Charging control method for multi-pack parallel battery power system

Abstract

The invention discloses a charging control method for a multi-pack parallel battery power system, and the method comprises the following steps: the battery power system comprises a plurality of battery pack assemblies, and each battery pack assembly comprises a battery pack and a two-layer BCU controller; during charging, the battery pack is connected with an international charging pile through a charging circuit, the charging circuit is provided with an on-off control module, and the charging circuit is in communication interaction with the international charging pile through a first-layer BCU controller; after the first-layer BCU controller completes charging handshake with the international charging pile, state detection is carried out on the battery pack through the second-layer BCU controller; and when the state detection result of the second-layer BCU controller on the battery pack is'fault-free ', the second-layer BCU controller sends the detection result to the first-layer BCU controller, the first-layer BCU controller sends an instruction of'charging permission' to the battery pack assembly, and the international charging pile charges the battery pack. According to the invention, the charging speed of the battery power system is greatly improved, the overall charging time is shortened, and the charging efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of charging technology, and in particular to a charging control method for a multi-pack parallel battery power system. Background Art

[0002] The battery power systems of some existing new energy vehicles (such as electric cars, electric yachts, electric vertical take-off and landing aircraft, etc.) usually adopt a parallel architecture of multiple battery packs, that is, a battery power system is formed by combining multiple independent battery packs in parallel. When charging the battery power system with the above-mentioned multi-pack parallel architecture, traditional charging piles can only charge a single battery pack in the battery power system independently at a time, and cannot charge multiple battery packs in the battery power system at the same time, which leads to the problem of long overall charging time and low charging efficiency. Summary of the invention

[0003] The purpose of the present invention is to solve the deficiencies in the prior art and provide a charging control method for a multi-pack parallel battery power system.

[0004] The object of the present invention is achieved through the following technical solution: a charging control method for a multi-pack parallel battery power system, the method is as follows: The battery power system includes several battery pack assemblies, which include battery packs and a two-layer BCU controller; When charging, the battery pack is connected to the international charging pile through the charging line. The charging line is equipped with an on-off control module, which communicates and interacts with the international charging pile through a layer of BCU controller; After the first-layer BCU controller completes the charging handshake with the international charging pile, the second-layer BCU controller detects the status of the battery pack; when the second-layer BCU controller detects the status of the battery pack as "no fault", the second-layer BCU controller sends the detection result to the first-layer BCU controller, and the first-layer BCU controller sends a "charging allowed" instruction to the battery pack assembly. The second-layer BCU controller controls the on-off control module on the battery pack assembly to close, and the international charging pile charges the battery pack.

[0005] Preferably, the charging circuit includes a first charging cable and a second charging cable, one end of the first charging cable is connected to the positive pole of the battery pack, and the other end of the first charging cable is connected to the positive charging interface on the international charging pile; one end of the second charging cable is connected to the negative pole of the battery pack, and the other end of the second charging cable is connected to the negative charging interface on the international charging pile.

[0006] Preferably, the on-off control module includes a pre-charging branch arranged on the first charging line, a pre-charging resistor and a first relay are arranged on the pre-charging branch, and the pre-charging resistor and the first relay are connected in series; a second relay is arranged on the first charging line, and the pre-charging resistor and the first relay are connected in parallel with the second relay; the on-off of the first relay and the second relay is controlled by a second-layer BCU controller; When the international charging pile charges the battery pack, the second-layer BCU controller is used to control the first relay to close and the second relay to disconnect. The charging current of the international charging pile passes through the pre-charging resistor on the pre-charging branch and pre-charges the battery pack. During the pre-charging process, the second-layer BCU controller detects the status of the battery pack. When the pre-charging time reaches the set time, the second-layer BCU controller controls the second relay to close and the first relay to disconnect. The charging current of the international charging pile charges the battery pack through the first charging line. If during the pre-charging process, the second-layer BCU controller detects that the battery pack is in a faulty state, the second-layer BCU controller controls the second relay to disconnect and sends out an alarm signal.

