Direct-current transformation circuit and system
Through the combination of the switching DCDC module and compensation capacitor, the problem that the adjustable DC transformer cannot match the load and current distortion of different voltage levels is solved, and a wider load adaptability and current distortion improvement is achieved.
Patent Information
- Application Number
- CN202510667828.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-22
- Publication Date
- 2025-08-12
AI Technical Summary
The output voltage of the secondary winding of the adjustable DC transformer is fixed, and it cannot flexibly match loads of different voltage levels. The existence of stray inductance causes resonant current distortion, affecting the soft switching effect of the switch tube.
By switching the first DCDC module, the second DCDC module, and the third DCDC module, the output voltage of the secondary winding of the transformer is changed, and an input compensation capacitor is selected in the corresponding DCDC module for port impedance compensation, thereby improving current distortion.
The voltage matching for different loads is achieved, the current distortion is reduced, and the soft switching performance of the switching tube is improved.
Smart Images
Figure CN120474347A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of voltage transformation, and in particular to a direct current voltage transformation circuit and system. Background Art
[0002] Adjustable DC transformers are a key component in designing efficient power distribution systems, and their research is gaining increasing attention. They are widely used in hybrid power distribution systems to control power flows between different power sources, storage elements, or loads. However, the three ports of an adjustable DC transformer (one inverter output port and two rectifier output ports) have different parameter values. Furthermore, stray inductance exists in each of these ports. This stray inductance participates in the resonant network, causing distortion in the resonant current and potentially rendering the soft switching (zero-current shutdown) of the rectifier-side switches ineffective. Therefore, port impedance compensation is urgently needed to improve current distortion. Furthermore, the output voltage of the secondary winding of existing adjustable DC transformers is fixed, making it inflexible for loads with varying voltage levels. Summary of the Invention
[0003] The present invention aims to provide a DC voltage conversion circuit and system. This solution changes the voltage output by the secondary winding of a transformer by switching a first DC-DC module, a second DC-DC module, and a third DC-DC module, thereby matching a wider variety of loads. Furthermore, this solution selectively inserts corresponding compensation capacitors into the circuits corresponding to the DC-DC modules to compensate for port impedance and improve current distortion.
[0004] To solve the above technical problems, the present invention provides a DC voltage conversion circuit, comprising an inverter circuit and a transformer connected to the output end of the inverter circuit, and further comprising: a first rectifier circuit, a second rectifier circuit, a first compensation capacitor, a second compensation capacitor, a third compensation capacitor, a first DCDC module, a second DCDC module, a third DCDC module, and a controller;
[0005] The first DCDC module is connected in series in a loop of the inverter circuit, the primary winding of the transformer, the first secondary winding of the transformer, and the first rectifier circuit;
[0006] The second DCDC module is connected in series in a loop of the inverter circuit, the primary winding of the transformer, the second secondary winding of the transformer, and the second rectifier circuit;
[0007] The third DCDC module is connected in series in a loop of the third compensation capacitor, the first secondary winding of the transformer, the first rectifier circuit, the second secondary winding of the transformer, and the second rectifier circuit;
[0008] The first compensation capacitor is connected in series in a loop of the inverter circuit, the primary winding of the transformer, the first secondary winding of the transformer, and the first rectifier circuit;
[0009] The second compensation capacitor is connected in series in a loop of the inverter circuit, the primary winding of the transformer, the second secondary winding of the transformer, and the second rectifier circuit;
[0010] The third compensation capacitor is connected in series in a loop of the first secondary winding of the transformer, the first rectifier circuit, the second secondary winding of the transformer, and the second rectifier circuit;
[0011] The controller is configured to selectively control the first DCDC module, the second DCDC module, or the third DCDC module to be put into operation, and selectively control the first compensation capacitor, the second compensation capacitor, or the third compensation capacitor to be put into operation.
[0012] Optionally, the capacitance of the first compensation capacitor, the first leakage inductance of the first secondary winding of the transformer, and the resonant period of the primary winding of the transformer satisfy a first preset size relationship.
[0013] Optionally, the capacitance of the second compensation capacitor, the second leakage inductance of the second secondary winding of the transformer, and the resonant period of the primary winding of the transformer satisfy a second preset size relationship.
