Patent Description:
Recently, the demand for eco-friendly electric vehicles (EVs) has been increased depending on the trend of reinforcement of global environmental regulations and energy cost reduction. As automotive fuel economy and exhaust gas regulations of governments around the world are strengthened, the spread of EVs has been required, and even in Korea, as part of low-carbon green growth, interest and research on green cars (eco-friendly vehicles) have been actively conducted.

In order to expand the spread of electric vehicles (EVs), it is required to establish a charging infrastructure capable of charging the power of the electric vehicles. In particular, increasing the battery capacity of the electric vehicles has a disadvantage of increasing the weight of the vehicle body, and as a result, an operable distance of the EV by once full-charging may be limited. Accordingly, in addition to household charging facilities, many chargers need to be essentially installed so as to charge electric vehicles anytime everywhere during medium- and long-distance driving.

<CIT> discloses a method, a charge controller, a charger and charging system for charging a battery of an electric vehicle. In the document the method is described to include determining a priority for each port where an electric vehicle is connected, assigning a maximum available power budget to a port with first priority, performing a charge session at the port with the first priority, monitoring actual power delivered to the vehicle from the priority port, adjusting the power budget value of the priority port depending on the actual power delivered to the vehicle and assigning a remaining portion of the power budget to the port with the second highest priority, if the power budget exceeds a predetermined threshold value, and starting or restarting a charge session at the port where the remaining portion of the power budget is assigned.

However, in the case of conventional chargers, since only one charging module is used, there is a problem that the maximum efficiency is not usable for charging the electric vehicle, and as a result, the power waste occurs.

For example, when a maximum output level of one charging module provided in the charger is <NUM> V and <NUM> A, the charging output amount needs to be gradually reduced as the electric vehicle is gradually charged. Eventually, since the maximum output level of the charger is not fully used, the charge efficiency is not only reduced, but also the power waste will occur.

An object of the present disclosure is to solve a power waste problem which may occur by using one charging module.

According to an exemplary embodiment of the present disclosure, it is possible to increase the charge efficiency and reduce the power waste by using the maximum output level of each charging module as much as possible.

Further, according to an exemplary embodiment of the present disclosure, since a power sharing operation is enabled using a plurality of charging modules, it is possible to simultaneously charge a plurality of electric vehicles.

Further, according to an exemplary embodiment of the present disclosure, it is possible to prevent an inrush current.

The present disclosure to be described below may have various modifications and various exemplary embodiments, and specific exemplary embodiments will be illustrated in the drawings and described in detail. However, the present disclosure to be described below is not limited to specific exemplary embodiments.

Terms such as first, second, A, B, and the like may be used for describing various components, but the components are not limited by the terms and the terms are used only for distinguishing one component from other components. For example, a first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component, without departing from the scope of the invention to be described below. A term 'and/or' includes a combination of a plurality of associated disclosed items or any item of the plurality of associated disclosed items.

It is to be understood that singular expressions encompass plural expressions unless otherwise indicated in the context, and it should be understood that the term "including" or the like indicates that a feature, a number, a step, an operation, a component, a part or the combination thereof described herein is present, but does not exclude a possibility of presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

Before the detailed description of the drawings, the distinction to components herein is to clarify that each component is only distinguished for each main function of each component. That is, two or more components to be described below may be combined into one component or one component may be divided into two or more components for each subdivided function. In addition, each of the components to be described below may additionally perform some or all of the functions that are handled by other components in addition to main functions that the corresponding component is responsible for, and some of the main functions of which the respective components are charged may be exclusively carried out by other components.

Further, in performing methods or operating methods, respective processes of configuring the method may be performed differently from a specified order unless otherwise disclose a specific order in the context. That is, the respective processes may be performed similarly to the specified order, performed substantially simultaneously, and performed in an opposite order.

<FIG> is a diagram illustrating a charger according to an exemplary embodiment of the present disclosure.

Referring to <FIG>, a charger <NUM> proposed herein includes a plurality of charging modules <NUM>-<NUM> to <NUM>-N.

As described above, since a conventional charger used only one module, as an electric vehicle is gradually charged, the output power (especially, a current) is reduced, and as a result, there is a problem that the charge efficiency is lowered and the power waste is severe. In order to solve this problem, the present disclosure provides the charger <NUM> for performing charging by using the plurality of charging modules <NUM>-<NUM> to <NUM>-N.

