Charging process control of a power electronics system

Abstract

Method for a charging process control of power electronics, in which a charging power is provided by the power electronics, in which a charging unit operated by a user, which transmits the charging power to a battery, is controlled by a charging controller, in which a communication exchange is carried out at least between a control unit of the power electronics and the charging controller, in which several charging process states are predetermined, in which processes between the charging process states are stored in a program flow chart and in which the program flow chart is used for a charging process control of the power electronics, wherein the program flow chart ensures compatibility with at least one predetermined charging standard, wherein starting from a switch-on process, the charging process states "initialization" (10), "ready to charge" (1), "initialization of the charging interface" (2), "insulation measurement" (3), "pre-charging" (4),"Charge" (5), "End charging" (6), "Charge completed" (7), and in the event of an error, the charging process states "Not ready to charge" (8) and "Charge error" (9) are predetermined, wherein the respective charging process state is assigned at least one respective task and / or is formed by at least one respective piece of status information coupled to the respective charging process state, wherein the communication exchange with the charging control is formed by at least one of the status information, wherein, if no error occurs, a change is made to the next charging process state as soon as a respective task is completed and / or a change is triggered by a communication exchange with the charging control, and wherein, if an error occurs, a change is made to the charging process states "Charge error" or "Not ready to charge" (8) and, after the error has been rectified, a change is made to the charging process state "Ready to charge" (1).

Description

[0001] The present invention relates to a method for controlling the charging process of power electronics, which relates to the charging of electric vehicles in a charging park. Furthermore, a system is claimed that includes the charging process control of the power electronics.

[0002] Charging parks are designed for charging or rapid charging an electric vehicle with high direct voltages or currents. These can comprise multiple charging units, such as charging columns or charging stations, and several components, such as a cooling unit, also known as a cooling box, and / or power electronics that generate the high direct voltages or currents. These can be designed either as a standalone module (also known as a LEM) with a power electronics control unit, or integrated into a so-called charge box (also known as a CBX) with a charge box controller as the control unit. For most charging parks installed today, it must be assumed that the various components are limited to the charging columns or charging stations.This spatial unit within a charging station allows the components to be managed by a single main control unit, but communication between multiple components in a charging station is also conceivable. The latter is described in the document DE 10 2011 113 355 A1, in which status information from the charging station's components is exchanged with a central computer.

[0003] If, however, the components are spatially distributed, communication between the respective components or their control units becomes unavoidable. This may also require communication between a respective charging station and a central administration, for example, regarding the charging power to be provided. In this regard, the document DE 10 2009 036 816 A1 discloses a method and a device for controlling charging stations for electric vehicles, which is intended to minimize peak load requirements caused by multiple electric vehicles charging simultaneously. Preferably, several charging stations are combined into a group, and the charging power to be provided for each group is estimated through communication with the respective groups using a central computer.

[0004] The charging stations in use around the world are equipped with various components that communicate with each other, and the communication must be coordinated accordingly. Furthermore, the components must implement the charging processes externally in compliance with standards. For this purpose, the industry standards DIN EN 61851-1 and DIN SPEC 70121 describe the charging process in considerable detail at a powerline communication level, also known as PLC. However, it is conceivable to agree on a simpler communication between the individual components.

[0005] DE 10 2017 124 054 A1 discloses a system for a vehicle including an interpack switch configured to connect sections of a traction battery when closed to transfer electrical charge therebetween, and a controller configured to actuate the switch in response to a request to disconnect the sections and initiate a transfer of electrical charge to each of the sections in parallel and simultaneously.

[0006] DE 10 2012 204 675 A1 discloses systems and methods for initiating a charging system.

[0007] US 2015 / 0 042 277 A1 discloses a charging system for an electric vehicle and an electric vehicle comprising the same.

