A hydrogen-powered vehicle active discharge circuit, system and strategy

Abstract

The present invention provides a hydrogen energy vehicle active discharge circuit, system and strategy, including a power module, a PDU high voltage power distribution and pre-charging module and a pre-charging capacitor module, wherein the power module, the PDU high voltage power distribution and pre-charging module and the pre-charging capacitor module are sequentially connected in series to form a discharge circuit; the power module includes a power contactor, a first power battery and a second power battery connected in series, the first power battery and the second power battery provide energy for the fuel cell vehicle, and the power contactor is used to shut down the circuit. The present invention uses step-down DC to output the energy contained in the pre-charging capacitor to the vehicle battery, which not only realizes the discharge of the pre-charging capacitor, but also stores the capacitor's electricity in the vehicle battery, avoiding energy waste and the risk of vehicle shaking caused by motor rotation.

Description

Technical Field

[0001] The present invention relates to the technical field of pre-charging circuits for fuel cell vehicles, and in particular to an active discharge circuit, system and strategy for hydrogen energy vehicles. Background Art

[0002] With the promotion and popularization of hydrogen fuel cell new energy vehicles, more and more automobile companies have begun to focus on the research and development of hydrogen fuel cell new energy vehicles. Since hydrogen fuel cell vehicles have many more high-voltage devices (stack boost DC, supercapacitor boost DC, hydrogen fuel cell air compressor controller, etc.) than traditional new energy vehicles, there are more high-voltage loads in the circuit, and the high-voltage structure is complex, so more capacitor energy needs to be actively discharged. Although the current method of motor winding discharge has a fast discharge speed, the energy released during the discharge process causes energy waste. At the same time, due to excessive energy, if it is not properly controlled, it may cause phenomena such as motor rotation and vehicle shaking. Summary of the invention

[0003] A major problem solved by the present invention is that the existing motor winding discharge method wastes a lot of energy and easily causes the vehicle to shake.

[0004] In order to solve the above problems, according to one aspect of the present invention, the present invention provides an active discharge circuit for a hydrogen-powered vehicle, comprising:

[0005] A power supply module, a PDU high-voltage power distribution and pre-charging module and a pre-charging capacitor module, wherein the power supply module, the PDU high-voltage power distribution and pre-charging module and the pre-charging capacitor module are connected in series in sequence to form a discharge circuit;

[0006] The power module includes a power contactor, a first power battery and a second power battery connected in series, the first power battery and the second power battery provide energy for the fuel cell vehicle, and the power contactor is used to shut down the circuit.

[0007] Furthermore, the PDU high voltage power distribution and pre-charging module includes:

[0008] A pre-charging resistor, a main pre-charging contactor, a hydrogen fuel pre-charging contactor and an auxiliary pre-charging contactor, wherein the input end of the pre-charging resistor is connected to the output end of the power module;

[0009] The output end of the pre-charging resistor is respectively connected to the input end of the main pre-charging contactor, the hydrogen fuel pre-charging contactor and the auxiliary pre-charging contactor;

[0010] The main pre-filling contactor, the hydrogen fuel pre-filling contactor and the auxiliary pre-filling contactor are connected in parallel.

[0011] Furthermore, one end of the main contactor is connected to the output end of the power module, the main contactor and the main pre-charge contactor are connected in parallel to form a first loop, and the output end of the first loop is connected to the input end of the pre-charge capacitor module.

[0012] Furthermore, one end of the hydrogen fuel contactor is connected to the output end of the power module, the hydrogen fuel pre-charging contactor and the hydrogen fuel contactor are connected in parallel to form a second loop, and the output end of the second loop is connected to the input end of the pre-charging capacitor module.

[0013] Furthermore, one end of the auxiliary contactor is connected to the output end of the power module, the auxiliary contactor and the main contactor are connected in parallel to form a third loop, and the output end of the third loop is connected to the input end of the pre-charge capacitor module.

[0014] Furthermore, the first circuit, the second circuit and the third circuit are respectively connected in series with a first fuse, a second fuse and a third fuse;

[0015] The output ends of the first fuse, the second fuse and the third fuse are respectively connected to the input end of the pre-charge capacitor module.

