Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a power battery self-starting control system and a power battery self-starting control method, so that a temperature control device of a battery can be started when a vehicle is in a parking state, and the starting time of heating and cooling the battery of an electric vehicle is avoided.
In order to achieve the purpose, the invention adopts the technical scheme that: a power battery self-starting control system comprises a battery control unit BCU, a battery management unit BMU and an ambient temperature sensor, wherein the battery control unit BCU is respectively connected with the ambient temperature sensor and the battery management unit BMU, and the output end of the battery control unit BCU is connected with a battery temperature control module; the power supply input end of the battery control unit BCU is connected with the vehicle-mounted low-voltage storage battery through a switch; the control system further comprises a power battery conversion power supply loop, one end of the power battery conversion power supply loop is connected with the power battery, and the other end of the power battery conversion power supply loop is connected to the battery control unit BCU.
The power battery conversion power supply loop comprises a DCDC converter, a fuse F1 and a diode D1, wherein the power input end of the DCDC converter is connected with the power output end of the power battery through the fuse F1, the power output end of the DCDC converter is connected with a Battery Control Unit (BCU) through the diode D1, and the power output end of the DCDC converter is connected with the enabling awakening input end of the Battery Control Unit (BCU).
The drive control input end of the DCDC converter is connected with the high-level drive output end of the battery control unit, and the CAN communication interface of the DCDC converter is connected with the CAN interface of the battery control unit.
The battery temperature control module comprises a control relay and a temperature control device, the output end of the battery control unit BCU is connected with the control relay, one end of a main contact of the control relay is connected with the anode of the temperature control device, the other end of the main contact of the control relay is connected with the anode of the power battery through a fuse F2, and the cathode of the power battery is connected with the cathode of the temperature control device.
The temperature control device comprises a heating device and a cooling device, the heating device is used for heating and controlling the battery pack, and the cooling device is used for cooling and controlling the battery pack.
And an anti-reverse diode D2 is connected in series between the vehicle-mounted low-voltage storage battery and the battery control unit BCU.
And the driving input end of the DCDC converter is respectively connected to a charging pile A + signal line and a key gear KEYON signal line.
The output end of the battery control unit BCU is connected with a battery balancing device, and the battery balancing device is used for carrying out balancing control on the battery.
A control method of a power battery self-starting control system comprises the following steps:
when the vehicle is in a driving state: at the moment, a switch in a power supply loop of the vehicle-mounted low-voltage storage battery for the battery control unit is closed, the vehicle-mounted low-voltage storage battery supplies power for a BCU (battery control unit), and meanwhile, a KEYON signal is activated, so that the BCU of the battery management system is activated to work; the KEYON signal received by the DCDC converter is effective, and the DCDC does not output low voltage; the BMS sets DCDC self-starting time to the DCDC through the CAN message;
when the vehicle is in a charging state, the switch in the power supply loop of the vehicle-mounted low-voltage storage battery for the battery control unit is closed at the moment, the charging pile A + wakes up the DCDC converter, the DCDC converter starts to work and then converts the output high voltage of the power battery into a low-voltage power supply for supplying power to the BMS, meanwhile, the A + signal of the charging pile wakes up the BMS, the working state of the DCDC converter is output to the BMS through a CAN message after the DCDC converter works, and at the moment, the working state of the DCDC converter is controlled by the CAN message, the high-level drive signal;
when a vehicle is in a parking state, a switch in a power supply loop of a battery control unit is closed by a vehicle-mounted low-voltage storage battery, a BCU is in a power-off or dormant state, a BMU is in a power-off or dormant state, a DCDC converter is in a dormant state, when DCDC reaches self-awakening time, the DCDC is started and outputs a low-voltage power supply, the BCU normally works after obtaining a power supply and an awakening signal supplied by the DCDC, meanwhile, the BCU supplies power to the BMU to enable the BMU to normally work, and at the moment, the DCDC, the BCU and the BMU interact through CAN communication information; and the BCU controls whether the temperature control module works or not according to the detected temperature signal.
