DC-DC converter, power assembly and vehicle

Abstract

The invention discloses a DC-DC converter for a vehicle, a power assembly and the vehicle. The DC-DC converter comprises a full-bridge conversion circuit and an isolation conversion circuit, the full-bridge conversion circuit is configured to convert input first voltage into second voltage, the second voltage is larger than the first voltage, and the second voltage is used for supplying power to an engine controller and a driving motor controller of a vehicle; the isolation conversion circuit is connected with the full-bridge conversion circuit, the full-bridge conversion circuit is further configured to convert the input first voltage into third voltage with the isolation conversion circuit, the third voltage is smaller than the first voltage, and the third voltage is used for supplying power to a storage battery of the vehicle. According to the DC-DC converter, the same full-bridge conversion circuit for boosting and supplying power to the vehicle engine controller and the driving motor controller is multiplexed to carry out voltage reduction operation, so that components of a boosting direct-current converter and a voltage reduction direct-current converter are reduced, the circuit structure is simplified, and the space occupied by the direct-current converter is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of direct current converters, and more specifically, to a DC-DC converter, a powertrain and a vehicle for a vehicle. Background Art

[0002] In new energy vehicles, different DC converters are required to meet different power supply requirements. For example, a DC converter is provided to convert the high voltage of the power battery into a higher voltage, so as to power the motor controller after the voltage conversion. Another example is to provide a DC converter that converts the high voltage of the power battery into a low voltage to power the storage battery.

[0003] In the related art, multiple DC converters are independently arranged, occupying a large space, which is not conducive to the lightweight design of the vehicle. Summary of the invention

[0004] Embodiments of the present application provide a DC-DC converter, a powertrain, and a vehicle for a vehicle.

[0005] The embodiment of the present application provides a DC-DC converter for a vehicle, the DC-DC converter comprising:

[0006] a full-bridge conversion circuit, the full-bridge conversion circuit being configured to convert an input first voltage into a second voltage, the second voltage being greater than the first voltage, the second voltage being used to power an engine controller and a drive motor controller of the vehicle;

[0007] An isolation conversion circuit, the isolation conversion circuit is connected to the full-bridge conversion circuit, and the full-bridge conversion circuit is also configured to convert an input first voltage into a third voltage with the isolation conversion circuit, the third voltage is less than the first voltage, and the third voltage is used to power the battery of the vehicle.

[0008] In this way, in the DC-DC converter, powertrain and vehicle of the implementation mode of the present application, by reusing the same full-bridge conversion circuit that boosts the power supply to the vehicle engine controller and the drive motor controller for step-down operation, the components of the step-up DC converter and the step-down DC converter are reduced, the circuit structure is simplified, and the space occupied by the DC converter is reduced.

[0009] In some embodiments, the full-bridge conversion circuit includes a first bridge arm, a second bridge arm and a boost capacitor, the midpoint of the first bridge arm is electrically connected to the first end of the input source, the midpoint of the second bridge arm is electrically connected to the first end of the input source, the first endpoint of the first bridge arm and the first endpoint of the second bridge arm are electrically connected to the second end of the input source through the boost capacitor, the second endpoint of the first bridge arm and the second endpoint of the second bridge arm are electrically connected to the second end of the input source, the input source is configured to provide the first voltage, the two ends of the boost capacitor are the boost output ends of the full-bridge conversion circuit, and the boost output ends are configured to output the second voltage.

[0010] In this way, by boosting the first voltage through the full-bridge conversion circuit, a second voltage can be output across the boost capacitor to achieve conversion from the first voltage to the second voltage.

[0011] In some embodiments, the first bridge arm includes a first upper bridge arm switch tube and a first lower bridge arm switch tube, the second bridge arm includes a second upper bridge arm switch tube and a second lower bridge arm switch tube, the second pole of the first upper bridge arm switch tube is electrically connected to the first pole of the first lower bridge arm switch tube, and the connection point is the midpoint of the first bridge arm; the second pole of the second upper bridge arm switch tube is electrically connected to the first pole of the second lower bridge arm switch tube, and the connection point is the midpoint of the second bridge arm, the first pole of the first upper bridge arm switch tube is the first end point of the first bridge arm, the first pole of the second upper bridge arm switch tube is the first end point of the second bridge arm, the second pole of the first lower bridge arm switch tube is the second end point of the first bridge arm, and the second pole of the second lower bridge arm switch tube is the second end point of the second bridge arm.

[0012] In this way, by switching the on and off states of the four switch tubes, the voltage boost from the first voltage to the second voltage can be achieved.

[0013] In some embodiments, the on-time of the first upper bridge arm switch tube and the on-time of the first lower bridge arm switch tube are complementary, the on-time of the second upper bridge arm switch tube and the on-time of the second lower bridge arm switch tube are complementary, the duty cycle of the first lower bridge arm switch tube and the duty cycle of the second lower bridge arm switch tube are the same, and there is a target phase difference between the on-time of the first upper bridge arm switch tube and the on-time of the second upper bridge arm switch tube.

[0014] In this way, by setting the four switching tubes of the full-bridge conversion circuit to be alternately turned on according to preset rules, and setting the duty cycle and target phase value in the preset rules, the full-bridge conversion circuit can simultaneously boost and buck the first voltage, thereby realizing the multiplexing of the full-bridge conversion circuit.

[0015] In some embodiments, the duty cycle of the first lower bridge arm switch tube is used to adjust the voltage value of the second voltage, and the duty cycle of the first lower bridge arm switch tube is positively correlated with the voltage value of the second voltage.

[0016] In this way, by adjusting the duty cycle of the first lower bridge arm switch tube, the voltage value of the second voltage can be adjusted, thereby adjusting the boost ratio of the DC-DC converter. Moreover, when the second voltage needs to be adjusted, it can be achieved by adjusting the duty cycle of the first lower bridge arm switch tube.

