Vehicle and Its Control Method

Abstract

The present invention relates to a vehicle and a control method thereof. The vehicle may include a motor, an inverter, a battery, a first current sensor, a second current sensor, a third current sensor, and a controller. The motor includes a neutral node and a first winding, a second winding, and a third winding connected to the neutral node; the inverter includes a first switching element, a second switching element, and a third switching element; the battery is configured to receive a boosted voltage; the controller may determine an average duty ratio of a pulse width modulation signal based on a charging voltage and a battery voltage of the battery, and determine a duty ratio of the pulse width modulation signal. When the first current sensor fails, the controller may determine a duty ratio of the pulse width modulation signal provided to the first switching element based on the average duty ratio of the pulse width modulation signal provided to the inverter, the duty ratio of the pulse width modulation signal provided to the second switching element, and the duty ratio of the pulse width modulation signal provided to the third switching element.

Description

[0001] Cross - reference to related applications

[0002] This application claims the priority and benefit of Korean Patent Application No. 10 - 2020 - 0068021, filed on June 5, 2020, the entire content of which is incorporated herein by reference for all purposes. Technical field

[0003] The present invention relates to a vehicle and a control method thereof, and more particularly to a vehicle and a control method thereof that are configured to continue charging a battery even when a current sensor for measuring three - phase current fails during battery charging. Background art

[0004] Generally, an electric vehicle or a plug - in hybrid vehicle can charge a battery in the vehicle by receiving power provided from an external charging device, and drive a motor by using electric energy stored in the charged battery to generate power for the vehicle.

[0005] In - vehicle battery charging methods are classified into a slow - charging method and a fast - charging method. The slow - charging method uses an in - vehicle charging device (which receives external AC charging power and converts it into DC charging power suitable for battery charging size) to charge the battery at a relatively low speed; the fast - charging method charges the battery quickly by directly supplying external DC charging power to the battery.

[0006] In the case of the fast - charging method, by supplying direct - current (DC) power converted by an external charging device to the battery of the vehicle, the battery can be charged at a high power. Summary of the invention

[0007] Aspects of the present invention are directed to providing a vehicle and a control method thereof that are configured to continue charging a battery even when a current sensor for measuring three - phase current fails.

[0008] According to one aspect of the present invention, a vehicle may include a motor, an inverter, a battery, a first current sensor, a second current sensor, a third current sensor, and a controller. The motor includes: a neutral node that receives a charging voltage from a charging device; and a first winding, a second winding, and a third winding that are connected to the neutral node. The inverter includes: a first switching element connected to the first winding; a second switching element connected to the second winding; a third switching element connected to the third winding, and the inverter is configured to boost the charging voltage provided by the charging device. The battery is configured to receive the boosted voltage boosted by the inverter. The first current sensor is configured to measure a first phase current flowing through the first winding. The second current sensor is configured to measure a second phase current flowing through the second winding. The third current sensor is configured to measure a third phase current flowing through the third winding. When the first current sensor fails, the controller may determine the duty ratio of the pulse width modulation signal provided to the first switching element based on the average duty ratio of the pulse width modulation signal provided to the inverter, the duty ratio of the pulse width modulation signal provided to the second switching element, and the duty ratio of the pulse width modulation signal provided to the third switching element.

[0009] The controller may determine the duty ratio of the pulse width modulation signal provided to the first switching element such that the average value of the duty ratio of the pulse width modulation signal provided to the first switching element, the duty ratio of the pulse width modulation signal provided to the second switching element, and the duty ratio of the pulse width modulation signal provided to the third switching element is the average duty ratio of the pulse width modulation signal provided to the inverter.

[0010] When the first current sensor and the second current sensor fail, the controller may determine the duty ratios of the pulse width modulation signals provided to the first switching element and the second switching element based on the average duty ratio of the pulse width modulation signal provided to the inverter and the duty ratio of the pulse width modulation signal provided to the third switching element.

[0011] The controller may determine the duty ratios of the pulse width modulation signals provided to the first switching element and the second switching element such that the average value of the duty ratio of the pulse width modulation signal provided to the first switching element, the duty ratio of the pulse width modulation signal provided to the second switching element, and the duty ratio of the pulse width modulation signal provided to the third switching element is the average duty ratio of the pulse width modulation signal provided to the inverter.

[0012] The controller may equivalently determine the duty ratios of the pulse width modulation signals provided to the first switching element and the second switching element.

[0013] Only when at least one of the first current sensor, the second current sensor, and the third current sensor is operating normally, the controller may perform pulse width modulation control on the inverter.

[0014] The vehicle may further include: a temperature sensor configured to measure the temperature of each first switching element, each second switching element, and each third switching element, and the controller may perform pulse width modulation control on the inverter only when the temperature measured by the temperature sensor is less than a preset temperature.

[0015] The controller may perform pulse width modulation control on the inverter such that the ON periods of the pulse width modulation signals supplied to the first switching element, the ON periods of the pulse width modulation signals supplied to the second switching element, and the ON periods of the pulse width modulation signals supplied to the third switching element are staggered.

[0016] The vehicle may further include: an input / output port connected to a charging device; a first relay connected between the upper switching element of the inverter and the input / output port; a second relay connected between the neutral node and the input / output port; and a third relay connected between the lower switching element of the inverter and the input / output port; when the charging voltage supplied from the charging device is less than the battery voltage of the battery, the controller may close the second relay and the third relay and open the first relay.

