Environmentally friendly vehicle and charging control method thereof

Abstract

The present invention relates to an environmentally friendly vehicle and a charging control method thereof. An environmentally friendly vehicle using a charging control method improves wireless charging efficiency and effectively manages charging / discharging of a battery of the vehicle. The environmentally friendly vehicle includes: a wireless power receiver for wirelessly receiving power from an external charging device; a memory for storing status information of each of a plurality of battery cells; and a controller for controlling a charging sequence of each of a plurality of battery cells by using the status information stored in the memory when an engine of the vehicle is in an off state.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2019-0093780, filed on August 1, 2019, which is hereby incorporated by reference in its entirety. Technical Field

[0003] The present disclosure relates to a vehicle, and more particularly, to an environmentally friendly vehicle that operates using electric energy supplied by a battery. Background Art

[0004] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

[0005] As the supply of environmentally friendly vehicles increases, many environmentally friendly vehicle manufacturers have developed various battery charging methods for the environmentally friendly vehicles.

[0006] Among battery charging methods for eco-friendly vehicles, wireless charging technology has attracted widespread attention. Instead of the conventional method of charging devices and eco-friendly vehicles through cables, wireless charging technology is developed for eco-friendly vehicles. Wireless charging technology wirelessly transmits power in the form of RF signals to charge the batteries of eco-friendly vehicles.

[0007] As a wireless charging technology, a wireless charging system using the magnetic induction phenomenon is used. It has been found that the magnetic induction method, which induces current from one coil to another through a magnetic field, is sensitive to the distance and relative position between the coils, and has poor charging efficiency due to external noise. Summary of the invention

[0008] The present disclosure improves the wireless charging efficiency of an environmentally friendly vehicle and also effectively manages the charging / discharging of a battery.

[0009] According to one aspect of the present disclosure, an environmentally friendly vehicle includes: a wireless power receiver configured to wirelessly receive power from an external charging device; a memory configured to store status information of each of a plurality of battery cells; and a controller configured to control a charging order of battery cells among the plurality of battery cells using the status information stored in the memory when an engine of the environmentally friendly vehicle is in an off state.

[0010] In one form, the controller is configured to set a charging order of battery cells among the plurality of battery cells based on a state of charge (SOC) of each battery cell, and to set a higher priority in the charging order to a battery cell having a lower SOC among the plurality of battery cells.

[0011] In another form, the environmentally friendly vehicle further includes: a plurality of cell balancing units, each of which is provided to a corresponding battery cell in the plurality of battery cells. In particular, the controller sequentially wakes up the battery balancing units in the plurality of battery balancing units based on the charging sequence of the battery cells in the plurality of battery cells, and controls each battery cell to be charged in the plurality of battery cells based on the charging sequence.

[0012] When charging of a battery cell among the plurality of battery cells is completed, the controller stores voltage information of the charged battery cell in a memory.

[0013] In other forms, the controller receives operation information of the wireless power receiver and, when charging of one of the plurality of battery cells is completed, charges another of the plurality of battery cells by resetting the wireless power receiver.

[0014] In another form, the controller receives operation information of the wireless power receiver, and when abnormal operation of the wireless power receiver is detected from the operation information, initializes the wireless power receiver to a normal state by resetting the wireless power receiver.

[0015] In another aspect of the present disclosure, an environmentally friendly vehicle includes: a wireless power receiver configured to wirelessly receive power from an external charging device and including a comparator configured to select a frequency of the received power; a memory configured to store status information of each of a plurality of battery cells; and a controller configured to control the frequency selection of the comparator and control a charging order of the battery cells of the plurality of battery cells using the status information stored in the memory when an engine of the environmentally friendly vehicle is in an off state.

[0016] In another aspect, when the controller controls a charging order of battery cells among a plurality of battery cells, the controller assigns a higher priority to a battery cell having a lower state of charge (SOC).

[0017] In another form, the comparator is configured to select only a band of voltages greater than a threshold voltage; and the controller is configured to variably apply a magnitude of the threshold voltage based on a state of health (SOH) of each of the plurality of battery cells.