[0016] Furthermore, the pre-charge capacitor module comprises:

[0017] A drive motor system, wherein the input end of the drive motor system is connected to the output end of the first fuse, the output end of the drive motor system is connected to the input end of the power module, a fourth fuse and a supercapacitor bidirectional DC converter are connected in series, and the input end of the first fuse is connected to the output end of the main pre-charge contactor, and the output end of the supercapacitor bidirectional DC converter is connected to the input end of the power module;

[0018] A stack air compression system, wherein the input end of the stack air compression system is connected to the output end of the second fuse, the output end of the stack air compression system is connected to the input end of the power module, the fifth fuse and the stack boost DC converter are connected in series, and the input end of the fifth fuse is connected to the output end of the hydrogen fuel pre-filling contactor, and the output end of the supercapacitor bidirectional DC converter is connected to the input end of the power module;

[0019] An air-conditioning compressor module, wherein the input end of the air-conditioning compressor module is connected to the output end of the third fuse, the output end of the air-conditioning compressor module is connected to the input end of the power module, the sixth fuse and the step-down DC converter are connected in series, and the input end of the sixth fuse is connected to the output end of the auxiliary pre-charging contactor, and the output end of the step-down DC converter is connected to the input end of the power module.

[0020] Furthermore, the supercapacitor bidirectional DC converter, the drive motor system, the stack boost DC converter, the stack air compression system, the buck DC converter and the air-conditioning compressor module are respectively connected in parallel with a pre-charge capacitor.

[0021] According to another aspect of the present invention, a hydrogen-powered vehicle active discharge system includes a vehicle controller, a supercapacitor, a supercapacitor bidirectional DC converter, a battery stack, a high-voltage distribution box, a step-down DC converter, a motor controller, a motor, a vehicle battery and a power battery system, characterized in that the hydrogen-powered vehicle active discharge system is configured with a hydrogen-powered vehicle active discharge circuit as described above:

[0022] The power battery system, the supercapacitor, the battery stack, the high-voltage distribution box and the step-down DC converter respectively feed back working status signals to the vehicle controller through the CAN bus network, and the vehicle controller is used to issue control instructions;

[0023] The power battery system, the battery stack, the supercapacitor, the motor and the step-down DC converter are respectively connected to the voltage output end of the high-voltage distribution box;

[0024] One end of the supercapacitor bidirectional DC converter is connected to the voltage input end of the supercapacitor, and the other end is connected to the voltage output end of the high-voltage distribution box;

[0025] The motor controller is arranged on the motor, and the motor controller is used as a component of the fuel cell vehicle to send a motor working status signal;

[0026] The output end of the step-down DC converter charges the vehicle battery.

[0027] According to another aspect of the present invention, a hydrogen-powered vehicle active discharge strategy is also disclosed. When the aforementioned hydrogen-powered vehicle active discharge system is in operation, it is used to implement the hydrogen-powered vehicle active discharge strategy, including:

[0028] Send a shutdown command to shut down the supercapacitor bidirectional DC converter, battery stack and motor controller;

[0029] When the total current of the high-voltage distribution box is less than the power-off threshold, the power contactor is disconnected;

[0030] Send active discharge command and step-down DC converter start-up command;

[0031] The step-down DC converter turns off the undervoltage detection and starts the wave, and discharges the power of the pre-charge capacitor.

[0032] The present invention provides an active discharge circuit, system and strategy for hydrogen energy vehicles. The active discharge circuit has the advantages of safe high-voltage system architecture, clear structural hierarchy, strong control logic, reliable control strategy, energy saving, etc. It can discharge the energy contained in the high-voltage capacitor, ensure high voltage safety, and achieve the purpose of energy saving. It can also effectively eliminate the risk of vehicle shaking caused by motor discharge, which is safer and more reliable, suitable for all new energy vehicle models, and has the characteristics of wide applicability and high practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings, which constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0034] Figure 1 Schematic diagram of the active discharge circuit of a hydrogen-powered vehicle in an embodiment of the present invention.

[0035] Figure 2 Schematic diagram of the active discharge system of a hydrogen-powered vehicle in an embodiment of the present invention.

[0036] Figure 3 This is a schematic diagram of the active discharge strategy process design for a hydrogen-powered vehicle in an embodiment of the present invention. DETAILED DESCRIPTION

[0037] Various exemplary embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention.

[0038] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0039] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0040] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0041] Technologies, methods, and apparatus known to ordinary technicians in the relevant field may not be discussed in detail, but where appropriate, such technologies, methods, and apparatus should be considered part of the authorization specification.

[0042] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0043] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0044] Embodiment 1, as Figure 1 As shown, it is a schematic diagram of a circuit of an active discharge system and strategy algorithm for a hydrogen-powered vehicle disclosed in this embodiment, which includes three large modules: module one 100: power module; module two 200: PDU high-voltage power distribution and pre-charging module; module three 300: pre-charging capacitor module.

