Control method of bidirectional converter, controller and converter

Abstract

The invention provides a control method and device of a bidirectional converter, a controller and a storage medium. The method is applied to a bidirectional DC / DC converter, and the bidirectional DC / DC converter comprises a primary side current transformation module and a secondary side current transformation module. The primary side converter module is a full-bridge converter module; the secondary side converter module comprises a first group of switches and a second group of switches on different bridge arms. The method comprises the following steps: when the DC / DC converter is in a forward working mode or a reverse working mode, controlling a switching tube of an upper bridge arm and a switching tube of a lower bridge arm in a primary side converter module to complementarily work, and determining the working modes of a first group of switches and a second group of switches according to the switching states of the diagonal switching tubes in the primary side converter module, and the first group of switches and the second group of switches are controlled to complementarily work according to the working mode. The working reliability of the bidirectional converter can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of converters, and in particular to a control method, a controller and a converter of a bidirectional converter. Background Art

[0002] With the continuous development of new energy, bidirectional converters, as energy exchangers, play an important role. Bidirectional DC / DC converters, with their low power consumption and high efficiency, have a wide range of applications.

[0003] In existing technologies, bidirectional DC / DC converters typically require shutting down the converter, switching the power generation mode, and then restarting the converter whenever the energy flow direction changes. For example, to switch from forward to reverse operation, the converter must first be shut down, then switch from forward PWM (Pulse Width Modulation) to reverse PWM. The reverse PWM is then used to control the converter, enabling reverse operation.

[0004] However, the existing technology requires restarting and switching the wave generation mode when the converter switches the working mode, which is cumbersome to control and prone to errors. Summary of the Invention

[0005] The embodiments of the present invention provide a control method, a controller and a converter for a bidirectional converter to solve the problem in the prior art that when the converter switches its working mode, it is necessary to restart the switching of the wave generation mode, which is cumbersome and error-prone.

[0006] In a first aspect, the present invention provides a control method for a bidirectional converter, which is applied to a bidirectional DC / DC converter, wherein the bidirectional DC / DC converter includes a primary-side converter module and a secondary-side converter module; the primary-side converter module is a full-bridge converter module; the secondary-side converter module includes a first group of switches and a second group of switches in different bridge arms; the method includes:

[0007] When the DC / DC converter is in a forward working mode or a reverse working mode: the switch tubes of the upper bridge arm and the switch tubes of the lower bridge arm in the primary side conversion module are controlled to work complementary to each other; and a logical operation is performed according to the switching states of the diagonal switch tubes in the primary side conversion module to determine the working modes of the first group of switches and the second group of switches, wherein the logical operation includes one of an OR operation, a NOR operation, a NAND operation, and an AND operation, and the switch state includes an on state or an off state.

[0008] In one possible implementation, the upper bridge arm of the primary-side converter module includes a first switching tube and a second switching tube, and the lower bridge arm of the primary-side converter module includes a third switching tube and a fourth switching tube; the first switching tube and the second switching tube are both connected to the primary positive electrode of the bidirectional DC / DC converter, and the third switching tube and the fourth switching tube are both connected to the primary negative electrode of the bidirectional DC / DC converter; the first switching tube and the fourth switching tube are diagonal switching tubes, and the second switching tube and the third switching tube are diagonal switching tubes;

[0009] Controlling the complementary operation of the upper and lower bridge arm switches in the primary converter module includes:

[0010] The first switch tube and the third switch tube are controlled to work in a complementary manner, and the second switch tube and the fourth switch tube are controlled to work in a complementary manner.

[0011] In a possible implementation, controlling the first switch tube and the third switch tube to operate in a complementary manner, and controlling the second switch tube and the fourth switch tube to operate in a complementary manner, includes:

[0012] When the first switch tube is controlled to be in the off state and the third switch tube is controlled to be in the on state, the second switch tube is controlled to be in the on state and the fourth switch tube is controlled to be in the off state;

[0013] When the first switch tube is controlled to be in the on state and the third switch tube is controlled to be in the off state, the second switch tube is controlled to be in the off state and the fourth switch tube is controlled to be in the on state.

[0014] In a possible implementation, the transformer module in the bidirectional DC / DC converter is a first transformer; the first switch group includes a fifth switch tube, and the second switch group includes a sixth switch tube;

[0015] A first transformer, having a primary side connected to the primary converter module, a secondary side first end connected to the secondary negative electrode of the DC / DC converter via five switching tubes, a common end connected to the secondary positive electrode of the DC / DC converter, and a secondary side second end connected to the secondary negative electrode of the DC / DC converter via a sixth switching tube;

[0016] The operating modes of the first and second groups of switches are determined based on the switching states of the diagonal switching tubes in the primary-side conversion module through logical operations, including: performing a logical operation on the switching state of the second switching tube and the switching state of the third switching tube, and using the obtained result as the operating mode of the fifth switching tube; performing a logical operation on the switching state of the first switching tube and the switching state of the fourth switching tube, and using the obtained result as the operating mode of the sixth switching tube, wherein the logical operation includes one of an OR operation, a NAND operation, and an AND operation.