[0008] Against this background, it is an object of the present invention to provide a method that ensures simple communication with spatially distributed components, in particular with power electronics located outside the charging unit. To this end, meaningful states are to be developed that enable clear and secure passage through a charging process. The programming effort for a corresponding charging process control should be designed as simply as possible so that the charging process results in a simple process protocol that contains all essential features. In addition, the charging process should take all different charging standards into account. Furthermore, it is an object of the present invention to provide appropriately designed power electronics.

[0009] To achieve the above-mentioned object, a method for controlling the charging process of power electronics is proposed, in which a charging power is provided by the power electronics, in which a charging unit operated by a user, which transmits the charging power to a battery, is controlled by a charging controller or a charging control device, in which a communication exchange is carried out at least between a control device of the power electronics and the charging controller, in which several charging process states are predetermined, in which processes between the charging process states are stored in a program flow chart, and in which the program flow chart is used to control the charging process of the power electronics, wherein the program flow chart ensures compatibility with at least one predetermined charging standard, wherein, starting from a switch-on process, the charging process states "initialization","Ready to charge", "Initialization of charging interface", "Insulation measurement", "Pre-charging", "Charging", "End charging process", "Charging process completed", and in the event of an error, the charging process states "Not ready to charge" and "Charging process error" are predetermined, wherein the respective charging process state is assigned to or coupled with at least one respective task and / or is formed by at least one respective state information, wherein the communication exchange with the charging control is formed by at least one of the state information, wherein, if no error occurs, a change is made to the next charging process state, if necessary after a delay time, as soon as a respective task is completed and / or a change is triggered by communication exchange with the charging control, and wherein, if an error occurs,changes to the charging process states “Charging error” or “Not ready to charge” and changes to the charging process state “Ready to charge” after the error has been rectified.

[0010] In one embodiment of the method according to the invention, the control unit of the power electronics is formed by a power electronics control unit. The power electronics, including the power electronics control unit, can form a separate module within a charging station, referred to by those skilled in the art as an LEM.

[0011] In another embodiment of the method according to the invention, the control unit of the power electronics is formed by a ChargeBoxController. A ChargeBox comprises, among other things, the power electronics for providing the charging power and the ChargeBoxController as the control unit.

[0012] In one embodiment of the method according to the invention, the power electronics, including the control unit, and the charging controller are arranged spatially separately. If necessary, the power electronics, which generates heat during operation, are provided with a cooling unit and arranged at an appropriate distance from the charging unit housing the charging controller, so as not to disturb a user of the charging unit due to the noise generated by the cooling unit.

[0013] In the context of the present disclosure, communication exchange means a transmission of respective messages or signals between the power electronics or the control unit of the power electronics and another component and / or a control unit of the charging park or electric vehicle, in particular the charging control or the charging control unit.

[0014] In yet another embodiment of the method according to the invention, the communication exchange is carried out via Ethernet and / or power line communication and / or WLAN and / or LAN and / or CAN bus and / or mobile radio. The aforementioned means of communication are intended to represent only an exemplary selection and do not limit other possible forms of communication exchange. For example, it is conceivable that the communication exchange between the charging controller and the power electronics takes place via a permanently installed transmission cable, e.g., Ethernet within a LAN, but communication with an electric vehicle to be charged takes place via mobile radio.

[0015] The following describes a possible program flow chart for a charging process control on a power electronics control unit. The power electronics control unit communicates with at least the charging controller. By way of example, the power electronics control unit is used as the power electronics control unit, and the program flow chart is therefore described using a power electronics module, referred to as an LEM as mentioned above. In the same way, the program flow chart is also conceivable with the ChargeBoxController of a Chargebox instead of the power electronics control unit of an LEM. The transition through the charging process states occurs in such a way that the respective charging process state is assigned or coupled to at least one task, e.g. with the task of initialization, and / or forms status information, e.g."I (the respective addressed component) am ready to charge" or, with reference to the previous task, "I (the respective addressed component) have finished initializing." If the status information has been generated, a communication exchange with the charging controller takes place. Except in the event of an error or if the charging process is aborted, e.g., by the user of the charging unit, the system will only switch to the next charging process state specified in the program flow chart if requested by the charging controller through a communication exchange with the charging controller.

