Charging system for electric vehicle

Abstract

A charging system for an electric vehicle includes: a first switching unit, one end of which is selectively connected to first ends or second ends of a plurality of coils included in a motor; a plurality of switches, one end of each switch is connected to the other end of the first switch unit, and the other ends of the plurality of switches are mutually short-circuited to form a neutral point of the motor; and a controller configured to control a switching state of the first switching unit.

Description

Technical Field

[0001] The present disclosure relates to a charging system for an electric vehicle that enables battery recharging even when one or more inverters fail during recharging of a battery of the electric vehicle using a motor and an inverter. Background Art

[0002] As interest in the environment has increased recently, the use of environmentally friendly vehicles equipped with a motor as a driving source has increased. Such environmentally friendly vehicles are also called "electric vehicles." As representative examples of electric vehicles, there are electric vehicles (EV) and plug-in hybrid electric vehicles (PHEV).

[0003] Generally, an electric vehicle or a plug-in hybrid electric vehicle performs recharging of a battery therein by converting electric power supplied from an external charging facility into a state suitable for battery charging, and then supplies the converted electric power to the battery.

[0004] Conventional recharging facilities for fast recharging are manufactured to output a single standard voltage of 500 V. However, a recent trend in batteries used in vehicles is to be designed to have a voltage of 800 V or more to improve efficiency and increase driving range.

[0005] Meanwhile, some fast recharging facilities have a voltage standard of 1,000 V, and therefore, such fast recharging facilities can recharge an 800 V battery after reducing its voltage to a voltage suitable for the battery. On the other hand, when an 800 V battery is recharged using an external charging facility having a voltage standard of 500 V, a boost converter is required to boost the voltage supplied from the recharging facility.

[0006] In an electric vehicle equipped with a motor and an inverter, the coils of the motor and the power conversion switches of the inverter may function as a boost converter to boost the supplied voltage.

[0007] The above subject matter disclosed in this section is only used to enhance the understanding of the general background of the present disclosure. The above should not be regarded as an admission or any form of suggestion that the subject matter forms the prior art known to ordinary technicians in the field. Summary of the invention

[0008] Therefore, the present disclosure has been made in view of the above problems. An object of the present disclosure is to provide a charging system for an electric vehicle that can continuously perform recharging through another inverter even when an inverter performing a boost converter function fails during battery recharging of the electric vehicle.

[0009] The purpose of the present disclosure is not limited to the above-mentioned purpose. According to the following detailed description, a person skilled in the art should more clearly understand other purposes of the present disclosure that have not been described.

[0010] According to one aspect of the present disclosure, the above and other purposes can be achieved by providing a charging system for an electric vehicle. The charging system includes: a battery configured to receive or output DC power; and a motor having a plurality of coils corresponding to a plurality of phases, respectively. The charging system includes a first inverter having a first AC terminal connected to the first ends of the plurality of coils, respectively, and having a first DC terminal connected to the battery. The charging system includes a second inverter having a second AC terminal connected to the second ends of the plurality of coils, respectively, and having a second DC terminal connected to the battery. The charging system includes a first switching unit, one end of which is selectively connected to the first end or the second end of the plurality of coils. The charging system includes a plurality of switches, one end of each switch being connected to the other end of the first switching unit and the other end of each switch being short-circuited to each other to form a neutral point of the motor. The charging system includes a controller configured to control the switching state of the first switching unit.

[0011] When the battery is recharged using external power input through the neutral point, the controller may control a switching state of the first switching unit based on a state of the first inverter.

[0012] When the first inverter is in a normal state, the controller may control a switching state of the first switching unit so that one end of the first switching unit is connected to the second ends of the plurality of coils.

[0013] When the first inverter is in a fault state, the controller may control a switching state of the first switching unit so that one end of the first switching unit is connected to the first ends of the plurality of coils.

[0014] The fault state of the first inverter may include at least one of abnormality of a current sensing value of the first inverter or an excessively high temperature of the first inverter.

[0015] The abnormality of the current sensing value of the first inverter may be determined based on the current of each first AC terminal and the battery input current.

[0016] When the first inverter is in a fault state, the controller may control a switching state of the first switching unit after stopping driving of the first inverter.

[0017] When the first inverter is in a fault state, the controller may control a switching state of the first switching unit after starting driving of the second inverter.

[0018] The controller may control recharging of the battery based on a state of the second inverter under the condition that one end of the first switching unit is connected to the first ends of the plurality of coils.

[0019] When the second inverter is in a fault state, the controller may terminate recharging of the battery.

[0020] The charging system may further include a second switch unit having one end connected to an input terminal of external power for recharging the battery and another end selectively connected to the battery or another end of the plurality of switches.

