A charging control method for electric vehicles in multiple application scenarios

Abstract

The present invention relates to the field of charging control technology, and proposes a method for controlling electric vehicle charging in multiple application scenarios, including: collecting the temperature and current of different electric vehicle charging piles at the current collection time and at different historical times before, marking the target electric vehicle charging pile, and obtaining the current stage sequence according to the current change trend of the target electric vehicle charging pile over time; determining the temperature fluctuation degree and initial impact weight at the collection time; determining the current adjustment trend at the collection time; according to the initial impact weight and current adjustment trend of the target electric vehicle charging pile at the historical time in the local time period, and the time interval between the historical time and the current collection time, realizing the current control of the electric vehicle charging. The present invention aims to solve the problem that the current data prediction value is inaccurate due to the change of the number of electric vehicle charging, and the rationality of the electric vehicle charging current control is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of charging control, and in particular to a charging control method for an electric vehicle in multiple application scenarios. Background Art

[0002] Affected by people's travel habits and electricity demand, electric vehicle charging piles will show the characteristics of centralized charging during specific time periods such as after get off work on weekdays. The centralized charging of electric vehicles will cause a large number of loads to be connected to the power grid of the electric vehicle charging piles, increase the total load, and affect the stability of the charging current of the charging piles. Therefore, it is necessary to adjust the charging current of the charging piles in time to avoid excessive temperature caused by unstable current or excessive load, which will damage the battery and increase safety risks.

[0003] Generally, the historical current data of charging piles is collected, and the future current data is predicted through time series prediction algorithms such as the autoregressive integral moving average model ARIMA. The current prediction value is used to control the charging current of electric vehicles and ensure the stability of the current. However, centralized charging of electric vehicles will increase the load and increase the temperature of wires in the power grid, resulting in differences in the actual influence weights of different historical current data on the current data prediction value. The existing influence weights cannot be set according to the number of electric vehicles charged, which will lead to inaccurate prediction values ​​of current data and reduce the rationality of electric vehicle charging current control. Summary of the invention

[0004] The present invention provides an electric vehicle charging control method under multiple application scenarios to solve the problem that the change in the number of electric vehicle charges leads to inaccurate prediction of current data and reduces the rationality of electric vehicle charging current control. The technical solutions adopted are as follows:

[0005] An embodiment of the present invention provides a method for controlling charging of an electric vehicle in multiple application scenarios, the method comprising the following steps:

[0006] At each collection moment, the temperature and current of the electric vehicle charging pile are collected respectively, and any electric vehicle charging pile in the electric vehicle charging area is recorded as a target electric vehicle charging pile. According to the change trend of the current of the target electric vehicle charging pile over time, the current of the target electric vehicle charging pile is grouped into different current stage sequences; the collection moment includes the current collection moment and a preset number of historical moments before;

[0007] According to the difference between the current value contained in the current stage sequence and the current change trend, determine the current trend error at the collection time corresponding to the current contained in the current stage sequence, determine the first extreme value moment and the second extreme value moment of the collection time according to the temperature change trend at different collection times before and after the collection time, determine the temperature fluctuation at any collection time according to the current trend error, the first extreme value moment and the second extreme value moment of the target electric vehicle charging pile at any collection time, and obtain the initial influence weight of the target electric vehicle charging pile at any collection time according to the total number of electric vehicle charging piles, the current of all electric vehicle charging piles at all collection times and the temperature fluctuation of the target electric vehicle charging pile at any collection time;

[0008] According to the overall change trend of the current of all electric vehicle charging piles at different collection times in the local time period and the instantaneous change trend at the collection time, the current adjustment trend at the collection time is determined;

[0009] According to the initial impact weight of the target electric vehicle charging pile at the historical moment in the local time period, the current adjustment trend, and the time interval between the historical moment and the current collection moment, the current control of the electric vehicle charging is realized.

[0010] Furthermore, the current of the target electric vehicle charging pile is formed into a sequence of different current stages, including the specific method of:

[0011] Performing curve fitting on the order of the currents contained in the current sequence of the target electric vehicle charging pile and the current to obtain a current fitting curve;

[0012] The value greater than 0.2 is recorded as the first case, the value less than -0.2 is recorded as the second case, and the value greater than or equal to -0.2 and less than or equal to 0.2 is recorded as the third case;

[0013] The slope of the current fitting value corresponding to each order in the current sequence is obtained according to the current fitting curve, and all the slopes are arranged in order from small to large. When the continuous slopes are the same case in the first case, the second case or the third case, these continuous slopes are divided into the same current stage sequence; when the continuous slopes appear in any case except the case that they are all the same case in the first case, the second case and the third case, the slopes that appear in any case except the case that they are all the same case in the first case, the second case and the third case are divided into the next current stage sequence, until all the currents in the current sequence are divided into the current stage sequence.

