Bidirectional DC conversion circuit, charger and vehicle

Abstract

The invention belongs to the technical field of energy storage, and provides a bidirectional DC conversion circuit, a charger and a vehicle. The conversion circuit comprises a first bridge arm module, a second bridge arm module, an energy storage module and a control module, the first bridge arm module is respectively connected with the power supply module, the energy storage module and the control module, the second bridge arm module is respectively connected with the super capacitor module, the energy storage module and the control module, and the control module is connected with the energy storage module. The control module controls the on-off state of the first bridge arm module and the second bridge arm module according to the first voltage, the second voltage and the first current so as to control the first current and further control the electric energy storage or release of the energy storage module. The current flowing through the energy storage module is collected, and the two bridge arm modules are accurately controlled according to the current, the voltage on the power supply module and the voltage on the super-capacitor module, so that the current is effectively controlled during bidirectional conversion, and the super-capacitor module can be directly charged after being completely discharged.

Description

Technical Field

[0001] The present application belongs to the field of energy storage technology, and in particular relates to a bidirectional direct current conversion circuit, a charger and a vehicle. Background Art

[0002] Supercapacitors are rapidly being applied to automotive power, braking, steering, suspension and other system technologies due to their long service life, high power density and fast charging and discharging capabilities. Therefore, supercapacitor-based chargers are becoming one of the key technologies for automobiles.

[0003] Current chargers have bidirectional energy flow capabilities, constant current charging capabilities, and constant voltage charging capabilities. However, when the voltage of the supercapacitor is lower than the voltage of the vehicle battery, if the charger is powered on directly, a large uncontrollable surge current will be generated, which may not only damage circuit components but also cause serious impact on the system. Therefore, it is necessary to set up a pre-charging circuit and a switching circuit in the charger. Although this avoids the impact of large currents, it prevents the supercapacitor from being charged directly from a fully discharged state. Summary of the invention

[0004] The embodiments of the present application provide a bidirectional DC conversion circuit, a charger and a vehicle, which can solve the problem that the current charger cannot meet the requirement of charging a supercapacitor directly from a fully discharged state.

[0005] In a first aspect, an embodiment of the present application provides a bidirectional DC conversion circuit, including a first bridge arm module, a second bridge arm module, an energy storage module and a control module, wherein the first bridge arm module is respectively connected to a power supply module, the energy storage module and the control module, the second bridge arm module is respectively connected to a supercapacitor module, the energy storage module and the control module, and the control module is connected to the energy storage module;

[0006] The control module is used to collect a first voltage, a second voltage and a first current, and control the on-off state of the first bridge arm module and the second bridge arm module according to the first voltage, the second voltage and the first current, so as to control the first current, and further control the storage or release of electric energy of the energy storage module; wherein the first voltage is the voltage on the power module, the second voltage is the voltage on the supercapacitor module, and the first current is the current flowing through the energy storage module.

[0007] In a possible implementation of the first aspect, the control module is further configured to be connected to a vehicle controller;

[0008] The control module is also used to obtain the control instructions output by the vehicle controller, and control the on and off states of the first bridge arm module and the second bridge arm module according to the control instructions, thereby controlling the storage or release of electric energy of the energy storage module.

[0009] In a possible implementation of the first aspect, the bidirectional DC conversion circuit further includes a temperature acquisition module, and the temperature acquisition module is connected to the control module and the super capacitor module respectively;

[0010] The temperature acquisition module is used to acquire a first temperature and a second temperature, and transmit the first temperature and the second temperature to the control module; the control module is also used to control the on and off states of the first bridge arm module and the second bridge arm module according to the first temperature and the second temperature, thereby controlling the storage or release of electric energy of the energy storage module; wherein the first temperature is the temperature of the supercapacitor module, and the second temperature is the temperature of the environment in which the supercapacitor module is located.

[0011] In a possible implementation manner of the first aspect, the control module includes a control unit, a first drive unit, and a second drive unit, the control unit is respectively connected to the first drive unit, the second drive unit, the energy storage module, the power supply module, and the supercapacitor module, the first drive unit is connected to the first bridge arm module, and the second drive unit is connected to the second bridge arm module;

[0012] The control unit is used to collect the first voltage, the second voltage and the first current, and output a first drive signal to the first drive unit according to the first voltage, the second voltage and the first current, and output a second drive signal to the second drive unit, so that the first drive unit controls the on-off state of the first bridge arm module according to the first drive signal, and the second drive unit controls the on-off state of the second bridge arm module according to the second drive signal, so as to control the first current, and further control the storage or release of electric energy of the energy storage module.

