Charging control method for pure electric dump truck in cold region

Abstract

A charging control method for a pure electric dumper in a cold region comprises the steps of dynamically adjusting an SOC charging target value according to local air temperature, battery system temperature, characteristics of a battery system and vehicle operation time arrangement for a charging vehicle in the cold region, and ensuring that the battery system temperature is within a normal temperature range when the vehicle starts to operate; and meanwhile, the SOC value of the battery is also within the set target SOC value range. The problem of power failure of a power battery caused by temperature drop of a vehicle battery and heating of the battery when a driver needs to drive in a cold region in winter can be effectively avoided; in addition, the problem that effective operation time of the vehicle is affected by battery heating is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of dump trucks, and in particular to a charging control method for a pure electric dump truck in cold regions. Background Art

[0002] Pure electric dump trucks are operating in mining areas. Since many of the current scenarios involve heavy-load downhill driving, in order to ensure that the vehicle still has the electric braking function after charging is completed and to improve the safety of the vehicle when it is heavily loaded downhill, many mining areas require that the vehicle not be fully charged. Generally, the battery power will be charged to a SOC value between 80-94%.

[0003] Mining operations typically operate in shifts, and pure electric vehicles operate at fixed times and locations. Vehicles are typically charged between shifts, and drivers often have to wait for a while after charging before they can be driven to work. This is especially true when switching from night to day shifts, where the wait time after charging is often quite long.

[0004] Currently, the charging termination level for pure electric dump trucks is typically set uniformly on the charging station. Once the charge reaches the target level, the charging station stops charging. In cold northern winter regions, if a pure electric dump truck waits for an extended period after charging, the battery's temperature drops rapidly. By the time the driver is ready to start the operation, the battery's temperature has already fallen below its normal operating temperature, requiring heating. At this point, the battery enters self-heating mode, causing the charge level to drop below the set target SOC value.

[0005] In cold northern winters, if a pure electric dump truck waits a long time after charging before operating, the battery temperature drops and needs to be heated, resulting in a serious power loss problem, affecting subsequent driving range. Furthermore, the battery heating process takes a certain amount of time, which reduces the vehicle's effective operating time and thus affects vehicle production. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a charging control method for a pure electric dump truck in cold regions. By dynamically adjusting the SOC target value, the problem of power failure caused by heating power consumption in pure electric dump trucks in cold regions and the problem of battery heating affecting the effective operation time of the vehicle are solved.

[0007] To solve the above technical problems, the technical solution of the present invention is: a charging control method for a pure electric dump truck in cold regions, comprising the following steps: (1) After the battery is charged to the SOC target value required before operation; (2) The BMS determines the battery temperature drop rate based on the current outdoor temperature, the battery initial temperature, and the statistical data in the database. At the same time, the VCU determines the waiting time of the vehicle based on the vehicle scheduling and sends the waiting time to the BMS. (3) The BMS calculates the battery temperature when the vehicle starts operating based on the vehicle waiting time and the battery temperature drop rate; (4) Determine whether the temperature value is within the normal operating temperature range of the battery. If so, stop charging. If not, calculate the amount of heat required for the battery to reach the normal operating temperature based on the difference between the calculated battery temperature when the vehicle starts operating and the normal operating temperature of the battery, as well as the mass and specific heat capacity of the battery system itself; (5) Calculate the amount of additional charging required based on the calculated heat and the heating efficiency and heat exchange efficiency of the battery heating system itself; (6) If the additional charge power plus the current battery charge exceeds the full battery charge, the target value of this charge is set to charge to SOC100%. If not, the target SOC value is calculated based on the additional charge power plus the current battery charge. Charging ends when the target value is reached.

[0008] As an improvement, data on battery temperature changes over time at different outdoor temperatures and different battery initial temperatures in the mining area when pure electric vehicles in cold regions are parked outdoors and the power batteries are in a non-working state are collected. Through data statistics, the battery temperature drop rate data corresponding to different temperature differences between outdoor temperature and battery temperature are determined, and the data are imported.

[0009] As an improvement, after the vehicle is charged, the BMS monitors the battery temperature. When the battery system temperature is lower than the minimum temperature point for normal operation, the battery system starts heating. When the battery system SOC value reaches the set SOC value for normal vehicle operation, the battery stops heating. If the battery temperature reaches the alarm temperature, heating will also stop.

[0010] The beneficial effects brought about by the present invention compared with the prior art are: For vehicles charging in cold regions, the SOC charging target value is dynamically adjusted based on local temperature, battery system temperature, battery system characteristics, and the vehicle's operating schedule. This ensures that the battery system temperature is within the normal temperature range and the battery SOC value is within the set target SOC value range when the vehicle begins operating. This effectively prevents the battery temperature from dropping when drivers in cold winter regions need to operate the vehicle, requiring heating, which could lead to power battery loss. It also prevents battery heating from affecting the vehicle's effective operating time. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1Control flow chart after charging the battery to the SOC target value required before operation.