[0016] The program flowchart begins with the LEM switched off and is executed when it is switched on, e.g., by a user action. It then initially has the "Initialization" charging process state. If an error occurs, the charging process state changes to "Not Ready to Charge." The error could be caused, for example, by incomplete initialization, another internal system error occurring in the LEM, or an external system error communicated to the LEM, e.g., from the charging unit. If no error occurs, the "Initialization" charging process state is considered complete. This may also require communication with the charging unit's charging control, which has confirmed or specified the "Initialization" charging process state.

[0017] After the "Initialization" charging process state has been completed without errors, the program flowchart advances to the "Ready to Charge" charging process state. If an error occurs, which can be of an internal or external nature, the system switches to the "Not Ready to Charge" charging process state. As soon as the system determines that charging is ready, possibly after exchanging communication with the charging controller, the system then enters the "Ready to Charge" charging process state. If no error occurs and the "Ready to Charge" charging process state is confirmed by the charging controller, which detects a connection between an electric vehicle and a charging plug on the charging unit, and then confirms it through a communication exchange, the program flowchart advances to the next charging process state, "Initializing the Charging Interface."

[0018] In the "Charging Interface Initialization" charging process state, the charging controller communicates with the LEM to select a predefined charging system and set of charging parameters for the electric vehicle. If the charging connector is disconnected from the electric vehicle during this time, the system returns to the previous "Ready to Charge" charging process state. If an error is detected elsewhere, the system switches to the "Charging Error" charging process state. However, if no error occurs and the charging controller requests an insulation measurement of the power electronics through communication, the "Insulation Measurement" charging process state results. Furthermore, the system can switch from the "Charging Interface Initialization" charging process state to the "End Charging Process" charging process state if the charging process is terminated prematurely, e.g., by the user aborting the process at the charging station.

[0019] When switching to the "Insulation Measurement" charging state, the LEM requests an insulation measurement of the power electronics and, depending on the charging standard, also an insulation measurement of the charging cable, and waits for the result of this insulation measurement. If an error occurs during the insulation measurement, the charging state switches to the "Charging Error" charging state. If no error occurs and the LEM sends a positive result, the next charging state, "Pre-charging," follows, provided this is also requested by the charging controller. Furthermore, the charging state can also be switched from the "Insulation Measurement" charging state to the "End Charging" charging state if the charging process is terminated prematurely.

[0020] In the "Pre-charging" charging state, a charging cable, the power electronics, and any capacitors located on the electric vehicle side are pre-charged. If an error occurs, the charging process switches to the "Charging Error" charging process state. However, if pre-charging is completed and the charging parameters specified by the electric vehicle are confirmed by the LEM, e.g., by setting a charging voltage, the next charging process state, "Charging," follows, provided its start is also requested by the charging controller. Furthermore, the charging process can also switch from the "Pre-charging" charging process state to the "End Charging Process" charging process state if the charging process is terminated prematurely.

[0021] In the "Charge" charging state, an electric vehicle battery is charged with a charging power corresponding to the charging system selection. The electric vehicle's charging parameters are continuously exchanged through communication between the electric vehicle, charging controller, and LEM. If an error occurs, the charging state switches to the "Charge Error" charging state. However, if no error occurs, the battery is charged to full charge and, upon request from the charging controller to end the charging process, switches to the "End Charging" charging state, or switches to this state anyway if the charging process is terminated prematurely.

[0022] In the "End charging" charging state, the LEM ensures that the system is free of current and voltage at one of the power electronics outputs and opens all DC contactors. If an error occurs, the system switches to the "Charging Error" charging state. If no error occurs and the LEM confirms that the system is free of current and voltage, and the DC contactors are open, the system switches to the "Charging Complete" charging state.