[0021] When the other end of the second switch unit is connected to the other ends of the plurality of switches, the controller may control a switching state of the first switch unit based on a state of the first inverter.

[0022] The controller may control a switching state of the second switching unit based on a voltage command for the external power.

[0023] The controller may control a switching state of the second switching unit based on whether a voltage value according to the voltage command exceeds a predetermined voltage value set based on a voltage specification of the battery.

[0024] When the voltage value according to the voltage command exceeds a predetermined voltage value, the controller may control a switching state of the second switching unit so that the other end of the second switching unit is connected to the other ends of the plurality of switches.

[0025] When the voltage value according to the voltage command does not exceed a predetermined voltage value, the controller may control a switching state of the second switching unit so that the other end of the second switching unit is connected to the battery.

[0026] The controller may output information corresponding to a state of at least one of the first inverter or the second inverter.

[0027] The charging system may further include a display unit configured to represent the output information in at least one of a visual manner or an audible manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and other objects, features and other advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0029] Figure 1 is a circuit diagram of a charging system according to an embodiment of the present disclosure;

[0030] Figure 2 is a diagram showing a configuration of a controller applicable to an embodiment of the present disclosure;

[0031] Figure 3 is a circuit diagram illustrating a process of executing a first charging mode in a normal state of a first inverter in a charging system according to an embodiment of the present disclosure;

[0032] Figure 4 is a circuit diagram illustrating a process of executing a first charging mode in a fault state of a first inverter in a charging system according to an embodiment of the present disclosure;

[0033] Figure 5 is a circuit diagram illustrating a process of executing a second charging mode in a charging system according to an embodiment of the present disclosure; and

[0034] Figure 6 is a flowchart illustrating a charging process by a charging system according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0035] For the embodiments of the present disclosure described herein, the specific structural or functional description is merely an example of describing the embodiments of the present disclosure. The embodiments of the present disclosure can be implemented in various forms and should not be interpreted as being limited to the details of the embodiments described in this specification.

[0036] The embodiments may be modified differently and may have various forms. In this regard, specific embodiments are shown in the drawings and described in detail in the specification, but the present disclosure should not be interpreted as being limited to the specific embodiments. It should be appreciated that all changes, equivalents, and substitutions that do not depart from the spirit and scope of the present disclosure are included in the embodiments.

[0037] Unless otherwise defined, the terms used herein (including technical or scientific terms) have the same meanings as those generally understood by those of ordinary skill in the art to which the present disclosure belongs. The terms used herein should be interpreted not only based on the definition of any dictionary, but also based on the meaning used in the art to which the present disclosure belongs. In addition, unless clearly defined, the terms used herein should not be interpreted too ideally or formally.

[0038] Hereinafter, embodiments of the present disclosure are described in detail with reference to the accompanying drawings. Throughout the accompanying drawings, the same or similar elements are represented by the same reference numerals, and redundant descriptions thereof are omitted.

[0039] In the following description of the embodiments, the term "predetermined" means that when the parameter is used in a process or algorithm, the value of the parameter has been previously determined. Depending on the embodiment, the value of the parameter may be set when starting the process or algorithm or during a period of executing the process or algorithm.

[0040] The suffixes “module” and “unit” of the elements herein are used for convenience of description and thus may be used interchangeably without having any distinguishable meanings or functions.

[0041] In the following description of the embodiments of the present disclosure, detailed descriptions of known functions and configurations incorporated herein have been omitted in cases where the subject matter of the embodiments of the present disclosure may be obscured. In addition, the embodiments of the present disclosure should be more clearly understood from the accompanying drawings, and the technical concepts disclosed in the specification are not limited by the accompanying drawings. It should also be understood that all changes, equivalents, and substitutions that do not depart from the spirit and scope of the present disclosure are included in the present disclosure.

[0042] Meanwhile, although terms including ordinal numbers such as first or second may be used to describe various constituent elements, the constituent elements are not limited to these terms, and these terms are used merely for the purpose of distinguishing or discriminating one constituent element from other constituent elements.

[0043] When an element is "connected" or "linked" to another element, it should be understood that the element may be directly connected or linked to another element, or another element may exist between them. Conversely, when an element is "directly connected" or "directly linked" to another element, it should be understood that no other elements exist between them.

[0044] Incidentally, unless clearly used otherwise, a singular expression includes a plural meaning.

[0045] In this specification, the terms "comprising", "including", etc. are intended to express the existence of a feature, number, step, operation, element, component or a combination thereof, and do not exclude the inclusion or existence of another feature, number, step, operation, element, component or any combination thereof or any addition thereof.

[0046] In addition, the term "unit" or "control unit" used in specific terms such as motor control unit (MCU), hybrid control unit (HCU), etc. is merely a term widely used to designate a controller that controls specific functions of a vehicle, and therefore, does not mean a general functional unit.

