Low-speed vehicle lithium battery power supply system

Abstract

The application discloses a low-speed vehicle lithium battery power supply system, which comprises an energy storage module, a control strategy module and an execution module, the output end of the energy storage module is electrically connected with the input end of the control strategy module, the output end of the control strategy module is electrically connected with the input end of the execution module, and the output end of the execution module is electrically connected with the input end of the energy storage module; the energy storage module comprises a first lithium battery, a second lithium battery, a super capacitor and a direct-current bus; the first lithium battery, the second lithium battery and the super capacitor are electrically connected with the control strategy module respectively; and the first lithium battery, the second lithium battery and the super capacitor are electrically connected with the execution module respectively. The low-speed vehicle lithium battery power supply system of the application can monitor the voltage and current parameters of the energy storage module in real time through the control strategy module, calculate the output expected value to the execution module, and control the output voltage and output current of the energy storage module according to the expected value of the current and voltage.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power supply systems, in particular to a low-speed vehicle lithium battery power supply system. BACKGROUND

[0002] Low speed vehicle (LSV) refers to a vehicle designed for low-speed driving, usually used in campus, community, golf course and other environments, and its maximum speed is generally below 40 km / h. Low-speed vehicle lithium battery power supply system refers to an electric power system used to drive low-speed vehicles, which includes lithium batteries, electric motors, controllers and related electronic components and electrical systems.

[0003] However, the existing optimization control strategy of low-speed vehicle lithium battery power supply system is difficult to meet the optimization control of multi-source coupled power supply system, thereby reducing the performance of the power supply system. SUMMARY

[0004] Therefore, it is necessary to provide a low-speed vehicle lithium battery power supply system to solve the technical problem that the existing optimization control strategy of low-speed vehicle lithium battery power supply system is difficult to meet the optimization control of multi-source coupled system.

[0005] A low-speed vehicle lithium battery power supply system includes an energy storage module, a control strategy module and an execution module, wherein the output end of the energy storage module is electrically connected to the load, and the output end of the energy storage module is electrically connected to the input end of the control strategy module; the output end of the control strategy module is electrically connected to the input end of the execution module; and the output end of the execution module is electrically connected to the input end of the energy storage module.

[0006] The energy storage module includes a first lithium battery, a second lithium battery, a super capacitor and a DC bus, the output end of the first lithium battery, the output end of the second lithium battery and the output end of the super capacitor are respectively electrically connected to the input end of the DC bus; the output end of the first lithium battery, the output end of the second lithium battery and the output end of the super capacitor are respectively electrically connected to the input end of the control strategy module; and the input end of the first lithium battery, the input end of the second lithium battery and the input end of the super capacitor are respectively electrically connected to the output end of the execution module.

[0007] In one embodiment, the first lithium battery is further provided with a first DC / DC converter, and the first lithium battery is connected in series with the first DC / DC converter.

[0008] In one embodiment, the first DC / DC converter is a bidirectional DC / DC converter.

[0009] In one embodiment, the second lithium battery is further provided with a second DC / DC converter, and the second lithium battery is connected in series with the second DC / DC converter.

[0010] In one of the embodiments, the second DC / DC converter is configured as a bidirectional DC / DC converter.

[0011] In one of the embodiments, the super capacitor is further provided with a third DC / DC converter, and the super capacitor is connected in series with the third DC / DC converter.

[0012] In one of the embodiments, the third DC / DC converter is configured as a bidirectional DC / DC converter.

[0013] In one of the embodiments, the first lithium battery, the second lithium battery and the super capacitor are connected in parallel to the input end of the DC bus through the first DC / DC converter, the second DC / DC converter and the third DC / DC converter respectively.

[0014] In one of the embodiments, the energy storage module further comprises an inverter, the input end of the inverter is electrically connected to the output end of the DC bus, and the output end of the inverter is electrically connected to the load.

[0015] In one of the embodiments, the control strategy module comprises an event-driven mechanism unit and a double-layer structure MPC controller, the input end of the event-driven mechanism unit is electrically connected to the output end of the first lithium battery, the output end of the second lithium battery and the output end of the super capacitor respectively, the output end of the event-driven mechanism unit is electrically connected to the input end of the double-layer structure MPC controller, and the output end of the double-layer structure MPC controller is electrically connected to the input end of the execution module.

