A hybrid grid and battery input electric vehicle charging system

Abstract

The application discloses a kind of electric vehicle charging systems of grid and battery hybrid input, including distribution network circuit, distribution transformer, low-voltage bus, rectifier, battery pack, control unit and charging pile and server unit;Wherein distribution network circuit is divided into two ways, wherein A road alternating current is converted into direct current by rectifier after being transmitted to low-voltage bus by distribution transformer, and is sent to battery pack, and battery pack is charged, and battery pack exports electric energy to control unit, B road alternating current is converted into direct current by rectifier after being transmitted to low-voltage bus by distribution transformer, and is exported to controller;Controller controls the proportion of battery pack and direct current input according to the control strategy of server unit, and electric energy is delivered to charging pile.The technical scheme of the application reasonably arranges electric vehicle charging method and charging order according to main distribution network capacity, so as to effectively control and optimize main distribution network load of power grid, reduce the risk and noise of equipment overload.

Description

Technical Field

[0001] This invention belongs to the field of electric vehicle charging, and specifically relates to an electric vehicle charging system with a hybrid input of power grid and battery. Background Technology

[0002] With the gradual promotion of electric vehicles, electric vehicle charging has become very common. Currently, electric vehicle users generally charge their vehicles through ordinary household power sources and charging stations. However, as the number of electric vehicles increases, the impact of unregulated electric vehicle charging behavior on the power grid is also increasing.

[0003] The simultaneous charging of a large number of electric vehicles will impact the operation of the power grid and cause equipment overload; since electric vehicle charging is often concentrated in a certain period of time, simply increasing the capacity of the main and distribution network equipment will result in a large waste of funds; at the same time, charging will also generate a lot of noise, affecting the normal life of residents.

[0004] Therefore, an electric vehicle charging system is needed to regulate the charging behavior of electric vehicles. Summary of the Invention

[0005] The purpose of this invention is to provide an electric vehicle charging system with a hybrid input of power grid and battery, which rationally arranges the electric vehicle charging method and charging sequence according to the capacity of the main and distribution networks, thereby effectively controlling the load of the main and distribution networks and reducing the risk of equipment overload and noise.

[0006] The technical solution to achieve the purpose of this invention is as follows:

[0007] An electric vehicle charging system with hybrid input from the power grid and batteries includes distribution network lines, distribution transformers, low-voltage busbars, rectifiers, battery packs, control units, charging piles, and server units.

[0008] The distribution network line divides the AC power into two paths. Path A AC power is transmitted to the low-voltage bus after passing through the distribution transformer, and then converted into DC power by the rectifier and sent to the battery pack to charge the battery pack. The battery pack then outputs electrical energy to the control unit.

[0009] The AC power from circuit B is transmitted to the low-voltage bus via the distribution transformer and then converted into DC power by the rectifier before being output to the control unit.

[0010] The control unit controls the ratio of battery pack and DC power input according to the control strategy of the server unit, and delivers electrical energy to the charging pile.

[0011] Furthermore, it also includes line power measuring devices, distribution transformer power measuring devices, charging pile power measuring devices, and substation line switches;

[0012] The substation line switch is installed on the distribution network line, and the line power measurement device is used to collect the power flowing through the substation line switch and transmit it to the server unit.

[0013] The power measurement device for distribution transformers is used to collect the power flowing through the two distribution transformers and transmit it to the server unit.

[0014] The charging pile power measurement device is used to collect the power flowing through the charging pile and transmit it to the server unit.

[0015] Furthermore, the server unit includes a server, distribution transformer and topology monitoring, and line monitoring;

[0016] The line power measurement device transmits the collected power flowing through the substation line switches to the line monitoring of the server unit.

[0017] The power measurement device for distribution transformers transmits the collected power flowing through the two distribution transformers to the server unit for distribution transformer and topology monitoring.

[0018] The server determines whether the increase in charging will cause the line to overload based on the line load data and equipment parameter information monitored by the line monitoring system, and collects the historical load curve of the line for overload identification in the peak load time period of the line.

[0019] The server determines whether the increase in charging will cause the transformer to overload based on the transformer load data and equipment parameter information monitored by the transformer and topology. It collects the historical load curve of the transformer for overload prediction and identification in the peak load time period of the line. It collects the distribution network topology to correctly associate the correspondence between the transformer and the line when the power grid operation mode changes, and to determine whether the increase in charging during simultaneous charging will cause overload.

[0020] The server determines the charging strategy based on the output distribution strategy and the load control strategy, and sends the ratio of battery pack and DC input to the control unit.

[0021] Furthermore, the process by which the server determines the charging strategy based on the output allocation strategy and the load control strategy is as follows:

[0022] S1. When a charging demand is generated, obtain the line load data and the distribution network transformer load data, determine the increment of the charging demand, and determine whether either the load rate at the time of access or the stage load rate exceeds a. If so, determine that the charging behavior exceeds the load rate a.