[0017] When the charging voltage supplied from the charging device is greater than or equal to the battery voltage of the battery, the controller may close the first relay and the third relay and open the second relay.

[0018] According to an aspect of the present invention, a control method of a vehicle may include: receiving a charging voltage from a charging device through a neutral node of a motor; boosting the charging voltage supplied from the charging device by an inverter connected to the motor; receiving the boosted voltage boosted by the inverter; measuring a first phase current flowing through a first winding of the motor by a first current sensor; measuring a second phase current flowing through a second winding of the motor by a second current sensor; measuring a third phase current flowing through a third winding of the motor by a third current sensor; determining an average duty ratio of a pulse width modulation signal supplied to the inverter based on the charging voltage and the battery voltage of the battery; determining a duty ratio of a pulse width modulation signal supplied to each of the first switching element, the second switching element, and the third switching element based on the first phase current, the second phase current, and the third phase current; when the first current sensor fails, determining a duty ratio of a pulse width modulation signal supplied to the first switching element based on the average duty ratio of the pulse width modulation signal supplied to the inverter, the duty ratio of the pulse width modulation signal supplied to the second switching element, and the duty ratio of the pulse width modulation signal supplied to the third switching element.

[0019] Determining the duty cycle of the pulse width modulation signal provided to the first switching element may include: determining that the average of the duty cycles of the pulse width modulation signals provided to the first switching element, the pulse width modulation signal provided to the second switching element, and the pulse width modulation signal provided to the third switching element is the average duty cycle of the pulse width modulation signal provided to the inverter.

[0020] The method may further include: when the first current sensor and the second current sensor fail, determining the duty cycles of the pulse width modulation signals provided to the first switching element and the second switching element based on the average duty cycle of the pulse width modulation signal provided to the inverter and the duty cycle of the pulse width modulation signal provided to the third switching element.

[0021] Determining the duty cycles of the pulse width modulation signals provided to the first switching element and the second switching element may include: determining the duty cycles of the pulse width modulation signals provided to the first switching element and the second switching element such that the average of the duty cycle of the pulse width modulation signal provided to the first switching element, the duty cycle of the pulse width modulation signal provided to the second switching element, and the duty cycle of the pulse width modulation signal provided to the third switching element is the average duty cycle of the pulse width modulation signal provided to the inverter.

[0022] Determining the duty cycles of the pulse width modulation signals provided to the first switching element and the second switching element may include: equivalently determining the duty cycles of the pulse width modulation signals provided to the first switching element and the second switching element.

[0023] The method may further include: performing pulse width modulation control on the inverter only when at least one of the first current sensor, the second current sensor, and the third current sensor is operating normally.

[0024] The method may further include: measuring the temperatures of each first switching element, each second switching element, and each third switching element, and performing pulse width modulation control on the inverter only when the temperature measured by the temperature sensor is lower than a preset temperature.

[0025] The method may further include: performing pulse width modulation control on the inverter such that the conduction periods of the pulse width modulation signals provided to the first switching element, the conduction periods of the pulse width modulation signals provided to the second switching element, and the conduction periods of the pulse width modulation signals provided to the third switching element are staggered.

[0026] The method may further include: when the charging voltage provided from the charging device is less than the battery voltage of the battery, closing the second relay connected between the neutral node and the input / output port and the third relay connected between the lower switching element of the inverter and the input / output port, and opening the first relay connected between the upper switching element of the inverter and the input / output port.

[0027] The method may further include: when the charging voltage provided by the charging device is greater than or equal to the battery voltage of the battery, closing the first relay and the third relay and opening the second relay. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] To better understand the present invention, various embodiments of the present invention given by way of example will now be described with reference to the accompanying drawings, in which:

[0029] Figure 1 is a block diagram of a charging system included in a vehicle according to an embodiment of the present invention.

[0030] Figure 2 is a control block diagram of a vehicle according to an embodiment of the present invention.

[0031] Figure 3 is a flowchart showing the vehicle control according to an embodiment of the present invention.

[0032] Figure 4 is an exemplary diagram showing the pulse width modulation (PWM) signal applied to the inverter and the three-phase current changing with time according to the signal.

[0033] The drawings depicted herein are for illustrative purposes only and are not intended to limit the scope of the present invention in any way. DETAILED DESCRIPTION

[0034] Reference will now be made in detail to various embodiments of the present invention, examples of which are illustrated in the accompanying drawings and described below. Although the present invention will be described in conjunction with the exemplary embodiments of the present invention, it should be understood that this specification is not intended to limit the present invention to those exemplary embodiments. On the other hand, the present invention is intended to cover not only the exemplary embodiments of the present invention, but also various alternative forms, modifications, equivalents and other embodiments that may be included within the spirit and scope of the present invention as defined by the appended claims.

[0035] In the following description, throughout the specification, the same reference numerals denote the same elements. This specification does not describe all elements of the embodiments, and in the technical field, there is no overlap in the general content or between the embodiments. Terms such as "unit", "module", "component" and "block" can be implemented as software or hardware. According to an embodiment, a plurality of "units", "modules", "components" and "blocks" can be implemented as a single component, or a single "unit", "module", "component" and "block" can include a plurality of components.

