bridge power converter or other power converters, and the second half-bridge power converter 31 The converter 31 has a third switch (eg, a power electronic switch) S ₃ , a fourth switch (eg, a power electronic switch) S ₄ , a third capacitor bank C ₃ and a fourth capacitor bank C ₄ . The AC input of the second half-bridge power converter 31 is connected to the second winding 22 of the transformer 2 , and the second half-bridge power converter 31 has a first DC positive output terminal and a first direct current flow negative output terminal, and the first positive DC output terminal and a first negative DC output terminal of a third capacitor connected in parallel to the fourth set of capacitors C ₃ and C ₄ form a first output DC voltage.

Referring to Figures 2 and 3, for example, the third half-bridge power converter 32 can be optionally changed to a full-bridge power converter or other power converters, and the third half-bridge power converter 32 The converter 32 has a fifth switch (eg, a power electronic switch) S ₅ , a sixth switch (eg, a power electronic switch) S ₆ , a fifth capacitor bank C ₅ and a sixth capacitor bank C ₆ . The AC input of the third half-bridge power converter 32 is connected to the third winding 23 of the transformer 2 , and the third half-bridge power converter 32 has a second DC positive output terminal and a second DC negative an output terminal, and the positive output terminal and a second DC negative output terminal of the second DC capacitor bank connected in parallel to the fifth capacitor C ₅ and C ₆ group VI to form a second output DC voltage, and the third half bridge The second DC positive output terminal of the power converter 32 is connected to the first DC negative output terminal of the second half-bridge power converter 31 .

Please refer to Figures 2 and 3 again, for example, the first selector switch (eg: power electronic switch) 41 has a first terminal (input/output terminal) and a second terminal (input/output terminal) , and the first terminal of the first selection switch 41 is connected to the first DC positive output terminal of the second half-bridge power converter 31 .

Referring again to Figures 2 and 3, for example, the second selector switch (eg, a power electronic switch) 42 has a first terminal (input/output terminal) and a second terminal (input/output terminal) , and the first terminal of the second selection switch 42 is connected to the first DC negative output terminal of the second half-bridge power converter 31 and the second DC positive output terminal of the third half-bridge power converter 32 .

Referring to Figures 2 and 3 again, for example, the filter circuit 5 is connected to the second terminal of the first selection switch 41 , the second terminal of the second selection switch 42 and the third half-bridge power converter The second DC negative output terminal of 32.

Figures 4(A) to 4(C) show the waveform diagrams of the control method used in the first power conversion direction of the bidirectional isolated multi-stage DC-DC power conversion device with a wide voltage range according to the preferred embodiment of the present invention. Please refer to Figures 2, 4(A) and 4(B) again, for example, when inputting the first input/output side of the bidirectional isolated multi-stage DC-DC power conversion device 10 with a wide voltage range At the time, the third switch S ₃ and the fourth switch S ₄ of the second half-bridge power converter 31 , the fifth switch S ₅ and the sixth switch S _{6 of} the third half-bridge power converter 32 are connected to the The second selection switch 42 is turned off, and controls the operation of the first switch S _{1 of} the first half-bridge power converter 1 (as shown by the switching signal in the upper half of FIG. 4(A) ) and the first switch S 1 of the first half-bridge power converter 1 Two switches S ₂ [as shown by the switching signal in the lower half of Fig. 4(A)] and the first selection switch 41 [as shown by the switching signal in Fig. 4(B)], so that the wide voltage range can be The second input/output side of the bidirectional isolated multi-stage DC-DC power conversion device 10 selectively outputs a low voltage to a high voltage.

Referring to Figures 2 and 4(A), the first switch S ₁ and the second switch S _{2 of} the first half-bridge power converter 1 both use switching with a fixed duty cycle of 0.5. Therefore, the first half-bridge power converter 1 will output a high frequency square wave voltage with a fixed width, and the fixed width high frequency square wave voltage is connected to the first winding 21 of the transformer 2 , and the transformer 2 The second winding 22 and the third winding 23 induce a high-frequency square wave voltage with the same waveform, and the first output DC is generated by the second half-bridge power converter 31 and the third half-bridge power converter 32 respectively. voltage and the second output DC voltage. Assuming that the input voltage is V _in , the turns ratio of the first winding 21 , the second winding 22 and the third winding 23 of the transformer 22 is n ₁ : n ₂ : n ₃ , then the first output DC voltage is V _in * n ₂ /n ₁ , the second output DC voltage is V _in *n ₃ /n ₁ .