[0017] In one possible implementation, the transformer module in the bidirectional DC / DC converter is a second transformer; the first group of switching tubes includes a seventh switching tube and an eighth switching tube, and the second group of switching tubes includes a ninth switching tube and a tenth switching tube; the seventh switching tube and the eighth switching tube constitute a left bridge arm of the secondary side, and the ninth switching tube and the tenth switching tube constitute a right bridge arm of the secondary side;

[0018] a second transformer, wherein the primary side is connected to the primary side converter module, the first end of the secondary side is connected to the midpoint of the right bridge arm of the secondary side, and the second end of the secondary side is connected to the midpoint of the left bridge arm of the secondary side; the seventh switching tube and the ninth switching tube are both connected to the positive output electrode of the secondary side converter module, and the eighth switching tube and the tenth switching tube are both connected to the negative output electrode of the secondary side converter module;

[0019] The operating modes of the first and second groups of switches are determined based on logical operations on the switching states of diagonal switching tubes in the primary-side converter module, including: performing a logical operation on the switching state of the second switching tube and the switching state of the third switching tube, and using the obtained result as the operating mode of the seventh switching tube; performing a logical operation on the switching state of the first switching tube and the switching state of the fourth switching tube, and using the obtained result as the operating mode of the eighth switching tube, wherein the logical operation includes one of a NOT AND operation and a NOT OR operation.

[0020] When the logic operation is a NOT operation or a NOR operation, the working mode of the ninth switch tube is the same as the working mode of the eighth switch tube, and the working mode of the tenth switch tube is the same as the working mode of the seventh switch tube.

[0021] In one possible implementation, a bidirectional DC / DC converter includes a resonant inductor, a first transformer, a filter inductor, a secondary bus capacitor, and a controller; a primary-side power conversion module includes a first switching tube, a second switching tube, a third switching tube, and a fourth switching tube; and a secondary-side power conversion module includes a fifth switching tube and a sixth switching tube. The first switching tube, the second switching tube, the third switching tube, the fourth switching tube, the fifth switching tube, and the sixth switching tube are all controlled by the controller.

[0022] The first switching tube has a drain connected to the drain of the second switching tube and the primary positive electrode of the DC / DC converter, and a source connected to the drain of the third switching tube and the second end of the primary side of the first transformer. The second switching tube has a source connected to the drain of the third switching tube and the first end of the resonant inductor. The third switching tube has a source connected to the source of the fourth switching tube, the primary negative electrode of the DC / DC converter, and the first ground.

[0023] A first transformer, having a secondary side first end connected to the drain of the fifth switching tube, a secondary side second end connected to the drain of the sixth switching tube, and a common end connected to the first end of the filter inductor;

[0024] A secondary bus capacitor, wherein a first end is respectively connected to the second end of the filter inductor and the secondary positive electrode of the DC / DC converter, and a second end is respectively connected to the source electrode of the fifth switching tube, the source electrode of the sixth switching tube, a second ground terminal, and the secondary positive electrode of the DC / DC converter; wherein the first ground terminal and the second ground terminal are different.

[0025] In one possible implementation, a bidirectional DC / DC converter includes a resonant inductor, a second transformer, a filter inductor, a secondary bus capacitor, and a controller; a primary-side current conversion module includes a first switching tube, a second switching tube, a third switching tube, and a fourth switching tube; and a secondary-side current conversion module includes a seventh switching tube, an eighth switching tube, a ninth switching tube, and a tenth switching tube, wherein the first switching tube, the second switching tube, the third switching tube, the fourth switching tube, the seventh switching tube, the eighth switching tube, the ninth switching tube, and the tenth switching tube are all controlled by the controller; a drain of the first switching tube is respectively connected to a drain of the second switching tube and a primary positive electrode of the DC / DC converter, and a source is respectively connected to a drain of the third switching tube and a primary second end of the second transformer; a source of the second switching tube is respectively connected to a drain of the third switching tube and a first end of the resonant inductor; and a source of the third switching tube is respectively connected to a source of the fourth switching tube, a primary negative electrode of the DC / DC converter, and a first ground end;

[0026] a second transformer, wherein a first end of a secondary side is respectively connected to the source of the ninth switching tube and the drain of the tenth switching tube, and a second end of a secondary side is respectively connected to the source of the seventh switching tube and the drain of the eighth switching tube;

[0027] The seventh switch tube has a drain connected to the drain of the ninth switch tube and the first end of the filter inductor respectively;

[0028] The eighth switching tube has a source connected to the source of the tenth switching tube, the second end of the secondary bus capacitor, the secondary negative electrode of the DC / DC converter, and the third ground terminal respectively; the first end of the secondary bus capacitor is connected to the second end of the filter inductor and the secondary positive electrode of the DC / DC converter; wherein the first ground terminal and the third ground terminal are different.

[0029] In a second aspect, the present invention provides a controller comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and when the processor executes the computer program, it implements the steps of the control method of the bidirectional converter as described in the first aspect or any possible implementation method of the first aspect.

[0030] In a third aspect, the present invention provides a converter comprising the controller according to the third aspect and a bidirectional DC / DC converter; the bidirectional DC / DC converter is controlled by the controller.

[0031] In a fourth aspect, the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the control method of a bidirectional converter as described in the first aspect or any possible implementation of the first aspect.