[0036] It should be understood that when an element is referred to as being "connected" to another element, it can be directly or indirectly connected to the other element, where indirect connection includes "connected via a wireless communication network".

[0037] In addition, when a component "includes" or "contains" an element, unless there is a contrary specific description, the component may further include other elements without excluding other elements. Additionally, the term "unit" used in the specification refers to a hardware component such as software, FPGA, or ASIC, and the "unit" performs certain functions. However, the "unit" is not intended to be limited to software or hardware. The "unit" can be configured to be located in an addressable storage medium or can be configured to reproduce one or more processors. Thus, as an example, a "unit" refers to components (such as software components, object-oriented software components, class components, and task components), processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within a component and a "unit" can be combined into a smaller number of components and "units" or can be further separated into other components and "units".

[0038] Embodiments of the present invention will be described below with reference to the accompanying drawings. And, to clearly describe the content disclosed in the drawings, parts irrelevant to the description will be omitted. Additionally, in the drawings, the same reference numerals denote the same components, and redundant descriptions thereof will be omitted.

[0039] Figure 1 is a block diagram of a charging system included in a vehicle according to an embodiment, Figure 2 is a control block diagram of a vehicle according to an embodiment.

[0040] In the case of a fast charging method, an external fast charging device may not be able to provide a voltage sufficient to charge the battery of the vehicle. For example, an external fast charging device for fast charging can be manufactured to output a single voltage specification of 400V, while the battery used in the vehicle can be designed to have a voltage specification of 800V or higher.

[0041] In this case, the fast charging device provides a charging voltage of 400V, but the battery used in the vehicle has a voltage specification of 800V or higher. Therefore, it is not possible to charge the battery by directly connecting the fast charging device to the vehicle. Thus, during charging, a boost converter needs to be used separately to boost the voltage provided by the external charging device.

[0042] However, the boost converter for boosting the voltage provided by the external charging device is not only very large in weight and volume but also expensive, which may lead to an increase in the vehicle price.

[0043] To solve this problem, the vehicle according to the embodiment may not have a separate converter, and boost the charging voltage of the charging device by using a conventional motor and an inverter to charge the battery at a high voltage.

[0044] Reference Figure 1 , the charging system included in the vehicle 1 according to the embodiment includes a battery 110, an inverter 120, a motor 130, and a plurality of relays R provided in the vehicle 1 1 , R 2 and R 3 .

[0045] Generally, the system for driving the motor 130 includes a battery 110 and an inverter 120. The battery 110 is an energy storage device that stores the power for driving the motor 130; the inverter 120 converts the direct current stored in the battery 110 into three-phase alternating current and supplies it to the motor 130.

[0046] The inverter 120 may have a DC connection terminal including a positive (+) terminal 121p and a negative (-) terminal 121n respectively connected to both ends of the battery 110, and three branches connected in parallel between the DC connection terminals. Each branch has two switching elements (S11 and S12, or S13 and S14, or S15 and S16) connected in series with each other. The connection nodes of the two switching elements may be respectively connected to the corresponding windings 130a, 130b, and 130c of the motor 130. Each of the windings 130a, 130b, and 130c of the motor 130 may be made of insulated wire into a coil.

[0047] In other words, the inverter 120 includes three upper switching elements (S11, S13, S15) and three lower switching elements (S12, S14, S16). Each of the upper switching elements (S11, S13, S15) is connected to any one of the three lower switching elements (S12, S14, S16), and the connection nodes where the upper switching elements S11, S13, and S15 are connected to the lower switching elements S12, S14, and S16 may be respectively connected to the windings 130a, 130b, and 130c of the motor 130.

[0048] The plurality of switching elements S11 to S16 included in the inverter 120 may refer to insulated gate bipolar transistors (IGBTs), and the on / off of the switching elements S11 to S16 may be controlled according to the gate voltage supplied to the gate.

[0049] Hereinafter, for convenience of description, the upper switching elements S11 and the lower switching elements S12 connected to the first winding 130a of the motor 130 are referred to as the first switching elements S11 and S12, the upper switching elements S13 and the lower switching elements S14 connected to the second winding 130b of the motor 130 are referred to as the second switching elements S13 and S14, and the upper switching elements S15 and the lower switching elements S16 connected to the third winding 130c of the motor 130 are referred to as the third switching elements S15 and S16.

[0050] In order to supply as much current to the motor 130 as the current command corresponding to the torque of the motor 130 (which is obtained by driving the motor 130), pulse width modulation (PWM) control can be performed on the switching elements S11 to S16 in the inverter 120. In this way, the energy flow for driving the motor 130 flows from the battery 110 to the motor 130.

[0051] On the other hand, the energy flow for charging the battery 110 can flow from the motor 130 to the battery 110.

[0052] Specifically, power supply can be performed in the direction from the neutral node (N) of the motor 130 to the DC connection terminals 121p and 121n of the inverter 120. At this time, each of the first switching elements S11 and S12, the second switching elements S13 and S14, and the third switching elements S15 and S16, and each of the first winding 130a, the second winding 130b, and the third winding 130c can be configured as a DC converter circuit that boosts the voltage supplied to the neutral node N (which is connected to the first winding 130a, the second winding 130b, and the third winding 130c) to the DC connection terminals 121p and 121n.

