CN202906510U - Electric vehicle charging pile - Google Patents

Abstract

The utility model provides a charging pile for electric vehicles, the charging pile includes a control unit, an energy storage module, a communication module, an energy scheduling module and an output interface, and the control unit controls and connects the communication module, the energy scheduling module and the output interface , the energy storage module and the energy scheduling module are connected to each other; the energy storage module stores electric energy; the communication module communicates with the distribution network system and accepts instructions from the distribution network system, and the distribution network system The instruction includes the load condition of the power grid; the energy dispatch module determines the power supply source of the charging pile according to the load condition of the power grid, the energy storage module and user demand; the output interface determines the power supply source according to the energy dispatch module The power provided by the grid or the grid and the energy storage module is output to the user's electric vehicle.

Description

An electric vehicle charging pile

technical field

The utility model relates to the technical field of electric vehicle charging and swapping, in particular to an electric vehicle charging pile.

Background technique

Electric vehicles, especially pure electric vehicles, use electricity as energy, have the advantages of low emissions and high energy efficiency, and are the main choice to replace fuel vehicles. In the context of increasingly prominent global energy and environmental problems, the development of electric vehicles has become an important way to get rid of dependence on oil resources, achieve energy conservation and emission reduction, and alleviate energy and environmental problems. One of the core technologies of electric vehicles is the energy storage and supply system. The use of batteries and rapid replacement technology and electric vehicle charging and swapping station technology have become the key technologies for the industrialization of electric vehicles.

Some difficulties and problems in the construction of service network infrastructure such as charging and swapping stations in the existing technology have increasingly restricted the construction of the entire operation service network. The problems in the existing technology include: 1. Urban land shortage, electric vehicles The construction of charging and swapping stations is faced with the problem of how to reduce the occupied area as much as possible, increase the effective use area, and optimize the planning of electric vehicle service network; 2. The construction of electric vehicle charging and swapping stations needs to go through the preliminary planning and site selection, land acquisition and approval, and the mid-term foundation The three basic stages of building construction, equipment installation and commissioning in the later stage, the overall construction cycle takes a long time; 3. The power battery of electric vehicles is subject to operating environmental factors, and the battery charging and storage environment of the charging and swapping stations currently under construction is not ideal. Good constant temperature, low humidity, ventilation and dust-proof effects have not yet been achieved. The power battery has been in a relatively open environment for a long time, and is easily affected by seasonal factors and vehicle damage. The service life is short, and the charging and discharging efficiency is unstable.

Utility model content

The utility model provides a charging pile for electric vehicles. The charging pile includes a control unit, an energy storage module, a communication module, an energy scheduling module and an output interface. The control unit controls and connects the communication module, the energy scheduling module and the output interface. interface, the energy storage module and the energy scheduling module are connected to each other; the energy storage module stores electric energy; the communication module communicates with the distribution network system and accepts the instructions of the distribution network system, and the distribution network The order of the system includes the load condition of the grid; the energy dispatching module determines the power supply source of the charging pile according to the grid load condition, the energy storage module condition and the user demand; the output interface determines the power supply source according to the energy dispatching module Output the power provided by the grid or the grid and the energy storage module to the user's electric vehicle.

In the first preferred embodiment provided by the utility model: the communication module includes a GPRS interface, supports TCP/IP Ethernet interface, CAN bus communication interface, PLC communication interface, Zigbee bus communication interface and 3G, 4G wireless communication interface.

In the second preferred embodiment provided by the utility model: the charging pile includes a billing and metering module and a card swiping module;

The billing and metering module includes an energy storage module energy billing module and an electric vehicle charging energy billing module;

The energy billing module of the energy storage module is used to charge the energy of the energy storage module when the energy storage module participates in the charging work;

The electric vehicle charging energy billing module is used to charge the energy charged by the user's electric vehicle according to the energy storage module energy billing module and the power consumption of the grid;

The card swiping module is used to identify the identity of the user's electric vehicle when the user's electric vehicle starts charging, and settle the charge for the energy charged by the electric vehicle calculated by the billing and metering module after the charging is completed.

