DCDC control method, device and system and vehicle

Abstract

The invention relates to a DCDC control method, device and system and a vehicle, and the method comprises the steps: obtaining the rated power of at least two DCDCs which are connected in parallel between a high-voltage power supply and a low-voltage load; calculating real-time load rates of the at least two DCDCs according to the real-time power of the low-voltage load; selecting at least one DCDC according to the real-time load rate and the rated power; and controlling the selected DCDC to be connected to a circuit comprising the high-voltage power supply and the low-voltage load so as to adjust the real-time load rate of the selected DCDC to be within a preset load rate range. According to the scheme provided by the invention, one or more combined DCDCs are calculated and called according to the rated power of each DCDC, so that the real-time load rate of each called DCDC is within the preset load rate range, and the maximum utilization efficiency of the DCDC is realized.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a DCDC control method, device, system and vehicle. Background Art

[0002] As the production and sales of new energy vehicles continue to grow, reducing the power consumption of various electrical equipment has become the primary idea to reduce the energy consumption of the entire vehicle and improve the vehicle's endurance. DCDC (i.e. high-voltage direct current converter) plays a bridge role in connecting the power high voltage and 12V low-voltage electrical appliances in new energy vehicles. However, the current low-voltage power consumption of the entire vehicle is small, so the load rate of DCDC is small, and the use efficiency of DCDC is not high, which is not conducive to the endurance of the vehicle.

[0003] In view of the above problems, those skilled in the art have been seeking solutions. Summary of the invention

[0004] The technical problem to be solved by the present application is to provide a DCDC control method, device, system and vehicle in view of the defects of the above-mentioned prior art.

[0005] In order to achieve the above objectives, this application is implemented through the following technical solutions:

[0006] The present application provides a DCDC control method, comprising the following steps:

[0007] Obtaining rated power of at least two DCDCs, wherein the at least two DCDCs are connected in parallel between a high voltage power supply and a low voltage load;

[0008] Calculate the real-time load rate of the at least two DCDCs according to the real-time power of the low-voltage load;

[0009] Selecting at least one of the DCDCs according to the real-time load rate and the rated power;

[0010] The selected DCDC is controlled to be connected to a circuit including the high voltage power supply and the low voltage load, so as to adjust the real-time load rate of the selected DCDC to within a preset load rate range.

[0011] Optionally, the at least two DCDCs have different rated powers.

[0012] Optionally, the method further comprises the following steps:

[0013] Obtaining the required power of the low-voltage load;

[0014] According to the required power and the rated power, at least one first DCDC is selectively controlled to be connected to a circuit including the high voltage power supply and the low voltage load, so that a total output power of at least one first DCDC meets the required power of the low voltage load.

[0015] Optionally, the low-voltage load includes a low-voltage battery;

[0016] The method further comprises:

[0017] Obtaining the charge and discharge efficiency of the low-voltage battery;

[0018] Selecting at least one second DCDC according to the charging and discharging efficiency and the rated power;

[0019] The selected second DCDC is controlled to be connected to a circuit including the high voltage power supply and the low voltage load, so as to adjust the real-time load rate of the selected second DCDC to within a preset load rate range.

[0020] The present application also provides a DCDC control device, comprising: an acquisition module, a calculation module, and an execution module;

[0021] The acquisition module is used to acquire the real-time power of the low-voltage load and the rated power of at least two DCDCs connected in parallel between the high-voltage power supply and the low-voltage load;

[0022] The calculation module is used to calculate the real-time load rate of the at least two DCDCs according to the real-time power;

[0023] The execution module is used to select at least one of the DCDCs according to the real-time load rate and the rated power, and control the selected DCDC to be connected to a circuit including a high-voltage power supply and the low-voltage load to adjust the real-time load rate of the selected DCDC to within a preset load rate range.

[0024] The present application also provides a DCDC control system, comprising: a controller, a high voltage power supply, a DCDC system, and a low voltage load;

[0025] The DCDC system is connected between the high-voltage power supply and the low-voltage load, and the controller is connected to the high-voltage power supply, the DCDC system, and the low-voltage load via a CAN line;

[0026] Wherein, the DCDC system comprises a plurality of DCDC modules connected in parallel;

[0027] The high-voltage power supply is used to output high-voltage electricity;

[0028] The DCDC system is used to convert the high voltage electricity output by the high voltage power supply into low voltage electricity and output the low voltage electricity to the low voltage load;

[0029] The controller is used to obtain the real-time power of the low-voltage load and the rated power of the DCDC module, and calculate the real-time load rate of the DCDC module according to the real-time power, and select at least two of the DCDC modules according to the real-time load rate and the rated power, and control the selected DCDC module to be connected to the circuit including the high-voltage power supply and the low-voltage load to adjust the real-time load rate of the selected DCDC module to within a preset load rate range.