[0032] The present invention provides a control method, controller, and converter for a bidirectional converter, applicable to bidirectional DC / DC converters. The method controls the complementary operation of the upper and lower bridge arm switches in a primary converter module. The operating modes of a first and second switch group are determined based on the switching states of diagonally opposite switches in the primary converter module. Logical operations include one of an OR operation, a NOR operation, a NAND operation, and an AND operation. Both forward and reverse operation are controlled using a single wave generation method, eliminating the need to restart the converter's wave generation method. This reduces the probability of converter switching errors, simplifies control, and improves converter reliability and efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, 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 only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 This is an application scenario diagram of a full-bridge DC / DC converter provided by an embodiment of the present invention;

[0035] Figure 2 1 is a schematic diagram of a circuit structure of a bidirectional DC / DC converter provided by an embodiment of the present invention;

[0036] Figure 3 1 is a schematic diagram of the circuit structure of another bidirectional DC / DC converter provided by an embodiment of the present invention;

[0037] Figure 4 1 is a schematic diagram of a circuit structure of another bidirectional DC / DC converter provided by an embodiment of the present invention;

[0038] Figure 5 is a schematic diagram of a controller provided by an embodiment of the present invention;

[0039] Figure 6 This is a control waveform diagram of a bidirectional DC / DC converter provided by an embodiment of the present invention;

[0040] 7A to 7C The control waveform diagram of a bidirectional DC / DC converter in a forward working mode and the measured waveform diagrams of various parts according to an embodiment of the present invention;

[0041] Figures 8A to 8C The control waveform diagram of a bidirectional DC / DC converter in a reverse working mode and the measured waveform diagrams of various parts according to an embodiment of the present invention;

[0042] Figures 9A to 9C The control waveform diagram of another bidirectional DC / DC converter in the reverse working mode and the measured waveform diagrams of each part according to an embodiment of the present invention;

[0043] FIG. 10A to FIG. 10B Two or non-waveform diagrams provided for embodiments of the present invention;

[0044] Figure 11 Another waveform diagram provided by an embodiment of the present invention;

[0045] Figure 12A Two waveform diagrams provided for embodiments of the present invention;

[0046] Figure 13 Another waveform diagram provided by an embodiment of the present invention;. DETAILED DESCRIPTION

[0047] In the following description, specific details such as particular system structures and techniques are provided for purposes of illustration, not limitation, to facilitate a thorough understanding of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

[0048] In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below with reference to the accompanying drawings.

[0049] See 1, which shows an application scenario diagram of a bidirectional DC / DC converter provided by an embodiment of the present invention. Figure 1 As shown, the bidirectional DC / DC converter 10 is generally a bidirectional isolation converter that can be used in photovoltaic systems to provide both isolation and voltage conversion. For example, when the photovoltaic energy is sufficient (i.e., the bus voltage is high), the battery is charged, and at this time, the bidirectional DC / DC converter 10 is in forward mode. When the photovoltaic energy is insufficient (i.e., the bus voltage is low), the battery supplies power to the bus, and at this time, the bidirectional DC / DC converter 10 is in reverse mode. The bidirectional DC / DC converter 10 can be considered to be equivalent to an isolation switch, and the operating mode of the DC / DC converter 10 is controlled by an external controller based on actual conditions.

[0050] Optionally, in general, a bidirectional DC / DC converter includes a primary side conversion module, a converter module and a secondary side conversion module. The primary side conversion module is generally a full-bridge conversion module, the converter module is used for isolated conversion, and the secondary side conversion module can be a full-bridge conversion module or a half-bridge conversion module.

[0051] The following describes the different situations of the secondary side converter module: Figure 2 , which shows a schematic diagram of the circuit structure of a bidirectional DC / DC converter provided by an embodiment of the present invention. Figure 2 As shown, the primary side current conversion module of the circuit is a full-bridge current conversion module, and the secondary side current conversion module is a half-bridge current conversion module.

[0052] Specifically, Figure 2 The bidirectional DC / DC converter shown includes a resonant inductor Lr, a first transformer TX1, a filter inductor Lo, a secondary bus capacitor Co, and a controller. The primary-side current conversion module includes a first switch tube Q1, a second switch tube Q2, a third switch tube Q3, and a fourth switch tube Q4. The secondary-side current conversion module includes a fifth switch tube Q5 and a sixth switch tube Q6. The first switch tube Q1, the second switch tube Q2, the third switch tube Q3, the fourth switch tube Q4, the fifth switch tube Q5, and the sixth switch tube Q6 are all controlled by the controller.

[0053] The drain of the first switching transistor Q1 is connected to the drain of the second switching transistor Q2 and the primary positive electrode P+ of the DC / DC converter, and the source is connected to the drain of the third switching transistor Q3 and the second end of the primary side of the first transformer TX1. The source of the second switching transistor Q2 is connected to the drain of the third switching transistor Q3 and the first end of the resonant inductor Lr. The source of the third switching transistor Q3 is connected to the source of the third switching transistor Q3, the primary negative electrode P- of the DC / DC converter, and the first ground G1. The first transformer TX1 has a secondary first end connected to the drain of the fifth switching transistor Q5, a secondary second end connected to the drain of the sixth switching transistor Q6, and a common end connected to the first end of the filter inductor Lo.

[0054] A secondary bus capacitor Co has a first end connected to the second end of the filter inductor Lo and the secondary positive electrode S+ of the DC / DC converter, respectively, and a second end connected to the source of the fifth switching transistor Q5, the source of the sixth switching transistor Q6, a second ground terminal G2, and the secondary positive electrode S+ of the DC / DC converter, respectively; wherein the first ground terminal G1 and the second ground terminal G2 are different.

[0055] Optionally, the first transformer may be a three-winding transformer.

