New energy electric system high voltage pre-charging box

Abstract

The utility model discloses a new energy electric system high pressure pre -filling box, include: PCB circuit board is provided with high pressure sampling module, CAN module and MCU control module, PCB circuit board parallels with pre -filling resistance, main relay respectively, be used for with the connection of several high voltage connectors and several low voltage connectors of external device. The utility model discloses through digital isolator, control circuit and drive circuit carry out electrical isolation, realize the isolation of digital domain and power domain, realize the contact collection of isolation simultaneously, directly use the high low voltage circuit connector of original car, and original car equipment circuit and software need not do any change, and realize motor controller pre -filling function, and the vehicle adaptation degree is high.

Description

Technical Field

[0001] This utility model belongs to the field of pre-charging technology, specifically a high-voltage pre-charging box for a new energy electric system. Background Technology

[0002] Currently, many new energy vehicles or equipment do not have a pre-charging circuit reserved for the superstructure or newly added electric system during the overall chassis design. However, the motor controller of the superstructure or newly added electric system is equipped with a large capacitor. This capacitor needs to be charged when the equipment is powered on; otherwise, the entire system will malfunction. However, when the high-voltage system starts, the initial resistance of the capacitive load, such as the bus capacitor in the motor controller, is extremely low. If energized directly, it will generate a short-circuit instantaneous current, which may burn out critical components such as relays and fuses.

[0003] Early motor controllers often used optocouplers or transformers for pre-charge functions, which resulted in problems such as a large number of components, large signal delays, and low reliability. For example, the electronic protection circuit provided by Chinese patent CN109842097A uses optocouplers for electrical isolation during pre-charge, which results in large signal delays and low reliability.

[0004] Other existing solutions, such as the electric vehicle pre-charging device and pre-charging method provided by Chinese patent CN105871026A, include: a pre-charging branch connected in parallel across the main relay; and a pre-charging auxiliary device connected to the positive and negative terminals of the DC bus, which further includes an electronic control unit, a bidirectional DC / DC converter circuit, and an energy storage capacitor. These solutions require modification of the original vehicle interface and the addition of control circuits to match the isolation module and pre-charging circuit. They rely on modifications to the original vehicle circuitry, increasing system costs and maintenance difficulty, and have low compatibility with different vehicles. Utility Model Content

[0005] The purpose of this utility model is to provide a high-voltage precharge box for a new energy electric system, which solves at least one aspect of the technical problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A high-voltage precharge box for a new energy electric system includes:

[0008] The PCB circuit board is equipped with a high-voltage sampling module, a CAN module, and an MCU control module.

[0009] The PCB circuit board is connected in parallel with the pre-charge resistor and the main relay, respectively.

[0010] Several high-voltage connectors and several low-voltage connectors for connecting to external devices.

[0011] As a further improvement of this utility model, the high-voltage sampling module includes several resistors and isolation operational amplifier chips.

[0012] As a further improvement of this utility model: the high-voltage sampling module is used to divide the voltage to obtain a low voltage and to perform voltage acquisition and isolation operation.

[0013] In the high-voltage sampling module, the resistor is used for voltage division. The resistor is packaged in a large size to cope with high voltage. The high-voltage signal is reduced proportionally to a low-voltage range suitable for subsequent processing. High-voltage acquisition is performed at the front and back ends of the pre-charge resistor, while the isolation operational amplifier chip is responsible for isolating and amplifying the signal to ensure safe signal transmission.

[0014] An isolation operational amplifier (OPA) is a combination of a digital isolator and an operational amplifier. It is used to safely transmit analog signals in high-voltage environments and achieve electrical isolation. In new energy vehicles, it is mainly used for high-voltage current detection, isolating high-voltage systems from low-voltage control circuits, preventing interference and electric shock risks, and ensuring system safety.

[0015] As a further improvement of this invention, the CAN module is used to communicate with external devices.

[0016] A CAN module includes a CAN chip and its control circuitry.

[0017] As a further improvement of this invention: the MCU control module is used to control the high-voltage sampling module, the CAN module, and the main relay.

[0018] The MCU control module includes an MCU processor and its control circuit, which is used to control the high-voltage sampling module to perform sampling, the main relay to close, and the CAN module to communicate.

[0019] As a further improvement of this invention: the pre-charging resistor is used to slowly charge the external capacitor during the initial power-on phase of the high-voltage system, thereby limiting the magnitude of the current.

[0020] In this invention, the pre-charge resistor mainly buffers the bus capacitor of the motor controller to limit the current.

[0021] As a further improvement of this invention, the main relay is used for circuit switching control and circuit protection.

[0022] As a further improvement of this invention, the main relay is electrically isolated by a digital isolator.

[0023] The main relay controls the conduction of the high-voltage main circuit and is part of the drive circuit. It is electrically isolated from the control circuit (MCU control module) through a digital isolator. This electrical isolation achieves isolation between the digital domain and the power domain, while also enabling isolated contact acquisition.

[0024] As a further embodiment of this utility model: the external equipment includes a motor controller, a high-voltage battery, a low-voltage power supply, and a vehicle controller.