[0013] In a possible implementation of the first aspect, the control unit includes a PWM generation subunit, a current loop subunit, a voltage loop subunit and a control subunit, the current loop subunit is respectively connected to the energy storage module, the voltage loop subunit and the PWM generation subunit, the PWM generation subunit is respectively connected to the first drive unit, the second drive unit, the voltage loop subunit and the control subunit, and the control subunit is respectively connected to the voltage loop subunit, the vehicle controller, the temperature acquisition module, the power supply module and the supercapacitor module;

[0014] The control subunit is used to output a first reference voltage and a second reference voltage, and is also used to output an energy transfer signal and a control signal according to the control instruction output by the vehicle controller, the first temperature, the second temperature output by the temperature acquisition module, and the collected first voltage and second voltage; the voltage loop subunit is used to output a first signal according to the energy transfer signal, the first reference voltage, the second reference voltage, and the collected first voltage and second voltage; the current loop subunit is used to output a second signal according to the first signal and the collected first current; the PWM generation subunit is used to output the first drive signal to the first drive unit and output the second drive signal to the second drive unit according to the triangular wave signal, the second signal, the control signal and the energy transfer signal.

[0015] In a possible implementation of the first aspect, the PWM generation subunit includes a PWM generator and a PWM controller, the PWM generator is respectively connected to the current loop subunit and the PWM controller, and the PWM controller is respectively connected to the first drive unit, the second drive unit, the control subunit, and the voltage loop subunit;

[0016] The PWM generator is used to output a PWM signal to the PWM controller according to the triangular wave signal and the second signal; the PWM controller is used to output a first drive signal to the first drive unit and a second drive signal to the second drive unit according to the energy transfer signal, the control signal and the PWM signal.

[0017] In a possible implementation of the first aspect, the voltage loop subunit includes a voltage loop selector, a first voltage loop, and a second voltage loop, the voltage loop selector is respectively connected to the first voltage loop, the second voltage loop, the current loop subunit, the PWM generation subunit, and the control subunit, the first voltage loop is respectively connected to the power supply module and the control subunit, and the second voltage loop is respectively connected to the supercapacitor module and the control subunit; the first signal includes a third signal and a fourth signal;

[0018] The first voltage loop is used to output a third signal based on the first reference voltage and the collected first voltage; the second voltage loop is used to output a fourth signal based on the second reference voltage and the collected second voltage; the voltage loop selector is used to transmit the third signal or the fourth signal to the current loop sub-unit according to the energy transfer signal.

[0019] In a possible implementation manner of the first aspect, the energy storage module includes an energy storage unit and a current acquisition unit, the energy storage unit is respectively connected to the first bridge arm module and the current acquisition unit, and the current acquisition unit is respectively connected to the second bridge arm module and the control module;

[0020] The current acquisition unit is used to acquire the first current and transmit the first current to the control module; the energy storage unit is used to store and release electric energy according to the first current.

[0021] In a second aspect, an embodiment of the present application provides a charger, comprising the bidirectional DC conversion circuit described in any one of the first aspects.

[0022] In a third aspect, an embodiment of the present application provides a vehicle, comprising the bidirectional DC conversion circuit described in any one of the first aspects.

[0023] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0024] An embodiment of the present application provides a bidirectional DC conversion circuit, including a first bridge arm module, a second bridge arm module, an energy storage module and a control module, wherein the first bridge arm module is respectively connected to the power supply module, the energy storage module and the control module, the second bridge arm module is respectively connected to the supercapacitor module, the energy storage module and the control module, and the control module is connected to the energy storage module.

[0025] The control module is used to collect the first voltage, the second voltage and the first current, and control the on / off state of the first bridge arm module and the second bridge arm module according to the first voltage, the second voltage and the first current, so as to control the first current, and then control the energy storage or release of the energy storage module, so as to realize the bidirectional buck-boost conversion between the power module and the supercapacitor module. Among them, the first voltage is the voltage on the power module, the second voltage is the voltage on the supercapacitor module, and the first current is the current flowing through the energy storage module.

[0026] The control module in the present application collects the current (i.e., the first current) flowing through the energy storage module, and according to the current and the voltage on the power module and the voltage on the supercapacitor module, accurately controls the first bridge arm module and the second bridge arm module, thereby realizing effective control of the current when performing bidirectional conversion. Since the bidirectional DC conversion circuit proposed in the present application can effectively control the current, the supercapacitor module can be directly charged after it is fully discharged, and the overall circuit architecture does not need to add a pre-charge circuit and a switching circuit, reducing the complexity and cost of the circuit design.