[0030] Optionally, the DCDC module includes a DCDC and a switch;

[0031] The input end of the DCDC is connected to the high voltage power supply, the output end of the DCDC is connected to the first path end of the switch, the second path end of the switch is connected to the low voltage load, and the control end of the switch is connected to the controller;

[0032] The controller is also used to control the switch to close so that the DCDC is connected to the circuit including the high voltage power supply and the low voltage load, or control the switch to open so that the DCDC is not connected to the circuit including the high voltage power supply and the low voltage load.

[0033] Optionally, the DCDC system further includes a first busbar and a second busbar;

[0034] One end of the first busbar is connected to the high voltage power supply, and the other end of the first busbar is connected to the input ends of a plurality of parallel DCDC modules;

[0035] One end of the second busbar is connected to the output ends of a plurality of parallel DCDC modules, and the other end of the second busbar is connected to the low-voltage load;

[0036] The first busbar is used to transmit the high voltage electricity output by the high voltage power supply, and the second busbar is used to transmit the low voltage electricity output by the DCDC module.

[0037] Optionally, the controller is also used to obtain the required power of the low-voltage load, and selectively control at least one first DCDC module to be connected to the circuit including the high-voltage power supply and the low-voltage load according to the required power and the rated power, so that the total output power of at least one of the first DCDC modules meets the required power of the low-voltage load.

[0038] The present application also provides a vehicle, comprising the system as described above.

[0039] The present application provides a DCDC control method, device, system and vehicle, which calculate and call one or more combined DCDCs according to the rated power of each DCDC, so that the real-time load rate of each called DCDC is within a preset load rate range to achieve maximum utilization efficiency of the DCDC.

[0040] In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the following specifically cites preferred embodiments and describes them in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The present application is described in detail below with reference to the accompanying drawings and specific implementation methods.

[0042] Figure 1 is a schematic diagram of the efficiency curve of DCDC provided in one embodiment of the present application;

[0043] Figure 2 is a flow chart of a DCDC control method provided in an embodiment of the present application;

[0044] Figure 3 is a structural schematic diagram of a DCDC control device provided in an embodiment of the present application;

[0045] Figure 4 It is a structural diagram of a DCDC control system provided in one embodiment of the present application. DETAILED DESCRIPTION

[0046] It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0047] DCDC, short for DC-DC converter, also known as high-voltage DC converter, is an electronic device used to convert a DC power supply voltage into another DC power supply voltage of different size or nature. DC-DC converter plays the role of power conversion and power transmission, and is an indispensable component of modern electronic circuits.

[0048] According to current statistics, the maximum low-voltage power consumption of a vehicle is generally 3000W, while the low-voltage load power consumption is about 500W when the user is using the vehicle normally, and the DCDC load rate is about 16.7%. When the vehicle is charged at home using an AC charging station, the low-voltage load power consumption is even lower than 100W, and the DCDC load rate is less than 5%. As a power semiconductor electrical device, DCDC has an efficiency characteristic curve as shown below: Figure 1As shown in the figure, the efficiency of DCDC increases rapidly with the increase of load rate, reaches the highest efficiency value near the load rate of 35%, and then begins to decrease with the increase of load rate. Based on this, the present application proposes a control method of DCDC, which keeps the load rate of DCDC near 35% to reduce the loss of new energy vehicles and increase the cruising range.

[0049] Figure 2 is a flow chart of a DCDC control method provided by an embodiment of the present application, see Figure 2 The present application provides a DCDC control method, comprising the following steps:

[0050] Obtaining rated power of at least two DCDCs, wherein the at least two DCDCs are connected in parallel between a high voltage power supply and a low voltage load;

[0051] Calculate the real-time load rate of at least two DCDCs according to the real-time power of the low-voltage load;

[0052] Select at least one DCDC according to the real-time load rate and rated power;

[0053] The selected DCDC is controlled to be connected to a circuit including a high voltage power supply and a low voltage load, so as to adjust the real-time load rate of the selected DCDC to within a preset load rate range.

[0054] Optionally, at least two DCDCs have different power ratings.