When the charging of an electric vehicle <NUM> is completed by a predetermined ratio when using the plurality of charging modules <NUM>-<NUM> to <NUM>-N, the charger <NUM> may deactivate the charging module <NUM> one by one and charge the electric vehicle <NUM> by maximally using the maximum output power of the remaining activated charging modules <NUM>. As a result, since each charging module <NUM> may be charged while exhibiting the maximum charge efficiency, the overall charging efficiency is improved and the power waste is reduced.

The plurality of charging modules <NUM>-<NUM> to <NUM>-N may be easily used for a power sharing operation. For example, when charging the electric vehicle <NUM>, each charging module <NUM> may operate independently of other charging modules <NUM>. Thus, the charger <NUM> may perform the charging by using/activating all the charging modules <NUM>-<NUM> to <NUM>-N or using/activating only one charging module <NUM> to use one electric vehicle <NUM>. The charging modules <NUM> that are not used for charging may be used to charge other electric vehicles <NUM>, which eventually corresponds to the power sharing operation.

The plurality of charging modules <NUM>-<NUM> to <NUM>-N may be the same as or different from each other in the maximum output current (or power) level. In this specification, for convenience of description, it is assumed that all of the plurality of charging modules <NUM>-<NUM> to <NUM>-N in the charger <NUM> have the same maximum output current level.

Basically, the charger <NUM> of the present disclosure first allocates the charging module to be used for charging to an electric vehicle <NUM>-<NUM> on which charging is first reserved (or charging is requested) and allocates the charging modules by comprehensively considering a requested charging amount of the corresponding electric vehicles <NUM>-<NUM> to <NUM>-N, the number of charging modules <NUM> to be currently allocated (i.e., charging modules during deactivating/unusing), and the like with respect to lower-priority electric vehicles <NUM>-<NUM> to <NUM>-N. Hereinafter, for convenience of description, an electric vehicle which is charging by the current charger <NUM> using at least one charging module is referred to as a 'first electric vehicle to be charged <NUM>-<NUM>' and lower-priority electric vehicles to be charged <NUM>-<NUM> to <NUM>-N are referred to as a 'second electric vehicle to be charged'.

Furthermore, the charger <NUM> of the present disclosure first determines a charging mode of the electric vehicle <NUM> requesting the charging and performs the charging based on the corresponding charging mode, and the charging mode will be described below with reference to <FIG>.

<FIG> is a diagram illustrating a charging mode according to an exemplary embodiment of the present disclosure.

Referring to <FIG>, the charger may charge the electric vehicle in an increase mode <NUM> or a decrease mode <NUM>.

The increase mode <NUM> corresponds to a mode of charging the first electric vehicle to be charged by selectively activating at least one charging module while being deactivated among the plurality of charging modules. The decrease mode <NUM> corresponds to a mode of selectively deactivating at least one of the charging modules activated to charge the first electric vehicle to be charged. A specific exemplary embodiment of each mode will be described below in detail with reference to <FIG>.

The charger determines in real time which mode is to be applied according to a charging request current level and a charging state (e.g., the number of charging modules to be used for current charging, and the like) of the electric vehicle to be charged and performs the charging operation according to a determined mode.

<FIG> is a flowchart illustrating a charging method of a charger according to an exemplary embodiment of the present disclosure. <FIG> is a flowchart illustrating a charging method in an increase mode of the charger according to an exemplary embodiment of the present disclosure. <FIG> is a flowchart illustrating a charging method in a decrease mode of the charger according to an exemplary embodiment of the present disclosure.

First, referring to <FIG>, first, the charger may receive first information on the charging current level requested by the first electric vehicle to be charged from the first electric vehicle to be charged (S310). To this end, the charger may use various communication protocols according to the standard of the electric vehicle to be charged.

For example, when the first electric vehicle to be charged satisfies a direct current (DC) combo standard, the first electric vehicle to be charged may transmit `EVTargetCurrent' corresponding to request current information included in a message 'CurrentDemand' to the charger using a programmable logic controller (PLC) communication protocol. Alternatively, when the first electric vehicle to be charged satisfies a CHAdeMO standard, the first electric vehicle to be charged may transmit a request current value included in `CAN ID 0x102' to the charger using a controller area network (CAN) communication protocol. Alternatively, when the first electric vehicle to be charged satisfies a GB/T standard, the first electric vehicle to be charged may transmit a request current value included in a message `CAN ID BLC' to the charger using a CAN communication protocol.

