OBC + DCDC system of new energy automobile

Abstract

The utility model discloses an OBC + DCDC system of a new energy automobile, and relates to the technical field of new energy charging. The OBC + DCDC system of the new energy automobile comprises a main power board, a control board, a magnetic device board and an assembly structural member, and the main power board is used for power conversion based on OBC + DCDC; the control panel is used for accessing an external input low-voltage power supply, converting the external input low-voltage power supply into multiple paths of voltages with different amplitudes, supplying the voltages to the control panel and the main power board, and receiving and transmitting control information of external control equipment; the magnetic device board is used for separating large-size components on the main power board and performing heat dissipation on the large-size components on the main power board; the assembling structural part is used for assembling the main power board and the control board, and the problems that an existing OBC and DCDC two-in-one scheme is low in integration level, new energy automobiles of different automobile types have different requirements for installation sizes and assembling parts, the OBC and DCDC are low in adaptability, and compatibility of various automobile types is inconvenient are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of new energy charging, in particular to an OBC+DCDC system for a new energy vehicle. Background Art

[0002] On-board charger (OBC) and direct current-direct current converter (DCDC) are important power supply devices on new energy vehicles. OBC is used to charge the high-voltage power battery of new energy vehicles, and DCDC is used to charge the low-voltage battery of new energy vehicles.

[0003] The OBC or DCDC equipped on early new energy vehicles were both separate products. The OBC was installed in one chassis and the DCDC was installed in another chassis. The two were not related to each other. Later, in order to reduce the size and weight of new energy vehicles, reduce the external cables of the whole vehicle, and reduce costs, engineers installed the OBC module and the DCDC module in the same chassis to form an OBC+DCDC two-in-one solution. Compared with the original OBC and DCDC independent solutions, this method does reduce the total volume and total weight, and also reduces the use of connecting cables, reducing costs from the solution. However, due to the low degree of integration, the installation size and assembly location requirements for different models of new energy vehicles are different, and the adaptability of OBC and DCDC is not high, which is not convenient for compatibility with multiple models. Summary of the invention

[0004] In view of the deficiencies in the prior art, the utility model provides an OBC+DCDC system for new energy vehicles, which solves the problems that the existing OBC+DCDC two-in-one solution has low integration, different installation dimensions and assembly location requirements for new energy vehicles of different models, low adaptability of OBC and DCDC, and is not convenient for compatibility with multiple models.

[0005] To achieve the above objectives, the utility model is implemented through the following technical solutions: a new energy vehicle OBC+DCDC system, including a main power board, a control board, a magnetic device board and an assembly structure, wherein: the main power board is used for power conversion based on OBC+DCDC; the control board is used to access an external low-voltage power supply, convert it into multiple voltages of different amplitudes, supply the control board and the main power board, and also for receiving and transmitting control information of external control equipment; the magnetic device board is used to separate large-volume components on the main power board and dissipate heat for the large-volume components on the main power board; the assembly structure is used to assemble the main power board and the control board.

[0006] Furthermore, the main power board includes an on-board charging module and a DC-DC conversion module, wherein: the on-board charging module is used to charge the power battery of the new energy vehicle; the DC-DC conversion module is used to convert DC high voltage into DC low voltage; the output of the on-board charging module is also connected to the input of the DC-DC conversion module.

[0007] Furthermore, the on-board charging module includes a charging boost unit, a charging resonant conversion unit and a charging output filter unit, wherein: the charging boost unit is used to boost the input AC voltage and transmit it to the charging resonant conversion unit; the charging resonant conversion unit is used to perform resonant conversion processing on the boosted AC voltage and transmit it to the charging output filter unit; the charging output filter unit is used to filter the AC voltage output by the charging resonant conversion unit and then charge the power battery of the new energy vehicle, and the charging output filter unit also transmits the filtered AC voltage to the DC-DC conversion module.