[0025] The working principle of the high-voltage precharge box for a new energy electric system provided by this utility model is as follows:

[0026] The high voltage in the high voltage battery is supplied to the pre-charging resistor inside the pre-charging box through the high voltage connector of the pre-charging box, thereby pre-charging the capacitor of the motor controller.

[0027] The low-voltage power supply provides low-voltage power to the pre-charge box through the low-voltage connector. At this time, the high-voltage power supply is still online normally. The high-voltage sampling module in the PCB circuit board starts to work and collects and compares the voltage before and after the main relay. When the voltage at the back end reaches 95% of that at the front end, the MCU control module closes the main relay to complete the high-voltage power-on, and the motor controller receives high-voltage power.

[0028] The CAN module in the precharge box feeds back the open / closed status of the main relay to the motor controller. After receiving the enable command from the vehicle controller, the motor controller combines the closed status of the main relay fed back by the precharge and then opens the transistor to enable the motor to work.

[0029] After manually turning off the low-voltage input power switch, the main relay coil is de-energized, the high-voltage circuit of the high-voltage main relay is automatically disconnected, and the high voltage is de-energized.

[0030] Compared with the prior art, the beneficial effects of this utility model are:

[0031] 1. This utility model uses a digital isolator to electrically isolate the control circuit and the drive circuit, thereby achieving isolation between the digital domain and the power domain, and simultaneously enabling isolated contact acquisition.

[0032] 2. This utility model directly uses the original vehicle's high and low voltage circuit connectors, and through internal acquisition and control, it achieves the motor controller pre-charge function without any modification to the original vehicle's equipment circuits and software, resulting in high vehicle compatibility.

[0033] 3. This utility model can automatically control the on / off state of the main relay by collecting voltage data, and can also send the information status to the motor controller via the CAN module. Attached Figure Description

[0034] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0035] Figure 1 A schematic diagram of the specific structure of a high-voltage precharge box for a new energy electric system;

[0036] Figure 2This is a schematic diagram showing the connection position of the high-voltage precharge box in a new energy electric system.

[0037] In the diagram: 11. PCB circuit board; 12. Pre-charge resistor; 13. Main relay; 14. High voltage circuit; 15. High voltage connector; 16. Low voltage connector; 17. Motor controller; 18. High voltage battery system; 19. Low voltage power supply; 20. Vehicle controller; 111. High voltage sampling module; 112. CAN module; 113. MCU control module. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present utility model and are not intended to limit the present utility model; that is, the described embodiments are only some embodiments of the present utility model, and not all embodiments. The components of the embodiments of the present utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0039] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0040] This utility model is limited only by the claims and their full scope and equivalents. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0041] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0042] Please see Figure 1 In this embodiment of the utility model, a high-voltage precharge box for a new energy electric system includes:

[0043] The PCB circuit board 11 is equipped with a high-voltage sampling module 111, a CAN module 112 and an MCU control module 113;

[0044] PCB circuit board 11 is connected in parallel with pre-charge resistor 12 and main relay 13 respectively;

[0045] Two high-voltage connectors 15 and three low-voltage connectors 16 are used for connection to external devices.

[0046] As a further improvement of this utility model, the high-voltage sampling module 111 includes five 1M ohm resistors connected in series with a 13.3K ohm resistor, and an isolation operational amplifier chip.

[0047] As a further improvement of this utility model: the high-voltage sampling module 111 is used to divide the voltage to obtain a low voltage and to collect and isolate the voltage using an operational amplifier.

[0048] In the high-voltage sampling module, the resistor is used for voltage division. The resistor is packaged in a large size to cope with high voltage. The high-voltage signal is reduced proportionally to a low-voltage range suitable for subsequent processing. High-voltage acquisition is performed at the front and back ends of the pre-charge resistor, while the isolation operational amplifier chip is responsible for isolating and amplifying the signal to ensure safe signal transmission.

[0049] In this embodiment, the high-voltage sampling module divides the voltage to obtain a low voltage of 0-1.990V, which is then isolated by an isolation operational amplifier, converted into a differential signal by the isolation operational amplifier chip, and then shaped by an operational amplifier to be converted into a single-ended 0-1.990V for voltage acquisition.

[0050] An isolation operational amplifier (OPA) is a combination of a digital isolator and an operational amplifier. It is used to safely transmit analog signals in high-voltage environments and achieve electrical isolation. In new energy vehicles, it is mainly used for high-voltage current detection, isolating high-voltage systems from low-voltage control circuits, preventing interference and electric shock risks, and ensuring system safety.

[0051] As a further improvement of this utility model, the CAN module 112 is used to communicate with external devices.

[0052] The CAN module includes a CAN chip and its control circuit. The CAN (Controller Area Network) chip is the interface device between the CAN bus protocol controller and the physical bus. It includes a transceiver and an isolation module, which realizes the physical layer protocol conversion of CAN bus communication and ensures stable data transmission in the vehicle network.