[0023] S2. Determine the ratio of battery pack to DC input based on the load rate.

[0024] Compared with the prior art, the significant advantages of this invention are:

[0025] (1) The electric vehicle charging system of the present invention, which integrates grid and battery input, uses the load of distribution network line equipment as a basis, and uses the load rate at the time of access and the stage load rate to determine the system load rate. Based on the load rate, the system controls the input ratio of grid DC power and battery pack to reasonably arrange electric vehicle charging, thereby optimizing the load of the line and distribution network and effectively avoiding the risk of equipment overload.

[0026] (2) The electric vehicle charging system of the present invention, which integrates power grid and battery input, controls the charging order of customers by judging the load rate and setting a corresponding price adjustment strategy based on the load rate, effectively controlling the load of the power grid and leaving sufficient power consumption margin and load change margin for the power grid.

[0027] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the electric vehicle charging system structure of the present invention, which uses a hybrid input of power grid and battery. Figure 1 .

[0029] Figure 2 This is a schematic diagram of the electric vehicle charging system structure of the present invention, which uses a hybrid input of power grid and battery. Figure 2 .

[0030] Figure 3 This is a schematic diagram of the control unit circuit in one embodiment of the electric vehicle charging system with hybrid input of the power grid and battery according to the present invention.

[0031] Figure 4 This is a schematic diagram of control signals for a control unit in one embodiment of an electric vehicle charging system with a hybrid input of power grid and battery according to the present invention.

[0032] Figure 5 This is a schematic diagram illustrating the stage load rate calculation in one embodiment of the electric vehicle charging system with hybrid input of power grid and battery according to the present invention.

[0033] Figure 6 This is a schematic diagram of the power grid topology in one embodiment of the electric vehicle charging system with hybrid power grid and battery input according to the present invention.

[0034] Figure 7 This is a schematic flowchart of one embodiment of the electric vehicle charging method of the present invention, which uses a hybrid input of the power grid and a battery. Detailed Implementation

[0035] An electric vehicle charging system with hybrid input of power grid and battery storage is characterized by comprising a distribution network line 4, a distribution transformer 6, a low-voltage busbar 7, a rectifier 8, a battery pack 9, a control unit 10, a charging pile 11, and a server unit.

[0036] The distribution network line 4 divides the AC power into two paths. The AC power in path A is transmitted to the low-voltage bus 7 through the distribution transformer 6 and then converted into DC power by the rectifier 8 and sent to the battery pack 9 to charge the battery pack 9. The battery pack 9 outputs electrical energy to the control unit 10.

[0037] The AC power from circuit B is transmitted to the low-voltage bus 7 via distribution transformer 6 and then converted to DC power by rectifier 8 before being output to control unit 10.

[0038] The control unit 10 controls the ratio of battery pack 9 and DC power input according to the control strategy of the server unit, and transmits electrical energy to charging pile 11.

[0039] Furthermore, the system also includes a line power measuring device 1, a distribution transformer power measuring device 2, a charging pile power measuring device 3, and a substation line switch 5;

[0040] The substation line switch 5 is installed on the distribution network line 4, and the line power measuring device 1 is used to collect the power flowing through the substation line switch 5 and transmit it to the server unit.

[0041] The power measurement device 2 is used to collect the power flowing through the two distribution transformers 6 and transmit it to the server unit;

[0042] The charging pile power measurement device 3 is used to collect the power flowing through the charging pile 11 and transmit it to the server unit.

[0043] The charging pile 11 is equipped with a scanning device. When a user needs to charge, the charging pile 11 scans the user's QR code and sends it to the server unit for verification before enabling the charging function.

[0044] Users can interact with the server unit through a mobile app to view the status of charging stations at their location, select a charging location and time, and after a successful reservation, the server unit will send a QR code to the user's mobile app. Users can then use the QR code to charge at the charging station.

[0045] The server unit receives the QR code verification request from the charging pile 11, opens the charging function, and the charging pile 11 uploads the user's charging data and power to the server as the basis for user fee settlement.

[0046] Furthermore, the server unit includes a server 12, a distribution transformer and topology monitoring unit 13, and a line monitoring unit 14;

[0047] The line power measuring device 1 transmits the power collected from the substation line switch 5 to the line monitoring 14 of the server unit.

[0048] The power measurement device 2 transmits the collected power flowing through the two distribution transformers 6 to the distribution transformer and topology monitoring 13 of the server unit;

[0049] Server 12 determines whether the charging increment will cause line overload based on the line load data and equipment parameter information of line monitoring 14, and collects the historical load curve of the line for overload identification in the peak load time period of the line.