[0055] In this embodiment, at least two DCDCs select multiple DCDCs with lower power, and the multiple DCDCs select different specifications, such as DCDCs with rated power of 300W, 500W, and 800W. A DCDC system is composed of DCDCs of different specifications, and then the DCDC system is used to replace the original vehicle's 2500W to 3000W large DCDC. Various combinations of DCDCs of different specifications are connected to a loop including a high-voltage power supply and a low-voltage load, which can not only cope with loads under different low-voltage powers, but also can be combined together to cope with the high-demand power of special loads of the entire vehicle.

[0056] In one embodiment, at least one candidate DCDC is selected according to the real-time load rate and the rated power, and the candidate DCDC is connected to a loop including a high-voltage power supply and a low-voltage load, so that the high-voltage power output by the high-voltage power supply can be transmitted to the low-voltage load through the candidate DCDC, and at the same time, one or several candidate DCDCs are controlled to be disconnected according to the real-time load rate of the DCDC, so that the real-time load rate of the finally selected DCDC is within a preset load rate range, and the utilization efficiency of the selected DCDC can be maximized.

[0057] Since the load rate corresponding to the maximum efficiency of DCDC is 35%, the preset load rate range in this embodiment is set to [35%-x, 35%+x], and the specific value of x can be set according to the actual situation of the vehicle.

[0058] Optionally, the method further comprises the following steps:

[0059] Obtain the required power of the low-voltage load;

[0060] According to the required power and the rated power, at least one first DCDC is selectively controlled to be connected to a circuit including a high voltage power supply and a low voltage load, so that the total output power of the at least one first DCDC meets the required power of the low voltage load.

[0061] In one embodiment, the power demand of the low-voltage load is obtained, and at least one first DCDC is selected from at least two DCDCs connected in parallel between the high-voltage power supply and the low-voltage load, so that its output power or total output power is greater than or equal to the power demand of the low-voltage load. The first DCDC of this embodiment is used to meet the load demand, and the selected first DCDC is connected to a loop including the high-voltage power supply and the low-voltage load, so that the high-voltage power output by the high-voltage power supply can be transmitted to the low-voltage load through the first DCDC, which can meet the power demand of the car at this time. Similarly, this method can meet the power demand of the car in different scenarios and reduce power loss.

[0062] Optionally, the low voltage load comprises a low voltage battery;

[0063] The method also includes:

[0064] Get the charge and discharge efficiency of low-voltage batteries;

[0065] Selecting at least one second DCDC according to the charging and discharging efficiency and the rated power;

[0066] The selected second DCDC is controlled to be connected to a circuit including a high voltage power supply and a low voltage load, so as to adjust the real-time load rate of the selected second DCDC to within a preset load rate range.

[0067] In some practical situations, the low-voltage battery in the low-voltage load will power the low-voltage electrical appliances. When the power of the low-voltage battery is lower than a preset power threshold, such as 20%, the low-voltage power output by the DCDC is required to charge the low-voltage battery.

[0068] In one embodiment, when the low-voltage load is only a low-voltage battery, the charging and discharging efficiency of the low-voltage battery during the charging and discharging process is calculated, and the real-time load rate of the DCDC is calculated based on the charging and discharging efficiency. At least one candidate second DCDC is selected based on the real-time load rate of the DCDC and the rated power of multiple DCDCs, and the candidate second DCDC is connected to a loop including a high-voltage power supply and a low-voltage load, so that the high-voltage electricity output by the high-voltage power supply can be transmitted to the low-voltage load through the candidate second DCDC. At the same time, one or several candidate second DCDCs are controlled to be disconnected based on the real-time load rate of the DCDC, so that the real-time load rate of the finally selected second DCDC is within a preset load rate range, and the utilization efficiency of the selected DCDC can be maximized.

[0069] In another embodiment, when the low-voltage load is a low-voltage battery and other low-voltage electrical appliances, the charge and discharge efficiency of the low-voltage battery and the real-time power of the low-voltage electrical appliances are calculated, and based on the real-time power and the charge and discharge efficiency and the calculated real-time load rate of the DCDC, at least one candidate second DCDC is selected based on the real-time load rate of the DCDC and the rated power of multiple DCDCs, and the candidate second DCDC is connected to a loop including a high-voltage power supply and a low-voltage load, so that the high-voltage electricity output by the high-voltage power supply can be transmitted to the low-voltage load through the candidate second DCDC, and at the same time, one or several candidate second DCDCs are controlled to be disconnected according to the real-time load rate of the DCDC, so that the real-time load rate of the finally selected second DCDC is within a preset load rate range, and the utilization efficiency of the selected DCDC can be maximized.