[0017] In some embodiments, the duty cycle of the first lower bridge arm switch tube and the target phase difference are used to adjust the voltage value of the third voltage, and the duty cycle of the first lower bridge arm switch tube and the voltage value of the third voltage are positively correlated, and the target phase difference and the voltage value of the third voltage are positively correlated.

[0018] In this way, by adjusting the duty cycle and the target phase difference, the voltage value of the third voltage can be adjusted, thereby adjusting the step-down ratio of the DC-DC converter.

[0019] In some embodiments, the full-bridge conversion circuit also includes a first inductor, a second inductor and a first capacitor, the first capacitor is connected in parallel at both ends of the input source, the midpoint of the first bridge arm is electrically connected to the first end of the input source through the first inductor; the midpoint of the second bridge arm is electrically connected to the first end of the input source through the second inductor.

[0020] In this way, by providing the first inductor, the second inductor and the first capacitor, a boost circuit can be formed together with a plurality of switch tubes to achieve boosting of the first voltage.

[0021] In some embodiments, the isolation conversion circuit includes a transformer and a rectifier circuit, the full-bridge conversion circuit is connected to the primary of the transformer, the rectifier circuit is connected to the secondary of the transformer, and the rectifier circuit includes a step-down output terminal, and the step-down output terminal is used to output the third voltage.

[0022] In this way, by cooperating with the transformer and the rectifier circuit and the full-bridge conversion circuit, the first voltage of the input source can be stepped down to obtain direct current of the third voltage.

[0023] In some embodiments, a midpoint of the first bridge arm is connected to a first input port of the transformer primary; and a midpoint of the second bridge arm is connected to a second input port of the transformer primary.

[0024] In this way, by connecting the midpoint of the first bridge arm to the first input port of the transformer primary, and connecting the midpoint of the second bridge arm to the second input port of the transformer primary, the connection between the full-bridge conversion circuit and the isolation conversion circuit can be realized, so that the full-bridge conversion circuit and the isolation conversion circuit can jointly realize the step-down function. And by changing the on-off state of the switch tubes of the first bridge arm and the second bridge arm, the connection relationship between the first end of the input source and the two input ends of the isolation conversion circuit can be changed, thereby realizing the conversion of direct current to alternating current.

[0025] In some embodiments, the rectifier circuit includes a first rectifier switch tube and a second rectifier switch tube, the secondary of the transformer includes a first secondary winding and a second secondary winding, the first end of the first secondary winding is connected to the second end of the buck output end through the first rectifier switch tube, the second end of the first secondary winding and the first end of the second secondary winding are commonly connected to the first end of the buck output end, and the second end of the second secondary winding is connected to the second end of the buck output end through the second rectifier switch tube.

[0026] In this way, by controlling the first rectifier switch tube or the second rectifier switch tube to be turned on, the AC voltage output by the transformer can be rectified to obtain DC power.

[0027] In some embodiments, the first bridge arm includes a first upper bridge arm switch tube and a first lower bridge arm switch tube, the second bridge arm includes a second upper bridge arm switch tube and a second lower bridge arm switch tube, the first upper bridge arm switch tube, the first lower bridge arm switch tube, the positive pole of the input source and the first input port of the transformer primary are electrically connected, the second upper bridge arm switch tube, the second lower bridge arm switch tube, the positive pole of the input source and the second input port of the transformer primary are electrically connected, when the first lower bridge arm switch tube and the second upper bridge arm switch tube are turned on at the same time, the first rectifier switch tube is turned on, and when the first upper bridge arm switch tube and the second lower bridge arm switch tube are turned on at the same time, the second rectifier switch tube is turned on.

[0028] In this way, by controlling the first rectifier switch tube to be turned on when the first lower bridge arm switch tube and the second upper bridge arm switch tube are turned on at the same time, and the second rectifier switch tube to be turned on when the first upper bridge arm switch tube and the second lower bridge arm switch tube are turned on at the same time, the conversion of the alternating current output by the transformer can be achieved.

[0029] An embodiment of the present application provides a powertrain, which includes a DC-DC converter as described in any of the above embodiments.

[0030] An embodiment of the present application provides a vehicle, which includes a DC-DC converter as described in any of the above embodiments, or a powertrain as described in the above embodiments.

[0031] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0033] Figure 1 It is one of the circuit diagrams of the input source and the DC-DC converter of certain embodiments of the present application;

[0034] Figure 2 This is the second circuit diagram of the input source and DC-DC converter of certain embodiments of the present application;

[0035] Figure 3 is a schematic diagram of an input source, a DC-DC converter and a load in certain embodiments of the present application;

[0036] Figure 4 It is a timing diagram of the switch tube in certain embodiments of the present application. DETAILED DESCRIPTION

[0037] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0038] In new energy vehicles, different DC converters are required to meet different power supply requirements. For example, a DC converter is provided to convert the high voltage of the power battery into a higher voltage, so as to power the motor controller after the voltage conversion. Another example is to provide a DC converter that converts the high voltage of the power battery into a low voltage to power the storage battery.

[0039] In the related art, multiple DC converters are independently arranged, occupying a large space, which is not conducive to the lightweight design of the vehicle.

[0040] Based on the above unresolved issues, please refer to Figure 1 and Figure 2 The embodiment of the present application provides a DC-DC converter 1000 for a vehicle, and the DC-DC converter 1000 includes:

[0041] A full-bridge conversion circuit 100, the full-bridge conversion circuit 100 is configured to convert an input first voltage into a second voltage, the second voltage is greater than the first voltage, and the second voltage is used to power an engine controller and a drive motor controller of a vehicle;

[0042] The isolation conversion circuit 300 is connected to the full-bridge conversion circuit 100. The full-bridge conversion circuit 100 is also configured to convert the input first voltage into a third voltage with the isolation conversion circuit 300. The third voltage is less than the first voltage. The third voltage is used to power the battery of the vehicle.

