Circuit for preventing power-on error sequence of high-voltage box

Abstract

The utility model discloses a circuit for preventing the power-on wrong sequence of a high-voltage box, and the circuit comprises a battery pack which is provided with a battery positive electrode and a battery negative electrode; the PCS energy storage converter is provided with a positive electrode and a negative electrode, the positive electrode of the PCS energy storage converter is connected with the battery positive electrode of the battery pack, and the negative electrode of the PCS energy storage converter is connected with the battery negative electrode of the battery pack; the isolating switch is connected between the PCS energy storage converter and the battery pack; and the BMS main board is electrically connected with the isolating switch and is used for monitoring the on-off condition of the isolating switch. On and off of the disconnecting switch are monitored through the BMS main board, and pre-charging is performed after the disconnecting switch is closed, so that the current is prevented from being too large.

Description

Technical Field

[0001] This utility model relates to the field of high-voltage box power supply circuit technology, and in particular to a circuit for preventing incorrect power supply sequence in high-voltage boxes. Background Technology

[0002] The original circuit's normal operating procedure was to first close the isolating switch, and then the BMS mainboard would control the battery to precharge the PCS. However, in the original circuit, the precharging and isolating switch were not linked, which meant that precharging might end before the isolating switch was closed. In this case, closing the isolating switch again could result in excessive current, which was extremely dangerous. Based on this, a circuit was designed to prevent incorrect power-on sequence to the high-voltage box. Utility Model Content

[0003] To overcome at least one of the defects described in the prior art, this utility model provides a circuit to prevent incorrect power sequence in a high-voltage box. The circuit monitors the closing and opening of the isolating switch via the BMS mainboard, and pre-charging only occurs after the isolating switch is closed to avoid excessive current.

[0004] The technical solution adopted by this utility model to solve its problem is:

[0005] A circuit for preventing incorrect power sequence in a high-voltage box includes: a battery pack having a positive and a negative terminal; a PCS energy storage converter having a positive and a negative terminal, the positive terminal of which is connected to the positive terminal of the battery pack, and the negative terminal of which is connected to the negative terminal of the battery pack; a disconnecting switch connected between the PCS energy storage converter and the battery pack; and a BMS mainboard electrically connected to the disconnecting switch for monitoring the opening and closing status of the disconnecting switch.

[0006] By adopting the above solution, it can be ensured that the connection between the battery pack and the PCS energy storage converter can be reliably disconnected when needed, ensuring personnel safety and preventing the escalation of the fault; at the same time, the status of the isolating switch can be confirmed before the system is powered on, avoiding misoperation, ensuring the correct power-on sequence, and preventing circuit faults caused by abnormal connections.

[0007] Furthermore, a shunt is connected between the negative terminal of the PCS energy storage converter and the negative terminal of the battery pack, and the shunt is electrically connected to the BMS mainboard.

[0008] By adopting the above solution, the charging and discharging current of the battery pack can be monitored in real time. The BMS mainboard calculates the battery charging and discharging capacity and assesses the battery health status based on this current data. It can also detect abnormalities such as overcurrent in a timely manner, triggering protection mechanisms to prevent damage to the battery and circuit components due to abnormal current.

[0009] Furthermore, a negative contactor is connected between the negative terminal of the PCS energy storage converter and the negative terminal of the battery pack, and the negative contactor is electrically connected to the BMS mainboard.

[0010] By adopting the above scheme, the BMS can precisely control the closing and opening of the negative contactor. During system power-on and power-off processes, it can connect or disconnect the battery pack negative terminal from the PCS energy storage converter in the correct sequence; in case of a fault, it can quickly disconnect the negative circuit to ensure circuit safety and avoid electrical accidents caused by abnormal negative connection.

[0011] Furthermore, a positive contactor is connected between the positive terminal of the PCS energy storage converter and the positive terminal of the battery pack, and the positive contactor is electrically connected to the BMS mainboard.

[0012] By adopting the above scheme, the positive contactor is connected to the BMS mainboard, enabling the BMS to effectively control the connection and disconnection between the battery pack's positive terminal and the PCS energy storage converter. Combined with the negative contactor, precise control of the battery's main circuit can be achieved, ensuring that the circuit is sequentially connected when power is applied and reliably disconnected when power is lost. When overvoltage, overcurrent, or other faults are detected, the positive circuit can be quickly disconnected to prevent the fault from escalating and protect the battery and other equipment.

[0013] Furthermore, a fuse is connected between the positive terminal of the PCS energy storage converter and the positive terminal of the battery pack.

[0014] By adopting the above solution, when a short circuit or other overcurrent fault occurs in the circuit, the fuse element melts quickly, cutting off the circuit and preventing excessive current from causing permanent damage to the battery pack, PCS energy storage converter, etc., thus providing reliable short circuit protection.

[0015] Furthermore, a pre-charge contactor is provided between the positive terminal of the PCS energy storage converter and the positive terminal of the battery pack, and in parallel with the positive terminal contactor. The pre-charge contactor is electrically connected to the BMS mainboard.