[0008] Further, the charging boost unit includes an inductor L1, a MOS tube Q5 and a diode D1, the front end of the inductor L1 is connected to the first pin of the full-bridge rectifier U1, the rear end of the inductor L1 is connected to the D pole of the MOS tube Q5, and the S pole of the MOS tube Q5 is connected to the fourth pin of the full-bridge rectifier U1; the second pin of the full-bridge rectifier U1 is connected to the alternating current AC_L through the protector F1, the third pin of the full-bridge rectifier U1 is connected to the alternating current AC_N, the anode of the diode D1 is connected to the D pole of the MOS tube Q5, the cathode of the diode D1 is connected to one end of the capacitor C1, the other end of the capacitor C1 is grounded, and the two ends of the capacitor C1 are also connected to the charging resonance conversion unit.

[0009] Further, the charging resonance conversion unit includes a MOS tube Q1, a MOS tube Q2, an inductor L3, a transformer T1, and a capacitor C5. The second pin of the MOS tube Q1 is respectively connected to the third pin of the MOS tube Q2 and the front end of the inductor L3, the rear end of the inductor L3 is connected to the second pin of the primary coil of the transformer T1, and the secondary coil of the transformer T1 is connected to the charging output filter unit; the second pin of the MOS tube Q2 is connected to one end of the capacitor C1, the other end of the capacitor C1 is connected to the third pin of the MOS tube Q1 and is grounded, one end of the capacitor C5 is connected to the third pin of the MOS tube Q2, and the other end of the capacitor C5 is connected to the first pin of the primary coil of the transformer T1.

[0010] Furthermore, the charging output filter unit includes a diode D2, a diode D3 and a capacitor C2, the anode of the diode D2 is connected to the fifth pin of the secondary coil of the transformer T1, the cathode of the diode D2 is connected to the cathode of the diode D3 and one end of the capacitor C2 respectively, the anode of the diode D3 is connected to the third pin of the secondary coil of the transformer T1, and the other end of the capacitor C2 is connected to the fourth pin of the secondary coil of the transformer T1. The connection between the cathode of the diode D2 and the capacitor C2 is the DC output end of the charging output filter unit, which is used to charge the power battery of the new energy vehicle and also transmit the filtered AC voltage to the DC-DC conversion module.

[0011] Furthermore, the DC-DC conversion module includes a conversion boost unit, a conversion resonant conversion unit and a conversion output filter unit, wherein: the conversion boost unit is connected to the output of the on-board charging module and boosts the DC power output by the on-board charging module and transmits it to the conversion resonant conversion unit; the conversion resonant conversion unit is used to perform resonant conversion processing on the boosted AC voltage and transmit it to the conversion output filter unit; the conversion output filter unit is used to filter the AC voltage output by the conversion resonant conversion unit and output it.

[0012] Furthermore, the conversion boost unit includes an inductor L2, a MOS tube Q6 and a diode D4, the front end of the inductor L2 is connected to the output of the vehicle charging module, the rear end of the inductor L2 is connected to the second pin of the MOS tube Q6, the third pin of the MOS tube Q6 is grounded, the anode of the diode D4 is connected to the second pin of the MOS tube Q6, the cathode of the diode D4 is connected to one end of the capacitor C3, the other end of the capacitor C3 is grounded, and the two ends of the capacitor C3 are also connected to the conversion resonance conversion unit.

[0013] Further, the conversion resonance conversion unit includes a MOS tube Q3, a MOS tube Q4, an inductor L4, a capacitor C6 and a transformer T2, the second pin of the MOS tube Q3 is respectively connected to the third pin of the MOS tube Q4 and the front end of the inductor L4, the rear end of the inductor L4 is connected to the second pin of the primary coil of the transformer T2, and the secondary coil of the transformer T2 is connected to the charging output filter unit; the second pin of the MOS tube Q4 is connected to one end of the capacitor C3, the other end of the capacitor C3 is connected to the third pin of the MOS tube Q3 and is grounded, one end of the capacitor C6 is connected to the third pin of the MOS tube Q3, and the other end of the capacitor C6 is connected to the first pin of the primary coil of the transformer T2.

