A multi-dc charging pile adaptive online method

Abstract

The application discloses a kind of multi direct current charging pile adaptive on-line method, belong to direct current charging pile technical field, comprising: the charging pile needing on-line is connected, and on-line mode is set;The charging pile of on-line respectively carries out self-checking;If charging pile self-checking is normal, then execute joint self-checking;When the charging pile passing joint self-checking fails, execute fault strategy;When on-line power exceeds charging gun gun line rated power, limit the maximum output power of charging gun;The multi direct current charging pile adaptive on-line method, when current single machine output power cannot satisfy the demand of car end, broadcast to find whether there is idle power module for use in on-line pile;After on-line parameter setting is completed, self-broadcast constructs on-line topology, improves single machine output power, on the basis of guaranteeing charging safety and reliability, idle power module of on-line charging pile is reasonably called, effectively improves charging efficiency.

Description

Technical Field

[0001] This invention belongs to the field of DC charging pile technology, specifically relating to an adaptive online method for multiple DC charging piles. Background Technology

[0002] DC charging piles, as electric vehicle charging devices, convert AC power to DC power and output it to the car battery at a higher power. Currently, to increase the output power of a single charging gun, DC charging piles mainly adopt a multi-module design approach, that is, increasing the rated power of a single unit by stacking power modules, thereby improving the output of a single charging gun. However, the charging process of an electric vehicle is dynamic; as the battery's System-on-Chips (SoC) increases, the power demand from the vehicle constantly changes. Currently, to protect the battery and extend its lifespan, most electric vehicles exit fast charging mode and switch to slow charging mode when the battery SoC is above 80%, resulting in a decrease in the utilization rate of the power modules. To address this, many power distribution or flexible charging methods have been proposed, allowing the charging pile to dynamically switch power modules based on the power demand received by each charging gun from the vehicle.

[0003] Due to the unpredictable nature of charging station usage, utilization rates vary significantly throughout the month and even within a single day, with queues forming even at large charging stations. Furthermore, under these supply-demand imbalances, some charging stations experience situations where vehicles are nearing the end of the charging process, requesting lower power, or some modules remain dormant. Simultaneously, with advancements in battery technology, vehicles supporting higher charging power are becoming increasingly common. However, the lifespan of a charging station after construction is typically around 10 years. For cost reasons, charging station service providers rarely upgrade existing facilities, failing to keep pace with vehicle charging power demands. This leads to issues such as low utilization rates due to charging station modules switching to dormancy at the end of the charging process and the high cost of expanding existing charging stations. Therefore, a new adaptive multi-DC charging station interconnection method is needed to address these problems. Summary of the Invention

[0004] The purpose of this invention is to provide an adaptive online method for multiple DC charging piles to solve the above-mentioned problems.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an adaptive online method for multiple DC charging piles, comprising:

[0006] A set of CAN communication lines, a set of output cables, and a set of joint contactors are added between the connected charging piles. The connection parameters are set through the human-machine interface (HMI interface) or remote control and sent to the SECC. The SECC senses, builds, and maintains the connection topology.

[0007] Based on the installation layout of the charging piles at the charging station, a chain-type or ring-type interconnection structure is selected; a CAN communication line is added between the SECCs of each charging pile to build an interconnection communication topology; a set of joint contactors and output cables is added between each charging pile to build an interconnection output topology and complete the electrical interconnection setup; a set of joint contactors and output cables includes two joint contactors and two output cables, and each cable requires one contactor;

[0008] The parameters for single-pile connectivity can be set through the HMI interface or remote control, including whether to enable connectivity, connectivity topology, maximum number of connected units, and current charging pile ID. These parameters are then transmitted to the SECC, which communicates with adjacent charging piles via the CAN bus to construct the topology.

[0009] Each connected charging station performs a self-test;

[0010] If the charging pile self-test is normal, then perform a joint self-test.

[0011] When a charging station that has passed the joint self-test fails, a fault policy is executed.

[0012] When the connected power exceeds the rated power of the charging gun cable, the maximum output power of the charging gun is limited.