[0014] Furthermore, the current trend error at the acquisition moment is determined by:

[0015] Performing curve fitting on the order of the currents contained in the current phase sequence and the currents to obtain a current phase fitting curve;

[0016] For any acquisition moment, the absolute value of the difference between the current corresponding to the acquisition moment and the current fitting value corresponding to the current stage fitting curve at the acquisition moment is recorded as the current trend error at the acquisition moment.

[0017] Furthermore, the first extreme value moment and the second extreme value moment of the acquisition moment are determined by:

[0018] Arrange all the temperatures of the target electric vehicle charging pile at and before the current collection time in the order of the collection time to obtain the temperature sequence of the target electric vehicle charging pile, perform curve fitting on the order of the temperatures contained in the temperature sequence of the target electric vehicle charging pile and the temperatures, obtain the temperature fitting curve, and obtain the collection time corresponding to all extreme value points of the temperature fitting curve;

[0019] For each collection moment, the collection moment corresponding to the latest extreme value point earlier than the collection moment is recorded as the first extreme value moment of the collection moment, and the collection moment corresponding to the earliest extreme value point later than the collection moment is recorded as the second extreme value moment of the collection moment.

[0020] Furthermore, the temperature fluctuation at the time of acquisition includes the following specific methods:

[0021] The absolute value of the difference between the temperature fitting values ​​corresponding to the second extreme value moment and the first extreme value moment of the target electric vehicle charging pile at the same collection time is recorded as the first difference at the same collection time; the difference between the second extreme value moment and the first extreme value moment of the target electric vehicle charging pile at the same collection time is recorded as the second difference at the same collection time; the ratio of the first difference to the second difference at the same collection time is recorded as the first ratio at the same collection time;

[0022] The product of the first ratio at the same acquisition time and the current trend error of the target electric vehicle charging pile at the same acquisition time is recorded as the temperature fluctuation of the target electric vehicle charging pile at the same acquisition time.

[0023] Further, the initial influence weight of the target electric vehicle charging pile at any collection time is obtained according to the total number of electric vehicle charging piles, the current of all electric vehicle charging piles at all collection times, and the temperature fluctuation of the target electric vehicle charging pile at any collection time, including the specific method of:

[0024] The cumulative sum of the currents of all the electric vehicle charging piles at the same collection time is recorded as the cumulative current of the electric vehicle charging piles at the same collection time;

[0025] The number of electric vehicle charging piles whose current of the charging interface is not 0 at the same collection time is recorded as the number of electric vehicle charging piles charging at the same collection time, and the ratio of the number of electric vehicle charging piles charging at any collection time to the total number of electric vehicle charging piles in the electric vehicle charging area is recorded as the second ratio at any collection time;

[0026] The maximum value of the accumulated current of the electric vehicle charging pile at any one collection time and the accumulated current of the electric vehicle charging pile at all collection times is recorded as the third ratio at any one collection time;

[0027] The product of the second ratio, the third ratio and the temperature fluctuation of the target electric vehicle charging pile at any collection time is recorded as the initial influence weight of any collection time.

[0028] Further, the current adjustment trend at the collection time is determined according to the overall change trend of the current of all electric vehicle charging piles at different collection times in the local time period and the instantaneous change trend at the collection time, including the specific method of:

[0029] The accumulated currents of the electric vehicle charging piles are arranged in the order of the collection time to obtain an accumulated current sequence, and the order of the accumulated currents in the accumulated current sequence is subjected to curve fitting with the accumulated currents contained in the accumulated current sequence to obtain an accumulated current fitting curve; according to the accumulated current fitting curve;

[0030] The absolute value of the slope of the straight line determined by two adjacent extreme value points on the cumulative current fitting curve is recorded as the overall current trend of all acquisition moments within the time period determined by the two adjacent extreme value points;

[0031] The slope of the point corresponding to the accumulated current in the accumulated current sequence on the accumulated current fitting curve is recorded as the current trend at the time of the accumulated current collection;

[0032] According to the accumulated current, overall current trend and momentary current trend of the electric vehicle charging pile at the time of collection, the current adjustment trend at the time of collection is determined.

[0033] Further, the current adjustment trend at the collection time is determined according to the accumulated current, the overall current trend and the current trend at the moment of the electric vehicle charging pile at the collection time, and the specific method includes:

[0034] The product of the linear normalized value of the current trend of the electric vehicle charging pile at the collection time, the accumulated current of the electric vehicle charging pile and the overall current trend is recorded as the current adjustment trend at the collection time.

[0035] Furthermore, the current control of the electric vehicle charging is realized according to the initial impact weight of the target electric vehicle charging pile at the historical moment in the local time period, the current adjustment trend, and the time interval between the historical moment and the current collection moment, including the specific method of:

[0036] The product of the initial impact weight of the target electric vehicle charging pile at the historical moment in the local time period and the current adjustment trend is recorded as the first product of the target electric vehicle charging pile at the historical moment, and the linear normalized value of the ratio of the time interval between the historical moment and the current collection moment and the first product of the target electric vehicle charging pile at the historical moment is recorded as the comprehensive impact weight of the target electric vehicle charging pile at the historical moment;

[0037] According to the comprehensive influence weight of each electric vehicle charging pile in the electric vehicle charging area at each historical moment in a local time period, the current control of electric vehicle charging is realized.

