Electric vehicle multi-battery control method and system

Abstract

The present invention discloses a multi-battery control method and system for electric vehicles. For power supply scenarios with multiple batteries, the optimal discharge strategy is determined by detecting the charger insertion status and battery insertion status. At the same time, not only the battery status and voltage conditions are detected, but also the switch tube temperature is detected, and the collected battery information and temperature information are uploaded to the controller of the vehicle system during the process. The present invention can increase the sales of multi-battery powered vehicles, extend the standby endurance time, extend the battery life time, and provide convenient conditions for the use of multi-battery powered electric vehicles.

Description

Technical Field

[0001] The present invention belongs to the field of electric vehicles, and in particular relates to a multi-battery control method and system for an electric vehicle. Background Art

[0002] Many existing electric vehicles, such as electric cars and electric motorcycles, have multiple batteries. However, if multiple batteries are charged or used without a regular pattern, it will inevitably cause charging waste and inefficient use, and the ultimate impact is likely to be poor endurance, short battery life, frequent charging times, and inability to fully utilize multiple batteries. Therefore, how to control and schedule the charging and operation of multiple batteries so that they can fully exert their discharge capacity, extend endurance, and extend battery life, and how to choose to use different batteries in different environments are technical problems that need to be solved. Summary of the invention

[0003] Purpose of the invention: In order to solve the problem of poor control and scheduling of multiple batteries in electric vehicles in the prior art, the present invention provides a method and system for controlling multiple batteries in electric vehicles.

[0004] Technical solution: A multi-battery control method for an electric vehicle, comprising the following steps:

[0005] Step 1: Check whether the charger is plugged in. If the charger is plugged in, proceed to step 2. If the charger is not plugged in, check whether the control switch is closed. If the control switch is closed, proceed to step 3. If the control switch is disconnected, repeat this step to check whether the charger is plugged in.

[0006] Step 2: Detect whether at least two channels have batteries. If both channels have batteries, determine the SOC of the batteries in the two channels, turn on the switch tube of the channel with the smaller SOC, and discharge the battery with the smaller SOC; if neither channel has batteries, turn on the switch tube of the channel with batteries, and discharge the battery on the channel;

[0007] Step 3: Detect whether at least two channels have batteries. If both channels have batteries, the battery on the first channel is discharged first. If the SOC of the battery in the first channel is less than a preset value, the battery on the second channel is used for discharge, and the battery in the first channel is not used. If neither channel has batteries, the switch tube of the channel with batteries is turned on, and the battery on this channel is discharged.

[0008] Furthermore, the method for detecting whether a charger is inserted in step 1 includes:

[0009] Step a1, defining a charger status flag, wherein the status flag includes an unplug flag, an insert flag, an insert pulse flag, and an unplug pulse flag;

[0010] Step a2, the charger insertion signal is input to the first detection pin of the control unit. If a low level is detected, the charger removal flag is cleared, and the low level delay time is determined. If the low level delay time is a fixed delay time, the insertion pulse flag is set. If the low level delay time is greater than the fixed delay time, the insertion flag is set. If the low level delay time is less than the fixed delay time, step a2 is repeated.

[0011] If a high level is detected, clear the charger insertion flag and determine the high level delay time. If the high level delay time is a fixed delay time, set the pull-out pulse flag position. If the high level delay time is greater than the fixed delay time, set the pull-out flag position. If the high level delay time is less than the fixed delay time, repeat step a2.

[0012] Furthermore, the method of detecting whether there is a battery in the channel in step 2 and step 3 includes:

[0013] Step b1, defining a battery status flag, wherein the status flag includes an unplug flag, an insert flag, and an abnormal flag;

[0014] Step b2, check whether the channel has communication, if yes, clear the battery removal flag, determine whether the communication signal reaches a fixed time, if yes, set the battery insertion flag of the channel, if not, repeat step b2; if no communication, clear the battery insertion flag, determine whether the no communication signal reaches a fixed time, if yes, execute step b3, if not, repeat step b2;

[0015] Step b3, detect whether there is voltage in the channel. If there is voltage, the battery abnormality flag is set, the battery insertion flag of the channel is set, and the battery removal flag of the channel is cleared; if no voltage is detected, the removal flag is set.