[0023] The charging process state "Charging completed" is an additional safety state in which the absence of current and voltage, as well as the opening of the DC contactors, must be confirmed again. This ensures that a charging plug ultimately connected to the LEM is definitely disconnected when it is removed from the electric vehicle. In this charging process state, it is possible to detect sticking or welding of the vehicle's contactors. For this purpose, a voltage measurement is carried out in front of the open contactors in the direction of the charging station and the result is transmitted to the electric vehicle via the charging control. If an error occurs, the charging process state changes to the "Charging error" charging process state. If no error occurs and the current and voltage have been established, the charging process state changes to the "Ready to charge" charging process state as soon as this is requested by the charging control.

[0024] The "Charging Error" charging process state is reached when an error occurs from the respective charging process states "Charging Interface Initialization," "Insulation Measurement," "Pre-Charging," "Charging," "End Charging," and "Charging Completed." If the error can be corrected and no longer exists, or if the electric vehicle is no longer connected to the charging unit, the charging process state changes to "Ready to Charge." If the error cannot be corrected, the charging process state changes to "Not Ready to Charge."

[0025] Finally, the charging state “Not Ready to Charge” can only be changed to the charging state “Ready to Charge” if, for example, readiness for charging has been restored by correcting the error.

[0026] In one embodiment of the method according to the invention a fast charging process is carried out, the high charging power of which is provided either by a high DC voltage and / or a high DC current.

[0027] Furthermore, a system for controlling the charging process of power electronics is claimed, which system has the power electronics, a control unit for the power electronics, and a charging unit that includes a charging controller. The system is designed to carry out an embodiment of the method according to the invention for charging a battery of an electric vehicle that is to be connected to the charging unit. Several systems according to the invention can form a so-called charging park. Dividing the system according to the invention into individual components, which may be spatially distributed, is advantageous because this allows, for example, a narrow charging station with only minimal obstruction to visibility in road traffic to be used as the charging unit.

[0028] In an embodiment of the system according to the invention, the system additionally comprises a power electronics control unit. The power electronics control unit and the power electronics can form a separate module within a charging station, referred to by those skilled in the art as an LEM, and can be located remotely from the charging station to be operated by the user.

[0029] In another embodiment of the system according to the invention, the system additionally includes a ChargeBox controller. The ChargeBox controller controls, among other things, the power electronics within a ChargeBox. With the ChargeBox, the charging station can also be installed up to 100 meters away and thus brought closer to parked vehicles.

[0030] The system is designed with the program flow chart according to the invention to ensure compatibility with charging standards known to those skilled in the art, such as ChaDeMo, GB / T or CCS.

[0031] Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawings.

[0032] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

[0033] Fig. 1 shows a program flow chart corresponding to an embodiment of the method according to the invention.