When the BCU, the BMU and the DCDC stably work, the BCU detects the ambient temperature and the BMU detects the temperature of the power battery, and when the difference value between the temperature of the power battery and the ambient temperature is lower than a software set threshold and the temperature of the power battery is lower than a software set value, the BCU enters a heating process according to the software setting to preheat the power battery pack; when the difference value between the temperature of the power battery and the ambient temperature is higher than the software set threshold value and the temperature of the power battery is higher than the software set value, the BCU controls the heating to stop; and setting a next self-awakening period for the DCDC, disconnecting the control for awakening the DCDC and keeping the normal output of the DCDC, stopping the output of the DCDC after the DCDC does not have the control, and enabling the whole system to enter a power-off or sleep state to wait for the next start.
The BMS CAN set DCDC self-starting time to the DCDC through the CAN message; BCU is set in a driving or charging state or the set self-starting time is sent through a remote terminal, so that starting can be carried out according to the set time.
The invention has the advantages that: can supply power for BCU after the DCDC conversion through power battery under the condition of vehicle parking to accomplish preheating or cooling for power battery under the condition of parking, thereby can realize preheating fast and starting or cooling start-up of vehicle, reduce the influence that battery temperature waited for the start-up time, improve the comfort level and the user experience of vehicle.
Detailed Description
The following description of preferred embodiments of the invention will be made in further detail with reference to the accompanying drawings.
The main purpose of this application is to solve prior art, after the vehicle parks and puts out fire, behind battery management system's the BCU outage, heating device or the water cooling system work of uncontrollable power battery for the vehicle is in low temperature or high temperature state always, and when the user need start the vehicle, need carry out temperature control under low temperature, the high temperature and reach power battery's operating temperature, makes the start-up time extension, influences user experience. This application includes that heating device, water cooling plant all set up and are used for realizing the function that corresponds in the power battery. The following description will be made by taking a heating apparatus as an example.
As shown in fig. 1, which is a schematic diagram of start-up control of a heating device in the prior art, since power performance of a power lithium battery is different at different environmental temperatures, in order to overcome the influence of low temperature on the performance of the power lithium battery, a heating device must be used to heat the power lithium battery. In fig. 1, the entire frame thereof comprises: a power lithium battery pack (including a bmu (battery management unit) and a heating device for heating the battery), a bcu (battery control unit), a switch, a relay, a fuse and the like, as shown in fig. 1.
Power supply aspect in fig. 1: the BCU is supplied with power by a lead-acid storage battery of the whole vehicle. The BMU in the power lithium battery pack is powered by the BCU. The heating device is powered by the power battery, and the power requirement of the heating device can be met by the low-rate discharge of the power lithium battery at low temperature due to the low power of the heating device. And the BCU is used for attracting or disconnecting the heating relay according to the set conditions of the software. In the aspect of communication: and the BCU and the BMU carry out information interaction through the inner CAN.
In the existing application scheme, the power consumption problem under the condition that the whole vehicle is not loaded is considered, the power shortage of the lead-acid storage battery is prevented, and in the power-off parking state of the vehicle, a switch between the lead-acid storage battery and a BCU is in a disconnected state. The whole battery system is free of low-voltage power supply, and the system is in a non-operating state. However, when the whole vehicle passes through the low temperature in the north at night, the temperature of the power lithium battery becomes very low, and the discharge power is not enough to support the high power required by the motor during driving in the morning. At the moment, the heating relay is started again to heat the power battery, so that the hot vehicle time is prolonged, and poor vehicle using experience is caused.