[0014] Optionally, the capacitance of the third compensation capacitor, the first leakage inductance of the first secondary winding of the transformer, and the resonant period of the second secondary winding of the transformer satisfy a third preset size relationship.
[0015] Optionally, also include:
[0016] A first protection device, wherein the first protection device is connected in series in a loop of the first DCDC module, the inverter circuit, the primary winding of the transformer, the first compensation capacitor, the first secondary winding of the transformer, and the first rectifier circuit, and is configured to disconnect when an overvoltage and / or overcurrent condition occurs in the loop where the first protection device is located.
[0017] Optionally, also include:
[0018] A second protection device, wherein the second protection device is connected in series in the loop of the second DCDC module, the inverter circuit, the primary winding of the transformer, the second compensation capacitor, the second secondary winding of the transformer and the second rectifier circuit, and is used to disconnect when an overvoltage and / or overcurrent condition occurs in the loop where the second protection device is located.
[0019] Optionally, also include:
[0020] A third protection device, wherein the third protection device is connected in series in the loop of the third DCDC module, the third compensation capacitor, the first secondary winding of the transformer, the first rectifier circuit, the second secondary winding of the transformer and the second rectifier circuit, and is used to disconnect when an overvoltage and / or overcurrent condition occurs in the loop where the third protection device is located.
[0021] Optionally, the controller is further configured to:
[0022] After controlling the first DCDC module to be put into operation, the duty cycle of the switch tube in the first DCDC module is selected to be adjusted; after controlling the second DCDC module to be put into operation, the duty cycle of the switch tube in the second DCDC module is selected to be adjusted; after controlling the third DCDC module to be put into operation, the duty cycle of the switch tube in the third DCDC module is selected to be adjusted.
[0023] To solve the above technical problems, the present invention further provides a DC conversion system, comprising: a power supply, a load, and the DC conversion circuit as described above, wherein the DC conversion circuit is connected to the power supply and the load respectively.
[0024] The present invention aims to provide a DC voltage conversion circuit and system. Considering that when the load connected to the secondary winding of the transformer changes, the voltage required by the load also changes, this solution changes the voltage output by the secondary winding of the transformer by switching on and off a first DC-DC module, a second DC-DC module, and a third DC-DC module, thereby matching a wider variety of loads. Furthermore, considering that the loop containing the winding of the transformer connected to a corresponding DC-DC module has lower power than the loop containing the winding of the transformer not connected to the corresponding DC-DC module, this solution also selectively implements corresponding compensation capacitors in the loop containing the corresponding DC-DC module to perform port impedance compensation and improve current distortion. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.
[0026] Figure 1 A schematic structural diagram of a DC transformer circuit provided by the present invention;
[0027] Figure 2 A schematic structural diagram of a novel DC transformer circuit provided by the present invention;
[0028] Figure 3A schematic structural diagram of another novel DC transformer circuit provided by the present invention;
[0029] Figure 4 A schematic structural diagram of another novel DC transformer circuit provided by the present invention;
[0030] Figure 5 A schematic structural diagram of another DC transformer circuit provided by the present invention;
[0031] Figure 6 A waveform diagram of a three-port DC transformer circuit without port impedance compensation provided by the present invention;
[0032] Figure 7 This is a waveform diagram of a novel DC transformer circuit using port impedance compensation provided by the present invention. DETAILED DESCRIPTION
[0033] The core of the present invention is to provide a DC voltage conversion circuit and system. This solution changes the voltage output by the secondary winding of the transformer by switching the first, second, and third DC-DC modules, thereby matching a wider variety of loads. In addition, this solution also selectively inputs corresponding compensation capacitors into the circuit where the corresponding DC-DC module is located to compensate for port impedance and improve current distortion.
[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.
[0035] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a DC voltage conversion circuit provided by the present invention. The DC voltage conversion circuit includes an inverter circuit 1 and a transformer 2 connected to the output end of the inverter circuit 1. It also includes: a first rectifier circuit 3, a second rectifier circuit 4, a first compensation capacitor 5, a second compensation capacitor 6, a third compensation capacitor 7, a first DC-DC module 8, a second DC-DC module 9, a third DC-DC module 10, and a controller 11.