[0047] The controller may include a communication device configured to communicate with another controller or sensor for controlling the function to be performed thereby. The controller may include a memory configured to store an operating system, logic commands, input / output information, etc. The controller may also include at least one processor configured to perform the identification, calculation, determination, etc. required for controlling the function to be performed.

[0048] The charging system of an electric vehicle according to an embodiment of the present disclosure proposes that by including a switch unit between a switch and each of the first inverter and the second inverter, the first inverter or the second inverter is selectively enabled to perform a boost converter function. Therefore, even when one of the first inverter and the second inverter (e.g., the first inverter, through which the battery is recharged) fails, the battery is continued to be recharged through the other of the first inverter and the second inverter (e.g., the second inverter).

[0049] In the following, reference is made to Figure 1 A configuration of a charging system according to an embodiment of the present disclosure is described.

[0050] Figure 1 is a circuit diagram of a charging system according to an embodiment of the present disclosure.

[0051] Reference Figure 1 , a charging system according to an embodiment of the present disclosure may include a battery 100, a motor 200, a first inverter 310, a second inverter 320, a first switching unit 410, a second switching unit 420, a plurality of switches 500, and a controller 600. The charging system may be connected to an external charger 10.

[0052] Figure 1 The components associated with the description of the embodiments of the present disclosure are mainly shown. The charging system can actually be implemented by including a greater or lesser number of components than the number of components shown and described. Next, each component is described in more detail below.

[0053] The battery 100 may receive DC power to be recharged therewith, or may output DC power for driving a motor. The battery 100 may be implemented by 400V class specifications, 800V class specifications, and the like.

[0054] When the battery 100 is implemented by the 400V class specification, the battery 100 may directly receive the power output from the external charger 10 to be charged therewith regardless of the charging specification of the external charger 10 .

[0055] On the other hand, when the battery 100 is implemented by the 800V class specification, the charging method of the battery 100 may be changed according to the charging specification of the external charger 10 .

[0056] In this case, the charging method may be classified into a first charging mode and a second charging mode. In the first charging mode, the battery 100 is charged by external power that is boosted while passing through the motor 200 and the first inverter 310 or the second inverter 320. In the second charging mode, the external power for charging the battery 100 is directly input to the battery 100 without passing through the motor 200 and the first inverter 310 or the second inverter 320.

[0057] For example, when the battery 100 is implemented by 800V class specifications and the charging specification of the external charger 10 is 500V class, the first charging mode can be performed. Therefore, charging is performed by the external power that is boosted while passing through the motor 200 and the first inverter 310 or the second inverter 320 for boosting the charging voltage.

[0058] On the other hand, when the battery 100 is implemented by the 800V class specification and the charging specification of the external charger 10 is the 1,000V class, the second charging mode can be performed. Therefore, the external power is directly input to the battery 100 without passing through the motor 200 and the first inverter 310 or the second inverter 320 for recharging the battery 100 because the step-up of the input power can be omitted.

[0059] Meanwhile, the motor 200 may have a plurality of coils C1-C3 corresponding to a plurality of phases, respectively. For example, the motor 200 may include three coils corresponding to three phases, respectively.

[0060] The first inverter 310 may include first AC terminals U, V, and W respectively connected to first ends of the plurality of coils C1-C3, and may include first DC terminals D1 and D2 connected to the battery 100. The second inverter 320 may include second AC terminals U', V', and W' respectively connected to second ends of the plurality of coils C1-C3, and may include second DC terminals D1' and D2' connected to the battery 100.

[0061] In addition, each of the first inverter 310 and the second inverter 320 may include a plurality of legs corresponding to the plurality of phases, respectively, to form an electrical connection therewith. Two switching elements may be connected in series to each leg. Each of the plurality of legs may be connected to a corresponding one of the plurality of coils C1-C3 having a phase corresponding thereto.

[0062] In an embodiment of the present disclosure, power input from the external charger 10 may be converted by the first inverter 310 or the second inverter 320 for recharging the battery 100. Power of the battery 100 may be converted by at least one of the first inverter 310 or the second inverter 320 to drive the motor 200.

[0063] In more detail, by enabling the first inverter 310 or the second inverter 320 to receive external power input from the external charger 10 to the neutral point N of the motor 200 at its leg corresponding to the corresponding phase, recharging the battery 100 through the first inverter 310 or the second inverter 320 can be achieved. The power is boosted by controlling the switching elements of each leg and then the boosted power is supplied to the battery 100.

[0064] In addition, driving the motor 200 by at least one of the first inverter 310 or the second inverter 320 can be achieved by enabling at least one of the first inverter 310 or the second inverter 320 to convert the DC power stored in the battery 100 into three-phase AC power. Then, the three-phase AC power is supplied to the motor 200.