As shown in fig. 2, a power battery self-starting control system includes a battery control unit BCU, a battery management unit BMU, and an ambient temperature sensor, where the battery control unit BCU is connected to the ambient temperature sensor and the battery management unit BMU, respectively, and a control output end of the battery control unit BCU is connected to a battery temperature control module; the power supply input end of the battery control unit BCU is connected with the vehicle-mounted low-voltage storage battery through a switch; the control system further comprises a power battery conversion power supply loop, one end of the power battery conversion power supply loop is connected with the power battery, and the other end of the power battery conversion power supply loop is connected to the battery control unit BCU. The battery temperature control module includes heating module and water-cooling module, and the heating module includes relay and the heating device who corresponds for heating control, and the water-cooling module includes relay and the water cooling system who corresponds for water-cooling, and this application describes with heating device, and water cooling system and heating device are the same to be set up.
The vehicle-mounted low-voltage storage battery is connected with the anode of a diode D3 through a manual switch K, the cathode of D2 is connected with the power supply input anode of the BCU, the cathode of the vehicle-mounted low-voltage storage battery is connected with the power supply input cathode of the BCU, and the vehicle-mounted low-voltage storage battery is a lead storage battery.
The power battery conversion power supply loop comprises a DCDC converter, a fuse F1 and a diode D1, wherein the power input anode of the DCDC converter is connected with the power output anode of the power battery through a fuse F1, and the power input cathode of the DCDC converter is connected with the cathode of the power battery. The positive pole of the power supply output of the DCDC converter is connected with the positive pole of the diode D1, the negative pole of the diode D1 is connected with the positive pole of the power supply input of the BCU, the negative pole of the DCDC converter is connected with the negative pole of the power supply input of the battery control unit BCU, and meanwhile, the positive pole of the power supply output of the DCDC converter is connected with the enabling awakening input end of the battery control unit BCU.
The drive control input end of the DCDC converter is connected with the high-level drive output end of the battery control unit BCU and used for receiving a drive control signal of the BCU; the CAN communication interface of the DCDC converter is connected with the CAN interface of the battery control unit and used for realizing the sending and receiving of CAN data between the DCDC converter and the BCU and sending the setting parameters for the subsequent DCDC self-starting to the DCDC converter.
The heating control signal output end of the battery control unit BCU is connected with the heating relay and used for driving the heating relay to be switched on and switched off, one end of a main contact of the control relay is connected with the anode of the heating device, the other end of the main contact of the control relay is connected with the anode of the power battery through the fuse F2, and the cathode of the heating device is connected with the cathode of the power battery. The control mode of the water cooling device is consistent with that of the heating device, the output end of a water cooling control signal of the BCU is connected with a water cooling relay, one end of the water cooling relay is connected with the anode of the water cooling device, the other end of the water cooling relay is connected with the anode of a power battery through a fuse, the cathode of the power battery is connected with the cathode of the cooling device, and the connection of the cathode and the cathode takes whether the power supply of an electric appliance in the cooling device is.
The driving input end of the DCDC converter is respectively connected to a charging pile A + signal line and a key gear KEYON signal line and is used for receiving an A + signal and a key gear KEYON signal. For drive control DCDC according to the signal.
This application not only can be under the vehicle behind the electricity heating control, can also carry out battery equalizing control, and battery balancing unit is connected to battery control unit BCU's output, battery equalizing unit is used for carrying out equalizing control to the battery. Equalization starting conditions can be preset in the BCU according to needs, and therefore equalization is completed.
The BCU is mainly used for controlling control during power-off parking and self-starting time control of the DCDC, and sends self-starting time and parameters to the DCDC converter through the CAN bus. BCU and TBOX pass through CAN network connection, integrate 2G communication module in the TBOX, through operation terminals such as TBOX's 2G communication connection cell-phone, intelligent key, CAN set up DCDC dormancy after the start-up time or cycle start frequency time etc..