[0038] Furthermore, the current control of electric vehicle charging is realized according to the comprehensive influence weight of each electric vehicle charging pile in the electric vehicle charging area at each historical moment in a local time period, and the specific method includes:

[0039] The predicted value is input into the PID controller to obtain the current control instruction at the next collection moment of the current at the current collection moment, and the current at the next collection moment of the current at the current collection moment is controlled according to the current control instruction.

[0040] The beneficial effects of the present invention are:

[0041] The present application first divides the current stage sequence according to the differences in the trend characteristics of the current corresponding to the pre-charging stage, the constant current charging stage and the constant voltage charging stage experienced by the electric vehicle charging pile in the process of charging the vehicle, analyzes the current change trend in the same charging stage, and improves the accuracy of current prediction and control; then, according to the difference between the current value and the current change trend, determines the current trend error, the first extreme moment and the second extreme moment at each acquisition moment, the first extreme moment and the second extreme moment are the positions where the current trend changes before and after the acquisition moment and are closest to the acquisition moment, obtains the temperature fluctuation at the acquisition moment, that is, the severity of the change in current and temperature before and after the acquisition moment, and then obtains the target electric vehicle charging pile at The initial impact weight at any collection moment is the initial value of the impact weight that should be given to the current collected at the target electric vehicle charging pile at the collection moment; further, considering that the larger the current in the power grid, the greater the necessity to adjust the power grid current of the electric vehicle charging pile, the current change trend is further analyzed to determine the current adjustment trend at the collection moment, and according to the initial impact weight of the target electric vehicle charging pile at the historical moment in the local time period, the current adjustment trend, and the time interval between the historical moment and the current collection moment, the current control of the electric vehicle charging is realized, so as to solve the problem that the existing change in the number of electric vehicle charging leads to inaccurate prediction of the current data and reduces the rationality of the electric vehicle charging current control. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0043] Figure 1 A schematic flow chart of a method for controlling charging of an electric vehicle in multiple application scenarios provided by an embodiment of the present invention;

[0044] Figure 2 A flow chart for obtaining temperature fluctuation provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] See also Figure 1 , which shows a flow chart of an electric vehicle charging control method in multiple application scenarios provided by an embodiment of the present invention, the method comprising the following steps:

[0047] Step S001, respectively collecting the temperature and current of the electric vehicle charging pile at each collection moment, recording any electric vehicle charging pile in the electric vehicle charging area as a target electric vehicle charging pile, and organizing the current of the target electric vehicle charging pile into different current stage sequences according to the change trend of the current of the target electric vehicle charging pile over time; the collection moment includes a preset number of historical moments before and before the current collection moment.

[0048] The total number of electric vehicle charging piles in the electric vehicle charging area is counted. At each collection moment, a temperature sensor is used to collect the temperature of the charging interface of each electric vehicle charging pile, and a current sensor is used to collect the current of the charging interface of each electric vehicle charging pile.

[0049] When the current of the charging interface of the electric vehicle charging pile is 0, it is determined that the electric vehicle charging pile is not charging. When the current of the charging interface of the electric vehicle charging pile is not 0, it is determined that the electric vehicle charging pile is charging. Therefore, the number of electric vehicle charging piles charging at the corresponding collection time can be determined based on the current values ​​of the charging interfaces of all electric vehicle charging piles collected at each collection time.

[0050] It is understandable that all collection moments before the current collection moment are historical moments.

[0051] Preferably, in one embodiment of the present application, when collecting temperature and current, the time interval between adjacent collection moments is set to 4 seconds, and the temperature and current are collected within 20 minutes in total, and the collection moments of temperature and current are the same. In actual application, as other implementation methods, the implementer can decide the sampling frequency and sampling quantity of the temperature and current according to the actual situation, and the present application does not impose any special restrictions.

[0052] Any electric vehicle charging pile in the electric vehicle charging area is recorded as a target electric vehicle charging pile, and all temperatures and currents of the target electric vehicle charging pile at and before the current collection time are arranged in the order of the collection time to obtain the temperature sequence and current sequence of the target electric vehicle charging pile.

