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CN-116353417-B - Emergency cold start method for 48V battery system

CN116353417BCN 116353417 BCN116353417 BCN 116353417BCN-116353417-B

Abstract

The invention relates to the field of lithium ion batteries and discloses an emergency cold starting method of a 48V battery system, which comprises a 12V battery starting system, a 48V battery system, a DC/DC converter, a VCU/EMS control system and a BSG motor, wherein the low-voltage system comprises a 12V battery, a starter, a display instrument and the like, the 48V battery system comprises a 48V battery, a 48V battery management system and an auxiliary structure, other components are not required to be added in the original battery starting system, and additional design is not required, so that the trouble that a 48V micro-hybrid automobile can provide energy for the 48V battery management system and the DCDC control chip in a state of being incapable of starting the whole automobile is solved.

Inventors

  • YANG NIU
  • LIU CHANGLAI
  • XIA SHIZHONG
  • SUN GUANGZHONG
  • WEI RAN
  • Xie Zhengan

Assignees

  • 骆驼集团新能源电池有限公司

Dates

Publication Date
20260512
Application Date
20221214

Claims (7)

  1. 1. An emergency cold start method for a 48V battery system is characterized by comprising the following steps: in case of a 12V battery deficiency but a 48V battery management system BMS is operable, the following steps are performed: A, starting a key/press key, wherein a VCU/EMS control system receives a starting signal, a 48V battery management system BMS is electrified, and a cold start counting system is started; Judging whether the number of times of emergency cold start of the 48V battery reaches an upper limit m times or not, if so, reminding the emergency cold start of the 48V battery to reach the upper limit m times by the instrument, starting failure, stopping the process, if not, judging the current electric quantity of the 48V battery, if the electric quantity of the 48V battery does not meet the requirement of a preset state of charge value, not starting the process of emergency cold start, reminding the 48V battery of insufficient electric quantity and not starting the process of emergency cold start by the instrument, if the electric quantity of the 48V battery meets the requirement of the preset state of charge value, sending information to the instrument by a BMS (battery management system) of 48V, reminding the 12V battery of electric quantity by the instrument, starting the emergency cold start, controlling the 48V battery relay to be closed by a VCU/EMS (voltage control) system, supplementing the 12V battery by the 48V battery by a DC/DC (voltage/current) converter), wherein the electric supplementing time is T, and after the electric supplementing time is up, sending the information to the instrument by the BMS, reminding the instrument of finishing charging, and starting the vehicle again; c, starting a key/press key, and discharging the 12V battery and the DC/DC converter together to provide cold starting energy for the whole vehicle when the key/press key is started again; D, judging whether the whole vehicle is successfully started, wherein if the whole vehicle is successfully started, an instrument reminds that the emergency cold start is successful, and the count of a cold start counting system is cleared, and if the cold start fails, the count of the cold start counting system is increased by 1; if step B, C, D is repeated for m times continuously, the emergency cold start fails, the number of times of the emergency cold start is reminded to reach the upper limit, the start fails, and the process is stopped.
  2. 2. The method for emergency cold starting of a 48V battery system according to claim 1, wherein m=3.
  3. 3. The method for emergency cold start of a 48V battery system according to claim 1, wherein the instrument in the step B reminds "12V battery is deficient, the start is started by rapid cooling, the time is delayed for 2s, and the instrument reminds" emergency cold start is started ".
  4. 4. An emergency cold start system for a 48V battery system, comprising: The cold start counting system counts the emergency cold start times of the 48V battery; the comparison module is used for judging the current electric quantity of the 48V battery if the counted number of the 48V battery emergency cold starts reaches the upper limit m times of emergency cold starts, executing a suspension flow if the counted number of the 48V battery emergency cold starts reaches the upper limit m times of emergency cold starts, judging the current electric quantity of the 48V battery if the counted number of the 48V battery electric quantity does not meet the requirement of a preset state of charge value, not starting the process of emergency cold starts, sending information to an instrument by a 48V battery management system BMS if the counted number of the 48V battery electric quantity meets the requirement of the preset state of charge value, reminding the instrument of '12V battery shortage, starting emergency cold starts', controlling the 48V battery relay to be closed by a VCU/EMS control system, and supplementing the 12V battery by the 48V battery through a DC/DC converter, wherein the power supplementing time is T; If the cold start fails, the count of the cold start counting system is increased by 1,48V, the number of times that the battery should be quenched and started reaches m times, the emergency cold start fails, the number of times that the battery should be quenched and started reaches an upper limit is reminded, the start fails, and the flow is stopped; and the display module is used for displaying the results of the comparison module and the starting judgment module on the instrument.
  5. 5. A control system for the method for starting the 48V battery system by quenching according to any one of claims 1-3, which is characterized by comprising a 12V battery starting system, a 48V battery system, a DC/DC converter and a VCU/EMS control system, wherein the 12V battery starting system comprises a 12V battery, a starter and an instrument panel; The 48V battery system comprises a 48V battery, a 48V battery management system and a BSG motor; The 12V battery and the 48V battery are grounded at the negative electrode, the positive electrode of the 48V battery is connected with the high-voltage input end of the BSG motor and the DC/DC converter in the 48V battery system, the 48V battery management system is powered by the 12V battery, the 48V battery management system, the BSG motor and the DC/DC converter are communicated with the VCU/EMS control system through the CAN bus, and the 48V battery system is arranged in the VCU/EMS control system by a quenching starting system.
  6. 6. The control system of claim 5, wherein the 12V battery starting system further comprises 12V electric equipment and a low-voltage load, wherein one end of the 12V electric equipment and one end of the low-voltage load are connected with the negative electrode of the 12V battery, and the other end of the 12V electric equipment and the other end of the low-voltage load are connected with the positive electrode of the 12V battery.
  7. 7. The control system of claim 5 wherein the 48V battery system further comprises a 48V high voltage load, one end of the 48V high voltage load being connected to a negative electrode of the power battery and the other end of the 48V high voltage load being connected to a positive electrode of the power battery management system.