[0016] Furthermore, step one also includes whether the control unit outputs a LOCK signal, specifically: when the electric vehicle key switch is closed or the charger is inserted, the LOCK signal is enabled to be output; otherwise, the LOCK signal is not output.

[0017] Furthermore, in step 1, the method for detecting whether the control switch is closed includes:

[0018] Step c1, defining a switch closed state flag, wherein the state flag includes a switch open flag bit and a switch closed flag bit;

[0019] Step c2, detecting whether the circuit where the switch is located is connected. If a connection is detected, clearing the switch disconnection flag, and determining whether the connection holding time reaches a fixed time length. If the fixed time length is reached, setting the switch closing flag position. If the fixed time length is not reached, repeating step c2;

[0020] If no path is detected, clear the switch closed flag and determine whether the circuit breaker holding time reaches a fixed time. If the fixed time is reached, set the switch circuit breaker flag. If the fixed time is not reached, repeat step c2.

[0021] Furthermore, it also includes sending the battery information to a controller of the entire vehicle system.

[0022] Furthermore, during step 2 and step 3, the battery voltage is sampled by the ADC sampling module, and the ADC sampling module also samples the switch tube temperature of each channel. The specific sampling method includes:

[0023] Set the wake-up cycle and timing cycle;

[0024] Detect whether the working state is sleep state or wake-up state. If in sleep state, wait for the wake-up cycle to reach the wake-up state, and then directly start ADC sampling after entering the wake-up state to convert the actual physical value;

[0025] If in the wake-up state, determine whether the timing cycle has been reached. If not, return to the detection working state; if the timing cycle has been reached, determine whether it has just been awakened. If so, it is necessary to wait for all ADCs to be updated once before sampling; if not, perform sampling calculations and convert actual physical values.

[0026] Furthermore, when converting actual physical values, if fast calculation is required, the filtered value is not used to calculate the physical value; if fast calculation is not required, the filtered value is used to calculate the physical value.

[0027] Furthermore, after the battery voltage and the switch tube temperature are sampled, the battery voltage and the switch tube temperature are also sent to the controller of the vehicle system.

[0028] An electric vehicle multi-battery control system used in the above-mentioned electric vehicle multi-battery control method includes a control unit and a charger insertion detection module, a battery insertion detection module, a control switch detection module, an ADC sampling module, a switch tube control module and an information integration communication module connected to the control unit. The information integration communication module is used to integrate the battery information and the temperature information of the switch tube on at least two channels, and then transmit them to the controller or charger of the entire vehicle system through single-line communication.

[0029] The present invention provides a multi-battery control method and system for an electric vehicle, which has the following beneficial effects compared with the prior art:

[0030] According to the situation of charger insertion, battery insertion and control switch, different battery discharges can be switched to make the entire power supply system reach the best working state, thereby extending the battery life, giving full play to the battery discharge capacity, and reducing the number of charging times; the collected battery information and switch tube temperature information are integrated and reported to reflect the working status of multiple batteries in real time, detect abnormalities in time, make timely adjustments, and take timely protection measures for various special abnormal situations. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a flow chart of a multi-battery control method;

[0032] Figure 2 Flowchart for the charger insertion detection part;

[0033] Figure 3 A flowchart for the battery insertion detection part;

[0034] Figure 4 It is the flow chart of switch detection and LOCK signal control part;

[0035] Figure 5 This is the flow chart of the ADC sampling part;

[0036] Figure 6 Flowchart for integrating information for the information integration communication module;

[0037] Figure 7 This is the structural block diagram of the electric vehicle multi-battery control system. DETAILED DESCRIPTION

[0038] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0039] A multi-battery control system for an electric vehicle, such as Figure 7 , including a control unit and a charger insertion detection module, a battery insertion detection module, a control switch detection module, an ADC sampling module, a switch tube control module and an information integration communication module connected to the control unit. The charger insertion detection module is used to detect whether a charger is inserted, the battery insertion detection module is used to detect whether there are batteries online in each channel, the control switch detection module is used to detect whether the key switch of the multi-battery control system is turned on, and the ADC sampling module is used to sample the battery output voltage and MOS tube temperature. Figure 6 As shown, the information integration communication module is used to integrate the battery information and MOS tube temperature information on at least two channels, and then transmit it to the controller or charger of the vehicle system through single-line communication. The control unit adopts Silicon Labs' EFM32HG210F64 series MCU, which is mainly used in the power battery of electric motorcycles.

