Auxiliary charging device for railway vehicle

Abstract

The utility model relates to the technical field of railway vehicle charging, in particular to an auxiliary charging device for railway vehicles, which comprises a transformer, a charger, an inverter and a battery management unit, the transformer is used for converting high-voltage alternating current of a power grid into alternating current adaptive to the charger, the charger converts the alternating current into direct current, and the inverter is used for converting the direct current into direct current. The inverter is used for converting direct current of the storage battery into alternating current, and the alternating current is used by vehicle-mounted auxiliary equipment; the battery management unit is used for monitoring and managing the state of the storage battery, and the state of the storage battery comprises voltage, current and temperature. The utility model solves the problems of low charging efficiency and incomplete battery management of the current auxiliary charging device.

Description

Technical Field

[0001] The utility model relates to the technical field of rail vehicle charging, in particular to an auxiliary charging device for rail vehicles. Background Art

[0002] The auxiliary charging device of a rail vehicle is used to provide power to the auxiliary equipment and batteries on the vehicle when the vehicle is stationary or running at low load.

[0003] The current auxiliary charging device still has the following problems:

[0004] Low charging efficiency: Traditional charging methods often fail to fully utilize the power of the power grid, resulting in low charging efficiency and increased energy consumption.

[0005] Poor battery management: Lack of effective battery status monitoring and management mechanisms may lead to overcharging or discharging of batteries, shortening battery life.

[0006] Heat dissipation problem: The charger generates a lot of heat when running at high power. If there is no effective heat dissipation measure, it will affect the stability and life of the equipment.

[0007] To address the above issues, how to achieve a highly efficient charging process through advanced power electronic conversion technology and intelligent battery management systems while ensuring the health of the battery and extending its service life is a challenge in the current design of auxiliary charging devices for rail vehicles. Utility Model Content

[0008] The utility model provides an auxiliary charging device for rail vehicles, which solves the problems of low charging efficiency and imperfect battery management of current auxiliary charging devices.

[0009] In order to achieve the purpose of the present utility model, the technical solution adopted is: an auxiliary charging device for rail vehicles, including a transformer, a charger, an inverter and a battery management unit, the transformer is used to convert the high-voltage AC power of the power grid into AC power suitable for use by the charger, the charger converts the AC power into DC power to charge the battery on the rail vehicle, and the inverter is used to convert the DC power of the battery into AC power for use by on-board auxiliary equipment; the battery management unit is used to monitor and manage the status of the battery, which includes voltage, current and temperature.

[0010] As an optimized solution of the present invention, the battery management unit includes a microcontroller, which is an STM32F single-chip microcomputer.

[0011] As an optimization solution of the present invention, the battery management unit also includes a voltage acquisition circuit, which includes a resistor R101, a resistor R108, a diode D15, a diode D14, a bidirectional breakdown diode D16, a capacitor C126, a bidirectional breakdown diode D17, a diode D19, a diode D18, a capacitor C125, a capacitor C124, a resistor R105, a resistor R112, a capacitor C129, a resistor R106, a capacitor C127 and an amplifier U15, wherein the resistor R101 is connected to the positive input terminal of the amplifier U15, the resistor R108 is connected to the negative input terminal of the amplifier U15, the diode D15 is connected between the positive input terminal of the amplifier U15 and the positive power supply voltage, and the diode D14 is connected to the positive pole of the amplifier U15. Input terminal and negative power supply voltage, bidirectional breakdown diode D16 is connected between the positive input terminal of amplifier U15 and ground, bidirectional breakdown diode D17 is connected between the negative input terminal of amplifier U15 and ground, diode D19 is connected between the negative input terminal of amplifier U15 and the negative power supply voltage, diode D18 is connected between the negative input terminal of amplifier U15 and the positive power supply voltage, capacitor C125 and capacitor C126 are connected in parallel between the negative input terminal and the positive input terminal of amplifier U15, resistor R112 and capacitor C129 are connected in parallel between the negative input terminal and the output terminal of amplifier U15, resistor R106 is connected between the output terminal of amplifier U15 and UDC1 terminal, and capacitor C127 is connected between UDC1 terminal and ground.