[0036] The first DCDC module 8 is connected in series in the loop of the inverter circuit 1, the primary winding of the transformer 2, the first secondary winding of the transformer 2 and the first rectifier circuit 3;
[0037] The second DCDC module 9 is connected in series to the loop of the inverter circuit 1, the primary winding of the transformer 2, the second secondary winding of the transformer 2 and the second rectifier circuit 4;
[0038] The third DCDC module 10 is connected in series in the loop of the first secondary winding of the transformer 2, the first rectifier circuit 3, the second secondary winding of the transformer 2 and the second rectifier circuit 4;
[0039] The first compensation capacitor 5 is connected in series in the loop of the inverter circuit 1, the primary winding of the transformer 2, the first secondary winding of the transformer 2 and the first rectifier circuit 3;
[0040] The second compensation capacitor 6 is connected in series in the loop of the inverter circuit 1, the primary winding of the transformer 2, the second secondary winding of the transformer 2 and the second rectifier circuit 4;
[0041] The third compensation capacitor 7 is connected in series in the loop of the first secondary winding of the transformer 2, the first rectifier circuit 3, the second secondary winding of the transformer 2 and the second rectifier circuit 4;
[0042] The controller 11 is used to selectively control the first DCDC module 8, the second DCDC module 9, or the third DCDC module 10 to be put into operation, and selectively control the first compensation capacitor 5, the second compensation capacitor 6, or the third compensation capacitor 7 to be put into operation.
[0043] In the present invention, when the load connected to the secondary winding of the transformer 2 changes, the voltage value required by the load will also change. Therefore, the present application sets a controller 11, a first DCDC module 8, a second DCDC module 9, and a third DCDC module 10, and controls the switching of the first DCDC module 8, the second DCDC module 9, and the third DCDC module 10 by the controller 11, so as to change the output voltage of the circuit where the secondary winding of the transformer 2 is located without the DCDC module in the circuit by the DCDC module in the circuit, thereby matching more types of loads; in addition, considering the voltage transformer in the DC transformer circuit There is stray inductance in the three ports of the transformer 2, and it participates in the resonant network, causing the resonant current to be distorted, resulting in the failure of the soft switching of the switch tube on the rectifier side. Therefore, this solution adds a first compensation capacitor 5, a second compensation capacitor 6, and a third compensation capacitor 7. Because the power of the loop where the secondary winding of the transformer 2 with the DCDC module is located is smaller than that of the loop where the secondary winding of the transformer 2 without the DCDC module is located, the corresponding compensation capacitor is added to the loop where the secondary winding of the transformer 2 with the DCDC module is located, so that the port impedance of the transformer 2 can be accurately compensated to eliminate the current distortion in the loop.
[0044] This embodiment provides a DC transformer circuit. Considering that when the load connected to the secondary winding of the transformer 2 changes, the voltage required by the load also changes, this solution changes the voltage output by the secondary winding of the transformer 2 by switching the first DCDC module 8, the second DCDC module 9, and the third DCDC module 10, thereby matching a wider variety of loads. In addition, considering that the loop containing the winding of the transformer 2 connected to the corresponding DCDC module has lower power than the loop containing the winding of the transformer 2 not connected to the corresponding DCDC module, this solution also selects to implement corresponding compensation capacitors in the loop containing the corresponding DCDC module to perform port impedance compensation and improve current distortion.
[0045] Based on the above embodiment:
[0046] As an optional embodiment, the capacitance of the first compensation capacitor 5 , the first leakage inductance of the first secondary winding of the transformer 2 , and the resonance period of the primary winding of the transformer 2 satisfy a first preset size relationship.
[0047] In the present invention, after the first DCDC module 8 is put into operation, considering the actual desire to eliminate the influence of the resonant current as much as possible, it is necessary to make the resonant period of the loop where the primary winding of the transformer 2 is located approximately equal to the resonant period of the loop where the secondary winding of the transformer 2 is located after the first DCDC module 8 is put into operation. The resonant period of the loop where the first secondary winding of the transformer 2 is located is related to the capacitance of the first compensation capacitor 5 and the first leakage inductance of the first secondary winding of the transformer 2. Therefore, the capacitance of the first compensation capacitor 5 can be determined according to the first leakage inductance of the first secondary winding of the transformer 2 and the resonant period of the primary winding of the transformer 2. By putting in the first compensation capacitor 5 with the corresponding capacitance, the influence of the resonant current can be eliminated as much as possible.
