Method and device for adjusting charging current of charging pile according to supply voltage and charging pile

Abstract

The application discloses a method and device for adjusting charging current of a charging pile according to supply voltage and a charging pile, wherein the system voltage, i.e., the supply voltage, of an alternating current power grid connected with an alternating current charging pile of an electric vehicle is detected in real time; when the system voltage is in a normal supply voltage range, the charging pile of the electric vehicle controls the charging current according to real-time charging demand of the vehicle under the condition that the maximum output power of the charging pile is not exceeded; when the system voltage is lower than the normal supply voltage range, the alternating current charging pile of the electric vehicle interacts with the vehicle-mounted charger through communication to reduce the alternating current charging current of the electric vehicle until the system voltage returns to normal, so that the system voltage is stabilized and the serious low voltage of a rural power grid caused by unordered charging of a large number of electric vehicles is reduced.

Description

Technical Field

[0001] This invention relates to the field of charging pile charging current adjustment technology, and more specifically to a method, device and charging pile for adjusting the charging current of a charging pile based on the power supply voltage. Background Technology

[0002] Currently, in my country's county and township markets, the market penetration rate of pure electric vehicles is 17%, with gasoline-powered vehicles still dominating the market. Therefore, the development potential of my country's county and township markets remains enormous for new energy vehicle companies. However, in rural areas with dispersed residential distribution substations, the dispersed nature of users results in longer power supply lines (cables) and larger voltage drops during power supply. This leads to lower voltage at the end of the rural power grid when charging stations are connected, and the voltage fluctuations are significant with load changes, easily triggering the undervoltage protection of the charging stations, thus preventing electric vehicles from charging. Considering the future transformation of rural power grids, the promotion of new energy vehicles in rural areas needs to ensure that charging for these vehicles can meet the charging needs under current grid conditions.

[0003] Currently available charging stations cannot guarantee stable and efficient charging even under fluctuating power supply voltage. Therefore, a charging station system capable of automatically adjusting the charging current is needed to ensure safety and efficiency under varying power supply conditions. Summary of the Invention

[0004] This invention provides a method, device, and charging pile for adjusting the charging current of a charging pile based on the power supply voltage. It solves the problem of voltage fluctuations in rural power grids caused by electric vehicle charging, and ensures that the charging pile can work normally and charge at maximum efficiency when the power grid experiences low voltage.

[0005] According to one aspect of the present invention, in order to solve the above-mentioned technical problems, the present invention provides a method for adjusting the charging current of a charging pile according to the power supply voltage, comprising the following steps:

[0006] S1. Detect the current power supply voltage of the charging pile;

[0007] S2. Based on the detected power supply voltage at the current moment, determine the charging current level of the charging pile at subsequent moments; wherein, the power supply voltage at the current moment and the charging current in the charging current level at the subsequent moments are positively correlated.

[0008] S3. Adjust the charging current of the charging pile at the determined charging current level for the subsequent time according to the determination, and return to step S1 after a certain interval.

[0009] Preferably, in the method for adjusting the charging current of a charging pile according to the power supply voltage of the present invention, step S2 specifically includes:

[0010] S21. Set the charging current of the charging pile to the maximum value within the current charging current range;

[0011] S22. After setting the charging current, check the power supply voltage of the charging pile;

[0012] S23. Determine whether the power supply voltage mentioned in step S22 is greater than or equal to the preset charging voltage threshold. If yes, proceed to step S24; otherwise, proceed to step S25.

[0013] S24. Determine whether the current charging current is in the charging current reduction stage. If yes, set the current charging current level as the charging current level for the charging pile in the future. If no, further determine whether the current charging current level is the highest level. If it is the highest level, use the highest level as the charging current level for the charging pile in the future. If it is not the highest level, set a level higher than the current charging current level as the charging current level for the charging pile in the future.

[0014] S25. Determine whether the current charging current is in the charging current adjustment stage. If yes, set a lower charging current level than the current charging current level as the charging current level for the charging pile in the future. If no, further determine whether the current charging current level is the lowest level. If it is the lowest level, use the lowest level as the charging current level for the charging pile in the future. If it is not the lowest level, set a lower charging current level than the current charging current level as the charging current level for the charging pile in the future.

[0015] The charging current reduction phase refers to the situation where, during the previous execution of step S25, the current charging current level is not the lowest level, and a lower level than the current charging current level is set as the charging current level for subsequent moments of the charging pile; the charging current increase phase refers to the situation where, during the previous execution of step S24, the current charging current level is not the highest level, and a higher level than the current charging current level is set as the charging current level for subsequent moments of the charging pile.

[0016] Preferably, in the method for adjusting the charging current of a charging pile according to the power supply voltage of the present invention, the power supply voltage is detected at a preset frequency.