Referring to Figures 2 and 4(A) to 4(C), the first output DC voltage and the second output DC voltage are controlled by operation, so as to output two voltage levels to form a multi-level output voltage. The first output DC voltage and the second output DC voltage are selected to form a series supply power, so the sum of the first output DC voltage and the second output DC voltage (V _in *n ₂ /n ₁ +V _in *n3/ n1), or select the output voltage to be the second DC voltage (V _in *n ₃ /n ₁ ).

Figures 5(A) and 5(B) show waveform diagrams of the bidirectional isolated multi-stage DC-DC power conversion device with a wide voltage range using another control method in the second power conversion direction according to the preferred embodiment of the present invention. Please refer to Figures 3, 5(A) and 5(B) again, for example, when the input DC voltage is input to the bidirectional isolated multi-stage DC-DC power conversion device 10 with a wide voltage range When there are two input/output sides, the first switch S ₁ and the second switch S _{2 of} the first half-bridge power converter 1 and the first selection switch 41 are switched off, and the second switch 41 is controlled to operate. The third switch S _{3 of the} half-bridge power converter 31 (as shown by the switching signal in the upper half of Fig. 5(A)) and the fourth switch S ₄ [as shown in the switching signal in the lower half of Fig. 5(A) ] shown], the fifth switch S _{5 of} the third half-bridge power converter 32 [as shown by the switching signal in the upper half of Fig. 5(A)] and the sixth switch S ₆ [as shown in Fig. 5(A) and the second selector switch 42 (shown as the switching signal in Fig. 5(B)), so as to convert the bidirectional isolated multi-stage DC-DC power with a wide voltage range. The first input/output side of the device 10 selectively outputs a fixed voltage.

Refer to Section 3 and 5 (A), FIG., The second half-bridge power converter 31 of the third switch S ₃ and the third half-bridge power converter 32 of the fifth switch S ₅ use the same switching signal [As shown by the switching signal in the upper half of Fig. 5(A)], the fourth switch S _{4 of} the second half-bridge power converter 31 and the sixth switch S of the third half-bridge power converter 32 ₆ All use another same switching signal (as shown in the switching signal in the lower half of Figure 5(A)), and its fixed duty cycle is 0.5 switching.

FIG. 6 shows a schematic diagram of the structure of the bidirectional isolated multi-stage DC-DC power conversion device with a wide voltage range for power conversion in the first power conversion direction according to the second preferred embodiment of the present invention; FIG. 7 shows the second embodiment of the present invention. A schematic diagram of the structure of the bidirectional isolated multi-stage DC-DC power conversion device with a wide voltage range for power conversion in the second power conversion direction according to the preferred embodiment. Referring to FIGS. 6 and 7, compared to the first embodiment, the bidirectional isolated multi-stage DC-DC power conversion device 10a with a wide voltage range according to the second preferred embodiment of the present invention includes a first full-bridge type The power converter 1 a , a transformer 2 , a second full-bridge power converter 31 a , a third full-bridge power converter 32 a , a first selection switch 41 , a second selection switch 42 and a filter circuit 5 .

Please refer to FIG. 6 and FIG. 7, for example, the first full-bridge power converter 1a comprises a first switch [for example: two power electronic switches S _1] and a second switch [for example: two two power electronic switches S _2], and a set of the first capacitor C _1. The first full-bridge power converter 1a can be optionally changed to a half-bridge power converter or other power converters.

Please refer to Figures 6 and 7, for example, the transformer The transformer 2 can be selected from a transformer with three windings, and the transformer 2 includes a primary side and a secondary side, and the primary side has a first winding 21, and the secondary side has a second winding 22 and a third winding twenty three. The first winding 21 of the transformer 2 is properly connected to the AC output terminal of the first full-bridge power converter 1a. In addition, the filter circuit 5 includes an inductor and a capacitor.