[0053] Therefore, the connection structure between the inverter 120 and the windings 130a, 130b, 130c in the motor 130 is the same as that of a total of three converter circuits connected in parallel. By simultaneously or selectively operating a plurality of DC converters connected in parallel, or by controlling the switching elements S11 to S16 to be interleavedly operated by the controller 150, the voltage of the neutral node (N) can be boosted and supplied to the battery 110.

[0054] The vehicle 1 according to the embodiment can selectively utilize a first charging mode and a second charging mode; in the first charging mode, based on the maximum voltage (V EVSE.max ) of the external charging power supplied from the external charging device 200 to the charging input / output port 140 of the vehicle 1 and the battery voltage (V BAT)In the first charging mode, external charging power is directly supplied to the battery 110; in the second charging mode, after supplying the external charging power to the neutral node (N) of the motor 130, the voltage supplied to the neutral node N is boosted by controlling the switching elements of the inverter 120 and then supplied to the battery 110.

[0055] As described above, the process of charging the battery 110 using the charging system of the vehicle 1 has been briefly described.

[0056] Meanwhile, in the vehicle 1 according to the above-described embodiment, when any one of the current sensors for measuring the three-phase current fails, the charging of the battery may stop. If the charging is interrupted due to a current sensor failure, it is impossible to charge the battery again without repairing or replacing the current sensor, which may cause inconvenience to the user.

[0057] Hereinafter, the functions of each component of the charging system included in the vehicle 1 according to the exemplary embodiment will be described in detail, thereby describing a method of continuously charging the battery without interruption even when the current sensor fails.

[0058] Reference Figure 1 and Figure 2 , the vehicle 1 according to the embodiment includes a sensor 160, a relay R, an inverter 120, and a controller 150. The sensor 160 detects the output values of each component of the charging system; the relay R is used to change the battery charging mode; the inverter 120 is used to boost the voltage supplied from the charging device 200; the controller 150 controls the relay R and the inverter 120 based on the detection value of the sensor 160 and the information on the charging voltage received from the charging device 200.

[0059] The sensor 160 according to the embodiment includes a current sensor 121a, a current sensor 121b, and a current sensor 121c. The current sensor 121a (hereinafter referred to as the "first current sensor") measures the first-phase current I1 flowing through the first winding 130a of the motor 130; the current sensor 121b (hereinafter referred to as the "second current sensor") measures the second-phase current I2 flowing through the second winding 130b of the motor 130; the current sensor 121c (hereinafter referred to as the "third current sensor") is used to measure the third-phase current I3 flowing through the third winding 130c of the motor 130. For example, a Hall-type current sensor can be used as the current sensors 121a, 121b, and 121c.

[0060] The first-phase current I1, the second-phase current I2, and the third-phase current I3 can each represent any one of the U-phase current, the V-phase current, and the W-phase current. For example, the first-phase current I1 can be the U-phase current, the second-phase current I2 can be the V-phase current, and the third-phase current I3 can be the W-phase current, but it is not limited thereto.

[0061] Current sensors 121a, 121b, and 121c can send the measured current to the controller 150.

[0062] The sensor 160 may include temperature sensors T11, T12, T13, T14, T15, and T16, which are provided in each of a plurality of switching elements S11 to S16 included in the inverter 120.

[0063] The sensor 160 may include a first voltage sensor (not shown) and a second voltage sensor (not shown). The first voltage sensor can measure the voltage V provided to the neutral node N of the motor 130 by measuring the potential difference across both ends of a first capacitor C connected to both ends of the input / output port 140. n ; The second voltage sensor can measure the battery voltage V of the battery 110 by measuring the potential difference across both ends of a second capacitor C connected to both ends of the battery 110. n b BAT .

[0064] The voltage measured by the first voltage sensor (not shown) and the voltage measured by the second voltage sensor (not shown) can be sent to the controller 150.

[0065] The sensor 160 may further include temperature sensors T11 to T16, which measure the temperature of each of a plurality of switching elements S11 to S16 included in the inverter 120. For example, chip-type temperature sensors can be used as the temperature sensors T11 to T16.

[0066] The temperature values of the plurality of switching elements S11 to S16 measured by the temperature sensors T1 to T16 can be sent to the controller 150.

[0067] According to an embodiment, the relay R may include a plurality of relays R provided between the input / output port 140 connected to the external charging device 200 and the battery 110. 1 2 3 .

[0068] Specifically, the relay R may include a relay R (hereinafter referred to as the "first relay") connected between the upper switching elements S11, S13, S15 of the inverter 120 and the input / output port 140, and a relay R connected between the neutral node (N) of the motor 130 and the input / output port 140. 1 (hereinafter referred to as the "first relay"), and a relay R connected between the neutral node (N) of the motor 130 and the input / output port 140. 2(hereinafter referred to as the "second relay"), and a relay R connected between the lower switching elements S12, S14, and S16 of the inverter 120 and the input / output port 140 3 (hereinafter referred to as the "third relay").

[0069] A plurality of relays R 1 、R 2 and R 3 Each of them can be closed or opened according to a control signal from the controller 150 to change the charging mode of the battery 110.

[0070] As described above, the inverter 120 may include a plurality of switching elements S11 to S16, and may boost the voltage provided to the neutral node N of the motor 130 and supply it to the battery 110.