[0043] Specifically, the DC-DC converter 1000 is a DC-DC converter for converting the voltage of direct current. The full-bridge conversion circuit 100 is connected to the input source 3000, and can be used to convert the direct current of the first voltage of the input source 3000 into the direct current of the second voltage to achieve voltage conversion. The full-bridge conversion circuit 100 can also be connected to the isolation conversion circuit 300, and together with it, the direct current of the first voltage of the input source 3000 is converted into the direct current of the third voltage to achieve voltage conversion.

[0044] Among them, the second voltage is greater than the first voltage, and the full-bridge conversion circuit 100 can realize high-voltage conversion alone. The third voltage is less than the first voltage, and the full-bridge conversion circuit 100 and the isolation conversion circuit 300 can realize low-voltage conversion together. By multiplexing the full-bridge conversion circuit 100, the DC-DC converter 1000 can realize the boost and buck functions at the same time.

[0045] In certain embodiments, see Figure 3 , the input source 3000 is a power battery of the vehicle. The input end of the full-bridge conversion circuit 100 is connected to the power battery, and the boost output end of the full-bridge conversion circuit 100 is connected to the drive motor controller and the generator controller, the drive motor controller is connected to the drive motor, and the generator controller is connected to the generator. The full-bridge conversion circuit 100 can convert the DC power of the first voltage of the power battery into a second voltage, and then output it to the drive motor controller and the generator controller to control the operation of the drive motor and the generator.

[0046] The step-down output end of the full-bridge conversion circuit 100 is connected to the input end of the isolation conversion unit, and the output end of the isolation conversion unit is connected to the battery. The full-bridge conversion circuit 100 and the isolation conversion unit jointly convert the DC power of the first voltage of the power battery into a third voltage, and then output it to the battery to power the battery. Among them, the boost output end is the two ends of the boost capacitor C2, that is, the subsequent boost load is connected in parallel with the boost capacitor C2. The step-down output end is the two ends of the resonant capacitor C3, that is, the subsequent step-down load is connected in parallel with the resonant capacitor C3.

[0047] Among them, the first voltage of the power battery is increased to the second voltage, and the second voltage is used to power the generator controller and the drive motor controller. By increasing the voltage of the generator controller and the drive motor controller, the power of power generation and drive motor is increased. Since P = UI, when the power is constant, the higher the voltage, the lower the current. Therefore, increasing the voltage can also reduce the current to meet the requirements of high-voltage wiring harnesses and connectors.

[0048] In one embodiment, the isolation conversion circuit 300 includes a transformer 310. The full-bridge conversion circuit 100 converts the direct current of the first voltage into alternating current, and outputs it to the transformer 310 of the isolation conversion circuit 300. The transformer 310 performs voltage conversion on the alternating current to reduce the voltage of the alternating current. The isolation conversion circuit 300 then converts the alternating current after the voltage reduction into direct current, and outputs it to the subsequent circuit to reduce the voltage of the direct current. Since the full-bridge conversion circuit 100 performs direct current conversion when boosting, and the full-bridge conversion circuit 100 performs direct current to alternating current conversion when reducing the voltage, there is no conflict between the two, so the DC-DC converter 1000 can perform boosting and bucking at the same time to meet the working conditions where there are both boosting and bucking requirements.

[0049] In this way, in the DC-DC converter 1000, powertrain and vehicle of the embodiment of the present application, by reusing the same full-bridge conversion circuit 100 that boosts the power supply to the vehicle engine controller and the drive motor controller for step-down operation, the components of the step-up DC converter and the step-down DC converter are reduced, the circuit structure is simplified, and the space occupied by the DC converter is reduced.

[0050] See also Figure 1 In some embodiments, the full-bridge conversion circuit 100 includes a first bridge arm 110, a second bridge arm 130 and a boost capacitor 140, the midpoint of the first bridge arm 110 is electrically connected to the first end of the input source 3000, the midpoint of the second bridge arm 130 is electrically connected to the first end of the input source 3000, the first end point of the first bridge arm 110 and the first end point of the second bridge arm 130 are electrically connected to the second end of the input source 3000 through the boost capacitor 140, the second end point of the first bridge arm 110 and the second end point of the second bridge arm 130 are electrically connected to the second end of the input source 3000, the input source 3000 is configured to provide a first voltage, the two ends of the boost capacitor 140 are boost output ends of the full-bridge conversion circuit 100, and the boost output end is configured to output a second voltage.

[0051] Specifically, the first end of the input source 3000 includes the positive or negative pole of the input source 3000, and the second end of the input source 3000 includes the negative or positive pole of the input source 3000. This embodiment is described with the first end of the input source 3000 as the positive pole and the second end as the negative pole.

[0052] The midpoint of the first bridge arm 110 is electrically connected to the first end of the input source 3000, and the midpoint of the second bridge arm 130 is electrically connected to the first end of the input source 3000. In other words, the midpoint of the first bridge arm 110 is connected to the positive electrode of the input source 3000, and the midpoint of the second bridge arm 130 is connected to the positive electrode of the input source 3000.

[0053] The first end point of the first bridge arm 110 and the first end point of the second bridge arm 130 are electrically connected to the negative electrode of the input source 3000 through the boost capacitor 140. The second end point of the first bridge arm 110 and the second end point of the second bridge arm 130 are electrically connected to the negative electrode of the input source 3000. The two ends of the boost capacitor 140 are the boost output ends of the full-bridge conversion circuit 100, which are used to output the second voltage. In other words, the second voltage is the voltage across the two ends of the boost capacitor 140.