[0016] In one of the embodiments, the double-layer structure MPC controller comprises a steady-state target calculation layer and a dynamic optimization control layer.

[0017] In summary, the low-speed vehicle lithium battery power supply system disclosed by the application stores electric energy through the energy storage module and can supply power to the load. In the process, the control strategy module monitors the voltage and current parameters of the energy storage module in real time, calculates the output expected value to the execution module, and the execution module controls the output voltage and output current of the energy storage module according to the expected value of the current and voltage, so as to realize the automatic control of the low-speed lithium battery power supply system. The control strategy module includes an event-driven mechanism unit and a double-layer structure MPC controller. The voltage values and current values collected by the first lithium battery, the second lithium battery and the super capacitor are transmitted to the control strategy module, and the event-driven mechanism unit updates the current values and voltage values of the three power supplies in different working conditions, and then transmits the updated current values and voltage values to the double-layer structure MPC controller. The optimal set point is calculated through the steady-state target calculation layer, and the set point is tracked in real time through the dynamic optimization control layer, so as to obtain the expected current values of the three power supplies and transmit them to the PI controller. The switching duty ratio of the three power supply series DC / DC converter is obtained by solving the PI controller, and then the three groups of duty ratios are output to the first DC / DC converter, the second DC / DC converter and the third DC / DC converter to realize the switching action, so that the low-speed vehicle lithium battery power supply system of the application realizes fast and accurate closed-loop control. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the low-speed vehicle lithium battery power supply system in an embodiment. DETAILED DESCRIPTION

[0019] In order to make the above-mentioned purposes, features and advantages of the application more obvious and easy to understand, the specific embodiments of the application will be described in detail below. In the following description, many specific details are set forth in order to provide a thorough understanding of the application. However, the application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the scope of the application, so the application is not limited to the specific embodiments disclosed below.

[0020] In the description of the application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

[0021] Furthermore, the terms "first", "second", and the like, do not denote any order, quantity, combination, or importance, but rather are used to nomenclature different components. Thus, such terms are used herein, for purposes of description and are in no way limiting. The terms "plurality" and "a plurality" contain the meaning of "multiple" or "two or more" unless expressly specified otherwise by the context.

[0022] In the present application, unless otherwise expressly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be interpreted broadly, for example, can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through intermediate media, can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise expressly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0023] In the present application, unless otherwise expressly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through intermediate media. Moreover, the first feature "above", "over" and "on" the second feature can be directly above or obliquely above the first feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be directly below or obliquely below the first feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0024] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there can be a middle element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or there can be a middle element. The terms "vertical", "horizontal", "up", "down", "left", "right", and similar expressions used herein are for illustrative purposes only and are not the only implementation.

[0025] Please refer to Figure 1The application discloses a low-speed vehicle lithium battery power supply system, which comprises an energy storage module 1, a control strategy module 2 and an execution module 3, wherein the output end of the energy storage module 1 is electrically connected with a load, and the output end of the energy storage module 1 is electrically connected with the input end of the control strategy module 2; the output end of the control strategy module 2 is electrically connected with the input end of the execution module 3; and the output end of the execution module 3 is electrically connected with the input end of the energy storage module 1. In actual application, the energy storage module 1 stores electric energy and can supply power to the load, in the process, the control strategy module 2 monitors the voltage and current parameters of the energy storage module 1 in real time, calculates an output expected value to the execution module 3, and the execution module 3 controls the output voltage and output current of the energy storage module 1 according to the expected value of the current and voltage, so as to realize automatic control of the low-speed vehicle lithium battery power supply system.

[0026] Further, the energy storage module 1 comprises a first lithium battery 11, a second lithium battery 12, a super capacitor 13 and a DC bus 14, the output end of the first lithium battery 11, the output end of the second lithium battery 12 and the output end of the super capacitor 13 are respectively electrically connected with the input end of the DC bus 14; the output end of the first lithium battery 11, the output end of the second lithium battery 12 and the output end of the super capacitor 13 are respectively further electrically connected with the input end of the control strategy module 2; and the input end of the first lithium battery 11, the input end of the second lithium battery 12 and the input end of the super capacitor 13 are respectively electrically connected with the output end of the execution module 3. The first lithium battery 11, the second lithium battery 12 and the super capacitor 13 are respectively electrically connected with the load through the DC bus 14, so as to supply power to the load, and the energy coupling between the first lithium battery 11, the second lithium battery 12 and the super capacitor 13 is realized, the first lithium battery 11 is used for providing the average power required by the vehicle, the second lithium battery 12 is used for providing insufficient power and absorbing excess power, and the super capacitor 13 is used for recovering and outputting transient large current, so as to reduce the power requirement of the first lithium battery 11 and the second lithium battery 12, and prolong the service life thereof.