[0070] Figure 3 is a schematic diagram of the structure of a DCDC control device provided in an embodiment of the present application, see Figure 3 The present application also provides a DCDC control device, including: an acquisition module, a calculation module, and an execution module.

[0071] The acquisition module is used to acquire the real-time power of the low-voltage load and the rated power of at least two DCDCs connected in parallel between the high-voltage power supply and the low-voltage load.

[0072] The calculation module is used to calculate the real-time load rate of at least two DCDCs according to the real-time power.

[0073] The execution module is used to select at least one DCDC according to the real-time load rate and the rated power, and control the selected DCDC to be connected to a circuit including a high-voltage power supply and a low-voltage load to adjust the real-time load rate of the selected DCDC to within a preset load rate range.

[0074] Figure 4 is a schematic diagram of the structure of a DCDC control system provided by an embodiment of the present application, see Figure 4The present application also provides a DCDC control system, including: a controller, a high voltage power supply, a DCDC system, and a low voltage load. The DCDC system is connected between the high voltage power supply and the low voltage load, and the controller is connected to the high voltage power supply, the DCDC system, and the low voltage load via a CAN line.

[0075] Wherein, the DCDC system includes a plurality of parallel-connected DCDC modules;

[0076] The high voltage power supply is used to output high voltage electricity.

[0077] The DCDC system is used to convert the high voltage electricity output by the high voltage power supply into low voltage electricity and output the low voltage electricity to a low voltage load.

[0078] The controller is used to obtain the real-time power of the low-voltage load and the rated power of the DCDC module, calculate the real-time load rate of the DCDC module according to the real-time power, select at least one DCDC module according to the real-time load rate and the rated power, and control the selected DCDC module to be connected to a circuit including a high-voltage power supply and a low-voltage load to adjust the real-time load rate of the selected DCDC module to within a preset load rate range.

[0079] In one embodiment, the controller directly calculates the load rate of the adaptable DCDC using a software program based on the real-time load rate and the rated power, and then connects the adaptable DCDC to a circuit including a high-voltage power supply and a low-voltage load, so that the high-voltage electricity output by the high-voltage power supply can be transmitted to the low-voltage load through the adaptable DCDC, so that the real-time load rate of the adaptable DCDC is within a preset load rate range, thereby maximizing the utilization efficiency of the selected DCDC.

[0080] Optionally, the DCDC module includes a DCDC and a switch. The input end of the DCDC is connected to a high voltage power supply, the output end of the DCDC is connected to a first path end of the switch, the second path end of the switch is connected to a low voltage load, and the control end of the switch is connected to a controller. The controller is also used to control the switch to close so that the DCDC is connected to a circuit including a high voltage power supply and a low voltage load, or to control the switch to open so that the DCDC is not connected to the circuit including the high voltage power supply and the low voltage load. In one embodiment, the switch can be a relay, and the controller can select the DCDC in the form of a relay switch on and off. The unselected DCDC keeps the corresponding relay switch off without generating any loss.

[0081] Optionally, the DCDC system further comprises a first busbar and a second busbar. One end of the first busbar is connected to a high voltage power supply, and the other end of the first busbar is connected to input ends of a plurality of parallel DCDC modules; one end of the second busbar is connected to output ends of a plurality of parallel DCDC modules, and the other end of the second busbar is connected to a low voltage load.

[0082] The first busbar is used to transmit high voltage electricity output by the high voltage power supply, and the second busbar is used to transmit low voltage electricity output by the DCDC module.

[0083] Optionally, the controller is also used to obtain the required power of the low-voltage load, and selectively connect at least one first DCDC module to a circuit including a high-voltage power supply and a low-voltage load based on the required power and the rated power, so that the total output power of the at least one first DCDC module meets the required power of the low-voltage load.

[0084] In one embodiment, the controller obtains the total power demand of each electrical appliance in the low-voltage load through the CAN line, calculates the total output power of at least one first DCDC in at least two DCDCs, and when the total output power is greater than or equal to the total power demand of the low-voltage load, marks the at least one first DCDC and controls it to be connected between the high-voltage power supply and the low-voltage load, so that the power demand of the car at this time can be met. Similarly, this method can meet the power demand of the car in different scenarios and reduce power loss.

[0085] The present application also provides a vehicle, comprising the system as described above.

[0086] The present application provides a DCDC control method, device, system and vehicle, which calculates and calls one or more combined DCDCs according to the rated power of each DCDC, so that the real-time load rate of each called DCDC is within a preset load rate range, thereby achieving the maximum utilization efficiency of the DCDC.

