Energy management system and control method thereof

Abstract

The present invention discloses an energy management system and a control method thereof. The energy management system is used for a fuel cell vehicle power system, and includes: a first type of energy storage device, which is used to absorb the braking energy transmitted from the motor system when the vehicle enters an electric braking state; a DC voltage converter, which is located between the first type of energy storage device and the second type of energy storage device, and is used to transfer the braking energy to the second type of energy storage device according to a preset power; a second type of energy storage device, which is used to absorb and store braking energy, and provide the motor system with the power required for vehicle operation by cooperating with a fuel cell when the vehicle enters a starting or normal driving state; a fuel cell. The present invention can fully recover braking energy and can improve the life and durability of the fuel cell.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics, and in particular to an energy management system and a control method thereof for a fuel cell vehicle power system. Background Art

[0002] With the development of fuel cell vehicle technology, the research on fuel cell vehicle power system has also become a focus. The main goal of fuel cell vehicle power system is to provide the vehicle with various types of energy required for starting, driving and braking. It is required to be energy-saving and durable, and each component of the power system can serve the entire vehicle life cycle.

[0003] The existing fuel cell vehicle power unit mainly includes motors, motor controllers, power batteries, fuel cell systems, etc. Some other fuel cell vehicle power units also include supercapacitors, or directly use supercapacitors as power batteries, etc. These solutions have the following disadvantages: 1. Braking energy cannot be fully recovered, resulting in energy waste; 2. Although some power units have the ability to recover braking energy, the load power fluctuation of the feedback braking energy is large, which is not conducive to the stable application of the original energy management algorithm, resulting in a decrease in the life of the fuel cell and the power battery, and generating higher energy consumption.

[0004] Therefore, the prior art needs to provide a technical solution that can solve at least one of the above technical problems. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides an energy management system, which is used for a fuel cell vehicle power system, comprising: a first type of energy storage device, which is used to absorb the braking energy transmitted from the motor system when the vehicle enters an electric braking state; a DC voltage converter, which is located between the first type of energy storage device and the second type of energy storage device, and is used to transfer the braking energy to the second type of energy storage device according to a preset power; the second type of energy storage device, which is used to absorb and store the braking energy, and when the vehicle enters a starting or normal driving state, it cooperates with the fuel cell to provide the motor system with the power required for vehicle operation; the fuel cell.

[0006] Preferably, the energy management system also includes: a first transmission device, which is located between the first type of energy storage device and the motor system, and is used to transmit the braking energy from the motor system to the first type of energy storage device when the vehicle enters an electric braking state, and to cut off the electric energy output of the first type of energy storage device when the vehicle enters a starting or normal driving state; a second transmission device, whose first end is respectively connected to the second type of energy storage device and the fuel cell, and whose second end is connected to the motor system, and is used to cut off the transmission of the braking energy of the motor system to the second type of energy storage device and / or the fuel cell when the vehicle enters an electric braking state, and to transmit the electric energy output by the second type of energy storage device and / or the fuel cell to the motor system when the vehicle enters a starting or normal driving state.

[0007] Preferably, the anode of the first transmission device is connected to the motor system, and the cathode of the first transmission device is connected to the first type of energy storage device; the anode of the second transmission device is connected to the second type of energy storage device and the motor system respectively, and the cathode of the second transmission device is connected to the motor system.

[0008] Preferably, the first type of energy storage device adopts a power battery or a supercapacitor; the second type of energy storage device adopts an energy battery.

[0009] Preferably, the system also includes: a control device, which is respectively connected to the first type of energy storage device, the second type of energy storage device, the DC voltage converter and the fuel cell, and is used to diagnose the operating status of the entire vehicle, and to control the power source and energy recovery of the vehicle by monitoring the remaining power of the first type of energy storage device and the second type of energy storage device.

[0010] Preferably, the control device is further used to control the vehicle to switch from the electric braking mode to the air braking mode when it is detected that the remaining power of the first type energy storage device exceeds a preset first type power high safety threshold.

[0011] Preferably, the control device is also used to control the second-type energy storage device to provide operating energy for the vehicle when it is detected that the remaining power of the second-type energy storage device exceeds a preset second-type power high safety threshold, and control the fuel cell to operate or stop working according to a preset fuel cell low power.