In the third preferred embodiment provided by the utility model: the charging pile includes a man-machine interface module;

The man-machine interface module includes a display screen, and the display screen shows the information of charging process voltage, power and current, charging time and charging cost to the user.

In the fourth preferred embodiment provided by the utility model: the charging pile includes a charging process protection module, and the charging process protection module performs leakage protection and overcurrent protection for the charging pile and the user's electric vehicle.

In the fifth preferred embodiment provided by the utility model: the energy storage module is used to use the power grid or solar energy to store electric energy when the power grid is at a low point, and includes a charge and discharge control unit, a photovoltaic power generation module, a PWM module, and a DC/DC module A , a DC/DC module B and an energy storage unit, the energy scheduling module is connected to the charge and discharge control unit, the energy storage unit and the DC/DC module A;

One end of the DC/DC module A is connected to the photovoltaic power generation module, and the other end is connected to an energy storage unit or an energy dispatching module;

The charging and discharging control unit controls and connects the PWM module and the DC/DC module B, and one end of the DC/DC module B is connected to the PWM module, and the other end is connected to the energy storage unit.

In the sixth preferred embodiment provided by the utility model: the capacity Q of the power lithium battery is:

Among them, U _2l is the voltage of the power battery on the vehicle, t is the charging time, h is the correction value of the charging time, U _1l is the terminal voltage of the energy storage module corresponding to the SOC of the energy storage battery being 15%;

The capacitance C of the supercapacitor is:

$\mathrm{<span\; class="notranslate">\; C</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; [</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; UI</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&Delta;I</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; \&Delta;I</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span>}{{\mathrm{<span\; class="notranslate">\; u</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}$

为恒压阶段等分的小的时间段的份数，t为恒压阶段总时长。Among them, U ₂ is the terminal voltage of the power battery when the constant current stage changes to the constant voltage stage during the charging process, U ₁ is the starting voltage of the power battery charging, I is the current value in the constant current stage, ΔI is the step size of the current drop in the constant voltage process, t ₁ is the constant current charging time, Δt is the time corresponding to the current drop ΔI,

is the number of small time periods equally divided in the constant pressure stage, and t is the total duration of the constant pressure stage.

The beneficial effects of an electric vehicle charging pile provided by the utility model include:

1. The electric vehicle charging pile provided by the utility model, the charging pile includes an energy storage module and a communication module, is controlled and managed by the same management platform, accepts the instructions of the distribution network system, and does not meet the charging requirements of electric vehicles due to grid reasons , the energy storage module can be used to charge the user's electric vehicle and actively participate in the friendly interaction with the power grid.

2. The charging pile also includes an energy scheduling module, which determines the source of electric energy supply for the charging pile according to the grid load, the energy storage module, and the user's needs.

3. The energy storage module can use the power grid or solar energy to store electric energy when the power grid is at a low point.

4. The charging pile includes a billing and metering module, a card swiping module, a man-machine interface module and a charging process protection module. The billing and metering module is used to bill the energy charged by the user's electric vehicle, and the card swiping module is used to verify the identity of the user's electric vehicle. Identify and settle the energy charge of the electric vehicle after charging; the man-machine interface module displays information such as voltage, power and current, charging time, charging cost and other information during the charging process to the user; the protection module performs leakage protection and over-current protection during the charging process Protect.

Description of drawings

Fig. 1 is a schematic structural diagram of a charging pile provided by the present invention;

Fig. 2 is a schematic structural diagram of an embodiment of a charging pile provided by the present invention;

Fig. 3 is a method flowchart of a charging pile operation method provided by the present invention;

Fig. 4 is the flowchart of charging the user's electric vehicle by the energy storage module provided by the present invention;

Fig. 5 is a flow chart of charging the energy storage module provided by the present invention.

Detailed ways

An electric vehicle charging pile provided by the utility model, the structural diagram of the charging pile is shown in Figure 1, including a control unit, an energy storage module, a communication module, an energy scheduling module and an output interface. The control unit controls the connection of the communication module, the energy The scheduling module and the output interface, the energy storage module and the energy scheduling module are connected to each other.

The energy storage module stores electrical energy.