[0007] Preferably, during the pre-charging process, the voltage and temperature of the battery pack are detected in real time by the second-layer BCU controller. If the temperature of the battery pack exceeds the temperature threshold or the voltage of the battery pack exceeds the voltage threshold range, the battery pack is determined to be in a fault state.

[0008] Preferably, when the first-layer BCU controller completes the charging handshake with the international charging pile and the second-layer BCU controller detects that the battery pack unit is fault-free, the second-layer BCU controller sends the allowable charging parameters of the battery pack assembly to the first-layer BCU controller, and the first-layer BCU controller exchanges information with the international charging pile, and the international charging pile allocates the charging current and charging voltage to the battery pack assembly according to the allowable charging parameters.

[0009] Preferably, a first-layer BCU controller is connected to the vehicle controller; during the charging process, the second-layer BCU controller detects the charging information of the battery pack in real time and sends the charging information to the first-layer BCU controller, and the first-layer BCU controller sends the received charging information to the vehicle controller.

[0010] Preferably, during the charging process, the second-layer BCU controller detects the S0C value of the battery pack in real time. When the S0C value reaches the S0C threshold, the second-layer BCU controller sends a "charging completed" message to the first-layer BCU controller, and the second-layer BCU controller simultaneously controls the second relay to disconnect.

[0011] Preferably, the calculation method of the SOC value of the battery pack is as follows: S1: The second-layer BCU controller obtains the voltage and temperature of the battery pack and determines the reference temperature ; S2: Create OCV-SOC database; S3: Calculate the voltage value of the battery pack after temperature compensation. The calculation method is as follows: ; in, is the voltage value of the battery pack after temperature compensation, The voltage value of the battery pack before temperature compensation, is the current temperature of the battery pack, is the temperature compensation coefficient.

[0012] S4: Find the SOC value corresponding to the voltage value of the battery pack after temperature compensation in the OCV-SOC database.

[0013] Preferably, the communication interaction between the international charging pile and the first-layer BCU controller complies with the GB / T 18487 standard and the GB / T 27930-2015 standard.

[0014] The beneficial effects of the present invention are: the present invention can simultaneously receive battery pack information from multiple second-layer BCU controllers and control the charging status of different battery packs through a first-layer BCU controller, and can realize charging of multiple battery packs at the same time, realizing the purpose of charging multiple parallel battery packs with one international charging pile at the same time, greatly improving the charging speed of the battery power system, shortening the overall charging time, and improving the charging efficiency. In addition, the present invention realizes the information aggregation of multiple battery packs and the information exchange with the charging pile through a single first-layer BCU controller, and controls and manages the simultaneous charging of multiple battery packs, effectively avoiding the complex design architecture that a battery pack needs to be configured with an independent charging seat, making the entire charging system more concise. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a circuit control diagram of the present invention. DETAILED DESCRIPTION

[0016] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0017] Those skilled in the art should understand that, in the disclosure of the present invention, the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0018] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0019] like Figure 1 As shown, a charging control method for a multi-pack parallel battery power system is as follows: The battery power system includes several battery pack assemblies, which include battery packs and a two-layer BCU controller; When charging, the battery pack is connected to the international charging pile through the charging line. The charging line is equipped with an on-off control module, which communicates and interacts with the international charging pile through a layer of BCU controller; After the first-layer BCU controller completes the charging handshake with the international charging pile, the second-layer BCU controller detects the status of the battery pack; when the second-layer BCU controller detects the status of the battery pack as "no fault", the second-layer BCU controller sends the detection result to the first-layer BCU controller, and the first-layer BCU controller sends a "charging allowed" instruction to the battery pack assembly. The second-layer BCU controller controls the on-off control module on the battery pack assembly to close, and the international charging pile charges the battery pack.