[0013] Preferably, each connected charging station performs a self-test, executing the following steps:

[0014] With N i This indicates that the current charging station is the i-th charging station out of a total of N connected charging stations, with N being the number of charging stations connected. ia Let A represent the charging gun of the i-th charging station, and N represent the charging guns of the i-th charging station. ib Let B represent the charging gun of the i-th charging station, and K represent the charging gun of the i-th charging station. ia_out N represents i The charging gun A of the charging pile connects to the first output contactor of the power module, controlling the power module's power output to the charging gun A, in order to K i_m1m2 N represents i The parallel contactor between power modules M1 and M2 of the charging pile controls the on / off state of adjacent power modules. First, it sequentially controls the closing and opening of all output contactors and the parallel contactor, reading the feedback signal of each contactor. When the feedback signal matches the control state, the contactor's action detection passes; otherwise, a corresponding fault is triggered. Then, K is closed. ia_out The contactor and all parallel contactors, the SECC of the i-th charging pile sends a discharge command to all power modules of the pile, and reads whether the voltage of the meter of charging gun A is consistent with the voltage of the power module. If the values ​​are consistent, the self-test of charging gun A is passed; otherwise, charging gun A triggers a fault; the same applies to charging gun B.

[0015] Preferably, if the charging pile self-test is normal, a joint self-test is performed, which involves the following steps: the preceding charging pile controls the opening and closing of the joint contactor between the two piles and reads the contactor feedback signal; when the feedback signal matches the control state, the contactor test passes, otherwise the joint self-test fails; then the preceding charging pile closes the joint contactor between its right charging gun and the module of the following charging pile, and sends a power module discharge command to the SECC of the following charging pile via the CAN line, which wakes up the first power module to discharge. The purpose of this process is to check whether the cable between the two piles is properly connected; at this time, the preceding charging pile reads the voltage of the meter on the right charging gun and compares it with the voltage of the power module. If the voltages match, the joint self-test passes, otherwise the joint self-test fails; the control state is engaged / disengaged.

[0016] Preferably, when a charging pile that has passed the joint self-test fails, the following steps are performed: The charging pile that has failed will send fault information to the charging piles connected to the faulty charging gun according to the location of the faulty charging gun, and at the same time set the connection status of the link (output cable) to unavailable; After receiving the fault information, the adjacent charging pile will also update its own connection topology and set the connection status of the link to unavailable; When the faulty charging pile recovers, the charging pile will send charging gun information to the adjacent charging piles, and after receiving the information, the adjacent charging piles will re-perform the joint self-test with the charging pile, and after the joint self-test passes, the connection status of the link will be restored.

[0017] Preferably, when the online power exceeds the rated power of the charging gun cable, the following steps are performed: the OCPP limits the maximum output power of the charging gun according to the rated power of the charging gun cable and sends the limit value to the SECC. When the EVCC at the vehicle end requests power greater than the rated power of the charging gun cable, it outputs according to the maximum output power limit value of the charging gun.

[0018] Preferably, when constructing the topology: using K i_comb N represents i Charging piles and N i+1 The joint contactor between charging piles; when N i When the charging pile completes its self-test and enables online functionality, it sends a signal to N via the CAN bus. i+1 Charging station N i+1 The power module of the charging pile; during the joint self-test phase, first close N. ib Charging gun to N i+1a The joint contactor between charging guns is used to determine whether the joint contactor between individual charging piles can function properly; then, N is closed. ib Charging gun to N i+1a The joint contactor between the charging guns controls N. i+1 The charging pile power module discharges, by N ib The charging gun's meter reads the voltage data, N. iThe charging station SECC receives N via the CAN bus. i+1 The charging pile's SECC sends the power module discharge data and compares it with the data read from its own meter to determine if the voltage is consistent, and finally completes a joint self-test.

[0019] Preferably, after the topology is established, when N i+1a When the charging gun malfunctions, N i+1 The charging station will connect N via the CAN bus. i+1a Charging gun malfunction information is synchronized to N i Charging station, at this time N i The charging station will be placed at its own N ib The charging gun node is in an offline state, at which time N ib The charging gun will not charge N i+1 The charging station calls upon the power module; similarly, when N ib When the charging gun malfunctions, N i The charging station will connect N via the CAN bus. ib Charging gun malfunction information is synchronized to N i+1 Charging pile, N i+1 The charging station will be placed at its own N i+1a The charging gun node is in an offline state, at which time N i+1a The charging gun will not charge N i Charging pile calling module;

[0020] When the fault is recovered, N i Charging piles and N i+1 The charging pile underwent a joint self-test again, and resumed N mode after passing the self-test. ib Charging gun and N i+1a Charging gun node status.