[0012] As an optimization solution of the present invention, the battery management unit also includes a current acquisition circuit, which includes a resistor R117, a resistor R130, a resistor R135, a capacitor C139, an amplifier U14, a resistor R136, a resistor R134, a resistor R131, a resistor R118, a resistor R121, a diode D21, a diode D20 and a capacitor C138. The resistor R117 is connected to the positive input terminal of the amplifier U14, and the resistor R130 and the resistor R135 are connected in series to the positive input terminal of the amplifier U14. and ground, capacitor C139 is connected between the positive input terminal of amplifier U14 and ground, resistor R136 is connected between the negative input terminal of amplifier U14 and ground, resistor R134 and resistor R131 are connected in series between the negative input terminal of amplifier U14 and the output terminal of amplifier U14, resistor R118 and resistor R121 are connected in series between the output terminal of amplifier U14 and IDC3 terminal, diode D21 and diode D20 are connected in series between the power supply and ground, and capacitor C138 is connected between IDC3 terminal and ground.

[0013] As an optimized solution of the present invention, the battery management unit further includes a temperature acquisition circuit, which acquires the temperature of the single battery pack and the battery box through an NTC thermistor.

[0014] As an optimized solution of the present invention, the charger includes a rectifier unit, a PFC circuit, a filter circuit, and a DCDC converter. The rectifier unit is used to convert AC power into DC power. The PFC circuit is used to improve the efficiency of the charger in drawing power from the power grid. The filter circuit is connected between the rectifier unit and the PFC circuit. The DCDC converter is used to convert coarse-tuned DC power into DC power suitable for battery charging.

[0015] As an optimized solution of the present invention, the filtering circuit is an LC filtering network.

[0016] As an optimization solution of the present invention, the auxiliary charging device for rail vehicles also includes a heat dissipation system, which is used to keep the charger running within a suitable temperature range. The heat dissipation system is a heat sink, a fan or a liquid cooling system.

[0017] The utility model has positive effects:

[0018] 1) The utility model introduces a PFC circuit (power factor correction circuit), which significantly improves the efficiency of the charger in absorbing electric energy from the power grid, reduces harmonic pollution to the power grid, and improves energy utilization.

[0019] 2) The use of the DCDC converter of the present invention ensures that the charger can convert the coarse-tuned DC power into DC power that is precisely suitable for charging the battery, thereby optimizing the charging process and improving the charging efficiency.

[0020] 3) This utility model utilizes intelligent battery management: Utilizing an advanced battery management unit (BMS), it integrates real-time monitoring of voltage, current, and temperature, ensuring safe and efficient battery operation and extending battery life. The use of a microcontroller enables intelligent battery status analysis and control strategies, improving system response speed and accuracy.

[0021] 4) The utility model provides stable power supply: the configuration of the inverter enables the battery to provide stable AC power to the on-board auxiliary equipment when the vehicle is running at low load or at rest, thereby enhancing the self-sufficiency of the vehicle.

[0022] 5) Comprehensive thermal management of the utility model: The introduction of the heat dissipation system effectively controls the temperature of the charger, ensures that the power electronic components operate within an appropriate temperature range, and improves the stability and reliability of the system.

[0023] 6) System integration and optimization of the utility model: Through the design and optimized combination of key components such as transformers, chargers, inverters, battery management units and heat dissipation systems, the utility model realizes efficient, intelligent and stable operation of the auxiliary charging system for rail vehicles, improves overall performance and reduces costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0025] Figure 1 This is a schematic block diagram of the overall principle of the utility model;

[0026] Figure 2 This is a schematic block diagram of the charger principle of the utility model;

[0027] Figure 3 This is a schematic diagram of the circuit principle of the microcontroller of the utility model;

[0028] Figure 4 This is a schematic diagram of the circuit principle of the voltage acquisition circuit of the utility model;

[0029] Figure 5 It is a circuit principle diagram of the current acquisition circuit of the utility model.

[0030] Among them: 1. Transformer, 2. Charger, 3. Inverter, 4. Battery Management Unit, 21. Rectifier Unit, 22. PFC Circuit, 23. Filter Circuit, 24. DCDC Converter. DETAILED DESCRIPTION

[0031] like Figure 1 As shown, the present invention discloses an auxiliary charging device for rail vehicles, comprising a transformer 1, a charger 2, an inverter 3, and a battery management unit 4. The transformer 1 is used to convert high-voltage AC power from the power grid into AC power suitable for use by the charger 2. The charger 2 converts the AC power into DC power to charge the batteries on the rail vehicle. The inverter 3 is used to convert the DC power of the battery into AC power for use by onboard auxiliary equipment. The battery management unit 4 is used to monitor and manage the battery status, including voltage, current, and temperature. The transformer 1 is used to adjust the voltage level, and may be used to convert high-voltage AC power from the power grid into lower-voltage AC power suitable for use by the charger.

