Electric vehicle charging module scheduling method

Abstract

The invention discloses an electric vehicle charging module scheduling method. The method comprises the following steps: acquiring a charging demand of an accessed vehicle; the total number of modules needing to be charged is calculated in real time, and a final charging scheme is determined: according to the current battery state and the parameters of the charging modules, feasible series connection schemes of the number of series connection charging modules meeting the charging voltage requirement are obtained, and the voltage grade corresponding to each feasible series connection scheme is calculated; for each voltage level, obtaining a current interval for realizing soft switching, and obtaining a feasible series scheme of the number of parallel charging modules meeting the charging current requirement; and the feasible series connection scheme, the corresponding voltage level and the feasible parallel connection scheme construct final feasible schemes, the total number of finally needed charging modules is obtained for each final feasible scheme, and the final charging scheme is determined under the conditions that the number is smaller than the number of the charging modules currently provided by the charging pile and the loss is the lowest.

Description

Technical Field

[0001] This invention relates to the field of electric vehicle charging technology, and more specifically to a method for scheduling electric vehicle charging modules. Background Technology

[0002] As an energy replenishment device, the charging system is a key infrastructure for the large-scale promotion and application of new energy vehicles. The charging voltage level of the new generation of new energy vehicles has increased from 400V to 800V, but 400V systems are still widely used. Currently, the main problems facing electric vehicle charging systems include: 1) difficulty in achieving efficient output under fixed charging power and a wide output range; 2) low actual utilization rate of some charging piles.

[0003] Traditional electric vehicle (EV) charging employs a constant-voltage, constant-current charging strategy, primarily consisting of three stages: the pre-charging stage, where a small current slowly increases the low-voltage battery to avoid high-voltage shocks; the constant-current stage, where the charging current often uses 3C (three times the battery capacity) or even a larger constant current to charge the EV battery, causing the charging voltage to rise rapidly; and the constant-voltage charging stage, where the charging voltage reaches the constant-voltage value, and the charging current gradually decreases to 0.01C to complete charging. Throughout the entire charging process, the EV's battery terminal voltage varies significantly over a considerable range, while the current demand exhibits a wide variation from 3C (peak fast charging) to 0.01C (end charging).

[0004] To meet the high-power charging demands of electric vehicles, electric vehicle charging systems often employ a parallel approach with multiple charging modules outputting high current. However, this approach only satisfies the peak charging power requirement, resulting in the charging modules inevitably operating under light load conditions for extended periods throughout the charging process, leading to low system efficiency. Furthermore, the charging modules require an extremely wide output voltage range, which makes soft-switching difficult to implement.

[0005] Therefore, based on the modular approach, charging modules are centrally scheduled using a switching network to meet the changing charging demands of electric vehicles. This can be broadly categorized into two types: one adjusts the number of charging modules connected in parallel based on the charging power requirements of the electric vehicle's battery, but the voltage output range is still determined by the module's own voltage output capability; the other utilizes series-connected voltage boosting and parallel-connected current amplification of charging modules to meet the charging needs of the electric vehicle, thus freeing its voltage output range from being confined to the output voltage range of a single module. However, these charging schemes only allocate modules from the perspective of meeting the charging needs of the electric vehicle's battery, without considering the losses in the charging system itself, resulting in significant losses and low efficiency. Furthermore, when selecting charging modules, they are often simply chosen sequentially without considering issues such as the balanced lifespan of the modules. Summary of the Invention

[0006] In view of this, the present invention provides a method for scheduling electric vehicle charging modules, which at least solves the problem of high scheduling loss and low efficiency of charging modules during electric vehicle charging in the prior art.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A method for scheduling electric vehicle charging modules, applicable to charging systems with multiple charging modules, wherein the input terminals are connected to a DC bus via a common DC bus, the output terminals are connected to a switch matrix network, and the charging modules are connected in series, parallel, or series-parallel. The method includes the following steps: S1. Obtain the charging needs of connected vehicles; upon detecting an electric vehicle connecting to the charging station... After connecting to each charging port, the current battery status of the vehicle is obtained and the battery status is monitored in real time. S2. Calculate the total number of charging modules required in real time and determine the final charging scheme; S21. Based on the current battery status and the charging module's own parameters, obtain... Number of series charging modules that meet the charging voltage requirements Feasible series connection schemes, among which And calculate the voltage level corresponding to each feasible series scheme; S22. For each voltage level, obtain the current range for implementing soft switching. Number of parallel charging modules that meet the charging current requirements Feasible series connection schemes, among which ; S23. Construct the final feasible scheme by considering feasible series schemes, their corresponding voltage levels, and feasible parallel schemes. For each final feasible scheme, obtain the total number of charging modules required. Determine the final charging scheme based on the condition that it is less than the number of charging modules that the charging pile can currently provide and the loss is minimized.