[0054] In this way, by boosting the first voltage through the full-bridge conversion circuit 100 , a second voltage can be output across the boost capacitor 140 to achieve conversion from the first voltage to the second voltage.

[0055] See also Figure 2 In some embodiments, the first bridge arm 110 includes a first lower bridge arm switch tube 111 and a first upper bridge arm switch tube 113, and the second bridge arm 130 includes a second lower bridge arm switch tube 131 and a second upper bridge arm switch tube 133. The second pole of the first upper bridge arm switch tube 113 is electrically connected to the first pole of the first lower bridge arm switch tube 111, and the connection point is the midpoint of the first bridge arm 110; the second pole of the second upper bridge arm switch tube 133 is electrically connected to the first pole of the second lower bridge arm switch tube 131, and the connection point is the midpoint of the second bridge arm 130, the first pole of the first upper bridge arm switch tube 113 is the first end point of the first bridge arm 110, the first pole of the second upper bridge arm switch tube 133 is the first end point of the second bridge arm 130, the second pole of the first lower bridge arm switch tube 111 is the second end point of the first bridge arm 110, and the second pole of the second lower bridge arm switch tube 131 is the second end point of the second bridge arm 130.

[0056] Specifically, the first pole of the first upper bridge arm switch tube Q1 is the first end point of the first bridge arm 110, the first pole of the second upper bridge arm switch tube Q3 is the first end point of the second bridge arm 130, the second pole of the first lower bridge arm switch tube Q2 is the second end point of the first bridge arm 110, and the second pole of the second lower bridge arm switch tube Q4 is the second end point of the second bridge arm 130.

[0057] The first electrode of the first upper bridge arm switch tube Q1 and the first electrode of the second upper bridge arm switch tube Q3 are connected to the negative electrode of the input source 3000 through the boost capacitor 140. The second electrode of the first lower bridge arm switch tube Q2 and the second lower bridge arm switch tube Q4 are directly connected to the negative electrode of the input source 3000.

[0058] The second electrode of the first upper bridge arm switch tube Q1 is connected to the first electrode of the first lower bridge arm to form the midpoint of the first bridge arm 110. The second electrode of the second upper bridge arm switch tube Q3 is connected to the first electrode of the second lower bridge arm to form the midpoint of the second bridge arm 130.

[0059] The first electrode of the first lower bridge arm switch tube Q2 is connected to the positive electrode of the input source 3000 through the first inductor 150, and the first electrode of the second lower bridge arm switch tube Q4 is connected to the positive electrode of the input source 3000 through the second inductor 170. The second electrode of the first lower bridge arm switch tube Q2 and the second electrode of the second lower bridge arm switch tube Q4 are commonly connected to the negative electrode of the input source 3000. The second electrode of the first lower bridge arm switch tube Q2 and the second electrode of the second lower bridge arm switch tube Q4 are commonly connected to one end of the boost capacitor 140.

[0060] The full-bridge conversion unit further includes a first capacitor C1, which is connected in parallel between the positive electrode and the negative electrode of the input source 3000. The first electrode of the first lower bridge arm switch tube Q2 is connected to the first end of the first capacitor C1 through the first inductor 150, and the first electrode of the second lower bridge arm switch tube Q4 is connected to the positive electrode of the input source 3000 through the second inductor 170. The second electrode of the first lower bridge arm switch tube Q2 and the second electrode of the second lower bridge arm switch tube Q4 are commonly connected to the second end of the first capacitor C1.

[0061] In this way, by switching the on and off states of the four switch tubes, the voltage boost from the first voltage to the second voltage can be achieved.

[0062] See also Figure 4 In some embodiments, the on-time of the first upper arm switch tube 113 is complementary to the on-time of the first lower arm switch tube 111, the on-time of the second upper arm switch tube 133 is complementary to the on-time of the second lower arm switch tube 131, the duty cycle of the first lower arm switch tube 111 is the same as the duty cycle of the second lower arm switch tube 131, and there is a target phase difference between the on-time of the first upper arm switch tube 113 and the on-time of the second upper arm switch tube 133.

[0063] Specifically, the conduction time of the first upper bridge arm switch tube Q1 is complementary to the conduction time of the first lower bridge arm switch tube Q2, that is, the control signal of the first upper bridge arm switch tube Q1 is complementary to the control signal of the first lower bridge arm switch tube Q2, so as to avoid the first bridge arm 110 being fully turned on and causing a short circuit at the boost output terminal. The conduction time of the second upper bridge arm switch tube Q3 is complementary to the conduction time of the second lower bridge arm switch tube Q4, that is, the control signal of the second upper bridge arm switch tube Q3 is complementary to the control signal of the second lower bridge arm switch tube Q4, so as to avoid the second bridge arm 130 being fully turned on and causing a short circuit at the boost output terminal.

[0064] The duty cycle of the first lower bridge arm switch tube Q2 is the same as the duty cycle D of the second lower bridge arm switch tube Q4, and the duty cycle D of the first lower bridge arm switch tube Q2 is used to adjust the voltage value of the second voltage, that is, the voltage value of the second voltage can be adjusted by adjusting the duty cycle D of the first lower bridge arm switch tube Q2.

[0065] Since the duty cycle D of the first lower bridge arm switch tube Q2 is the same as that of the second lower bridge arm switch tube Q4, and the conduction time of the first lower bridge arm switch tube Q2 and the first upper bridge arm switch tube Q1 is complementary, and the conduction time of the second lower bridge arm switch tube Q4 and the second upper bridge arm switch tube Q3 is complementary, the duty cycle of the first upper bridge arm switch tube Q1 and the second upper bridge arm switch tube Q3 is the same. However, the first upper bridge arm switch tube Q1 and the second upper bridge arm switch tube Q3 are not turned on at the same time, that is, there is a target phase difference ψ between the turn-on time of the first upper bridge arm switch tube Q1 and the turn-on time of the second upper bridge arm switch tube Q3.