[0032] like Figure 2 As shown, the charger 2 includes a rectifier unit 21, a PFC circuit 22, a filter circuit 23, and a DCDC converter 24. The rectifier unit 21 is used to convert AC power into DC power. The PFC circuit 22 is used to improve the efficiency of the charger 2 in drawing power from the power grid. The filter circuit 23 is connected between the rectifier unit 21 and the PFC circuit 22. The DCDC converter 24 is used to convert the coarse-tuned DC power into DC power suitable for battery charging.

[0033] Rectifier unit 21: The rectifier unit is the first-stage converter of the charger, and its main task is to convert alternating current (AC) obtained from the power grid into direct current (DC).

[0034] PFC Circuit 22: The PFC circuit (Power Factor Correction Circuit) primarily improves the efficiency with which the charger draws power from the grid. By controlling the current waveform to match the voltage waveform, the PFC circuit significantly improves the power factor, making the charger more efficient and environmentally friendly. By adjusting the current waveform to improve the power factor, it also reduces harmonic interference with the grid.

[0035] Filter circuit 23: Located between rectifier unit 21 and PFC circuit 22, filter circuit 23 further smoothes the DC waveform, removing any residual AC components and ripple from the rectification process, providing a purer DC input for subsequent circuits. Filter circuit 23 is an LC filter network.

[0036] DCDC converter 24: The DCDC converter receives filtered DC power and converts it into a more finely regulated and stable DC power to meet the battery charging requirements. DCDC converters can use a variety of topologies, such as Buck (step-down), Boost (step-up), Buck-Boost (step-up / step-down), or Cuk converters.

[0037] like Figure 3 As shown, the battery management unit 4 includes a microcontroller, which is an STM32F single-chip microcomputer, specifically STM32F103RCT6.

[0038] like Figure 4As shown, the battery management unit 4 also includes a voltage acquisition circuit, which includes a resistor R101, a resistor R108, a diode D15, a diode D14, a bidirectional breakdown diode D16, a capacitor C126, a bidirectional breakdown diode D17, a diode D19, a diode D18, a capacitor C125, a capacitor C124, a resistor R105, a resistor R112, a capacitor C129, a resistor R106, a capacitor C127 and an amplifier U15, wherein the resistor R101 is connected to the positive input terminal of the amplifier U15, the resistor R108 is connected to the negative input terminal of the amplifier U15, the diode D15 is connected between the positive input terminal of the amplifier U15 and the positive power supply voltage, and the diode D14 is connected between the positive input terminal of the amplifier U15 and the negative The power supply voltage is connected between the positive input terminal of amplifier U15 and ground, the bidirectional breakdown diode D16 is connected between the positive input terminal of amplifier U15 and ground, the bidirectional breakdown diode D17 is connected between the negative input terminal of amplifier U15 and ground, the diode D19 is connected between the negative input terminal of amplifier U15 and the negative power supply voltage, the diode D18 is connected between the negative input terminal of amplifier U15 and the positive power supply voltage, the capacitor C125 and the capacitor C126 are connected in parallel between the negative input terminal and the positive input terminal of amplifier U15, the resistor R112 and the capacitor C129 are connected in parallel between the negative input terminal and the output terminal of amplifier U15, the resistor R106 is connected between the output terminal of amplifier U15 and the UDC1 terminal, and the capacitor C127 is connected between the UDC1 terminal and ground. The voltage acquisition circuit is a sampling circuit diagram for sampling the battery voltage through a differential circuit. Similarly, to protect the microcontroller, the input value range should be kept between 0 and 3V and should be limited before input.