[0027] It can be understood that the beneficial effects of the second to third aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0029] Figure 1 It is a principle block diagram of a bidirectional DC conversion circuit provided in an embodiment of the present application;

[0030] Figure 2 is a principle block diagram of a bidirectional DC conversion circuit provided in another embodiment of the present application;

[0031] Figure 3 is a principle block diagram of a bidirectional DC conversion circuit provided in another embodiment of the present application;

[0032] Figure 4 is a principle block diagram of a bidirectional DC conversion circuit provided in another embodiment of the present application;

[0033] Figure 5 is a principle block diagram of a bidirectional DC conversion circuit provided in another embodiment of the present application;

[0034] Figure 6 is a principle block diagram of a bidirectional DC conversion circuit provided in another embodiment of the present application;

[0035] Figure 7 is a principle block diagram of a bidirectional DC conversion circuit provided in another embodiment of the present application;

[0036] Figure 8 1 is a circuit connection diagram of a bidirectional DC conversion circuit provided in an embodiment of the present application;

[0037] Fig. 9 This is a schematic diagram of a working mode 1 of a bidirectional DC conversion circuit provided by an embodiment of the present application;

[0038] Fig.10 This is a schematic diagram of a second working mode of a bidirectional DC conversion circuit provided by an embodiment of the present application;

[0039] Fig.11 This is a schematic diagram of the third working mode of the bidirectional DC conversion circuit provided by an embodiment of the present application;

[0040] Fig.12 This is a schematic diagram of working mode 4 of a bidirectional DC conversion circuit provided in one embodiment of the present application.

[0041] In the figure: 1. first bridge arm module; 2. second bridge arm module; 3. energy storage module; 30. energy storage unit; 31. current acquisition unit; 4. control module; 40. control unit; 401. PWM generation subunit; 4011. PWM generator; 4012. PWM controller; 402. current loop subunit; 403. voltage loop subunit; 4031. voltage loop selector; 4032. first voltage loop; 4033. second voltage loop; 404. control subunit; 41. first drive unit; 42. second drive unit; 5. power module; 6. supercapacitor module; 7. vehicle controller; 8. temperature acquisition module. DETAILED DESCRIPTION

[0042] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0043] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0044] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0045] As used in the specification and appended claims of this application, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce [described condition or event] is detected" or "in response to detecting [described condition or event]", depending on the context.

[0046] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0047] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0048] Supercapacitors are rapidly being applied to automotive power, braking, steering, suspension and other system technologies due to their long service life, high power density and fast charging and discharging capabilities. Since supercapacitors are essentially capacitors, their charging and discharging processes require precise management, so a special charger is needed to manage their charging and discharging processes, which makes supercapacitor-based chargers increasingly becoming one of the key technologies for automobiles.

[0049] Current chargers have bidirectional energy flow capabilities, constant current charging capabilities, and constant voltage charging capabilities. However, when the voltage of the supercapacitor is lower than the voltage of the vehicle battery, if the charger is powered on directly, a large uncontrollable surge current will be generated, which may not only damage circuit components but also cause serious impact on the system. Therefore, it is necessary to set up a pre-charging circuit and a switching circuit in the charger. Although this avoids the impact of large currents, it prevents the supercapacitor from being charged directly from a fully discharged state.

[0050] In view of the above problems, the present application provides a bidirectional DC conversion circuit. Figure 1 As shown, the bidirectional DC conversion circuit includes a first bridge arm module 1, a second bridge arm module 2, an energy storage module 3 and a control module 4. The first bridge arm module 1 is respectively connected to the power module 5, the energy storage module 3 and the control module 4, the second bridge arm module 2 is respectively connected to the super capacitor module 6, the energy storage module 3 and the control module 4, and the control module 4 is connected to the energy storage module 3. In the embodiment of the present application, the power module 5 is a vehicle-mounted battery.

[0051] Specifically, the control module 4 is used to collect the first voltage, the second voltage and the first current, and control the on / off state of the first bridge arm module 1 and the second bridge arm module 2 according to the first voltage, the second voltage and the first current, so as to control the first current, and then control the electric energy storage or release of the energy storage module 3, and realize the bidirectional buck-boost conversion between the power module 5 and the super capacitor module 6 (that is, both the forward conversion and the reverse conversion have the buck-boost capability). Among them, the first voltage is the voltage on the power module 5, the second voltage is the voltage on the super capacitor module 6, and the first current is the current flowing through the energy storage module 3.

[0052] The control module 4 in the present application collects the current (i.e., the first current) flowing through the energy storage module 3, and accurately controls the first bridge arm module 1 and the second bridge arm module 2 according to the current and the voltage on the power module 5 and the voltage on the super capacitor module 6, thereby realizing effective control of the current when performing bidirectional conversion. Since the bidirectional DC conversion circuit proposed in the present application can effectively control the current, the super capacitor module 6 can be directly charged after it is fully discharged, and the overall circuit architecture does not need to add a pre-charge circuit and a switching circuit, reducing the complexity and cost of the circuit design.

[0053] In some embodiments, although current chargers have bidirectional energy flow capabilities, they cannot meet the requirements of intelligent energy control.

[0054] like Figure 2 As shown, the control module 4 in the present application is also used to connect to the vehicle controller 7. The control module 4 is also used to obtain the control instructions output by the vehicle controller 7, and control the on-off state of the first bridge arm module 1 and the second bridge arm module 2 according to the control instructions, thereby controlling the storage or release of electric energy of the energy storage module 3, and realizing the bidirectional buck-boost conversion between the power module 5 and the super capacitor module 6.