[0020] In the present invention, each battery pack corresponds to a second-layer BCU controller, and the second-layer BCU controller is used to detect the status of the battery pack, including voltage detection, current detection, temperature detection, SOC value detection (i.e., detection of the remaining power of the battery pack), fault diagnosis, etc. At the same time, the second-layer BCU controller is also responsible for information exchange with the first-layer BCU controller. The second-layer BCU controller can send battery pack status information to the first-layer BCU controller, and the second-layer BCU controller can also receive command information from the first-layer BCU controller.

[0021] When the battery pack is connected to the charging interface on the international charging pile through the charging line, the connection status of the interface is detected through the first-layer BCU controller. If the charging line is correctly connected to the charging interface on the international charging pile, the first-layer BCU controller detects the connection status of the interface, and the international charging pile and the first-layer BCU controller perform a handshake process of the communication protocol; the first-layer BCU controller can simultaneously receive battery pack information from multiple second-layer BCU controllers and control the charging status of different battery packs, so that multiple battery packs can be charged at the same time, and the purpose of charging multiple parallel battery packs by one international charging pile is achieved, which greatly improves the charging speed of the battery power system, shortens the overall charging time, and improves the charging efficiency. In the present invention, a single first-layer BCU controller is used to realize the information aggregation of multiple battery packs and the information exchange with the charging pile, and control and manage the simultaneous charging of multiple battery packs, which effectively avoids the complex design architecture that a battery pack needs to be configured with an independent charging seat, making the entire charging system more concise.

[0022] The second layer BCU controller is connected to the first layer BCU controller through the signal connector, and the signal transmission between the second layer BCU controller and the first layer BCU controller is realized through the signal connector. In the present invention, the model of the signal connector is HC08B-P16R.

[0023] Among them, the charging circuit includes a first charging cable and a second charging cable, one end of the first charging cable is connected to the positive pole of the battery pack, and the other end of the first charging cable is connected to the positive charging interface on the international charging pile; one end of the second charging cable is connected to the negative pole of the battery pack, and the other end of the second charging cable is connected to the negative charging interface on the international charging pile.

[0024] The on-off control module includes a pre-charging branch arranged on the first charging line, a pre-charging resistor R and a first relay K1 are arranged on the pre-charging branch, and the pre-charging resistor R and the first relay K1 are connected in series; a second relay K2 is arranged on the first charging line, and the pre-charging resistor R and the first relay K1 are connected in parallel with the second relay K2; the on-off of the first relay K1 and the second relay K2 is controlled by the second-layer BCU controller; When the international charging pile charges the battery pack, the second-layer BCU controller first controls the first relay K1 to close and the second relay K2 to disconnect. The charging current of the international charging pile passes through the pre-charging resistor R on the pre-charging branch and pre-charges the battery pack. During the pre-charging process, the second-layer BCU controller detects the status of the battery pack. When the pre-charging time reaches the set time, the second-layer BCU controller controls the second relay K2 to close and the first relay K1 to disconnect. The charging current of the international charging pile charges the battery pack through the first charging line. If during the pre-charging process, the second-layer BCU controller detects that the battery pack is in a faulty state, the second-layer BCU controller controls the second relay to disconnect and sends out an alarm signal.

[0025] When the present invention starts to charge the battery pack, the battery pack is pre-charged first. During pre-charging, the charging current of the international charging pile will flow through the pre-charging resistor, which will play a role in voltage division and current reduction, so that the battery pack is pre-charged with a smaller current at the initial stage of charging, and then switched to the normal charging current. This charging method of first pre-charging with a small current and then increasing the charging current has the following advantages: 1. For batteries that have not been used for a long time or battery packs in a low power state, directly charging with a large current may cause gas to be generated inside the battery or the temperature to rise rapidly, increasing the risk of explosion or fire. Pre-charging with a small current can avoid this situation and improve the safety of charging. 2. Using a smaller initial current can reduce the pressure and heat accumulation inside the battery pack, which helps prevent battery polarization and thus extend the service life of the battery pack. 3. Starting the charging process slowly can reduce the stress between the chemical substances inside the battery and prevent material damage caused by rapid charging. Among them, the pre-charging time can be set in advance according to actual needs. During the charging process, through real-time monitoring of the battery pack status, During the pre-charging process, the voltage and temperature of the battery pack are detected in real time through the second-layer BCU controller. If the temperature of the battery pack exceeds the temperature threshold or the voltage of the battery pack exceeds the voltage threshold range, the battery pack is judged to be in a fault state; otherwise, the battery pack is judged to be in a normal state. The temperature detection of the battery pack is realized by a temperature sensor set on the battery pack. The temperature sensor is connected to the second-layer BCU controller through a temperature sampling line. The temperature information collected by the temperature sensor is transmitted to the second-layer BCU controller through the temperature sampling line. The temperature threshold and voltage threshold range can be set in advance.

