Charging control device and electric drive system of vehicle comprising the same

Abstract

The utility model relates to a kind of charging control device based on vehicle electric drive system, and vehicle electric drive system comprising the device.The device includes first relay, relay drive circuit, microcontroller and signal detection circuit.First relay is set to connect the center tap of motor to external charging pile;Microcontroller is configured to send enable signal to the relay drive circuit;Relay drive circuit is configured to control the conduction and disconnection of first relay according to the enable signal sent by microcontroller;Signal detection circuit is configured to detect the electric signal in the charging control device.The microcontroller is further configured to issue emergency instructions when the electric signal received from the signal detection circuit exceeds the set threshold.The charging control device of the utility model not only meets the charging needs of high-voltage battery pack, can adapt to different charging voltage conditions, but also improves the safety of the circuit through the redundant circuit monitoring mechanism.

Description

Technical Field

[0001] This utility model relates to the field of charging control of vehicle battery packs, and more specifically, to a charging control device based on a vehicle electric drive system, and a vehicle electric drive system including the device. Background Technology

[0002] With the rapid development of electric vehicle technology, especially the rise of high-voltage and fast-charging technologies, higher demands are being placed on the charging function of vehicle electric drive systems. For example, as battery pack voltage levels increase (e.g., from 400V to 800V), using mainstream 400V charging stations can no longer meet the charging efficiency and safety requirements of higher voltage battery packs.

[0003] To charge an 800V vehicle battery pack using a standard 400V charging station, a voltage boost is required inside the vehicle, specifically by using a BOOST circuit to increase the input voltage from 400V to 800V. This voltage conversion function is one of the key technologies for achieving fast charging, and therefore typically requires the inclusion of a relay with BOOST functionality within the vehicle.

[0004] However, during the charging process, especially in high-voltage charging scenarios, the false triggering or malfunction of the relay may lead to serious safety hazards, and in severe cases, damage the battery pack or the vehicle's electric drive system. Utility Model Content

[0005] This invention proposes a charging control device based on a vehicle electric drive system. The vehicle electric drive system includes a motor and a motor inverter. The motor inverter includes at least one voltage conversion device disposed between the motor and the vehicle's battery pack. The charging control device includes a first relay, a relay drive circuit, a microcontroller, and a signal detection circuit.

[0006] The first relay is configured to connect the center tap of the motor to an external charging pile, so as to perform a boost or buck operation on the DC power of the external charging pile by means of at least one voltage conversion device inside the motor inverter.

[0007] The microcontroller is configured to send an enable signal to the relay drive circuit;

[0008] The relay drive circuit is configured to control the on and off of the first relay according to the enable signal sent by the microcontroller; and

[0009] The signal detection circuit is configured to detect the electrical signals in the charging control device and transmit the detection results to the microcontroller.

[0010] The microcontroller is further configured to issue an emergency command when the electrical signal received from the signal detection circuit exceeds a set threshold, so that the charging control device can perform corresponding safety protection measures.

[0011] According to an optional embodiment, the relay drive circuit adopts a bridge circuit structure, and the electrical signal includes the high-side voltage value and the low-side current value in the bridge circuit.

[0012] According to an optional embodiment, the safety protection measures include disconnecting the first relay and putting the motor inverter into a corresponding safety protection state.

[0013] According to an optional embodiment, a safety monitoring module is integrated inside the relay drive circuit. The safety monitoring module is configured to monitor the operating status of the relay drive circuit in real time and transmit the monitoring results to the microcontroller. The microcontroller is configured to control the on and off of the first relay based on the electrical signal received from the signal detection circuit and the operating status received from the safety monitoring module.

[0014] According to an optional embodiment, the microcontroller is further configured to disconnect the first relay when the safety monitoring module detects an overvoltage, overcurrent, or overtemperature condition in the relay drive circuit.

[0015] According to an optional embodiment, the charging control device further includes a second relay configured to connect an external charging station directly to the vehicle's battery pack.