[0050] Server 12 determines whether the charging increment will cause the distribution transformer to overload based on the distribution transformer and topology monitoring 13's distribution transformer load data and equipment parameter information. It collects the distribution transformer's historical load curve for overload prediction and identification in the peak load time period of the line. It collects the distribution network topology for correctly associating the distribution transformer and line correspondence when the power grid operation mode changes, as well as judging whether the charging increment during simultaneous charging will cause overload.

[0051] Server 12 determines the charging strategy based on the output distribution strategy and load control strategy, and sends the ratio of battery pack 9 to DC input to control unit 10.

[0052] Furthermore, the process by which the server 12 determines the charging strategy based on the output allocation strategy and the load control strategy is as follows:

[0053] S1. When a charging demand is generated, obtain the line load data and the distribution network transformer load data, determine the increment of the charging demand, and determine whether either the load rate at the time of access or the stage load rate exceeds a. If so, determine that the charging behavior exceeds the load rate a.

[0054] Specifically, the load factor during access and the phased load factor are as follows:

[0055]

[0056] Among them, Q 线路 and Q 配变 S represents the load factor when the line and distribution transformer are connected, respectively. 线路 and S 配变 These represent the real-time load power of the line collected by server 12 and the real-time load power of the distribution network transformer, respectively. ΔS represents the load increment of this charging demand. 线路n and S 配变n These represent the rated power of the line and the distribution network transformer, respectively.

[0057]

[0058] Among them, T 线路and T 配变 S represents the stage load factor of the line and the distribution network transformer, respectively. 线路yc and S 配变yc S represents the predicted load of the line and the distribution transformer, respectively. kzt This represents the load curve of the line or distribution network transformer from yesterday, S. k平均 This represents the average deviation between yesterday's load curve and today's load curve for the line or distribution network transformer within the hour preceding the time t3 when charging demand occurs. t1 and t2 represent the hour preceding the time t3 when demand occurs. S kyc This indicates the maximum value of the predicted load curve for the line or distribution network transformer during the time period from the moment the charging demand occurs (t3) to one hour after connection (t4).

[0059] S2. Determine the ratio of battery pack 9 to DC input based on the load rate, specifically:

[0060] If the charging behavior does not exceed load rate a, then DC power will be used for charging in this case.

[0061] If the charging behavior exceeds the load rate a, then the battery pack 9 and the DC input will be charged simultaneously, and the ratio of the battery pack 9 and the DC input will be controlled so that the load rate is lower than a, but the input ratio of the battery pack 9 does not exceed b.

[0062] Meanwhile, during a certain time interval at the peak load yesterday, in order to keep the load rate below a, the battery pack 9 can be put into operation at 100%.

[0063] Furthermore, if the charging behavior exceeds load rate a but is less than load rate c, the charging demand is controlled by increasing the charging fee. If the user agrees to the fee adjustment, the battery pack 9 and DC input are charged simultaneously.

[0064] When charging is performed simultaneously using battery pack 9 and DC input, and the utilization rate of battery pack 9 reaches the upper limit, if either the load rate or the phase load rate of the charging demand exceeds the set upper limit, all new charging demands will be stopped.

[0065] Simultaneously, the server unit also collects the distribution network topology to determine whether the increase in charging will cause overload, specifically:

[0066] For an electric vehicle charging system that integrates all grid and battery inputs under a single line, any new charging demand that occurs within the time period between the submission of charging demand and the output of charging power is recorded as simultaneous charging.

[0067] For example, while a user submits a charging request in charging system 1 but charging has not yet commenced, a user also submits a charging request in charging system 2. When calculating the line load rates Q and T for charging system 2, the server unit should, based on the topology, confirm whether other charging systems on its line are simultaneously charging, and pre-incorporate the incremental information from charging system 1 into the line load, i.e.:

[0068]

[0069] When a user of the charging system abandons charging, the system will release the pre-added increment of the charging system 1.

[0070] In addition, in the electric vehicle charging system with a hybrid input of the power grid and the battery, the charging of battery pack 9 is scheduled during the off-peak hours of the night load curve. If the charging is not completed during the off-peak hours, it will be supplemented during the off-peak hours of the day.

[0071] A method for charging an electric vehicle using a hybrid input of grid and battery power, comprising the following steps:

[0072] Step 1: Collect load information, equipment parameters, and topology of power lines and distribution transformers in real time;

[0073] Step 2: When a charging demand is generated, obtain the line load data and distribution network transformer load data, determine the increment of the charging demand, and determine whether either the load rate at the time of access or the stage load rate exceeds 'a'. If so, determine that the charging behavior exceeds the load rate 'a' and proceed to step 3; otherwise, proceed to step 4.