[0014] Further, the conversion output filter unit includes a MOS tube Q7, a MOS tube Q8 and a capacitor C4, the third pin of the MOS tube Q7 is connected to the fifth pin of the secondary coil of the transformer T2, the second pin of the MOS tube Q7 is connected to the second pin of the MOS tube Q8 and is grounded, the third pin of the MOS tube Q8 is connected to the third pin of the secondary coil of the transformer T2, one end of the capacitor C4 is grounded, and the other end of the capacitor C4 is connected to the fourth pin of the secondary coil of the transformer T2 as a DC output.

[0015] The utility model has the following beneficial effects:

[0016] (1) The OBC+DCDC system of the new energy vehicle realizes the function of DCDC by directly using the output voltage of OBC as the input voltage of DCDC on the same main power board, and also maximizes the use of the space of the main power board, so that the size of the main power board can be made smaller and the cost is lower.

[0017] (2) The OBC+DCDC system of new energy vehicles separates the large-volume components on the main power board and locks them in an independent heat dissipation container by inverting. The main power board is locked together with the magnetic device board through this heat dissipation container. This separation and locking method maximizes the use of the space structure around the main power board and solves the contradiction between large-volume components and small-size products.

[0018] (3) In the OBC+DCDC system of new energy vehicles, the OBC part and the DCDC part are deeply integrated on the main power board and the control board, and the common circuits of the two are integrated together to achieve the maximum degree of two-in-one.

[0019] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the structure of the OBC+DCDC system of the new energy vehicle of this utility model.

[0021] Figure 2 This is a schematic diagram of the circuit structure of the on-board charging module of the OBC+DCDC system of the utility model new energy vehicle.

[0022] Figure 3 This is a schematic diagram of the circuit structure of the DC-DC conversion module of the OBC+DCDC system of the utility model new energy vehicle.

[0023] In the figure, 1. Main power board; 2. Control board; 3. Magnetic device board; 4. Assembly structure. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0025] In the description of the present invention, it should be understood that terms such as "opening", "upper", "lower", "thickness", "top", "middle", "length", "inside", "all around" and the like indicating orientation or positional relationship are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0026] This solution is about a deep two-in-one solution that further integrates OBC+DCDC. This patented solution uses the DC high-voltage output of OBC directly as the DC high-voltage input of DCDC, and directly puts the power parts of OBC and DCDC on the same power board. OBC and DCDC share a control board, maximizing the integration of the two originally independent parts, further reducing the volume and weight of the OBC+DCDC two-in-one, and reducing the high-voltage and low-voltage cables used to connect the two, thereby reducing the material cost from the solution. Moreover, this small-volume two-in-one module solution can be adapted to a variety of different chassis, meeting the installation and layout requirements of different models, and can be applied to a variety of new energy vehicle models. At the same time, because the materials used are reduced, the reliability of the OBC+DCDC two-in-one is also improved, and the failure rate is reduced.

[0027] See also Figure 1 The embodiment of the utility model provides a technical solution: an OBC+DCDC system for new energy vehicles, comprising a main power board 1, a control board 2, a magnetic device board 3 and an assembly structure 4, wherein: the main power board 1 is used for power conversion based on OBC+DCDC; the control board 2 is used to access an external low-voltage power supply, convert it into multiple voltages of different amplitudes, supply the control board 2 and the main power board 1, and also for receiving and transmitting control information of an external control device; the magnetic device board 3 is used to separate large-volume components on the main power board 1 and dissipate heat for the large-volume components on the main power board 1; the assembly structure 4 is used to assemble the main power board 1 and the control board 2.

[0028] The main power board 1 is the part of the whole solution that realizes power conversion. The main power board 1 is mainly composed of two parts, one is the OBC part, and the other is the DCDC part. The main power board 1 realizes the conversion function of high voltage and large current signals, and the control board 2 plays the function of low voltage and small signal conversion. To realize the function of the main power circuit, it is inseparable from the power supply of the low-voltage power supply and the sampling feedback results of the key voltage and current signals. The control board 2 integrates the low-voltage power supply circuit, the single-chip circuit, the communication circuit, the voltage and current signal acquisition circuit and other signal sampling circuits.