[0056] Optional, see Figure 3 , which shows a circuit structure diagram of another bidirectional DC / DC converter according to an embodiment of the present invention. Figure 3As shown, the bidirectional DC / DC converter may further include an isolation capacitor Cb and a primary bus capacitor Ci. The isolation capacitor Cb is connected between the resonant inductor Lr and the midpoint of the left bridge arm of the primary converter module, and the primary bus capacitor Ci is connected between the primary positive electrode P+ and the primary negative electrode P-. Point A represents the midpoint of the left bridge arm of the primary converter module, point B represents the midpoint of the right bridge arm of the primary converter module, C represents the common terminal of the first transformer TX1, and D represents the secondary negative electrode, i.e., the midpoint of the bridge arm of the fifth and sixth switching tubes.

[0057] See also Figure 4 , which shows a circuit structure diagram of another bidirectional DC / DC converter according to an embodiment of the present invention. Figure 4 As shown, the primary side conversion module and the secondary side conversion module of the circuit are both full-bridge conversion modules.

[0058] Specifically, Figure 4 The primary side conversion module of the bidirectional DC / DC converter shown in FIG Figure 2 and Figure 3 Similarly, the primary side converter module includes a first switch tube Q1, a second switch tube Q2, a third switch tube Q3 and a fourth switch tube Q4, and also includes a resonant inductor Lr, a filter inductor Lo, a secondary side bus capacitor Co and a controller;

[0059] Figure 4 and Figure 2 The difference is that Figure 4 The transformer module is a second transformer, the secondary side current conversion module includes a seventh switch tube Q7, an eighth switch tube Q8, a ninth switch tube Q9 and a tenth switch tube Q10, and the first switch tube Q1, the second switch tube Q2, the third switch tube Q3, the fourth switch tube Q4, the seventh switch tube Q7, the eighth switch tube Q8, the ninth switch tube Q9 and the tenth switch tube Q10 are all controlled by a controller;

[0060] The drain of the first switching tube Q1 is respectively connected to the drain of the second switching tube Q2 and the primary positive electrode P+ of the DC / DC converter, and the source is respectively connected to the drain of the third switching tube Q3 and the second end of the primary side of the second transformer TX2; the source of the second switching tube Q2 is respectively connected to the drain of the third switching tube Q3 and the first end of the resonant inductor Lr; the source of the third switching tube Q3 is respectively connected to the source of the fourth switching tube Q3, the primary negative electrode P- of the DC / DC converter, and the first ground terminal G1;

[0061] The second transformer TX2 has a secondary first end connected to the source of the ninth switching tube Q9 and the drain of the tenth switching tube Q10, respectively, and a secondary second end connected to the source of the seventh switching tube Q7 and the drain of the eighth switching tube Q8, respectively. The drain of the seventh switching tube Q7 is connected to the drain of the ninth switching tube Q9 and the first end of the filter inductor Lo, respectively. The source of the eighth switching tube Q8 is connected to the source of the tenth switching tube Q10, the second end of the secondary bus capacitor Co, the secondary negative electrode S- of the DC / DC converter, and the third ground G3, respectively. The first end of the secondary bus capacitor Co is connected to the second end of the filter inductor Lo and the secondary positive electrode S+ of the DC / DC converter. The first ground G1 and the third ground G3 are different.

[0062] Optionally, the second transformer may be a two-winding transformer.

[0063] like Figure 2 、 Figure 3 、 Figure 4 As shown, the secondary side conversion module of the bidirectional DC / DC converter can be a full-bridge conversion module or a half-bridge conversion module. In the embodiment of the present invention, the secondary side conversion module can be represented by a first group of switches and a second group of switches.

[0064] Optionally, when the secondary side conversion module is a half-bridge conversion module, the first group of switches may include the fifth switch Q5, and the second group of switches may include Q6; when the secondary side conversion module is a full-bridge conversion module, the first group of switches may include Q7 and Q8, and the second group of switches may include Q9 and Q10.

[0065] In addition, Q1 and Q4 are diagonal switches of the primary converter module, while Q2 and Q3 are diagonal switches of the primary converter module. Q1 and Q2 together form the upper arm of the primary converter module, while Q3 and Q4 together form the lower arm of the primary converter module.

[0066] Existing bidirectional DC / DC converters typically require shutdown to switch power generation modes when the converter's energy flow changes, making control cumbersome and error-prone. To address these issues, embodiments of the present invention provide a control method for a bidirectional converter. The control method of embodiments of the present invention is described below.

[0067] A bidirectional DC / DC converter is provided, wherein the bidirectional DC / DC converter includes a primary-side converter module and a secondary-side converter module; the primary-side converter module is a full-bridge converter module; the secondary-side converter module includes a first group of switches and a second group of switches in different bridge arms; and a control method includes:

[0068] When the DC / DC converter is in forward mode or reverse mode:

[0069] S101, controlling the switch tubes of the upper bridge arm and the switch tubes of the lower bridge arm in the primary side converter module to work complementary;

[0070] S102, performing a logical operation on the switch states of the diagonal switch tubes in the primary side converter module to determine the working modes of the first and second groups of switches; wherein the logical operation includes one of an OR operation, a NOR operation, a NAND operation, and an AND operation, and the switch state includes an on state or an off state.

[0071] Optionally, the above control method can be applied to Figure 1 、 Figure 2 、 Figure 3 or Figure 4 The bidirectional DC / DC converter shown in Figure 1. Complementary operation means that only one switch is in the on state at the same time, and the other switch is in the off state.

[0072] Controlling the complementary operation of the upper arm switch tube and the lower arm switch tube in the primary converter module refers to controlling the complementary operation of the upper arm switch tube in the primary rectifier module and the lower arm switch tube at the corresponding position in the primary rectifier module.