[0053] As a further improvement of this utility model, the MCU control module 113 is used to control the high-voltage sampling module 111, the CAN module 112, and the main relay 13.

[0054] The MCU control module includes an MCU processor and its control circuit, which is used to control the high-voltage sampling module to perform sampling, the main relay to close, and the CAN module to communicate.

[0055] As a further improvement of this utility model, the pre-charging resistor 12 is used to slowly charge the external capacitor during the initial power-on phase of the high-voltage system, thereby limiting the magnitude of the current.

[0056] In this invention, the pre-charge resistor mainly buffers the bus capacitor of the motor controller to limit the current.

[0057] As a further improvement of this utility model, the main relay 13 is used for circuit switching control and circuit protection.

[0058] As a further improvement of this utility model, the main relay 13 is electrically isolated by a digital isolator.

[0059] The main relay controls the conduction of the high-voltage main circuit and is part of the drive circuit. It is electrically isolated from the control circuit (MCU control module) through a digital isolator. This electrical isolation achieves isolation between the digital domain and the power domain, while also enabling isolated contact acquisition.

[0060] In this embodiment, the main relay is driven by a 28V power supply, and the control circuit and the drive circuit are electrically isolated by a digital isolator CA-IS3742LW to achieve isolation between the digital domain and the power domain, while also enabling isolated contact acquisition.

[0061] As a further embodiment of this utility model, the external equipment includes a motor controller, a high-voltage battery, a low-voltage power supply, and a vehicle controller.

[0062] In this embodiment, the connection position when the present invention is connected to an external device is as follows: Figure 2 As shown.

[0063] The motor controller is an electronic device that drives and controls the motor of an electric vehicle. It includes a power module, control algorithm, and communication interface. It converts the DC power used by the battery into three-phase AC power to drive the motor and regulates the motor speed and torque.

[0064] The vehicle controller is the central control unit of an electric vehicle, coordinating modules such as the powertrain system, battery management system, and body control.

[0065] The working principle of the high-voltage precharge box for a new energy electric system provided by this utility model is as follows:

[0066] The high voltage in the high voltage battery is supplied to the pre-charging resistor inside the pre-charging box through the high voltage connector of the pre-charging box, thereby pre-charging the capacitor of the motor controller.

[0067] The low-voltage power supply provides low-voltage power to the pre-charge box through the low-voltage connector. At this time, the high-voltage power supply is still online normally. The high-voltage sampling module in the PCB circuit board starts to work and collects and compares the voltage before and after the main relay. When the voltage at the back end reaches 95% of that at the front end, the MCU control module closes the main relay to complete the high-voltage power-on, and the motor controller receives high-voltage power.

[0068] The CAN module in the precharge box feeds back the open / closed status of the main relay to the motor controller. After receiving the enable command from the vehicle controller, the motor controller combines the closed status of the main relay fed back by the precharge and then opens the transistor to enable the motor to work.

[0069] After manually turning off the low-voltage input power switch, the main relay coil is de-energized, the high-voltage circuit of the high-voltage main relay is automatically disconnected, and the high voltage is de-energized.

[0070] The above description is merely an example and illustration of the structure of this utility model. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the structure of the utility model or exceed the scope defined in the claims, they should all fall within the protection scope of this utility model.

Claims

1. A high-voltage pre-charge box for a new energy electric system, characterized in that, include: The PCB circuit board (11) is equipped with a high-voltage sampling module (111), a CAN module (112) and an MCU control module (113); The PCB circuit board (11) is connected in parallel with the pre-charge resistor (12) and the main relay (13); Several high-voltage connectors (15) and several low-voltage connectors (16) are used for connection to external devices.

2. The high-voltage pre-charge box for a new energy electric system according to claim 1, characterized in that, The high-voltage sampling module (111) includes several resistors and isolation operational amplifier chips.

3. The high-voltage pre-charge box for a new energy electric system according to claim 2, characterized in that, The high-voltage sampling module (111) is used to divide the voltage to obtain a low voltage and to collect and isolate the voltage.

4. The high-voltage pre-charge box for a new energy electric system according to claim 1, characterized in that, The CAN module (112) is used to communicate with external devices.

5. The high-voltage pre-charge box for a new energy electric system according to claim 1, characterized in that, The MCU control module (113) is used to control the high-voltage sampling module (111), the CAN module (112), and the main relay (13).

6. The high-voltage pre-charge box for a new energy electric system according to claim 1, characterized in that, The pre-charge resistor (12) is used to slowly charge the external capacitor during the initial power-on phase of the high-voltage system, thus limiting the current magnitude.

7. The high-voltage pre-charge box for a new energy electric system according to claim 1, characterized in that, The main relay (13) is used for circuit switching control and circuit protection.

8. A high-voltage pre-charge box for a new energy electric system according to claim 7, characterized in that, The main relay (13) is electrically isolated by a digital isolator.

9. A high-voltage pre-charge box for a new energy electric system according to claim 1, characterized in that, The external devices include a motor controller, a high-voltage battery, a low-voltage power supply, and a vehicle controller.

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