[0045] Module 1 includes a power contactor 110, power batteries 120 and 130; the power batteries 120 and 130 provide energy for the vehicle to travel; the power contactor 110 is used to prevent the power battery from being directly connected to the outside, ensure high voltage safety, and reduce the risk of electric shock to personnel.

[0046] Module 2, including 210 main contactor, 220 main pre-charge contactor, fuse 1, fuse 2, 310 hydrogen fuel contactor, 320 hydrogen fuel pre-charge contactor, fuse 3, fuse 4, 410 auxiliary contactor, 420 auxiliary pre-charge contactor, fuse 5, fuse 6, 500 pre-charge resistor;

[0047] Among them, the pre-charging resistor 500 limits the pre-charging current size for the three pre-charging circuit loops to prevent the capacitive loads in the three pre-charging circuit loops from being charged, resulting in excessive circuit current and burning the fuse or sintering the contactor; fuses 1-6 protect the load current of each fuse circuit from being too large. When the current is too large, the circuit is cut off by fusing, thereby protecting the circuit.

[0048] Module three includes a main circuit consisting of 230 supercapacitor boost DC and its pre-charge capacitor 231, and 240 drive motor system and its pre-charge capacitor 241; 330 battery stack boost DC and its pre-charge capacitor 331, 340 battery stack air compression system and its pre-charge capacitor 341, a hydrogen fuel circuit; 450 step-down DC and its pre-charge capacitor 451 and 460 air conditioning compressor and its pre-charge capacitor 461. An auxiliary circuit; wherein, in the main circuit, the supercapacitor boost DC 230 can supply the energy of the supercapacitor to the drive motor system 240, and at the same time can absorb the electric energy generated by the feedback of the drive motor system 240, and the drive motor system System 240 can provide a power source for hydrogen-powered vehicles and generate electricity through feedback braking. In the hydrogen fuel cell circuit, the stack boost DC330 can increase the lower voltage of the stack to the power battery bus voltage, and supply the electricity generated by the hydrogen fuel cell to the high-voltage circuit of the hydrogen-powered vehicle. The stack air compression system 340 provides oxygen supply for the hydrogen fuel cell stack. In the auxiliary circuit, the step-down DC450 uses the high-voltage electricity of the hydrogen-powered vehicle to replenish the low-voltage battery. The air-conditioning compressor 460 provides cooling for the air-conditioning system. The pre-charged capacitors of each controller mainly play a role in voltage stabilization, and the power-off process requires the discharge of the pre-charged capacitors to prevent high-voltage electric shock.

[0049] The specific connection relationships among modules 1, 2 and 3 are:

[0050] In module 1, the input end of the drive motor system is connected to the output end of the fuse 1, the output end of the drive motor system is connected to the input end of the power module, the fuse 4 and the supercapacitor bidirectional DC are connected in series, and the input end of the fuse 1 is connected to the output end of the main pre-charge contactor, and the output end of the supercapacitor bidirectional DC is connected to the input end of the power module;

[0051] In module 2, the input end of the stack air compression system is connected to the output end of the fuse 2, the output end of the stack air compression system is connected to the input end of the power module, the fuse 5 and the stack boost DC converter are connected in series, and the input end of the fuse 5 is connected to the output end of the hydrogen fuel pre-filling contactor, and the output end of the supercapacitor bidirectional DC converter is connected to the input end of the power module;

[0052] In module three, the input end of the air-conditioning compressor module is connected to the output end of the fuse 3, the output end of the air-conditioning compressor module is connected to the input end of the power module, the fuse 6 and the step-down DC converter are connected in series, and the input end of the fuse 6 is connected to the output end of the auxiliary pre-charging contactor, and the output end of the step-down DC converter is connected to the input end of the power module.

[0053] Embodiment 2, as Figure 2, is a schematic diagram of an active discharge system for a hydrogen-powered vehicle of the present invention:

[0054] Among them, 20 is the power battery system, 22 is the VCU vehicle controller, 24 is the hydrogen fuel cell, 241 is the stack air compression system, 242 is the stack boost DC, 25 is the high-voltage distribution box, which is equipped with insurance and various contactors, 26 is a supercapacitor, 261 is a supercapacitor bidirectional DC, 23 is a step-down DC, 29 is a compressor, 21 is a car battery, 27 is a motor controller and a motor, and 28 is a reducer and a differential.