[0016] According to an optional embodiment, the at least one voltage conversion device includes a DC-DC boost converter, and the microcontroller is further configured to turn on a first relay and turn off a second relay when the charging voltage from the external charging pile is lower than the operating voltage of the battery pack, so as to perform a boost operation on the charging voltage from the external charging pile using the DC-DC boost converter.

[0017] According to an optional embodiment, the microcontroller is further configured to turn on the second relay and turn off the first relay when the charging voltage from the external charging pile is equal to the operating voltage of the battery pack, so as to directly use the charging voltage from the external charging pile to charge the battery pack.

[0018] This utility model also proposes a vehicle electric drive system, including a motor and a motor inverter, wherein the motor inverter includes at least one voltage conversion device disposed between the motor and the vehicle's battery pack, and the system further includes the charging control device as described above.

[0019] This utility model's charging control device, employing a relay design with BOOST function, not only meets the charging requirements of high-voltage battery packs and adapts to different charging voltage conditions, but also enhances circuit safety through redundant circuit monitoring mechanisms. This charging control device boasts excellent flexibility and compatibility, adapting to external charging piles of different voltage levels, reducing reliance on dedicated high-voltage charging piles, and providing a more reliable solution for electric vehicle charging. Compared to conventional charging control devices, this utility model's charging control device offers advantages including: efficient isolation function, ensuring circuit safety and stability during charging; redundant current and voltage monitoring functions, enabling real-time monitoring of charging status, optimizing charging efficiency, and preventing potential faults; and a design that meets functional safety requirements, significantly improving system reliability and safety through multiple protection mechanisms, providing comprehensive protection for the electric vehicle charging process. Attached Figure Description

[0020] By incorporating the figures in this article and subsequently the accompanying figures Figure 1 The specific embodiments used to illustrate certain principles of this utility model will make other features and advantages of the method of this utility model clearer or more specifically explained.

[0021] Figure 1 An internal structural diagram of a charging control device based on a vehicle electric drive system according to an exemplary embodiment of the present invention is shown.

[0022] Figure 2 It shows Figure 1 The diagram shows the working principle of the charging control device.

[0023] Figure 3 It shows Figure 1 The diagram shows the signal transmission process of the charging control device during operation. Detailed Implementation

[0024] The charging control device based on a vehicle electric drive system according to the present invention will now be described with reference to the accompanying drawings and embodiments. In the following description, numerous specific details are set forth to enable those skilled in the art to gain a more complete understanding of the present invention. However, it will be apparent to those skilled in the art that implementations of the present invention may not include some of these specific details. Instead, the present invention may be conceived to be practiced with any combination of the following features and elements, regardless of whether they relate to different embodiments. Therefore, the following aspects, features, embodiments, and advantages are for illustrative purposes only and should not be construed as elements or limitations of the claims.

[0025] In the electric drive system of electric vehicles, a relay charging circuit with boost function is added inside the vehicle to boost the lower voltage from the external charging station to the higher voltage required by the battery pack. Typically, the positive terminal of this charging circuit is drawn from the center tap of the motor, reusing the boost converter circuit inside the motor inverter. However, this design has potential risks. For example, in motor drive mode, if the relay mis-triggers, it can adversely affect the motor inverter, or even damage the inverter or other critical components, thus affecting the normal operation of the vehicle.

[0026] In existing relay charging circuits with boost functionality, the switching of the relay is typically controlled by a standard driver chip, lacking comprehensive voltage and current monitoring capabilities and failing to monitor voltage and current changes in the driver chip in real time during charging. Furthermore, with the introduction of the ISO 26262 functional safety standard in China, the functional safety architecture of electric vehicles needs to meet higher ASIL (Autonomous Safety Indicators) requirements. However, the design of existing relay charging circuits with boost functionality fails to adequately consider these standards and lacks safety mechanisms to meet the corresponding ASIL levels.