[0039] like Figure 5As shown, the battery management unit 4 also includes a current acquisition circuit, which includes a resistor R117, a resistor R130, a resistor R135, a capacitor C139, an amplifier U14, a resistor R136, a resistor R134, a resistor R131, a resistor R118, a resistor R121, a diode D21, a diode D20 and a capacitor C138. The resistor R117 is connected to the positive input terminal of the amplifier U14, and the resistor R130 and the resistor R135 are connected in series between the positive input terminal of the amplifier U14 and the ground. Capacitor C139 is connected between the positive input of amplifier U14 and ground, resistor R136 is connected between the negative input of amplifier U14 and ground, resistors R134 and R131 are connected in series between the negative input of amplifier U14 and the output of amplifier U14, resistors R118 and R121 are connected in series between the output of amplifier U14 and IDC3, diodes D21 and D20 are connected in series between the power supply and ground, and capacitor C138 is connected between IDC3 and ground. Current measurement uses a differential circuit, but it's important to note that batteries operate in two operating modes, charging and discharging, in practice, and current flows in two directions. Voltage signals can also be positive or negative due to the different directions of battery charge and discharge current. Therefore, to measure current, the voltage level at negative potentials must be raised above zero. This is done by using an external voltage source to raise the potential. Current measurement is achieved by converting the current signal into a voltage signal and limiting it.

[0040] The battery management unit 4 also includes a temperature acquisition circuit that uses an NTC thermistor to collect the temperature of the battery pack and the battery box. The NTC thermistor has a negative temperature coefficient, and the relationship between its resistance and temperature is shown in the following equation:

[0041]

[0042] Where T represents the absolute temperature at the time of measurement, R is the resistance of the NTC thermistor at absolute temperature T, R0 is the resistance of the NTC thermistor at absolute temperature T0 (T0 = 298.15K), and B is the thermal sensitivity index, which is related to the material used to make the thermistor. The temperature acquisition result is directly converted to a digital value by the STM32 microcontroller's internal A / D converter and then obtained through linear interpolation.

[0043] Voltage: By continuously monitoring the voltage of each battery cell or the entire battery pack, the battery management unit can promptly detect abnormal conditions and take appropriate protective measures, such as stopping the charging and discharging process to avoid battery damage.

[0044] Current: The battery management unit can control the charge and discharge rate by monitoring the current, ensuring that the battery operates within a safe range and avoiding overcharging or over-discharging.

[0045] Temperature: The battery management unit monitors the battery temperature in real time and can activate the cooling or heating system when necessary to maintain the battery temperature within an ideal range to ensure the battery's optimal working condition.

[0046] The battery management unit collects this data, analyzes and processes it through a microcontroller (such as an STM32F MCU), and intelligently controls the battery's charging and discharging processes. Furthermore, the battery management unit communicates with the charger and inverter to share battery status information, enabling coordinated operation of the entire auxiliary charging system. In this way, the battery management unit ensures the efficient and safe operation of the battery in the auxiliary charging system.

[0047] The auxiliary charging device for rail vehicles also includes a heat dissipation system, which is used to keep the charger running within a suitable temperature range. The heat dissipation system is a heat sink, a fan or a liquid cooling system.

[0048] In an auxiliary charging device, the cooling system's primary purpose is to quickly and effectively remove heat generated by the charger, ensuring it operates within its optimal operating temperature range, thereby improving efficiency, extending its lifespan, and ensuring safety. The effectiveness of the cooling system directly impacts the performance of the charger and the reliability of the entire auxiliary charging device.

[0049] A heat sink is a passive cooling method that increases heat exchange efficiency by increasing surface area, dissipating heat from the charger into the air. Heat sinks are typically made of materials with good thermal conductivity (such as aluminum or copper) and are mounted directly on the heating element, without the need for an additional power source.

[0050] Fans: Fans can be installed inside or outside the charger to help dissipate heat by drawing in cool air or expelling hot air. Fans generally provide better cooling than relying solely on natural convection, but may require more consideration in terms of noise control and maintenance.

[0051] Liquid cooling system: It removes heat by circulating liquid (such as water or special coolant), which can achieve very uniform and efficient heat exchange.

[0052] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An auxiliary charging device for a rail vehicle, characterized in that: The invention comprises a transformer (1), a charger (2), an inverter (3) and a battery management unit (4); the transformer (1) is used to convert high-voltage alternating current (AC) of a power grid into AC power suitable for use by the charger (2); the charger (2) converts the AC power into DC power to charge batteries on rail vehicles; the inverter (3) is used to convert the DC power of the battery into AC power for use by onboard auxiliary equipment; and the battery management unit (4) is used to monitor and manage the state of the battery, which includes voltage, current and temperature.