[0018] In another form, when a battery cell having 100% SOH among a plurality of battery cells is charged, 100% of a predetermined threshold voltage is applied to the comparator; and when the SOH of a battery cell among the plurality of battery cells is less than 100%, a ratio less than 100% proportional to the SOH of the corresponding battery cell is applied to the comparator.

[0019] The environmentally friendly vehicle may further include: a plurality of battery balancing units, each of which is respectively set to a corresponding battery cell in the plurality of battery cells. In particular, the controller sequentially wakes up the battery balancing units in the plurality of battery balancing units based on the charging sequence of the battery cells in the plurality of battery cells, and controls each battery cell in the plurality of battery cells to be charged based on the charging sequence.

[0020] In one form, when charging of a battery cell among the plurality of battery cells is completed, the controller stores voltage information of the charged battery cell in a memory.

[0021] The controller may be configured to receive operation information of the wireless power receiver, and when charging of one battery cell among the plurality of battery cells is completed, charge another battery cell among the plurality of battery cells by resetting the wireless power receiver.

[0022] In another form, the controller may be configured to receive operation information of the wireless power receiver, and when abnormal operation of the wireless power receiver is detected from the operation information, initialize the wireless power receiver to a normal state by resetting the wireless power receiver.

[0023] In another aspect of the present disclosure, a charging control method for an environmentally friendly vehicle is provided, wherein the vehicle includes: a wireless power receiver for wirelessly receiving power from an external charging device and including a comparator for selecting a frequency of the received power; a memory for storing status information of each battery cell in a plurality of battery cells; and a controller for controlling a charging sequence of the battery cells in the plurality of battery cells. In particular, the method includes: controlling the frequency selection of the comparator by the controller; and when the engine of the vehicle is in an off state, controlling the charging sequence of the battery cells in the plurality of battery cells by the controller using the status information stored in the memory.

[0024] In controlling a charging order of battery cells among a plurality of battery cells, a higher charging priority is assigned to a battery cell having a lower state of charge (SOC).

[0025] In another form, the charging control method further includes: selecting only a band of voltages greater than a threshold voltage by a comparator; and variably applying a magnitude of the threshold voltage based on a state of health (SOH) of each of the plurality of battery cells by a controller.

[0026] When a battery cell having 100% SOH among multiple battery cells is charged, 100% of the predetermined threshold voltage is applied to the comparator; and when the SOH of a battery cell among the multiple battery cells is less than 100%, a ratio less than 100% proportional to the SOH of the battery cell is applied to the comparator.

[0027] The charging control method further includes storing, by the controller, voltage information of the charged battery cell in a memory when charging of one of the plurality of battery cells is completed.

[0028] The charging control method may include receiving operation information of the wireless power receiver, and when charging of one battery cell among the plurality of battery cells is completed, charging another battery cell among the plurality of battery cells by resetting the wireless power receiver.

[0029] The charging control method may include receiving operation information of the wireless power receiver, and when abnormal operation of the wireless power receiver is detected from the operation information, initializing the wireless power receiver to a normal state by resetting the wireless power receiver.

[0030] An aspect of the present disclosure is to improve wireless charging efficiency of an environmentally friendly vehicle and effectively manage charging / discharging of a battery.

[0031] Further areas of applicability will become apparent from the description provided herein.It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order that the present disclosure may be better understood, various forms thereof will now be described, given by way of example, with reference to the accompanying drawings, in which:

[0033] Figure 1 is a diagram showing a wireless charging system for an environmentally friendly vehicle;

[0034] Figure 2 is a diagram showing a wireless power receiver and a battery of an environmentally friendly vehicle;

[0035] Figure 3A , Figure 3B and Figure 3C is a diagram showing a comparator constituting a wireless charging receiver of an environmentally friendly vehicle and a voltage of the comparator;

[0036] Figure 4A , Figure 4B and Figure 4C is a diagram showing voltage characteristics of a wireless power receiver;

[0037] Figure 5 is a diagram illustrating determination of a battery unit charging order of an environmentally friendly vehicle; and

[0038] Fig. 6A and Figure 6B Each is a flowchart showing a battery charging method for an environmentally friendly vehicle.

[0039] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. DETAILED DESCRIPTION

[0040] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate similar or corresponding parts and features.