[0074] The determined access load rate and phase load rate are as follows:

[0075]

[0076] Among them, Q 线路 and Q 配变 S represents the load factor when the line and distribution transformer are connected, respectively. 线路 and S 配变 These represent the real-time load power of the line collected by server 12 and the real-time load power of the distribution network transformer, respectively. ΔS represents the load increment of this charging demand. 线路n and S 配变n These represent the rated power of the line and the distribution network transformer, respectively.

[0077]

[0078] Among them, T 线路 and T 配变 S represents the stage load factor of the line and the distribution network transformer, respectively. 线路yc and S 配变ycS represents the predicted load of the line and the distribution transformer, respectively. kzt This represents the load curve of the line or distribution network transformer from yesterday, S. k平均 This represents the average deviation between yesterday's load curve and today's load curve for the line or distribution network transformer within the hour preceding the time t3 when charging demand occurs. t1 and t2 represent the hour preceding the time t3 when demand occurs. S kyc This indicates the maximum value of the predicted load curve for the line or distribution network transformer during the time period from the moment the charging demand occurs (t3) to one hour after connection (t4).

[0079] Step 3: Adjust the charging price in a timely manner according to the set pricing strategy and push notifications to users. If the user agrees to the price adjustment, determine the ratio of battery pack and DC power input based on the load rate, and use the battery pack and DC power to charge the electric vehicle. If the user does not agree to the price adjustment, end the charging process and proceed to step 5.

[0080] Specifically, determining the ratio of battery pack to DC input based on load is as follows:

[0081] If the charging behavior does not exceed load rate a, then DC power will be used for charging in this case.

[0082] If the charging behavior exceeds the load rate a, then the battery pack and DC input will be charged simultaneously, and the ratio of the battery pack and DC input will be controlled so that the load rate is lower than a, but the battery pack's input ratio does not exceed b.

[0083] Meanwhile, during a certain time interval at yesterday's peak load, in order to keep the load rate below a, the battery pack 9 can be put into operation at 100%.

[0084] Meanwhile, if the charging behavior exceeds load rate a but is less than load rate c, the charging demand will be controlled by increasing the charging fee. If the user agrees to the fee adjustment, the battery pack 9 and DC input will be used for charging simultaneously.

[0085] When charging is performed simultaneously using battery pack 9 and DC input, and the battery pack's usage ratio reaches the upper limit, if either the load rate at the time of connection or the stage load rate exceeds the set upper limit, all charging activities will be stopped and the charging system will suspend service.

[0086] Step 4: Charge the electric vehicle using direct current and complete the charging process;

[0087] Step 5, End.

[0088] When users need to charge, they can log in to the mobile app to check the status and capacity of each charging station. Users select the appropriate charging station and service, and the system calculates the power consumption and adjusts accordingly. If the power consumption does not exceed the limit, a charging QR code is sent to the user's phone, which the user can then scan at the charging station. If the power consumption exceeds the limit, a price adjustment message is displayed, awaiting user confirmation. If the user agrees to the adjustment, a charging QR code is sent to their phone, which they can then scan at the charging station. If the user does not agree, they can exit the app or choose a charging station in another area.

[0089] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0090] Example

[0091] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0092] Combination Figures 1 to 2 An electric vehicle charging system with a hybrid input of power grid and battery storage is characterized by comprising a distribution network line 4, a distribution transformer 6, a low-voltage busbar 7, a rectifier 8, a battery pack 9, a control unit 10, a charging pile 11, and a server unit.

[0093] The distribution network line 4 divides the AC power into two paths. The AC power in path A is transmitted to the low-voltage bus 7 through the distribution transformer 6 and then converted into DC power by the rectifier 8 and sent to the battery pack 9 to charge the battery pack 9. The battery pack 9 outputs electrical energy to the control unit 10.

[0094] The AC power from circuit B is transmitted to the low-voltage bus 7 via distribution transformer 6 and then converted to DC power by rectifier 8 before being output to controller 10.

[0095] The controller 10 controls the ratio of battery pack 9 and DC power input according to the control strategy of the server unit, and transmits electrical energy to charging pile 11.

[0096] Combination Figure 3 This is a schematic diagram of the control circuit of the controller 10 in this embodiment. Figure 3 In this diagram, VCC1 represents the battery power supply, VCC2 represents the direct input power supply converted by rectifier 8 to the direct input / output controller 10, IGBT is the switching control element, C is the filter capacitor, and R is the load.

[0097] The inputs of VCC1 and VCC2 are both controlled by IGBTs. When the control signal S1 is positive, IGBT1 is turned on, and the load R is powered by power supply VCC1. When the control signal S2 is positive, IGBT2 is turned on, and the load R is powered by power supply VCC2.

[0098] Control signals S1 and S2 cause IGBT1 and IGBT2 to be in opposite conduction states, that is: when IGBT1 is on, IGBT2 is off, and when IGBT1 is off, IGBT2 is on.