[0016] By adopting the above scheme, the pre-charge contactor is electrically connected to the BMS main board and in parallel with the positive contactor. When the system is powered on, the BMS first controls the pre-charge contactor to close, and pre-charges the capacitive load in the PCS energy storage converter through the pre-charge resistor to avoid large current surges. After the pre-charge is completed, the BMS controls the positive contactor to close, and then disconnects the pre-charge contactor to ensure a safe and stable power-on process and protect circuit components.

[0017] Furthermore, a pre-charge resistor is connected between the positive terminal of the PCS energy storage converter and the positive terminal of the battery pack, and the pre-charge resistor is connected in series with the pre-charge contactor.

[0018] By adopting the above scheme, the pre-charging resistor is connected in series with the pre-charging contactor to limit the current during the pre-charging process, keep the pre-charging current within a safe range, and avoid excessive surge current caused by direct charging of the capacitive load of the PCS energy storage converter. Attached Figure Description

[0019] Figure 1 This is a circuit diagram of an embodiment of the present utility model;

[0020] The meanings of the reference numerals in the attached diagram are as follows: 11. Battery positive terminal; 12. Battery negative terminal; 2. PCS energy storage converter; 3. Disconnecting switch; 4. BMS main board; 5. Shunt; 6. Negative contactor; 7. Positive contactor; 8. Fuse; 9. Precharge contactor; 10. Precharge resistor. Detailed Implementation

[0021] To better understand and implement this invention, the technical solutions in the embodiments of this invention will be clearly and completely described and discussed below with reference to the accompanying drawings. Obviously, what is described here is only a part of the examples of this invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the protection scope of this invention.

[0022] To facilitate understanding of the embodiments of this utility model, further explanations and descriptions will be provided below with reference to the accompanying drawings and specific embodiments. These embodiments do not constitute a limitation on the embodiments of this utility model.

[0023] In the description of this utility model, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0025] See Figure 1This utility model discloses a circuit for preventing incorrect power-on sequence in a high-voltage box: it includes a battery pack, a PCS energy storage converter 2, a disconnecting switch 3, and a BMS mainboard 4. The battery pack has a positive terminal 11 and a negative terminal 12. The PCS energy storage converter 2 has a positive terminal and a negative terminal. The positive terminal of the PCS energy storage converter 2 is connected to the positive terminal 11 of the battery pack, and the negative terminal of the PCS energy storage converter 2 is connected to the negative terminal 12 of the battery pack. The disconnecting switch 3 is connected between the PCS energy storage converter 2 and the battery pack. The BMS mainboard 4 is electrically connected to the disconnecting switch 3 and is used to monitor the opening and closing status of the disconnecting switch 3. This ensures that the connection between the battery pack and the PCS energy storage converter can be reliably disconnected when needed, ensuring personnel safety and preventing the escalation of faults. Simultaneously, it allows confirmation of the status of the disconnecting switch 3 before system power-on, avoiding misoperation, ensuring the correct power-on sequence, and preventing circuit faults caused by abnormal connections.

[0026] The BMS motherboard 4 has a total voltage sampling device, which has a BAT+ interface and a BAT- interface. The BAT+ interface is connected between the positive terminal of the PCS energy storage converter 2 and the positive terminal 11 of the battery pack, and the BAT- interface is connected between the negative terminal of the PCS energy storage converter 2 and the negative terminal 12 of the battery pack.

[0027] A shunt 5 is connected between the negative terminal of the PCS energy storage converter 2 and the negative terminal 12 of the battery pack. The shunt 5 is electrically connected to the BMS mainboard 4 and can monitor the charging and discharging current of the battery pack in real time. The BMS mainboard calculates the battery charging and discharging capacity and assesses the battery health status based on this current data. It can also detect abnormalities such as overcurrent in a timely manner, triggering a protection mechanism to prevent damage to the battery and circuit components due to abnormal current. Specifically, the BMS mainboard 4 is equipped with a shunt 5 sampling device. The shunt 5 sampling device has a C+ interface and a C- interface, and the C+ interface and the C- interface are connected to the shunt 5.

[0028] A negative contactor 6 connects the negative terminal of the PCS energy storage converter 2 to the negative terminal 12 of the battery pack. The negative contactor 6 is electrically connected to the BMS mainboard 4, and the BMS can precisely control the closing and opening of the negative contactor 6. During system power-on and power-off processes, it can connect or disconnect the battery pack negative terminal from the PCS energy storage converter in the correct sequence. In case of a fault, it can quickly disconnect the negative circuit to ensure circuit safety and avoid electrical accidents caused by abnormal negative connection. Specifically, the BMS mainboard 4 is equipped with a negative contactor 6 coil driver, which has a first PMR+ interface and an RLY2 interface, both of which are electrically connected to the negative contactor 6.

[0029] A positive contactor 7 is connected between the positive terminal of the PCS energy storage converter 2 and the positive terminal 11 of the battery pack. The positive contactor 7 is electrically connected to the BMS mainboard 4, enabling the BMS to effectively control the connection and disconnection between the positive terminal of the battery pack and the PCS energy storage converter. In conjunction with the negative contactor 6, precise control of the battery main circuit is achieved, ensuring sequential circuit connection upon power-up and reliable circuit disconnection upon power-off. When overvoltage or overcurrent faults are detected, the positive circuit can be quickly disconnected to prevent the fault from escalating and protect the battery and other equipment. Specifically, the BMS mainboard 4 is equipped with a positive contactor 7 coil driver, which has a second PWR+ interface and an RLY1 interface, both electrically connected to the positive contactor 7.