[0012] Preferably, the control device is further used to control the fuel cell to charge the second-type energy storage device when it is detected that the remaining power of the second-type energy storage device is lower than a preset second-type low power safety threshold, and control the fuel cell and the second-type energy storage device to provide operating energy for the vehicle at the same time, wherein the current operating power of the fuel cell is the maximum operating power of the fuel cell.

[0013] Preferably, the control device is further used to control the fuel cell to operate at a preset specified power ratio according to the remaining power of the second-type energy storage device when it is detected that the remaining power of the second-type energy storage device is within a preset second-type medium safety threshold range, so that the second-type energy storage device and the fuel cell can provide operating energy for the vehicle at the same time.

[0014] On the other hand, the present invention also provides a control method for an energy management system, which is executed using the energy management system described above, and the control method includes: when the entire vehicle enters an electric braking state, a first type of energy storage device absorbs braking energy transmitted from the motor system; a DC voltage converter transfers the braking energy to a second type of energy storage device according to a preset power; the second type of energy storage device absorbs and stores the braking energy, wherein, when the vehicle enters a starting or normal driving state, the second type of energy storage device cooperates with the fuel cell to provide the motor system with the power required for vehicle operation.

[0015] Compared with the prior art, one or more embodiments of the above scheme may have the following advantages or beneficial effects:

[0016] The present invention provides an energy management system and a control method for a fuel cell vehicle power system. The system and method connect a power-type power battery, an energy-type power battery, and a fuel cell engine through a conversion transmission device, and utilize their respective characteristics to optimize the energy management process, thereby achieving the purpose of energy saving and improving durability. Among them, when the vehicle is in an electric braking condition, the power-type battery and the energy-type battery are used in combination to fully absorb the electric braking power; when the vehicle is in a starting or normal driving condition, the energy-type battery and / or the fuel cell are used in combination to provide the energy required for the operation of the entire vehicle. In this way, the present invention fully recovers the braking energy to achieve the purpose of energy saving, while also ensuring that the SOC fluctuation of the energy-type battery decreases, thereby reducing the power fluctuation of the fuel cell engine, which is beneficial to prolonging the life of the fuel cell and improving the durability of the fuel cell.

[0017] Although the present invention will be described below in conjunction with some exemplary implementations and methods of use, it should be understood by those skilled in the art that it is not intended to limit the present invention to these embodiments. On the contrary, it is intended to cover all substitutes, modifications and equivalents within the spirit and scope of the present invention defined by the appended claims.

[0018] Other advantages, objectives, and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the following description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0020] Figure 1 This is the first example of the overall structural diagram of the energy management system according to an embodiment of the present application.

[0021] Figure 2 This is the second example of the overall structural diagram of the energy management system according to an embodiment of the present application.

[0022] Figure 3 This is a schematic diagram of the circuit structure of the energy management system according to an embodiment of the present application.

[0023] Figure 4 This is a step diagram of a control method for an energy management system according to an embodiment of the present application. DETAILED DESCRIPTION

[0024] The following will describe the implementation methods of the present invention in detail with reference to the accompanying drawings and embodiments, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. It should be noted that as long as there is no conflict, the various embodiments of the present invention and the various features in the embodiments can be combined with each other, and the technical solutions formed are all within the protection scope of the present invention.

[0025] Meanwhile, in the following description, many specific details are set forth for the purpose of explanation to provide a thorough understanding of the embodiments of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without the specific details or the specific manner described herein.

[0026] With the development of fuel cell vehicle technology, the research on fuel cell vehicle power system has also become a focus. The main goal of fuel cell vehicle power system is to provide the vehicle with various types of energy required for starting, driving and braking. It is required to be energy-saving and durable, and each component of the power system can serve the entire vehicle life cycle.

[0027] The existing fuel cell vehicle power unit mainly includes motors, motor controllers, power batteries, fuel cell systems, etc. Some other fuel cell vehicle power units also include supercapacitors, or directly use supercapacitors as power batteries, etc. These solutions have the following disadvantages: 1. Braking energy cannot be fully recovered, resulting in energy waste; 2. Although some power units have the ability to recover braking energy, the load power of the feedback braking energy fluctuates greatly, which is not conducive to the stable application of the energy management algorithm, resulting in a decrease in the life of the fuel cell and the power battery, and generating higher energy consumption.