[0099] The proportion of time that signals S1 and S2 are on within one cycle T is the power input proportion. Figure 4 If S1 accounts for 25% of the power during cycle T1, then the power input of VCC1 accounts for 25%, and the power input of VCC1 accounts for 75%.

[0100] If S1 accounts for 75% of the power input during period T2, then the power input of VCC1 accounts for 75% of the power input, and the power input of VCC1 accounts for 25%.

[0101] This enables the adjustment of the input power ratio of the two power supplies.

[0102] Furthermore, the system also includes a line power measuring device 1, a distribution transformer power measuring device 2, a charging pile power measuring device 3, and a substation line switch 5;

[0103] The substation line switch 5 is installed on the distribution network line 4, and the line power measuring device 1 is used to collect the power flowing through the substation line switch 5 and transmit it to the server unit.

[0104] The power measurement device 2 is used to collect the power flowing through the two distribution transformers 6 and transmit it to the server unit;

[0105] The charging pile power measurement device 3 is used to collect the power flowing through the charging pile 11 and transmit it to the server unit.

[0106] The charging pile 11 is equipped with a scanning device. When a user needs to charge, the charging pile 11 scans the user's QR code and sends it to the server unit for verification before enabling the charging function.

[0107] Users can interact with the server unit through a mobile app to view the status of charging stations at their location, select a charging location and time, and after a successful reservation, the server unit will send a QR code to the user's mobile app. Users can then use the QR code to charge at the charging station.

[0108] The server unit receives the QR code verification request from the charging pile 11, opens the charging function, and the charging pile 11 uploads the user's charging data and power to the server as the basis for user fee settlement.

[0109] Furthermore, the server unit includes server 12, dispatch monitoring 14-D5000 master station, and distribution transformer and topology monitoring 13-D5200 master station;

[0110] The line power measuring device 1 transmits the collected power flowing through the substation line switch 5 to the D5000 master station of the server unit.

[0111] The power measurement device 2 transmits the collected power flowing through the two distribution transformers 6 to the D5200 master station of the server unit;

[0112] Server 12 determines whether the charging increment will cause line overload based on the line load data and equipment parameter information of line monitoring 14, and collects the historical load curve of the line for overload identification in the peak load time period of the line.

[0113] Server 12 determines whether the charging increment will cause the distribution transformer to overload based on the distribution transformer and topology monitoring 13's distribution transformer load data and equipment parameter information. It collects the distribution transformer's historical load curve for overload prediction and identification in the peak load time period of the line. It collects the distribution network topology for correctly associating the distribution transformer and line correspondence when the power grid operation mode changes, as well as judging whether the charging increment during simultaneous charging will cause overload.

[0114] Server 12 determines the charging strategy based on the output distribution strategy and load control strategy, and sends the ratio of battery pack 9 to DC input to control unit 10.

[0115] Furthermore, the process by which the server 12 determines the charging strategy based on the output allocation strategy and the load control strategy is as follows:

[0116] S1. When a charging demand is generated, obtain the line load data and the distribution network transformer load data, determine the increment of the charging demand, and determine whether either the load rate at the time of access or the stage load rate exceeds 70%. If so, determine that the charging behavior exceeds 70% load rate.

[0117] Among them, combined Figure 5 The load rate during access and the phased load rate are specifically as follows:

[0118]

[0119] Among them, Q 线路 and Q 配变 S represents the load factor when the line and distribution transformer are connected, respectively. 线路 and S 配变 These represent the real-time load power of the line collected by server 12 and the real-time load power of the distribution network transformer, respectively. ΔS represents the load increment of this charging demand. 线路n and S配变n These represent the rated power of the line and the distribution network transformer, respectively.

[0120]

[0121] Among them, T 线路 and T 配变 S represents the stage load factor of the line and the distribution network transformer, respectively. 线路yc and S 配变yc S represents the predicted load of the line and the distribution transformer, respectively. kzt This represents the load curve of the line or distribution network transformer from yesterday, S. k平均 This represents the average deviation between yesterday's load curve and today's load curve for the line or distribution network transformer within the hour preceding the time t3 when charging demand occurs. t1 and t2 represent the hour preceding the time t3 when demand occurs. S kyc This indicates the maximum value of the predicted load curve for the line or distribution network transformer during the time period from the moment the charging demand occurs (t3) to one hour after connection (t4).

[0122] S2. Determine the ratio of battery pack 9 to DC input based on the load rate, specifically:

[0123] If the charging activity does not exceed 70% of the load rate, then DC power will be used for charging in this instance.

[0124] If the charging behavior exceeds 70% load rate, then the battery pack 9 and DC input will be charged simultaneously, and the ratio of battery pack 9 and DC input will be controlled so that the load rate is below 70%, but the input ratio of battery pack 9 does not exceed 50%.

[0125] Meanwhile, during a certain time interval at yesterday's peak load, in order to keep the load rate below 70%, the battery pack 9 can be put into operation at 100%.