[0041] Figure 1 is a view showing a wireless charging system for an environmentally friendly vehicle according to one form of the present disclosure.

[0042] The wireless charging device 120 performs power conversion, charging control, charging, etc. The wireless charging device 120 includes a wireless power transmitter 122 buried underground. The wireless charging device 120 wirelessly communicates with the eco-friendly vehicle 100 to perform charging control and charging.

[0043] An environmentally friendly vehicle 100 according to one form of the present disclosure is provided with a battery 140 and a wireless power receiver 142 .

[0044] The battery 140 is charged by power received through the wireless power receiver 142 .

[0045] The wireless power receiver 142 allows the battery 140 to be charged by receiving wireless power that is transmitted in the form of an RF signal by the wireless power transmitter 122 of the wireless charging device 120 to be delivered to the battery 140 .

[0046] Figure 2 is a view showing a wireless power receiver and a battery of an environmentally friendly vehicle according to one form of the present disclosure.

[0047] The wireless power receiver 142 includes a matching circuit 212 , a comparator 214 , a rectifier 216 , and a DC-DC converter 218 .

[0048] The matching circuit 212 is provided to prevent impedance matching and power loss between the wireless power transmitter 122 of the external wireless charging device 120 and the wireless power receiver 142 of the environmentally-friendly vehicle 100. Figure 2 , “P1” is the output voltage of the matching circuit 212 .

[0049] A comparator 214 is provided to receive the output voltage P1 of the matching circuit 212 to increase the voltage and remove noise. Figure 5 The configuration and operation of comparator 214 are described in more detail. Figure 2 , “P2” is the output voltage of the comparator 214 .

[0050] The rectifier 216 receives the output voltage P2 of the comparator 214 and rectifies the AC voltage into a DC voltage. Figure 2 , “P3” is the output voltage of the rectifier 216 .

[0051] The DC-DC converter 218 converts the output voltage P3 of the rectifier 216 into a DC voltage for charging the battery 140. The output voltage of the DC-DC converter 218 is provided to the battery 140 and is used to charge the battery 140.

[0052] The battery 140 includes a charge controller 202 , a plurality of battery balancing units 252 , and a plurality of battery cells 262 .

[0053] The charging controller 202 controls the overall charging of the battery 140 . To this end, the state information of each battery cell in the plurality of battery cells 262 is received from the plurality of battery balancing units 252 and stored in the memory 204 .

[0054] In addition, the charging controller 202 receives operation information of the comparator 214 from the comparator 214 of the wireless power receiver 142, generates a reset signal if necessary, and rarely resets the comparator 214. For example, when charging of one battery cell 262 is completed, the charging controller 202 may reset the comparator 214 to charge another battery cell 262. In addition, when the comparator 214 cannot operate normally, the charging controller 202 may generate a reset signal to hard reset the comparator 214, and then try to charge again.

[0055] By receiving the state information of each of the plurality of battery cells 262 and storing it in the memory 204, in the future, even in the engine-off state of the environmentally-friendly vehicle 100, it is possible to uniformly charge by checking the state (battery balancing) of each of the plurality of battery cells 262. The plurality of battery balancing units 252 acquire the state information of each of the plurality of battery cells 262 and transmit the state information to the charge controller 202, and perform battery balancing of each of the plurality of battery cells 262 under the control of the charge controller 202.

[0056] Cell balancing means managing the charging and discharging of the plurality of battery cells 206, and if possible, evenly charging / discharging all of the plurality of battery cells 262 without biasing any one battery cell.

[0057] Each of the plurality of battery cells 262 is charged and managed by each of the plurality of battery balancing units 252. Each charging of the plurality of battery cells 262 is performed until the voltage of each of the plurality of battery cells 262 reaches the second reference voltage. The second reference voltage may be set differently for each of the plurality of battery cells 262. For example, since the chargeable voltage may be different from each other according to the state of health (SOH) and the state of charge (SOC) of each of the plurality of battery cells 262, charging is performed by changing the second reference voltage of each of the plurality of battery cells.

[0058] Figure 3A , Figure 3B and Figure 3C is a view showing a comparator and a voltage of the comparator constituting a wireless charging receiver for an environmentally friendly vehicle according to one form of the present disclosure.