[0012] Figure 2 Control flow chart after vehicle charging is completed. DETAILED DESCRIPTION

[0013] The present invention will be further described below with reference to the accompanying drawings.

[0014] The battery temperature change data over time at different outdoor temperatures and different battery initial temperatures in the mining area are collected when the pure electric vehicles in cold regions are parked outdoors and the power batteries are in a non-working state (neither charging nor discharging). Through data statistics, the battery temperature drop rate (in ℃ / h) corresponding to different temperature differences between the outdoor temperature and the battery temperature is determined, and the data is imported into the battery control system BMS.

[0015] like Figure 1 As shown, after the battery is charged to the required SOC target value before operation, the BMS determines the battery temperature drop rate based on the current outdoor temperature, the initial battery temperature, and statistical data from the database. At the same time, the VCU determines the vehicle's waiting time based on the vehicle's scheduled operation and sends the waiting time to the BMS. The BMS calculates the battery temperature when the vehicle starts operating based on the vehicle's waiting time and the battery temperature drop rate. It determines whether the temperature is within the battery's normal operating temperature range. If so, charging is stopped. If not, the heat required to reach the normal operating temperature is calculated based on the difference between the calculated battery temperature when the vehicle starts operating and the battery's normal operating temperature, as well as the mass and specific heat capacity of the battery system itself. The additional charging amount is calculated based on the calculated heat and the heating efficiency and heat exchange efficiency of the battery heating system itself. If the additional charging amount plus the current battery charge exceeds the battery's full charge, the target value for this charge is set to charge to 100% SOC. If not, the target SOC value is calculated based on the additional charging amount plus the current battery charge. Charging ends when the target SOC value is reached.

[0016] like Figure 2 As shown, after the vehicle is charged, the BMS monitors the battery temperature. When the battery system temperature is lower than the minimum temperature point for normal operation, the battery system starts heating. When the battery system SOC value reaches the set SOC value for normal vehicle operation, the battery stops heating. If the battery temperature reaches the alarm temperature, heating will also stop.

[0017] This invention, specifically designed for charging vehicles in cold regions, dynamically adjusts the SOC charging target value based on local air temperature, battery system temperature, the characteristics of the battery system itself, and the vehicle's operating schedule. This ensures that when the vehicle begins operating, the battery system temperature is within the normal temperature range and the battery SOC value is within the set target SOC value range. This effectively prevents the problem of battery temperature dropping and the need for heating when drivers in cold winter regions need to operate the vehicle, leading to power battery loss. It also prevents battery heating from affecting the vehicle's effective operating time.

Claims

1. A charging control method for a pure electric dump truck in cold regions, characterized in that: The following steps are involved: (1) After the battery is charged to the SOC target value required before operation; (2) The BMS determines the battery temperature drop rate based on the current outdoor temperature, the battery initial temperature, and the statistical data in the database. At the same time, the VCU determines the waiting time of the vehicle based on the vehicle scheduling and sends the waiting time to the BMS. (3) The BMS calculates the battery temperature when the vehicle starts operating based on the vehicle waiting time and the battery temperature drop rate; (4) Determine whether the temperature value is within the normal operating temperature range of the battery. If so, stop charging. If not, calculate the amount of heat required for the battery to reach the normal operating temperature based on the difference between the calculated battery temperature when the vehicle starts operating and the normal operating temperature of the battery, as well as the mass and specific heat capacity of the battery system itself; (5) Calculate the amount of additional charging required based on the calculated heat and the heating efficiency and heat exchange efficiency of the battery heating system itself; (6) If the additional charge power plus the current battery charge exceeds the full battery charge, the target value of this charge is set to charge to SOC100%. If not, the target SOC value is calculated based on the additional charge power plus the current battery charge. Charging ends when the target value is reached.

2. The cold region charging control method for a pure electric dump truck according to claim 1, characterized in that: The data on battery temperature changes over time at different outdoor temperatures and different battery initial temperatures in the mining area when pure electric vehicles in cold regions are parked outdoors and the power batteries are in a non-working state are collected. Through data statistics, the battery temperature drop rate data corresponding to different temperature differences between outdoor temperature and battery temperature are determined and imported.

3. The cold region charging control method for a pure electric dump truck according to claim 1, characterized in that: After the vehicle is charged, the BMS monitors the battery temperature. When the battery system temperature is lower than the minimum temperature point for normal operation, the battery system starts heating. When the battery system SOC value reaches the set SOC value for normal vehicle operation, the battery stops heating. If the battery temperature reaches the alarm temperature, heating will also stop.

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