Super capacitor assembly on mobile charging vehicle and application method thereof

Abstract

The invention discloses a super capacitor assembly on a mobile charging vehicle and an application method thereof, and relates to the technical field of mobile charging vehicles. The super capacitor assembly comprises a high-voltage energy storage battery, a power supply conversion module, a low-voltage driving loop, a super capacitor and a relay. According to the super-capacitor assembly on the mobile charging vehicle and the application method of the super-capacitor assembly, a DCDC is adopted in a power supply system, a high-voltage energy storage battery mounted on the mobile charging vehicle is subjected to voltage reduction to supply power to a driving system, a super-capacitor is connected into the driving system in parallel, and feedback current of a motor is absorbed through the super-capacitor; the problems of high cost, complex system, inconvenience in use and the like caused by adopting a high-voltage small-power motor or adding a small-capacity medium-low voltage battery in a mobile charging vehicle are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of mobile charging vehicles, and in particular to a supercapacitor component on a mobile charging vehicle and an application method thereof. Background Art

[0002] The existing mobile charging vehicles need to charge new energy vehicles, and the charging batteries they carry are large-capacity high-voltage batteries. Therefore, the vehicle's own movement requires a high-voltage power supply as the power supply for its own drive system. The mobile charging vehicles have low speeds, and the motors used in the drive system are mostly low-power motors. High-voltage low-power motors have a small application range and high costs. In addition, the drive system cannot achieve wide voltage adaptability when equipped with charging batteries of different voltage platforms. Another solution currently uses a low-voltage drive system to convert the high-voltage power supply into the voltage power supply required by the drive system through DCDC, but because the motor has characteristics such as energy recovery, a component must absorb the feedback current.

[0003] First, in the existing technical solutions, mobile charging vehicles are limited by the supply chain resources of high-voltage and low-power motors, and most of them use medium- and low-voltage drive motors as the vehicle power source. The upper energy replenishment battery is a high-voltage platform, so the vehicle needs to be equipped with a medium- and low-voltage power battery for the drive voltage to provide power for the drive motor. In order to replenish the medium- and low-voltage power battery, a set of medium- and low-voltage power battery charging devices needs to be added to the vehicle to charge it when the medium- and low-voltage power battery is fed.

[0004] However, the cost of adding an extra set of medium and low voltage power batteries and charging devices to the chassis is high, and in actual application, the upper high voltage battery and the medium and low voltage power batteries need to be charged and replenished separately, which is inconvenient to use, and the vehicle's cruising range is limited by the power limit of the medium and low voltage power batteries. The existing technical solutions are complex, and the added medium and low voltage power batteries need to be additionally certified for transportation during vehicle transportation, which brings unnecessary certification costs. The addition of medium and low voltage power batteries to the vehicle adds unnecessary hidden dangers to the safety of the entire vehicle;

[0005] Second, in the existing technical solutions, mobile charging vehicles are limited by the supply chain resources of high-voltage and low-power motors, and most of them use medium and low voltage drive motors as the vehicle power source. The upper-mounted energy replenishment battery is a high-voltage platform, so the vehicle uses DCDC to step down the upper-mounted high-voltage power supply to power the medium and low voltage drive motors.

[0006] In the existing technical solution, the upper high-voltage power supply is stepped down through DCDC to power the drive system. However, due to the complex operating conditions of the drive system and the drastic changes in power demand, the power requirements and performance requirements of DCDC are high. The DCDC needs to have sufficient backup power during design, which greatly increases the cost, volume and heat dissipation capacity of DCDC.

[0007] In the existing technical solutions, when the medium and low voltage drive motors are in deceleration, braking, downhill and other working conditions, the drive motors are in the power generation state, and the current flow direction in the drive system loop changes from the original DCDC flowing to the motor to the motor flowing to the DCDC. The DCDC is a unidirectional step-down design, and there are no other devices in the drive system loop that can absorb the reverse current, which will cause the drive system loop voltage to rise sharply, causing the drive system to be overvoltage, there is a risk of damaging the device, and reducing the stability of the system.