Referring to FIGS. 6 and 7 again, for example, the second full-bridge power converter 31a can be optionally changed to a half-bridge power converter or other power converters, and the second full-bridge power converter 31a The device 31a has a third switch (eg, two power electronic switches) S ₃ , a fourth switch (eg, two power electronic switches) S ₄ and a second capacitor bank C ₂ . The AC input of the second full-bridge power converter 31a is connected to the second winding 22 of the transformer 2, and the second full-bridge power converter 31a has a first DC positive output terminal and a first direct current flow negative output terminal, and the first positive DC output terminal and a first negative DC output terminal of the second capacitor is connected in parallel to form a set of C ₂ a first output DC voltage.

Referring to FIGS. 6 and 7 again, for example, the third full-bridge power converter 32a can be optionally changed to a half-bridge power converter or other power converters, and the third full-bridge power converter The device 32a has a fifth switch (eg, two power electronic switches) S ₅ , a sixth switch (eg, two power electronic switches) S ₆ and a third capacitor bank C ₃ . The AC input of the third full-bridge power converter 32a is connected to the third winding 23 of the transformer 2, and the third full-bridge power converter 32a has a second DC positive output terminal and a second DC negative an output terminal, and the second DC output terminal and a second positive DC negative output terminal connected in parallel to the third capacitor C ₃ form a set of second output DC voltage, and the third full-bridge 32a of the second power converter The DC positive output terminal is connected to the first DC negative output terminal of the second full-bridge power converter 31a.

Referring again to Figures 6 and 7, for example, the first selector switch (eg, a power electronic switch) 41 has a first terminal (input /output terminal] and a second terminal [input/output terminal], and the first terminal of the first selection switch 41 is connected to the first DC positive output terminal of the first full-bridge power converter 31a.

Please refer to FIGS. 6 and 7 again. For example, the second selector switch (eg, power electronic switch) 42 has a first terminal (input/output terminal) and a second terminal (input/output terminal) , and the first terminal of the second selection switch 42 is connected to the first DC negative output terminal of the second full-bridge power converter 31a and the second DC positive output terminal of the third full-bridge power converter 32a.

Please refer to FIGS. 6 and 7 again, for example, the filter circuit 5 is connected to the second terminal of the first selection switch 41 , the second terminal of the second selection switch 42 and the third full-bridge power converter The second DC negative output terminal of 32a.

Please refer to Figures 6, 4(A) and 4(B) again, for example, when inputting the first input/output side of the bidirectional isolated multi-stage DC-DC power conversion device 10a with a wide voltage range when the second full-bridge power converter 31a of the third switch and a fourth switch S ₃ S _4, the third full-bridge power converter 32a of the fifth and sixth switches S ₅ and S ₆ switches the The second selection switch 42 is turned off, and controls the operation of the first switch S _{1 of} the first full-bridge power converter 1a (as shown by the switching signal in the upper half of Fig. 4(A)) and the first switch S 1 of the first full-bridge power converter 1a. Two switches S ₂ [as shown by the switching signal in the lower half of Fig. 4(A)] and the first selection switch 41 [as shown by the switching signal in Fig. 4(B)], so that the wide voltage range can be The second input/output side of the bidirectional isolated multi-stage DC-DC power conversion device 10a selectively outputs a low voltage to a high voltage.

Please refer to Figures 7, 5(A) and 5(B) again, for example, when the input DC voltage is input to the bidirectional isolated multi-stage DC-DC power conversion device 10a with a wide voltage range, the first When there are two input/output sides, the first switch S ₁ and the second switch S _{2 of} the first full-bridge power converter 1a and the first selection switch 41 are turned off, and the second switch 41 is controlled to operate. [switching signal as in the first half of the 5 (A)] the full-bridge as shown in FIG power converter 31a of the third switch S ₃ and a fourth switch S ₄ as in the first [5 (A) the switching signal of the lower half of FIG. ], the third full-bridge power converter of the fifth switch S ₅ [32a as in the first 5 (A) shown in FIG upper half of the switching signal shown in the sixth switch S _6] and [as described in section 5 (A) and the second selector switch 42 (shown as the switching signal in Fig. 5(B)), so as to convert the bidirectional isolated multi-stage DC-DC power with a wide voltage range. The first input/output side of the device 10a selectively outputs a fixed voltage.