[0028] In order to solve at least one of the above technical problems, the present invention provides an energy management system and a control method for a fuel cell vehicle power system. The system and method at least include: a first type of energy storage device, a second type of energy storage device, a DC voltage converter and a fuel cell (system) arranged between the two types of energy storage devices. In addition, the system also includes: a first transmission device located between the first type of energy storage device and the vehicle motor system, and a second transmission device whose first end is connected to the second type of energy storage device and the fuel cell, and whose second end is connected to the vehicle motor system. Thus, by utilizing the forward conduction and reverse cutoff characteristics of the two types of transmission devices, when the vehicle is in an electric braking state, the first type of energy storage device with a higher charging power is used to absorb the braking energy, and the DC voltage converter is used to make the second type of energy storage device store the current braking energy, so that when the vehicle is in a starting or normal operating state, the second type of energy storage device and / or the fuel cell provide the power required in the normal operation process such as driving or starting of the vehicle. In this way, the present invention can fully recover the braking energy and improve the life of the fuel cell by utilizing the above topological structure, while reducing the power fluctuation of the fuel cell.

[0029] Figure 1 This is the first example of the overall structural diagram of the energy management system of the embodiment of the present application. Figure 1 As shown, the energy management system of the present invention is applied to a fuel cell electric vehicle power system, wherein the energy management system at least comprises: a first type energy storage device 10 , a second type energy storage device 20 , a DC voltage converter 30 and a fuel cell 40 .

[0030] The first type of energy storage device 10 is used to absorb the braking energy transmitted from the (vehicle) motor system when the vehicle enters the electric braking state, and output the currently absorbed braking energy to the DC voltage converter at a preset power. The DC voltage converter 30 is located between the first type of energy storage device 10 and the second type of energy storage device 20, and is used to transfer the current braking energy obtained from the first type of energy storage device 10 to the second type of energy storage device 20 according to the preset power. The second type of energy storage device 20 is used to absorb and store the current braking energy obtained from the DC voltage converter 30. Among them, the second type of energy storage device 20 is also used to provide the (vehicle) motor system with the power required for vehicle operation under the coordinated control of the second type of energy storage device 20 and the fuel cell 40 when the vehicle enters the starting or normal driving state. At the same time, the first type of energy storage device 10 is also used to maintain the minimum remaining power state when the vehicle enters the starting or normal driving state.

[0031] In actual application, the vehicle motor system is a system used as a vehicle power drive device to provide the vehicle with the power required for various driving states, including a motor and a motor controller. The vehicle motor system operates after obtaining the power energy of various power sources, and controls the vehicle's starting, normal driving, braking, and steering states under the action of the corresponding motor control algorithm.

[0032] Specifically, the first type of energy storage device 10 uses a power battery (for example, a lithium titanate battery, a lithium manganate battery, etc.) or a supercapacitor. The second type of energy storage device 20 uses an energy battery (for example, a lithium iron phosphate battery, a lithium manganate battery, etc.). The DC voltage converter 30 uses a DC / DC converter, and the input end of the DC voltage converter 30 is connected to the first type of energy storage device 10, and the output end of the first type of energy storage device 10 is connected to the second type of energy storage device 20. The DC voltage converter 30 is used to obtain the braking energy transmitted by the first type of energy storage device 10 at a preset power, and after the braking energy is converted into voltage, it is transmitted to the second type of energy storage device 20 for storage.

[0033] When the vehicle enters the electric braking condition, the braking energy fed back from the motor system is absorbed by the first type energy storage device 10. Since the charging power of the power battery is high, the high-power braking energy generated by the vehicle's electric braking can be fully absorbed by the first type energy storage device 10, and then slowly charged to the second type energy storage device 20 with a smaller power through the DC voltage converter 30. In addition, when the vehicle is in the starting or normal operating condition, the first type energy storage device 10 maintains the lowest power state; at the same time, the second type energy storage device 20 uses its own stored energy in combination with the fuel cell 40 to provide the motor system in the vehicle with all the energy required for starting or normal operation.

[0034] It should be noted that the above-mentioned preset power needs to be less than the charging power of the first type energy storage device 10, and the present invention does not specifically limit this. Preferably, the size of the preset power should be consistent with the power corresponding to the first type energy storage device 10 being in the following first type low power safety threshold operating state, so that the power type battery is at the lowest value of the allowable remaining power range of this type of battery during normal operation, and further enables the DC / DC to evenly transfer the energy in the power type battery to the energy type battery.

[0035] In this way, by utilizing the above-mentioned topological structure and functions, the power type battery and the energy type battery are used in combination, and the electric braking power can be fully absorbed.