[0071] The controller 150 may control the relay R and the inverter 120 based on various output values received from the sensor 160 and / or the maximum charging voltage (V EVSE.max ) received from the charging device 200.

[0072] For example, the controller 150 can be based on the maximum charging voltage (V EVSE.max ) received from the charging device 200 or the voltage (V n ) measured across the first capacitor (C n ) and the battery voltage (V BAT ) of the battery 110 (which is the voltage measured across the second capacitor (C b )) to control the relay R.

[0073] Specifically, when the magnitude of the charging voltage V n provided by the charging device 200 is smaller than the battery voltage V BAT of the battery 110, the controller 150 can close the second relay R 2 and the third relay R 3 and open the first relay R 1 . Therefore, the charging mode of the battery 110 can be changed to the second charging mode.

[0074] In addition, when the magnitude of the charging voltage V n provided by the charging device 200 is greater than the battery voltage V BAT of the battery 110, the controller 150 can close the first relay R 1 and the third relay R 3 and open the second relay R 2 . Therefore, the charging mode of the battery 110 can be changed to the first charging mode.

[0075] The controller 150 may determine an average duty ratio (D) of a pulse width modulation signal provided to the inverter 120 based on a charging voltage V supplied to the neutral node N of the motor 130 and a battery voltage V of the battery 110, and perform pulse width modulation control on the inverter 120 based on the determined average duty ratio D. n and the battery voltage V of the battery 110 BAT to determine an average duty ratio (D) of a pulse width modulation signal provided to the inverter 120, and perform pulse width modulation control on the inverter 120 based on the determined average duty ratio D.

[0076] However, the controller 150 may perform pulse width modulation control on the inverter 120 only when it is determined that at least one current sensor (121a, 121b, 121c) is operating normally or the temperatures of all of the plurality of switching elements (S11 to S16) are lower than a preset temperature.

[0077] In other words, if it is determined that all of the current sensors 121a, 121b, 121c have failed or the temperature of at least one of the plurality of switching elements S11 to S16 is greater than the preset temperature, the charging process may be stopped for safety reasons.

[0078] The controller 150 for performing the above-described operations or operations to be described later includes an algorithm for controlling various configurations of the vehicle 1 (such as the inverter 120 and the relay R), or a memory for storing data of a program for reproducing the algorithm, and a processor for performing the above-described operations using the data stored in the memory.

[0079] In this case, the memory and the processor may be implemented as separate chips, but the memory and the processor may also be implemented as a single chip.

[0080] The controller 150 may be implemented in the form of a vehicle controller, a motor controller, or a battery management system provided in an existing vehicle, or may be additionally provided in the vehicle.

[0081] Specific operations and functions of the controller 150 will be described in detail below.

[0082] Figure 3 is a flowchart illustrating vehicle control according to an embodiment.

[0083] Referring to Figure 3 , the controller 150 may detect the connection of the charging device 200 and receive information (1000) about a maximum charging voltage V EVSE.max from the charging device 200.

[0084] As described above, the controller 150 may determine a charging mode of the battery 110 based on the battery voltage (V BAT ) of the battery 110 and the maximum charging voltage (V EVSE.max ) of the charging device 200. Hereinafter, it is assumed that the charging mode of the battery 110 is the second charging mode.

[0085] The controller 150 may determine the average duty ratio (D) of the pulse width modulation signal supplied to the inverter 120 based on the charging voltage (V n ) supplied to the neutral node (N) of the motor 130 and the battery voltage (V BAT ) of the battery 110.

[0086] Specifically, the controller 150 may determine the average duty ratio (D) of the pulse width modulation signal based on the following equation.

[0087] [Equation 1]

[0088] D = 1 - V n / V BAT

[0089] For example, when the battery voltage V BAT of the battery 110 is 800V and the charging voltage V n is 400V, the average duty ratio D may be determined to be 0.5.

[0090] In this case, the duty ratio may represent the ratio between the (on period) and the (on period + off period) of the switching elements S11 to S16. For example, if the (on period + off period) of the switching elements S11 to S16 is 2 seconds and the (on period) is 1 second, the duty ratio may be determined to be 0.5.

[0091] The first current sensor 121a measures the first-phase current I1 flowing through the first winding 130a, the second current sensor 121b measures the second-phase current I2 flowing through the second winding 130b, the third current sensor 121c may measure the third-phase current I3 flowing through the third winding 130c, and the controller 150 may receive the current values (1200) measured by the first current sensor 121a, the second current sensor 121b, and the third current sensor 121c.

[0092] The controller 150 may determine the duty ratio D1 of the pulse width modulation signal supplied to the first switching elements (S11, S12), the duty ratio D2 of the pulse width modulation signal supplied to the second switching elements S13 and S14, and the duty ratio D3 of the pulse width modulation signal supplied to the third switching elements S15 and S16 based on the current values measured by each current sensor (121a, 121b, 121c) such that the first-phase current I1, the second-phase current I2, and the third-phase current I3 become the same.

[0093] For example, when the magnitude of the first-phase current I1 is the same as the magnitude of the second-phase current I2 and the magnitude of the third-phase current I3 is less than the magnitude of the first-phase current I1, the controller reduces the duty ratios (D1, D2) of the pulse-width modulation signals supplied to the first switching elements (S11, S12) and the second switching elements (S13, S14), and increases the duty ratio D3 of the pulse-width modulation signal supplied to the third switching elements S15 and S16.