[0059] like Figure 3A As shown, the comparator 214 receives the output voltage P1 of the matching circuit 212 and compares it with the first reference voltage Vref, and then amplifies the resistor Rfb and the capacitor Cfb when the input voltage P1 is less than the first reference voltage Vref.

[0060] By comparing with the threshold voltage Vth, the voltage 302 amplified by the resistor Rfb and the capacitor Cfb is output only as the output voltage P2 when compared with the threshold voltage, and a voltage less than the threshold voltage Vth is not output.

[0061] Figure 3B 302 is shown as amplified by resistor Rfb and capacitor Cfb. Figure 3C It can be seen that the voltage 304 less than the threshold voltage Vth is not output. Due to this action, the noise component (the portion less than Vth) in the input power including the similarity comparator 214 can be eliminated.

[0062] Figure 4A , Figure 4B and Figure 4C is a diagram showing voltage characteristics of a wireless power receiver according to one form of the present disclosure.

[0063] Figure 4A is a diagram showing the output voltage P1 of the matching circuit 212. Figure 4A As shown, the voltage P1 output from the matching circuit 212 and input to the comparison unit 214 may have voltage characteristics having different amplitudes according to frequency bands. Figure 4A , it can be seen that the voltage P1 includes a noise component having a small voltage.

[0064] Figure 4B 2 is a diagram showing the output voltage P2 of the comparator 214. Figure 4B As shown, small noise components are removed by the action of the threshold voltage Vth.

[0065] Figure 4C 2 is a diagram showing the output voltage P3 of the rectifier 216. Figure 4C As shown, by performing rectification after removing the noise component, a good rectified voltage can be obtained.

[0066] Figure 5 is a view illustrating determination of a battery cell charging order of an environmentally friendly vehicle according to one form of the present disclosure.

[0067] like Figure 5 As shown, by applying the current value and voltage value obtained when each of the multiple battery cells is discharged, the health state (SOH) of each of the multiple battery cells 262 is predicted from the impedance change according to the temperature and current density of each of the multiple battery cells 262.

[0068] Therefore, the SOH for each of the plurality of battery cells 262 can be predicted, and by using the predicted SOH, the first reference voltage Vth of the comparator 214 is variably applied to each of the plurality of battery cells 262. The reason for variably applying the first reference voltage Vth of the comparator 214 is that it is difficult to fully charge the battery cell 262 with a short health state to the second reference voltage, and it may take a long time to charge. In order to solve this problem, the first reference voltage Vth is variably applied by predicting the SOH value of each of the plurality of battery cells 262.

[0069] For example, Figure 5 As shown, if the SOH of a specific battery cell 262 is 80% to 100%, when the corresponding battery cell 262 is charged, the first reference voltage Vth of the comparator 214 is 1.0*Vth applied as is. If the SOH of a specific battery cell 262 is 60% to 80%, when the battery cell is charged, the first reference voltage Vth of the comparator 214 applies only 80% of 0.8*Vth. If the SOH of a specific battery cell 262 is 40% to 60%, when the battery cell is charged, the first reference voltage Vth of the comparator 214 applies only 60% of 0.6*Vth. If the SOH of a specific battery cell 262 is 20% to 40%, when the battery cell is charged, the first reference voltage Vth of the comparator 214 applies only 40% of 0.4*Vth.

[0070] In this case, if Figure 5As shown, the charging priority of each battery cell among the plurality of battery cells 262 gives higher priority to a battery cell 262 having a small SOH or a battery cell having a large ratio (%) of the first reference voltage Vth actually applied to the comparator 214 .

[0071] Fig. 6A and Figure 6B is a flow chart illustrating a battery charging method for an environmentally friendly vehicle according to one form of the present disclosure.

[0072] It is identified whether wireless charging is activated while the engine of the environmentally-friendly vehicle 100 is turned off ( 604 ). Here, activation of wireless charging includes activation of the external wireless charging device 120 and the wireless charging receiver 142 as well as the battery 140 of the environmentally-friendly vehicle 100 .