[0008] Therefore, the above solution adds a small-capacity, low-voltage battery to the drive system, resulting in a waste of vehicle layout space and increased costs. In addition, the battery is greatly affected by temperature and is difficult to adapt to high and low temperature environment requirements. At the same time, there are many inconveniences in terms of safety and transportation certification. Summary of the invention

[0009] In view of the deficiencies in the prior art, the present invention provides a supercapacitor assembly on a mobile charging vehicle and an application method thereof, which solves the problems of high cost, complex system, inconvenience in use, etc. caused by using high-voltage low-power motors or adding small-capacity medium and low-voltage batteries in mobile charging vehicles.

[0010] To achieve the above objectives, the present invention is implemented through the following technical solutions: a supercapacitor assembly on a mobile charging vehicle, comprising a high-voltage energy storage battery, a power conversion module is mounted at the rear end of the high-voltage energy storage battery, the output end of the power conversion module is connected to a low-voltage drive circuit, the positive pole of the power conversion module and the low-voltage drive circuit are connected in parallel with a relay, and are connected to the common contact end of the relay, the normally open contact end of the relay is connected to a supercapacitor, and is connected to the positive pole of the supercapacitor, and the negative pole of the supercapacitor is connected in parallel with the negative pole of the power conversion module and the low-voltage drive circuit.

[0011] Preferably, the high-voltage energy storage battery is used for power storage.

[0012] Preferably, the power conversion module is used to convert a 300V-800V high-voltage power supply into a 72V power supply for use in a low-voltage drive circuit.

[0013] Preferably, the low-voltage drive circuit is used to provide power supply.

[0014] Preferably, the supercapacitor is used to store electric current.

[0015] Preferably, the relay is used to disconnect the super capacitor and the low-voltage drive circuit.

[0016] The present invention also discloses a method for applying a supercapacitor assembly on a mobile charging vehicle, comprising the following steps:

[0017] When the high-voltage energy storage battery is powered on and outputs externally, the power conversion module starts the conversion, converting the high voltage electricity of the high-voltage energy storage battery into a stable 72V DC power supply to charge the supercapacitor. After the supercapacitor is charged, the power demand of the low-voltage drive circuit is met. When the vehicle accelerates or travels at a constant speed, the current flows to the power conversion module, and then from the power conversion module to the low-voltage drive circuit. When the vehicle decelerates, travels downhill or brakes, the vehicle motor is converted to a generator state. At this time, the motor will generate a back electromotive force. At this time, the back electromotive force is greater than the output voltage of the power conversion module, generating a feedback current. The current flows from the motor to the motor controller, and then to the supercapacitor. The supercapacitor absorbs the feedback current generated by the motor power generation. At this time, the supercapacitor voltage increases slightly, suppressing the low-voltage drive. The circuit voltage rises sharply. When the vehicle resumes stable driving, the motor is no longer in the power generation state. When the supercapacitor voltage is higher than the DCDC output voltage, the current flows from the power conversion module to the low-voltage drive circuit. When the supercapacitor voltage is equal to the output voltage of the power conversion module, the current flows from the power battery to the power conversion module, and then from the power conversion module to the low-voltage drive circuit. When the vehicle is lying on a slope or crossing an obstacle, if the driving power is less than or equal to the output power of the power conversion module, the current flows from the power battery to the power conversion module, and then from the power conversion module to the low-voltage drive circuit. If the driving power is greater than the output power of the power conversion module, the current flows from the power battery to the power conversion module, and then from the power conversion module and the low-voltage drive circuit to the low-voltage drive circuit together.

[0018] The present invention provides a supercapacitor assembly on a mobile charging vehicle and an application method thereof. Compared with the prior art, it has the following beneficial effects:

[0019] 1. The supercapacitor component and application method on the mobile charging vehicle have strong adaptability to the battery voltage range, which effectively avoids the need to develop drive systems with different corresponding voltage levels due to the mobile charging vehicle being equipped with high-voltage batteries of different voltage levels. It can effectively ensure the versatility of the drive system to greatly reduce the development cost. The mobile charging vehicle produced using this solution can use the 72V drive system, which is currently in large demand and highly mature on the market, so that the stability of the drive system is effectively guaranteed.