[0034] In Fig.1 shows a program flow chart 100 corresponding to an embodiment of the method according to the invention. A power electronics control unit is selected as the control unit of the power electronics system that communicates with a charging controller. The same program flow would, however, also be conceivable with a ChargeBoxController. Furthermore, in the embodiment of the method according to the invention shown, the charging controller can communicate with a charging plug control unit, which controls a charging plug that is located at the end of a charging cable connected to a charging unit and is plugged into a corresponding charging socket on the electric vehicle during a charging process of a battery included in an electric vehicle. The power electronics and power electronics control unit are arranged in a power electronics module, abbreviated LEM. The program flow chart 100 begins with the LEM switched off 110 and continues with switching on 111, which, for example,triggered by a specific action of a user, such as by plugging the charging plug into a charging socket of an electric vehicle to be charged, by removing the charging plug from the charging station, or by touching a charging station display, into a charging process state "Initialization" 10, in which an initialization 11 takes place. If an error occurs, which may be due, for example, to incomplete initialization, another internal system error occurring in the LEM, or an external system error communicated to the LEM, a change 108 to a charging process state "Not Ready to Charge" 8 is carried out. If no error occurs, the charging process state "Initialization" 10 is considered complete. This may also require a communication exchange with the charging control of the charging unit, which confirms or requests the charging process state "Initialization" 10.After the charging process state “Initialization” 10 has been completed without errors, the program flowchart advances to a charging process state “Ready to Charge” 1. If an error occurs in this charging process state, which can be of an internal or external nature, a change 18 to the charging process state “Not Ready to Charge” 8 occurs. As soon as a charging readiness 88 is deemed to be given there, possibly after an exchange of communication with the charging controller, a change 81 to the charging process state “Ready to Charge” 1 occurs. If no error occurs and the charging process state “Ready to Charge” 1 is confirmed by a communication exchange, possibly by the charging controller, which detects a connection between an electric vehicle and a charging plug of the charging unit, a change 12 to a charging process state “Initialization of Charging Interface” 2 occurs in the program flowchart.In the charging process state “initialization of charging interface” 2, the charging control transmits a selection from predetermined options for a charging system and charging parameters of the electric vehicle to the LEM via communication exchange 22. If the charging plug is disconnected from the electric vehicle during this time, a change 21 to the previous charging process state “ready to charge” 1 is initiated. If an error is detected elsewhere, a change 29 to the charging process state “charging process error” 9 takes place. However, if no error occurs and the charging control, possibly initiated by the electric vehicle, requests an insulation measurement 33 of the power electronics via communication exchange, a change 23 to a charging process state “insulation measurement” 3 takes place. Furthermore, the charging process state “initialization of charging interface” 2 can be reset if the charging process is terminated prematurely, e.g.If the user aborts the charging process at the charging station, a change 26 to a charging process state "End charging process" 6 can occur. If an error occurs during the insulation measurement 33, a change 39 to a charging process state "Charging process error" 9 occurs. If no error occurs and the LEM sends a positive result, a change 34 to a charging process state "Pre-charging" 4 occurs, provided that this is also requested by the charging controller through communication with the LEM; it is also possible that this was previously requested by a control unit of the electric vehicle during the charging controller. Furthermore, if the charging process is terminated prematurely, a change 36 occurs from the charging process state "Insulation measurement" 3 to the charging process state "End charging process" 6.In the "pre-charging" charging state 4, a charging cable and any capacitors located on the electric vehicle side and possibly the power electronics are pre-charged, although this may also be done by the electric vehicle itself. If an error occurs, a change 49 occurs to the "charging error" charging state 9. However, if pre-charging 44 is carried out and the charging parameters specified by the electric vehicle are confirmed by the LEM, e.g., by setting a charging voltage, a change 45 occurs to a "charging" charging state 5, provided that its start is also requested by the charging controller through a communication exchange with the LEM; here, too, this may have been previously requested by a control unit of the electric vehicle during the charging controller.Furthermore, if the charging process is terminated prematurely, a transition 46 can also occur from the "pre-charging" charging process state 4 to the "end charging process" charging process state 6. In a "charging" charging process state 5, the electric vehicle's battery is charged with a charging power corresponding to the charging system selection and the charging parameters of the electric vehicle. The charging parameters of the electric vehicle are continuously exchanged through communication exchange 55 between the electric vehicle, the charging controller, and the LEM, in particular between the electric vehicle and the charging controller and between the charging controller and the LEM. If an error occurs, a transition 59 to the "charging process error" charging process state 9 occurs.However, if no error occurs, the battery is charged to full charge and, upon request from the electric vehicle and / or the charging controller to end the charging process, a change 56 to a charging process state "End charging process" 6 occurs, or the charging process is changed to this state anyway if the charging process is ended prematurely. In the charging process state "End charging process" 6, the LEM performs an action 66 to ensure that there is no current and no voltage at an output of the power electronics and to open the associated DC contactors. If an error occurs, a change 69 to the charging process state "Charging process error" 9 occurs. If no error occurs and the LEM confirms that there is no current and no voltage, and the DC contactors are open, a change 67 to a charging process state "Charging process completed" 7 occurs.The charging process state "Charging process completed" 7 is an additional safety state 77 in which the power electronics control unit must once again confirm that there is no current and voltage, as well as that the DC contactors have opened. This ensures that the charging plug, which is ultimately connected to the LEM by electrical conduction, is always de-energized and voltage-free when it is removed from the electric vehicle. Furthermore, a check for sticking of the electric vehicle's contactors can be carried out in this charging process state. If an error occurs, a change 79 to the charging process state "Charging process error" 9 occurs. If no error occurs and there is no current and voltage, a change 71 to the charging process state "Ready to charge" 1 occurs, which can be requested by the charging control or occurs automatically.The charging process state “Charging process error” 9 is reached when an error occurs from the respective charging process states “Charging interface initialization” 2, “Insulation measurement” 3, “Pre-charging” 4, “Charging” 5, “End charging process” 6 and “Charging process completed” 7. If the error can be rectified 99 or the error no longer exists or the error was caused by the electric vehicle and the electric vehicle is no longer connected to the charging unit, a change 91 to the charging process state “Ready to charge” 1 occurs. If, however, the error cannot be rectified, a change 98 to the charging process state “Not ready to charge” 8 occurs. Finally, a change 81 from the charging process state “Not ready to charge” 8 can only occur if, for example, readiness to charge has been restored by rectifying the error 88.