[0073] If wireless charging is activated while the engine of the environmentally friendly vehicle 100 is turned off, the charging controller 202 receives wireless power through the wireless power receiver 142 (606). If the received power is greater than the first reference voltage Vref (yes in 608), the charging controller 202 rectifies the received power and then performs DC-DC conversion (610). Next, the charging controller 202 identifies the current charging voltage of each of the plurality of battery cells 262 (612).

[0074] In this case, when the environmentally-friendly vehicle 100 is in the shutdown state and it is difficult to directly measure the charging voltage of each of the plurality of battery cells 262, the charging controller 202 can identify the charging voltage of each of the plurality of battery cells 262 from the state information of each of the plurality of battery cells 262 stored in the memory 204. That is, the environmentally-friendly vehicle 100 can determine the charging order by checking the charging state of each of the plurality of battery cells 262 by referring to the state information stored in the memory 204 even in the startup shutdown state.

[0075] If the charging voltage of each of the plurality of battery cells 262 is less than the second reference voltage (yes in 614), the charging controller 202 calculates the voltage difference between the plurality of battery cells 262 and determines the charging priority of each of the plurality of battery cells 262 based on the calculated voltage difference (616). If the charging voltage of each of the plurality of battery cells 262 is greater than or equal to the second reference voltage (no in 614), the charging controller 202 proceeds to step 626 to deactivate the battery balancing unit 252 and the wireless power receiver 142.

[0076] When the charging priority of each battery cell in the plurality of battery cells 262 is determined, the charging controller 202 sequentially activates the plurality of battery balancing units 252 to match the priority (618). By activating the corresponding battery balancing unit 252, each battery cell in the plurality of battery cells 262 can be charged.

[0077] The charging controller 202 performs balancing (charging) of each of the plurality of battery cells 262 based on the charging priority determined above (620). Here, charging of each of the plurality of battery cells 262 is referred to as "balancing" because the charging and discharging of the plurality of battery cells 206 are managed so that, if possible, all of the plurality of battery cells 262 are charged / discharged uniformly without biasing any one battery cell.

[0078] If the voltage of each of the plurality of battery cells 262 reaches the desired second reference voltage (Yes in 622 ), the charging controller 202 stores the voltage information of the battery cell 262 in which charging is completed in the memory 204 ( 624 ).

[0079] Through this process, when balancing (charging) of each of the plurality of battery cells 262 is completed in a high priority order, the charging controller 202 deactivates the plurality of battery balancing units 252 and the wireless power receiver 142 to complete charging of the battery 140 (626).

[0080] The disclosed forms are merely illustrative of the technical ideas, and those skilled in the art will appreciate that various modifications, changes, and substitutions may be made without departing from the present disclosure. Therefore, the exemplary forms and drawings disclosed above are not intended to limit the technical ideas, but rather to describe the technical spirit, and the scope of the technical ideas is not limited by the forms and drawings.

Claims

1. An environmentally friendly vehicle, comprising: a wireless power receiver configured to wirelessly receive power from an external charging device; a memory configured to store status information of each battery cell of the plurality of battery cells; a plurality of battery balancing units, respectively provided to corresponding battery cells among the plurality of battery cells, and A controller configured to control a charging sequence of battery cells among the plurality of battery cells using the status information stored in the memory when the engine of the environmentally friendly vehicle is in an off state, and to sequentially wake up battery balancing units among the plurality of battery cells based on the charging sequence of the battery cells among the plurality of battery cells, and to control each battery cell to be charged among the plurality of battery cells based on the charging sequence, and when charging of the battery cells among the plurality of battery cells is completed, the controller is configured to store voltage information of the charged battery cells in the memory.

2. The environmentally friendly vehicle according to claim 1, wherein: The controller is configured to: setting a charging order of the battery cells of the plurality of battery cells based on a charging state of each battery cell, and Among the plurality of battery cells, a higher priority in the charging order is set to a battery cell having a lower state of charge.

3. The environmentally friendly vehicle according to claim 1, wherein: The controller is configured to: receiving operation information of the wireless power receiver, and When charging of one of the plurality of battery cells is completed, another of the plurality of battery cells is charged by resetting the wireless power receiver.

4. The environmentally friendly vehicle according to claim 1, wherein: The controller is configured to: receiving operation information of the wireless power receiver, and When an abnormal operation of the wireless power receiver is detected from the operation information, the wireless power receiver is initialized to a normal state by resetting the wireless power receiver.