[0008] Preferably, the battery status includes: S21 specifically includes: No. Number of series charging modules in a feasible series scheme The calculation method is as follows; ; In the formula, For the first The required voltage for each charging port to connect to an electric vehicle. and These are the minimum and maximum output voltages of a single charging module, respectively. Take a positive integer that satisfies the constraints; Then each The corresponding voltage level for: .

[0009] Preferably, the specific content of S22 includes: For each For each voltage level, calculate the first voltage level that meets the charging current requirement. Number of parallel charging modules in a feasible parallel scheme : ; In the formula, For the first Each charging port is connected to the electric vehicle's required current. and The first The charging module meets the minimum and maximum current values ​​for soft switching at each voltage level.

[0010] Preferably, the specific content of S23 includes: For each feasible solution, the final total number of charging modules required is obtained. : ; The final total number of charging modules required The final feasible solution with a number of charging modules less than that that the charging pile can currently provide is retained, and the loss of each retained final feasible solution is calculated. The solution with the lowest loss is taken as the final charging solution. If no viable solution is available in the final available options, then users will be placed in a queue to wait.

[0011] Preferably, it also includes: S3. Selecting a working module, the specific content of which includes: S31. Real-time acquisition of the cumulative working time and temperature data of the charging modules currently working in the charging gun and the idle charging modules in the charging pile; S32. After excluding the charging modules that exceed the temperature warning value, prioritize the remaining charging modules according to their historical cumulative working time, with the shorter the working time, the higher the priority. S33. Based on the final charging scheme determined in S2, select a charging module to complete the current charging task.

[0012] Preferably, the specific details of selecting the charging module in S33 include: Real-time determination of whether the final charging scheme determined by S2 at the current moment has changed compared to the charging structure at the current moment; If there is no change, check if there is a charging module in the current working charging module whose temperature has reached the warning value; if so, select the corresponding charging module according to priority to replace it; if not, continue to keep the charging module in the current working state. If there is a change, it is determined whether the number of charging modules in the final charging scheme determined by S2 is greater than the number of charging modules currently in operation. If so, the charging modules currently in operation and the remaining idle charging modules whose temperature has not reached the warning value are sorted according to priority. The charging modules with the highest priority and the corresponding number are selected to replace the charging modules currently in operation. The replaced charging modules are classified as idle modules.

[0013] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a method for scheduling electric vehicle charging modules, which has the following beneficial effects: 1) Select the charging scheme with the lowest loss. Utilize the charging pile system's ability to support flexible configuration of series-parallel or parallel connections. By adjusting the series-parallel combination of charging modules, the output voltage level can be changed. Combined with the differences in the soft-switching current output range of charging modules at different voltage levels, all feasible charging schemes are enumerated, and the scheme with the lowest system loss is selected for operation. This improves the energy conversion efficiency of the charging pile and reduces operating costs. 2) Dynamically allocate available charging modules. Instead of including all charging modules in the available range, the set of available modules is dynamically adjusted according to actual operating conditions to improve system responsiveness and resource utilization efficiency; 3) Charging module selection strategy. After dynamically adjusting the output voltage, current, and temperature warning thresholds of the charging modules based on the lowest loss scheme, priority is assigned to the modules according to their cumulative working time and real-time status. Corresponding module selection strategies are formulated for two scenarios: whether the charging scheme changes or not, to achieve efficient and reliable operation of the system. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 A topology diagram of an electric vehicle charging system provided in an embodiment of the present invention; Figure 2 The flowchart illustrates a method for scheduling electric vehicle charging modules provided by this invention. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] This invention provides a method for scheduling electric vehicle charging modules, applicable to charging systems with multiple charging modules, such as... Figure 1 As shown, the input terminal is connected to the DC bus via a common DC bus, and the output terminal is connected to a switch matrix network. The charging modules are connected in series, parallel, or series-parallel connections, as shown below. Figure 2 As shown, it includes the following steps: S1. Obtain the charging needs of connected vehicles; upon detecting an electric vehicle connecting to the charging station... After connecting to each charging port, the current battery status of the vehicle is obtained and the battery status is monitored in real time. S2. Calculate the total number of charging modules required in real time and determine the final charging scheme; S21. Based on the current battery status and the charging module's own parameters, obtain... Number of series charging modules that meet the charging voltage requirements Feasible series connection schemes, among which And calculate the voltage level corresponding to each feasible series scheme; S22. For each voltage level, obtain the current range for implementing soft switching. Number of parallel charging modules that meet the charging current requirements Feasible series connection schemes, among which ; S23. Construct the final feasible scheme by considering feasible series schemes, their corresponding voltage levels, and feasible parallel schemes. For each final feasible scheme, obtain the total number of charging modules required. Determine the final charging scheme based on the condition that it is less than the number of charging modules that the charging pile can currently provide and the loss is minimized.