[0030] A fuse 8 is connected between the positive terminal of the PCS energy storage converter 2 and the positive terminal 11 of the battery pack. When a short circuit or other overcurrent fault occurs in the circuit, the fuse 8 melts quickly, cutting off the circuit and preventing excessive current from causing permanent damage to the battery pack, PCS energy storage converter, etc., thus providing reliable short circuit protection.

[0031] A pre-charge contactor 9 is provided between the positive terminal of the PCS energy storage converter 2 and the positive terminal 11 of the battery pack, and in parallel with the positive contactor 7. The pre-charge contactor 9 is electrically connected to the BMS mainboard 4. When the system is powered on, the BMS first controls the pre-charge contactor 9 to close, pre-charging the capacitive load in the PCS energy storage converter through the pre-charge resistor 10 to avoid large current surges. After pre-charging is complete, the BMS controls the positive contactor 7 to close, and then disconnects the pre-charge contactor 9 to ensure a safe and stable power-on process and protect circuit components. Specifically, the BMS mainboard 4 is provided with a pre-charge contactor 9 coil driver, which has a third PWR+ interface and an RLY3 interface, both of which are electrically connected to the pre-charge contactor 9. A pre-charging resistor 10 is connected between the positive terminal of the PCS energy storage converter 2 and the positive terminal 11 of the battery pack. The pre-charging resistor 10 is connected in series with the pre-charging contactor 9. During the pre-charging process, the current is limited and the pre-charging current is controlled within a safe range to avoid excessive surge current caused by direct charging of the capacitive load of the PCS energy storage converter.

[0032] The disconnecting switch 3 is connected between the positive terminal of the PCS energy storage converter 2 and the positive terminal 11 of the battery pack, and between the negative terminal of the PCS energy storage converter 2 and the negative terminal 12 of the battery pack. The BMS mainboard 4 is equipped with a contact feedback monitoring system, which has a PWR- interface and an IO+ interface. The PWR- interface and the IO+ interface are electrically connected to the disconnecting switch 3. The IO+ interface of the BMS mainboard 4 is used to detect the closing and opening of this contact. Related logic is added to the software of the BMS mainboard 4; pre-charging will only begin after the contact is detected to be closed, i.e., after the disconnecting switch 3 is closed.

[0033] By adding hardware detection and software logic judgment to the isolating switch 3, this invention can basically eliminate the situation where pre-charging occurs when the isolating switch 3 is not closed, thereby greatly increasing the safety of the equipment during use.

[0034] The technical means disclosed in this utility model are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this utility model, and these improvements and modifications are also considered within the scope of protection of this utility model.

Claims

1. A circuit for preventing incorrect power sequence in a high-voltage box, characterized in that, include: A battery pack having a positive terminal and a negative terminal; PCS energy storage converter, wherein the PCS energy storage converter has a positive terminal and a negative terminal, the positive terminal of the PCS energy storage converter is connected to the positive terminal of the battery pack, and the negative terminal of the PCS energy storage converter is connected to the negative terminal of the battery pack. A disconnecting switch, which is connected between the PCS energy storage converter and the battery pack; The BMS mainboard is electrically connected to the disconnect switch and is used to monitor the opening and closing status of the disconnect switch.

2. The circuit for preventing power-on mistiming of a high voltage tank according to claim 1, wherein A shunt is connected between the negative terminal of the PCS energy storage converter and the negative terminal of the battery pack, and the shunt is electrically connected to the BMS mainboard.

3. The circuit for preventing power-on mistiming of a high voltage tank according to claim 1, wherein A negative contactor is connected between the negative terminal of the PCS energy storage converter and the negative terminal of the battery pack, and the negative contactor is electrically connected to the BMS mainboard.

4. The circuit for preventing power-on mistiming of a high voltage tank according to claim 1, wherein A positive contactor is connected between the positive terminal of the PCS energy storage converter and the positive terminal of the battery pack, and the positive contactor is electrically connected to the BMS mainboard.

5. The circuit for preventing power-on-missequencing of a high voltage cabinet of claim 1, wherein, A fuse is connected between the positive terminal of the PCS energy storage converter and the positive terminal of the battery pack.

6. The circuit for preventing power-on-missequencing of a high voltage cabinet of claim 4, wherein, A pre-charge contactor is provided between the positive terminal of the PCS energy storage converter and the positive terminal of the battery pack, and in parallel with the positive terminal contactor. The pre-charge contactor is electrically connected to the BMS main board.

7. The circuit for preventing power-on-missequencing of a high voltage cabinet of claim 6, wherein, A pre-charge resistor is connected between the positive terminal of the PCS energy storage converter and the positive terminal of the battery pack, and the pre-charge resistor is connected in series with the pre-charge contactor.

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