Description

Emergency cold start method for 48V battery system Technical Field The invention relates to the field of lithium ion batteries, in particular to an emergency cold start method of a 48V battery system. Background At present, the fuel consumption and emission regulations at home and abroad are increasingly severe, and various large main engine factories begin to develop power systems with ultrahigh fuel economy, and 48V micro-mixing systems are generated. The 48V micro-hybrid system realizes automatic start and stop through a 48V battery system, and the functions of engine stop sliding, sliding and braking energy recovery, acceleration assistance, electric cruising and the like, wherein a 12V battery provides energy for whole vehicle starting, a 12V whole vehicle load and 48V battery management, and the 48V battery provides energy sources for 12V through a DC/DC converter. In certain situations, such as long-term parking, park entertainment, etc., a 12V battery may run out due to a drain on the 12V battery, but the 48V system is not able to power the 12V battery through the DC/DC converter because the 48V battery management system is not operating. The most common practice at present is that the 12V battery is charged by taking electricity or other external charging modes, and when the electric quantity of the 12V battery is enough to meet the starting requirement of the whole vehicle, the whole vehicle power supply system can be normally used, but the mode is time-consuming and labor-consuming, and the driving experience of a customer on the 48V micro-hybrid vehicle is seriously affected. Disclosure of Invention The invention aims to overcome the defects of the technology and provide a strategy capable of normally starting a vehicle under the condition that a 12V battery is insufficient and the whole vehicle cannot be started, but a 48V battery management system and a DC/DC control communication chip can be powered. An emergency cold start method of a 48V battery system, which performs the following steps in the case that 12V batteries are deficient but a 48V battery management system BMS is operable: A, starting a key/press key, wherein a VCU/EMS control system receives a starting signal, a 48V battery management system BMS is electrified, and a cold start counting system is started; Judging whether the number of times of emergency cold start of the 48V battery reaches an upper limit m times or not, if so, reminding the emergency cold start of the 48V battery to reach the upper limit m times by the instrument, starting failure, stopping the process, if not, judging the current electric quantity of the 48V battery, if the electric quantity of the 48V battery does not meet the requirement of a preset state of charge value, not starting the process of emergency cold start, reminding the 48V battery of insufficient electric quantity and not starting the process of emergency cold start by the instrument, if the electric quantity of the 48V battery meets the requirement of the preset state of charge value, sending information to the instrument by a BMS (battery management system) of 48V, reminding the 12V battery of electric quantity by the instrument, starting the emergency cold start, controlling the 48V battery relay to be closed by a VCU/EMS (voltage control) system, supplementing the 12V battery by the 48V battery by a DC/DC (voltage/current) converter), wherein the electric supplementing time is T, and after the electric supplementing time is up, sending the information to the instrument by the BMS, reminding the instrument of finishing charging, and starting the vehicle again; c, starting a key/press key, and discharging the 12V battery and the DC/DC converter together to provide cold starting energy for the whole vehicle when the key/press key is started again; D, judging whether the whole vehicle is successfully started (the whole vehicle starter/engine can normally run and is judged to be successfully started) if the whole vehicle is successfully started, reminding an emergency cold start success by an instrument, and resetting the count of a cold start counting system, if the cold start fails, adding 1 to the count of the cold start counting system; if step B, C, D is repeated for m times continuously, the emergency cold start fails, the number of times of the emergency cold start is reminded to reach the upper limit, the start fails, and the process is stopped. M=3. And B, reminding the 12V battery to be deficient in power by the instrument, starting the battery to be quenched and started, delaying for 2s, and reminding the emergency cold start to be started by the instrument. An emergency cold start system for a 48V battery system, comprising: The cold start counting system counts the emergency cold start times of the 48V battery; the comparison module is used for judging the current electric quantity of the 48V battery if the counted number of the 48V battery emergency cold starts reaches the upper