[0017] Preferably, in the method for adjusting the charging current of a charging pile according to the power supply voltage of the present invention, the time length of the interval between certain times in step S3 is equal to the interval between the detection of power supply voltages on adjacent sides.

[0018] Preferably, in the method of adjusting the charging current of a charging pile according to the power supply voltage of the present invention, in setting a lower charging current level than the current charging current level as the charging current level of the charging pile at a later time, one or more charging current levels are adjusted down or up each time.

[0019] Preferably, in the method of adjusting the charging current of the charging pile according to the power supply voltage of the present invention, the charging pile interacts with the on-board charger of the electric vehicle to be charged through communication, so as to determine the charging current level of the charging pile at subsequent times under the premise of satisfying the charging strategy specified by the electric vehicle to be charged.

[0020] According to another aspect of the present invention, in order to solve its technical problem, the present invention also provides a device for adjusting the charging current of a charging pile according to the supply voltage, comprising the following units:

[0021] The power supply voltage detection unit is used to detect the current power supply voltage of the charging pile.

[0022] The processing unit is used to determine the charging current level of the charging pile at subsequent times based on the detected current power supply voltage; wherein the current power supply voltage and the charging current in the charging current level at subsequent times are positively correlated.

[0023] The charging current adjustment unit is used to adjust the charging current of the charging pile at the determined charging current level at the subsequent time, and return to the power supply voltage detection unit after a certain interval.

[0024] According to another aspect of the present invention, in order to solve its technical problem, the present invention also provides a charging pile, including the above-described device for adjusting the charging current of the charging pile according to the power supply voltage.

[0025] The method, apparatus, and charging pile for adjusting the charging current of a charging pile based on the supply voltage of the present invention have the following technical effects: The present invention detects the system voltage of the AC power grid to which the electric vehicle AC charging pile is connected in real time, i.e., the supply voltage; when the system voltage is within the normal supply voltage range, the electric vehicle charging pile, without exceeding its own maximum output power limit, has its charging current controlled by the on-board charger according to the real-time charging needs of the vehicle; when the system voltage is lower than the normal supply voltage range, the electric vehicle AC charging pile interacts with the on-board charger through communication to reduce the AC charging current of the electric vehicle until the system voltage returns to normal, so as to maintain system voltage stability and reduce the serious low voltage caused to the rural power grid by disorderly charging after a large number of electric vehicles are connected. Attached Figure Description

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0027] Figure 1 This is a flowchart of an embodiment of the method for adjusting the charging current of a charging pile according to the power supply voltage in the present invention;

[0028] Figure 2 This is a schematic diagram of an embodiment of the charging current gear in the present invention;

[0029] Figure 3 This is a schematic diagram of the principle of an embodiment of the device for adjusting the charging current of a charging pile according to the power supply voltage in the present invention. Detailed implementation manners

[0030] For a clearer understanding of the technical features, objectives, and effects of the present invention, the specific implementation manners of the present invention will now be described in detail with reference to the accompanying drawings.

[0031] Reference Figure 1 , the method for adjusting the charging current of a charging pile according to the power supply voltage in this embodiment includes the following steps:

[0032] S0. Preset a charging voltage threshold Vset and set the current charging current to the maximum current gear iMax. As Figure 2 shown, the charging current of the first gear is Imin, the charging current of the second gear is a*Imax, the charging current of the third gear is b*Imax, the charging current of the fourth gear is c*Imax, the charging current of the fifth gear is d*Imax, the charging current of the sixth gear is Imax, where a < b < c < d < 1; where Imax is the maximum charging current supported by the charging pile. Imin can be the minimum charging current that can be represented by PWM stipulated by the national standard or the minimum charging current set by oneself; the embodiment of the present invention does not limit this. The middle four charging current gears can be set according to the maximum charging current (in this example), or can be set according to the minimum charging current, or can be set by oneself, and the present invention does not limit this. The charging current gear is a charging current range or a determined charging current value. In this embodiment, a determined charging current value is used for illustration. Exemplarily, taking the 220V power supply mains grid as an example, the preset charging voltage threshold Vset = 205V or Vset = 195V. The embodiment of the present invention does not limit this, and in other cases, it can be set by oneself, and the present invention is not limited thereto.

[0033] At the same time, in other embodiments of the present invention, other gears can also be set as the current charging current, and the present invention is not limited thereto.

[0034] S1. Detect the power supply voltage at the current moment of the charging pile. The power supply voltage is detected according to a preset frequency, and this power supply voltage is the system voltage of the AC power grid connected to the electric vehicle AC charging pile. The frequency can be, for example, 1 / 10s, 1 / 1min, 1 / 10min.