[0036] Furthermore, in order to simplify the control strategy of the energy management system, the energy management system of the present invention further includes: a first transmission device 50 and a second transmission device 60 . Figure 2 This is the second example of the overall structural diagram of the energy management system according to an embodiment of the present application. Figure 3 FIG. 1 is a schematic diagram of the circuit structure of the energy management system of the embodiment of the present application. Figure 2 , Figure 3 As shown, the first transmission device 50 is located between the first type energy storage device 10 and the motor system; the first end of the second transmission device 60 is connected to the second type energy storage device 20 and the fuel cell 40 respectively, and the second end of the second transmission device 60 is connected to the motor system.

[0037] In one embodiment, the first transmission device 50 is used to transmit the braking energy obtained from the motor system to the first type of energy storage device 10 when the vehicle enters the electric braking state. In addition, the second transmission device 60 is used to cut off the transmission of the braking energy of the motor system to the second type of energy storage device 20 and / or the fuel cell 40 when the vehicle enters the electric braking state. In this way, when the vehicle is in the electric braking state, the braking energy fed back by the motor system will only be transmitted to the first type of energy storage device 10, and cannot be transmitted to the second type of energy storage device 20 and / or the fuel cell 40, so that the braking energy fed back by the motor system can only be absorbed by the power battery with a higher charging power.

[0038] In another embodiment, the first transmission device 50 is used to cut off the power output state of the first type energy storage device 10 when the vehicle enters the starting or normal driving state (that is, control the first type energy storage device 10 to be in a state of not outputting power). In addition, the second transmission device 60 is used to transmit the power output by the second type energy storage device 20 and / or the fuel cell 40 to the motor system when the vehicle enters the starting or normal driving state. In this way, when the vehicle is in the starting or normal driving state, only the second type energy storage device 20 and / or the fuel cell 40 is used as a vehicle power source providing device, and the first type energy storage device 10 is not used to provide energy for the motor system, so that when the vehicle is in the starting or normal driving state, the motor system only obtains the energy of the second type energy storage device 20 and / or the fuel cell 40 fed back to drive the normal operation of the vehicle.

[0039] Further, if Figure 3 As shown, the first transmission device 50 uses a diode D1, and the second transmission device 60 uses a diode D2. The anode of the first transmission device 50 is connected to the motor system, and the cathode of the first transmission device 60 is connected to the first type of energy storage device 10. The anode of the second transmission device 60 is connected to the first type of energy storage device 10 and the motor system, and the cathode of the second transmission device 60 is connected to the motor system. At the same time, the anode of the first transmission device 50 is connected to the cathode of the second transmission device 60.

[0040] In order to better realize the dispatching management and control between various energy providing devices and energy recovery devices in the energy management system, the energy management system described in the embodiment of the present invention also includes: a control device 70. Among them, the control device 70 is respectively connected to the first type of energy storage device 10, the second type of energy storage device 20, the DC voltage converter 30 and the fuel cell 40. The control device 70 is used to diagnose the operating status of the whole vehicle, and to control the power source and energy recovery of the vehicle by monitoring the remaining power of the first type of energy storage device 10 (recorded as "first remaining power") and the remaining power of the second type of energy storage device (recorded as "second remaining power").

[0041] It should be noted that, in the embodiment of the present invention, the control device 70 can be configured independently or in a motor controller in the motor system. The present invention does not make any specific limitation on this, and those skilled in the art can make settings according to actual conditions.

[0042] Specifically, in the embodiment of the present invention, the control device 70 is used to control the vehicle to switch from the electric braking mode to the air braking mode when it is detected that the current vehicle is in the electric braking condition and the remaining power of the first type energy storage device exceeds the preset first type power high safety threshold. That is to say, when the power battery SOC exceeds the maximum value of its own power allowable range, the control device 70 needs to control the whole vehicle to enter the air braking mode, so that the braking mode of the vehicle is switched from electric braking to air braking. At this time, the power battery does not need to recover braking energy.