[0126] Furthermore, if the charging behavior exceeds 70% load rate but is less than 85% load rate, the charging demand will be controlled by increasing the charging fee. If the user agrees to the fee adjustment, the battery pack 9 and DC input will be charged simultaneously.

[0127] When charging is performed simultaneously using battery pack 9 and DC input, and the utilization rate of battery pack 9 reaches the upper limit, if either the load rate or the phase load rate of the charging demand exceeds the set upper limit, all new charging demands will be stopped.

[0128] Simultaneously, the server unit also collects the distribution network topology to determine whether the increase in charging will cause overload, specifically:

[0129] For an electric vehicle charging system that integrates all grid and battery inputs under a single line, any new charging demand that occurs within the time period between the submission of charging demand and the output of charging power is recorded as simultaneous charging.

[0130] For example, such as Figure 6 As shown, when switch 1 is closed and switch 2 is open, the charging system 3 is powered by the a outgoing switch of substation A, and the data of switch a is used to calculate the line load; when switch 1 is open and switch 2 is closed, the charging system 3 is powered by the b outgoing switch of substation B, and the data of switch b is used to calculate the line load.

[0131] Additionally, while a user submits a charging request for charging system 1 but charging has not yet commenced, a user also submits a charging request for charging system 2. When calculating the line load rates Q and T for charging system 2, the server unit should, based on the topology, confirm whether other charging systems on its line are simultaneously charging, and pre-incorporate the incremental information from charging system 1 into the line load calculation.

[0132]

[0133] When a user of the charging system abandons charging, the system will release the pre-added increment of the charging system 1.

[0134] In addition, in the electric vehicle charging system with a hybrid input of the power grid and the battery, the charging of battery pack 9 is scheduled during the off-peak hours of the night load curve. If the charging is not completed during the off-peak hours, it will be supplemented during the off-peak hours of the day.

[0135] Combination Figure 7 A method for charging an electric vehicle using a hybrid input of grid and battery power includes the following steps:

[0136] Step 1: Collect load information, equipment parameters, and topology of power lines and distribution transformers in real time;

[0137] Step 2: When a charging demand is generated, obtain the line load data and distribution network transformer load data, determine the increment of the charging demand, and determine whether either the load rate at the time of access or the phase load rate exceeds 70%. If so, determine that the charging behavior exceeds 70% load rate and proceed to step 3; otherwise, proceed to step 4.

[0138] The determined access load rate and phase load rate are as follows:

[0139]

[0140] Among them, Q 线路 and Q 配变 S represents the load factor when the line and distribution transformer are connected, respectively.线路 and S 配变 These represent the real-time load power of the line collected by server 12 and the real-time load power of the distribution network transformer, respectively. ΔS represents the load increment of this charging demand. 线路n and S 配变n These represent the rated power of the line and the distribution network transformer, respectively.

[0141]

[0142] Among them, T 线路 and T 配变 S represents the stage load factor of the line and the distribution network transformer, respectively. 线路yc and S 配变yc S represents the predicted load of the line and the distribution transformer, respectively. kzt This represents the load curve of the line or distribution network transformer from yesterday, S. k平均 This represents the average deviation between yesterday's load curve and today's load curve for the line or distribution network transformer within the hour preceding the time t3 when charging demand occurs. t1 and t2 represent the hour preceding the time t3 when demand occurs. S kyc This indicates the maximum value of the predicted load curve for the line or distribution network transformer during the time period from the moment the charging demand occurs (t3) to one hour after connection (t4).

[0143] Step 3: Adjust the charging price in a timely manner according to the set pricing strategy and push notifications to users. If the user agrees to the price adjustment, determine the ratio of battery pack and DC power input based on the load rate, and use the battery pack and DC power to charge the electric vehicle. If the user does not agree to the price adjustment, end the charging process and proceed to step 5.

[0144] Specifically, determining the ratio of battery pack to DC input based on load is as follows:

[0145] If the charging behavior does not exceed 70% load rate, then DC power will be used for charging in this case;

[0146] If the charging behavior exceeds 70% load rate, the battery pack and DC input will be charged simultaneously, and the ratio of battery pack to DC input will be controlled so that the load rate is below 70%, but the battery pack's input ratio does not exceed 50%.

[0147] Meanwhile, during a certain time interval at yesterday's peak load, in order to keep the load rate below 70%, the battery pack 9 can be put into operation at 100%.

[0148] Furthermore, if the charging behavior exceeds 70% load rate but is less than 85% load rate, the charging demand will be controlled by increasing the charging fee. If the user agrees to the fee adjustment, the battery pack 9 and DC input will be charged simultaneously.