[0021] Preferably, when n charging piles are connected, P i This represents the rated power of the i-th charging pile. After completing the joint self-test, the SECC of each connected charging pile reports its rated power to the OCPP. The sum of the reported rated powers is the maximum connected power, i.e.

[0022] Preferably, when the maximum online power exceeds the rated power of the charging gun cable, the OCPP will issue a maximum power limit including:

[0023] With P t This represents the maximum output power of the current N combined charging piles, expressed in P. ia This represents the maximum output power of the i-th charging station gun A, when P t Greater than P ia At that time, N i Charging stations will issue restrictions to the SECC through the OCPP, limiting N iaThe maximum charging power of the charging gun is P ia When N ia Plug in the charging gun to start charging. If the vehicle requests a power output greater than P... ia And N ia The output power that the charging gun can obtain through connection is also greater than P. ia By limiting the maximum power, N ia The output power of the charging gun will not exceed P ia To prevent N ia The charging gun cable melted due to overload. The power output was greater than P. ia And N ia The output power that the charging gun can obtain through connection is also greater than P. ia By limiting the maximum power, N ia The output power of the charging gun will not exceed P ia To prevent N ia The charging gun cable melted due to overload.

[0024] Preferably, when connected in a chain, a maximum of N-1 charging guns can be connected simultaneously to increase the output power; when connected in a ring, a maximum of N charging guns can be connected simultaneously to increase the output power.

[0025] The technical effects and advantages of this invention are as follows: This multi-DC charging pile adaptive connection method, when the current single-unit output power cannot meet the vehicle's needs, broadcasts a search to see if there are any idle power modules available for use in the connected piles; after the connection parameters are set, it automatically broadcasts to build a connection topology, increasing the single-unit output power; it also supports connection of any number of charging piles and switching between chain and ring topologies. Based on the chain topology, only one set of contactors and output lines needs to be added, and the connection topology can be switched to a ring structure by setting the connection topology to ring via the HMI interface or remote control; based on the ring topology, only the connection topology can be switched to chain via the HMI interface or remote control; when an abnormal state occurs at a connection node, the abnormal state can be detected immediately and the node can be removed from the connection state to avoid danger; simultaneously, when the abnormal state recovers... After recovery, the charging station can autonomously restore its online status through a joint self-test without human intervention. When the total rated power of the online connection exceeds the rated output power of the charging gun cable, the maximum output power of the charging gun cable is limited to prevent overheating and combustion. Each charging pile can be connected by adding only one set of communication cable, one set of output cable, and one set of relays. The number and structure of online connections can be freely controlled by setting online parameters through the HMI interface or remote control. Furthermore, SECC adds online self-test function and status sharing between charging piles, improving the reliability of online functions without human intervention. In cases where the online power exceeds the cable's carrying capacity, OCPP intelligently limits the maximum output capacity of the charging gun to avoid this, effectively improving charging efficiency by rationally utilizing idle power modules of the connected charging piles while ensuring charging safety and reliability. Attached Figure Description

[0026] Figure 1 This is a schematic flowchart of the method of the present invention;

[0027] Figure 2 This is a schematic diagram of the chain electrical connection of the present invention;

[0028] Figure 3 This is a schematic diagram of the ring-type electrical connection of the present invention.

[0029] In the diagram: 11, First output contactor; 12, Second output contactor; 21, Parallel contactor; 31, Combined contactor. Detailed Implementation

[0030] 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.

[0031] This invention provides, for example Figure 1 The adaptive online method for multiple DC charging piles shown in the figure includes the following definitions of terms:

[0032] EVCC stands for Electric Vehicle Communication Controller, which is used to communicate with external charging equipment (such as charging stations);

[0033] SECC stands for Supply Equipment Communication Controller, which is used for vehicle-side communication, power dispatching, etc.

[0034] OCPP stands for Open Charge Point Protocol, which is used for communication between charging piles and the back-end management system, and also communicates with SECC to achieve charging control.