[0020] 2. The supercapacitor component and its application method on the mobile charging vehicle effectively solves the problem that when the mobile charging vehicle is braking or going downhill, the reverse charging current generated by the motor energy recovery cannot be absorbed or is wasted, causing the drive circuit voltage to rise sharply, resulting in overvoltage, overheating faults, and burning of components.

[0021] 3. The supercapacitor component and application method on the mobile charging vehicle, when the mobile charging vehicle suddenly encounters severe working conditions, the driving power surges, and the DCDC cannot meet the driving power demand, the supercapacitor provides supplementary power supply to avoid driving undervoltage and power interruption. In addition, during the design, the DCDC does not need to have too much backup power, which reduces the design requirements for the DCDC and can reduce the cost and size of the DCDC.

[0022] 4. The supercapacitor assembly and application method on the mobile charging vehicle. The supercapacitor is a physical energy storage device, which is safe and stable, does not require transportation certification, and is more convenient for vehicles to carry out logistics transportation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a diagram of the power supply solution architecture of the present invention;

[0024] Figure 2 This is a diagram of the power-on process of the power supply system of the present invention.

[0025] In the figure: 1. High-voltage energy storage battery; 2. Power conversion module; 3. Low-voltage drive circuit; 4. Supercapacitor; 5. Relay. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] See also Figure 1-2 The embodiment of the present invention provides a technical solution: a supercapacitor assembly on a mobile charging vehicle, including a high-voltage energy storage battery 1, a power conversion module 2, a low-voltage drive circuit 3, a supercapacitor 4 and a relay 5, wherein the model of the high-voltage energy storage battery 1 is a 300V~800V high-voltage energy storage battery, the model of the power conversion module 2 is a 300~800V to 72V isolated DCDC, the low-voltage drive circuit 3 is the low-voltage electrical system of the vehicle, which is responsible for distributing the 72V voltage converted by the high-voltage energy storage battery 1 through the power conversion module 2 to various low-voltage electrical equipment of the vehicle, the model of the supercapacitor 4 is 81V12F, and the relay 5 adopts a common model on the market.

[0028] In the mobile charging vehicle, a high-voltage energy storage battery 1 is mounted on the upper body, and a power conversion module 2 is mounted at the rear end of the high-voltage energy storage battery. The output end of the power conversion module 2 is connected to a low-voltage drive circuit 3. In the power conversion module 2 and the low-voltage drive circuit 3, the positive electrode is connected in parallel to the common contact end of the relay 5, the normally open contact end of the relay 5 is connected to the positive electrode of the supercapacitor 4, and the negative electrode of the supercapacitor 4 is then connected in parallel to the power conversion module 2 and the negative electrode of the low-voltage drive circuit 3.

[0029] In this solution, the power conversion module 2 is used to convert the power into 72V power and supply it to the low-voltage drive circuit 3. If the low-voltage drive circuit 3 generates a reverse current during operation, since the power conversion module 2 only supports unidirectional current flow, the reverse current generated by the low-voltage drive circuit 3 cannot flow back to the high-voltage energy storage battery 1 through the power conversion module 2, which will cause the voltage of the low-voltage drive circuit 3 and the low-voltage drive circuit to rise rapidly, which may easily cause damage to components. Since the super capacitor 4 is connected in parallel between the power conversion module 2 and the low-voltage drive circuit 3 to absorb the reverse current, the voltage of the low-voltage drive circuit and the like is suppressed. , thereby protecting the system from damage. If the current demand of the low-voltage drive circuit 3 increases sharply, the super capacitor 4 can be used for current compensation to reduce the power supply pressure of the power conversion module 2, so as to reduce the design requirements for the power conversion module 2. Under high-load conditions, the system can still operate stably. Because the super capacitor 4 has the function of storing charge, when the vehicle is powered off, there is still voltage in the super capacitor 4. In order to completely power off the low-voltage drive circuit 3, the relay 5 can be used to disconnect the connection between the super capacitor 4 and the low-voltage drive circuit 3. After the vehicle is powered off, the power supply of the low-voltage drive circuit 3 is completely cut off.