[0040] The control system is used to select the optimal discharge method according to the charger insertion status and battery insertion status. At the same time, it continuously collects battery voltage and MOS tube temperature information through the ADC sampling module, and integrates the detected battery information and temperature information and sends them to the controller of the vehicle system. The battery information mainly includes battery status, voltage status, etc., so that users can pay attention to the battery status and MOS tube temperature changes at any time.

[0041] On the other hand, the channel battery continuously sends the data it collects to the control unit in a unidirectional manner, does not need to receive polling commands from the main control system, and has complete protection functions (undervoltage protection function, overvoltage protection function, discharge overcurrent protection function, charge overcurrent protection function, overtemperature protection function, low temperature protection function and internal component failure protection function).

[0042] The control unit detects the online battery through voltage and communication, collects the data sent by the module, and after comparison and analysis, controls the corresponding battery to output power or charge.

[0043] The system can be applied to electric vehicles with at least two batteries, or multiple batteries, with the same control concept. In the following, this embodiment takes an electric vehicle with two batteries as an example to reasonably control its batteries.

[0044] A multi-battery control method for an electric vehicle, such as Figure 1 As shown, the following steps are included:

[0045] Step 1: Check whether the charger is plugged in. If the charger is plugged in, proceed to step 2. If the charger is not plugged in, check whether the control switch is closed. If the control switch is closed, proceed to step 3. If the control switch is disconnected, repeat this step to check whether the charger is plugged in.

[0046] Among them, Figure 2 , the method of detecting whether the charger is inserted includes:

[0047] Step a1, defining a charger status flag, wherein the status flag includes an unplug flag, an insert flag, an insert pulse flag, and an unplug pulse flag;

[0048] Step a2, the charger insertion signal is input to the first detection pin of the control unit. If a low level is detected, the charger removal flag is cleared, and the low level delay time is determined. If the low level delay time is a fixed delay time, such as 100ms, the pulse flag is inserted. If the low level delay time is greater than the fixed delay time, the insertion flag is set. If the low level delay time is less than the fixed delay time, step a2 is repeated.

[0049] If a high level is detected, clear the charger insertion flag and determine the high level delay time. If the high level delay time is a fixed delay time, set the pull-out pulse flag position. If the high level delay time is greater than the fixed delay time, set the pull-out flag position. If the high level delay time is less than the fixed delay time, repeat step a2.

[0050] Among them, Figure 4 , the method for detecting whether the control switch is closed includes:

[0051] Step c1, defining a switch closing state flag, wherein the state flag includes a switch disconnection flag and a switch closing flag;

[0052] Step c2, detect whether the circuit where the switch is located is connected. If a connection is detected, clear the switch disconnection flag, and determine whether the connection holding time reaches a fixed time of 100ms. If the fixed time is reached, the switch closing flag is set. If the fixed time is not reached, repeat step c2;

[0053] If no path is detected, clear the switch closed flag and determine whether the circuit breaker holding time reaches a fixed time. If the fixed time is reached, set the switch circuit breaker flag. If the fixed time is not reached, repeat step c2.

[0054] This step also includes whether the control unit outputs a LOCK signal, and the LOCK signal is output to the battery to activate the battery. Specifically, when the electric vehicle key switch is closed or the charger is inserted, the LOCK signal is enabled to be output; otherwise, the LOCK signal is not output.

[0055] Step 2: Check whether both channels have batteries. If both channels have batteries, determine the SOC of the batteries in the two channels, turn on the switch tube of the channel with the smaller SOC, and discharge the battery with the smaller SOC. If neither channel has batteries, turn on the switch tube of the channel with batteries, and discharge the battery on this channel.