[0035] The output contactors include: a first output contactor 11 and a second output contactor 12. The first output contactor 11 and the second output contactor 12 are respectively used to control the on / off connection between the power module M1 and the power module M2 and the two charging guns A and B, respectively, using K. ia_out and K ib_out express;

[0036] Parallel contactor 21 is used to control whether power modules are connected in parallel, using K i_m1m2 express;

[0037] The combined contactor 31 is used to control whether the charging piles are connected to each other, using K. i_comb express;

[0038] This embodiment describes a method for connecting three two-stage charging piles, specifically including the following steps:

[0039] S1: The SECCs of the three charging piles are connected via CAN cables to form a CAN communication network. Each charging pile contains two charging guns and four power modules. The fourth power module of the previous charging pile and the first power module of the next charging pile are connected by cables, and a contactor is added to the cables. Because it is a ring connection, the fourth power module of the last charging pile will be connected to the first power module of the first charging pile, thus completing the electrical wiring. Figure 2 As shown, when connected in a chain, a maximum of N-1 charging guns can be connected simultaneously to boost output power; for example... Figure 3 As shown, when connected in a ring, it can support up to N charging guns simultaneously to boost output power through connection.

[0040] S2: Power on all charging stations that need to be connected. After powering on, each charging station will perform its own self-test.

[0041] S21. Sequentially close the output contactor and parallel contactor 21 of the charging pile itself, and check the contactor feedback status to determine whether the contactor is working properly. When the feedback status is inconsistent with the control status, the severity of the fault will be classified according to the contactor level. When the output contactor is abnormal, the charging gun will be set to unusable. When the parallel contactor 21 is abnormal, the contactor will be set to unusable, without affecting the usability of the charging gun.

[0042] S22. Close the first output contactor 11 and all parallel contactors 21 from charging gun A to the power module, and control the power module to discharge. Read the meter voltage of charging gun A, and compare the power module voltage with the meter voltage. When the voltages match, charging gun A passes the self-test; when the voltages do not match, charging gun A fails the self-test and triggers a fault. Then disconnect all contactors. Charging gun B then repeats the above process. After the charging pile completes its self-test, the power module goes into sleep mode.

[0043] S3: The OCPP transmits the connection parameters to the SECC via the network cable, informing the SECC whether the connection function is enabled, the maximum number of connections, and the local charging pile ID; when the connection function is enabled, the SECCs of two adjacent charging piles will share their self-test status via the CAN bus; Figure 3 Taking charging pile 1 and charging pile 2 as examples, when the charging gun B of charging pile 1 passes its self-test and the charging gun A of charging pile 2 passes its self-test, step S4 is executed; otherwise, the joint self-test fails.

[0044] S4: Charging gun 1 controls its own combined contactor 31 to close and open, and reads the feedback signal of the combined contactor 31. When the feedback signal is consistent with the control state, the action detection of the combined contactor 31 passes; otherwise, the combined self-test fails. Then, charging pile 1 closes its own combined contactor 31 and sends a power module discharge command to the SECC of charging pile 2 via the CAN line, so that charging pile 2 wakes up the power module to discharge. At this time, charging pile 1 reads the meter data of charging gun B and compares it with the power module data. If the data is consistent, the combined self-test passes; otherwise, the combined self-test fails.

[0045] In one embodiment, if the charging station passes the joint self-test, the following steps are performed:

[0046] S5: The SECC of each charging pile is accumulated through a joint self-test to determine the rated power of the charging pile, and the power is reported to the central controller. The central controller then updates the maximum power on the HMI interface to the online power. When the online power exceeds the rated power of the charging gun cable, the central controller will limit the maximum output power of the charging gun to the rated power of the cable.

[0047] In one embodiment, if the charging gun B of the online charging station 2 starts charging, the following steps are performed:

[0048] The SECC of charging pile 2 establishes communication with the EVCC of the vehicle to negotiate charging parameters. When the remaining output power of charging pile 2 is greater than the power required by the EVCC, the online power module will not be called. When the remaining output power of charging pile 2 is less than the power required by the EVCC, the SECC will read the status of charging gun A of charging pile 2 and the status of charging gun B of charging pile 1. If the status of charging gun A of charging pile 2 or charging gun B of charging pile 1 is unavailable, it means that the online link from charging pile 2 to charging pile 1 is unusable. Then the SECC will read the status of charging gun A of charging pile 3. If the status of charging gun A is unavailable, it means that the online link from charging pile 2 to charging pile 3 is unusable, the online output fails, and the maximum output power of charging gun B of charging pile 2 is the remaining output power of charging pile 2. If one of the links is available, charging gun B of charging pile 2 will notify the SECC on the link of the additional power requirement according to the link until the power requirement of the vehicle is met. If both links are available, the SECC of charging pile 2 will follow the shortest path principle and prioritize calling the power module closest to charging gun B until the power required by the vehicle is met.