[0065] Meanwhile, one end of the first switch unit 410 may be selectively connected to the first end or the second end of each of the plurality of coils C1 - C3 , and the other end of the first switch unit 410 may be connected to the plurality of switches 500 .

[0066] The first switch unit 410 may include a plurality of switches corresponding to each phase. The plurality of switches of the first switch unit 410 may be implemented as, for example, relays or the like.

[0067] One end of each of the plurality of switches 500 may be connected to the other end of the first switch unit 410. The other end of each of the plurality of switches 500 may be short-circuited with each other to form a neutral point N of the motor 200.

[0068] In the case where one end of the first switch unit 410 is connected to the second end of each of the plurality of coils C1-C3, in the on state of the plurality of switches 500, the second end of each of the plurality of coils C1-C3 may be electrically connected to the neutral point N of the motor 200. In this manner, the first inverter 310 may be connected to the motor 200. On the other hand, in the off state of the plurality of switches 500, the other end of each of the plurality of coils C1-C3 may be electrically disconnected from the neutral point N of the motor 200. In this manner, both the first inverter 310 and the second inverter 320 may be connected to the motor 200.

[0069] In the case where one end of the first switch unit 410 is connected to the first end of each of the plurality of coils C1-C3, in the on state of the plurality of switches 500, the first end of each of the plurality of coils C1-C3 may be electrically connected to the neutral point N of the motor 200. In this manner, the second inverter 320 may be connected to the motor 200. On the other hand, in the off state of the plurality of switches 500, the first end of each of the plurality of coils C1-C3 may be electrically disconnected from the neutral point N of the motor 200. In this manner, both the first inverter 310 and the second inverter 320 may be connected to the motor 200.

[0070] According to the setting of the first switch unit 410 as described above, in the on state of the plurality of switches 500, the connection between the neutral point N of the motor 200 and the first inverter 310 and the second inverter 320 can be selectively adjusted. Therefore, the inverter that can be used to recharge the battery 100 can be selected or changed according to the switching state of the first switch unit 410.

[0071] Meanwhile, the switch elements of the first inverter 310 and the second inverter 320 and the plurality of switches 500 may be embodied as various switch elements known in the art. For example, the various switch elements may be metal oxide semiconductor field effect transistors (MOSFETs), insulated gate bipolar transistors (IGBTs), etc. The switch elements of the first inverter 310 and the second inverter 320 and the plurality of switches 500 may be implemented as different types of switch elements, respectively.

[0072] One end of the second switch unit 420 may be connected to an input terminal I1 of external power for battery recharging, and the other end of the second switch unit 420 may be selectively connected to the battery 100 or to the other ends of the plurality of switches 500 .

[0073] According to the setting of the second switch unit 420 as described above, the connection of the input terminal I1 for external power to the battery 100 and the neutral point N can be selectively adjusted. Therefore, the external power can be transmitted to the battery 100 via at least one of the first inverter 310 or the second inverter 320 and the motor 200, or can be directly transmitted to the battery 100.

[0074] In other words, electrical connection relationships corresponding to the first charging mode and the second charging mode respectively as described above may be established.

[0075] The controller 600 may control a switching state of the first switching unit 410 and may be further configured to perform control for a switching state of the second switching unit 420 , pulse width modulation (PWM) control for the first inverter 310 and the second inverter 320 , and the like.

[0076] Specifically, the controller 600 may control the switching state of the first switching unit 410 based on the state of the first inverter 310 when the battery 100 is charged by external power input through the neutral point N.

[0077] When the first inverter 310 is in a normal state, the controller 600 may control the switching state of the first switch unit 410 to control one end of the first switch unit 410 to be connected to the second end of each of the plurality of coils C1-C3. In this case, the first inverter 310 functions as a boost converter, and thus, the battery 100 is charged by the power boosted by the first inverter 310.

[0078] In other words, when the first inverter 310 is in a normal state, the first inverter 310 may be used to recharge the battery 100. Therefore, the first inverter 310 may be implemented to have a higher charging efficiency than the second inverter 320. Of course, this is one embodiment, and the present disclosure is not limited thereto.

[0079] On the other hand, when the first inverter 310 is in a fault state, the controller 600 may control the switching state of the first switch unit 410 so as to control one end of the first switch unit 410 to be connected to the first end of each of the plurality of coils C1-C3. In this case, the second inverter 320 functions as a boost converter, and thus, the battery 100 is charged by the power boosted by the second inverter 320.

[0080] In other words, when the first inverter 310 is in a faulty state, the second inverter 320 may be used to recharge the battery 100. Therefore, the battery 100 may be charged even when the first inverter 310 is faulty.