[0056] Step 3: Check whether both channels have batteries. If both channels have batteries, the battery on the first channel is discharged first. If the SOC of the battery on the first channel is less than the preset value, such as 20%, the battery on the second channel is used for discharge, and the battery on the first channel is not used. If neither channel has batteries, the switch tube of the channel with batteries is turned on to discharge the battery on the channel. Only one channel is turned on at a time, and two channels cannot be turned on at the same time, that is, only one battery is discharged at a time.

[0057] The switch tube refers to a MOS tube. Whether the battery discharges or not is controlled by controlling the MOS tube switch. If a battery needs to be discharged, the MOS tube driving the battery is turned on accordingly.

[0058] Among them, Figure 3 The method for detecting whether a channel has a battery online in step 2 and step 3 includes:

[0059] Step b1, defining a battery status flag, wherein the status flag includes an unplug flag, an insert flag, and an abnormal flag;

[0060] Step b2, check whether the channel has communication, if yes, clear the battery removal flag, determine whether the communication signal reaches a fixed time, such as 10ms, if it reaches the battery insertion flag of the channel, if not, repeat step b2; if there is no communication, clear the battery insertion flag, determine whether the no communication signal reaches a fixed time, if it reaches, execute step b3, if not, repeat step b2;

[0061] Step b3, detect whether there is voltage in the channel. If there is voltage, the battery abnormality flag is set, the battery insertion flag of the channel is set, and the battery removal flag of the channel is cleared; if no voltage is detected, the removal flag is set.

[0062] During step 2 and step 3, the battery output voltage is sampled by the ADC sampling module, and the temperature of the MOS tube is also detected at the same time. The temperature sampling is also controlled by the ADC sampling module. Figure 5 Specific sampling methods include:

[0063] Set the wake-up period and timing period. For example, in this embodiment, the wake-up period is 1s and the timing period is 10ms.

[0064] Detect whether the working state is sleep state or wake-up state. If in sleep state, wait for the wake-up cycle to reach the wake-up state. After entering the wake-up state, directly start ADC sampling and convert the actual physical value, which includes the battery output voltage and MOS tube temperature;

[0065] If in the awake state, determine whether the timing cycle is reached. If not, return to the detection working state; if the timing cycle is reached, determine whether it has just been awakened. If so, it is necessary to wait for all ADCs to be updated once before sampling; if not, perform sampling calculations and convert actual physical values. If fast calculations are required, do not use filtered values ​​to calculate physical values; if fast calculations are not required, use filtered values ​​to calculate physical values.

[0066] The batteries of the two channels communicate with the control unit of the multi-battery control system through a single line. After sampling the battery voltage and temperature information, the control unit integrates the battery information and temperature information of the two channels and sends it to the controller or charger of the vehicle system through a single line communication. Secondly, the single line for communication with the charger or controller can also be configured as a serial port communication for the program upgrade and configuration of the control unit of the multi-battery control system.