[0055] The controllers (20, 22, 23, 24, 241, 242, 25, 26, 261, 29 and 27) communicate and control each other through the CAN network. The high-voltage device loop is connected by high voltage, and the step-down DC output end is connected to the car battery to charge the car battery. The specific connection method of each controller module refers to the system principle. Figure 2 , specifically:

[0056] The power battery system 20, the supercapacitor 26, the hydrogen fuel cell 24 (fuel cell stack), the high-voltage distribution box 25 and the step-down DC 23 respectively feed back working status signals to the VCU vehicle controller 22 through the CAN network, and the VCU vehicle controller is used to issue control instructions;

[0057] The power battery system, the battery stack, the supercapacitor, the motor and the step-down DC converter are respectively connected to the voltage output end of the high-voltage distribution box;

[0058] One end of the supercapacitor bidirectional DC converter is connected to the voltage input end of the supercapacitor, and the other end is connected to the voltage output end of the high-voltage distribution box;

[0059] The motor controller is arranged on the motor, and the motor controller is used as a component of the fuel cell vehicle to send a motor working status signal;

[0060] The output end of the step-down DC converter charges the vehicle battery.

[0061] Embodiment three, as Figure 3 , is a flow chart of an active discharge strategy for a hydrogen-powered vehicle of the present invention, and its control process is as follows;

[0062] S1: The vehicle enters the power-off process;

[0063] S2: VCU sends a supercapacitor bidirectional DC off command, and the supercapacitor bidirectional DC feedback off state is off; VCU sends a battery stack shutdown command, and the battery stack feedback state is off; VCU sends a motor controller off command, and the motor controller feedback off state is off; VCU sends a step-down DC off command, and the step-down DC feedback off state is off, that is, shut down all high-voltage electrical equipment;

[0064] S3: VCU determines whether the total current monitored by the high-voltage distribution box is less than the power-off threshold of 10A. If so, it sends a power contactor disconnection command. Otherwise, it waits for the total current to drop below 10A to ensure that no arc is drawn when the contactor is disconnected, causing contactor sintering.

[0065] S4: After receiving the power contactor disconnection instruction sent by the VCU, the power battery system disconnects the power contactor and sends a signal that the power contactor is disconnected;

[0066] S5: After receiving the information that the power contactor is disconnected, the VCU sends an active discharge command and a step-down DC wave start command. After receiving the active discharge command and the step-down DC wave start command, the step-down DC turns off the undervoltage detection so that during active discharge, the voltage of the step-down DC bus will not falsely report a fault. At the same time, the wave is turned on. At this time, the step-down DC discharges the power of the pre-charge capacitor.

[0067] S6: At this time, the MCU sends the bus voltage at the input end of the motor controller, that is, the pre-charge capacitor voltage, in real time. Within 3S (the timing starts from the sending of the active discharge command), when the VCU receives the real-time bus voltage of the motor controller input end sent by the MCU <60V, it considers that the active discharge is successful, and sends the step-down DC off-wave command and the discharge completion status command;

[0068] S7: The step-down DC feedback off-wave state is off-wave, and the active discharge process is completed;

[0069] S61: If after 3S (the timing starts from the sending of the active discharge command), the VCU receives the real-time bus voltage of the motor controller input terminal sent by the MCU>60V, it is considered that the active discharge has failed, and a step-down DC off-wave instruction and a discharge failure status instruction are sent;

[0070] S71: The step-down DC feedback off-wave state is off-wave, and the active discharge process is completed;

[0071] The traditional discharge method is to release the electricity of the pre-charged capacitor through the motor controller and the motor in the form of winding heating during the power-off process, which not only wastes energy, but also may cause the motor to rotate and cause the vehicle to shake.

[0072] The embodiment of the present invention utilizes stepped-down DC to output the energy contained in the pre-charged capacitor to the vehicle battery, thereby achieving the discharge of the pre-charged capacitor and storing the capacitor charge in the vehicle battery, thus avoiding energy waste and the risk of causing the motor to rotate and cause the vehicle to shake.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