[0066] By setting the duty cycle of the first lower bridge arm switch tube Q4 and the target phase difference ψ between the first upper bridge arm switch tube Q1 and the second upper bridge arm switch tube Q3, it is possible to simultaneously boost the first voltage to the second voltage and step down the first voltage to the third voltage.

[0067] In this way, by setting the four switching tubes of the full-bridge conversion circuit 100 to be alternately turned on according to preset rules, and setting the duty cycle and target phase value in the preset rules, the full-bridge conversion circuit 100 can simultaneously achieve boosting and bucking of the first voltage, thereby realizing the multiplexing of the full-bridge conversion circuit 100.

[0068] In some embodiments, the duty cycle of the first lower bridge arm switch tube 111 is used to adjust the voltage value of the second voltage, and the duty cycle of the first lower bridge arm switch tube 111 is positively correlated with the voltage value of the second voltage.

[0069] Specifically, the voltage value of the second voltage can be adjusted by adjusting the duty cycle D of the first lower bridge arm switch tube 111. And the duty cycle D of the first lower bridge arm switch tube 111 is positively correlated with the voltage value of the second voltage, that is, when the duty cycle of the first lower bridge arm switch tube 111 is larger, the voltage value of the second voltage converted by the full-bridge conversion circuit 100 is larger; when the duty cycle of the first lower bridge arm switch tube 111 is smaller, the voltage value of the second voltage converted by the full-bridge conversion circuit 100 is smaller.

[0070] In one embodiment, the relationship between the first voltage U1, the second voltage U2 and the duty cycle D is:

[0071]

[0072] In addition, the voltage value of the third voltage is also related to the turn ratio T of the transformer 310 , and the ratio U3 / U1 of the third voltage to the first voltage is negatively correlated to the turn ratio T of the transformer 310 .

[0073] In one embodiment, the first voltage input by the input source 3000 has a value range of 250 V to 500 V, and the third voltage is 14 V. The turns ratio of the transformer 310 is set to 17:1:1 (primary winding turns: first secondary winding turns: second secondary winding turns).

[0074] In another embodiment, the first voltage input by the input source 3000 has a value range of 400 V to 750 V, and the third voltage is 14 V. Then the turns ratio of the transformer 310 is set to 28:1:1.

[0075] In this way, by adjusting the duty cycle of the first lower bridge arm switch tube 111, the voltage value of the second voltage can be adjusted, thereby adjusting the boost ratio of the DC-DC converter 1000. Moreover, when the second voltage needs to be adjusted, it can be achieved by adjusting the duty cycle of the first lower bridge arm switch tube 111.

[0076] In some embodiments, the duty cycle and target phase difference of the first lower bridge arm switch tube 111 are used to adjust the voltage value of the third voltage, and the duty cycle of the first lower bridge arm switch tube 111 and the voltage value of the third voltage are positively correlated, and the target phase difference and the voltage value of the third voltage are positively correlated.

[0077] Specifically, the target phase difference ψ is the phase difference between the control signal of the first upper bridge arm switch tube Q1 and the control signal of the second upper bridge arm switch tube Q3, and the target phase difference ψ can be used to adjust the voltage value of the third voltage. In addition, the duty cycle of the first lower bridge arm switch tube 111 is positively correlated with the voltage value of the third voltage. In other words, the larger the duty cycle, the larger the voltage value of the third voltage.

[0078] At the same time, the target phase difference and the voltage value of the third voltage are positively correlated. That is, the larger the target phase difference, the larger the voltage value of the third voltage.

[0079] In one embodiment, the relationship between the third voltage and the first voltage is:

[0080]

[0081] Wherein, T is the turns ratio of the transformer 310 of the isolation conversion circuit 300, and D is the duty cycle of the first lower bridge arm switch tube Q2.

[0082] In this way, by adjusting the duty cycle and the target phase difference, the voltage value of the third voltage can be adjusted, thereby adjusting the voltage reduction ratio of the DC-DC converter 1000 .

[0083] In some embodiments, the full-bridge conversion circuit 100 also includes a first inductor 150, a second inductor 170 and a first capacitor 190, the first capacitor 190 is connected in parallel at both ends of the input source 3000, the midpoint of the first bridge arm 110 is electrically connected to the first end of the input source 3000 through the first inductor 150; the midpoint of the second bridge arm 130 is electrically connected to the first end of the input source 3000 through the second inductor 170.

[0084] Specifically, the first electrode of the first upper bridge arm switch tube Q1 and the first electrode of the second upper bridge arm switch tube Q3 are commonly connected to the first end of the boost capacitor 140, the second electrode of the first upper bridge arm switch tube Q1 is connected to the positive electrode of the input source 3000 and the first end of the first capacitor C1 through the first inductor L1, and the second electrode of the second upper bridge arm switch tube Q3 is connected to the positive electrode of the input source 3000 and the first end of the first capacitor C1 through the second inductor 170L2. The second electrode of the first upper bridge arm switch tube Q1 is connected to the first electrode of the first lower bridge arm switch tube Q2, and the second electrode of the second upper bridge arm switch tube Q3 is connected to the first electrode of the second lower bridge arm switch tube Q4.

[0085] When the first lower bridge arm switch tube Q2 is turned on, the first inductor 150 is used to store energy; when the first upper bridge arm switch tube Q1 is turned on, the first inductor 150 is used to release energy. When the second lower bridge arm switch tube Q4 is turned on, the second inductor 170 is used to store energy; when the second upper bridge arm switch tube Q3 is turned on, the second inductor 170 is used to release energy. The first inductor 150 and the second inductor 170 release energy alternately to achieve a DC voltage boost.