[0094] In this way, by performing feedback control on the current values measured by the current sensors 121a, 121b, and 121c, the controller 150 can determine the respective duty ratios of the pulse-width modulation signals supplied to the first switching elements S11 and S12, the second switching elements S13 and S14, and the third switching elements S15 and S16.

[0095] When the current values measured by the current sensors 121a, 121b, and 121c do not fall within a preset range, the controller 150 can determine that the current sensors 121a, 121b, and 121c that measure the corresponding current values have failed.

[0096] For example, when the first-phase current I1 measured by the first current sensor 121a does not fall within a preset range, the controller 150 can determine that the first current sensor 121a has failed.

[0097] When all the current sensors are operating normally (Yes in 1300), the controller 150 can perform pulse-width modulation control (1350) on the inverter 120 based on the average duty ratio (D) and the respective duty ratios (D1, D2, D3) determined according to the current values measured by the current sensors 121a, 121b, and 121c.

[0098] When it is determined that any one of the current sensors 121a, 121b, or 121c has failed (Yes in 1400), the controller 150 can determine the duty ratio of the pulse-width modulation signal supplied to the switching element connected to the failed current sensor based on the current measured by the non-failed current sensor.

[0099] For example, when the first current sensor 121a fails, the controller 150 can determine the duty ratio D1 of the pulse-width modulation signal supplied to the first switching elements S11 and S12 based on the average duty ratio (D) of the pulse-width modulation signal supplied to the inverter 120, the duty ratio D2 of the pulse-width modulation signal supplied to the second switching elements (S13, S14), and the duty ratio D3 of the pulse-width modulation signal supplied to the third switching elements (S15, S16) (1450).

[0100] Specifically, the controller 150 may determine the duty cycle D1 of the pulse width modulation signal supplied to the first switching elements S11 and S12 such that the average value of the duty cycle (D1) of the pulse width modulation signal supplied to the first switching elements (S11, S12), the duty cycle (D2) of the pulse width modulation signal supplied to the second switching elements (S13, S14), and the duty cycle (D3) of the pulse width modulation signal supplied to the third switching elements (S15, S16) is the average duty cycle (D) of the pulse width modulation signal supplied to the inverter 120.

[0101] That is, the controller may determine the duty cycle D1 of the pulse width modulation signal supplied to the first switching elements S11 and S12 such that the following [Equation 2] is satisfied.

[0102] [Equation 2]

[0103] D1 = 3*D - D2 - D3

[0104] Thereafter, the controller 150 may perform pulse width modulation control (1700) on the inverter 120 based on the determined respective duty cycles D1, D2, and D3.

[0105] When it is determined that two current sensors (two of the current sensors 121a, 121b, or 121c) are faulty (yes in 1500), the controller 150 may determine the duty cycle of the pulse width modulation signal supplied to the switching element connected to the faulty current sensor based on the current measured by the non-faulty current sensor.

[0106] For example, when the first current sensor 121a and the second current sensor 121b are faulty, the controller 150 may determine the duty cycle (D1) of the pulse width modulation signal supplied to the first switching elements (S11, S12) and the duty cycle (D2) of the pulse width modulation signal supplied to the second switching elements (S13, S14) based on the average duty cycle (D) of the pulse width modulation signal supplied to the inverter 120 and the duty cycle (D3) of the pulse width modulation signal supplied to the third switching elements (S15, S16).

[0107] Specifically, the controller 150 determines the duty cycle (D1) of the pulse width modulation signal supplied to the first switching elements (S11, S12) and the duty cycle (D2) of the pulse width modulation signal supplied to the second switching elements (S13, S14) such that the average value of the duty cycle (D1) of the pulse width modulation signal supplied to the first switching elements (S11, S12), the duty cycle (D2) of the pulse width modulation signal supplied to the second switching elements (S13, S14), and the duty cycle (D13) of the pulse width modulation signal supplied to the switching elements S15 and S16 is the average duty cycle (D) of the pulse width modulation signal supplied to the inverter 120.

[0108] At this time, the controller 150 can equivalently determine the duty ratio (D1) of the pulse width modulation signal provided to the first switching elements S11 and S12 and the duty ratio D2 of the pulse width modulation signal provided to the second switching elements S13 and S14.

[0109] That is, the controller can determine the duty ratio (D1) of the pulse width modulation signal provided to the first switching elements (S11, S12) and the duty ratio (D2) of the pulse width modulation signal provided to the second switching elements (S13, S14) such that the following [Equation 3] is satisfied.

[0110] [Equation 3]

[0111] D1 = D2 = (3 * D - D3) / 2

[0112] Thereafter, the controller 150 can perform pulse width modulation control (1700) on the inverter 120 based on the determined respective duty ratios D1, D2, and D3.

[0113] When it is determined that all of the current sensors 121a, 121b, and 121c have failed (No in 1500), the controller 150 can stop the charging process (1600).

[0114] For example, the controller 150 can turn on multiple relays R 1 、R 2 and R 3 in all of the relays such that the input / output port 140 is not connected to the battery 110.