[0055] Specifically, the control module 4 will also control the on / off state of the first bridge arm module 1 and the second bridge arm module 2 according to the control instruction output by the vehicle controller 7. In this way, the control module 4 can further accurately control the energy storage or release process of the energy storage module 3. This enables the bidirectional DC conversion circuit to better adapt to changes in the energy demand of the vehicle and meet intelligent energy control. For example, in an electric vehicle, the charge and discharge state of the supercapacitor module 6 is adjusted according to the driving mode or load demand to achieve optimal utilization of the energy of the vehicle.

[0056] It should be noted that CANFD communication is adopted between the control module 4 and the vehicle controller 7 to achieve the purpose of real-time interactive communication.

[0057] In some embodiments, in order to further meet the intelligent energy control, such as Figure 3As shown, the bidirectional DC conversion circuit provided in the embodiment of the present application also includes a temperature acquisition module 8, which is connected to the control module 4 and the super capacitor module 6 respectively. The temperature acquisition module 8 is used to collect the first temperature and the second temperature, and transmit the first temperature and the second temperature to the control module 4. The control module 4 is also used to control the on-off state of the first bridge arm module 1 and the second bridge arm module 2 according to the first temperature and the second temperature, thereby controlling the storage or release of electric energy of the energy storage module 3, and realizing the bidirectional buck-boost conversion between the power module 5 and the super capacitor module 6. Among them, the first temperature is the temperature of the super capacitor module 6, and the second temperature is the temperature of the environment in which the super capacitor module 6 is located.

[0058] Specifically, the control module 4 will also determine whether the working state of the super capacitor module 6 is safe based on the collected first temperature and second temperature. If the temperature is too high, the control module 4 can adjust the on / off state of the first bridge arm module 1 and the second bridge arm module 2, reduce or stop the energy storage and release of the energy storage module 3, thereby protecting the super capacitor module 6 from damage, and also improving the reliability and safety of the bidirectional DC conversion circuit.

[0059] It should be noted that the present application completes the relationship between the voltage on the supercapacitor module 6 and the first temperature and the second temperature through calculation, simulation, calibration and other designs, and builds this relationship into the control module 4, so that the control module 4 can intelligently adjust the conversion and transmission of energy according to the first temperature and the second temperature.

[0060] In summary, the bidirectional DC conversion circuit provided in the embodiment of the present application realizes intelligent energy control. In the application of the chassis wire-controlled actuator of the automobile, due to the large power required by the wire-controlled braking, the transient power of the existing automobile bus voltage cannot meet the transient high-power demand of the chassis wire-controlled actuator. The bidirectional DC conversion circuit provided in the embodiment of the present application uses an intelligent energy control strategy to monitor and adjust the energy flow in real time to ensure that sufficient transient power is provided to the chassis wire-controlled actuator when needed, thereby meeting its high-power demand. The present application not only solves the contradiction between the transient high-power demand of the chassis wire-controlled actuator and the insufficient transient power of the existing automobile bus voltage, but also complies with the relevant regulatory requirements of the electric brake system; at the same time, through the intelligent control of the supercapacitor module 6, the current pressure of the vehicle battery is also optimized, which is not only beneficial to the stability of the low-voltage electrical system of the whole vehicle, but also prolongs the service life of the vehicle battery.

[0061] In some embodiments, Figure 4As shown, the control module 4 includes a control unit 40, a first drive unit 41 and a second drive unit 42. The control unit 40 is respectively connected to the first drive unit 41, the second drive unit 42, the energy storage module 3, the power supply module 5 and the supercapacitor module 6. The first drive unit 41 is connected to the first bridge arm module 1, and the second drive unit 42 is connected to the second bridge arm module 2.

[0062] Specifically, the control unit 40 is used to collect the first voltage, the second voltage and the first current, and output a first drive signal to the first drive unit 41 according to the first voltage, the second voltage and the first current, and output a second drive signal to the second drive unit 42, so that the first drive unit 41 controls the on-off state of the first bridge arm module 1 according to the first drive signal, and the second drive unit 42 controls the on-off state of the second bridge arm module 2 according to the second drive signal, so as to control the first current, and then control the storage or release of electric energy of the energy storage module 3.

[0063] It should be noted that the first driving unit 41 and the second driving unit 42 can realize the driving of the first bridge arm module 1 and the second bridge arm module 2 at any duty cycle. Exemplarily, a charge pump circuit is added to the first driving unit 41 and the second driving unit 42 to realize the driving of the first bridge arm module 1 and the second bridge arm module 2 at any duty cycle, and the circuit structure of the charge pump circuit is not limited in this application.