[0053] In the process of charging the vehicle with an electric vehicle charging pile, it needs to go through the pre-charging stage, the constant current charging stage and the constant voltage charging stage. In the pre-charging stage, in order to avoid the impact of charging on the battery, the current is generally small; in the constant current charging stage, in order to achieve fast charging, the current maintains a large constant value. When the battery voltage is close to the rated voltage, the charging mode switches to the constant voltage charging stage; in the constant voltage charging stage, in order to prevent overcharging problems, the current gradually decreases. Therefore, there are differences in the current change trends in different charging stages. In the process of charging the vehicle with an electric vehicle charging pile, heat is generated, causing the collected temperature to change. In order to more accurately predict the current data and improve the rationality and accuracy of the electric vehicle charging current control, the current sequence is divided according to the current change trends in different charging stages.

[0054] Specifically, the order of the currents contained in the current sequence of the target electric vehicle charging pile in the current sequence is curve-fitted with the current to obtain the current fitting curve. The value greater than 0.2 is recorded as the first case, the value less than -0.2 is recorded as the second case, and the value greater than or equal to -0.2 and less than or equal to 0.2 is recorded as the third case. According to the current fitting curve, the slope of the current fitting value corresponding to each order in the current sequence is obtained, all slopes are arranged in order from small to large, and the continuous slopes are compared with 0.2 and -0.2 respectively. When the continuous slopes are the same in the first case, the second case or the third case, these continuous slopes are divided into the same current stage sequence; when the continuous slopes appear in any case except the same case in the first case, the second case and the third case, the slopes that appear in any case except the same case in the first case, the second case and the third case are divided into the next current stage sequence, until all the currents in the current sequence are divided into the current stage sequence.

[0055] When the continuous slopes are -0.1, -0.5, 0.02, 0.1, 0.15, these continuous slopes are all the third case, and these continuous slopes should be classified into the same current stage sequence. When the continuous slopes are -0.1, -0.5, 0.02, 0.1, 0.15, 0.22, 0.25, the continuous slopes -0.1, -0.5, 0.02, 0.1, 0.15 are all the third case, but the continuous slopes 0.22 and 0.25 are all the first case, which is different from the third case. Therefore, the continuous slopes -0.1, -0.5, 0.02, 0.1, 0.15 should be classified into the same current stage sequence, and the continuous slopes 0.22 and 0.25 should be classified into the next same current stage sequence.

[0056] It can be understood that the first The order of the currents in the current sequence is ; This embodiment uses polynomial fitting technology to perform curve fitting. In actual application, as other implementation methods, on the basis of achieving the purpose of curve fitting, the implementer can use other existing methods such as least squares method to fit the curve, and this application does not make any special restrictions.

[0057] At this point, the current phase sequence is obtained.

[0058] Step S002: determine the current trend error at the collection moment corresponding to the current contained in the current stage sequence according to the difference between the current value contained in the current stage sequence and the current change trend; determine the first extreme value moment and the second extreme value moment at the collection moment according to the temperature change trend at different collection moments before and after the collection moment; determine the temperature fluctuation at any collection moment according to the current trend error, the first extreme value moment and the second extreme value moment of the target electric vehicle charging pile at any collection moment; obtain the initial influence weight of the target electric vehicle charging pile at any collection moment according to the total number of electric vehicle charging piles, the current of all electric vehicle charging piles at all collection moments and the temperature fluctuation of the target electric vehicle charging pile at any collection moment.

[0059] The order of the currents contained in the current stage sequence in the current stage sequence is curve fitted with the current to obtain the current stage fitting curve. For any acquisition time, the absolute value of the difference between the current corresponding to the acquisition time and the current fitting value corresponding to the current stage fitting curve at the acquisition time is recorded as the current trend error at the acquisition time.

[0060] When the current trend error is larger, the difference between the current corresponding to the current trend error and the theoretical value of the current change trend over time is larger, and the credibility of the influence of the current corresponding to the current trend error on the predicted value is smaller.

[0061] The order of the temperatures in the temperature sequence of the target electric vehicle charging pile is curve-fitted to the temperature to obtain a temperature fitting curve. The acquisition time corresponding to all extreme points of the temperature fitting curve is obtained. For each acquisition time, the acquisition time corresponding to the latest extreme point earlier than the acquisition time is recorded as the first extreme time of the acquisition time, and the acquisition time corresponding to the earliest extreme point later than the acquisition time is recorded as the second extreme time of the acquisition time.

[0062] It should be noted that when the first extreme value moment of the acquisition moment cannot be obtained, the earliest acquisition moment among all the acquisition moments is recorded as the first extreme value moment of the acquisition moment; when the second extreme value moment of the acquisition moment cannot be obtained, the latest acquisition moment among all the acquisition moments is recorded as the second extreme value moment of the acquisition moment. The first extreme value moment and the second extreme value moment are the positions where the current trend changes before and after the acquisition moment and closest to the acquisition moment.

[0063] According to the current trend error, the first extreme value moment and the second extreme value moment of the target electric vehicle charging pile at any collection moment, the temperature fluctuation degree of the target electric vehicle charging pile at the any collection moment is determined.