[0081] Here, the fault state of the first inverter 310 may include at least one of an abnormality in a current sensing value of the first inverter 310 or an excessively high temperature of the first inverter 310. In addition, the fault state of the first inverter 310 may further include a case where charging of the battery 100 by the first inverter 310 cannot be normally performed due to an overcurrent of the plurality of switches 500.

[0082] In more detail, the abnormality of the current sensing value of the first inverter 310 may be determined based on the currents of the first AC terminals U, V, and W and the battery input current Ibat. In addition, the overcurrent of the plurality of switches 500 may be determined based on the battery input current and the current specifications of the plurality of switches.

[0083] For example, the abnormality of the current sensing value of the first inverter 310 may include a case where the sum of the currents of the first AC terminals U, V, and W is not equal to the battery input current Ibat.

[0084] For example, an overcurrent of the plurality of switches 500 may include a situation where the battery input current Ibat exceeds the current specification of the plurality of switches.

[0085] In order to determine the fault state as described above, current sensors and temperature sensors may be provided at multiple points of the connection circuits of the battery 100, the first inverter 310, the second inverter 320, etc. In this case, the controller 600 may determine the state of the first inverter 310 and the second inverter 320 based on the sensed value of each sensor.

[0086] In more detail, the current sensor may be provided between the corresponding legs of the first inverter 310 and the second inverter 320 and the coils C1-C3 corresponding thereto. The current sensor may be implemented to sense the current of each of the first AC terminals U, V and W and the second AC terminals U', V' and W'. The current sensor may also be provided between each of the first DC terminals D1 and D2 and the second DC terminals D1' and D2' and the battery 100. The current sensor may be implemented to sense the battery input current Ibat. In addition, the current sensor may be provided at various other points according to the current to be sensed.

[0087] A temperature sensor may be provided at each switching element of the first inverter 310, and thus, may sense the junction temperature of the first inverter 310. A temperature sensor may also be provided at each switching element of the second inverter 320, and thus, may sense the junction temperature of the second inverter 320.

[0088] Meanwhile, in addition to the current sensor and the temperature sensor, a voltage sensor may be provided at the connection circuit of the battery 100, the first inverter 310, the second inverter 320, etc. according to the embodiment of the present disclosure. For example, the voltage sensor may be provided between the battery 100 and each of the input terminals I1 and I2 of the external power and the first DC terminals D1 and D2.

[0089] Meanwhile, similar to the fault state of the first inverter 310, the fault state of the second inverter 320 may include at least one of an abnormality in a current sensing value of the second inverter 320 or an excessively high temperature of the second inverter 320. In addition, the fault state of the second inverter 320 may further include a case where charging of the battery 100 by the second inverter 320 cannot be normally performed due to an overcurrent of the plurality of switches 500.

[0090] In addition, when the first inverter 310 is in a fault state, the controller 600 may control a switching state of the first switching unit 410 after stopping driving of the first inverter 310 .

[0091] For example, the controller 600 may stop driving of the first inverter 310 by blocking a gate voltage applied to the first inverter 310 .

[0092] In addition, when the first inverter 310 is in a fault state, the controller 600 may control the switching state of the first switching unit 410 after starting to drive the second inverter 320 .

[0093] For example, the controller 600 may start driving the second inverter 320 by applying a gate voltage to the second inverter 320 .

[0094] Meanwhile, the controller 600 may control recharging of the battery 100 based on a state of the second inverter 320 in a state in which one end of the first switching unit 410 is connected to a first end of each of the plurality of coils C1 - C3 .

[0095] For example, when the second inverter 320 is in a fault state, the controller 600 may end the recharging of the battery 100. To this end, the controller 600 may output an output current command for the external charger 10, a driving stop of the second inverter 320, and the like.

[0096] Meanwhile, when the other end of the second switch unit 420 is connected to the other end of the plurality of switches 500 , the controller 600 may control the switching state of the first switch 410 based on the state of the first inverter 310 .

[0097] When the other end of the second switching unit 420 is connected to the neutral point N, the external power may be transmitted to the neutral point N. Therefore, the external power may be transmitted to the battery 100 via the first inverter 310 or the second inverter 320 .

[0098] In other words, when the first charging mode is executed, the controller 600 may control the switching state of the first switching unit 410 based on the state of the first inverter 310 .

[0099] In addition, the controller 600 may control the switching state of the second switch unit 420 based on the voltage command for the external power. In this case, the voltage command for the external power may be obtained from the external charger 10 or its controller, or may be obtained from a separate controller provided in the vehicle.

[0100] In more detail, the controller 600 may control the switching state of the second switch unit 420 based on whether the voltage value according to the voltage command for external power exceeds a predetermined voltage value. In this case, the predetermined voltage value may be set by considering, that is, based on the voltage specification of the battery 100.