[0086] In addition, the control electrodes of the first upper bridge arm switch tube Q1, the first lower bridge arm switch tube Q2, the second upper bridge arm switch tube Q3 and the second lower bridge arm switch tube Q4 are connected to the controller to receive the control signal output by the controller and switch the on-off state according to the control signal.

[0087] In this way, by providing the first inductor 150 , the second inductor 170 and the first capacitor 190 , a boost circuit can be formed together with a plurality of switch tubes to achieve boosting of the first voltage.

[0088] In some embodiments, the isolation conversion circuit 300 includes a transformer 310 and a rectifier circuit 330, the full-bridge conversion circuit 100 is connected to the primary of the transformer 310, the rectifier circuit 330 is connected to the secondary of the transformer 310, and the rectifier circuit 330 includes a step-down output terminal, which is used to output a third voltage.

[0089] Specifically, the primary of the transformer 310 is connected to the full-bridge conversion circuit 100 to receive the AC power converted by the full-bridge conversion circuit 100. The transformer 310 of the isolation conversion circuit 300 is used to step down the AC power converted by the full-bridge conversion circuit 100 and transmit it to the secondary. The rectifier circuit 330 is connected to the secondary of the transformer 310 to receive the stepped-down AC power. The rectifier circuit 330 is used to rectify the stepped-down AC power into a DC power of a third voltage and output it, thereby completing the step-down process of the first voltage.

[0090] In this way, by cooperating with the transformer 310 and the rectifier circuit 330 and the full-bridge converter circuit 100, the first voltage of the input source 3000 can be stepped down to obtain a direct current of a third voltage.

[0091] In some embodiments, a midpoint of the first bridge arm 110 is connected to a first input port of the primary of the transformer 310 ; a midpoint of the second bridge arm 130 is connected to a second input port of the primary of the transformer 310 .

[0092] In addition, the midpoint of the first bridge arm 110 is the connection point of the first upper bridge arm switch tube Q1 and the first lower bridge arm switch tube Q2, and the midpoint of the second bridge arm 130 is the connection point of the second upper bridge arm switch tube Q3 and the second lower bridge arm switch tube Q4.

[0093] The midpoint of the first bridge arm 110 is connected to the first input port of the primary of the transformer 310, so that the first upper bridge arm switch tube Q1 and the first lower bridge arm switch tube Q2 are connected to the first input port of the primary of the transformer 310. The midpoint of the second bridge arm 130 is connected to the second input port of the primary of the transformer 310, so that the second upper bridge arm switch tube Q3 and the second lower bridge arm switch tube Q4 are connected to the second input port of the primary of the transformer 310, so as to realize the connection between the full-bridge conversion circuit 100 and the transformer 310.

[0094] The midpoint of the first bridge arm 110 is connected to the first input terminal of the isolation conversion circuit 300, that is, connected to the first input port of the primary of the transformer 310. The midpoint of the first bridge arm 110 is connected to the positive electrode of the input source 3000, so that the first input terminal of the isolation conversion circuit 300 is connected to the positive electrode of the input source 3000.

[0095] The midpoint of the second bridge arm 130 is connected to the second input terminal of the isolation conversion circuit 300, that is, connected to the second input port of the primary of the transformer 310. And the midpoint of the second bridge arm 130 is connected to the positive electrode of the input source 3000, so that the second input terminal of the isolation conversion circuit 300 can be connected to the positive electrode of the input source 3000.

[0096] When the switch tube of the first bridge arm 110 is turned on, the midpoint of the first bridge arm 110 is connected to the first end point, or the midpoint of the first bridge arm 110 is connected to the second end point of the first bridge arm 110, so that the first input end point of the isolation conversion circuit 300 is connected to the negative pole of the input source 3000.

[0097] When the switch tube of the second bridge arm 130 is turned on, the midpoint of the second bridge arm 130 is connected to the first end point, or the midpoint of the second bridge arm 130 is connected to the second end point of the second bridge arm 130, so that the second input end point of the isolation conversion circuit 300 is connected to the negative pole of the input source 3000.

[0098] When the first upper bridge arm switch tube Q1 is closed and the second lower bridge arm switch tube Q4 is closed, the first input terminal of the transformer 310 is connected to the negative electrode of the input source 3000 , and the second input terminal of the transformer 310 is connected to the positive electrode of the input source 3000 .

[0099] When the first lower bridge arm switch tube Q2 is closed and the second upper bridge arm switch tube Q3 is closed, the first input terminal of the transformer 310 is connected to the positive electrode of the input source 3000 , and the second input terminal of the transformer 310 is connected to the negative electrode of the input source 3000 .

[0100] In this way, by connecting the midpoint of the first bridge arm 110 to the first input port of the primary of the transformer 310, and connecting the midpoint of the second bridge arm 130 to the second input port of the primary of the transformer 310, the connection between the full-bridge conversion circuit 100 and the isolation conversion circuit 300 can be realized, so that the full-bridge conversion circuit 100 and the isolation conversion circuit 300 can jointly realize the step-down function. And by changing the on-off state of the switch tubes of the first bridge arm 110 and the second bridge arm 130, the connection relationship between the first end of the input source 3000 and the two input ends of the isolation conversion circuit 300 can be changed, thereby realizing the conversion of direct current to alternating current.