A control method of a power battery self-starting control system comprises the following steps:
when the vehicle is in a driving state: at the moment, a switch in a power supply loop of the vehicle-mounted low-voltage storage battery for the battery control unit is closed, the vehicle-mounted low-voltage storage battery supplies power for a BCU (battery control unit), and meanwhile, a KEYON signal is activated, so that the BCU of the battery management system is activated to work; the KEYON signal received by the DCDC converter is effective, and the DCDC does not output low voltage; the BMS sets DCDC self-starting time to the DCDC through the CAN message;
when the vehicle is in a charging state, the switch in the power supply loop of the vehicle-mounted low-voltage storage battery for the battery control unit is closed at the moment, the charging pile A + wakes up the DCDC converter, the DCDC converter starts to work and then converts the output high voltage of the power battery into a low-voltage power supply for supplying power to the BMS, meanwhile, the A + signal of the charging pile wakes up the BMS, the working state of the DCDC converter is output to the BMS through a CAN message after the DCDC converter works, and at the moment, the working state of the DCDC converter is controlled by the CAN message, the high-level drive signal;
when a vehicle is in a parking state, a switch in a power supply loop of a battery control unit is closed by a vehicle-mounted low-voltage storage battery, a BCU is in a power-off or dormant state, a BMU is in a power-off or dormant state, a DCDC converter is in a dormant state, when DCDC reaches self-awakening time, the DCDC is started and outputs a low-voltage power supply, the BCU normally works after obtaining a power supply and an awakening signal supplied by the DCDC, meanwhile, the BCU supplies power to the BMU to enable the BMU to normally work, and at the moment, the DCDC, the BCU and the BMU interact through CAN communication information; and the BCU controls whether the temperature control module works or not according to the detected temperature signal.
When the BCU, the BMU and the DCDC stably work, the BCU detects the ambient temperature and the BMU detects the temperature of the power battery, and when the difference value between the temperature of the power battery and the ambient temperature is lower than a software set threshold and the temperature of the power battery is lower than a software set value, the BCU enters a heating process according to the software setting to preheat the power battery pack; when the difference value between the temperature of the power battery and the ambient temperature is higher than the software set threshold value and the temperature of the power battery is higher than the software set value, the BCU controls the heating to stop; and setting a next self-awakening period for the DCDC, disconnecting the control for awakening the DCDC and keeping the normal output of the DCDC, stopping the output of the DCDC after the DCDC does not have the control, and enabling the whole system to enter a power-off or sleep state to wait for the next start.
The BMS CAN set DCDC self-starting time to the DCDC through the CAN message; BCU is set in a driving or charging state or the set self-starting time is sent through a remote terminal, so that starting can be carried out according to the set time.
In fig. 2 the whole frame thereof comprises: a power lithium battery pack [ which contains a bmu (battery management unit) and a heating device for heating the battery ], a bcu (battery control unit), a DCDC, a switch, a relay, a fuse, a diode and the like, as shown in fig. 2.
Power and control aspects:
the power supply of the low-voltage anode of the BCU is formed by connecting two power supply anodes in parallel, one power supply anode is a lead storage battery anode of the whole vehicle and is controlled by a switch, and the other power supply anode is a low-voltage power supply anode which is connected with a fuse and is converted by DCDC. Two diodes are used for isolating the two paths of power supplies to form mutual noninterference and prevent series connection. And the output anode of the low-voltage power supply of the DCDC not only supplies power to the BCU, but also is connected with the enable awakening pin of the BCU in parallel, and simultaneously awakens the BCU. The low-voltage negative electrode of the BCU is also formed by connecting two power supply negative electrodes in parallel, one power supply negative electrode is a lead storage battery negative electrode of the whole vehicle, the other power supply negative electrode is a low-voltage power supply negative electrode which is connected with a fuse through DCDC conversion after the power battery output is connected with the fuse, and the two power supply negative electrodes are directly connected in parallel to establish a common potential reference point.
2. The BMU in the power lithium battery pack is powered by the BCU. The positive electrode output of the power battery is connected with the fuse and then connected with the main contact of the heating relay, and finally connected with the positive electrode of the heating device, the negative electrode of the heating relay can be directly connected with the negative electrode of the power battery, and a control device can be added according to needs, wherein all the control devices (such as relays) are switched on and off by a BCU (body control unit) according to software setting conditions.