Claims

1. A multi-battery control method for an electric vehicle, characterized in that: The following steps are involved: Step 1: Check whether the charger is plugged in. If the charger is plugged in, proceed to step 2. If the charger is not plugged in, check whether the control switch is closed. If the control switch is closed, proceed to step 3. If the control switch is disconnected, repeat this step to check whether the charger is plugged in. Among them, the method for detecting whether the charger is inserted includes: Step a1, defining a charger status flag, wherein the status flag includes an unplug flag, an insert flag, an insert pulse flag, and an unplug pulse flag; Step a2, the charger insertion signal is input to the first detection pin of the control unit. If a low level is detected, the charger removal flag is cleared, and the low level delay time is determined. If the low level delay time is a fixed delay time, the insertion pulse flag is set. If the low level delay time is greater than the fixed delay time, the insertion flag is set. If the low level delay time is less than the fixed delay time, step a2 is repeated. If a high level is detected, the charger insertion flag is cleared, and the high level delay time is determined. If the high level delay time is a fixed delay time, the pull-out pulse flag is set. If the high level delay time is greater than the fixed delay time, the pull-out flag is set. If the high level delay time is less than the fixed delay time, step a2 is repeated. Step 2: Detect whether at least two channels have batteries. If both channels have batteries, determine the SOC of the batteries in the two channels, turn on the switch tube of the channel with the smaller SOC, and discharge the battery with the smaller SOC; if neither channel has batteries, turn on the switch tube of the channel with batteries, and discharge the battery on the channel; Step 3: Detect whether at least two channels have batteries. If both channels have batteries, the battery on the first channel is discharged first. If the SOC of the battery on the first channel is less than a preset value, the battery on the second channel is used for discharge, and the battery on the first channel is not used. If neither channel has batteries, the switch tube of the channel with batteries is turned on, and the battery on the channel is discharged. The method for detecting whether there is a battery in the channel in step 2 and step 3 includes: Step b1, defining a battery status flag, wherein the status flag includes an unplug flag, an insert flag, and an abnormal flag; Step b2, check whether the channel has communication, if yes, clear the battery removal flag, determine whether the communication signal reaches a fixed time, if yes, set the battery insertion flag of the channel, if not, repeat step b2; if no communication, clear the battery insertion flag, determine whether the no communication signal reaches a fixed time, if yes, execute step b3, if not, repeat step b2; Step b3, detect whether there is voltage in the channel. If there is voltage, the battery abnormality flag is set, the battery insertion flag of the channel is set, and the battery removal flag of the channel is cleared; if no voltage is detected, the removal flag is set.

2. The electric vehicle multi-battery control method according to claim 1, characterized in that: Step 1 also includes whether the control unit outputs a LOCK signal, and the LOCK signal is used to activate the battery. Specifically, when the electric vehicle key switch is closed or the charger is inserted, the LOCK signal is enabled to be output; otherwise, the LOCK signal is not output.

3. The electric vehicle multi-battery control method according to claim 2, characterized in that: In step 1, the method for detecting whether the control switch is closed includes: Step c1, defining a switch closing state flag, wherein the state flag includes a switch disconnection flag and a switch closing flag; Step c2, detecting whether the circuit where the switch is located is connected. If a connection is detected, clearing the switch disconnection flag, and determining whether the connection holding time reaches a fixed time length. If the fixed time length is reached, setting the switch closing flag position. If the fixed time length is not reached, repeating step c2; If no path is detected, clear the switch closed flag and determine whether the circuit breaker holding time reaches a fixed time. If the fixed time is reached, set the switch circuit breaker flag. If the fixed time is not reached, repeat step c2.

4. The electric vehicle multi-battery control method according to claim 1, characterized in that: It also includes a controller that sends battery information to the entire vehicle system.

5. The electric vehicle multi-battery control method according to claim 1 or 2, characterized in that: During step 2 and step 3, the battery voltage is sampled by the ADC sampling module. The ADC sampling module also samples the switch tube temperature of each channel. The specific sampling method includes: Set the wake-up cycle and timing cycle; Detect whether the working state is sleep state or wake-up state. If in sleep state, wait for the wake-up cycle to reach the wake-up state, and then directly start ADC sampling after entering the wake-up state to convert the actual physical value; If in the wake-up state, determine whether the timing cycle has been reached. If not, return to the detection working state; if the timing cycle has been reached, determine whether it has just been awakened. If so, it is necessary to wait for all ADCs to be updated once before sampling; if not, perform sampling calculations and convert actual physical values.

6. The electric vehicle multi-battery control method according to claim 5, characterized in that: When converting actual physical values, if fast calculation is required, the filtered value is not used to calculate the physical value; if fast calculation is not required, the filtered value is used to calculate the physical value.

7. The electric vehicle multi-battery control method according to claim 6, characterized in that: After sampling the battery voltage and the switch tube temperature, the battery voltage and the switch tube temperature are also sent to the controller of the vehicle system.

8. An electric vehicle multi-battery control system used in the electric vehicle multi-battery control method according to any one of claims 1 to 7, characterized in that: It includes a control unit and a charger insertion detection module, a battery insertion detection module, a control switch detection module, an ADC sampling module, a switch tube control module and an information integration communication module connected to the control unit. The information integration communication module is used to integrate the battery information and the temperature information of the switch tube on at least two channels, and then transmit them to the controller or charger of the whole vehicle system through single-line communication.

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