The communication module communicates with the distribution network system, and accepts the order of the distribution network system, and the order of the distribution network system includes the load condition of the power grid.

The energy dispatching module determines the source of electric energy supply for the charging pile according to the load condition of the grid, the condition of the energy storage module and the user's demand.

The output interface outputs the power provided by the grid or the grid and the energy storage module to the electric vehicle according to the power supply source determined by the energy scheduling module.

Embodiment one:

Embodiment 1 provided by the utility model is an embodiment of an electric vehicle charging pile. The structural diagram of the embodiment of the charging pile is shown in Figure 2, including a control unit, an energy storage module, a communication module, an energy scheduling module, an output Interface, billing and metering module, card swiping module, man-machine interface module and charging process protection module, the control unit controls the connection communication module, energy dispatching module, output interface, billing and metering module, card swiping module, man-machine interface module and charging process protection module, the energy storage module and the energy scheduling module are connected to each other.

The communication module includes GPRS interface, supports TCP/IP Ethernet interface, CAN bus communication interface, PLC (Programmable Logic Controller, programmable logic controller) communication interface, Zigbee bus communication interface and 3G, 4G wireless communication interface.

The billing and metering module includes the energy billing module of the energy storage module and the charging energy billing module of the electric vehicle. The energy billing module of the energy storage module is used to bill the energy of the energy storage module when the energy storage module participates in the charging work. The electric vehicle charging energy billing module is used to charge the electric vehicle charging energy according to the energy storage module energy billing module and the power consumption of the grid.

The card swiping module is used to identify the identity of the charging user when the user starts charging, and settle the charge for the energy charged by the electric vehicle calculated by the billing and metering module after the charging is completed.

The man-machine interface module includes a display screen, which displays information such as voltage, power and current during charging, charging time, charging cost, etc. to the user.

The charging process protection module performs leakage protection and overcurrent protection for charging piles and charging electric vehicles.

The energy storage module includes charge and discharge control unit, photovoltaic power generation module, PWM (Pulse Width Modulation, pulse width modulation) module, DC/DC module A, DC/DC module B and energy storage unit, energy dispatching module and charge and discharge control unit, The energy storage unit is connected to DC/DC module A.

The energy storage module is used to use the power grid or use solar energy to store electric energy when the power grid is at a low point. into the energy storage unit for storage. The charging and discharging control unit controls the connection between the PWM module and the DC/DC module B, and the electric energy transmitted to the energy storage module at the time of the power grid's low valley is converted into DC by the PWM module, and the fixed DC voltage is converted into a variable by the DC/DC module B. The DC voltage is sent to the energy storage unit for storage.

The energy storage unit includes a power battery and a super capacitor to realize the secondary utilization of the power battery. Among them, the power battery is a power lithium battery, and the capacitance C of the supercapacitor is:

$\mathrm{<span\; class="notranslate">\; C</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; [</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; UI</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&Delta;I</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; \&Delta;I</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span>}{{\mathrm{<span\; class="notranslate">\; u</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}$

为恒压阶段等分的小的时间段的份数，t为恒压阶段总时长。Among them, U ₂ is the terminal voltage of the power battery when the constant current stage changes to the constant voltage stage during the charging process, U ₁ is the starting voltage of the power battery charging, I is the current value in the constant current stage, ΔI is the step size of the current drop in the constant voltage process, t ₁ is the constant current charging time, Δt is the time corresponding to the current drop ΔI,

is the number of small time periods equally divided in the constant pressure stage, and t is the total duration of the constant pressure stage.

The capacity Q of the power lithium battery is: $Q=\frac{u_{2l}I(t+h)}{u_{1l}}\&Center\; Dot;$

Where U _2l is the voltage of the power battery on the vehicle, t is the charging time, h is the correction value of the charging time, and U _1l is the terminal voltage of the energy storage module (the voltage corresponding to the SOC of the energy storage battery being 15%).

Embodiment two:

Embodiment 2 provided by the utility model is an operation method of the charging pile provided by the utility model. The charging pile is controlled and managed by the same management platform. When the user's electric vehicle is supplied with electric energy, when the grid load is large, the user's electric vehicle can be charged through the energy storage module. The flow chart of this operation method is shown in Figure 3, including:

In step S1, the charging pile starts charging according to the charging demand of the user's electric vehicle.