[0035] S2. Based on the detected power supply voltage at the current moment, determine the charging current level of the charging pile at subsequent moments; wherein, the power supply voltage at the current moment and the charging current in the charging current level at the subsequent moments are positively correlated.

[0036] Step S2 specifically includes:

[0037] S21. Set the charging current of the charging pile to the maximum value within the current charging current range;

[0038] S22. After setting the charging current, check the power supply voltage of the charging pile;

[0039] S23. Determine whether the power supply voltage mentioned in step S22 is greater than or equal to the preset charging voltage threshold. If yes, proceed to step S24; otherwise, proceed to step S25.

[0040] S24. Determine whether the current charging current is in the charging current reduction stage. If yes, set the current charging current level as the charging current level for the charging pile in the future. If no, further determine whether the current charging current level is the highest level. If it is the highest level, use the highest level as the charging current level for the charging pile in the future. If it is not the highest level, set a higher level than the current charging current level as the charging current level for the charging pile in the future. For example, it can be adjusted from the third level b*Imax to the fourth level c*Imax. This embodiment of the invention does not limit this.

[0041] S25. Determine whether the current charging current is being increased. If so, set a lower charging current level than the current charging current level as the charging current level for the charging pile in the future. If not, further determine whether the current charging current level is the lowest level. If it is the lowest level, use the lowest level as the charging current level for the charging pile in the future. If it is not the lowest level, set a lower charging current level than the current charging current level as the charging current level for the charging pile in the future. For example, it can be adjusted from the third or fourth level c*Imax to the third level b*Imax. This embodiment of the invention does not limit this.

[0042] The charging current reduction phase refers to the situation where, during the previous execution of step S25, the current charging current level is not the lowest level, and a lower level than the current charging current level is set as the charging current level for subsequent moments of the charging pile; the charging current increase phase refers to the situation where, during the previous execution of step S24, the current charging current level is not the highest level, and a higher level than the current charging current level is set as the charging current level for subsequent moments of the charging pile.

[0043] S3. Adjust the charging current of the charging pile at the determined charging current level for the subsequent time according to the determination, and return to step S1 after a certain time interval. In this embodiment, the time interval is equal to the interval between the detection of the power supply voltage on both sides. However, the present invention is not limited to this. In other embodiments, the interval can be two intervals between the detection of the power supply voltage on both sides, or other time intervals.

[0044] In this embodiment, the charging pile interacts with the on-board charger of the electric vehicle to be charged via communication to determine the charging current level of the charging pile at subsequent times, provided that the charging strategy specified by the electric vehicle to be charged is met.

[0045] refer to Figure 3 To address its technical problem, the present invention also provides a device for adjusting the charging current of a charging pile according to the power supply voltage, comprising the following units:

[0046] The power supply voltage detection unit 101 is used to detect the power supply voltage of the charging pile at the current moment;

[0047] The processing unit 102 is used to determine the charging current level of the charging pile at a subsequent moment based on the detected power supply voltage at the current moment; wherein the power supply voltage at the current moment and the charging current in the charging current level at the subsequent moment are positively correlated.

[0048] The charging current adjustment unit 103 is used to adjust the charging current of the charging pile at the time of the determined charging current level, and return to the power supply voltage detection unit after a certain interval.

[0049] The device for adjusting the charging current of the charging pile based on the supply voltage is similar in principle to the method for adjusting the charging current of the charging pile based on the supply voltage described above. For specific details, please refer to the embodiments of the above method.

[0050] The present invention also provides a charging pile, including the above-described device for adjusting the charging current of the charging pile according to the power supply voltage.

[0051] This invention detects the system voltage (i.e., the supply voltage) of the AC power grid to which the electric vehicle AC charging pile is connected in real time. When the system voltage is within the normal supply voltage range, the charging pile, without exceeding its maximum output power limit, controls the charging current according to the real-time charging needs of the vehicle through the on-board charger. When the system voltage is lower than the normal supply voltage range, the electric vehicle AC charging pile interacts with the on-board charger via communication to reduce the AC charging current of the electric vehicle until the system voltage returns to normal, thereby maintaining system voltage stability and reducing the serious low voltage caused to the rural power grid by disorderly charging after a large number of electric vehicles are connected.