[0101] In some embodiments, the rectifier circuit 330 includes a first rectifier switch tube 311 and a second rectifier switch tube 313, and the secondary of the transformer 310 includes a first secondary winding and a second secondary winding, the first end of the first secondary winding is connected to the second end of the buck output terminal through the first rectifier switch tube 311, the second end of the first secondary winding and the first end of the second secondary winding are commonly connected to the first end of the buck output terminal, and the second end of the second secondary winding is connected to the second end of the buck output terminal through the second rectifier switch tube 313.

[0102] Specifically, a first end of the buck output terminal is connected to a second end of the first secondary winding and a first end of the second secondary winding.

[0103] The first pole of the first rectifier switch tube Q5 is connected to the first end of the first secondary winding, and the second pole of the first rectifier switch tube Q5 is connected to the second end of the buck output terminal. When the first rectifier switch tube Q5 is turned on, the first end of the first secondary winding and the second end of the buck output terminal are electrically connected to form a first loop.

[0104] The first pole of the second rectifier switch tube Q6 is connected to the second end of the second secondary winding, and the second pole of the second rectifier switch tube Q6 is connected to the second end of the buck output terminal. When the second rectifier switch tube Q6 is turned on, the second end of the second secondary winding and the second end of the buck output terminal are electrically connected to form a second loop.

[0105] In addition, the control electrode of the first rectifier switch tube Q5 and the control electrode of the second rectifier switch tube Q6 are connected to the controller to receive the control signal output by the controller and switch on and off according to the control signal.

[0106] In the case where the direction of the voltage at the primary of the transformer 310 is from the first end to the second end, if the first rectifier switch tube Q5 is turned on, the direction of the voltage at the step-down output end is from bottom to top, and if the second rectifier switch tube Q6 is turned on, the direction of the voltage at the step-down output end is from bottom to top. Therefore, by controlling the first rectifier switch tube Q5 or the second rectifier switch tube Q6 to be turned on, the direction of the voltage output at the step-down output end can be changed. In order to make the output third voltage a DC voltage with a constant voltage direction, the first rectifier switch tube Q5 or the second rectifier switch tube Q6 can be controlled to be turned on according to the direction of the AC power transmitted by the transformer 310 to achieve the conversion of AC power into DC power.

[0107] In this way, by controlling the first rectifying switch tube 311 or the second rectifying switch tube 313 to be turned on, the alternating current voltage output by the transformer 310 can be rectified to obtain direct current.

[0108] In some embodiments, the first bridge arm 110 includes a first upper bridge arm switch tube 113 and a first lower bridge arm switch tube 111, and the second bridge arm 130 includes a second upper bridge arm switch tube 133 and a second lower bridge arm switch tube 131. The first upper bridge arm switch tube 113, the first lower bridge arm switch tube 111, the positive electrode of the input source 3000, and the first input port of the primary of the transformer 310 are electrically connected. The second upper bridge arm switch tube 133, the second lower bridge arm switch tube 131, the positive electrode of the input source 3000, and the second input port of the primary of the transformer 310 are electrically connected. When the first lower bridge arm switch tube 111 and the second upper bridge arm switch tube 133 are turned on at the same time, the first rectifier switch tube 311 is turned on. When the first upper bridge arm switch tube 113 and the second lower bridge arm switch tube 131 are turned on at the same time, the second rectifier switch tube 313 is turned on.

[0109] Specifically, when the second upper bridge arm switch tube Q3 and the first lower bridge arm switch tube Q2 are turned on at the same time, the direction of the voltage of the primary of the transformer 310 is from the second input port of the primary of the transformer 310 to the first input port (from bottom to top). At this time, the first rectifier switch tube Q5 is controlled to be turned on, so that the rectifier circuit 330 forms a first loop, the buck output end is connected to the first secondary winding, and the direction of the DC power outputted by the buck output end is from the second input port of the buck output end to the first input port (from bottom to top).

[0110] When the first upper bridge arm switch tube Q1 and the second lower bridge arm switch tube Q4 are turned on at the same time, the direction of the voltage of the primary of the transformer 310 is from the first input port of the primary of the transformer 310 to the second input port (from top to bottom). At this time, the second rectifier switch tube Q6 is controlled to be turned on, so that the rectifier circuit 330 forms a second loop, the buck output end and the second secondary winding are connected, and the direction of the DC power outputted by the buck output end is from the first input port of the buck output end to the second input port (from top to bottom).

[0111] In addition, the time when the second upper arm switch tube Q3 and the first lower arm switch tube Q2 are turned on at the same time, and the time when the first upper arm switch tube Q1 and the second lower arm switch tube Q4 are turned on at the same time, are both determined according to the target phase difference. Therefore, the turn-on time of the first rectifier switch tube Q5 and the second rectifier switch tube Q6 is determined according to the target phase difference.

[0112] In this way, by controlling the first rectifier switch tube 311 to be turned on when the first lower bridge arm switch tube 111 and the second upper bridge arm switch tube 133 are turned on at the same time, and the second rectifier switch tube 313 to be turned on when the first upper bridge arm switch tube 113 and the second lower bridge arm switch tube 131 are turned on at the same time, the conversion of the alternating current output by the transformer 310 can be achieved.

[0113] In some embodiments, the rectifier circuit 330 further includes a resonance unit, and the resonance unit includes a resonance capacitor C3 and a resonance inductor L3 to filter the direct current of the third voltage.

[0114] An embodiment of the present application provides a powertrain, which includes a DC-DC converter 1000 as described in any of the above embodiments.

[0115] An embodiment of the present application provides a vehicle, the vehicle comprising a DC-DC converter 1000 as in any of the above embodiments, or a powertrain as in the above embodiments.