Next, the charger may determine a charging mode of the first electric vehicle to be charged based on the first information (S310).

More specifically, when the charging current level requested by the first electric vehicle to be charged is larger than the sum of maximum output currents of the charging module while being currently connected to the first electric vehicle to be charged, the charger may determine a charging mode of the first electric vehicle to be charged as an increase mode.

For example, as illustrated in <FIG>, it may be assumed that a charger <NUM> includes four charging modules <NUM>-<NUM> to <NUM>-<NUM> having output current levels and a first electric vehicle to be charged <NUM> receives a charging current level of <NUM> A through two charging modules <NUM>-<NUM> and <NUM>-<NUM> from the current charger <NUM>. At this time, the level of the current requested by the first electric vehicle to be charged <NUM> may be increased to <NUM> A by various causes (e.g., a case where the user inputs an increase command of a vehicle charging rate/amount, etc.). In this case, the charger <NUM> may determine the charging mode of the first electric vehicle to be charged <NUM> as the increase mode.

In addition, when the charging current level requested by the first electric vehicle to be charged is smaller than the sum of maximum output currents of the charging module while being currently connected to the first electric vehicle to be charged, the charger may determine a charging mode of the first electric vehicle to be charged as a decrease mode.

For example, as illustrated in <FIG>, it may be assumed that a charger <NUM> includes four charging modules <NUM>-<NUM> to <NUM>-<NUM> having output current levels of <NUM> A and a first electric vehicle to be charged <NUM> receives a charging current level of 200A through the four charging modules <NUM>-<NUM> and <NUM>-<NUM> from the current charger. At this time, the level of the current requested by the first electric vehicle to be charged <NUM> may be decreased to <NUM> A by various causes (e.g., a case where the battery charging is completed by a predetermined ratio, etc.). In this case, a charger <NUM> may determine the charging mode of the first electric vehicle to be charged <NUM> as the decrease mode.

Next, the charger may charge the first electric vehicle to be charged in the charging mode determined in the previous step (S330).

More specifically, when the increase mode is applied, the charger may selectively activate the charging modules by the number of rounding up a result obtained by dividing the charging current level requested by the first electric vehicle to be charged by the maximum output current and charge the first electric vehicle to be charged using the activated charging modules.

For example, referring to <FIG>, since the charging current level requested by the first electric vehicle to be charged <NUM> is <NUM> A and the maximum output current level is <NUM> A, four (= <NUM> A/<NUM> A) charging modules <NUM>-<NUM> to <NUM>-<NUM> need to be activated. Since only two charging modules <NUM>-<NUM> and <NUM>-<NUM> are currently activated to charge the first electric vehicle to be charged <NUM>, the charger <NUM> is used to charge the first electric vehicle to be charged <NUM> by selectively activating two <NUM>-<NUM> and <NUM>-<NUM> of the charging modules to be currently deactivated. Accordingly, in the increase mode, the maximum number of charging modules to be selectively activated is limited to the number of charging modules which are currently being deactivated.

Similarly, when the decrease mode is applied, the charger may selectively deactivate charging modules as large as a number obtained by rounding up a result obtained by dividing the charging current level requested by the first electric vehicle to be charged by the maximum output current from the number of charging modules activated for charging of the first electric vehicle to be charged.

For example, referring to <FIG>, since the charging current level currently provided to the first electric vehicle to be charged <NUM> is <NUM> A, the requested charging current level is <NUM> A, and the maximum output current level is <NUM> A, two charging modules as a result obtained by subtracting <NUM> (= <NUM> A/<NUM> A) from <NUM> (<NUM> A/<NUM> A) need to be deactivated. Since four charging modules <NUM>-<NUM> to <NUM>-<NUM> are currently activated to charge the first electric vehicle to be charged <NUM>, the charger <NUM> charges the first electric vehicle to be charged <NUM> by selectively deactivating two <NUM>-<NUM> and <NUM>-<NUM> of the four charging modules <NUM>-<NUM> to <NUM>-<NUM> activated. Accordingly, in the decrease mode, the maximum number of charging modules to be selectively deactivated is limited to the number of charging modules which are being currently activated to charge the first electric vehicle to be charged.

The charger converts an activated/deactivated state of the charging modules according to the charging mode of the electric vehicle to be charged, and at this time, the charger may perform activation/deactivation of the charging modules selectively based on an activated number and/or an activating cycle of each charging module.