The aforementioned preferred embodiment is only an example of the present invention and its technical features, and the technology of this embodiment can still be implemented in various substantially equivalent modifications and/or alternative ways; therefore, the scope of the right of the present invention is subject to the appended patent application The scope defined by the scope shall prevail. The copyright in this case is restricted to be used for the purposes of the ROC patent application.

10‧‧‧Bidirectional isolated multi-stage DC-DC power conversion device with wide voltage range

1‧‧‧First Half-Bridge Power Converter

2‧‧‧Transformer

21‧‧‧First winding

22‧‧‧Second winding

23‧‧‧Third winding

31‧‧‧Second half-bridge power converter

32‧‧‧Third Half-Bridge Power Converter

41‧‧‧First selector switch

42‧‧‧Second selector switch

5‧‧‧Filter circuit

Claims (24)

A bidirectional isolated multi-stage DC-DC power conversion device with a wide voltage range, comprising: a DC/DC converter, comprising a first input/output side and a second input/output side, comprising: a a first power converter, which is arranged between the first input/output side and the second input/output side of the DC/DC converter; a transformer, which is arranged in the DC/DC converter, and the transformer includes a primary side and secondary side, and the primary side of the transformer has a first winding, and the first winding of the transformer is connected to the first power converter, and the secondary side of the transformer has a second winding and a first winding Three windings; a second power converter whose input is connected to the second winding of the transformer, and the second power converter has a first DC positive output terminal and a first DC negative output terminal; a third power a converter, the input of which is connected to the third winding of the transformer, the third power converter has a second DC positive output terminal and a second DC negative output terminal, and the second DC positive output of the third power converter The terminal is connected to the first DC negative output terminal of the second power converter; a first selection switch is connected to the first DC positive output terminal of the second power converter; a second selection switch is connected to the first DC negative output terminal of the second power converter and the second DC positive output terminal of the third power converter; and a filter circuit connected to the output terminal of the first selection switch and the second selection switch The output terminal of the third power converter and the second DC negative output terminal of the third power converter; wherein when a high-voltage DC input is input to the first input/output side of the DC/DC converter, the second power converter, the first power converter The three power converters and the second selection switch are cut off, and the first power converter and the first selection switch are controlled to be operated, so that a low voltage is selected and output from the second input/output side of the DC/DC converter to a high voltage; or When the input DC voltage is input to the second input/output side of the DC/DC converter, the first power converter and the first selection switch are cut off, and the second power converter, The third power converter and the second selection switch are used to select and output a fixed voltage from the first input/output side of the DC/DC converter. The bidirectional isolated multi-stage DC-DC power conversion device with wide voltage range according to the claim 1, wherein the first power converter is selected from a full-bridge power converter or a half-bridge power converter . The bidirectional isolated multi-stage DC-DC power conversion device with a wide voltage range as described in claim 1, wherein the second power converter and the third power converter are selected from a full-bridge power converter or Half-bridge power converter. The bidirectional isolated multi-stage DC-DC power conversion device with wide voltage range according to the claim 1 of the claimed scope, wherein when the second power converter is selected as a half-bridge power converter, the second power converter The first DC positive output terminal and the first DC negative output terminal of the device are connected in parallel with a first capacitor bank and a second capacitor bank to form a first output DC voltage. The bidirectional isolated multi-stage DC-DC power conversion device with a wide voltage range according to item 1 of the application scope, wherein when the third power converter is selected as a half-bridge power converter, the third power converter The second DC positive output terminal and the second DC negative output terminal of the device are connected in parallel with a third capacitor bank and a fourth capacitor bank to form a second output DC voltage. The bidirectional isolated multi-stage DC-DC power conversion device with a wide voltage range described in claim 1, wherein when the second power converter is selected as a full-bridge power converter, the second power The first DC positive output terminal and the first DC negative output terminal of the converter are connected in parallel with a first capacitor bank to form a first output DC voltage. The bidirectional isolated multi-stage DC-DC power conversion device with a wide voltage range according to claim 1, wherein when the third power converter is selected as a full-bridge power converter, the third power