[0027] Against this backdrop, this invention proposes a charging control device based on a vehicle electric drive system. Using this charging control device, during normal charging, the charging voltage from the charging pile directly charges the battery pack via a conventional relay. However, when the charging voltage is insufficient to meet the battery pack's needs, a separate, additionally designed relay is used for boost charging. Furthermore, this charging control device also features redundant detection functionality for the relay drive circuit. By designing redundant voltage / current monitoring paths and corresponding safety protection mechanisms, it is possible to effectively prevent the relay from erroneously triggering under abnormal conditions.

[0028] Figure 1 An internal structural diagram of a charging control device based on a vehicle electric drive system according to an exemplary embodiment of the present invention is shown. This vehicle electric drive system is mainly used in electric vehicles and includes a motor M and a motor inverter, the motor inverter being disposed between the motor M and the vehicle battery pack. The motor inverter includes at least one voltage conversion device, such as a DC-DC boost converter, for voltage conversion between the motor and the battery pack.

[0029] The core of this charging control device lies in enabling the boosting or bucking of the DC power from the external charging station to meet the charging needs of the battery pack, while ensuring the functional safety and reliability of the charging process. To achieve this, the charging control device includes core components such as a first relay, a relay drive circuit, a microcontroller (MCU), and a signal detection circuit.

[0030] exist Figure 1The circuit diagram shows a negative relay H and a positive relay A. For simplicity, the first relay in this document will primarily refer to "positive relay A," which is designed to connect the motor's center tap to an external charging station. This connection allows the DC power from the external charging station to be boosted or bucked via a voltage converter within the motor inverter, thus adapting to the battery pack's operating voltage requirements.

[0031] The microcontroller, as the control core of the entire system, is responsible for sending enable signals to the relay drive circuit. Upon receiving the enable signal, the relay drive circuit can correspondingly control the on and off states of the first relay, thereby achieving precise control over the battery pack charging process.

[0032] The signal detection circuit is responsible for real-time detection of electrical signals in the charging control device, including parameters such as voltage and current, and transmits the detection results to the microcontroller. The microcontroller analyzes the received electrical signals according to preset thresholds. Once the detected electrical signal exceeds the set safety threshold, the microcontroller immediately issues an emergency command to trigger corresponding safety protection measures. These measures may include disconnecting the first relay to cut off the charging circuit, or putting the motor inverter into a corresponding safety protection state (e.g., ASC state) to prevent overvoltage, overcurrent, or other faults from damaging components in the circuit.

[0033] In this embodiment, the relay drive circuit is designed to use a bridge circuit structure. The high-side voltage and low-side current values ​​of the bridge circuit are monitored in real time by the signal detection circuit and fed back to the microcontroller to ensure the stability and safety of the charging process.

[0034] To further enhance circuit safety, a safety monitoring module is integrated within the relay drive circuit. This module can monitor the operating status of the relay drive circuit in real time, detecting conditions such as overvoltage, overcurrent, or overtemperature. The monitoring results are also transmitted to the microcontroller, enabling it to make redundant judgments based on the dual information received from the signal detection circuit and the safety monitoring module, thus providing more comprehensive control over the relay's on / off state. For example, when the safety monitoring module detects overvoltage, overcurrent, or overtemperature in the relay drive circuit, the microcontroller will immediately disconnect the first relay to protect the entire system from damage.

[0035] In addition, the charging control device in this embodiment also includes a second relay, which can directly connect an external charging pile to the vehicle's battery pack. Figure 1The diagram shows that the second relay includes a positive relay B and a negative relay C. For simplicity, in this document, the second relay mainly refers to "positive relay B". When the charging voltage of the external charging station matches the operating voltage of the battery pack, the microcontroller controls the second relay to be turned on while the first relay is turned off, thereby directly using the charging voltage of the external charging station to charge the battery pack, thus improving charging efficiency and avoiding unnecessary energy conversion losses. When the charging voltage of the external charging station is lower than the operating voltage of the battery pack, the microcontroller controls the first relay to be turned on and the second relay to be turned off, so as to use the DC-DC boost converter inside the motor inverter to boost the charging voltage of the external charging station, thereby ensuring that the battery pack can obtain an appropriate charging voltage.