[0029] Control board 2 is the core of the whole solution. The low-voltage power supply circuit on control board 2 converts a single external input low-voltage power supply into multiple voltages of different amplitudes, which are supplied to the circuits and chips on control board 2 and main power board 1. The single-chip microcomputer on control board 2 monitors the key signals of main power board 1 through the signal transmission of external auxiliary circuits, the sampling of voltage and current sampling circuits and other signal sampling circuits, and makes corresponding control methods to ensure the stability of main power conversion. The communication circuit on control board 2 is used to receive and transmit interactive information between external devices and single-chip microcomputers, receive control instructions from external devices for OBC+DCDC two-in-one modules, and upload voltage, current, temperature and other information of the two-in-one module collected by the single-chip microcomputer, so as to realize the intercommunication between the module and external control devices.

[0030] In this solution, the two originally independent parts, OBC and DCDC, share a control board 2. This control board 2 integrates the common circuits of OBC and DCDC, thereby improving the integration of the OBC+DCDC two-in-one module.

[0031] The large-volume components of the magnetic device board 3 are separated separately, and locked in an independent heat dissipation container by means of inverted buckling. The main power board 1 is locked together with the magnetic device board 3 through this heat dissipation container. This separation and locking method makes the best use of the space structure around the main power board 1, and also solves the contradiction between large-volume components and small-size products. The PFC inductor L1, LLC resonant inductor L3 and LLC resonant transformer T1 of the OBC part on the magnetic device board 3 are all devices with large heat generation and large volume in this solution. A separate magnetic device board 3 is set up to assemble these three magnetic devices with large heat generation together, and locked on the independent heat dissipation container of the OBC by inverted buckling. Then, by filling the heat dissipation container with thermal conductive glue, most of the heat generated by the OBC+DCDC two-in-one module can be conducted away, achieving a better heat dissipation effect of the two-in-one module.

[0032] In this solution, the volume and weight of the OBC+DCDC two-in-one module are reduced by adding a separate magnetic device plate 3 and a unique process of locking the magnetic device plate 3 upside down, while keeping the power of OBC and DCDC unchanged. The entire two-in-one module can be installed in different vehicle models through the heat dissipation aluminum substrate, which also improves the adaptability and compatibility of the two-in-one module.

[0033] In addition to the three key boards of the main power board 1, the control board 2 and the magnetic device board 3, it also includes a structural part for connecting and assembling these three boards, that is, the assembly structure 4. The structural part mainly includes the bottom aluminum substrate, the OBC magnetic device heat dissipation container and three EMC shielding covers. During assembly, first lock the main power board 1, the control board 2 and the magnetic device board 3 in the corresponding aluminum structural parts with screws according to the assembly sequence. After the assembly is completed, the heat dissipation effect of the OBC+DCDC two-in-one module is achieved by pouring thermal conductive glue into the OBC magnetic device heat dissipation container and the bottom aluminum substrate. The overall manufacturing process is simple and controllable, and the producibility and maintainability of the OBC+DCDC two-in-one module are realized.

[0034] Specifically, the main power board 1 includes an on-board charging module and a DC-DC conversion module, wherein: the on-board charging module is used to charge the power battery of the new energy vehicle; the DC-DC conversion module is used to convert DC high voltage into DC low voltage; the output of the on-board charging module is also connected to the input of the DC-DC conversion module.

[0035] In this implementation scheme, the main power board is the part of the whole scheme that realizes power conversion. The main power board is mainly composed of two parts, one is the OBC part, that is, the on-board charging module, and the other is the DCDC part, that is, the DC-DC conversion module.

[0036] The OBC part takes 220V AC voltage as input, increases the voltage to 430V DC, improves the power factor of the input circuit, and converts the DC 430V into an adjustable DC voltage with an adjustable range of 250V-450V. This voltage is the output voltage of the OBC. By adjusting this voltage, the charging effect of the power battery of new energy vehicles can be achieved.