Claims

[1] Method for a charging process control of power electronics, in which a charging power is provided by the power electronics, in which a charging unit operated by a user, which transmits the charging power to a battery, is controlled by a charging control, in which a communication exchange is carried out at least between a control unit of the power electronics and the charging control, in which several charging process states are predetermined, in which processes between the charging process states are stored in a program flow chart and in which the program flow chart is used for a charging process control of the power electronics, wherein the program flow chart ensures compatibility with at least one predetermined charging standard, wherein starting from a switch-on process, the charging process states "initialization" (10), "ready to charge" (1), "initialization of the charging interface" (2), "insulation measurement" (3),"Pre-charging" (4), "Charging" (5), "End charging process" (6), "Charging process completed" (7), and in the event of an error, the charging process states "Not ready to charge" (8) and "Charging process error" (9) are predetermined, wherein the respective charging process state is assigned at least one respective task and / or is formed by at least one respective state information coupled to the respective charging process state, wherein the communication exchange with the charging control is formed by at least one of the state information, wherein, if no error occurs, a change is made to the next charging process state as soon as a respective task is completed and / or a change is triggered by a communication exchange with the charging control, and wherein, if an error occurs,to the charging process states “Charging process error” or “Not ready to charge” (8) and to the charging process state “Ready to charge” (1) after the error has been rectified. [2] Method according to claim 1, wherein the control unit of the power electronics is formed by a power electronics control unit. [3] Method according to claim 1, wherein the control unit of the power electronics is formed by a ChargeBoxController. [4] Method according to one of the preceding claims, in which the power electronics including the control unit and the charging control are arranged spatially separately. [5] Method according to one of the preceding claims, in which the communication exchange is carried out by means of Ethernet and / or Powerline Communication and / or WLAN and / or LAN and / or CAN bus and / or mobile radio. [6] Method according to one of the preceding claims, in which a rapid charging process is carried out, the high charging power of which is provided either by a high DC voltage or a high DC current. [7] Method according to one of the preceding claims, in which the at least one predetermined charging standard is selected from the following list: ChaDeMo, GB / T, CCS. [8] System for a charging sequence control of power electronics, which has the power electronics, a control unit for the power electronics and a charging unit which includes a charging control, wherein the system is configured to carry out a method according to one of the preceding claims for charging a battery of an electric vehicle, with a charging sequence control on the respective control unit for the power electronics and for the charging control. [9] System according to claim 8, wherein the power electronics control unit is a power electronics control unit and is configured to carry out a method according to any one of claims 2, 4 to 7. [10] System according to claim 8, wherein the control device for the power electronics is a ChargeBoxController and is configured to carry out a method according to one of claims 3 to 7. [11] System according to one of claims 8 to 10, which additionally comprises a cooling box, a charging plug at the charging station, a charging plug control unit, and an electric vehicle equipped with the battery, and is configured to carry out a method according to one of claims 1 to 7.

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