[0101] For example, when the voltage value according to the voltage command of the external power exceeds a predetermined voltage value, the controller 600 may control the switch state of the second switch unit 420 so that the other end of the second switch unit 420 is connected to the other end of the plurality of switches 500. In addition, when the voltage value according to the voltage command of the external power does not exceed a predetermined voltage value, the controller 600 may control the switch state of the second switch unit 420 so that the other end of the second switch unit 420 is connected to the battery 100.

[0102] Meanwhile, the controller 600 may output information corresponding to the state of at least one of the first inverter 310 or the second inverter 320. The charging system according to the embodiment of the present disclosure may further include a display unit 700 configured to display information output from the controller 600 in at least one of a visual manner or an auditory manner.

[0103] For example, the display unit 700 may be implemented as an audio, video, and navigation (AVN) device provided in the vehicle, a display device such as a cluster, a voice guidance device, etc.

[0104] In the following, reference Figure 2 An example of the controller 600 applicable to an embodiment of the present disclosure is described.

[0105] Figure 2 is a diagram showing a configuration of a controller applicable to an embodiment of the present disclosure.

[0106] refer to Figure 2 The controller 600 applicable to the embodiment of the present disclosure may be implemented by including a battery management system (BMS), a vehicle control unit (VCU), and a motor control unit (MCU). In addition, the controller 600 may be connected to a charger controller 11 of an external charger 10, a sensor unit 20 including a voltage sensor, a temperature sensor, a current sensor, a gate plate 30, and the like.

[0107] The BMS may provide the VCU with information about the voltage, current, etc. of the battery. The VCU may provide the MCU with information about the voltage, current, etc. of the battery. The MCU may apply a gate signal to the first inverter 310 and the second inverter 320 via the gate plate 30 based on the sensed value received from the sensor unit 20 and the information about the voltage, current, etc. of the battery.

[0108] The MCU may include an analog-to-digital converter (ADC) configured to convert an analog signal into a digital signal and a digital-to-analog converter (DAC) configured to convert a digital signal into an analog signal. The MCU may convert an input analog value into a digital value to output a digital value, or may convert an input digital value into an analog value to output an analog value.

[0109] In addition, the VCU may send a current command to the charger controller 11, or may receive a charger voltage command from the MCU. The VCU may also receive status information of the first inverter 310 and the second inverter 320 based on a sensing value from the MCU.

[0110] The VCU may send a control command for controlling the switching state of the first switching unit 410 based on the state of the first inverter 310 , or may send a control command for controlling the gate signal application of the MCU based on the states of the first inverter 310 and the second inverter 320 .

[0111] Although an example of the controller 600 applicable to the embodiment of the present disclosure has been described, the implementation of the controller 600 is not limited thereto. For example, the controller 600 may be implemented in various forms, for example, using only the VCU or using a separate controller.

[0112] In the following, reference Figures 3 to 5 A charging method for a charging system according to an embodiment of the present disclosure is described.

[0113] Figure 3 is a circuit diagram illustrating a process of performing a first charging mode in a normal state of the first inverter 310 in the charging system according to an embodiment of the present disclosure.

[0114] refer to Figure 3 In the first charging mode, the second switching unit 420 interconnects the external power input terminal I1 with the neutral point N. Thus, the external power is transferred to the neutral point N.

[0115] When the first inverter 310 is in a normal state, the controller 600 controls the switching state of the first switch unit 410 so that the first switch unit 410 interconnects the second end of each of the plurality of coils C1-C3 and the neutral point N. Therefore, the external power is transmitted to the battery 100 after being boosted through the plurality of coils C1-C3 and the first inverter 310. Thus, recharging is performed.

[0116] Figure 4 is a circuit diagram illustrating a process of performing a first charging mode in a fault state of the first inverter 310 in the charging system according to an embodiment of the present disclosure.

[0117] Reference Figure 4 In the first charging mode, the second switching unit 420 interconnects the external power input terminal I1 with the neutral point N. Thus, the external power is transferred to the neutral point N.

[0118] When the first inverter 310 is in a fault state, the controller 600 controls the switching state of the first switch unit 410 so that the first switch unit 410 interconnects the first end of each of the plurality of coils C1-C3 and the neutral point N. Therefore, the external power is transmitted to the battery 100 after being boosted through the plurality of coils C1-C3 and the second inverter 320. Thus, recharging is performed.

[0119] Figure 5 is a circuit diagram illustrating a process of executing a second charging mode in a charging system according to an embodiment of the present disclosure.

[0120] refer to Figure 5 In the second charging mode, the second switch unit 420 directly interconnects the external power input terminal I1 and the battery 100. Thus, the external power is not transmitted to the neutral point N but directly transmitted to the battery 100.