Step S2, judging whether an instruction from the distribution network system has been received, if yes, execute step S3, if no, use the electric energy of the grid to directly charge the user's electric vehicle according to the charging demand of the user's electric vehicle.

When the grid load is large, the distribution network system issues instructions to the charging piles, which include the load that the current grid can provide.

Step S3, calculate the load difference, the load difference is the difference between the charging demand of the user's electric vehicle and the load that the grid can provide, and judge whether the load difference is a positive value, if yes, go to step S4, if no, according to the user's electric vehicle The charging demand uses the electric energy of the grid to directly charge the user's electric vehicle.

Step S4, determining the discharge current of the energy storage module according to the rated power of the on-board charger and the acceptable DC discharge rate of the energy storage module.

Preferably, after determining the starting time point of the energy storage module as the charging power source in step S4, the flow chart of the energy storage module charging the user's electric vehicle is shown in Figure 4, including:

Step S401, when the initial time point when the energy storage module is used as the charging power source is reached, it is judged whether the SOC (state of charge, state of charge, the ratio of the remaining capacity of the battery to the capacity of the fully charged state) of the power battery of the energy storage module is If it is greater than the suggested value, if yes, go to step S402; if no, go to step S403.

Setting the SOC value of the power battery to be greater than the recommended value is to avoid deep discharge of the battery and prolong the life of the energy storage battery. Preferably, the suggested value is 15%.

Step S402, the energy storage module charges the user's charging car until the charging process ends, and continuously judges whether the SOC value of the power battery is greater than the recommended value during the charging process. Once the SOC value of the power battery is not greater than the recommended value, step S403 is executed.

Preferably, in step S402, the energy storage module charges the charging car of the user and at the same time detects whether the power grid is in the peak period at this time. If it is in the peak period, stop the energy storage charging and use the power grid for charging. During the peak load, the energy storage module is used to charge. Make the user use grid power for charging as much as possible, reduce the energy consumed during energy storage and release, and at the same time reduce the number of charging and discharging of the power battery as much as possible, and increase the battery life.

Step S403, judging whether the user's electricity demand is currently met, and if not, apply to the superior monitoring system for AC charging of the user's electric vehicle by the power grid.

Embodiment 2 of the utility model provides a charging pile operation method. If the charging demand of the user's electric vehicle is greater than the load value that the power grid can provide at this moment when the charging task is started, the user's electric vehicle is charged through the energy storage module, and Calculate the starting time point when the energy storage module is used as a charging power source.

When the starting time point of the energy storage module as the charging power source is reached, if the energy storage module cannot charge the user's electric vehicle at this time, and because the load of the power grid changes in real time, it is necessary to judge whether the current power consumption of the user is reached. If necessary, if the user's electricity demand has not been met at this time, apply to the superior monitoring system for AC charging of the user's electric vehicle.

If the user's electricity demand has been met, because the current SOC value of the energy storage module is lower than the recommended value, the user's electric vehicle cannot be charged, so step S5 is also included to charge the energy storage module.

The process of charging the energy storage module in step S5 is shown in Figure 5, including:

Step S501, determine whether the photovoltaic power generation module can work, if yes, execute step S502, if no, charge the energy storage module through the grid when the grid load allows charging the energy storage module, execute step S504.

The photovoltaic power generation module is connected to the energy storage unit and the energy dispatching module, and when the external environment meets the working conditions, it can start to store energy on the energy storage unit or directly charge the user's electric vehicle.

Step S502, determine whether the grid is charging the energy storage module, and if so, stop the grid from charging the energy storage module, and execute step S503.

Step S503, start the photovoltaic power generation module to charge the energy storage module, and execute step S504.

Step S504, stop charging when the energy storage requirement of the energy storage module is met.

During the operation of the charging pile, the energy storage status of the energy storage module will also be monitored in real time, and the energy storage module will be charged when the energy storage module does not meet the energy storage requirements. Therefore, before the above step S501, it also includes:

Step S501', judge in real time whether the energy storage module meets the energy storage requirements, and execute step S501 if not.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present utility model and not to limit them. Although the present utility model has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: it is still possible Any modification or equivalent replacement made to the specific implementation of the present utility model without departing from the spirit and scope of the present utility model shall be covered by the claims of the present utility model.