[0073] Specifically, such as Figure 2 、 Figure 3 or Figure 4 As shown, the primary-side converter module may include a first switch tube Q1, a second switch tube Q2, a third switch tube Q3, and a fourth switch tube Q4. Controlling the complementary operation of the switches of the upper bridge arm and the lower bridge arm in the primary-side converter module may include controlling the complementary operation of the first switch tube Q1 and the third switch tube Q3, and controlling the complementary operation of the second switch tube Q2 and the fourth switch tube Q4.

[0074] Furthermore, due to the delay in the switching process of the switching tubes, a dead time setting is incorporated into the actual design to ensure that the switches in the same bridge arm (e.g., the left bridge arm or the right bridge arm) of the primary rectifier module are not turned on simultaneously. In the embodiment of the present invention, the complementary operation may include a dead time, but the dead time is not the focus of the embodiment of the present invention and will not be discussed in detail here. The embodiment of the present invention only considers the operating state of each switch tube when the primary or secondary converter module is turned on.

[0075] The embodiment of the present invention adopts a control method to achieve a bidirectional DC / DC converter without restarting the converter's wave generation mode, thereby reducing the converter's switching error probability, simplifying the control, and improving the converter's operating reliability and efficiency.

[0076] In the embodiments of the present invention, see Figure 2 、 Figure 3 or Figure 4The step of “performing a logical operation to determine the operating modes of the first and second groups of switches according to the switch states of the diagonal switch tubes in the primary converter module” in S101 may include:

[0077] The operating mode of the first set of switches is determined according to Q1 and Q4, and the operating mode of the second set of switches is determined according to Q2 and Q3; or, the operating mode of the second set of switches is determined according to Q1 and Q4, and the operating mode of the first set of switches is determined according to Q2 and Q3.

[0078] Optional, see Figure 2 or Figure 3 The secondary side converter module is a half-bridge converter module. The operating modes of the first and second groups of switches are determined by performing a logical operation based on the switching states of the diagonal switches in the primary side converter module. Specifically, when the logical operation is an OR operation, the operation modes include: performing an OR operation on the switching states of the second switch tube Q2 and the third switch tube Q3, and using the result as the operating mode of the fifth switch tube Q5; performing an OR operation on the switching states of the first switch tube Q1 and the fourth switch tube Q4, and using the result as the operating mode of the sixth switch tube Q6. Figure 11 The shaded area of ​​the squares corresponding to Q5 and Q6 (i.e. Figure 13 ). Figure 11 The shaded part of the square is the conduction section where the corresponding switch tube can work, but the high-level part shown in the figure is actually effective, that is, the switch tubes in the shaded part of the square can be set to a high level, but the high-level part shown in the figure is the optimal implementation scheme.

[0079] When the logical operation is an AND operation, it includes: performing an AND-NOT operation on the switching state of the second switch tube Q2 and the switching state of the third switch tube Q3, performing a NOT operation on the obtained result, and using the NOT operation result as the operating mode of the fifth switch tube Q5; performing an AND-NOT operation on the switching state of the first switch tube Q1 and the switching state of the fourth switch tube Q4, performing a NOT operation on the obtained result, and using the NOT operation result as the operating mode of the sixth switch tube Q6. For details, please refer to Figure 11 The high level portion corresponding to Q5 and Q6 in the figure. It should be noted that the result of performing the AND NOT operation followed by the NOT operation satisfies the "negative times two equals a positive" principle. Therefore, the AND NOT NOT operation is consistent with the AND operation. Similarly, the OR NOT NOT operation is the same as the OR operation.

[0080] When the logical operation is a NAND operation, it includes: performing a NAND operation on the switching state of the second switch tube Q2 and the switching state of the third switch tube Q3, and using the obtained result as the working mode of the fifth switch tube Q5; performing a NAND operation on the switching state of the first switch tube Q1 and the switching state of the fourth switch tube Q4, and using the obtained result as the working mode of the sixth switch tube Q6. Figure 6 shown.

[0081] The implementation of the present invention can realize the non-restart chopped wave operation of the bidirectional DC / DC converter in the forward and reverse directions, and provides phase OR operation, AND operation and NAND operation, providing a total of three logic operations. It is suitable for bidirectional DC / DC converters, can ensure soft turning on of the primary side and hard turning on of the secondary side, and improve the working efficiency and working reliability of the converter.

[0082] Optionally, the primary rectifier module uses a 50% duty cycle phase-shifted generator. The phase shift angle is denoted as the primary phase-shift angle, which is used to control the output of the bidirectional DC / DC converter. Q1 and Q3 form a complementary generator set, while Q2 and Q4 form a complementary generator set. The primary rectifier module uses the same generator method in both forward and reverse modes. The secondary rectifier module uses a generator with a duty cycle greater than 50%.

[0083] For example, see Figure 6 , which shows a control waveform diagram of a bidirectional DC / DC converter according to an embodiment of the present invention. Figure 6 As shown, the waveforms of Q1 and Q3 are complementary, the waveforms of Q2 and Q4 are complementary, the working mode of Q6 is the waveforms AND NOT operation of Q1 and Q4, and the working mode of Q5 is the waveforms AND NOT operation of Q2 and Q3.

[0084] The following are waveform diagrams of the converter according to the embodiment of the present invention operating in different operating modes: 50% duty cycle phase-shifted wave generation on the primary side indicates soft switching; greater than 50% duty cycle on the secondary side indicates hard switching. Secondary-side wave generation can also be used when the secondary side is a full-bridge, indicating hard switching.