[0115] That is, only when at least one of the first current sensor 121a, the second current sensor 121b, and the third current sensor 121c is operating normally, the controller 150 can perform pulse width modulation control on the inverter 120.

[0116] As described above, according to the embodiment of the present invention, if any one of the current sensors is operating normally, the convenience of the user can be achieved by performing the charging process.

[0117] However, even if a switching element fails, if it is determined that the current sensor has failed and the charging process continues because the current measured by the current sensor does not fall within a preset range, internal components of the vehicle may be damaged.

[0118] Therefore, when the temperature of any one of the first switching elements S11 and S12, the second switching elements S13 and S14, and the third switching elements S15 and S16 is higher than a preset temperature, the controller 150 can stop the charging process.

[0119] That is, only when the measured temperatures of the first switching elements S11 and S12, the second switching elements S13 and S14, and the third switching elements S15 and S16 are all below the preset temperature, can the controller 150 perform pulse width modulation control on the inverter 120.

[0120] Figure 4 is an exemplary diagram showing the pulse width modulation (PWM) signal applied to the inverter and the three-phase current changing with time according to the signal.

[0121] Reference Figure 4 , the controller 150 can perform pulse width modulation control on the inverter 120 such that the conduction periods of the pulse width modulation signals V 1 applied to the first switching elements S11 and S12, the conduction periods of the pulse width modulation signals V 2 applied to the second switching elements S13 and S14, and the conduction periods of the pulse width modulation signals V 3 applied to the third switching elements S15 and S16 are staggered.

[0122] Therefore, the fluctuations (ripple) in the sum of the first-phase current I1, the second-phase current I2, and the third-phase current I3 can be reduced, thereby improving the charging efficiency of the battery 110.

[0123] Meanwhile, some components of the vehicle 1 can be software and / or hardware components, such as field programmable gate arrays (FPGAs) and application specific integrated circuits (ASICs).

[0124] As described above, the disclosed exemplary embodiments have been described with reference to the drawings. Those skilled in the art will understand that the present invention can be implemented in a form different from the disclosed exemplary embodiments without changing the technical spirit or basic features of the present invention. The disclosed exemplary embodiments are exemplary and should not be construed as restrictive.

[0125] On the other hand, the disclosed exemplary embodiments can be implemented in the form of a recording medium for storing instructions executable by a computer. The instructions can be stored in the form of program code, and when executed by a processor, can generate program modules to perform the operations of the disclosed exemplary embodiments. The recording medium can be implemented as a computer-readable recording medium.

[0126] The computer-readable recording medium includes all types of recording media in which the instructions can be decoded by a computer. For example, the computer-readable recording medium can be a read-only memory (ROM), a random access memory (RAM), magnetic tape, magnetic disk, flash memory, an optical data storage device, etc.

[0127] As described above, the disclosed exemplary embodiments have been described with reference to the accompanying drawings. Although the exemplary embodiments of the present invention have been shown and described, those skilled in the art can understand that these embodiments can be modified without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the claims and their equivalents.

[0128] According to the present invention, when charging a battery, even if the current sensor for measuring the three-phase current fails, charging can be continued by using the current sensor that has not failed, thereby achieving user convenience.

Claims

1. A vehicle, comprising: an electric motor, which comprises: a neutral node configured to receive a charging voltage from a charging device; a first winding, a second winding, and a third winding connected to the neutral node; an inverter configured to boost the charging voltage and comprising: a first switching element connected to the first winding; a second switching element connected to the second winding; a third switching element connected to the third winding; a battery configured to receive the boosted charging voltage; a first current sensor configured to measure a first phase current flowing through the first winding; a second current sensor configured to measure a second phase current flowing through the second winding; a third current sensor configured to measure a third phase current flowing through the third winding; and a controller configured to: determine an average duty ratio of a pulse width modulation signal provided to the inverter based on the charging voltage and a battery voltage of the battery; determine a duty ratio of a pulse width modulation signal provided to each of the first switching element, the second switching element, and the third switching element based on the first phase current, the second phase current, and the third phase current; when the first current sensor fails, determine a duty ratio of a pulse width modulation signal provided to the first switching element based on the average duty ratio of the pulse width modulation signal provided to the inverter, the duty ratio of the pulse width modulation signal provided to the second switching element, and the duty ratio of the pulse width modulation signal provided to the third switching element.

2. The vehicle according to claim 1, wherein, the controller is configured to: determine a duty ratio of a pulse width modulation signal provided to the first switching element such that the average duty ratio of the pulse width modulation signal provided to the inverter is an average of the duty ratio of the pulse width modulation signal provided to the first switching element, the duty ratio of the pulse width modulation signal provided to the second switching element, and the duty ratio of the pulse width modulation signal provided to the third switching element.

3. The vehicle according to claim 1, wherein, the controller is configured to: when the first current sensor and the second current sensor fail, determine duty ratios of pulse width modulation signals provided to the first switching element and the second switching element based on the average duty ratio of the pulse width modulation signal provided to the inverter and the duty ratio of the pulse width modulation signal provided to the third switching element.

4. The vehicle according to claim 3, wherein, the controller is configured to: determine duty ratios of pulse width modulation signals provided to the first switching element and the second switching element such that the average duty ratio of the pulse width modulation signal provided to the inverter is an average of the duty ratio of the pulse width modulation signal provided to the first switching element, the duty ratio of the pulse width modulation signal provided to the second switching element, and the duty ratio of the pulse width modulation signal provided to the third switching element.