[0026] When the first-layer BCU controller completes the charging handshake with the international charging pile and the second-layer BCU controller detects that the battery pack unit is fault-free, the second-layer BCU controller sends the allowable charging parameters of the battery pack assembly to the first-layer BCU controller, and the first-layer BCU controller exchanges information with the international charging pile. The international charging pile allocates the charging current and charging voltage to the battery pack assembly according to the allowable charging parameters. Among them, the allowable charging parameters at least include the allowable charging current value and the allowable charging voltage value. When charging the battery pack, the international charging pile limits the charging current to below the allowable charging current value and the charging voltage to below the allowable charging voltage value, thereby protecting the battery pack and avoiding excessive charging current or charging voltage, which may reduce the service life of the battery pack.

[0027] The first-layer BCU controller is connected to the vehicle controller; during the charging process, the second-layer BCU controller detects the charging information of the battery pack in real time and sends the charging information to the first-layer BCU controller, and the first-layer BCU controller sends the received charging information to the vehicle controller. The charging information is sent to the vehicle controller through the first-layer BCU controller, and the charging information can be displayed on the display interface of the device through the vehicle controller. The charging information may include data such as charging current and battery pack power.

[0028] During the charging process, the second-layer BCU controller detects the SOC value of the battery pack in real time. When the SOC value reaches the SOC threshold, the second-layer BCU controller sends a "charging completed" message to the first-layer BCU controller, and the second-layer BCU controller simultaneously controls the second relay to disconnect to stop the charging process of the battery pack. Among them, the SOC value is the ratio of the remaining battery capacity (Ah) in the battery pack to the battery capacity (Ah) of the battery unit when fully charged, and the ratio is expressed as a percentage.

[0029] Specifically, the calculation method of the SOC value of the battery pack is as follows: S1: The second-layer BCU controller obtains the voltage and temperature of the battery pack and determines the reference temperature ; In the present invention, the reference temperature Determined to be 25°C; S2: Create an OCV-SOC database; the data required for the OCV-SOC database can be provided by the manufacturer of the battery pack, and the OCV-SOC database describes the corresponding relationship between the battery pack at different voltage values ​​and SOC values; S3: Calculate the voltage value of the battery pack after temperature compensation. The calculation method is as follows: ; in, is the voltage value of the battery pack after temperature compensation, The voltage value of the battery pack before temperature compensation, is the current temperature of the battery pack, is the temperature compensation coefficient.

[0030] S4: Find the SOC value corresponding to the voltage value of the battery pack after temperature compensation in the OCV-SOC database.

[0031] The communication interaction between the international charging pile and the first-layer BCU controller complies with the GB / T 18487 standard and the GB / T27930-2015 standard.

[0032] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, all technical solutions that are the same or similar to those of the present application fall within the protection scope of the present invention.