[0064] Preferably, as an embodiment of the present application, the absolute value of the difference between the temperature fitting values ​​corresponding to the second extreme value moment and the first extreme value moment of the target electric vehicle charging pile at the same collection moment is recorded as the first difference at the same collection moment, the difference between the second extreme value moment and the first extreme value moment of the target electric vehicle charging pile at the same collection moment is recorded as the second difference at the same collection moment, the ratio of the first difference to the second difference at the same collection moment is recorded as the first ratio at the same collection moment, and the product of the first ratio at the same collection moment and the current trend error of the target electric vehicle charging pile at the same collection moment is recorded as the temperature fluctuation of the target electric vehicle charging pile at the same collection moment.

[0065] Specifically, the temperature fluctuation of the target electric vehicle charging pile at any collection time is calculated as follows:

[0066]

[0067] In the formula, Indicates the target electric vehicle charging station In the Temperature fluctuation at each acquisition moment; Indicates the target electric vehicle charging station In the Current trend error at each acquisition moment; Indicates the target electric vehicle charging station In the The temperature fitting value corresponding to the first extreme value moment of each acquisition moment; Indicates the target electric vehicle charging station In the The temperature fitting value corresponding to the second extreme moment of the acquisition moment; Indicates the target electric vehicle charging station In the The first extreme moment of the acquisition moment; Indicates the target electric vehicle charging station In the The second extreme moment of the acquisition moment.

[0068] in, Indicates the target electric vehicle charging station In the The first difference of the acquisition moments, Indicates the target electric vehicle charging station In the The second difference of the acquisition moments, Indicates the target electric vehicle charging station In the The first ratio of the acquisition moments.

[0069] When the first difference of the target electric vehicle charging pile at the same collection time is larger, the second difference is smaller, and the current trend error is larger, the current and temperature change amplitudes are more drastic before and after the same collection time, and the current and temperature are more unstable. At this time, the temperature fluctuation of the target electric vehicle charging pile at the same collection time is larger.

[0070] The same method can be used to obtain the temperature fluctuation of any electric vehicle charging pile in the electric vehicle charging area at any collection time. The temperature fluctuation acquisition flow chart is as follows: Figure 2 shown.

[0071] At this point, the temperature fluctuation of each electric vehicle charging pile at each collection moment is obtained.

[0072] When electric vehicle charging piles are charged in a centralized manner, a large number of loads are connected to the power grid of the electric vehicle charging piles, and the total load increases, which is easy to affect the stability of the charging current of the charging piles. Therefore, it is necessary to evaluate the influence weight of the current collected at each collection time on the predicted value of the current based on the temperature fluctuation, combined with the current of all electric vehicle charging piles that are charged at the same time at each collection time and the number of electric vehicle charging piles that are charged.

[0073] The cumulative sum of the currents of all the electric vehicle charging piles at the same collection time is recorded as the cumulative current of the electric vehicle charging piles at the same collection time.

[0074] According to the total number of electric vehicle charging piles, the accumulated current of all electric vehicle charging piles at all collection moments, the number of electric vehicle charging piles being charged, and the temperature fluctuation of the target electric vehicle charging pile at any collection moment, the initial influence weight of the target electric vehicle charging pile at any collection moment is obtained.

[0075] Preferably, as an embodiment of the present application, the ratio of the number of electric vehicle charging piles charging at any collection moment to the total number of electric vehicle charging piles in the electric vehicle charging area is recorded as the second ratio at any collection moment, the accumulated current of the electric vehicle charging pile at any collection moment and the maximum value of the accumulated current of the electric vehicle charging piles at all collection moments are recorded as the third ratio at any collection moment, and the product of the second ratio, the third ratio and the temperature fluctuation of the target electric vehicle charging pile at any collection moment is recorded as the initial impact weight at any collection moment.

[0076] Specifically, the calculation formula for the initial impact weight of the target electric vehicle charging pile at any collection time is:

[0077]

[0078] In the formula, Indicates the target electric vehicle charging station In the The initial impact weight of each collection moment; Indicates The number of electric vehicle charging piles that are charging at the collection time; Indicates the total number of electric vehicle charging piles in the electric vehicle charging area; Indicates The accumulated current of the electric vehicle charging pile at each collection moment; Indicates the maximum value of the accumulated current of the electric vehicle charging pile at all collection moments; Indicates the target electric vehicle charging station In the The temperature fluctuation at each sampling moment.

[0079] in, Indicates the target electric vehicle charging station In the The second ratio of the acquisition moments; Indicates The third ratio of the acquisition moments.

[0080] When the second ratio, the third ratio and the temperature fluctuation of the target electric vehicle charging pile at the collection time are greater, the cumulative amount of charging current at the collection time is greater, the load of the electric vehicle charging pile grid is greater, and the grid current of the electric vehicle charging pile needs to be adjusted to adapt to the larger load. At this time, in order to obtain a more accurate current prediction value, a greater influence weight should be given to the current collected at the target electric vehicle charging pile at the collection time.