[0064] In some embodiments, Figure 5 As shown, the control unit 40 includes a PWM generating subunit 401, a current loop subunit 402, a voltage loop subunit 403 and a control subunit 404. The current loop subunit 402 is respectively connected to the energy storage module 3, the voltage loop subunit 403 and the PWM generating subunit 401. The PWM generating subunit 401 is respectively connected to the first driving unit 41, the second driving unit 42, the voltage loop subunit 403 and the control subunit 404. The control subunit 404 is respectively connected to the voltage loop subunit 403, the vehicle controller 7, the temperature acquisition module 8, the power supply module 5 and the supercapacitor module 6.

[0065] Specifically, the control subunit 404 is used to output the first reference voltage and the second reference voltage, and is also used to output the energy transfer signal and the control signal according to the control instruction output by the vehicle controller 7, the first temperature and the second temperature output by the temperature acquisition module 8, and the collected first voltage and second voltage, wherein the energy transfer signal is used to determine the direction of energy transfer; the first reference voltage is the reference voltage when the energy is transmitted in the reverse direction, and the second reference voltage is the reference voltage when the energy is transmitted in the forward direction. The voltage loop subunit 403 is used to output the first signal to the current loop subunit 402 according to the energy transfer signal, the first reference voltage, the second reference voltage, and the collected first voltage and second voltage, wherein the first signal is a voltage control signal, which is used to monitor and adjust the voltage of the charged object to achieve closed-loop control of the voltage. The current loop subunit 402 is used to output the second signal to the PWM generation subunit 401 according to the first signal and the collected first current, wherein the second signal is a current control signal, which is used to monitor and adjust the current flowing through the energy storage module 3 to achieve closed-loop control of the current. The PWM generation subunit 401 is used to receive the triangular wave signal, and output the first drive signal to the first drive unit 41 and the second drive signal to the second drive unit 42 according to the triangular wave signal, the second signal, the control signal and the energy transfer signal.

[0066] The control unit 40 provided in the embodiment of the present application can realize intelligent energy control, monitor and adjust the current and voltage in real time during the energy conversion process to realize current closed-loop control and voltage closed-loop control.

[0067] It should be noted that the control subunit 404 also integrates the system state machine, system interface, logic unit, and over-voltage, over-current, over-temperature and other protection functions, thereby improving the stability and reliability of the system.

[0068] Exemplarily, the control subunit 404 includes a controller, and the type of the controller can be determined according to actual application requirements.

[0069] Exemplarily, the current loop subunit 402 is a PID (proportional-integral-derivative control) current loop, which is used to perform subtraction operation, gain processing and PID processing on the input signal in sequence.

[0070] In some embodiments, Figure 6 As shown, the PWM generation subunit 401 includes a PWM generator 4011 and a PWM controller 4012. The PWM generator 4011 is connected to the current loop subunit 402 and the PWM controller 4012 respectively. The PWM controller 4012 is connected to the first drive unit 41, the second drive unit 42, the control subunit 404 and the voltage loop subunit 403 respectively.

[0071] Specifically, the PWM generator 4011 is used to receive the triangular wave signal and the second signal, and output the PWM signal to the PWM controller 4012 according to the triangular wave signal and the second signal. The PWM controller 4012 is used to receive the energy transfer signal and the control signal, and output the first drive signal to the first drive unit 41 and the second drive signal to the second drive unit 42 according to the energy transfer signal, the control signal and the PWM signal.

[0072] In some embodiments, Figure 6 As shown, the voltage loop subunit 403 includes a voltage loop selector 4031, a first voltage loop 4032 and a second voltage loop 4033, the voltage loop selector 4031 is respectively connected to the first voltage loop 4032, the second voltage loop 4033, the current loop subunit 402, the PWM generation subunit 401 and the control subunit 404, the first voltage loop 4032 is respectively connected to the power module 5 and the control subunit 404, and the second voltage loop 4033 is respectively connected to the super capacitor module 6 and the control subunit 404. The first signal includes a third signal and a fourth signal.

[0073] Specifically, the first voltage loop 4032 is used to receive a first reference voltage, and output a third signal according to the first reference voltage and the collected first voltage, wherein the third signal is a voltage adjustment signal. The second voltage loop 4033 is used to receive a second reference voltage, and output a fourth signal according to the second reference voltage and the collected second voltage, wherein the fourth signal is a voltage adjustment signal. The voltage loop selector 4031 is used to receive an energy transfer signal, and transmit the third signal or the fourth signal to the current loop subunit 402 according to the energy transfer signal. The first voltage loop 4032 is used to implement voltage closed-loop control of reverse energy flow, and the second voltage loop 4033 is used to implement voltage closed-loop control of forward energy flow. The voltage loop selector 4031 is used to select the corresponding voltage loop for voltage closed-loop control according to the energy transfer signal. For example, when the energy transfer direction is forward, the voltage loop selector 4031 transmits the signal output by the second voltage loop 4033 to the current loop sub-unit 402, thereby realizing voltage closed-loop control of forward energy transmission; when the energy transfer direction is reverse, the voltage loop selector 4031 transmits the signal output by the first voltage loop 4032 to the current loop sub-unit 402, thereby realizing voltage closed-loop control of reverse energy transmission.