[0027] Further, the first lithium battery 11 is further provided with a first DC / DC converter 111, and the first lithium battery 11 is connected with the first DC / DC converter 111 in series. Specifically, in the embodiment, the first DC / DC converter 111 is arranged as a bidirectional DC / DC converter.

[0028] Further, the second lithium battery 12 is further provided with a second DC / DC converter 121, and the second lithium battery 12 is connected with the second DC / DC converter 121 in series. Specifically, in the embodiment, the second DC / DC converter 121 is arranged as a bidirectional DC / DC converter.

[0029] Furthermore, the supercapacitor 13 is also equipped with a third DC / DC converter 131, which is connected in series. Specifically, in this embodiment, the third DC / DC converter 131 is configured as a bidirectional DC / DC converter.

[0030] Specifically, the first lithium battery 11, the second lithium battery 12, and the supercapacitor 13 are connected in parallel to the input terminal of the DC bus 14 through the first DC / DC converter 111, the second DC / DC converter 121, and the third DC / DC converter 131, respectively. This makes the output voltage of the low-speed vehicle lithium battery power system more stable and easier to regulate and control the voltage safely. It also enables the low-speed vehicle lithium battery power system to have higher main controllability and a wider voltage adjustable range.

[0031] Furthermore, the energy storage module 1 also includes an inverter 14, the input terminal of which is electrically connected to the output terminal of the DC bus 14, and the output terminal of the inverter 14 is electrically connected to the load, thereby enabling the low-speed vehicle lithium battery power system to output stable power to the load.

[0032] Furthermore, the control strategy module 2 includes an event-driven mechanism unit 21 and a two-layer MPC controller 22. The input terminals of the event-driven mechanism unit 21 are electrically connected to the output terminals of the first lithium battery 11, the second lithium battery 12, and the supercapacitor 13, respectively, thereby collecting current and voltage information from the first lithium battery 11, the second lithium battery 12, and the supercapacitor 13. The output terminal of the event-driven mechanism unit 21 is electrically connected to the input terminal of the two-layer MPC controller 22, so as to output the corresponding current and voltage values ​​obtained after event-driven mechanism processing to the two-layer MPC controller 22. The output terminal of the two-layer MPC controller 22 is electrically connected to the input terminal of the execution module 3, so as to output the corresponding desired current and voltage values ​​to the execution module 3 for the first lithium battery 11, the second lithium battery 12, and the supercapacitor 13, respectively. In practical applications, the event-driven mechanism unit 21 can solve the problem of the dynamic response characteristics of the first lithium battery 11, the second lithium battery 12, and the supercapacitor 13 under external stimulation, so that the first lithium battery 11, the second lithium battery 12, and the supercapacitor 13 with scale response can all respond quickly.

[0033] Specifically, the two-layer MPC controller 22 includes a steady-state target calculation layer 221 and a dynamic optimization control layer 222. The two-layer MPC controller 22 performs power supply scheduling under a hierarchical decision-making mechanism, enabling the fast-response system to achieve high-precision real-time optimization control under multi-energy coupling constraints. That is, in each control cycle, it uses the system's mathematical model to predict the power system's behavior over a future period, and based on these predictions, generates and outputs the optimal control signal to the execution module 3.

[0034] In practical applications, the voltage and current values ​​collected by the first lithium battery 11, the second lithium battery 12, and the supercapacitor 13 are transmitted to the control strategy module 2. The event-driven mechanism unit 21 updates the current and voltage values ​​of the three power supplies under different operating conditions. The updated current and voltage values ​​are then transmitted to the dual-layer MPC controller 22. The optimal setpoint is calculated by the steady-state target calculation layer 221 and tracked in real time by the dynamic optimization control layer 222. The desired current values ​​of the three power supplies are then transmitted to the execution module 3. In this embodiment, the execution module 3 uses a PI controller. The switching duty cycle of the three-power-supply DC / DC converter is obtained by solving the PI controller. The three sets of duty cycles are then output to the first DC / DC converter 111, the second DC / DC converter 121, and the third DC / DC converter 131 to realize the switching action, thereby enabling the low-speed vehicle lithium battery power system of the present invention to achieve fast and accurate closed-loop control.