[0037] The output voltage network of the OBC part is also the input voltage network of the DCDC part. On the same main power board, the output voltage of the OBC is directly used as the input voltage of the DCDC to realize the function of DCDC, and also maximize the use of the space of the main power board, so that the size of the main power board can be made smaller and the cost is lower. In the DCDC part, the DC voltage output by the OBC is converted into DC 460V after boosting. Through the control method of soft switching, the bus voltage of DCDC 460V is converted into AC voltage, and then filtered and absorbed to output DC low voltage 14V, thereby realizing the DC-DC function of converting DC high voltage into DC low voltage.

[0038] Specifically, Figure 2 As shown, the on-board charging module includes a charging boost unit, a charging resonant conversion unit and a charging output filter unit, wherein: the charging boost unit is used to boost the input AC voltage and transmit it to the charging resonant conversion unit; the charging resonant conversion unit is used to perform resonant conversion processing on the boosted AC voltage and transmit it to the charging output filter unit; the charging output filter unit is used to filter the AC voltage output by the charging resonant conversion unit and then charge the power battery of the new energy vehicle, and the charging output filter unit also transmits the filtered AC voltage to the DC-DC conversion module.

[0039] In this implementation, the main power board takes 220V AC voltage as input, rectifies the AC voltage into a positive waveform, and increases the voltage to 430V DC through the charging boost unit. The charging boost unit is a boost circuit, which is supplied to the next level circuit, that is, the charging resonant conversion unit. The charging resonant conversion unit performs resonant conversion processing and then inputs the charging output filter unit to convert the DC 430V into an adjustable DC voltage in the adjustable range of 250V-450V. This voltage is the output voltage of the OBC. By adjusting this voltage, the charging effect of the power battery of the new energy vehicle can be achieved.

[0040] Specifically, the charging boost unit includes an inductor L1, a MOS tube Q5 and a diode D1. The front end of the inductor L1 is connected to the first pin of the full-bridge rectifier U1, the rear end of the inductor L1 is connected to the D pole of the MOS tube Q5, and the S pole of the MOS tube Q5 is connected to the fourth pin of the full-bridge rectifier U1; the second pin of the full-bridge rectifier U1 is connected to the alternating current AC_L through the protector F1, the third pin of the full-bridge rectifier U1 is connected to the alternating current AC_N, the anode of the diode D1 is connected to the D pole of the MOS tube Q5, the cathode of the diode D1 is connected to one end of the capacitor C1, the other end of the capacitor C1 is grounded, and the two ends of the capacitor C1 are also connected to the charging resonance conversion unit.

[0041] In this implementation scheme, the main power board takes 220V AC voltage as input, first rectifies the AC voltage into a positive waveform through the U1 full-bridge rectifier of the OBC part, and then increases the voltage to 430V DC through the boost circuit composed of inductor L1, MOS tube Q5 and diode D1. Capacitor C1 is the bus capacitor of the boost circuit, which is used to filter and stabilize the DC voltage waveform and supply it to the next level circuit, so that the input voltage waveform of the next level circuit is clean and stable. The full-bridge rectifier U1, inductor L1, MOS tube Q5, diode D1, and capacitor C1 form a PFC (Power Factor Correction) circuit in principle. The advantage of the PFC circuit is that it can make the input voltage and input current phase the same, thereby improving the power factor of the input circuit.

[0042] Specifically, the charging resonance conversion unit includes a MOS tube Q1, a MOS tube Q2, an inductor L3, a transformer T1, and a capacitor C5. The second pin of the MOS tube Q1 is respectively connected to the third pin of the MOS tube Q2 and the front end of the inductor L3, the rear end of the inductor L3 is connected to the second pin of the primary coil of the transformer T1, and the secondary coil of the transformer T1 is connected to the charging output filter unit; the second pin of the MOS tube Q2 is connected to one end of the capacitor C1, the other end of the capacitor C1 is connected to the third pin of the MOS tube Q1 and is grounded, one end of the capacitor C5 is connected to the third pin of the MOS tube Q2, and the other end of the capacitor C5 is connected to the first pin of the primary coil of the transformer T1.