[0036] Figure 2 It shows Figure 1 The diagram below illustrates the working principle of the charging control device. (Refer to the diagram below.) Figure 2 The following describes the operation of the charging control device. First, when boost charging of the battery pack is required, the microcontroller (MCU) sends an enable signal to the relay drive circuit and simultaneously sends a control signal to activate the voltage / current detection circuit, ensuring that the drive circuit and detection circuit can start working. The relay drive circuit then performs the on / off operation of the relay based on the received enable signal. Furthermore, the relay drive circuit has an internal safety monitoring module (e.g., overvoltage, overcurrent, and overtemperature monitoring modules), which, together with the external signal (voltage / current) detection circuit, allows the detection results to be further transmitted to the MCU to determine whether voltage or current exceeds limits.

[0037] In summary, this charging control device features two redundant protection paths. One path uses an internal safety monitoring module within the drive circuit to detect anomalies such as overvoltage, overcurrent, or overtemperature, and sends an interrupt output to the relay to cut off the relay. The other path uses an external signal detection circuit to detect overvoltage or overcurrent in the charging path, and the MCU's logic control circuit puts the entire system (especially the motor inverter) into a safe protection state. This redundant protection mechanism enables the vehicle charging system to achieve ASIL B / C safety level.

[0038] Figure 3 It shows Figure 1The diagram illustrates the signal transmission process of the charging control device during operation. During the boost charging of the battery pack, the MCU enables the relay drive circuit (bridge circuit structure) to operate, controlling the relay to conduct. At this time, the relay drive circuit can drive the relay through a corresponding high-side switch and a low-side switch in its bridge circuit, achieving the purpose of closing the relay. Simultaneously, the relay drive circuit automatically collects the low-side current value, which is then transmitted to the MCU after internal signal conversion. On the other hand, the MCU also directly detects the high-side voltage value of the relay drive circuit (i.e., the voltage value after boosting) using an external signal detection circuit, thereby detecting whether the relay drive circuit is performing the correct driving function. If the voltage or current exceeds the threshold, the MCU will issue a corresponding emergency command to put the motor controller into a safety protection state or directly disconnect the relay.

[0039] In this article, "high-side voltage" refers to the voltage value of the upper arm (high-side) of the bridge circuit structure, which is connected to the positive terminal of the input power supply. It is typically the voltage relative to ground (GND) and reflects the level of the input voltage when the bridge circuit is switched on. "Low-side current" refers to the current value flowing through the lower arm (low-side) of the bridge circuit. The low-side current value reflects the magnitude of the current when the low-side switch is turned on.

[0040] This utility model's charging control device, through the adoption of a relay design with BOOST function, not only meets the charging requirements of high-voltage battery packs and adapts to different charging voltage conditions, but also improves circuit safety through a redundant circuit monitoring mechanism. This charging control device possesses good flexibility and compatibility, adapting to external charging piles of different voltage levels, reducing reliance on dedicated high-voltage charging piles, and providing a more reliable solution for the charging process of electric vehicles.

[0041] Another embodiment of this utility model relates to a vehicle electric drive system, which mainly includes a motor, a motor inverter, and a battery pack. The motor inverter integrates a voltage conversion device to adjust the voltage output of the battery pack according to different operating conditions, ensuring efficient motor operation. Furthermore, the electric drive system also integrates a charging control device according to this utility model, which uses the voltage conversion device to perform boost or buck operations on the voltage of the external charging station, thereby matching the battery pack's needs and achieving efficient charging. This charging control device has multiple safety protection functions, capable of real-time monitoring of parameters such as voltage and current during the charging process, and quickly taking safety measures when an abnormality is detected, such as disconnecting the circuit or entering a protection state, to ensure the safety and reliability of the vehicle's charging and driving processes.