[0048] It should be noted that, ideally, the resonant period of the loop where the primary winding of the transformer 2 is located should be equal to the resonant period of the loop where the secondary winding of the transformer 2 is located after the first DCDC module 8 is put into operation. The capacitance of the first compensation capacitor 5 is determined by the formula: , , represents the resonant period of the primary winding of transformer 2, represents the resonant period of the first secondary winding of transformer 2, represents the first leakage inductance of the first secondary winding of transformer 2, represents the capacitance of the first compensation capacitor 5, Indicates the preset resonant period error.
[0049] As an optional embodiment, the capacitance of the second compensation capacitor 6 , the second leakage inductance of the second secondary winding of the transformer 2 , and the resonance period of the primary winding of the transformer 2 satisfy a second preset size relationship.
[0050] In the present invention, after the second DCDC module 9 is put into operation, considering the actual desire to eliminate the influence of the resonant current as much as possible, it is necessary to make the resonant period of the loop where the primary winding of the transformer 2 is located approximately equal to the resonant period of the loop where the secondary winding of the transformer 2 is located after the second DCDC module 9 is put into operation. The resonant period of the loop where the second secondary winding of the transformer 2 is located is related to the capacitance of the second compensation capacitor 6 and the second leakage inductance of the second secondary winding of the transformer 2. Therefore, the capacitance of the second compensation capacitor 6 can be determined according to the second leakage inductance of the second secondary winding of the transformer 2 and the resonant period of the primary winding of the transformer 2. By putting in the second compensation capacitor 6 with the corresponding capacitance, the influence of the resonant current can be eliminated as much as possible.
[0051] It should be noted that, ideally, the resonant period of the loop where the primary winding of the transformer 2 is located should be equal to the resonant period of the loop where the second secondary winding of the transformer 2 is located after the second DCDC module 9 is put into operation. The capacitance of the second compensation capacitor 6 is determined by the formula: , , represents the resonant period of the primary winding of transformer 2, represents the resonant period of the first secondary winding of transformer 2, represents the second leakage inductance of the second secondary winding of transformer 2, represents the capacitance of the second compensation capacitor 6, Indicates the preset resonant period error.
[0052] As an optional embodiment, the capacitance of the third compensation capacitor 7 , the first leakage inductance of the first secondary winding of the transformer 2 , and the resonant period of the second secondary winding of the transformer 2 satisfy a third preset size relationship.
[0053] In the present invention, after the third DCDC module 10 is put into operation, considering the actual desire to eliminate the influence of the resonant current as much as possible, it is necessary to make the resonant period of the loop where the primary winding of the transformer 2 is located approximately equal to the resonant period of the loop where the secondary winding of the transformer 2 is located after the third DCDC module 10 is put into operation. The resonant period of the loop where the first secondary winding of the transformer 2 is located is related to the capacitance of the third compensation capacitor 7 and the first leakage inductance of the first secondary winding of the transformer 2. Therefore, the capacitance of the third compensation capacitor 7 can be determined according to the first leakage inductance of the first secondary winding of the transformer 2 and the resonant period of the second secondary winding of the transformer 2. By putting in the third compensation capacitor 7 with the corresponding capacitance, the influence of the resonant current can be eliminated as much as possible.
[0054] It should be noted that, ideally, the resonant period of the loop where the second secondary winding of the transformer 2 is located should be equal to the resonant period of the loop where the first secondary winding of the transformer 2 is located after the third DCDC module 10 is put into operation. The capacitance value of the third compensation capacitor 7 is determined by the formula: , , represents the resonant period of the primary winding of transformer 2, represents the resonant period of the first secondary winding of transformer 2, represents the first leakage inductance of the first secondary winding of transformer 2, represents the capacitance of the third compensation capacitor 7, Indicates the preset resonant period error.
[0055] As an optional embodiment, the method further includes:
[0056] The first protection device is connected in series in the loop of the first DCDC module 8, the inverter circuit 1, the primary winding of the transformer 2, the first compensation capacitor 5, the first secondary winding of the transformer 2 and the first rectifier circuit 3, and is used to disconnect when an overvoltage and / or overcurrent condition occurs in the loop where the first protection device is located.
