DCDC control method based on battery management system

Abstract

The invention discloses a DCDC control method based on a battery management system. The method comprises the following steps: dividing power utilization conditions into 110V auxiliary load power supply and 500V high-voltage traction power supply; when the 110V auxiliary load supplies power, the DCDC converter is forbidden, and the storage battery directly supplies power; during 500V high-voltage traction power supply, starting and stopping of the DCDC are automatically controlled in combination with a control instruction of a vehicle network system, BMS real-time data and an internal strategy. The DCDC control method based on the battery management system is high in efficiency, stable, low in interference and good in compatibility, and the overall performance and reliability of the lithium battery system are improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of lithium batteries, and specifically relates to a DCDC control method based on a battery management system. BACKGROUND

[0002] In modern lithium battery applications, the importance of the battery management system (BMS) is increasingly prominent. BMS is not only a tool for monitoring and protecting batteries, but also a key technology for optimizing battery performance, improving energy utilization, and prolonging battery life. As a core component in BMS, the control method of the direct current-direct current (DCDC) converter directly affects the overall performance of the battery system. Traditional DCDC control methods face problems such as energy waste, slow dynamic response, and large electromagnetic interference, especially when the battery load changes significantly or the environmental temperature changes dramatically.

[0003] Therefore, in order to overcome the limitations in the prior art, it is particularly urgent and necessary to develop a more advanced DCDC control method based on BMS. However, this method should not only have high-efficiency, high-precision battery voltage regulation capability, but also consider stability and reliability under various working conditions. At the same time, this technology also needs to be compatible with existing battery management systems and control strategies in order to facilitate rapid application and promotion. SUMMARY

[0004] In view of the deficiencies in the prior art, the present application provides a DCDC control method based on a battery management system, which comprises: Divide the power consumption conditions into 110V auxiliary load power supply and 500V high-voltage traction power supply; When the 110V auxiliary load power supply is used, disable the DCDC converter and directly power the battery; When the 500V high-voltage traction power supply is used, combine the control instructions of the vehicle network system, the real-time data of the BMS, and the internal strategy to automatically control the start and stop of the DCDC.

[0005] Further, the combination of the control instructions of the vehicle network system, the real-time data of the BMS, and the internal strategy to automatically control the start and stop of the DCDC specifically includes: The BMS communicates with the vehicle control system through the TRDP protocol, and uploads the battery state, fault and detection data in real time; The vehicle control system sends a battery traction preparation signal and a traction start signal; The BMS judges the battery traction conditions according to the preparation signal and controls the start and stop of the DCDC according to the start signal.

[0006] Further, the BMS judges the battery traction conditions according to the preparation signal, specifically including: The ratio of the maximum energy consumption during traction to the total power configured for the whole vehicle is calculated to determine the minimum traction SOC and the corresponding open-circuit total voltage; When the battery SOC is not less than the minimum traction SOC, the voltage is not less than the corresponding open-circuit total voltage, and there is no fault, the battery OK signal is output.

[0007] Further, after receiving the traction start signal, the BMS no longer judges the voltage, continuously outputs the battery OK signal, and sends a start signal to the DCDC after self-checking is successful.

[0008] Further, the battery traction preparation signal, the battery OK signal, and the battery start signal are designed with network and hard-wire dual redundancy, and any one signal is effective.

[0009] Further, the method further comprises data acquisition and processing, specifically comprising: Confirming that each acquisition sensor is working normally; Pretreating the acquired battery state data and DCDC working state data, Excluding abnormal values and noise interference.

[0010] Further, the method further comprises DCDC fault detection, specifically comprising: Overvoltage, overcurrent, overtemperature, and undervoltage protection detection are performed on the DCDC components; When overvoltage, overcurrent, overtemperature, or undervoltage is detected, DCDC shutdown protection is triggered.

[0011] Further, the method further comprises BMS fault detection, specifically comprising: The BMS classifies the detected battery overvoltage, overcurrent, overtemperature, and undervoltage faults; According to the fault level, it is determined whether to start the DCDC to respond to the vehicle traction demand.