Converter No. 1 The two DC positive output terminals and the second DC negative output terminal are connected in parallel with a second capacitor bank to form a second output DC voltage. The bidirectional isolated multi-stage DC-DC power conversion device with a wide voltage range according to the claim 1 of the scope of the application, wherein the first DC positive output terminal and the first DC power of the second power converter are controlled by operation The negative output terminal is connected in parallel with a first capacitor bank to form a first output DC voltage, and the second DC positive output terminal and the second DC negative output terminal of the third power converter are connected in parallel with a second capacitor bank to form a first output DC voltage. A second output DC voltage is formed so as to output two voltage levels to form a multi-level output voltage. A bidirectional isolated multi-stage DC-DC power conversion method with a wide voltage range, comprising: providing a first power converter, a transformer, a second power converter, and a third power in a DC/DC converter converter, a first selection switch, a second selection switch and a filter circuit, and the DC/DC converter includes a first input/output side and a second input/output side; the first power converter connected to an input DC voltage source; the primary side of the transformer has a first winding, and the first winding of the primary side of the transformer is connected to an AC output end of the first power converter, and the secondary side of the transformer is The side has a second winding and a third winding; the input of the second power converter is connected to the second winding of the secondary side of the transformer, and the second power converter has a first DC positive output terminal and A first DC negative output terminal, and the first DC positive output terminal and the first DC negative output terminal form a first output DC voltage; the input of the third power converter is connected to the secondary of the transformer the third winding on the side, and the third power converter has a second DC positive output terminal and a second DC negative output terminal, and the second DC positive output terminal and the second DC negative output terminal form a second output DC voltage, and the second DC positive output terminal of the third power converter is connected to the first DC negative output terminal of the second power converter; the first selection switch is connected to the first DC power converter of the second power converter. straight a positive output terminal of the current; the second selection switch is connected to the first DC negative output terminal of the second power converter and the second DC positive output terminal of the third power converter; the filter circuit is connected to the first DC power converter The output terminal of the selection switch, the output terminal of the second selection switch and the second DC negative output terminal of the third power converter; when a high voltage DC input is input to the first input/output side of the DC/DC converter, the The second power converter, the third power converter and the second selection switch are cut off, and the first power converter and the first selection switch are controlled to operate so that the second power converter of the DC/DC converter can operate the switch. The input/output side selects to output a low voltage to a high voltage. The bidirectional isolated multi-stage DC-DC power conversion method with a wide voltage range according to claim 9, wherein the first power converter is selected from a half-bridge power converter or a full-bridge power converter . The bidirectional isolated multi-stage DC-DC power conversion method with wide voltage range described in claim 9, wherein the second power converter and the third power converter are selected from a half-bridge power converter or a Full bridge power converter. The bidirectional isolated multi-stage DC-DC power conversion method with a wide voltage range described in claim 9, wherein when the second power converter is selected as a half-bridge power converter, the second power converter is The first DC positive output terminal and the first DC negative output terminal of the device are connected in parallel with a first capacitor bank and a second capacitor bank to form the first output DC voltage. The bidirectional isolated multi-stage DC-DC power conversion method with a wide voltage range described in claim 9, wherein when the third power converter is selected as a half-bridge power converter, the third power conversion The second DC positive output terminal and the second DC negative output terminal of the device are connected in parallel with a third capacitor bank and a fourth capacitor bank to form the second output DC voltage. The bidirectional isolated multi-stage DC-DC power conversion method with a wide voltage range described in claim 9, wherein when the second power converter is selected as a full-bridge power converter, the second power Converter No. 1 The DC positive output terminal and the first DC negative output terminal are connected in parallel with a first capacitor group to form the first output DC voltage. The bidirectional isolated multi-stage DC-DC power conversion method with a wide voltage range described in claim 9, wherein when the third power converter is selected as a full-bridge power converter, the third power converter is The second DC positive