2. The auxiliary charging device for a rail vehicle according to claim 1, characterized in that: The battery management unit (4) comprises a microcontroller, which is an STM32F single-chip microcomputer.

3. The auxiliary charging device for a rail vehicle according to claim 1, characterized in that: The battery management unit (4) further comprises a voltage acquisition circuit, which comprises a resistor R101, a resistor R108, a diode D15, a diode D14, a bidirectional breakdown diode D16, a capacitor C126, a bidirectional breakdown diode D17, a diode D19, a diode D18, a capacitor C125, a capacitor C124, a resistor R105, a resistor R112, a capacitor C129, a resistor R106, a capacitor C127 and an amplifier U15, wherein the resistor R101 is connected to the positive input terminal of the amplifier U15, the resistor R108 is connected to the negative input terminal of the amplifier U15, the diode D15 is connected between the positive input terminal of the amplifier U15 and the positive power supply voltage, and the diode D14 is connected between the positive input terminal of the amplifier U15 and the negative power supply voltage. negative power supply voltage, a bidirectional breakdown diode D16 is connected between the positive input terminal of the amplifier U15 and ground, a bidirectional breakdown diode D17 is connected between the negative input terminal of the amplifier U15 and ground, a diode D19 is connected between the negative input terminal of the amplifier U15 and the negative power supply voltage, a diode D18 is connected between the negative input terminal of the amplifier U15 and the positive power supply voltage, a capacitor C125 and a capacitor C126 are connected in parallel between the negative input terminal and the positive input terminal of the amplifier U15, a resistor R112 and a capacitor C129 are connected in parallel between the negative input terminal and the output terminal of the amplifier U15, a resistor R106 is connected between the output terminal of the amplifier U15 and the UDC1 terminal, and a capacitor C127 is connected between the UDC1 terminal and ground.

4. The auxiliary charging device for a rail vehicle according to claim 3, characterized in that: The battery management unit (4) further includes a current acquisition circuit, which includes a resistor R117, a resistor R130, a resistor R135, a capacitor C139, an amplifier U14, a resistor R136, a resistor R134, a resistor R131, a resistor R118, a resistor R121, a diode D21, a diode D20 and a capacitor C138, wherein the resistor R117 is connected to the positive input terminal of the amplifier U14, and the resistor R130 and the resistor R135 are connected in series between the positive input terminal of the amplifier U14 and the ground. , capacitor C139 is connected between the positive input terminal of amplifier U14 and ground, resistor R136 is connected between the negative input terminal of amplifier U14 and ground, resistor R134 and resistor R131 are connected in series between the negative input terminal of amplifier U14 and the output terminal of amplifier U14, resistor R118 and resistor R121 are connected in series between the output terminal of amplifier U14 and IDC3 terminal, diode D21 and diode D20 are connected in series between the power supply and ground, and capacitor C138 is connected between IDC3 terminal and ground.

5. The auxiliary charging device for a rail vehicle according to claim 4, characterized in that: The battery management unit (4) further comprises a temperature acquisition circuit, which acquires the temperature of the single battery pack and the temperature of the battery box via an NTC thermistor.

6. The auxiliary charging device for a rail vehicle according to claim 5, characterized in that: The charger (2) comprises a rectifier unit (21), a PFC circuit (22), a filter circuit (23), and a DC-DC converter (24). The rectifier unit (21) is used to convert alternating current into direct current. The PFC circuit (22) is used to improve the efficiency of the charger (2) in absorbing electric energy from a power grid. The filter circuit (23) is connected between the rectifier unit (21) and the PFC circuit (22). The DC-DC converter (24) is used to convert coarsely regulated direct current into direct current suitable for charging a battery.

7. The auxiliary charging device for a rail vehicle according to claim 6, characterized in that: The filtering circuit (23) is an LC filtering network.

8. The auxiliary charging device for a rail vehicle according to claim 7, characterized in that: The auxiliary charging device for rail vehicles also includes a heat dissipation system, which is used to keep the charger (2) running within a suitable temperature range. The heat dissipation system (6) is a heat sink, a fan or a liquid cooling system.

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