[0012] Further, the BMS and the DCDC are directly connected through a shielded wire harness for anti-interference signal transmission.

[0013] Further, the minimum traction SOC = (maximum traction energy consumption + auxiliary load energy consumption) / total power configured for the whole vehicle * 100%.

[0014] The present application has the following technical effects: 1. High efficiency and energy saving: By working condition control, the DCDC is avoided from starting when the 110V auxiliary load is powered, the energy conversion loss is reduced, and the system energy utilization rate is improved by more than 30%; 2. Dynamic response optimization: Based on the coordinated control of real-time BMS data and vehicle commands, the dynamic response time of DC-DC is shortened to less than 50ms, ensuring stable output under complex operating conditions; 3. Improved Electromagnetic Compatibility: Through high and low voltage isolation design, direct connection of shielded wiring harnesses, and anti-interference protocol constraints, the electromagnetic interference intensity is reduced by 40%, meeting EMC standard requirements; 4. Enhanced compatibility: Adopting a modular design, it unifies the DC-DC input terminal, communication interface and control commands, and can be seamlessly integrated into different BMS systems to adapt to various project requirements.

[0015] This invention provides a high-efficiency, stable, low-interference, and highly compatible DC-DC control method based on a battery management system (BMS), which improves the overall performance and reliability of lithium battery systems. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the control method of the present invention; Figure 2 This is a schematic diagram of the design principle of the present invention; Figure 3 This is a flowchart of the BMS strategy of the present invention. Detailed Implementation

[0017] The present invention will now be described in detail with reference to the accompanying drawings.

[0018] The objective of this invention is to provide a high-efficiency, stable, low-interference, and highly compatible DC-DC control method based on a battery management system (BMS) to improve the overall performance and reliability of lithium battery systems.

[0019] From a design perspective, considering energy conservation, safety, and practicality, such as Figure 1 flow chart, Figure 2 As shown in the design schematic, the method of this invention divides the actual power consumption conditions into 110V auxiliary load power supply and 500V high-voltage traction power supply. The battery itself can meet the 110V auxiliary load power supply voltage requirements, and there is no need to start the DC-DC converter to avoid energy waste. When the 500V high-voltage traction is used, the DC-DC converter is automatically controlled to turn on and off after receiving control commands from the vehicle network system, real-time effective data from the BMS, and internal strategies.

[0020] Data acquisition and processing: Confirm that all acquisition sensors are working properly, preprocess and filter the acquired data to eliminate outliers and noise interference; BMS control strategy: such as Figure 3BMS strategy flow chart shown, received whole vehicle to give "battery traction preparation" signal, first calculate the maximum energy consumption (including auxiliary) and the whole vehicle configuration power ratio for the minimum traction SOC, and the corresponding open circuit total voltage at this time, that is considered to meet no less than this SOC and the corresponding open circuit total voltage has battery traction ability, after the merger battery has no other faults, BMS output "battery OK signal", for the whole vehicle to determine whether the battery has traction ability. Then receive "battery traction start" signal no longer judge voltage, and always high level output "battery ok" signal. As long as the battery has no any serious fault, "battery ok" signal remains, until "battery traction start" signal or "battery traction preparation" signal disappears. BMS receives "battery traction start" signal, self-test success after sending start signal to DCDC. "Battery traction preparation", "battery ok" and "battery start signal" are network and hard line double redundancy, any one exists, it is considered that the signal is effective.

[0021] DCDC fault strategy: make technical requirements for DCDC, including but not limited to overvoltage, overcurrent, overtemperature and undervoltage protection detected by DCDC components themselves; BMS fault strategy: BMS classifies the detected faults to determine whether to start DCDC to respond to the traction demand of the vehicle, including but not limited to overvoltage, overcurrent, overtemperature and undervoltage protection; In view of the defects in the prior art, the present application aims to solve 1. Energy waste: the existing DCDC control method will start DCDC as long as there is load power consumption due to the hardware reasons such as battery configuration, resulting in certain energy loss. The present application avoids the energy consumption of starting and stopping DCDC when the 110V auxiliary load is powered on by optimizing the control strategy and circuit design, thereby improving the energy utilization rate of the whole lithium battery system.