[0121] According to various embodiments of the present disclosure as described above, even when one inverter performing a boost converter function fails during charging of a battery in a charged vehicle, charging of the battery can be continued by another inverter without immediate stopping.

[0122] When information about the fault status of the inverter is provided, a vehicle driver or other user may recognize the status of the inverter and may therefore take appropriate action.

[0123] Figure 6 is a flowchart illustrating a charging process by a charging system according to an embodiment of the present disclosure.

[0124] refer to Figure 6 , the controller 600 first receives the output voltage command of the external charger 10 and the input voltage of the battery 100 (S601 and S602). Then, the controller 600 starts the PWM control of the first inverter 310 (S604) while disconnecting the second inverter 320 (S603) to start recharging the battery 100.

[0125] Thereafter, the controller 600 transmits an output current command to the external charger 10 (S605). Then, the external charger 10 receiving the output current command starts current control (S606). Thus, charging of the battery 100 is performed.

[0126] The controller 600 senses the current of each phase and the battery input current during the recharging process of the battery 100 (S607). The controller 600 then determines whether the sum of the currents of each phase is equal to the battery input current. The controller 600 then determines whether the battery input current Ibat is within the current specifications of the plurality of switches (S608), and determines whether the temperature of the first inverter 310 is within a normal range (S609).

[0127] If the sum of the currents of each phase (Iu+Iv+Iw) is equal to the battery input current Ibat (Iu+Iv+Iw=Ibat), and the battery input current Ibat is the current specification of the plurality of switches, and the temperature of the first inverter 310 is within the normal range, the controller 600 determines that the first inverter 310 is in a normal state (S610). The controller 600 then controls one end of the first switch unit 410 to be connected to the second end of each of the plurality of coils, thereby enabling the battery 100 to be recharged through the first inverter 310.

[0128] On the other hand, if the sum of the currents of each phase (Iu+Iv+Iw) is not equal to the battery input current Ibat (Iu+Iv+Iw≠Ibat), or the battery input current Ibat is not within the specification of multiple switches ("No" in S608), and the temperature of the first inverter 310 is not within the normal range ("No" in S609), the controller 600 may determine that the first inverter 310 is in a fault state due to an abnormal current sensing value or overcurrent (S611) or excessive temperature (S612).

[0129] In this case (S611 or S612), the controller 600 may turn off the first inverter 310, may turn on the second inverter 320, and then may control the switching state of the first switch unit 410. The switching state of the first switch unit 410 may be controlled so that one end of the first switch unit 410 is connected to the first end of each of the plurality of coils (S615) so that the battery 100 can be recharged through the second inverter 320.

[0130] After completing the preparation as described above, the controller 600 starts PWM control of the second inverter 320 (S616), and sends the output current command to the external charger 10 again (S617). Then, the external charger 10 that has received the new output current command starts current control according to the new output current command (S618). Then, charging of the battery 100 is performed through the second inverter 320.

[0131] Similar to the above process, during the charging process through the second inverter 320, the controller 600 senses the current of each phase and the battery input current (S619). Then, the controller 600 determines whether the sum of the currents of each phase is equal to the battery input current Ibat, and whether the battery input current Ibat is under the regulations of the plurality of switches (S620). It is determined whether the temperature of the second inverter 320 is within a normal range (S621).

[0132] If the sum of each phase current (Iu'+Iv'+Iw') is equal to the detected battery input current Ibat (Iu'+Iv'+Iw'=Ibat), and the battery input current Ibat is the specification of the plurality of switches, and the temperature of the second inverter 320 is within the normal range, the controller 600 determines that the second inverter 320 is in a normal state (S620 and S621). The controller 600 then performs control for continuously recharging the battery 100 through the second inverter 320 in a state where one end of the first switch unit 410 is connected to the first end of each of the plurality of coils C1-C3.

[0133] On the other hand, when the sum of the currents of each phase (Iu'+Iv'+Iw') is not equal to the detected battery input current Ibat (Iu'+Iv'+Iw'≠Ibat) or the battery input current (Ibat) is not within the specified range of the multiple switches (No in S620), and the temperature of the second inverter 320 is either not within the normal range (No in S621), the controller 600 may determine that the second inverter 320 is in a fault state due to an abnormal current sensing value or overcurrent (S622) or excessive temperature (S623).

[0134] When the second inverter 320 is in a fault state (S622 and S623), it is impossible to normally charge the battery 100 through the first inverter 310 and the second inverter 320. Therefore, in this case, the controller 600 sends an output current instruction to the external charger 10 (S624) and disconnects the second inverter 320 (S625). In addition, the external charger 10 stops current control according to the received output current instruction (S626). As a result, charging ends.