[0018] To further implement the above technical solution, the battery status includes: S21 specifically includes: No. Number of series charging modules in a feasible series scheme The calculation method is as follows; ; In the formula, For the first The required voltage for each charging port to connect to an electric vehicle. and These are the minimum and maximum output voltages of a single charging module, respectively. Take a positive integer that satisfies the constraints; Then each The corresponding voltage level for: .

[0019] To further implement the above technical solution, the specific content of S22 includes: For each For each voltage level, calculate the first voltage level that meets the charging current requirement. Number of parallel charging modules in a feasible parallel scheme : ; In the formula, For the first Each charging port is connected to the electric vehicle's required current. and The first The charging module meets the minimum and maximum current values ​​for soft switching at each voltage level.

[0020] To further implement the above technical solution, the specific content of S23 includes: For each feasible solution, the final total number of charging modules required is obtained. : ; The final total number of charging modules required The final feasible solution with a number of charging modules less than that that the charging pile can currently provide is retained, and the loss of each retained final feasible solution is calculated. The solution with the lowest loss is taken as the final charging solution. If no viable solution is available in the final available options, then users will be placed in a queue to wait.

[0021] To further implement the above technical solution, it also includes: S3. Selecting a working module, the specific contents of which include: S31. Real-time acquisition of the cumulative working time and temperature data of the charging modules currently working in the charging gun and the idle charging modules in the charging pile; S32. After excluding the charging modules that exceed the temperature warning value, prioritize the remaining charging modules according to their historical cumulative working time, with the shorter the working time, the higher the priority. S33. Based on the final charging scheme determined in S2, select a charging module to complete the current charging task.

[0022] To further implement the above technical solution, the specific details of selecting the charging module in S33 include: Real-time determination of whether the final charging scheme determined by S2 at the current moment has changed compared to the charging structure at the current moment; If there is no change, check if there is a charging module in the current working charging module whose temperature has reached the warning value; if so, select the corresponding charging module according to priority to replace it; if not, continue to keep the charging module in the current working state. If there is a change, it is determined whether the number of charging modules in the final charging scheme determined by S2 is greater than the number of charging modules currently in operation. If so, the charging modules currently in operation and the remaining idle charging modules whose temperature has not reached the warning value are sorted according to priority. The charging modules with the highest priority and the corresponding number are selected to replace the charging modules currently in operation. The replaced charging modules are classified as idle modules.

[0023] It should be noted that: In actual use, after the electric vehicle plugs in the charging gun, the required number of charging modules is calculated based on the current battery status of the vehicle and the battery status is monitored in real time. The corresponding number of charging modules are selected according to priority. After all the selected charging modules have been started, the matrix switch network is switched to use the charging structure with the lowest loss to charge the electric vehicle battery. During the operation of the charging modules, new charging schemes are obtained in real time according to S2 until the current electric vehicle is fully charged.

[0024] The present invention will be described below through specific embodiments: Taking a voltage and current requirement of 800V and 100A as an example, if a charging module outputs 200-400V, then the number of charging modules connected in series can be 2, 3, or 4. , , The corresponding voltage level , and .

[0025] In the first feasible series scheme Corresponding voltage level In the case of charging module achieving module current, assuming The current rating is 25-50A, and the number of charging modules connected in parallel can be 2, 3, or 4. , , Therefore, the final feasible solution is 1: , Number of parallel charging modules Final feasible option 2: , Number of parallel charging modules Final feasible solution 3: , Number of parallel charging modules .