More specifically, the charger may first store second information on an activated number and/or an activating cycle of each of the plurality of charging modules. Based on the second information stored above, the charger may first select and activate a charging module activated at the least number and/or the rarest cycle of the plurality of charging modules when applying the increase mode. Further, the charger may first select and deactivate a charging module activated at the most number and/or the most frequent cycle among the plurality of charging modules when applying the decrease mode.

As such, since the charger performs the activation/deactivation operation selectively by considering the activation cycle/frequency of each charging module, it is possible to prevent the intensive deterioration of some charging modules and equally manage the overall lifetime of the charging modules.

<FIG> is a diagram illustrating a power sharing operation according to an exemplary embodiment of the present disclosure.

As described above, a charger <NUM> of the present disclosure includes a plurality of charging modules, and since each of these charging modules enables an independent charging operation, the charger <NUM> may perform a power sharing function capable of simultaneously charging a plurality of electric vehicles <NUM>-<NUM> and <NUM>-<NUM> once. Accordingly, as the charging of a first electric vehicle to be charged <NUM>-<NUM> is completed, the sequentially deactivated charging module may be used to charge a second electric vehicle to be charged <NUM>-<NUM> which is a lower-priority charging target.

For example, referring to <FIG>, when a charging current level currently received by the first electric vehicle to be charged <NUM>-<NUM> is <NUM> A and a request current is <NUM> A, a decrease mode may be applied, and as a result, two <NUM> A charging modules may be deactivated. The two charging modules deactivated as such may be used for charging the lower-priority electric vehicle to be charged <NUM>-<NUM>. In <FIG>, since the current requested by the second electric vehicle to be charged <NUM>-<NUM> is <NUM> A, all of two charging modules may be used to charge the second electric vehicle to be charged <NUM>-<NUM>. When the request current of the second electric vehicle to be charged <NUM>-<NUM> is <NUM> A, only one charging module may be activated for the second electric vehicle to be charged <NUM>-<NUM>, and the remaining charging modules may be used for charging the next lower-priority electric vehicle to be charged.

<FIG> is a graph showing a current detected from the charger when an inrush current occurs according to an exemplary embodiment of the present disclosure.

While the charger activates/deactivates the charging module, as illustrated in <FIG>, an inrush current as a high level of current may be suddenly introduced. The inrush current is a very higher level of current than a reference charging current, and safety and maintenance problems are caused in the charging process of the electric vehicle. Particularly, in an electric vehicle charger for supplying a three-phase alternating current to the electric vehicle, an unnecessary operation of a circuit breaker and unnecessary tripping of an earth leakage breaker are caused in the charger due to the inrush current. Therefore, it is very important to prevent the inrush current in activating/deactivating the charging module.

The present disclosure provides an operation of a charger for preventing the inrush current, and will be described below with reference to <FIG> and <FIG>.

<FIG> is a graph showing an inrush current prevention operation when applying a decrease mode of the charger according to the invention.

Referring to <FIG>, the charger may first reduce a currently charging current level to a predetermined ratio A0 when applying the decrease mode to prevent the inrush current. According to the invention, the predetermined ratio corresponds to <NUM>% of the currently charging current level.

Next, the charger checks whether the inrush current occurs for a predetermined time t0. If it is checked that the inrush current does not occur for the predetermined time t0, the charger may deactivate the charging module which was intended to be deactivated. As a result, a maximum chargeable current of the charger is reduced by a maximum chargeable current of the deactivated charging module.

Next, the charger checks whether the inrush current occurs according to the deactivation of the charging module again for a predetermined time t1. If it is checked that the inrush current does not occur for the predetermined time t1, the charger increases a charging current level by a charging current level requested by the first electric vehicle to be charged to return to an original charging operation/algorithm.

<FIG> is a graph showing an inrush current prevention operation when applying an increase mode of the charger according to the invention.

Referring to <FIG>, the charger may first reduce a currently charging current level to a predetermined ratio A0 when applying the increase mode to prevent an inrush current. According to the invention, the predetermined ratio corresponds to <NUM>% of the currently charging current level.

Next, the charger checks whether the inrush current occurs for a predetermined time t0. If it is checked that the inrush current does not occur for the predetermined time t0, the charger may activate the charging module which was intended to be activated. As a result, a maximum chargeable current of the charger is increased by a maximum chargeable current of the activated charging module.