[0149] When charging is performed simultaneously using battery pack 9 and DC input, and the proportion of battery pack 9 in operation reaches the upper limit, if either the load rate or the phase load rate of the charging demand exceeds the set upper limit, all new charging demands will be stopped to ensure sufficient power supply for normal residential use and to accommodate sudden load changes.

[0150] Step 4: Charge the electric vehicle using direct current and complete the charging process;

[0151] Step 5, End.

[0152] When users need to charge, they can log in to the mobile app to check the status and capacity of each charging station. Users select the appropriate charging station and service, and the system calculates the power consumption and adjusts accordingly. If the power consumption does not exceed the limit, a charging QR code is sent to the user's phone, which the user can then scan at the charging station. If the power consumption exceeds the limit, a price adjustment message is displayed, awaiting user confirmation. If the user agrees to the adjustment, a charging QR code is sent to their phone, which they can then scan at the charging station. If the user does not agree, they can exit the app or choose a charging station in another area.

[0153] As can be seen, the technical solution of this invention uses the load of the distribution network line equipment as a basis, and uses the load rate at the time of access and the phase load rate to determine the system load rate. Based on the load rate, it controls the input ratio of DC power from the power grid and the battery pack to reasonably arrange electric vehicle charging, thereby optimizing the load of the line and distribution network and effectively avoiding the risk of equipment overload. At the same time, by judging the load rate and setting corresponding price adjustment strategies based on the load rate, it controls the charging sequence of customers, effectively controls the load of the power grid, reduces noise, and also leaves sufficient power consumption margin and load change margin for the power grid.

[0154] The above embodiments illustrate and describe the basic principles and main features of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. An electric vehicle charging system with hybrid input from the power grid and a battery, characterized in that, It includes distribution network lines (4), distribution transformers (6), low-voltage busbars (7), rectifiers (8), battery packs (9), control units (10), charging piles (11), and server units; The distribution network line (4) divides the AC power into two paths. The AC power of path A is transmitted to the low-voltage bus (7) through the distribution transformer (6) and then converted into DC power by the rectifier (8) and sent to the battery pack (9) to charge the battery pack (9). The battery pack (9) outputs electrical energy to the control unit (10). The AC power from circuit B is transmitted to the low-voltage bus (7) via the distribution transformer (6) and then converted to DC power by the rectifier (8) and output to the control unit (10). The control unit (10) controls the ratio of battery pack (9) and DC input according to the control strategy of the server unit, and delivers electrical energy to the charging pile (11); It also includes a line power measuring device (1), a distribution transformer power measuring device (2), a charging pile power measuring device (3), and a substation line switch (5); The substation line switch (5) is installed on the distribution network line (4), and the line power measuring device (1) is used to collect the power flowing through the substation line switch (5) and transmit it to the server unit; The transformer power measurement device (2) is used to collect the power flowing through the two transformers (6) and transmit it to the server unit; The charging pile power measurement device (3) is used to collect the power flowing through the charging pile (11) and transmit it to the server unit; The server unit includes a server (12), a distribution transformer and topology monitoring (13), and a line monitoring (14); The line power measuring device (1) transmits the power collected from the substation line switch (5) to the line monitoring (14) of the server unit; The power measurement device (2) transmits the power collected from the two distribution transformers (6) to the distribution transformer and topology monitoring (13) of the server unit; The server (12) determines whether the charging increment will cause the line overload based on the line load data and equipment parameter information of the line monitoring (14), and collects the historical load curve of the line for overload identification in the peak load time period of the line. The server (12) judges whether the charging increment will cause the distribution transformer overload based on the distribution transformer and topology monitoring (13) distribution transformer load data and equipment parameter information, collects the distribution transformer historical load curve for overload prediction and identification of the peak load time segment of the line, and collects the distribution network topology for correctly associating the distribution transformer and line correspondence when the power grid operation mode changes, as well as judging whether the charging increment during simultaneous charging will cause overload. The server (12) determines the charging strategy based on the output distribution strategy and the load control strategy, and sends the ratio of the battery pack (9) and the DC input to the control unit (10); The process by which the server (12) determines the charging strategy based on the output allocation strategy and the load control strategy is as follows: S1. When a charging demand is generated, obtain the line load data and the distribution network transformer load data, determine the increment of the charging demand, and determine whether either the load rate at the time of access or the stage load rate exceeds a. If so, determine that the charging behavior exceeds the load rate a. S2. Determine the ratio of battery pack (9) to DC input based on the load rate; The access load rate and phase load rate in S1 are specifically as follows: Among them, Q 线路 and Q 配变 S represents the load factor when the line and distribution transformer are connected, respectively. 线路 and S 配变 These represent the real-time load power of the line collected by server (12) and the real-time load power of the distribution transformer, respectively. ΔS represents the load increment of this charging demand. 线路n and S 配变n These represent the rated power of the line and the distribution network transformer, respectively. Among them, T 线路 and T 配变 S represents the stage load factor of the line and the distribution network transformer, respectively. 线路yc and S 配变yc S represents the predicted load of the line and the distribution transformer, respectively. kzt This represents the load curve of the line or distribution network transformer from yesterday, S. k平均 This represents the average deviation between yesterday's load curve and today's load curve for the line or distribution network transformer within the hour preceding the time t3 when charging demand occurs. t1 and t2 represent the hour preceding the time t3 when demand occurs. S kyc This indicates the maximum value of the predicted load curve for the line or distribution network transformer during the time period from the moment the charging demand occurs (t3) to one hour after connection (t4).