[0043] The charging output filter unit includes a diode D2, a diode D3 and a capacitor C2. The anode of the diode D2 is connected to the fifth pin of the secondary coil of the transformer T1, the cathode of the diode D2 is connected to the cathode of the diode D3 and one end of the capacitor C2 respectively, the anode of the diode D3 is connected to the third pin of the secondary coil of the transformer T1, and the other end of the capacitor C2 is connected to the fourth pin of the secondary coil of the transformer T1. The connection between the cathode of the diode D2 and the capacitor C2 is the DC output end of the charging output filter unit, which is used to charge the power battery of the new energy vehicle and also transmit the filtered AC voltage to the DC-DC conversion module.

[0044] In this implementation scheme, MOS tube Q1, MOS tube Q2, inductor L3, transformer T1, and capacitor C5 form an LLC circuit (also called a resonant conversion circuit), and diode D2, diode D3, and capacitor C2 form an output filter circuit of the LLC circuit. The combination of LLC + output filter circuit converts the DC 430V output by the first-stage PFC circuit into an adjustable DC voltage in the adjustable range of 250V-450V. This voltage is the output voltage of the OBC. By adjusting this voltage, the charging effect of the power battery of the new energy vehicle can be achieved.

[0045] Specifically, Figure 3 As shown, the DC-DC conversion module includes a conversion boost unit, a conversion resonant conversion unit and a conversion output filter unit, wherein: the conversion boost unit is connected to the output of the on-board charging module and boosts the DC power output by the on-board charging module and transmits it to the conversion resonant conversion unit; the conversion resonant conversion unit is used to perform resonant conversion processing on the boosted AC voltage and then transmit it to the conversion output filter unit; the conversion output filter unit is used to filter the AC voltage output by the conversion resonant conversion unit and then output it.

[0046] In this implementation, the output voltage network of the OBC part is also the input voltage network of the DCDC part. On the same main power board, the output voltage of the OBC is directly used as the input voltage of the DCDC to realize the function of DCDC, and the space of the main power board is utilized to the maximum extent, so that the size of the main power board can be made smaller and the cost is lower.

[0047] The conversion and boost unit converts the DC voltage output by the OBC into DC 460V after boosting, and supplies it to the next level circuit. Through the control method of soft switch, the bus voltage 460V of DCDC is converted into AC voltage. Then, after the filtering and absorption function of the conversion output filter unit, a DC low voltage 14V is output, thus realizing the DC-DC function of converting DC high voltage into DC low voltage.

[0048] Specifically, the conversion boost unit includes an inductor L2, a MOS tube Q6 and a diode D4. The front end of the inductor L2 is connected to the output of the vehicle charging module, the rear end of the inductor L2 is connected to the second pin of the MOS tube Q6, the third pin of the MOS tube Q6 is grounded, the anode of the diode D4 is connected to the second pin of the MOS tube Q6, the cathode of the diode D4 is connected to one end of the capacitor C3, the other end of the capacitor C3 is grounded, and the two ends of the capacitor C3 are also connected to the conversion resonance conversion unit.

[0049] In this embodiment, in the DCDC part, the inductor L2, MOS tube Q6 and diode D4 also form a boost circuit, which converts the DC voltage output by the OBC into a DC 460V after boosting, and supplies it to the LLC circuit of the next level. C3 is the bus capacitor of the DCDC, which is also used to filter and stabilize the DC voltage waveform.

[0050] Specifically, the conversion resonance conversion unit includes a MOS tube Q3, a MOS tube Q4, an inductor L4, a capacitor C6 and a transformer T2. The second pin of the MOS tube Q3 is respectively connected to the third pin of the MOS tube Q4 and the front end of the inductor L4, the rear end of the inductor L4 is connected to the second pin of the primary coil of the transformer T2, and the secondary coil of the transformer T2 is connected to the charging output filter unit; the second pin of the MOS tube Q4 is connected to one end of the capacitor C3, the other end of the capacitor C3 is connected to the third pin of the MOS tube Q3 and is grounded, one end of the capacitor C6 is connected to the third pin of the MOS tube Q3, and the other end of the capacitor C6 is connected to the first pin of the primary coil of the transformer T2.