[0081] The same method can be used to obtain the initial influence weight of any electric vehicle charging pile in the electric vehicle charging area at any collection time.

[0082] At this point, the initial impact weight of each electric vehicle charging pile at each collection moment is obtained.

[0083] Step S003: Determine the current adjustment trend at the collection time according to the overall change trend of the current of all electric vehicle charging piles at different collection times in the local time period and the instantaneous change trend at the collection time.

[0084] When electric vehicle charging piles are charged centrally, in order to ensure the stability of the electric vehicle charging piles and increase the charging speed, the electric vehicle charging piles have a larger current and consume more power. When the current in the power grid is larger, the necessity of adjusting the grid current of the electric vehicle charging piles is greater. Therefore, it is necessary to further analyze the change trend of the current.

[0085] Arrange the accumulated current of the electric vehicle charging pile in the order of the collection time to obtain the accumulated current sequence, and perform curve fitting on the order of the accumulated current in the accumulated current sequence and the accumulated current contained in the accumulated current sequence to obtain the accumulated current fitting curve. According to the accumulated current fitting curve, obtain the slope of the point corresponding to each order in the accumulated current sequence on the accumulated current fitting curve, and at the same time, obtain all the extreme points on the accumulated current fitting curve. Obtain the slope of the straight line determined by two adjacent extreme points on the accumulated current fitting curve, and record the absolute value of the slope as the overall current trend of all collection times in the time period determined by the two adjacent extreme points corresponding to the slope. Record the slope of the point corresponding to the accumulated current on the accumulated current fitting curve as the current trend at the time of the accumulated current collection.

[0086] According to the accumulated current, overall current trend and momentary current trend of the electric vehicle charging pile at the time of collection, the current adjustment trend at the time of collection is determined.

[0087] Preferably, as an embodiment of the present application, the product of the linear normalized value of the current trend of the electric vehicle charging pile at the time of collection, the accumulated current of the electric vehicle charging pile and the overall current trend is recorded as the current adjustment trend at the time of collection.

[0088] Among them, the calculation formula for the current adjustment trend at any acquisition time is:

[0089]

[0090] In the formula, Indicates Current adjustment trend at each acquisition moment; Indicates The accumulated current of the electric vehicle charging pile at each collection moment; Indicates The overall current trend of the electric vehicle charging pile at each collection moment; Indicates Current trend of electric vehicle charging pile at each collection moment; Represents a linear normalization function, which takes the linear normalization value in brackets.

[0091] When the linear normalized value of the current trend of the electric vehicle charging pile at the time of collection is larger, the current at the time of collection tends to increase more obviously. At the same time, when the accumulated current and the overall current trend of the electric vehicle charging pile at the time of collection are larger, the current at the time of collection tends to increase more obviously in the overall development trend of the current. The larger the current in the power grid, the greater the necessity to adjust the power grid current of the electric vehicle charging pile. At this time, the current adjustment trend at the time of collection is greater.

[0092] The current adjustment trend at any acquisition moment can be obtained in the same way.

[0093] At this point, the current adjustment trend at any acquisition moment is obtained.

[0094] Step S004: Implement current control of electric vehicle charging according to the initial impact weight of the target electric vehicle charging pile at the historical moment in the local time period, the current adjustment trend, and the time interval between the historical moment and the current collection moment.

[0095] According to the initial impact weight of the target electric vehicle charging pile at the historical moment in the local time period, the current adjustment trend, and the time interval between the historical moment and the current collection moment, the comprehensive impact weight of the electric vehicle charging pile at the historical moment is determined.

[0096] Preferably, as an embodiment of the present application, the product of the initial impact weight of the target electric vehicle charging pile at a historical moment in a local time period and the current adjustment trend is recorded as the first product of the target electric vehicle charging pile at the historical moment, and the linear normalized value of the ratio of the time interval between the historical moment and the current collection moment and the first product of the target electric vehicle charging pile at the historical moment is recorded as the comprehensive impact weight of the target electric vehicle charging pile at the historical moment.

[0097] Among them, the calculation formula of the comprehensive impact weight of the target electric vehicle charging pile at any collection time is:

[0098]

[0099] Indicates the target electric vehicle charging station In the The comprehensive impact weight of each collection moment; Indicates the target electric vehicle charging station In the The initial impact weight of each collection moment; Indicates Current adjustment trend at each acquisition moment; Represents a linear normalization function, which takes the linear normalization value in brackets; Indicates The time interval between the previous collection time and the current collection time.

[0100] The same method can be used to obtain the comprehensive impact weight of any electric vehicle charging pile in the electric vehicle charging area at any collection time.

[0101] The comprehensive impact weight of each electric vehicle charging pile in the electric vehicle charging area at each historical moment in the local time period is taken as the impact weight of the electric vehicle charging pile at the historical moment. The autoregressive integrated moving average model ARIMA is used to obtain the predicted value of the current at the next collection moment according to the current collected by all electric vehicle charging piles in the electric vehicle charging area at all historical moments in the local time period.