[0085] The first type: the primary side is the input voltage source, the secondary side is the output resistance (or current source) load, and it is in the forward working mode. 7A to 7C , which shows a control waveform diagram of a bidirectional DC / DC converter in a forward working mode according to an embodiment of the present invention and a measured waveform diagram of each part. Figure 7A The control waveforms of the four switching tubes in the primary side converter module, the actual current waveforms of the four switching tubes, and the actual voltage waveforms of the four switching tubes; Figure 7B The control waveforms of the two switching tubes in the secondary side converter module, the actual current waveforms of the two switching tubes, and the actual voltage waveforms of the two switching tubes; Figure 7C Figure 2 is the voltage and current waveform at other locations in the converter.

[0086] For example, Figure 7A In FIG, IQ1 is the current waveform of the first switch tube, Q1 is the control waveform of the first switch tube, Vds1 is the voltage waveform of the first switch tube, and the same applies to other parameters. Figure 7BIn FIG, IQ5 is the current waveform of the fifth switch tube, Q5 is the control waveform of the fifth switch tube, Vds5 is the voltage waveform of the fifth switch tube, and the same applies to other parameters. Figure 7C In the figure, ILf is the current waveform of the filter inductor, ILr is the current waveform of the resonant inductor, VAB is the voltage waveform between points A and B, VCD is the voltage waveform between points C and D, VP is the voltage waveform of the primary side, and VS is the voltage waveform of the secondary side.

[0087] The second type: the primary side is the output resistance load, the secondary side is the input voltage source, and it is in reverse working mode. Figures 8A to 8C , which shows a control waveform diagram of a bidirectional DC / DC converter in reverse working mode and the measured waveform diagrams of each part according to an embodiment of the present invention. Figure 8A The control waveforms of the four switching tubes in the primary side converter module, the actual current waveforms of the four switching tubes, and the actual voltage waveforms of the four switching tubes; Figure 8B The control waveforms of the two switching tubes in the secondary side converter module, the actual current waveforms of the two switching tubes, and the actual voltage waveforms of the two switching tubes; Figure 8C Figure 2 is the voltage and current waveform at other locations in the converter.

[0088] The third type: the primary side is the output voltage source load, the secondary side is the input current source, and it is in reverse working mode. Figures 9A to 9C , which shows the control waveform diagram of another bidirectional DC / DC converter in the reverse working mode according to an embodiment of the present invention and the measured waveform diagrams of each part. Figure 9A The control waveforms of the four switching tubes in the primary side converter module, the actual current waveforms of the four switching tubes, and the actual voltage waveforms of the four switching tubes; Figure 9B The control waveforms of the two switching tubes in the secondary side converter module, the actual current waveforms of the two switching tubes, and the actual voltage waveforms of the two switching tubes; Figure 9C Figure 2 is the voltage and current waveform at other locations in the converter.

[0089] Depend on 7A to 7C 、 Figures 8A to 8C and Figures 9A to 9C It can be seen that the implementation of the present invention can realize the non-restart chopped wave operation of the bidirectional DC / DC converter in the forward and reverse directions, while ensuring the soft turning on of the primary side and the hard turning on of the secondary side, thereby improving the working efficiency and working reliability of the converter.

[0090] In some embodiments of the present invention, see Figure 4 The secondary side converter module is a full-bridge converter module. The operating modes of the first and second groups of switches are determined by performing logical operations based on the switching states of the diagonal switches in the primary side converter module, including:

[0091] The first method is to perform an OR operation on the switching state of the second switch tube Q2 and the switching state of the third switch tube Q3, and use the obtained result as the operating mode of the seventh switch tube Q7; perform an OR operation on the switching state of the first switch tube Q1 and the switching state of the fourth switch tube Q4, and use the obtained result as the operating mode of the eighth switch tube Q8. Among them, the operating mode of the ninth switch tube Q9 is the same as the operating mode of the eighth switch tube Q8, and the operating mode of the tenth switch tube Q10 is the same as the operating mode of the seventh switch tube Q7. For details, see Figure 10A and Figure 10B The high level part of Q7-Q10. Figure 10A and Figure 10B The shaded areas in the figure represent the conduction range in which the corresponding switches can operate. However, the actual function is in the high-level portion shown in the figure. That is, the switches in the shaded areas can all be set to a high level. However, the high-level portion shown in the figure is the optimal embodiment. The black area represents the conduction time of the primary converter module of the bidirectional DC / DC converter.

[0092] The second method is to perform a NAND operation on the switching state of the second switch tube Q2 and the switching state of the third switch tube Q3, and use the result as the operating mode of the seventh switch tube Q7; perform a NAND operation on the switching state of the first switch tube Q1 and the switching state of the fourth switch tube Q4, and use the result as the operating mode of the eighth switch tube Q8. Among them, the operating mode of the ninth switch tube Q9 is the same as the operating mode of the eighth switch tube Q8, and the operating mode of the tenth switch tube Q10 is the same as the operating mode of the seventh switch tube Q7. For details, see Figure 10A The shaded area of ​​the grid Q7-Q10, that is, Figure 12A It should be understood that the order of execution of the steps in the above embodiments does not necessarily imply a specific order of execution. The order of execution of each process should be determined by its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0093] Figure 5 Schematic diagram of a controller provided by an embodiment of the present invention. Figure 5 As shown, the controller 30 of this embodiment includes: a processor 300, a memory 301, and a computer program 302 stored in the memory 301 and executable on the processor 300. When the processor 300 executes the computer program 302, the steps of the aforementioned bidirectional converter control method embodiments are implemented. Alternatively, when the processor 300 executes the computer program 302, the functions of the modules / units of the aforementioned device embodiments are implemented.