[0074] Exemplarily, the first voltage loop 4032 and the second voltage loop 4033 are both PID voltage loops, which are used to perform subtraction operations, gain processing, and PID processing on the input signal in sequence.

[0075] In some embodiments, Figure 7As shown, the energy storage module 3 includes an energy storage unit 30 and a current acquisition unit 31 . The energy storage unit 30 is connected to the first bridge arm module 1 and the current acquisition unit 31 , respectively. The current acquisition unit 31 is connected to the second bridge arm module 2 and the control module 4 , respectively.

[0076] Specifically, the current acquisition unit 31 is used to acquire the first current and transmit the first current to the control module 4. The energy storage unit 30 is used to store and release electric energy according to the first current. The present application realizes current closed-loop control by monitoring and adjusting the current flowing through the energy storage module 3, that is, the current is controllable.

[0077] For example, Figure 8 As shown, the first bridge arm module 1 includes an input capacitor Cin, a power tube QF1 and a power tube QF2, the first end of the input capacitor Cin is respectively connected to the power module 5, the control module 4 and the drain of the power tube QF1, the source of the power tube QF1 is respectively connected to the energy storage module 3 and the drain of the power tube QF2, the second end of the input capacitor Cin and the source of the power tube QF2 are both grounded, and the gate of the power tube QF1 and the gate of the power tube QF2 are respectively connected to the control module 4.

[0078] For example, Figure 8 As shown, the second bridge arm module 2 includes an output capacitor Co, a power tube QR1 and a power tube QR2. The first end of the output capacitor Co is respectively connected to the super capacitor module 6, the control module 4 and the drain of the power tube QR1, the source of the power tube QR1 is respectively connected to the energy storage module 3 and the drain of the power tube QR2, the source of the power tube QR2 and the second end of the output capacitor Co are both grounded, and the gate of the power tube QR1 and the gate of the power tube QR2 are respectively connected to the control module 4.

[0079] It should be noted that the power tubes in the first bridge arm module 1 and the second bridge arm module 2 can be MOSFETs or IGBTs.

[0080] Exemplarily, the energy storage module 3 includes an inductor L and a resistor R, wherein a first end of the inductor L is connected to the first bridge arm module 1, a second end of the inductor L is connected to a first end of the resistor R, and a second end of the resistor R is respectively connected to the second bridge arm module 2 and the control module 4. The inductor L constitutes the energy storage unit 30, and the resistor R constitutes the current acquisition unit 31.

[0081] It should be noted that the current acquisition unit 31 may also adopt a Hall or other electromagnetic current sensor.

[0082] In order to make the application more clear, Figure 8 Taking the circuit shown as an example, the working mode of the bidirectional DC conversion circuit provided in the embodiment of the present application is specifically described.

[0083] Working mode 1: When the energy transfer direction is forward and the voltage Vin on the power module 5 is higher than the voltage Vo on the supercapacitor module 6, the conduction state of the power tube QR1 is set to 100% duty cycle state, the conduction state of the power tube QR2 is set to 0% duty cycle state, the power tube QF1 is used as a switch tube, the power tube QF2 is used as a freewheeling tube, and through Figure 7 The current loop subunit 402 shown in the figure realizes current closed-loop control, and the second voltage loop 4033 realizes voltage closed-loop control. Fig. 9 As shown, the action sequence is to first turn on the power tube QF1, and the current flows from the input capacitor Cin through the power tube QF1, the inductor L, the power tube QR1, and then flows to the output capacitor Co, and the inductor L completes the energy storage. When the power tube QF1 is turned off, due to the freewheeling characteristics of the current of the inductor L, the power tube QF2 completes the freewheeling, thereby realizing the forward transmission of energy. During the energy transmission process, the voltage Vin on the power module 5 is first stepped down. When the voltage Vin on the power module 5 is equal to the voltage Vo on the super capacitor module 6, the voltage Vin on the power module 5 is stepped up, and according to Figure 7 The second voltage loop 4033 shown implements voltage closed-loop control.