[0102] The predicted value is input into the PID controller to obtain the current control instruction at the next collection moment of the current at the current collection moment, and the current at the next collection moment of the current at the current collection moment is controlled according to the current control instruction.

[0103] The specific control process is: set the initial parameters of the proportional term, integral term, and differential term in the PID control to 0.2, 0.45, and 0.6 respectively; secondly, calculate the difference between the control coefficient of the proportional term at each acquisition moment and the control coefficient of the proportional term at the previous acquisition moment adjacent to each acquisition moment; take the sum of the control coefficient of the proportional term at each acquisition moment and the difference as the proportional term of the next moment of the last moment in each acquisition moment; take the comprehensive influence weight of each acquisition moment as input, and use the PID algorithm to output the current control instruction. It should be noted that in order to avoid the problem of too slow response of the control system due to too small value of the proportional term, the lower limit of the proportional term is set to 0.4.

[0104] At this point, current control for electric vehicle charging is achieved.

[0105] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for controlling charging of an electric vehicle in multiple application scenarios, characterized in that: The method comprises the following steps: At each collection moment, the temperature and current of the electric vehicle charging pile are collected respectively, and any electric vehicle charging pile in the electric vehicle charging area is recorded as a target electric vehicle charging pile. According to the change trend of the current of the target electric vehicle charging pile over time, the current of the target electric vehicle charging pile is grouped into different current stage sequences; the collection moment includes the current collection moment and a preset number of historical moments before; According to the difference between the current value contained in the current stage sequence and the current change trend, determine the current trend error at the collection time corresponding to the current contained in the current stage sequence, determine the first extreme value moment and the second extreme value moment of the collection time according to the temperature change trend at different collection times before and after the collection time, determine the temperature fluctuation at any collection time according to the current trend error, the first extreme value moment and the second extreme value moment of the target electric vehicle charging pile at any collection time, and obtain the initial influence weight of the target electric vehicle charging pile at any collection time according to the total number of electric vehicle charging piles, the current of all electric vehicle charging piles at all collection times and the temperature fluctuation of the target electric vehicle charging pile at any collection time; According to the overall change trend of the current of all electric vehicle charging piles at different collection times in the local time period and the instantaneous change trend at the collection time, the current adjustment trend at the collection time is determined; According to the initial impact weight of the target electric vehicle charging pile at the historical moment in the local time period, the current adjustment trend, and the time interval between the historical moment and the current collection moment, the current control of the electric vehicle charging is realized.

2. The method for controlling charging of an electric vehicle in multiple application scenarios according to claim 1, characterized in that: The specific method of forming the current of the target electric vehicle charging pile into a sequence of different current stages includes: Performing curve fitting on the order of the currents contained in the current sequence of the target electric vehicle charging pile and the current to obtain a current fitting curve; The value greater than 0.2 is recorded as the first case, the value less than -0.2 is recorded as the second case, and the value greater than or equal to -0.2 and less than or equal to 0.2 is recorded as the third case; Obtain the slope of the current fitting value corresponding to each order in the current sequence according to the current fitting curve, arrange all the slopes in order from small to large, and when the continuous slopes are the same in the first case, the second case or the third case, divide these continuous slopes into the same current stage sequence; When a continuous slope shows any case except the case where they are all the same one among the first case, the second case and the third case, the slope showing any case except the case where they are all the same one among the first case, the second case and the third case will be divided into the next current stage sequence until all the currents in the current sequence are divided into the current stage sequence.

3. The method for controlling electric vehicle charging in multiple application scenarios according to claim 1, characterized in that: The current trend error at the acquisition moment is determined by: Performing curve fitting on the order of the currents contained in the current phase sequence and the currents to obtain a current phase fitting curve; For any acquisition moment, the absolute value of the difference between the current corresponding to the acquisition moment and the current fitting value corresponding to the current stage fitting curve at the acquisition moment is recorded as the current trend error at the acquisition moment.

4. The method for controlling electric vehicle charging in multiple application scenarios according to claim 1, characterized in that: The specific method for determining the first extreme value moment and the second extreme value moment of the acquisition moment is: Arrange all the temperatures of the target electric vehicle charging pile at and before the current collection time in the order of the collection time to obtain the temperature sequence of the target electric vehicle charging pile, perform curve fitting on the order of the temperatures contained in the temperature sequence of the target electric vehicle charging pile and the temperatures, obtain the temperature fitting curve, and obtain the collection time corresponding to all extreme value points of the temperature fitting curve; For each collection moment, the collection moment corresponding to the latest extreme value point earlier than the collection moment is recorded as the first extreme value moment of the collection moment, and the collection moment corresponding to the earliest extreme value point later than the collection moment is recorded as the second extreme value moment of the collection moment.