5. The vehicle according to claim 4, wherein, the controller is configured to: equally determine duty ratios of pulse width modulation signals provided to the first switching element and the second switching element.

6. The vehicle according to claim 1, wherein, the controller is configured to: perform pulse width modulation control on the inverter only when at least one of the first current sensor, the second current sensor, and the third current sensor is operating normally.

7. The vehicle according to claim 1, wherein, the vehicle further comprises: a temperature sensor configured to measure the temperature of each first switching element, each second switching element, and each third switching element, wherein the controller is configured to perform pulse width modulation control on the inverter only when the temperature measured by the temperature sensor is lower than a preset temperature.

8. The vehicle according to claim 1, wherein, the controller is configured to: perform pulse width modulation control on the inverter such that the conduction periods of the pulse width modulation signals provided to the first switching element, the conduction periods of the pulse width modulation signals provided to the second switching element, and the conduction periods of the pulse width modulation signals provided to the third switching element are staggered.

9. The vehicle according to claim 1, wherein, the vehicle further comprises: an input / output port connected to a charging device; a first relay connected between the upper switching element of the inverter and the input / output port; a second relay connected between the neutral node and the input / output port; and a third relay connected between the lower switching element of the inverter and the input / output port; wherein the controller is configured to: when the charging voltage provided from the charging device is less than the battery voltage of the battery, close the second relay and the third relay and open the first relay.

10. The vehicle according to claim 9, wherein, the controller is configured to: when the charging voltage provided from the charging device is greater than or equal to the battery voltage of the battery, close the first relay and the third relay and open the second relay.

11. A control method for a vehicle, the method comprises: receiving a charging voltage from a charging device through the neutral node of the motor; boosting the charging voltage by an inverter connected to the motor; receiving the boosted charging voltage; measuring a first phase current flowing through a first winding of the motor by a first current sensor; measuring a second phase current flowing through a second winding of the motor by a second current sensor; measuring a third phase current flowing through a third winding of the motor by a third current sensor; determining an average duty ratio of a pulse width modulation signal provided to the inverter based on the charging voltage and the battery voltage of the battery; determining a duty ratio of a pulse width modulation signal provided to each of the first switching element, the second switching element, and the third switching element based on the first phase current, the second phase current, and the third phase current; when the first current sensor fails, determining the duty ratio of the pulse width modulation signal provided to the first switching element based on the average duty ratio of the pulse width modulation signal provided to the inverter, the duty ratio of the pulse width modulation signal provided to the second switching element, and the duty ratio of the pulse width modulation signal provided to the third switching element.

12. The method according to claim 11, wherein, determining the duty ratio of the pulse width modulation signal provided to the first switching element includes: determining that the average duty ratio of the pulse width modulation signal provided to the inverter is the average of the duty ratio of the pulse width modulation signal provided to the first switching element, the duty ratio of the pulse width modulation signal provided to the second switching element, and the duty ratio of the pulse width modulation signal provided to the third switching element.

13. The method according to claim 11, wherein, The method further includes: When the first current sensor and the second current sensor fail, determining the duty cycles of the pulse width modulation signals supplied to the first switching element and the second switching element based on the average duty cycle of the pulse width modulation signal supplied to the inverter and the duty cycle of the pulse width modulation signal supplied to the third switching element.

14. The method according to claim 13, wherein, determining the duty cycles of the pulse width modulation signals supplied to the first switching element and the second switching element includes: determining that the average duty cycle of the pulse width modulation signal supplied to the inverter is the average of the duty cycle of the pulse width modulation signal supplied to the first switching element, the duty cycle of the pulse width modulation signal supplied to the second switching element, and the duty cycle of the pulse width modulation signal supplied to the third switching element.

15. The method according to claim 14, wherein, determining the duty cycles of the pulse width modulation signals supplied to the first switching element and the second switching element includes: equally determining the duty cycles of the pulse width modulation signals supplied to the first switching element and the second switching element.

16. The method according to claim 11, wherein, the method further includes: Performing pulse width modulation control on the inverter only when at least one of the first current sensor, the second current sensor, and the third current sensor is operating normally.

17. The method according to claim 11, wherein, the method further includes: Measuring the temperatures of each first switching element, each second switching element, and each third switching element; Performing pulse width modulation control on the inverter only when the temperature is lower than a preset temperature.

18. The method according to claim 11, wherein, the method further includes: Performing pulse width modulation control on the inverter such that the conduction periods of the pulse width modulation signals supplied to the first switching element, the conduction periods of the pulse width modulation signals supplied to the second switching element, and the conduction periods of the pulse width modulation signals supplied to the third switching element are staggered.

19. The method according to claim 11, wherein, the method further includes: When the charging voltage supplied from the charging device is less than the battery voltage of the battery, closing the second relay connected between the neutral node and the input / output port and the third relay connected between the lower switching element of the inverter and the input / output port, and opening the first relay connected between the upper switching element of the inverter and the input / output port.

20. The method according to claim 19, wherein, the method further includes: When the charging voltage is greater than or equal to the battery voltage of the battery, closing the first relay and the third relay and opening the second relay.

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