[0094] Exemplarily, the computer program 302 may be divided into one or more modules / units, one or more of which are stored in the memory 301 and executed by the processor 300 to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, and the instruction segments are used to describe the execution process of the computer program 302 in the controller 30.

[0095] The controller 30 may be a DSP chip or a single-chip microcomputer. The controller 30 may include, but is not limited to, a processor 300 and a memory 301. Those skilled in the art will appreciate that FIG10 is merely an example of the controller 30 and does not limit the controller 30. The controller 30 may include more or fewer components than shown, or may combine certain components or different components. For example, the controller may also include input and output devices, network access devices, buses, and the like.

[0096] The processor 300 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0097] The memory 301 can be an internal storage unit of the controller 30, such as a hard disk or memory of the controller 30. The memory 301 can also be an external storage device of the controller 30, such as a plug-in hard disk equipped on the controller 30, a Smart Media Card (SMC), a Secure Digital (SD) card, a flash memory card, etc. Furthermore, the memory 301 can include both the internal storage unit of the controller 30 and an external storage device. The memory 301 is used to store computer programs and other programs and data required by the controller. The memory 301 can also be used to temporarily store data that has been output or is about to be output.

[0098] An embodiment of the present invention further provides a converter, comprising the controller 30 as described above and a bidirectional DC / DC converter; the bidirectional DC / DC converter is controlled by the controller.

[0099] Alternatively, a bidirectional DC / DC converter can be used as Figure 2、 Figure 3 or Figure 4 shown.

[0100] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0101] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0102] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0103] In the embodiments provided by the present invention, it should be understood that the disclosed devices / controllers and methods can be implemented in other ways. For example, the device / controller embodiments described above are merely schematic. For example, the division of modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0104] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0105] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0106] If the integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention can implement all or part of the process of the above-mentioned embodiment method by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, it can implement the steps of the above-mentioned each bidirectional converter control method embodiment. The computer program includes computer program code, which can be in source code form, object code form, executable file, or some intermediate form. The computer-readable medium can include: any entity or device capable of carrying computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal, and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media does not include electric carrier signals and telecommunication signals.

[0107] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A control method for a bidirectional converter, characterized in that: Applicable to a bidirectional DC / DC converter, the bidirectional DC / DC converter includes a primary side current conversion module and a secondary side current conversion module; The primary side current conversion module is a full-bridge current conversion module; The secondary side current conversion module includes a first group of switches and a second group of switches in different bridge arms; the control method includes: When the DC / DC converter is in the forward working mode or the reverse working mode: Controlling the switch tubes of the upper bridge arm and the lower bridge arm in the primary side converter module to work in a complementary manner; The operating modes of the first group of switches and the second group of switches are determined by performing a logical operation based on the switching states of the diagonal switching tubes in the primary side conversion module, wherein the logical operation includes one of an OR operation, a NOR operation, a NAND operation, and an AND operation, and the switch state includes an on state or an off state.

2. The control method of the bidirectional converter according to claim 1, wherein: The upper bridge arm of the primary-side conversion module includes a first switching tube and a second switching tube, and the lower bridge arm of the primary-side conversion module includes a third switching tube and a fourth switching tube; the first switching tube and the second switching tube are both connected to the primary positive electrode of the bidirectional DC / DC converter, and the third switching tube and the fourth switching tube are both connected to the primary negative electrode of the bidirectional DC / DC converter; the first switching tube and the fourth switching tube are diagonal switching tubes, and the second switching tube and the third switching tube are diagonal switching tubes; The controlling of the switch tubes of the upper bridge arm and the lower bridge arm in the primary side converter module to operate complementary to each other includes: The first switch tube and the third switch tube are controlled to work in a complementary manner, and the second switch tube and the fourth switch tube are controlled to work in a complementary manner.

3. The control method of the bidirectional converter according to claim 2, wherein: The controlling the first switch tube and the third switch tube to work in a complementary manner, and controlling the second switch tube and the fourth switch tube to work in a complementary manner, includes: When the first switch tube is controlled to be in an off state and the third switch tube is controlled to be in an on state, the second switch tube is controlled to be in an on state and the fourth switch tube is controlled to be in an off state; When the first switch tube is controlled to be in the on state and the third switch tube is controlled to be in the off state, the second switch tube is controlled to be in the off state and the fourth switch tube is controlled to be in the on state.

4. The control method of the bidirectional converter according to claim 3, wherein: The transformer module in the bidirectional DC / DC converter is a first transformer; the first switch group includes a fifth switch tube, and the second switch group includes a sixth switch tube; The first transformer has a primary side connected to the primary side converter module, a secondary side first end connected to the secondary negative electrode of the DC / DC converter through the five switching transistors, a common end connected to the secondary positive electrode of the DC / DC converter, and a secondary side second end connected to the secondary negative electrode of the DC / DC converter through the sixth switching transistor; The determining the operating modes of the first group of switches and the second group of switches by performing a logical operation according to the switch states of the diagonal switch tubes in the primary side converter module includes: A logical operation is performed on the switching state of the second switching tube and the switching state of the third switching tube, and the obtained result is used as the operating mode of the fifth switching tube; a logical operation is performed on the switching state of the first switching tube and the switching state of the fourth switching tube, and the obtained result is used as the operating mode of the sixth switching tube, wherein the logical operation includes one of an OR operation, a NAND operation, and an AND operation.