[0074] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

Claims

1. A hydrogen car active discharge circuit, characterized in that: include: A power supply module, a PDU high-voltage power distribution and pre-charging module and a pre-charging capacitor module, wherein the power supply module, the PDU high-voltage power distribution and pre-charging module and the pre-charging capacitor module are connected in series in sequence to form a discharge circuit; The power module comprises a power contactor, a first power battery and a second power battery connected in series, the first power battery and the second power battery provide energy for the fuel cell vehicle, and the power contactor is used to shut down the circuit; The PDU high voltage power distribution and pre-charging module includes: A pre-charging resistor, a main pre-charging contactor, a hydrogen fuel pre-charging contactor and an auxiliary pre-charging contactor, wherein the input end of the pre-charging resistor is connected to the output end of the power module; The output end of the pre-charging resistor is respectively connected to the input end of the main pre-charging contactor, the hydrogen fuel pre-charging contactor and the auxiliary pre-charging contactor; The main pre-filling contactor, the hydrogen fuel pre-filling contactor and the auxiliary pre-filling contactor are connected in parallel; One end of the main contactor is connected to the output end of the power module, the main contactor and the main pre-charge contactor are connected in parallel to form a first loop, and the output end of the first loop is connected to the input end of the pre-charge capacitor module; One end of the hydrogen fuel contactor is connected to the output end of the power module, the hydrogen fuel pre-charge contactor is connected in parallel with the hydrogen fuel contactor to form a second loop, and the output end of the second loop is connected to the input end of the pre-charge capacitor module; One end of the auxiliary contactor is connected to the output end of the power module, the auxiliary contactor is connected in parallel with the main contactor to form a third loop, and the output end of the third loop is connected to the input end of the pre-charge capacitor module; The first circuit, the second circuit and the third circuit are respectively connected in series with a first insurance, a second insurance and a third insurance; The output ends of the first fuse, the second fuse and the third fuse are respectively connected to the input end of the pre-charge capacitor module; The pre-charge capacitor module comprises: A drive motor system, wherein the input end of the drive motor system is connected to the output end of the first fuse, the output end of the drive motor system is connected to the input end of the power module, a fourth fuse and a supercapacitor bidirectional DC converter are connected in series, and the input end of the first fuse is connected to the output end of the main pre-charge contactor, and the output end of the supercapacitor bidirectional DC converter is connected to the input end of the power module; A stack air compression system, wherein the input end of the stack air compression system is connected to the output end of the second fuse, the output end of the stack air compression system is connected to the input end of the power module, a fifth fuse is connected in series with the stack boost DC converter, and the input end of the fifth fuse is connected to the output end of the hydrogen fuel pre-filling contactor; An air-conditioning compressor module, wherein the input end of the air-conditioning compressor module is connected to the output end of the third insurance, the output end of the air-conditioning compressor module is connected to the input end of the power module, the sixth insurance and the step-down DC converter are connected in series, and the input end of the sixth insurance is connected to the output end of the auxiliary pre-charging contactor, and the output end of the step-down DC converter is connected to the input end of the power module; The supercapacitor bidirectional DC converter, the drive motor system, the battery stack boost DC converter, the battery stack air compression system, the buck DC converter and the air conditioning compressor module are respectively connected in parallel with a pre-charge capacitor.

2. A hydrogen-powered vehicle active discharge system, comprising a vehicle controller, a supercapacitor, a supercapacitor bidirectional DC converter, a battery stack, a high-voltage distribution box, a step-down DC converter, a motor controller, a motor, a vehicle battery and a power battery system, characterized in that: The hydrogen energy vehicle active discharge system is equipped with a hydrogen energy vehicle active discharge circuit as claimed in claim 1: The power battery system, the supercapacitor, the battery stack, the high-voltage distribution box and the step-down DC converter respectively feed back working status signals to the vehicle controller through the CAN bus network, and the vehicle controller is used to issue control instructions; The power battery system, the battery stack, the supercapacitor, the motor and the step-down DC converter are respectively connected to the voltage output end of the high-voltage distribution box; One end of the supercapacitor bidirectional DC converter is connected to the voltage input end of the supercapacitor, and the other end is connected to the voltage output end of the high-voltage distribution box; The motor controller is arranged on the motor, and the motor controller is used as a component of the fuel cell vehicle to send a motor working status signal; The output end of the step-down DC converter charges the vehicle battery.

3. A hydrogen car active discharge strategy, characterized in that: The active discharge system for a hydrogen-powered vehicle as claimed in claim 2 is used to implement the active discharge strategy for the hydrogen-powered vehicle when in operation, comprising: Send a shutdown command to shut down the supercapacitor bidirectional DC converter, battery stack and motor controller; When the total current of the high-voltage distribution box is less than the power-off threshold, the power contactor is disconnected; Send active discharge command and step-down DC converter start-up command; The step-down DC converter turns off the undervoltage detection and starts the wave, and discharges the power of the pre-charge capacitor.

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