output terminal and the second DC negative output terminal of the converter are connected in parallel with a second capacitor bank to form the second output DC voltage. The bidirectional isolated multi-stage DC-DC power conversion method with a wide voltage range described in claim 9, wherein the first output DC voltage and the second output DC voltage are controlled by operation, so as to output two voltages layers to form a multi-level output voltage. A bidirectional isolated multi-stage DC-DC power conversion method with a wide voltage range, comprising: providing a first power converter, a transformer, a second power converter, and a third power in a DC/DC converter converter, a first selection switch, a second selection switch and a filter circuit, and the DC/DC converter includes a first input/output side and a second input/output side; the first power converter connected to an input DC voltage source; the primary side of the transformer has a first winding, and the first winding of the primary side of the transformer is connected to an AC output end of the first power converter, and the secondary side of the transformer is The side has a second winding and a third winding; the input of the second power converter is connected to the second winding of the secondary side of the transformer, and the second power converter has a first DC positive output terminal and A first DC negative output terminal, and the first DC positive output terminal and the first DC negative output terminal form a first output DC voltage; the input of the third power converter is connected to the secondary of the transformer the third winding on the side, and the third power converter has a second DC positive output terminal and a second DC negative output terminal, and the second DC positive output terminal and the second DC negative output terminal form a second output DC voltage, and the second DC positive output terminal of the third power converter is connected to the first power converter of the second power converter DC negative output terminal; the first selection switch is connected to the first DC positive output terminal of the second power converter; the second selection switch is connected to the first DC negative output terminal of the second power converter and the second DC positive output terminal of the third power converter; the filter circuit is connected to the output terminal of the first selection switch, the output terminal of the second selection switch and the second DC negative output terminal of the third power converter; When the input DC voltage is input to the second input/output side of the DC/DC converter, the first power converter and the first selection switch are cut off, and the second power converter, the The third power converter and the second selection switch are used to select and output a fixed voltage from the first input/output side of the DC/DC converter. The bidirectional isolated multi-stage DC-DC power conversion method with a wide voltage range according to claim 17, wherein the first power converter is selected from a half-bridge power converter or a full-bridge power converter . The bidirectional isolated multi-stage DC-DC power conversion method with a wide voltage range described in claim 17, wherein the second power converter and the third power converter are selected from a half-bridge power converter or a Full bridge power converter. The bidirectional isolated multi-stage DC-DC power conversion method with a wide voltage range described in claim 17, wherein when the second power converter is selected as a half-bridge power converter, the second power converter The first DC positive output terminal and the first DC negative output terminal of the device are connected in parallel with a first capacitor bank and a second capacitor bank to form the first output DC voltage. The bidirectional isolated multi-stage DC-DC power conversion method with a wide voltage range according to the claim 17, wherein when the third power converter is selected as a half-bridge power converter, the third power converter The second DC positive output terminal and the second DC negative output terminal of the device are connected in parallel with a third capacitor bank and a fourth capacitor bank to form the second output DC voltage. Bidirectional isolation with wide voltage range according to Item 17 of the scope of the application An off-type multi-stage DC-DC power conversion method, wherein when the second power converter is selected as a full-bridge power converter, the first DC positive output terminal and the first DC negative output of the second power converter are The output terminal is connected in parallel with a first capacitor bank to form the first output DC voltage. The bidirectional isolated multi-stage DC-DC power conversion method with a wide voltage range described in claim 17, wherein when the third power converter is selected as a full-bridge power converter, the third power converter is The second DC positive output terminal and the second DC negative output terminal of the converter are connected in parallel with a second capacitor bank to form the second output DC voltage. The bidirectional isolated multi-stage DC-DC power conversion method with a wide voltage range described in claim 17, wherein the first output DC voltage and the second output DC voltage are controlled by operation, so as to output two voltages layers to form a multi-level output voltage.

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