2. The electric vehicle charging system with hybrid input of power grid and battery as described in claim 1, characterized in that, In S2, the ratio of battery pack (9) to DC input is determined based on the load, specifically as follows: If the charging behavior does not exceed load rate a, then DC power will be used for charging in this case. If the charging behavior exceeds the load rate a, then the battery pack (9) and DC input will be charged simultaneously, and the ratio of the battery pack (9) and DC input will be controlled so that the load rate is lower than a, but the input ratio of the battery pack (9) does not exceed b. Meanwhile, during a certain time interval at the peak load time yesterday, in order to keep the load rate below a, the battery pack (9) can be put into operation at 100%.

3. The electric vehicle charging system with hybrid input of power grid and battery as described in claim 2, characterized in that, If the charging behavior exceeds load rate a but is less than load rate c, the charging demand is controlled by increasing the charging fee. If the user agrees to the fee adjustment, the battery pack (9) and DC input are charged simultaneously. When charging is performed simultaneously using the battery pack (9) and DC input, and the battery pack (9) reaches its maximum capacity, if either the load rate or the phase load rate of the charging demand exceeds the set maximum capacity, then all new charging demands will be stopped.

4. A method for charging an electric vehicle using a hybrid input of power grid and battery, characterized in that, Includes the following steps: Step 1: Collect load information, equipment parameters, and topology of power lines and distribution transformers in real time; Step 2: When a charging demand is generated, obtain the line load data and distribution network transformer load data, determine the increment of the charging demand, and determine whether either the load rate at the time of access or the stage load rate exceeds 'a'. If so, determine that the charging behavior exceeds the load rate 'a' and proceed to step 3; otherwise, proceed to step 4. The determined access load rate and phase load rate are specifically as follows: Among them, Q 线路 and Q 配变 S represents the load factor when the line and distribution transformer are connected, respectively. 线路 and S 配变 These represent the real-time load power of the line collected by server (12) and the real-time load power of the distribution transformer, respectively. ΔS represents the load increment of this charging demand. 线路n and S 配变n These represent the rated power of the line and the distribution network transformer, respectively. Among them, T 线路 and T 配变 S represents the stage load factor of the line and the distribution network transformer, respectively. 线路yc and S 配变yc S represents the predicted load of the line and the distribution transformer, respectively. kzt This represents the load curve of the line or distribution network transformer from yesterday, S. k平均 This represents the average deviation between yesterday's load curve and today's load curve for the line or distribution network transformer within the hour preceding the time t3 when charging demand occurs. t1 and t2 represent the hour preceding the time t3 when demand occurs. S kyc This represents the maximum value of the predicted load curve for the line or distribution network transformer during the time period from the moment the charging demand occurs (t3) to one hour after connection (t4). Step 3: Adjust the charging price in a timely manner according to the set pricing strategy and push notifications to users. If the user agrees to the price adjustment, determine the ratio of battery pack and DC power input according to the load rate, and use the battery pack and DC power to charge the electric vehicle. If the user does not agree to the price adjustment, end the charging and proceed to step 5. Step 4: Charge the electric vehicle using direct current and complete the charging process; Step 5, End.

5. The electric vehicle charging method with hybrid input of power grid and battery as described in claim 4, characterized in that, The step 3, determining the ratio of battery pack to DC input based on the load, specifically involves: If the charging behavior does not exceed load rate a, then DC power will be used for charging in this case. If the charging behavior exceeds the load rate a, then the battery pack and DC input will be charged simultaneously, and the ratio of the battery pack and DC input will be controlled so that the load rate is lower than a, but the battery pack's input ratio does not exceed b. Meanwhile, during a certain time interval at the peak load time yesterday, in order to make the load rate lower than a, the battery pack (9) can be put into operation at 100%. Meanwhile, if the charging behavior exceeds load rate a but is less than load rate c, the charging demand is controlled by increasing the charging fee. If the user agrees to the fee adjustment, the battery pack (9) and DC input are charged simultaneously. When charging is performed simultaneously using the battery pack (9) and DC input, and the battery pack (9) reaches its maximum capacity, if either the load rate or the phase load rate of the charging demand exceeds the set maximum capacity, then all new charging demands will be stopped.

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