[0057] In the present invention, considering that the DC transformer circuit may experience overvoltage and / or overcurrent conditions in actual operation, which may easily burn out the electronic components in the circuit, a first protection device is added to the loop where the first DCDC module 8 is located in this solution. The first protection device can actively disconnect when an overvoltage and / or overcurrent condition occurs in the loop, thereby protecting the safety of the electronic components in the DC transformer circuit.
[0058] It should be noted that, in actual applications, the protection device may be a circuit breaker or a protection device such as a fuse, and this application does not make any special limitations thereto.
[0059] As an optional embodiment, the method further includes:
[0060] The second protection device is connected in series in the loop of the second DCDC module 9, the inverter circuit 1, the primary winding of the transformer 2, the second compensation capacitor 6, the second secondary winding of the transformer 2 and the second rectifier circuit 4, and is used to disconnect when an overvoltage and / or overcurrent condition occurs in the loop where the second protection device is located.
[0061] In the present invention, considering that the DC transformer circuit may experience overvoltage and / or overcurrent conditions in actual operation, which may easily burn out the electronic components in the circuit, a second protection device is added to the loop where the second DCDC module 9 is located in this solution. The second protection device can actively disconnect when an overvoltage and / or overcurrent condition occurs in the loop, thereby protecting the safety of the electronic components in the DC transformer circuit.
[0062] As an optional embodiment, the method further includes:
[0063] The third protection device is connected in series in the loop of the third DCDC module 10, the third compensation capacitor 7, the first secondary winding of the transformer 2, the first rectifier circuit 3, the second secondary winding of the transformer 2 and the second rectifier circuit 4, and is used to disconnect when an overvoltage and / or overcurrent condition occurs in the loop where the third protection device is located.
[0064] In the present invention, considering that the DC transformer circuit may experience overvoltage and / or overcurrent conditions during actual operation, which may easily burn out the electronic components in the circuit, a third protection device is added to the loop where the third DCDC module 10 is located in this solution. The third protection device can actively disconnect when an overvoltage and / or overcurrent condition occurs in the loop, thereby protecting the safety of the electronic components in the DC transformer circuit.
[0065] As an optional embodiment, the controller 11 is further configured to:
[0066] After controlling the first DCDC module 8 to be put into operation, the duty cycle of the switch tube in the first DCDC module 8 is selected to be adjusted; or after controlling the second DCDC module 9 to be put into operation, the duty cycle of the switch tube in the second DCDC module 9 is selected to be adjusted; or after controlling the third DCDC module 10 to be put into operation, the duty cycle of the switch tube in the third DCDC module 10 is selected to be adjusted.
[0067] In the present invention, considering that the voltage required by the load changes when the load connected to the secondary winding of transformer 2 changes, this solution adds a first DCDC module 8 and a second DCDC module 9. Under the control of a controller 11, the first DCDC module 8 is selectively switched into the loop of the inverter circuit 1, the primary winding of transformer 2, the first capacitor module, the first secondary winding of transformer 2, and the first rectifier circuit 3, or the second DCDC module 9 is switched into the loop of the inverter circuit 1, the primary winding of transformer 2, the second capacitor module, the second secondary winding of transformer 2, and the second rectifier circuit 4. This changes the voltage output by the secondary winding of the unswitched DCDC module, thereby matching a wider variety of loads. Furthermore, because the voltage ratio between the circuit containing the primary winding of transformer 2 and the circuit containing the secondary winding connected to the DCDC module is equal to the power ratio between the two circuits, the power of the circuit containing the secondary winding of transformer 2 can be reduced by switching the DCDC module and changing the duty cycle of the switch within the DCDC module, thereby reducing the power consumption of the circuit containing the secondary winding of transformer 2. In addition, considering that when the load connected to the secondary winding of the transformer 2 changes, the voltage value required by the load will also change, the present application will control the third DCDC module 10 to be switched into the loop where the first secondary winding of the transformer 2 and the second secondary winding of the transformer 2 are located through the control of the controller 11, and then change the voltage output by the secondary winding of the transformer 2 by switching the DCDC module and changing the duty cycle of the switching tube in the DCDC module, thereby matching more types of loads.