[0035] In summary, the low-speed vehicle lithium battery power system disclosed in this invention stores electrical energy through an energy storage module and can supply power to the load. During this process, the control strategy module monitors the voltage and current parameters of the energy storage module in real time and calculates the expected output values ​​to the execution module. The execution module controls the output voltage and output current of the energy storage module according to the expected values ​​of current and voltage, thereby realizing the automatic control of the low-speed lithium battery power system. The control strategy module includes an event-driven mechanism unit and a two-layer MPC controller. The voltage and current values ​​collected by the first lithium battery, the second lithium battery, and the supercapacitor are transmitted to the control strategy module. The event-driven mechanism unit updates the current and voltage values ​​of the three power sources under different operating conditions of the power system. The updated current and voltage values ​​are then transmitted to the two-layer MPC controller. The optimal setpoint is calculated by the steady-state target calculation layer, and the setpoint is tracked in real time by the dynamic optimization control layer. The desired current values ​​of the three power sources are then transmitted to the PI controller. The PI controller calculates the duty cycle of the three-power-source series DC / DC converter. The three duty cycles are then output to the first, second, and third DC / DC converters to realize the switching action, thereby enabling the low-speed vehicle lithium battery power system of the present invention to achieve fast and accurate closed-loop control.

[0036] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above 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.

[0037] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A low-speed vehicle lithium battery power system, characterized in that, include: The system includes an energy storage module, a control strategy module, and an execution module. The output terminal of the energy storage module is electrically connected to a load, and the output terminal of the energy storage module is electrically connected to the input terminal of the control strategy module. The output terminal of the control strategy module is electrically connected to the input terminal of the execution module, and the output terminal of the execution module is electrically connected to the input terminal of the energy storage module. The energy storage module includes a first lithium battery, a second lithium battery, a supercapacitor, and a DC bus. The output terminals of the first lithium battery, the second lithium battery, and the supercapacitor are electrically connected to the input terminal of the DC bus. The output terminals of the first lithium battery, the second lithium battery, and the supercapacitor are also electrically connected to the input terminal of the control strategy module. The input terminals of the first lithium battery, the input / output terminals of the second lithium battery, and the supercapacitor are electrically connected to the output terminal of the execution module. The control strategy module includes an event-driven mechanism unit and a two-layer MPC controller. The input terminal of the event-driven mechanism unit is electrically connected to the output terminal of the first lithium battery, the output terminal of the second lithium battery, and the output terminal of the supercapacitor, respectively. The output terminal of the event-driven mechanism unit is electrically connected to the input terminal of the two-layer MPC controller. The output terminal of the two-layer MPC controller is electrically connected to the input terminal of the execution module.

2. The low-speed vehicle lithium battery power system according to claim 1, characterized in that, The first lithium battery is also provided with a first DC / DC converter, and the first lithium battery is connected in series with the first DC / DC converter.

3. The low-speed vehicle lithium battery power system according to claim 2, characterized in that, The first DC / DC converter is configured as a bidirectional DC / DC converter.

4. The low-speed vehicle lithium battery power system according to claim 3, characterized in that, The second lithium battery is also provided with a second DC / DC converter, and the second lithium battery is connected in series with the second DC / DC converter.

5. The low-speed vehicle lithium battery power system according to claim 4, characterized in that, The second DC / DC converter is configured as a bidirectional DC / DC converter.

6. The low-speed vehicle lithium battery power system according to claim 5, characterized in that, The supercapacitor is also equipped with a third DC / DC converter, and the supercapacitor is connected in series with the third DC / DC converter.

7. The low-speed vehicle lithium battery power system according to claim 6, characterized in that, The third DC / DC converter is configured as a bidirectional DC / DC converter.

8. The low-speed vehicle lithium battery power system according to claim 7, characterized in that, The first lithium battery, the second lithium battery, and the supercapacitor are respectively connected in parallel to the input terminal of the DC bus through the first DC / DC converter, the second DC / DC converter, and the third DC / DC converter.

9. The low-speed vehicle lithium battery power system according to claim 8, characterized in that, The dual-layer MPC controller includes a steady-state target calculation layer and a dynamic optimization control layer.

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