[0043] Further, in an embodiment of the present invention, the control device 70 is used to control the remaining power of the first type energy storage device 10 to be in the first type low power safety threshold operating state when it is detected that the current vehicle is in an electric braking condition, and transmit the currently absorbed braking energy to the second type energy storage device 20 through the DC voltage converter 30 at a preset power, so that the second type energy storage device 20 absorbs the current braking energy. In this way, the present invention performs power output operation by controlling the remaining power of the power battery to be at the lowest value of its own power allowable range, so that the DC / DC transfers the energy in the power battery to the energy battery evenly. It should be noted that the above-mentioned first type low power safety threshold and the first type high power safety threshold are the minimum and maximum values ​​of the remaining power allowed by the first type energy storage device 10 under normal working conditions. The embodiment of the present invention does not limit the specific values ​​of these two thresholds, and those skilled in the art can set them according to various actual needs such as the performance of the power battery (for example: charging power).

[0044] Furthermore, in an embodiment of the present invention, the control device 70 is used to, when it is detected that the current vehicle is in a starting or normal driving condition, on the one hand, control the remaining power of the second type of energy storage device 20 to operate within a normal working range according to the detected remaining power of the second type of energy storage device 20 using an energy management algorithm, so that the second type of energy storage device 20 and / or the fuel cell 40 cooperate with each other to provide the vehicle with the energy required for the current operation.

[0045] In this way, the embodiment of the present invention utilizes the control device 70 to control the braking energy recovery of the first type energy storage device 10 and the second type energy storage device 20 under the vehicle braking condition, and to control the power source of the second type energy storage device 20 and / or the fuel cell 40 when the vehicle is in the starting or normal driving condition, so as to keep the power fluctuation of the fuel cell engine as small as possible and keep the hydrogen consumption of the entire system low.

[0046] In an embodiment of the present invention, when the vehicle is in a starting or normal driving condition, the second type energy storage device 20 and / or the fuel cell 40 both serve as power source driving devices for the vehicle when driving, and the energy supply ratio between the two varies with the remaining power of the second type energy storage device 20. This ratio needs to be further detected and controlled by the control device 70.

[0047] Specifically, in the first embodiment, the control device 70 is also used to control the second type of energy storage device 20 to provide operating energy for the vehicle, and control the fuel cell 40 to operate or stop working according to the preset fuel cell low power when it is detected that the current vehicle is in a starting or normal driving condition. If it is detected that the remaining power (second remaining power) of the second type of energy storage device 20 exceeds the preset second type of power high safety threshold, it controls the second type of energy storage device 20 to provide operating energy for the vehicle, and controls the fuel cell 40 to operate or stop working according to the preset fuel cell low power. In this way, when the SOC of the energy-type battery is too high, the power required by the whole vehicle is mainly provided by the energy-type battery, and the generator in the fuel cell operates at a lower power or even stops working. It should be noted that the above-mentioned fuel cell low power is preferably the minimum operating power of the fuel cell. The present invention does not specifically limit this parameter, and those skilled in the art can set it according to factors such as the performance of the fuel cell.

[0048] In the second embodiment, the control device 70 is also used to control the fuel cell 40 to charge the second type energy storage device 20 when it is detected that the current vehicle is in a starting or normal driving condition, and to control the fuel cell 40 and the second type energy storage device 20 to provide operating energy for the vehicle at the same time, if it is detected that the remaining power (second remaining power) of the second type energy storage device 20 is lower than the preset second type low power safety threshold. The current operating power of the fuel cell is the maximum operating power of the fuel cell 40.

[0049] Furthermore, the control device 70 is also used to control the fuel cell 40 to charge the second type energy storage device 20 when it is detected that the current vehicle is in the starting or normal driving condition, if it is detected that the remaining power (second remaining power) of the second type energy storage device 20 is lower than the preset second type low power safety threshold. At this time, the control device 70 is also used to control the fuel cell 40 and the second type energy storage device 20 to provide operating energy for the vehicle at the same time if it is detected that the power required by the current vehicle belongs to the high demand power state during the process of controlling the fuel cell 40 to charge the second type energy storage device 20, wherein the current operating power of the fuel cell is the maximum operating power of the fuel cell 40. That is to say, when the SOC of the energy type battery is too low, the generator in the fuel cell charges the energy type battery. If the vehicle needs a larger power at this time, the generator in the fuel cell provides the required power to the vehicle at the maximum power in cooperation with the energy type battery.