[0049] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for adaptive online connection of multiple charging piles, characterized in that: include: Connect to the charging station that needs to be connected online and set the connection mode; Each connected charging station performs a self-test; If the charging pile self-test is normal, then perform a joint self-test. When a charging station that has passed the joint self-test fails, a fault policy is executed. When the connected power exceeds the rated power of the charging gun cable, the maximum output power of the charging gun is limited. If the charging pile self-test is normal, the joint self-test will be performed, including: The charging pile controls the opening and closing of the joint contactor and reads the feedback signal from the joint contactor. When the feedback signal is consistent with the control state, the joint contactor detection passes; otherwise, the joint self-test fails. The charging pile closes the joint contactor and sends a discharge signal to another charging pile connected to the joint contactor via the CAN communication line. The charging pile that receives the discharge signal wakes up the power module connected to the one that sent the discharge signal to discharge. The charging pile that sends the discharge signal reads the voltage data of its own charging gun's meter and compares it with the voltage data of the power module that receives the discharge signal. If the meter voltage data and the power module voltage data are consistent, the joint self-test passes; otherwise, the joint self-test fails. The fault strategy to be executed when a charging pile fails through joint self-testing includes: the charging pile that has failed will send fault information to the charging pile connected to the charging gun according to the location of the faulty charging gun, and at the same time set the link connection status between the faulty charging gun and the charging pile connected to it to unavailable. Upon receiving the fault information, the charging pile updates its own connection topology and sets the connection status of the link between the faulty charging gun and the faulty charging gun to unavailable. Once the faulty charging station is repaired, it will send charging gun fault recovery information to the connected charging stations. The charging station that receives the charging gun fault recovery information will then perform a joint self-test. After the joint self-test passes, the link will be restored to online status.

2. The adaptive online method for multiple charging piles according to claim 1, characterized in that: The charging stations that require online connection include: Each charging station that needs to be connected online has its SECC connected via a CAN communication line; Each charging station is connected to a set of joint contactors and output cables. Configure the online parameters for any charging station and send them to the SECC of the connected charging station after completion.

3. The adaptive online method for multiple charging piles according to claim 2, characterized in that: The online parameters include: Whether to enable online functionality, online topology, maximum number of online connections, and current charging pile ID.

4. The adaptive online method for multiple charging piles according to claim 1, characterized in that: The online modes include: The ring structure includes: all charging piles participating in the connection are connected in series to form a closed-loop structure; The chain structure includes all charging piles participating in the connection being connected in series.

5. The adaptive online method for multiple charging piles according to claim 4, characterized in that: The closed-loop structure formed by connecting all the charging piles participating in the online system includes: each power module of each charging pile is connected in parallel with each other, the last power module of the first charging pile is connected to the first power module of the second charging pile, the remaining charging piles are connected in sequence, and the last power module of the last charging pile is connected to the first power module of the first charging pile.

6. The adaptive online method for multiple charging piles according to claim 1, characterized in that: The online charging piles perform self-tests, including: sequentially closing and opening all contactors of the charging pile, detecting the feedback status of all contactors, determining whether all contactors are working properly, and when the feedback status is consistent with the control status, the contactor action detection is successful. When the feedback status is inconsistent with the control status, the fault type will be analyzed based on the contactor type.

7. The adaptive online method for multiple charging piles according to claim 6, characterized in that: When the feedback state and the control state are inconsistent, the fault type will be analyzed based on the contactor type, including: When the output contactor malfunctions, the charging gun connected to that output contactor becomes unusable. When the parallel contactor between power modules malfunctions, the state of the parallel contactor is set to unusable. Close the output contactor and parallel contactor to control the power module to discharge. Read and compare the discharge voltage of the power module and the voltage reading of the meter. If the discharge voltage of the power module and the voltage reading of the meter are consistent, the charging gun connected to the power module and the meter is discharging normally. When the discharge voltage of the power module and the voltage reading of the charging gun meter are inconsistent, the charging gun connected to the meter is set to unusable status. After the test is completed, the power module is put into hibernation and all contactors are disconnected.

8. The adaptive online method for multiple charging piles according to claim 1, characterized in that: The limitation of the maximum output power of the charging gun when the online power exceeds the rated power of the charging gun line includes: the OCPP limits the maximum output power of the charging gun according to the rated power of the charging gun line and sends the limit value to the SECC. When the EVCC at the vehicle end requests power greater than the rated power of the charging gun line, it outputs according to the maximum output power limit value of the charging gun.

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