[0052] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A method for adjusting the charging current of a charging pile based on the supply voltage, characterized in that, It includes the following steps: S1. Detect the current power supply voltage of the charging pile; S2. Based on the detected power supply voltage at the current moment, determine the charging current level of the charging pile at subsequent moments; wherein, the power supply voltage at the current moment and the charging current in the charging current level at the subsequent moments are positively correlated. S3. Adjust the charging current of the charging pile at the determined charging current level for the subsequent time according to the determination, and return to step S1 after a certain interval. Step S2 specifically includes: S21. Set the charging current of the charging pile to the maximum value within the current charging current range; S22. After setting the charging current, check the power supply voltage of the charging pile; S23. Determine whether the power supply voltage mentioned in step S22 is greater than or equal to the preset charging voltage threshold. If yes, proceed to step S24; otherwise, proceed to step S25. S24. Determine whether the current charging current is in the charging current reduction stage. If yes, set the current charging current level as the charging current level for the charging pile in the future. If no, further determine whether the current charging current level is the highest level. If it is the highest level, use the highest level as the charging current level for the charging pile in the future. If it is not the highest level, set a level higher than the current charging current level as the charging current level for the charging pile in the future. S25. Determine whether the current charging current is in the charging current adjustment stage. If yes, set a lower charging current level than the current charging current level as the charging current level for the charging pile in the future. If no, further determine whether the current charging current level is the lowest level. If it is the lowest level, use the lowest level as the charging current level for the charging pile in the future. If it is not the lowest level, set a lower charging current level than the current charging current level as the charging current level for the charging pile in the future. The charging current reduction phase refers to the situation where, during the previous execution of step S25, the current charging current level is not the lowest level, and a lower level than the current charging current level is set as the charging current level for subsequent moments of the charging pile; the charging current increase phase refers to the situation where, during the previous execution of step S24, the current charging current level is not the highest level, and a higher level than the current charging current level is set as the charging current level for subsequent moments of the charging pile.

2. The method for adjusting the charging current of a charging pile according to the power supply voltage as described in claim 1, characterized in that, The power supply voltage is detected according to a preset frequency.

3. The method for adjusting the charging current of a charging pile according to the power supply voltage as described in claim 1, characterized in that, The time interval mentioned in step S3 is equal to the time interval between the detection of the power supply voltage on both adjacent sides.

4. The method for adjusting the charging current of a charging pile according to the power supply voltage as described in claim 1, characterized in that, The setting of a lower charging current level than the current level is the charging current level for subsequent charging times, and the setting of a higher charging current level than the current level is the charging current level for subsequent charging times. Each time, one or more charging current levels are adjusted down or up.

5. The method for adjusting the charging current of a charging pile according to the power supply voltage as described in claim 1, characterized in that, The charging pile interacts with the on-board charger of the electric vehicle to be charged via communication to determine the charging current level of the charging pile at subsequent times, while meeting the charging strategy specified by the electric vehicle to be charged.

6. A device for adjusting the charging current of a charging pile according to the supply voltage, characterized in that, Includes the following units: The power supply voltage detection unit is used to detect the current power supply voltage of the charging pile. The processing unit is used to determine the charging current level of the charging pile at subsequent times based on the detected current power supply voltage; wherein the current power supply voltage and the charging current in the charging current level at subsequent times are positively correlated. The charging current adjustment unit is used to adjust the charging current of the charging pile at the determined charging current level at the subsequent time according to the determination of the charging current level at the subsequent time, and return to the power supply voltage detection unit after a certain interval. The processing unit is implemented based on the following steps: S21. Set the charging current of the charging pile to the maximum value within the current charging current range; S22. After setting the charging current, check the power supply voltage of the charging pile; S23. Determine whether the power supply voltage mentioned in step S22 is greater than or equal to the preset charging voltage threshold. If yes, proceed to step S24; otherwise, proceed to step S25. S24. Determine whether the current charging current is in the charging current reduction stage. If yes, set the current charging current level as the charging current level for the charging pile in the future. If no, further determine whether the current charging current level is the highest level. If it is the highest level, use the highest level as the charging current level for the charging pile in the future. If it is not the highest level, set a level higher than the current charging current level as the charging current level for the charging pile in the future. S25. Determine whether the current charging current is in the charging current adjustment stage. If yes, set a lower charging current level than the current charging current level as the charging current level for the charging pile in the future. If no, further determine whether the current charging current level is the lowest level. If it is the lowest level, use the lowest level as the charging current level for the charging pile in the future. If it is not the lowest level, set a lower charging current level than the current charging current level as the charging current level for the charging pile in the future. The charging current reduction phase refers to the situation where, during the previous execution of step S25, the current charging current level is not the lowest level, and a lower level than the current charging current level is set as the charging current level for subsequent moments of the charging pile; the charging current increase phase refers to the situation where, during the previous execution of step S24, the current charging current level is not the highest level, and a higher level than the current charging current level is set as the charging current level for subsequent moments of the charging pile.

7. A charging pile, characterized in that, Includes the device for adjusting the charging current of the charging pile according to the power supply voltage as described in claim 6.

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