[0050] In the third embodiment, the control device 70 is also used to control the fuel cell 40 to operate according to the preset rated (rated) power ratio according to the residual power of the second type of energy storage device 20 when it is detected that the current vehicle is in the starting or normal driving condition, if it is detected that the remaining power (second remaining power) of the second type of energy storage device 20 belongs to the preset second type of power medium safety threshold, so that the second type of energy storage device 20 and the fuel cell 40 simultaneously provide the energy required for the vehicle to operate. Thus, when the energy type battery SOC is at a medium level, the current operating power of the engine in the fuel cell is determined according to the range level of the energy type battery SOC, and different medium range levels of the second remaining power correspond to the corresponding designated operating power of the fuel cell engine. Among them, the lower the numerical level of the second remaining power, the higher the designated operating power of the current fuel cell engine.

[0051] Preferably, in the embodiment of the present invention, the control device 70 is further used to control the fuel cell engine to operate at rated power when it is detected that the second remaining power belongs to the first medium range. The first medium range is 20% to 40% (including 20% ​​and 40%) of the total power of the second type energy storage device 20.

[0052] Preferably, in the embodiment of the present invention, the control device 70 is further used to control the fuel cell engine to operate at a specified power corresponding to the product of the rated power and the first proportional threshold value when it is detected that the second remaining power belongs to the second medium range. The second medium range is 40% to 60% (excluding 40% and including 60%) of the total power of the second type energy storage device 20. The first proportional threshold value is preferably 60%.

[0053] Preferably, in the embodiment of the present invention, the control device 70 is further used to control the fuel cell engine to operate at a specified power corresponding to the product of the rated power and the second proportional threshold value when it is detected that the second remaining power belongs to the third medium range. The third medium range is 60% to 80% (excluding 60% and including 80%) of the total power of the second type energy storage device 20. The second proportional threshold value is preferably 30%.

[0054] It should be noted that the above-mentioned second-category low power safety threshold and the second-category high power safety threshold are respectively the minimum and maximum values ​​of the remaining power allowed by the second-category energy storage device 20 under normal working conditions. The embodiments of the present invention do not limit the specific values ​​of these two thresholds, and those skilled in the art may set them according to various actual needs such as the performance of the type battery (for example: charging power, discharging power). In addition, the above-mentioned second-category medium power safety threshold is the remaining power range allowed by the second-category energy storage device 20 under normal working conditions, and the remaining power range is between the above-mentioned second-category low power safety threshold and the second-category high power safety threshold.

[0055] In summary, the embodiment of the present invention uses power type batteries and energy type batteries in combination, which can fully absorb electric braking power, while ensuring the reduction of SOC fluctuations of the energy type batteries, thereby reducing the power fluctuations of the fuel cell engine, which is beneficial to improving the life of the fuel cell.

[0056] On the other hand, based on the above energy management system, the present invention further proposes a control method for the energy management system, and the control method is executed by using the above energy management system. Figure 4 This is a step diagram of a control method for an energy management system according to an embodiment of the present application.

[0057] like Figure 4 As shown, in step S410, when the vehicle enters the electric braking state, the first type energy storage device 10 absorbs the braking energy transmitted from the motor system; in step S420, the DC voltage converter 30 transmits the currently absorbed braking energy to the second type energy storage device 20 according to the preset power; in step S430, the second type energy storage device 20 absorbs the current braking energy from the DC voltage converter 30 and stores it. When the vehicle enters the starting or normal driving state, the second type energy storage device 20 cooperates with the fuel cell 40 to provide the motor system with the power required for vehicle operation.

[0058] The present invention proposes an energy management system and a control method for a fuel cell vehicle power system. The system and method connect a power-type power battery, an energy-type power battery, and a fuel cell engine through a conversion transmission device, and use their respective characteristics to optimize the energy management process, thereby achieving energy saving and improving durability. Among them, when the vehicle is in an electric braking condition, the power-type battery and the energy-type battery are used in combination to fully absorb the electric braking power; when the vehicle is in a starting or normal driving condition, the energy-type battery and / or the fuel cell are used in combination to provide the energy required for the operation of the entire vehicle. In this way, the present invention fully recovers the braking energy to achieve the purpose of energy saving, while also ensuring that the SOC fluctuation of the energy-type battery decreases, thereby reducing the power fluctuation of the fuel cell engine, which is beneficial to prolonging the life of the fuel cell and improving the durability of the fuel cell.

[0059] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any person familiar with the technology within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

[0060] It should be understood that the embodiments disclosed in the present invention are not limited to the specific structures, processing steps or materials disclosed herein, but should be extended to equivalent substitutions of these features understood by ordinary technicians in the relevant field. It should also be understood that the terms used herein are only used for the purpose of describing specific embodiments and are not meant to be limiting.