[0116] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0117] In addition, the term "connection" should be understood in a broad sense, for example, it can include fixed connection, detachable connection, or integral connection; it can include direct connection, indirect connection through an intermediate medium, and internal communication between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0118] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0119] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0120] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A DC-DC converter for a vehicle, characterized in that: The DC-DC converter comprises: a full-bridge conversion circuit, the full-bridge conversion circuit being configured to convert an input first voltage into a second voltage, the second voltage being greater than the first voltage, the second voltage being used to power an engine controller and a drive motor controller of the vehicle; An isolation conversion circuit, the isolation conversion circuit is connected to the full-bridge conversion circuit, and the full-bridge conversion circuit is also configured to convert an input first voltage into a third voltage with the isolation conversion circuit, the third voltage is less than the first voltage, and the third voltage is used to power the battery of the vehicle.

2. The DC-DC converter according to claim 1, characterized in that: The full-bridge conversion circuit includes a first bridge arm, a second bridge arm and a boost capacitor, the midpoint of the first bridge arm is electrically connected to the first end of the input source, the midpoint of the second bridge arm is electrically connected to the first end of the input source, the first endpoint of the first bridge arm and the first endpoint of the second bridge arm are electrically connected to the second end of the input source through the boost capacitor, the second endpoint of the first bridge arm and the second endpoint of the second bridge arm are electrically connected to the second end of the input source, the input source is configured to provide the first voltage, the two ends of the boost capacitor are the boost output ends of the full-bridge conversion circuit, and the boost output ends are configured to output the second voltage.

3. The DC-DC converter according to claim 2, characterized in that: The first bridge arm includes a first upper bridge arm switch tube and a first lower bridge arm switch tube, and the second bridge arm includes a second upper bridge arm switch tube and a second lower bridge arm switch tube. The second pole of the first upper bridge arm switch tube is electrically connected to the first pole of the first lower bridge arm switch tube, and the connection point is the midpoint of the first bridge arm; the second pole of the second upper bridge arm switch tube is electrically connected to the first pole of the second lower bridge arm switch tube, and the connection point is the midpoint of the second bridge arm, the first pole of the first upper bridge arm switch tube is the first end point of the first bridge arm, the first pole of the second upper bridge arm switch tube is the first end point of the second bridge arm, the second pole of the first lower bridge arm switch tube is the second end point of the first bridge arm, and the second pole of the second lower bridge arm switch tube is the second end point of the second bridge arm.

4. The DC-DC converter according to claim 3, characterized in that: The on-time of the first upper bridge arm switch tube is complementary to the on-time of the first lower bridge arm switch tube, the on-time of the second upper bridge arm switch tube is complementary to the on-time of the second lower bridge arm switch tube, the duty cycle of the first lower bridge arm switch tube is the same as the duty cycle of the second lower bridge arm switch tube, and there is a target phase difference between the on-time of the first upper bridge arm switch tube and the on-time of the second upper bridge arm switch tube.

5. The DC-DC converter according to claim 4, characterized in that: The duty cycle of the first lower bridge arm switch tube is used to adjust the voltage value of the second voltage, and the duty cycle of the first lower bridge arm switch tube is positively correlated with the voltage value of the second voltage.

6. The DC-DC converter according to claim 4, characterized in that: The duty cycle of the first lower bridge arm switch tube and the target phase difference are used to adjust the voltage value of the third voltage, and the duty cycle of the first lower bridge arm switch tube and the voltage value of the third voltage are positively correlated, and the target phase difference and the voltage value of the third voltage are positively correlated.

7. The DC-DC converter according to claim 2, characterized in that: The full-bridge conversion circuit also includes a first inductor, a second inductor and a first capacitor, the first capacitor is connected in parallel to the two ends of the input source, the midpoint of the first bridge arm is electrically connected to the first end of the input source through the first inductor; the midpoint of the second bridge arm is electrically connected to the first end of the input source through the second inductor.

8. The DC-DC converter according to claim 2, characterized in that: The isolation conversion circuit includes a transformer and a rectifier circuit, the full-bridge conversion circuit is connected to the primary of the transformer, the rectifier circuit is connected to the secondary of the transformer, and the rectifier circuit includes a step-down output terminal, which is used to output the third voltage.

9. The DC-DC converter according to claim 8, characterized in that: The midpoint of the first bridge arm is connected to the first input port of the primary of the transformer; the midpoint of the second bridge arm is connected to the second input port of the primary of the transformer.

10. The DC-DC converter according to claim 8, characterized in that: The rectifier circuit includes a first rectifier switch tube and a second rectifier switch tube, the secondary of the transformer includes a first secondary winding and a second secondary winding, the first end of the first secondary winding is connected to the second end of the buck output end through the first rectifier switch tube, the second end of the first secondary winding and the first end of the second secondary winding are commonly connected to the first end of the buck output end, and the second end of the second secondary winding is connected to the second end of the buck output end through the second rectifier switch tube.

11. The DC-DC converter according to claim 10, characterized in that: The first bridge arm includes a first upper bridge arm switch tube and a first lower bridge arm switch tube, the second bridge arm includes a second upper bridge arm switch tube and a second lower bridge arm switch tube, the first upper bridge arm switch tube, the first lower bridge arm switch tube, the positive pole of the input source and the first input port of the primary of the transformer are electrically connected, the second upper bridge arm switch tube, the second lower bridge arm switch tube, the positive pole of the input source and the second input port of the primary of the transformer are electrically connected, when the first lower bridge arm switch tube and the second upper bridge arm switch tube are turned on at the same time, the first rectifier switch tube is turned on, and when the first upper bridge arm switch tube and the second lower bridge arm switch tube are turned on at the same time, the second rectifier switch tube is turned on.

12. A powertrain, characterized in that: The powertrain comprises a DC-DC converter as claimed in any one of claims 1 to 11.

13. A vehicle, characterized in that: The vehicle comprises the DC-DC converter according to any one of claims 1 to 11, or the powertrain according to claim 12.

Images