[0084] Working mode 2: When the energy transfer direction is forward and the voltage Vin on the power module 5 is lower than the voltage Vo on the supercapacitor module 6, the conduction state of the power tube QF1 is set to 100% duty cycle state, the conduction state of the power tube QF2 is set to 0% duty cycle state, the power tube QR2 is used as a switch tube, the power tube QR1 is used as a freewheeling tube, and through Figure 7 The current loop subunit 402 shown in the figure realizes current closed-loop control, and the second voltage loop 4033 realizes voltage closed-loop control. Fig.10 As shown, the action sequence is to turn on the power tube QR2 first, and the current flows from the input capacitor Cin through the power tube QF1 and the inductor L, and then flows to the power tube QR2, and the inductor L completes the energy storage. When the power tube QR2 is turned off, due to the freewheeling characteristics of the inductor L current, the power tube QR1 completes the freewheeling, thereby realizing the forward transmission of energy. During the energy transmission process, the voltage Vin on the power module 5 is stepped up and converted according to Figure 7 The second voltage loop 4033 shown implements voltage closed-loop control.

[0085] Working mode three: When the energy transfer direction is reverse, and the voltage Vin on the power module 5 is lower than the voltage Vo on the supercapacitor module 6, the conduction state of the power tube QF1 is set to 100% duty cycle state, the conduction state of the power tube QF2 is set to 0% duty cycle state, the power tube QR1 is used as a switch tube, the power tube QR2 is used as a freewheeling tube, and through Figure 7The current loop subunit 402 shown in the figure implements current closed-loop control, and the first voltage loop 4032 implements voltage closed-loop control. Fig.11 As shown, the action sequence is to first turn on the power tube QR1, and the current flows from the output capacitor Co through the power tube QR1, the inductor L, the power tube QF1, and then flows to the input capacitor Cin, and the inductor L completes the energy storage. When the power tube QR1 is turned off, due to the freewheeling characteristics of the current of the inductor L, the power tube QR2 completes the freewheeling, thereby realizing the reverse transmission of energy. During the energy transmission process, the voltage Vo on the supercapacitor module 6 is first stepped down. When the voltage Vin on the power module 5 is equal to the voltage Vo on the supercapacitor module 6, the voltage Vo on the supercapacitor module 6 is stepped up, and according to Figure 7 The first voltage loop 4032 shown implements voltage closed-loop control.

[0086] Working mode 4: When the energy transfer direction is reverse and the voltage Vin on the power module 5 is higher than the voltage Vo on the supercapacitor module 6, the conduction state of the power tube QR1 is set to 100% duty cycle state, the conduction state of the power tube QR2 is set to 0% duty cycle state, the power tube QF2 is used as a switch tube, the power tube QF1 is used as a freewheeling tube, and through Figure 7 The current loop subunit 402 shown in the figure implements current closed-loop control, and the first voltage loop 4032 implements voltage closed-loop control. Fig.12 As shown in the figure, the action sequence is to turn on the power tube QF2 first, and the current flows from the output capacitor Co through the power tube QR1 and the inductor L, and then flows to the power tube QF1, and the inductor L completes the energy storage. When the power tube QF2 is turned off, due to the freewheeling characteristics of the inductor L current, the power tube QF1 completes the freewheeling, thereby realizing the reverse transmission of energy. During the energy transmission process, the voltage Vo on the supercapacitor module 6 is stepped up and converted according to Figure 7 The first voltage loop 4032 shown implements voltage closed-loop control.

[0087] As can be seen from the above, the present application allows the power tubes QF1 and QR1 to be 100% turned on, thereby reducing the power loss of the power tubes when turned on and off, and optimizing the system efficiency.

[0088] In summary, the bidirectional DC conversion circuit provided in the embodiment of the present application is symmetrical in circuit structure, and can realize bidirectional buck-boost conversion according to actual needs (such as temperature, control instructions), satisfying intelligent energy control. In the energy conversion process, there is voltage closed-loop control and current closed-loop control, so that the supercapacitor module 6 can be directly charged after being fully discharged, and the overall circuit architecture does not need to add pre-charging circuits and switching circuits, reducing the complexity and cost of circuit design.

[0089] The embodiment of the present application also provides a charger, including the bidirectional DC conversion circuit described above. Since the charger provided by the embodiment of the present application adopts all the technical solutions of all the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0090] The embodiment of the present application also provides a vehicle, including the bidirectional DC conversion circuit described above. Since the vehicle provided in the embodiment of the present application adopts all the technical solutions of all the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0091] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0092] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A bidirectional DC conversion circuit, characterized in that: It includes a first bridge arm module, a second bridge arm module, an energy storage module and a control module, wherein the first bridge arm module is respectively connected to the power supply module, the energy storage module and the control module, the second bridge arm module is respectively connected to the supercapacitor module, the energy storage module and the control module, and the control module is connected to the energy storage module; The control module is used to collect a first voltage, a second voltage and a first current, and control the on-off state of the first bridge arm module and the second bridge arm module according to the first voltage, the second voltage and the first current, so as to control the first current, and further control the storage or release of electric energy of the energy storage module; wherein the first voltage is the voltage on the power module, the second voltage is the voltage on the supercapacitor module, and the first current is the current flowing through the energy storage module.