[0061] The "one embodiment" or "embodiment" mentioned in the specification means that the specific features, structures or characteristics described in conjunction with the embodiment are included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment" or "embodiment" appearing in various places throughout the specification do not necessarily refer to the same embodiment.

[0062] Although the embodiments disclosed in the present invention are as above, the above contents are only embodiments adopted for facilitating the understanding of the present invention and are not intended to limit the present invention. Any technician in the technical field to which the present invention belongs can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. An energy management system, characterized in that: The energy management system is used for a fuel cell vehicle power system, and includes: The first type of energy storage device is used to absorb the braking energy transmitted from the motor system when the vehicle enters the electric braking state; a direct current voltage converter, located between the first type of energy storage device and the second type of energy storage device, for transmitting the braking energy to the second type of energy storage device according to a preset power; The second type of energy storage device is used to absorb and store the braking energy, and to provide the motor system with the power required for vehicle operation by cooperating with the fuel cell when the vehicle enters the starting or normal driving state; The fuel cell; a first transmission device, located between the first type of energy storage device and the motor system, for transmitting the braking energy from the motor system to the first type of energy storage device when the vehicle enters an electric braking state, and for cutting off the electric energy output of the first type of energy storage device when the vehicle enters a starting or normal driving state; A second transmission device, a first end of which is respectively connected to the second type of energy storage device and the fuel cell, and a second end of which is connected to the motor system, is used to cut off the transmission of the braking energy of the motor system to the second type of energy storage device and / or the fuel cell when the vehicle enters an electric braking state, and to transmit the electric energy output by the second type of energy storage device and / or the fuel cell to the motor system when the vehicle enters a starting or normal driving state.

2. The energy management system according to claim 1, characterized in that: The anode of the first transmission device is connected to the motor system, and the cathode of the first transmission device is connected to the first type of energy storage device; The anode of the second transmission device is connected to the second type energy storage device and the motor system respectively, and the cathode of the second transmission device is connected to the motor system.

3. The energy management system according to claim 1 or 2, characterized in that: The first type of energy storage device uses a power battery or a supercapacitor; The second type of energy storage device uses an energy-type battery.

4. The energy management system according to claim 1 or 2, characterized in that: The system further comprises: A control device is respectively connected to the first type of energy storage device, the second type of energy storage device, the DC voltage converter and the fuel cell, and is used to diagnose the operating status of the entire vehicle, and to control the power source and energy recovery of the vehicle by monitoring the remaining power of the first type of energy storage device and the second type of energy storage device.

5. The energy management system according to claim 4, characterized in that: The control device is also used to control the vehicle to switch from the electric braking mode to the air braking mode when it is detected that the remaining power of the first type energy storage device exceeds a preset first type power high safety threshold.

6. The energy management system according to claim 4, characterized in that: The control device is further used to control the second-type energy storage device to provide operating energy for the vehicle when it is detected that the remaining power of the second-type energy storage device exceeds a preset second-type power high safety threshold, and control the fuel cell to operate or stop working according to a preset fuel cell low power.

7. The energy management system according to claim 4, characterized in that: The control device is further used to control the fuel cell to charge the second-type energy storage device when it is detected that the remaining power of the second-type energy storage device is lower than a preset second-type low power safety threshold, and control the fuel cell and the second-type energy storage device to simultaneously provide operating energy for the vehicle, wherein the current operating power of the fuel cell is the maximum operating power of the fuel cell.

8. The energy management system according to claim 4, characterized in that: The control device is further used to control the fuel cell to operate at a preset specified power ratio based on the remaining power of the second-type energy storage device when it is detected that the remaining power of the second-type energy storage device is within a preset second-type medium safety threshold range, so that the second-type energy storage device and the fuel cell provide operating energy for the vehicle at the same time.

9. A control method for an energy management system, characterized in that: The control method is executed by using the energy management system according to any one of claims 1 to 8, and the control method includes: When the vehicle enters the electric braking state, the first type of energy storage device absorbs the braking energy transmitted from the motor system; The DC voltage converter transfers the braking energy to the second type of energy storage device according to a preset power; The second type of energy storage device absorbs and stores the braking energy, wherein when the vehicle enters a starting or normal driving state, the second type of energy storage device cooperates with the fuel cell to provide the motor system with the power required for vehicle operation.

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