5. The method for controlling charging of an electric vehicle in multiple application scenarios according to claim 4, characterized in that: The temperature fluctuation degree at the acquisition time includes the following specific methods: The absolute value of the difference between the temperature fitting values ​​corresponding to the second extreme value moment and the first extreme value moment of the target electric vehicle charging pile at the same collection moment is recorded as the first difference at the same collection moment; The difference between the second extreme value moment and the first extreme value moment of the target electric vehicle charging pile at the same collection moment is recorded as the second difference at the same collection moment; Record the ratio of the first difference value to the second difference value at the same acquisition moment as the first ratio at the same acquisition moment; The product of the first ratio at the same acquisition time and the current trend error of the target electric vehicle charging pile at the same acquisition time is recorded as the temperature fluctuation of the target electric vehicle charging pile at the same acquisition time.

6. The method for controlling charging of an electric vehicle in multiple application scenarios according to claim 1, characterized in that: The method of obtaining the initial influence weight of the target electric vehicle charging pile at any collection time according to the total number of electric vehicle charging piles, the current of all electric vehicle charging piles at all collection times, and the temperature fluctuation of the target electric vehicle charging pile at any collection time includes: The cumulative sum of the currents of all the electric vehicle charging piles at the same collection time is recorded as the cumulative current of the electric vehicle charging piles at the same collection time; The number of electric vehicle charging piles whose current of the charging interface is not 0 at the same collection time is recorded as the number of electric vehicle charging piles charging at the same collection time, and the ratio of the number of electric vehicle charging piles charging at any collection time to the total number of electric vehicle charging piles in the electric vehicle charging area is recorded as the second ratio at any collection time; The maximum value of the accumulated current of the electric vehicle charging pile at any one collection time and the accumulated current of the electric vehicle charging pile at all collection times is recorded as the third ratio at any one collection time; The product of the second ratio, the third ratio and the temperature fluctuation of the target electric vehicle charging pile at any collection time is recorded as the initial influence weight of any collection time.

7. The method for controlling electric vehicle charging in multiple application scenarios according to claim 6, characterized in that: The current adjustment trend at the collection time is determined according to the overall change trend of the current of all electric vehicle charging piles at different collection times in the local time period and the instantaneous change trend at the collection time, and the specific method includes: The accumulated currents of the electric vehicle charging piles are arranged in the order of the collection time to obtain an accumulated current sequence, and the order of the accumulated currents in the accumulated current sequence is subjected to curve fitting with the accumulated currents contained in the accumulated current sequence to obtain an accumulated current fitting curve; Fitting curve according to accumulated current; The absolute value of the slope of the straight line determined by two adjacent extreme value points on the cumulative current fitting curve is recorded as the overall current trend of all acquisition moments within the time period determined by the two adjacent extreme value points; The slope of the point corresponding to the accumulated current in the accumulated current sequence on the accumulated current fitting curve is recorded as the current trend at the time of the accumulated current collection; According to the accumulated current, overall current trend and momentary current trend of the electric vehicle charging pile at the time of collection, the current adjustment trend at the time of collection is determined.

8. The method for controlling charging of an electric vehicle in multiple application scenarios according to claim 7, characterized in that: The current adjustment trend at the time of collection is determined according to the accumulated current, the overall current trend and the current trend at the time of collection of the electric vehicle charging pile, and the specific method includes: The product of the linear normalized value of the current trend of the electric vehicle charging pile at the collection time, the accumulated current of the electric vehicle charging pile and the overall current trend is recorded as the current adjustment trend at the collection time.

9. The method for controlling charging of an electric vehicle in multiple application scenarios according to claim 1, characterized in that: The current control of the electric vehicle charging is realized according to the initial impact weight of the target electric vehicle charging pile at the historical moment in the local time period, the current adjustment trend, and the time interval between the historical moment and the current collection moment, including the specific method of: The product of the initial impact weight of the target electric vehicle charging pile at the historical moment in the local time period and the current adjustment trend is recorded as the first product of the target electric vehicle charging pile at the historical moment, and the linear normalized value of the ratio of the time interval between the historical moment and the current collection moment and the first product of the target electric vehicle charging pile at the historical moment is recorded as the comprehensive impact weight of the target electric vehicle charging pile at the historical moment; According to the comprehensive influence weight of each electric vehicle charging pile in the electric vehicle charging area at each historical moment in a local time period, the current control of electric vehicle charging is realized.

10. The method for controlling charging of an electric vehicle in multiple application scenarios according to claim 9, characterized in that: The specific method of realizing the current control of electric vehicle charging according to the comprehensive influence weight of each electric vehicle charging pile in the electric vehicle charging area at each historical moment in a local time period is as follows: The predicted value is input into the PID controller to obtain the current control instruction at the next collection moment of the current at the current collection moment, and the current at the next collection moment of the current at the current collection moment is controlled according to the current control instruction.

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