[0026] In the second feasible series scheme Corresponding voltage level In the case of charging module achieving module current, assuming The current rating is 20-50A, and the number of charging modules connected in parallel can be 2, 3, 4, or 5. , , , Therefore, the final feasible solution is 4: , Number of parallel charging modules Final feasible option 5: , Number of parallel charging modules Final Feasible Solution 6: , Number of parallel charging modules Final Feasible Solution 7: , Number of parallel charging modules .

[0027] The same logic applies to all charging solutions.

[0028] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for scheduling electric vehicle charging modules, applicable to charging systems with multiple charging modules, wherein the input terminals are connected to a DC bus via a common DC bus, the output terminals are connected to a switch matrix network, and the charging modules are connected in series, parallel, or series-parallel; characterized in that... Includes the following steps: S1. Obtain the charging needs of connected vehicles; upon detecting an electric vehicle connecting to the charging station... After connecting to each charging port, the current battery status of the vehicle is obtained and the battery status is monitored in real time. S2. Calculate the total number of charging modules required in real time and determine the final charging scheme; S21. Based on the current battery status and the charging module's own parameters, obtain... Number of series charging modules that meet the charging voltage requirements Feasible series connection schemes, among which And calculate the voltage level corresponding to each feasible series scheme; S22. For each voltage level, obtain the current range for implementing soft switching. Number of parallel charging modules that meet the charging current requirements Feasible series connection schemes, among which ; S23. Construct the final feasible scheme by considering feasible series schemes, their corresponding voltage levels, and feasible parallel schemes. For each final feasible scheme, obtain the total number of charging modules required. Determine the final charging scheme based on the condition that it is less than the number of charging modules that the charging pile can currently provide and the loss is minimized.

2. The electric vehicle charging module scheduling method according to claim 1, characterized in that, Battery status includes: The specific details of S21 include: No. Number of series charging modules in a feasible series scheme The calculation method is as follows; ； In the formula, For the first The required voltage for each charging port to connect to an electric vehicle. and These are the minimum and maximum output voltages of a single charging module, respectively. Take a positive integer that satisfies the constraints; Then each The corresponding voltage level for: 。 3. The electric vehicle charging module scheduling method according to claim 1, characterized in that, The specific content of S22 includes: For each For each voltage level, calculate the first voltage level that meets the charging current requirement. Number of parallel charging modules in a feasible parallel scheme : ； In the formula, For the first Each charging port is connected to the electric vehicle's required current. and The first The charging module meets the minimum and maximum current values ​​for soft switching at each voltage level.

4. The electric vehicle charging module scheduling method according to claim 1, characterized in that, The specific content of S23 includes: For each feasible solution, the final total number of charging modules required is obtained. : ； The final total number of charging modules required The final feasible solution with a number of charging modules less than that currently available from the charging pile is retained, and the loss of each retained final feasible solution is calculated. The solution with the lowest loss is taken as the final charging solution. If no viable solution is available in the final available options, then users will be placed in a queue to wait.

5. The electric vehicle charging module scheduling method according to claim 1, characterized in that, Also includes: S3. Select the working module, which includes: S31. Real-time acquisition of the cumulative working time and temperature data of the charging modules currently working in the charging gun and the idle charging modules in the charging pile; S32. After excluding the charging modules that exceed the temperature warning value, prioritize the remaining charging modules according to their historical cumulative working time, with the shorter the working time, the higher the priority. S33. Based on the final charging scheme determined in S2, select a charging module to complete the current charging task.

6. The electric vehicle charging module scheduling method according to claim 5, characterized in that, The specific details of selecting the charging module in S33 include: Real-time determination of whether the final charging scheme determined by S2 at the current moment has changed compared to the charging scheme currently in operation; If there is no change, check if there is a charging module in the current working charging module whose temperature has reached the warning value; if so, select the corresponding charging module according to priority to replace it; if not, continue to keep the charging module in the current working state. If there is a change, it is determined whether the number of charging modules in the final charging scheme determined by S2 is greater than the number of charging modules currently in operation. If so, the charging modules currently in operation and the remaining idle charging modules whose temperature has not reached the warning value are sorted according to priority. The charging modules with the highest priority and the corresponding number are selected to replace the charging modules currently in operation. The replaced charging modules are classified as idle modules.

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