[0030] The first application method of supercapacitors on mobile charging vehicles, the vehicle power-on logic is that when the vehicle receives a power-on request, the vehicle prioritizes low-voltage power-on. After the low-voltage power-on is completed, a power-on request is sent to the upper-mounted high-voltage energy storage battery 1. After the request is sent, it is detected whether the upper-mounted energy storage battery is discharging and outputting normally. If the high-voltage power is output normally, it is then detected whether the supercapacitor 4 has power. If the supercapacitor 4 has power, an output enable request is sent to the power conversion module 2. At this time, the power conversion module 2 pre-charges the low-voltage drive circuit 3. After the pre-charging of the low-voltage drive circuit 3 is completed, the relay 5 at the supercapacitor 4 end is closed, and the power-on is completed at this time; if there is no power in the supercapacitor 4, the relay 5 at the supercapacitor 4 end is closed first, and then an output enable request is sent to the low-voltage drive circuit 3. At this time, the low-voltage drive circuit 3 pre-charges the low-voltage drive circuit 3 and the supercapacitor 4. After the pre-charging is completed, the power-on is completed.

[0031] The second application method of supercapacitors in mobile charging vehicles is that when the vehicle is braking or driving downhill during driving, the motor is in a power generation state, the potential of the drive circuit increases, and a feedback current is generated. Due to the presence of supercapacitor 4, this part of the current flows into supercapacitor 4 for storage, and will not cause the potential of the low-voltage drive circuit 3 to rise sharply, causing overvoltage and damage to the device. When climbing or overcoming obstacles during driving, the motor power suddenly increases, and the current demanded by the low-voltage drive circuit 3 suddenly increases in a short period of time. If it exceeds the output power of the power conversion module 2, due to the presence of supercapacitor 4, the backup power is provided by supercapacitor 4, which will not cause undervoltage in the low-voltage drive circuit 3, resulting in power.

[0032] The embodiment of the present invention further provides a technical solution: a method for applying a supercapacitor assembly on a mobile charging vehicle, comprising the following steps:

[0033] When the high-voltage energy storage battery 1 is powered on and outputs externally, the power conversion module 2 starts the conversion, converting the high voltage electricity of the high-voltage energy storage battery 1 into a stable 72V DC power supply to charge the supercapacitor 4. After the supercapacitor 4 is charged, the power demand of the low-voltage drive circuit 3 is met. When the vehicle accelerates or travels at a constant speed, the current flows to the power conversion module 2, and then flows from the power conversion module 2 to the low-voltage drive circuit 3. When the vehicle decelerates, travels downhill or brakes, the vehicle motor is converted to a generator state. At this time, the motor will generate a back electromotive force. At this time, the back electromotive force is greater than the output voltage of the power conversion module 2, generating a feedback current. The current flows from the motor to the motor controller, and then flows to the supercapacitor 4. The supercapacitor 4 absorbs the feedback current generated by the motor power generation. At this time, the voltage of the supercapacitor 4 increases slightly, suppressing the low-voltage drive circuit 3. The voltage rises sharply. When the vehicle resumes stable driving, the motor is no longer in the power generation state. When the voltage of the supercapacitor 4 is higher than the output voltage of the power conversion module 2, the current flows from the power conversion module 2 to the low-voltage drive circuit 3. When the voltage of the supercapacitor 4 is equal to the output voltage of the power conversion module 2, the current flows from the power battery to the power conversion module 2, and then from the power conversion module 2 to the low-voltage drive circuit 3. When the vehicle is lying on a slope or crossing an obstacle, if the driving power is less than or equal to the output power of the power conversion module 2, the current flows from the power battery to the power conversion module 2, and then from the power conversion module 2 to the low-voltage drive circuit 3. If the driving power is greater than the output power of the power conversion module 2, the current flows from the power battery to the power conversion module 2, and then from the power conversion module 2 and the low-voltage drive circuit 3 to the low-voltage drive circuit 3 together.