5. An environmentally friendly vehicle, comprising: a wireless power receiver configured to wirelessly receive power from an external charging device, and the wireless power receiver includes a comparator configured to select a frequency of the received power; a memory configured to store status information of each battery cell of the plurality of battery cells; as well as A controller configured to control the frequency selection of the comparator and control the charging sequence of the battery cells among the plurality of battery cells using the status information stored in the memory when the engine of the environmentally friendly vehicle is in an off state, and when the controller controls the charging sequence of the battery cells among the plurality of battery cells, the controller is configured to assign a higher priority to the battery cells with a lower state of charge, and the comparator is configured to select only a frequency band of voltages greater than a threshold voltage; and the controller is configured to variably apply the magnitude of the threshold voltage based on the health state of each battery cell among the plurality of battery cells.

6. The environmentally friendly vehicle according to claim 5, wherein: When charging a battery cell having 100% of the health state among the plurality of battery cells, applying a predetermined threshold voltage of 100% to the comparator; and When the state of health of a battery cell among the plurality of battery cells is less than 100%, a ratio less than 100% proportional to the state of health of the corresponding battery cell is applied to the comparator.

7. The environmentally friendly vehicle according to claim 5, further comprising: A plurality of battery balancing units are respectively arranged in corresponding battery cells among the plurality of battery cells, Wherein, the controller is configured as: sequentially waking up the battery balancing units among the plurality of battery balancing units based on the charging sequence of the battery units among the plurality of battery units, and Each battery cell to be charged among the plurality of battery cells is controlled based on the charging sequence.

8. The environmentally friendly vehicle according to claim 7, wherein: When charging of a battery cell among the plurality of battery cells is completed, the controller is configured to update information of the memory with voltage information of the charged battery cell.

9. The environmentally friendly vehicle according to claim 5, wherein: The controller is configured to: receiving operation information of the wireless power receiver, and When charging of one of the plurality of battery cells is completed, another of the plurality of battery cells is charged by resetting the wireless power receiver.

10. The environmentally friendly vehicle according to claim 5, wherein: The controller is configured to: receiving operation information of the wireless power receiver, and When an abnormal operation of the wireless power receiver is detected from the operation information, the wireless power receiver is initialized to a normal state by resetting the wireless power receiver.

11. A charging control method for an environmentally friendly vehicle, wherein: The environmentally friendly vehicle comprises: a wireless power receiver for wirelessly receiving power from an external charging device, and the wireless power receiver comprises a comparator for selecting a frequency of the received power; a memory for storing state information of each battery cell of a plurality of battery cells; and a controller for controlling a charging sequence of the battery cells of the plurality of battery cells, the method comprising the following steps: The controller controls the frequency selection of the comparator; and When the engine of the environmentally friendly vehicle is in an off state, the controller controls the charging order of each of the multiple battery cells using the status information stored in the memory, and when controlling the charging order of the battery cells in the multiple battery cells, a higher charging priority is assigned to a battery cell with a lower charging state, and only a frequency band of a voltage greater than a threshold voltage is selected by the comparator; and the magnitude of the threshold voltage is variably applied by the controller based on the health state of each of the multiple battery cells.

12. The method according to claim 11, wherein: When charging a battery cell having 100% of the health state among the plurality of battery cells, applying a predetermined threshold voltage of 100% to the comparator; and When the state of health of a battery cell among the plurality of battery cells is less than 100%, a ratio less than 100% proportional to the state of health of the battery cell is applied to the comparator.

13. The method according to claim 11, further comprising: When the battery cell is fully charged, the controller updates the state information of the memory with voltage information of the battery cell among the plurality of battery cells.

14. The method according to claim 11, comprising: receiving, by the controller, operation information of the wireless power receiver; and When charging of one of the plurality of battery cells is completed, another of the plurality of battery cells is charged by the controller by resetting the wireless power receiver.

15. The method according to claim 11, comprising: receiving, by the controller, operation information of the wireless power receiver; and When an abnormal operation of the wireless power receiver is detected from the operation information, the wireless power receiver is initialized to a normal state by resetting the wireless power receiver by the controller.

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