Next, the charger checks whether the inrush current occurs according to the activation of the charging module again for a predetermined time <NUM>. If it is checked that the inrush current does not occur for the predetermined time t1, the charger increases a charging current level by a charging current level requested by the first electric vehicle to be charged to return to an original charging operation/algorithm.

According to the exemplary embodiment of <FIG> and <FIG> described above, the charger of the present disclosure has advantages of lowering the charging current level by a predetermined ratio before activating or deactivating the charging module to prevent the inrush current in advance and continuously detecting the inrush current before and after activating/deactivating to minimize the damage according to the occurrence of the inrush current.

<FIG> is a block diagram illustrating a charger according to an exemplary embodiment of the present disclosure.

Hereinafter, configurations to be described below may be implemented by at least one hardware/software components and may be used to perform the exemplary embodiments described above.

Referring to <FIG>, the charger may include a control unit <NUM>, a charging unit <NUM>, a sensor unit <NUM>, a communication unit <NUM>, and/or a memory unit <NUM>.

The control unit <NUM> may not only communicate with other components included in the charger, but also may control the components. In particular, the control unit <NUM> may subjectively perform various exemplary embodiments described in the present disclosure by controlling at least one component included in the charger. Accordingly, the charger of the present disclosure may be described to be identified with the control unit <NUM>. The control unit <NUM> may be implemented by at least one processor.

The charging unit <NUM> may include a hardware component necessary for charging the electric vehicle. For example, the charging unit <NUM> may include a plurality of charging modules and a charging connection unit for connecting the electric vehicle and the charger to supply power.

The sensor unit <NUM> senses a peripheral environment inside/outside the charger and may transmit a sensing result to the control unit. For example, the sensor unit <NUM> may include at least one current/voltage detection sensor, and may monitor an internal current/voltage in real time to notify the result to the control unit. In particular, the sensor unit <NUM> may sense the inrush current before and after activation/deactivation of the charging module and transmit the result to the control unit <NUM>.

The communication unit <NUM> may perform communication with the outside using at least one communication protocol. In particular, the communication unit <NUM> may perform the communication using PLC, CAN, WiFi, Bluetooth, and NFC, as at least one communication protocol. The communication unit <NUM> may transmit a signal/information/data transmitted and received through communication to the control unit and may transmit the signal/information/data received from the control unit <NUM> to the outside.

The memory unit <NUM> may store various information/data/programs/applications, and the like. The memory unit <NUM> may transmit the stored information/data to the control unit or receive the stored information/data from the control unit <NUM>. Particularly, the memory unit <NUM> according to the present disclosure may store information/data on frequency/number/period, and the like at which each charging module is activated (or deactivated).

Meanwhile, for convenience of description, in the present disclosure, in <FIG> and <FIG>, etc., an exemplary embodiment in which a plurality of connection terminals is provided in one charger and one charger is connected with a plurality of electric vehicles through the plurality of connection terminals has been illustrated, but is not limited thereto. Of course, a plurality of dispensers is provided in one charger and the charger may also be connected with the plurality of electric vehicles through the plurality of dispensers.

Although the drawings have been described for the sake of convenience of explanation, it is also possible to design a new exemplary embodiment to be implemented by merging the exemplary embodiments described in each drawing. Further, configurations and methods of the described exemplary embodiments may not be limitedly applied to the aforementioned present disclosure, but all or some of the respective exemplary embodiments may be selectively combined and configured so as to be variously modified.

Claim 1:
A method for preventing an inrush current of an electric vehicle charger having a charging unit including a plurality of charging modules comprising steps of:
determining whether there is a need for an increase or decrease in a charging current level while currently supplied to an electric vehicle to be charged according to a request of the electric vehicle to be charged;
decreasing the charging current level at a predetermined ratio when it is determined that there is the need for the increase or decrease in the charging current level, wherein the predetermined ratio corresponds to <NUM>% of the charging current level;
checking whether an inrush current occurs during a first time interval (to);
activating or deactivating at least one charging module of the plurality of charging modules to increase or decrease the charging current level according to the request of the electric vehicle to be charged, when the inrush current does not occur during the first time interval (to);
checking whether the inrush current occurs during a second time interval (t<NUM>); and
increasing the charging current level by the charging current level requested by the electric vehicle to be charged, when the inrush current does not occur during the second time interval (t<NUM>).