[0068] It should also be noted that if Figure 2 As shown, the non-isolated D2D in the auxiliary switch network is the first DCDC module 8, D2A is the first rectifier circuit 3, wherein the positive output terminal of the non-isolated D2D is connected to the positive input terminal of the primary high-frequency switch network (inverter circuit 1), and the negative output terminal of the non-isolated D2D is connected to the negative input terminal of the primary high-frequency switch network (inverter circuit 1), wherein Va is the input voltage of the non-isolated D2D, Vcdc is the output voltage of the non-isolated D2D, and Vin is the power supply voltage. At this time, Vp=Vin+Vcdc, so Vp increases. At this time, according to the turns ratio of the transformer 2, it can be seen that when Vp increases, Vo and Va will also increase; similarly, if Figure 3As shown, the non-isolated D2D in the auxiliary switch network is the second DC-DC module 9, and D2A is the second rectifier circuit 4. When the positive output of the non-isolated D2D is connected to the negative input of the primary high-frequency switch network (inverter circuit 1), and the negative output of the non-isolated D2D is connected to the positive input of the primary high-frequency switch network (inverter circuit 1), Vp = Vin - Vcdc, so Vp decreases. Based on the turns ratio of transformer 2, it can be seen that when Vp decreases, Vo and Va also decrease. The specific voltage change is related to the duty cycle of the switch in the non-isolated D2D.
[0069] It should also be noted that if Figure 4 As shown, the non-isolated D2D in the auxiliary switch network is the third DCDC module 10, D2A is the first rectifier circuit 3 or the second rectifier circuit 4, wherein the positive output terminal of the non-isolated D2D is connected to the positive output terminal of the secondary high-frequency switch network (the second rectifier circuit 4 or the first rectifier circuit 3), and the negative output terminal of the non-isolated D2D is connected to the negative output terminal of the secondary high-frequency switch network (the second rectifier circuit 4 or the first rectifier circuit 3), wherein Va is the input voltage of the non-isolated D2D, and Vcdc is the output voltage of the non-isolated D2D. At this time, Vo=Vs+Vcdc, so Vo increases, that is, the output voltage of the transformer 2 increases, which is convenient for powering a large voltage load; similarly, as Figure 5 As shown, when the positive output of the non-isolated D2D is connected to the negative output of the secondary-side high-frequency switching network (second rectifier circuit 4 or first rectifier circuit 3), and the negative output of the non-isolated D2D is connected to the positive output of the secondary-side high-frequency switching network (second rectifier circuit 4 or first rectifier circuit 3), Vo = Vs - Vcdc. Therefore, Vo decreases, and the output voltage of transformer 2 decreases, making it easier to power low-voltage loads. The specific voltage change is related to the duty cycle of the switch in the non-isolated D2D.
[0070] It should also be noted that Figure 2-5 The non-isolated D2D in this system includes conventional non-isolated DC / DC converters, including but not limited to topologies such as Buck, Boost, Cuk, Buck-Boost, and Sepic. The auxiliary network voltage Vcdc has two polarities. The primary-side switching network (inverter circuit 1) includes but is not limited to full-bridge inverter circuit 1, half-bridge inverter circuit 1, and other conventional DC / DC converters. The secondary-side high-frequency switching network (secondary-side rectifier circuit) includes but is not limited to conventional full-bridge rectifier circuits and half-bridge rectifier circuits. The auxiliary network switching network includes but is not limited to conventional full-bridge rectifier circuits and half-bridge rectifier circuits, all of which are part of this adjustable DC transformer circuit and system.
[0071] It should also be noted that when there is stray inductance at the ports where the two secondary windings of transformer 2 are located, the current is significantly distorted before setting the port impedance compensation. The experimental waveform is as follows: Figure 6 As shown in the figure, the io resonant current and ira resonant current are respectively shown. After configuring some port impedance compensation, it can be observed that the ira current distortion is significantly improved, as shown in the figure. Figure 7 shown.
[0072] The present invention further provides a corresponding embodiment of a DC conversion system, comprising: a power supply, a load, and the DC conversion circuit as described above, wherein the DC conversion circuit is connected to the power supply and the load respectively.
[0073] The DC conversion system provided in this embodiment corresponds to the above-mentioned DC conversion circuit, and therefore has the same beneficial effects as the above-mentioned DC conversion circuit. Therefore, for the embodiments of the DC conversion system part, please refer to the description of the embodiments of the DC conversion circuit part, which will not be repeated here.