2. The bidirectional DC conversion circuit according to claim 1, characterized in that: The control module is also used to connect with the vehicle controller; The control module is also used to obtain the control instructions output by the vehicle controller, and control the on and off states of the first bridge arm module and the second bridge arm module according to the control instructions, thereby controlling the storage or release of electric energy of the energy storage module.

3. The bidirectional DC conversion circuit according to claim 1, characterized in that: The bidirectional DC conversion circuit further includes a temperature acquisition module, which is connected to the control module and the super capacitor module respectively; The temperature acquisition module is used to acquire a first temperature and a second temperature, and transmit the first temperature and the second temperature to the control module; the control module is also used to control the on and off states of the first bridge arm module and the second bridge arm module according to the first temperature and the second temperature, thereby controlling the storage or release of electric energy of the energy storage module; wherein the first temperature is the temperature of the supercapacitor module, and the second temperature is the temperature of the environment in which the supercapacitor module is located.

4. The bidirectional DC conversion circuit according to any one of claims 1 to 3, characterized in that: The control module includes a control unit, a first drive unit and a second drive unit, the control unit is respectively connected to the first drive unit, the second drive unit, the energy storage module, the power supply module and the supercapacitor module, the first drive unit is connected to the first bridge arm module, and the second drive unit is connected to the second bridge arm module; The control unit is used to collect the first voltage, the second voltage and the first current, and output a first drive signal to the first drive unit according to the first voltage, the second voltage and the first current, and output a second drive signal to the second drive unit, so that the first drive unit controls the on-off state of the first bridge arm module according to the first drive signal, and the second drive unit controls the on-off state of the second bridge arm module according to the second drive signal, so as to control the first current, and further control the storage or release of electric energy of the energy storage module.

5. The bidirectional DC conversion circuit according to claim 4, characterized in that: The control unit includes a PWM generation subunit, a current loop subunit, a voltage loop subunit and a control subunit, wherein the current loop subunit is respectively connected to the energy storage module, the voltage loop subunit and the PWM generation subunit, the PWM generation subunit is respectively connected to the first drive unit, the second drive unit, the voltage loop subunit and the control subunit, and the control subunit is respectively connected to the voltage loop subunit, the vehicle controller, the temperature acquisition module, the power module and the supercapacitor module; The control subunit is used to output a first reference voltage and a second reference voltage, and is also used to output an energy transfer signal and a control signal according to the control instruction output by the vehicle controller, the first temperature and the second temperature output by the temperature acquisition module, and the collected first voltage and second voltage; the voltage loop subunit is used to output a first signal according to the energy transfer signal, the first reference voltage, the second reference voltage, and the collected first voltage and second voltage; the current loop subunit is used to output a second signal according to the first signal and the collected first current; The PWM generation subunit is used to output a first drive signal to the first drive unit and a second drive signal to the second drive unit according to the triangular wave signal, the second signal, the control signal and the energy transfer signal.

6. The bidirectional DC conversion circuit according to claim 5, characterized in that: The PWM generation subunit includes a PWM generator and a PWM controller, the PWM generator is connected to the current loop subunit and the PWM controller respectively, and the PWM controller is connected to the first drive unit, the second drive unit, the control subunit and the voltage loop subunit respectively; The PWM generator is used to output a PWM signal to the PWM controller according to the triangular wave signal and the second signal; the PWM controller is used to output a first drive signal to the first drive unit and a second drive signal to the second drive unit according to the energy transfer signal, the control signal and the PWM signal.

7. The bidirectional DC conversion circuit according to claim 5, characterized in that: The voltage loop subunit includes a voltage loop selector, a first voltage loop and a second voltage loop, the voltage loop selector is respectively connected to the first voltage loop, the second voltage loop, the current loop subunit, the PWM generation subunit and the control subunit, the first voltage loop is respectively connected to the power module and the control subunit, and the second voltage loop is respectively connected to the super capacitor module and the control subunit; the first signal includes a third signal and a fourth signal; The first voltage loop is used to output a third signal based on the first reference voltage and the collected first voltage; the second voltage loop is used to output a fourth signal based on the second reference voltage and the collected second voltage; the voltage loop selector is used to transmit the third signal or the fourth signal to the current loop sub-unit according to the energy transfer signal.

8. The bidirectional DC conversion circuit according to any one of claims 1 to 3, characterized in that: The energy storage module includes an energy storage unit and a current acquisition unit, the energy storage unit is respectively connected to the first bridge arm module and the current acquisition unit, and the current acquisition unit is respectively connected to the second bridge arm module and the control module; The current acquisition unit is used to acquire the first current and transmit the first current to the control module; The energy storage unit is used to store and release electric energy according to the first current.

9. A charger, characterized in that: It comprises the bidirectional DC conversion circuit as described in any one of claims 1 to 8.

10. A vehicle, characterized in that: It comprises the bidirectional DC conversion circuit as described in any one of claims 1 to 8.

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