[0022] 2. Unstable dynamic response: the traditional DCDC control method cannot respond in time when facing various complex working conditions, resulting in unstable system. The present application uses more advanced control strategy and more stable communication mode to improve the dynamic response speed of DCDC converter, ensuring stable output in various working conditions.

[0023] 3. Electromagnetic interference problem: electromagnetic interference (EMI) is a common problem of DCDC converter, which can seriously affect the normal work of other electronic equipment. The present application reduces electromagnetic interference and improves the electromagnetic compatibility of the system by improving the circuit design and using more effective shielding measures.

[0024] 4. Poor compatibility: Some existing DCDC control methods have poor compatibility with existing battery management systems (BMS), increasing the complexity and cost of implementation. The present application designs a more compatible DCDC control method that can seamlessly integrate with existing BMS, simplifying the design and implementation process of the system.

[0025] The above description is merely preferred embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims. The information disclosed in the background section of the present application is merely intended to deepen the understanding of the overall background of the present application, and should not be regarded as acknowledging or implying in any form that the information constitutes prior art known to those skilled in the art.

Claims

1. A DC-DC control method based on a battery management system, characterized in that, The method includes: The power supply conditions are divided into 110V auxiliary load power supply and 500V high-voltage traction power supply; When the auxiliary load is powered by 110V, the DC-DC converter is disabled and the battery supplies power directly. When using 500V high-voltage traction power supply, the start and stop of the DC-DC converter are automatically controlled by combining the control commands of the vehicle network system, real-time data of the BMS, and internal strategies.

2. The control method as described in claim 1, characterized in that, The automatic control of the start and stop of the DC-DC converter, which combines control commands from the vehicle network system, real-time data from the BMS, and internal policies, specifically includes: The BMS communicates with the vehicle control system via the TRDP protocol, uploading battery status, fault and detection data in real time. The vehicle control system sends out a battery traction preparation signal and a traction start signal; The BMS determines the battery traction conditions based on the preparatory signal and controls the start and stop of the DC-DC converter based on the start signal.

3. The control method as described in claim 2, characterized in that, The BMS determines the battery traction conditions based on the preparatory signal, specifically including: Calculate the ratio of maximum energy consumption during traction to the total vehicle power capacity to determine the minimum towing SOC and the corresponding total open-circuit voltage; When the battery SOC is not less than the minimum traction SOC, the voltage is not less than the corresponding open-circuit total voltage, and there is no fault, the battery OK signal is output.

4. The control method as described in claim 3, characterized in that, After receiving the traction start signal, the BMS no longer checks the voltage, continuously outputs the battery OK signal, and sends a start signal to the DC-DC converter after a successful self-test.

5. The control method according to any one of claims 2-4, characterized in that, The battery traction preparation signal, battery OK signal, and battery start signal adopt a dual redundancy design of network and hard wiring, and any valid signal is considered valid.

6. The control method as described in claim 1, characterized in that, The method also includes data acquisition and processing, specifically including: Confirm that all data acquisition sensors are functioning properly; The collected battery status data and DC-DC operating status data are preprocessed to remove outliers and noise interference.

7. The control method as described in claim 1, characterized in that, The method also includes DCDC fault detection, specifically including: Perform overvoltage, overcurrent, overtemperature, and undervoltage protection tests on DC-DC components; When overvoltage, overcurrent, overtemperature, or undervoltage is detected, the DC-DC shutdown protection is triggered.

8. The control method as described in claim 1, characterized in that, The method also includes BMS fault detection, specifically including: The BMS classifies detected battery overvoltage, overcurrent, overtemperature, and undervoltage faults. Whether to activate DC-DC to respond to vehicle towing needs is determined based on the fault level.

9. The control method as described in claim 1, characterized in that, The BMS and DCDC are directly connected via shielded cable harnesses to achieve interference immunity in signal transmission.

10. The control method as described in claim 3, characterized in that, The minimum towing SOC is calculated as follows: (maximum traction energy consumption + auxiliary load energy consumption) / total vehicle power consumption × 100%.

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