[0074] It should be noted that, in this specification, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.
[0075] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A DC voltage conversion circuit comprising an inverter circuit and a transformer connected to an output end of the inverter circuit, characterized in that: Also includes: A first rectifier circuit, a second rectifier circuit, a first compensation capacitor, a second compensation capacitor, a third compensation capacitor, a first DCDC module, a second DCDC module, a third DCDC module and a controller; The first DCDC module is connected in series in a loop of the inverter circuit, the primary winding of the transformer, the first secondary winding of the transformer, and the first rectifier circuit; The second DCDC module is connected in series in a loop of the inverter circuit, the primary winding of the transformer, the second secondary winding of the transformer, and the second rectifier circuit; The third DCDC module is connected in series in a loop of the third compensation capacitor, the first secondary winding of the transformer, the first rectifier circuit, the second secondary winding of the transformer, and the second rectifier circuit; The first compensation capacitor is connected in series in a loop of the inverter circuit, the primary winding of the transformer, the first secondary winding of the transformer, and the first rectifier circuit; The second compensation capacitor is connected in series in a loop of the inverter circuit, the primary winding of the transformer, the second secondary winding of the transformer, and the second rectifier circuit; The third compensation capacitor is connected in series in a loop of the first secondary winding of the transformer, the first rectifier circuit, the second secondary winding of the transformer, and the second rectifier circuit; The controller is configured to selectively control the first DCDC module, the second DCDC module, or the third DCDC module to be put into operation, and selectively control the first compensation capacitor, the second compensation capacitor, or the third compensation capacitor to be put into operation.
2. The DC transformer circuit according to claim 1, wherein: The capacitance of the first compensation capacitor, the first leakage inductance of the first secondary winding of the transformer, and the resonance period of the primary winding of the transformer satisfy a first preset magnitude relationship.
3. The DC transformer circuit according to claim 1, wherein: The capacitance of the second compensation capacitor, the second leakage inductance of the second secondary winding of the transformer, and the resonance period of the primary winding of the transformer satisfy a second preset size relationship.
4. The DC transformer circuit according to claim 1, wherein: The capacitance of the third compensation capacitor, the first leakage inductance of the first secondary winding of the transformer, and the resonant period of the second secondary winding of the transformer satisfy a third preset size relationship.
5. The DC transformer circuit according to claim 1, wherein: Also includes: A first protection device, wherein the first protection device is connected in series in a loop of the first DCDC module, the inverter circuit, the primary winding of the transformer, the first compensation capacitor, the first secondary winding of the transformer, and the first rectifier circuit, and is configured to disconnect when an overvoltage and / or overcurrent condition occurs in the loop where the first protection device is located.
6. The DC transformer circuit according to claim 1, wherein: Also includes: A second protection device, wherein the second protection device is connected in series in the loop of the second DCDC module, the inverter circuit, the primary winding of the transformer, the second compensation capacitor, the second secondary winding of the transformer and the second rectifier circuit, and is used to disconnect when an overvoltage and / or overcurrent condition occurs in the loop where the second protection device is located.
7. The DC transformer circuit according to claim 1, wherein: Also includes: A third protection device, wherein the third protection device is connected in series in the loop of the third DCDC module, the third compensation capacitor, the first secondary winding of the transformer, the first rectifier circuit, the second secondary winding of the transformer and the second rectifier circuit, and is used to disconnect when an overvoltage and / or overcurrent condition occurs in the loop where the third protection device is located.
8. The DC transformer circuit according to any one of claims 1 to 7, wherein: The controller is further configured to: After controlling the first DCDC module to be put into operation, the duty cycle of the switch tube in the first DCDC module is selected to be adjusted; after controlling the second DCDC module to be put into operation, the duty cycle of the switch tube in the second DCDC module is selected to be adjusted; after controlling the third DCDC module to be put into operation, the duty cycle of the switch tube in the third DCDC module is selected to be adjusted.
9. A DC transformer system, characterized in that: include: A power supply, a load, and a DC transformer circuit according to any one of claims 1 to 8, wherein the DC transformer circuit is connected to the power supply and the load respectively.