[0135] On the other hand, when both the first inverter 310 and the second inverter 320 are in a fault state (S611, S612, S622, and S623), the controller 600 may output information corresponding to the state of the first inverter 310 and the second inverter 320. The display unit 700 that obtains the information may visually and / or audibly indicate the state of the first inverter 310 and the second inverter 320 so that the vehicle driver or other users can recognize the change in the charging mode, whether to stop charging, the reason thereof, etc.

[0136] According to various embodiments of the present disclosure as described above, even when one inverter performing a boost converter function fails during charging of a battery in a charged vehicle, charging of the battery can be continued by another inverter without immediate stopping.

[0137] When information about the fault status of the inverter is provided, a vehicle driver or other user may recognize the status of the inverter and may therefore take appropriate action.

[0138] The effects obtainable according to the present disclosure are not limited to the above-mentioned effects. Other effects of the present disclosure that have not been described should be more clearly understood by those skilled in the art from the appended claims.

[0139] Although the embodiments of the present disclosure have been described in detail with reference to the accompanying drawings, the present disclosure is not limited to the disclosed embodiments. Various changes may be made to the embodiments without departing from the principles and spirit of the present disclosure. Therefore, the disclosed embodiments are considered to be illustrative and not restrictive in all aspects. The scope of the present disclosure is indicated by the attached claims rather than the foregoing description. All changes within the meaning and scope of equivalents of the present disclosure are intended to be included therein.

Claims

1. A charging system for an electric vehicle, the charging system comprising: a battery configured to receive or output DC power; A motor having a plurality of coils corresponding to the plurality of phases respectively; a first inverter having a first AC terminal connected to a first end of each of the plurality of coils, respectively, and having a first DC terminal connected to the battery; a second inverter having a second AC terminal connected to a second end of each of the plurality of coils, respectively, and having a second DC terminal connected to the battery; A first switch unit having one end selectively connected to the first end or the second end of the plurality of coils; a plurality of switches, one end of each of the switches being connected to the other end of the first switch unit and the other end of each of the switches being short-circuited to form a neutral point of the motor; as well as A controller is configured to control the switching state of the first switch unit.

2. The charging system according to claim 1, wherein: When the battery is recharged with external power input through the neutral point, the controller controls a switching state of the first switching unit based on a state of the first inverter.

3. The charging system according to claim 2, wherein: When the first inverter is in a normal state, the controller controls a switching state of the first switch unit so that one end of the first switch unit is connected to the second ends of the plurality of coils.

4. The charging system according to claim 2, wherein: When the first inverter is in a fault state, the controller controls a switching state of the first switch unit so that one end of the first switch unit is connected to the first ends of the plurality of coils.

5. The charging system according to claim 4, wherein: The fault state of the first inverter includes at least one of abnormality of a current sensing value of the first inverter or excessive temperature of the first inverter.

6. The charging system according to claim 5, wherein: The abnormality of the current sensing value of the first inverter is determined based on the current of each of the first AC terminals and the battery input current.

7. The charging system according to claim 4, wherein: When the first inverter is in a fault state, the controller controls a switching state of the first switching unit after stopping driving of the first inverter.

8. The charging system according to claim 4, wherein: When the first inverter is in a fault state, the controller controls a switching state of the first switching unit after starting driving of the second inverter.

9. The charging system according to claim 4, wherein: The controller controls recharging of the battery based on a state of the second inverter under the condition that one end of the first switching unit is connected to the first ends of the plurality of coils.

10. The charging system according to claim 9, wherein: When the second inverter is in a fault state, the controller ends recharging of the battery.

11. The charging system according to claim 1, further comprising: A second switch unit having one end connected to an input terminal of external power for recharging the battery and another end selectively connected to the battery or another end of the plurality of switches.

12. The charging system according to claim 11, wherein: When the other end of the second switch unit is connected to the other ends of the plurality of switches, the controller controls a switching state of the first switch unit based on a state of the first inverter.

13. The charging system according to claim 11, wherein: The controller controls a switching state of the second switching unit based on a voltage command of the external power.

14. The charging system according to claim 13, wherein: The controller controls a switching state of the second switching unit based on whether a voltage value according to the voltage command exceeds a predetermined voltage value set based on a voltage specification of the battery.

15. The charging system according to claim 14, wherein: When the voltage value according to the voltage command exceeds the predetermined voltage value, the controller controls a switching state of the second switch unit so that the other end of the second switch unit is connected to the other ends of the plurality of switches.

16. The charging system according to claim 14, wherein: When the voltage value according to the voltage command does not exceed the predetermined voltage value, the controller controls a switching state of the second switch unit so that the other end of the second switch unit is connected to the battery.

17. The charging system according to claim 1, wherein: The controller outputs information corresponding to a state of at least one of the first inverter or the second inverter.

18. The charging system according to claim 17, further comprising: The display unit is configured to display output information in at least one of a visual manner and an auditory manner.

Images