Claims (7)

1. An electric vehicle charging pile, characterized in that the charging pile includes a control unit, an energy storage module, a communication module, an energy scheduling module and an output interface, and the control unit controls and connects the communication module, the energy scheduling module and the an output interface, the energy storage module is connected to the energy scheduling module; The energy storage module stores electric energy; The communication module communicates with the distribution network system, and accepts the instructions of the distribution network system, and the instructions of the distribution network system include the grid load condition; The energy dispatching module determines the source of electric energy supply of the charging pile according to the load condition of the grid, the condition of the energy storage module and the user demand; The output interface determines the source of electric energy supply according to the energy scheduling module, and outputs the power provided by the grid or the grid and the energy storage module to the electric vehicle of the user. 2. The charging pile according to claim 1, wherein the communication module includes a GPRS interface, supports TCP/IP Ethernet interface, CAN bus communication interface, PLC communication interface, Zigbee bus communication interface and 3G, 4G wireless Communication Interface. 3. The charging pile according to claim 1, characterized in that, the charging pile includes a billing and metering module and a card swiping module; The billing and metering module includes an energy storage module energy billing module and an electric vehicle charging energy billing module; The energy storage module energy billing module is used to charge the energy of the energy storage module when the energy storage module participates in the charging work; The electric vehicle charging energy billing module is used to charge the energy charged by the user's electric vehicle according to the energy storage module energy billing module and the power consumption of the grid; The card swiping module is used to identify the identity of the user's electric vehicle when the user's electric vehicle starts charging, and settle the charge for the energy charged by the electric vehicle calculated by the billing and metering module after the charging is completed. 4. The charging pile according to claim 1, characterized in that, the charging pile includes a man-machine interface module; The man-machine interface module includes a display screen, and the display screen shows the information of charging process voltage, power and current, charging time and charging cost to the user. 5. The charging pile according to claim 1, characterized in that, the charging pile includes a charging process protection module, and the charging process protection module performs leakage protection and overcurrent protection for the charging pile and the user's electric vehicle . 6. The charging pile according to claim 1, characterized in that, the energy storage module is used to use the power grid or solar energy to store electric energy when the power grid is at a low point, and includes a charge and discharge control unit, a photovoltaic power generation module, a PWM module, a DC /DC module A, DC/DC module B and energy storage unit, the energy scheduling module is connected to the charge and discharge control unit, energy storage unit and DC/DC module A; One end of the DC/DC module A is connected to the photovoltaic power generation module, and the other end is connected to an energy storage unit or an energy dispatching module; The charging and discharging control unit controls and connects the PWM module and the DC/DC module B, and one end of the DC/DC module B is connected to the PWM module, and the other end is connected to the energy storage unit. 7. The charging pile according to claim 6, wherein the energy storage unit includes a power battery and a super capacitor, and the power battery is a power lithium battery; The capacity Q of the power lithium battery is: $Q=\frac{u_{2l}I(t+h)}{u_{1l}}\&Center\; Dot;$ Among them, U _2l is the voltage of the power battery on the vehicle, t is the charging time, h is the correction value of the charging time, U _1l is the terminal voltage of the energy storage module corresponding to the SOC of the energy storage battery being 15%; The capacitance C of the supercapacitor is: $\mathrm{<span\; class="notranslate">\; C</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; [</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; UI</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&Delta;I</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; \&Delta;I</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span>}{{\mathrm{<span\; class="notranslate">\; u</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}$ Among them, U ₂ is the terminal voltage of the power battery when the constant current stage changes to the constant voltage stage during the charging process, U ₁ is the starting voltage of the power battery charging, I is the current value in the constant current stage, ΔI is the step size of the current drop in the constant voltage process, t ₁ is the constant current charging time, Δt is the time corresponding to the current drop ΔI,

is the number of small time periods equally divided in the constant pressure stage, and t is the total duration of the constant pressure stage.

Images