[0051] The conversion output filter unit includes a MOS transistor Q7, a MOS transistor Q8 and a capacitor C4. The third pin of the MOS transistor Q7 is connected to the fifth pin of the secondary coil of the transformer T2. The second pin of the MOS transistor Q7 is connected to the second pin of the MOS transistor Q8 and is grounded. The third pin of the MOS transistor Q8 is connected to the third pin of the secondary coil of the transformer T2. One end of the capacitor C4 is grounded, and the other end of the capacitor C4 is connected to the fourth pin of the secondary coil of the transformer T2 as a DC output.

[0052] In this embodiment, MOS transistor Q3, MOS transistor Q4, inductor L4, capacitor C6 and transformer T2 form the LLC circuit of DCDC, and convert the bus voltage 460V of DCDC into AC voltage through soft switch control. Then, through the filtering and absorption effect of MOS transistors Q7, Q8 and capacitor C4, a DC low voltage 14V is output, thereby realizing the DC-DC effect of converting DC high voltage into DC low voltage.

[0053] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0054] The preferred embodiments of the utility model disclosed above are only used to help explain the utility model. The preferred embodiments do not describe all the details in detail, nor do they limit the utility model to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the utility model, so that technicians in the relevant technical field can well understand and use the utility model. The utility model is limited only by the claims and their full scope and equivalents.

Claims

1. A new energy vehicle OBC+DCDC system, characterized in that: It comprises a main power board (1), a control board (2), a magnetic device board (3) and an assembly structure (4), wherein: The main power board (1) is used for performing power conversion based on OBC+DCDC; The control board (2) is used to receive an external low-voltage power supply, convert it into multiple voltages of different amplitudes, supply them to the control board (2) and the main power board (1), and also to receive and transmit control information of an external control device; The magnetic device board (3) is used to separate large-volume components on the main power board (1) and to dissipate heat from the large-volume components on the main power board (1); The assembly structure (4) is used to assemble the main power board (1) and the control board (2).

2. The OBC+DCDC system for new energy vehicles according to claim 1, characterized in that: The main power board (1) comprises an on-board charging module and a DC-DC conversion module, wherein: The on-board charging module is used to charge the power battery of the new energy vehicle; The DC-DC conversion module is used to convert DC high voltage into DC low voltage; The output of the vehicle-mounted charging module is also connected to the input of the DC-DC conversion module.

3. The OBC+DCDC system for new energy vehicles according to claim 2, characterized in that: The vehicle-mounted charging module includes a charging boost unit, a charging resonance conversion unit and a charging output filter unit, wherein: The charging boost unit is used to boost the input AC voltage and transmit it to the charging resonance conversion unit; The charging resonance conversion unit is used to post-transmit the boosted AC voltage to the charging output filter unit; The charging output filter unit is used to filter the AC voltage output by the charging resonance conversion unit to charge the power battery of the new energy vehicle. The charging output filter unit also transmits the filtered AC voltage to the DC-DC conversion module.

4. The OBC+DCDC system for new energy vehicles according to claim 3 is characterized in that: The charging boost unit includes an inductor L1, a MOS tube Q5 and a diode D1, wherein the front end of the inductor L1 is connected to the first pin of the full-bridge rectifier tube U1, the rear end of the inductor L1 is connected to the D pole of the MOS tube Q5, and the S pole of the MOS tube Q5 is connected to the fourth pin of the full-bridge rectifier tube U1; The second pin of the full-bridge rectifier U1 is connected to the alternating current AC_L through the protector F1, the third pin of the full-bridge rectifier U1 is connected to the alternating current AC_N, the anode of the diode D1 is connected to the D pole of the MOS tube Q5, the cathode of the diode D1 is connected to one end of the capacitor C1, the other end of the capacitor C1 is grounded, and the two ends of the capacitor C1 are also connected to the charging resonance conversion unit.