[0034] By using a power conversion module 2 in the power system, the upper high-voltage energy storage battery 1 is stepped down to power the low-voltage drive circuit 3, and a super capacitor 4 is connected in parallel in the low-voltage drive circuit 3 to absorb the motor feedback current through the super capacitor 4.

[0035] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A supercapacitor assembly on a mobile charging vehicle, characterized in that: The invention comprises a high-voltage energy storage battery (1), wherein a power conversion module (2) is mounted at the rear end of the high-voltage energy storage battery (1), wherein the output end of the power conversion module (2) is connected to a low-voltage drive circuit (3), wherein the positive poles of the power conversion module (2) and the low-voltage drive circuit (3) are connected in parallel to a relay (5) and are connected to a common contact end of the relay (5), wherein the normally open contact end of the relay (5) is connected to a super capacitor (4) and is connected to the positive pole of the super capacitor (4), and wherein the negative pole of the super capacitor (4) is connected in parallel to the negative poles of the power conversion module (2) and the low-voltage drive circuit (3).

2. The supercapacitor assembly on a mobile charging vehicle according to claim 1, characterized in that: The high-voltage energy storage battery (1) is used for power storage.

3. The supercapacitor assembly on a mobile charging vehicle according to claim 1, characterized in that: The power conversion module (2) is used to convert a 300V to 800V high voltage power supply into a 72V power supply for use by a low voltage drive circuit (3).

4. The supercapacitor assembly on a mobile charging vehicle according to claim 1, characterized in that: The low-voltage drive circuit (3) is used to provide power supply.

5. The supercapacitor assembly on a mobile charging vehicle according to claim 1, characterized in that: The supercapacitor (4) is used to store electric current.

6. The supercapacitor assembly on a mobile charging vehicle according to claim 1, characterized in that: The relay (5) is used to disconnect the super capacitor (4) and the low-voltage drive circuit (3).

7. The method for applying a supercapacitor assembly on a mobile charging vehicle according to any one of claims 1 to 6, characterized in that: The following steps are involved: When the high-voltage energy storage battery (1) is powered on and outputs power to the outside, the power conversion module (2) starts conversion, converting the high voltage electricity of the high-voltage energy storage battery (1) into a stable 72V DC power supply to charge the supercapacitor (4). After the supercapacitor (4) is charged, the power demand of the low-voltage drive circuit (3) is met. When the vehicle accelerates or travels at a constant speed, the current flows to the power conversion module (2), and then flows from the power conversion module (2) to the low-voltage drive circuit (3). When the vehicle decelerates, travels downhill or brakes, the vehicle motor changes to a generator state. At this time, the motor will generate a back electromotive force. At this time, the back electromotive force is greater than the output voltage of the power conversion module (2), generating a feedback current. The current flows from the motor to the motor controller and then to the supercapacitor (4). The supercapacitor (4) absorbs the feedback current generated by the motor power generation. At this time, the voltage of the supercapacitor (4) increases slightly, suppressing the voltage of the low-voltage drive circuit (3). The voltage of the super capacitor (4) increases sharply. When the vehicle resumes stable driving, the motor is no longer in the power generation state. When the voltage of the super capacitor (4) is higher than the DCDC output voltage, the current flows from the power conversion module (2) to the low-voltage drive circuit (3). When the voltage of the super capacitor (4) is equal to the output voltage of the power conversion module (2), the current flows from the power battery to the power conversion module (2), and then from the power conversion module (2) to the low-voltage drive circuit (3). When the vehicle is in a state of lying on a slope or crossing an obstacle, if the driving power is less than or equal to the output power of the power conversion module (2), the current flows from the power battery to the power conversion module (2), and then from the power conversion module (2) to the low-voltage drive circuit (3). If the driving power is greater than the output power of the power conversion module (2), the current flows from the power battery to the power conversion module (2), and then from the power conversion module (2) and the low-voltage drive circuit (3) together to the low-voltage drive circuit (3).

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