5. The control method of the bidirectional converter according to claim 3, wherein: The transformer module in the bidirectional DC / DC converter is a second transformer; the first group of switching transistors includes a seventh switching transistor and an eighth switching transistor, and the second group of switching transistors includes a ninth switching transistor and a tenth switching transistor; the seventh switching transistor and the eighth switching transistor constitute a left bridge arm of the secondary side, and the ninth switching transistor and the tenth switching transistor constitute a right bridge arm of the secondary side; The second transformer has a primary side connected to the primary side converter module, a secondary side first end connected to the midpoint of the secondary side right bridge arm, and a secondary side second end connected to the midpoint of the secondary side left bridge arm; the seventh switch tube and the ninth switch tube are both connected to the positive output electrode of the secondary side converter module, and the eighth switch tube and the tenth switch tube are both connected to the negative output electrode of the secondary side converter module; The determining the operating modes of the first group of switches and the second group of switches by performing a logical operation according to the switch states of the diagonal switch tubes in the primary side converter module includes: A logical operation is performed on the switching state of the second switching tube and the switching state of the third switching tube, and the obtained result is used as the operating mode of the seventh switching tube; a logical operation is performed on the switching state of the first switching tube and the switching state of the fourth switching tube, and the obtained result is used as the operating mode of the eighth switching tube, where the logical operation includes one of a NOT AND operation and a NOT OR operation.

6. The control method of the bidirectional converter according to claim 5, characterized in that: When the logic operation is one of a NOT and NOT operation and a NOT OR operation, the working mode of the ninth switch tube is the same as the working mode of the eighth switch tube, and the working mode of the tenth switch tube is the same as the working mode of the seventh switch tube.

7. The control method of a bidirectional converter according to any one of claims 1 to 3, characterized in that: The bidirectional DC / DC converter includes a resonant inductor, a first transformer, a filter inductor, a secondary bus capacitor, and a controller; the primary side current conversion module includes a first switch tube, a second switch tube, a third switch tube, and a fourth switch tube; the secondary side current conversion module includes a fifth switch tube and a sixth switch tube, and the first switch tube, the second switch tube, the third switch tube, the fourth switch tube, the fifth switch tube, and the sixth switch tube are all controlled by the controller; The first switching tube has a drain connected to the drain of the second switching tube and the primary positive electrode of the DC / DC converter, and a source connected to the drain of the third switching tube and the second end of the primary side of the first transformer. The source of the second switch tube is connected to the drain of the third switch tube and the first end of the resonant inductor respectively; The source of the third switch tube is respectively connected to the source of the fourth switch tube, the primary negative electrode of the DC / DC converter and the first ground terminal; The first transformer has a first end of a secondary side connected to the drain of the fifth switch tube, a second end of a secondary side connected to the drain of the sixth switch tube, and a common end connected to the first end of the filter inductor; The secondary bus capacitor has a first end connected to the second end of the filter inductor and the secondary positive electrode of the DC / DC converter, respectively, and a second end connected to the source of the fifth switching tube, the source of the sixth switching tube, a second ground terminal, and the secondary positive electrode of the DC / DC converter, respectively; wherein the first ground terminal and the second ground terminal are different.

8. The control method of a bidirectional converter according to any one of claims 1 to 3, characterized in that: The bidirectional DC / DC converter includes a resonant inductor, a second transformer, a filter inductor, a secondary bus capacitor, and a controller; the primary side power conversion module includes a first switch tube, a second switch tube, a third switch tube, and a fourth switch tube; the secondary side power conversion module includes a seventh switch tube, an eighth switch tube, a ninth switch tube, and a tenth switch tube; the first switch tube, the second switch tube, the third switch tube, the fourth switch tube, the seventh switch tube, the eighth switch tube, the ninth switch tube, and the tenth switch tube are all controlled by the controller; The first switching tube has a drain connected to the drain of the second switching tube and the primary positive electrode of the DC / DC converter, and a source connected to the drain of the third switching tube and the second end of the primary side of the second transformer. The source of the second switch tube is connected to the drain of the third switch tube and the first end of the resonant inductor respectively; The source of the third switch tube is respectively connected to the source of the fourth switch tube, the primary negative electrode of the DC / DC converter and the first ground terminal; The second transformer has a first end of a secondary side connected to the source of the ninth switching tube and the drain of the tenth switching tube, and a second end of a secondary side connected to the source of the seventh switching tube and the drain of the eighth switching tube; The drain of the seventh switch tube is connected to the drain of the ninth switch tube and the first end of the filter inductor respectively; The source of the eighth switching tube is respectively connected to the source of the tenth switching tube, the second end of the secondary bus capacitor, the secondary negative electrode of the DC / DC converter and the third ground terminal; the first end of the secondary bus capacitor is connected to the second end of the filter inductor and the secondary positive electrode of the DC / DC converter; wherein the first ground terminal and the third ground terminal are different.

9. A controller comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, characterized in that: When the processor executes the computer program, the steps of the method for controlling the bidirectional converter according to any one of claims 1 to 8 are implemented.

10. A converter, characterized in that: The invention comprises the controller as claimed in claim 9 and a bidirectional DC / DC converter; the bidirectional DC / DC converter is controlled by the controller.

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