5. The OBC+DCDC system for new energy vehicles according to claim 4, characterized in that: The charging resonance conversion unit includes a MOS tube Q1, a MOS tube Q2, an inductor L3, a transformer T1, and a capacitor C5. The second pin of the MOS tube Q1 is connected to the third pin of the MOS tube Q2 and the front end of the inductor L3 respectively. The rear end of the inductor L3 is connected to the second pin of the primary coil of the transformer T1. The secondary coil of the transformer T1 is connected to the charging output filter unit. The second pin of the MOS tube Q2 is connected to one end of the capacitor C1, the other end of the capacitor C1 is connected to the third pin of the MOS tube Q1 and is grounded, one end of the capacitor C5 is connected to the third pin of the MOS tube Q2, and the other end of the capacitor C5 is connected to the first pin of the primary coil of the transformer T1.

6. The OBC+DCDC system for new energy vehicles according to claim 5, characterized in that: The charging output filter unit includes a diode D2, a diode D3 and a capacitor C2. The anode of the diode D2 is connected to the fifth pin of the secondary coil of the transformer T1, the cathode of the diode D2 is connected to the cathode of the diode D3 and one end of the capacitor C2 respectively, the anode of the diode D3 is connected to the third pin of the secondary coil of the transformer T1, and the other end of the capacitor C2 is connected to the fourth pin of the secondary coil of the transformer T1. The connection between the cathode of the diode D2 and the capacitor C2 is the DC output end of the charging output filter unit, which is used to charge the power battery of the new energy vehicle and also transmit the filtered AC voltage to the DC-DC conversion module.

7. The OBC+DCDC system for new energy vehicles according to claim 2, characterized in that: The DC-DC conversion module includes a conversion boost unit, a conversion resonant conversion unit and a conversion output filter unit, wherein: The conversion and boosting unit is connected to the output of the on-board charging module and boosts the DC power output by the on-board charging module and transmits it to the conversion resonance conversion unit; The conversion resonance conversion unit is used to post-transmit the boosted AC voltage to the conversion output filter unit; The conversion output filtering unit is used for filtering the AC voltage output by the conversion resonance conversion unit and then outputting it.

8. The OBC+DCDC system for new energy vehicles according to claim 7, characterized in that: The conversion boost unit includes an inductor L2, a MOS tube Q6 and a diode D4. The front end of the inductor L2 is connected to the output of the vehicle charging module, the rear end of the inductor L2 is connected to the second pin of the MOS tube Q6, the third pin of the MOS tube Q6 is grounded, the anode of the diode D4 is connected to the second pin of the MOS tube Q6, the cathode of the diode D4 is connected to one end of the capacitor C3, the other end of the capacitor C3 is grounded, and the two ends of the capacitor C3 are also connected to the conversion resonance conversion unit.

9. The OBC+DCDC system for new energy vehicles according to claim 8, characterized in that: The conversion resonance conversion unit includes a MOS tube Q3, a MOS tube Q4, an inductor L4, a capacitor C6 and a transformer T2, the second pin of the MOS tube Q3 is respectively connected to the third pin of the MOS tube Q4 and the front end of the inductor L4, the rear end of the inductor L4 is connected to the second pin of the primary coil of the transformer T2, and the secondary coil of the transformer T2 is connected to the charging output filter unit; The second pin of the MOS tube Q4 is connected to one end of the capacitor C3, the other end of the capacitor C3 is connected to the third pin of the MOS tube Q3 and is grounded, one end of the capacitor C6 is connected to the third pin of the MOS tube Q3, and the other end of the capacitor C6 is connected to the first pin of the primary coil of the transformer T2.

10. The OBC+DCDC system for new energy vehicles according to claim 9, characterized in that: The conversion output filter unit includes a MOS transistor Q7, a MOS transistor Q8 and a capacitor C4, the third pin of the MOS transistor Q7 is connected to the fifth pin of the secondary coil of the transformer T2, the second pin of the MOS transistor Q7 is connected to the second pin of the MOS transistor Q8 and is grounded, the third pin of the MOS transistor Q8 is connected to the third pin of the secondary coil of the transformer T2, one end of the capacitor C4 is grounded, and the other end of the capacitor C4 is connected to the fourth pin of the secondary coil of the transformer T2 as a DC output.

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