[0087] Obviously, those skilled in the art can make various changes and modifications to the invention without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these changes and variations. The technical features of the above-described embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0088] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A DCDC control method, characterized in that: The following steps are involved: Obtaining rated power of at least two DCDCs, wherein the at least two DCDCs are connected in parallel between a high voltage power supply and a low voltage load; Calculate the real-time load rate of the at least two DCDCs according to the real-time power of the low-voltage load; Selecting at least one of the DCDCs according to the real-time load rate and the rated power; The selected DCDC is controlled to be connected to a circuit including the high voltage power supply and the low voltage load, so as to adjust the real-time load rate of the selected DCDC to within a preset load rate range.

2. The method according to claim 1, characterized in that The at least two DCDCs have different power ratings.

3. The method according to claim 2, characterized in that The method further comprises the following steps: Obtaining the required power of the low-voltage load; According to the required power and the rated power, at least one first DCDC is selectively controlled to be connected to a circuit including the high voltage power supply and the low voltage load, so that a total output power of at least one first DCDC meets the required power of the low voltage load.

4. The method according to claim 2, characterized in that The low voltage load includes a low voltage battery; The method further comprises: Obtaining the charge and discharge efficiency of the low-voltage battery; Selecting at least one second DCDC according to the charging and discharging efficiency and the rated power; The selected second DCDC is controlled to be connected to a circuit including the high voltage power supply and the low voltage load, so as to adjust the real-time load rate of the selected second DCDC to within a preset load rate range.

5. A DCDC control device, characterized in that: include: Acquisition module, calculation module, execution module; The acquisition module is used to acquire the real-time power of the low-voltage load and the rated power of at least two DCDCs connected in parallel between the high-voltage power supply and the low-voltage load; The calculation module is used to calculate the real-time load rate of the at least two DCDCs according to the real-time power; The execution module is used to select at least one of the DCDCs according to the real-time load rate and the rated power, and control the selected DCDC to be connected to a circuit including a high-voltage power supply and the low-voltage load to adjust the real-time load rate of the selected DCDC to within a preset load rate range.

6. A DCDC control system, characterized in that: include: Controller, high voltage power supply, DCDC system, low voltage load; The DCDC system is connected between the high-voltage power supply and the low-voltage load, and the controller is connected to the high-voltage power supply, the DCDC system, and the low-voltage load via a CAN line; Wherein, the DCDC system comprises a plurality of DCDC modules connected in parallel; The high-voltage power supply is used to output high-voltage electricity; The DCDC system is used to convert the high voltage electricity output by the high voltage power supply into low voltage electricity and output the low voltage electricity to the low voltage load; The controller is used to obtain the real-time power of the low-voltage load and the rated power of the DCDC module, and calculate the real-time load rate of the DCDC module according to the real-time power, and select at least one of the DCDC modules according to the real-time load rate and the rated power, and control the selected DCDC module to be connected to the circuit including the high-voltage power supply and the low-voltage load to adjust the real-time load rate of the selected DCDC module to within a preset load rate range.

7. The system according to claim 6, characterized in that The DCDC module includes a DCDC and a switch; The input end of the DCDC is connected to the high voltage power supply, the output end of the DCDC is connected to the first path end of the switch, the second path end of the switch is connected to the low voltage load, and the control end of the switch is connected to the controller; The controller is also used to control the switch to close so that the DCDC is connected to the circuit including the high voltage power supply and the low voltage load, or control the switch to open so that the DCDC is not connected to the circuit including the high voltage power supply and the low voltage load.

8. The system according to claim 7, characterized in that The DCDC system also includes a first busbar and a second busbar; One end of the first busbar is connected to the high voltage power supply, and the other end of the first busbar is connected to the input ends of a plurality of parallel DCDC modules; One end of the second busbar is connected to the output ends of a plurality of parallel DCDC modules, and the other end of the second busbar is connected to the low-voltage load; The first busbar is used to transmit the high voltage electricity output by the high voltage power supply, and the second busbar is used to transmit the low voltage electricity output by the DCDC module.

9. The system according to claim 7, characterized in that The controller is also used to obtain the required power of the low-voltage load, and selectively control at least one first DCDC module to be connected to the circuit including the high-voltage power supply and the low-voltage load according to the required power and the rated power, so that the total output power of at least one of the first DCDC modules meets the required power of the low-voltage load.

10. A vehicle, characterized in that: Comprising a system as claimed in any one of claims 6-9.

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