And 3, connecting the high-level driver of the BCU with a wake-up interface of the DCDC, and waking up the DCDC.
The BCU detects the ambient temperature, and the BMU detects the voltage and the temperature of the battery in the power battery pack.
In the aspect of communication:
and 1, carrying out information interaction between the BCU and the BMU as well as between the BCU and the DCDC through the internal CAN.
The working principle of the application comprises:
1. driving state of vehicle
Driving state (discharge): when the vehicle runs, the whole vehicle is powered by lead acid, the switch is turned on, the BMS is powered by the whole vehicle, and meanwhile, the KEYON signal is activated, and the BMS works. Since the KEYON signal on the DCDC is active, the DCDC does not output a low voltage. The BMS may set the DCDC self-start time to the DCDC through the CAN message.
2. Vehicle state of charge
Fill electric pile A + and awaken up DCDC, DCDC gives BMS low voltage power supply, and A + awakens up BMS simultaneously, and DCDC exports its operating condition to BMS through the CAN message after the work, and DCDC controls its operating condition by BMS's CAN message and high flat drive and A + signal etc. simultaneously this moment
BMS power supply for simultaneous A + and DCDC as wake-up signal
BMS CAN set DCDC self-starting time to DCDC through CAN message
3. Vehicle parking state
At this time, the BCU is in a power-off or sleep state, and the BMU is in a power-off or sleep state. The DCDC is in a dormant state, but when the DCDC reaches self-awakening time (BCU setting in a driving or charging state), the DCDC starts and outputs a low-voltage power supply, the BCU normally works after obtaining a power supply and an awakening signal supplied by the DCDC, and meanwhile, the BCU supplies power to the BMU to enable the BMU to normally work. At the moment, the DCDC, the BCU and the BMU exchange information through CAN communication information.
And after the BCU, the BMU and the DCDC stably work, the BCU detects the ambient temperature and the BMU detects the temperature of the power battery.
If the difference value between the power battery temperature and the environment temperature is lower than the software set threshold value, and the power battery temperature is lower than the software set value. The BCU enters a heating process according to software setting to preheat the power battery pack. And when the difference value between the power battery temperature and the ambient temperature is higher than the software set threshold and the power battery temperature is higher than the software set value along with the rise of the battery temperature. The BCU will control the heating to stop. And setting a next self-awakening period for the DCDC, disconnecting the control for awakening the DCDC and keeping the normal output of the DCDC, stopping the output of the DCDC after the DCDC does not have the control, and enabling the whole system (DCDC, BCU and BMU) to enter a power-off or sleep state to wait for the next start.
Compared with the prior art, the technical scheme of the patent has the main characteristics that the heating process of the battery in the prior art can be carried out only when the vehicle is driven or charged, and the prior art prolongs the vehicle heating time during driving/charging. In the application of the scheme, the DCDC can set the self-starting period as required, so that the BCU can work through a power supply provided by the DCDC, collect the temperature and the ambient temperature of the battery, and automatically start and stop heating the battery pack before the vehicle drives/charges according to the threshold set by software. Compared with the prior scheme, the method has the following advantages:
the BCU heats the battery in a low-temperature environment, and preheating is automatically completed at the moment, so that the power lithium battery can immediately exert the maximum performance when a user normally uses the vehicle.
When the BCU is automatically started to preheat, the working electric energy of the BCU is derived from a power lithium battery (through DCDC conversion), and the electricity shortage of the lead storage battery of the whole vehicle is avoided.
The parameter setting of the autonomous heating can be set along with software, and the technology is flexible. And this patent scheme can increase except that the other applications of heating, can optimize the scheme, can increase except that detecting battery system state, battery preheating etc. in waking up certainly, can also increase a series of application schemes such as battery cooling, battery equilibrium, trigger fire control.
It is clear that the specific implementation of the invention is not restricted to the above-described embodiments, but that various insubstantial modifications of the inventive process concept and technical solutions are within the scope of protection of the invention.