[0042] In this invention, the term "connection" refers to "electrical connection" or "communication connection." Furthermore, terms such as "comprising" and "including" indicate that, in addition to the elements directly and explicitly stated in the specification and claims, the technical solution of this application does not exclude the presence of other elements not directly or explicitly stated.

[0043] In this utility model, those skilled in the art will understand that the disclosed system can be implemented in other ways. The system implementation methods described above are merely illustrative. For example, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, the functions of multiple modules can be combined, or the function of a certain module can be further split. In the various embodiments of this utility model, each module can be integrated into one processing unit, or each module can exist physically separately, or two or more modules can be integrated into one unit.

[0044] Although the present invention has been disclosed above with reference to preferred embodiments, it is not limited thereto. All modifications and alterations made without departing from the spirit and scope of the present invention should be included within its protection scope. Therefore, the protection scope of the present invention should be determined by the scope defined in the claims.

Claims

1. A charging control device based on a vehicle electric drive system, the vehicle electric drive system including a motor and a motor inverter, the motor inverter including at least one voltage conversion device disposed between the motor and the vehicle's battery pack, characterized in that, The charging control device includes a first relay, a relay driving circuit, a microcontroller, and a signal detection circuit, wherein... The first relay is configured to connect the center tap of the motor to an external charging pile, so as to perform a boost or buck operation on the DC power of the external charging pile by means of at least one voltage conversion device inside the motor inverter. The microcontroller is configured to send an enable signal to the relay drive circuit; The relay drive circuit is configured to control the on and off of the first relay according to the enable signal sent by the microcontroller; and The signal detection circuit is configured to detect the electrical signals in the charging control device and transmit the detection results to the microcontroller. The microcontroller is further configured to issue an emergency command when the electrical signal received from the signal detection circuit exceeds a set threshold, so that the charging control device can perform corresponding safety protection measures.

2. The charging control device according to claim 1, characterized in that, The relay drive circuit adopts a bridge circuit structure, and the electrical signal includes the high-side voltage value and the low-side current value in the bridge circuit.

3. The charging control device according to claim 1 or 2, characterized in that, The safety protection measures include disconnecting the first relay and putting the motor inverter into the corresponding safety protection state.

4. The charging control device according to claim 1 or 2, characterized in that, A safety monitoring module is integrated inside the relay drive circuit. The safety monitoring module is configured to monitor the operating status of the relay drive circuit in real time and transmit the monitoring results to the microcontroller. The microcontroller is configured to control the conduction and disconnection of the first relay based on the electrical signal received from the signal detection circuit and the operating status received from the safety monitoring module.

5. The charging control device according to claim 4, characterized in that, The microcontroller is further configured to disconnect the first relay when the safety monitoring module detects an overvoltage, overcurrent, or overtemperature condition in the relay drive circuit.

6. The charging control device according to claim 1 or 2, characterized in that, The charging control device also includes a second relay configured to connect an external charging station directly to the vehicle's battery pack.

7. The charging control device according to claim 6, characterized in that, The at least one voltage conversion device includes a DC-DC boost converter, and the microcontroller is further configured to turn on a first relay and turn off a second relay when the charging voltage from the external charging pile is lower than the operating voltage of the battery pack, so as to perform a boost operation on the charging voltage from the external charging pile using the DC-DC boost converter.

8. The charging control device according to claim 6, characterized in that, The microcontroller is further configured to turn on the second relay and turn off the first relay when the charging voltage from the external charging pile is equal to the operating voltage of the battery pack, so as to directly use the charging voltage from the external charging pile to charge the battery pack.

9. A vehicle electric drive system, comprising a motor and a motor inverter, the motor inverter including at least one voltage conversion device disposed between the motor and a battery pack of the vehicle, characterized in that, The vehicle electric drive system also includes a charging control device according to any one of claims 1 to 8.

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