Claims

1. A charging control method for a multi-pack parallel battery power system, characterized in that: Here’s how: The battery power system includes several battery pack assemblies, which include battery packs and a two-layer BCU controller; When charging, the battery pack is connected to the international charging pile through the charging line. The charging line is equipped with an on-off control module, which communicates and interacts with the international charging pile through a layer of BCU controller; After the first-layer BCU controller completes the charging handshake with the international charging pile, the second-layer BCU controller detects the status of the battery pack; when the second-layer BCU controller detects the status of the battery pack as "no fault", the second-layer BCU controller sends the detection result to the first-layer BCU controller, and the first-layer BCU controller sends a "charging allowed" instruction to the battery pack assembly. The second-layer BCU controller controls the on-off control module on the battery pack assembly to close, and the international charging pile charges the battery pack; During the charging process, the second-layer BCU controller detects the SOC value of the battery pack in real time. When the SOC value reaches the SOC threshold, the second-layer BCU controller sends a "charging completed" message to the first-layer BCU controller, and the second-layer BCU controller simultaneously controls the second relay to disconnect; The calculation method of the SOC value of the battery pack is as follows: S1: The second-layer BCU controller obtains the voltage and temperature of the battery pack and determines the reference temperature ; S2: Create OCV-SOC database; S3: Calculate the voltage value of the battery pack after temperature compensation. The calculation method is as follows: ； in, is the voltage value of the battery pack after temperature compensation, The voltage value of the battery pack before temperature compensation, is the current temperature of the battery pack, is the temperature compensation coefficient; S4: Find the SOC value corresponding to the voltage value of the battery pack after temperature compensation in the OCV-SOC database.

2. A charging control method for a multi-pack parallel battery power system according to claim 1, characterized in that: The charging circuit includes a first charging cable and a second charging cable. One end of the first charging cable is connected to the positive pole of the battery pack, and the other end of the first charging cable is connected to the positive charging interface on the international charging pile; one end of the second charging cable is connected to the negative pole of the battery pack, and the other end of the second charging cable is connected to the negative charging interface on the international charging pile.

3. A charging control method for a multi-pack parallel battery power system according to claim 2, characterized in that: The on-off control module includes a pre-charging branch arranged on the first charging line, a pre-charging resistor and a first relay are arranged on the pre-charging branch, and the pre-charging resistor and the first relay are connected in series; a second relay is arranged on the first charging line, and the pre-charging resistor and the first relay are connected in parallel with the second relay; the on-off of the first relay and the second relay is controlled by the second-layer BCU controller; When the international charging pile charges the battery pack, the second-layer BCU controller is used to control the first relay to close and the second relay to disconnect. The charging current of the international charging pile passes through the pre-charging resistor on the pre-charging branch and pre-charges the battery pack. During the pre-charging process, the second-layer BCU controller detects the status of the battery pack. When the pre-charging time reaches the set time, the second-layer BCU controller controls the second relay to close and the first relay to disconnect. The charging current of the international charging pile charges the battery pack through the first charging line. If during the pre-charging process, the second-layer BCU controller detects that the battery pack is in a faulty state, the second-layer BCU controller controls the second relay to disconnect and sends out an alarm signal.

4. A charging control method for a multi-pack parallel battery power system according to claim 3, characterized in that: During the pre-charging process, the voltage and temperature of the battery pack are detected in real time through the second-layer BCU controller. If the temperature of the battery pack exceeds the temperature threshold or the voltage of the battery pack exceeds the voltage threshold range, the battery pack is determined to be in a fault state.

5. A charging control method for a multi-pack parallel battery power system according to claim 1, characterized in that: When the first-layer BCU controller completes the charging handshake with the international charging pile and the second-layer BCU controller detects that the battery pack unit is fault-free, the second-layer BCU controller sends the allowable charging parameters of the battery pack assembly to the first-layer BCU controller, and the first-layer BCU controller exchanges information with the international charging pile. The international charging pile allocates charging current and charging voltage to the battery pack assembly according to the allowable charging parameters.

6. A charging control method for a multi-pack parallel battery power system according to claim 1, characterized in that: The first-layer BCU controller is connected to the vehicle controller; during the charging process, the second-layer BCU controller detects the charging information of the battery pack in real time and sends the charging information to the first-layer BCU controller, and the first-layer BCU controller sends the received charging information to the vehicle controller.

7. A charging control method for a multi-pack parallel battery power system according to claim 1, characterized in that: The communication interaction between the international charging pile and the first-layer BCU controller complies with the GB / T 18487 standard and the GB / T 27930-2015 standard.

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