Multiple charging device and method

Abstract

The present invention relates to a multi-charging device and method. The multi-charging device includes: a power converter; a first sensing unit configured to sense power introduced from a motor to the power converter or to the motor; and a controller configured to determine whether the first sensing unit has failed; and, if a failure has occurred, to control charging operations of the power converter.

Description

Technical Field

[0001] The present invention relates to a high-voltage battery charging technology. Background Art

[0002] A multi-charging system is capable of charging with both a 400V-class charger and an 800V-class charger. The 800V-class charger may additionally utilize a boost converter, but operates similarly to a boost converter when utilizing a conventional motor-inverter. Therefore, the 800V-class charger utilizes a conventional motor-inverter to increase the voltage by approximately 400V to approximately 800V.

[0003] The multi-charging system using a motor and inverter operates by utilizing the motor's three-phase windings, the inverter's six switches, and three current sensors. Specifically, the motor and the inverter, acting as an inductor, increase the 400V voltage supplied from the electric vehicle supply equipment (EVSE) to 800V for battery charging. In other words, if the EVSE only supplies 400V, it would be difficult to charge the battery of an electric vehicle, which requires charging at 800V. Therefore, the multi-charging system addresses this situation.

[0004] However, in multiple charging systems utilizing motors and inverters, current sensors are installed for each motor phase to monitor the current drawn into or generated by the motor. If only one of the three current sensors fails, charging becomes impossible. Furthermore, if a current sensor failure causes charging to proceed through two of the three motor phases, the force balance in the motor is disrupted, causing the vehicle to move during charging, resulting in a dangerous situation.

[0005] Since only two current sensors are required for motor control to operate the vehicle, even if a current sensor fails, the vehicle can still be driven without any problems. However, since charging is not performed, the vehicle user may not end up moving to the desired location.

[0006] Therefore, there is a need for a technology that enables driving and charging even when a current sensor fails.

[0007] The contents described herein are intended to aid understanding of the background of the invention and may include contents not previously known to one skilled in the art to which the invention pertains. Summary of the Invention

[0008] The present invention provides a multi-charging device and method that can perform charging by suppressing the rotation of a motor even if some sensors fail.

[0009] Furthermore, the present invention also provides a multi-charging apparatus and method that enables charging operation even if one of the three sensors is removed by increasing control accuracy.

[0010] To achieve these objects, the present invention provides a multi-charging device that can perform charging by suppressing the rotation of a motor even if some sensors malfunction.

[0011] The multi-charging device is characterized by comprising:

[0012] a power converter for converting first voltage power introduced into the motor into second voltage power greater than the first voltage power, so as to supply the second voltage power to the battery;

[0013] a first sensing unit provided at each of the three phases of the motor to sense power of each phase of the first voltage power; and

[0014] A controller is configured to determine whether the first sensing unit fails and, based on the determination result, perform charging operation control on the power converter when a fault occurs to control a current value of the faulty phase based on a current value of a normal phase among three phases.

[0015] Furthermore, the controller is characterized by determining whether a fault occurs by comparing an output value of the first sensing unit with a preset reference value.

[0016] Different from the above case, the controller is characterized in that: whether a fault occurs is determined by whether the on / off timing of at least one power switching element provided in the power converter is consistent with the change timing of the output value of the first sensing unit.

[0017] Furthermore, the charging operation control is characterized by including a first control that performs control using a default value calculated based on a faulty phase and a second control that performs normal control based on a normal phase.

[0018] Furthermore, the default value is characterized by being calculated by using a control duty ratio value of a faulty phase in which a fault occurs.

[0019] Furthermore, the control duty value is characterized by being calculated by dividing a difference between the battery power value and the external charging device power value by the battery power value.

[0020] Furthermore, the control duty value is characterized in that the first adjustment is performed when the output value of the faulty phase and the output value of the normal phase are not equal to each other.

[0021] In addition, the first adjustment is characterized in that when the output value of the faulty phase is greater than the output value of the normal phase, the control duty cycle value is reduced, and when the output value of the faulty phase is less than the output value of the normal phase, the control duty cycle value is increased.

[0022] Furthermore, the control duty value is characterized in that when the output value of the faulty phase and the output value of the normal phase are equal to each other, the second adjustment is performed according to whether the motor is rotating as sensed by the second sensing unit.

[0023] In addition, the second adjustment is characterized in that: when the position value of the second sensing unit that moves as the motor rotates is greater than the current value of the second sensing unit before charging starts, the control duty cycle value is reduced; when the position value of the second sensing unit is less than the current value, the control duty cycle value is increased to prevent the motor from rotating.

[0024] On the other hand, another exemplary embodiment of the present invention provides a multiple charging method, which includes: sensing the power of each phase of a first voltage introduced from the motor by a first sensing unit provided in each of the three phases of the motor; determining by a controller whether a fault occurs in the first sensing unit; based on the determination result, when a fault occurs, performing charging operation control by the controller, wherein the charging operation control controls the current value of the faulty phase based on the current value of a normal phase among the three phases; and charging by a power converter, wherein the power converter converts the first voltage power into a second voltage power greater than the first voltage power to supply the second voltage power to a battery.

[0025] Even if part of the sensors malfunctions, the present invention can perform charging by preventing the motor from rotating.

[0026] Furthermore, the present invention may eventually remove one of the current three sensors as the accuracy of the control is increased.

[0027] In addition, the present invention can also save design costs by removing some components. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a block diagram showing a configuration of a multi-charging device according to one embodiment of the present invention.

[0029] Figure 2 To show Figure 1 The block diagram of the specific configuration of the multi-charging device is shown.

[0030] Figure 3 To show Figure 1 The block diagram of the specific configuration of the controller is shown.

[0031] Figure 4FIG. 1 is a flowchart illustrating a multi-charge control process according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] Various changes and exemplary embodiments can be made in the present invention, so that specific exemplary embodiments are shown in the drawings and described in detail in the specification. However, it should be understood that the exemplary embodiments are not intended to limit the present invention to the specific disclosed forms, but rather the present invention includes all modifications, equivalent forms and alternative forms that fall within the spirit and technical scope of the present invention.

[0033] When describing each figure, similar reference numerals are used for similar components. The terms "first," "second," etc. may be used to describe various components, but these components should not be limited by these terms. These terms are only used to distinguish one element from another.

[0034] For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component. The term "and / or" includes a combination of multiple related listed items or any one of the multiple related listed items.

[0035] Unless otherwise defined, all terms used herein including technical or scientific terms have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0036] Unless expressly defined in this application, terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the relevant technology and should not be interpreted as an ideal or overly formal meaning.

[0037] Hereinafter, a multi-charging device and method according to exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0038] Figure 1 FIG. 1 is a block diagram illustrating a configuration of a multi-charging device 100 according to some embodiments of the present invention. Figure 1 The multi-charging device 100 is characterized by including sensing units 110 and 120, a controller 130, a power converter 140, an external charging device 150, a battery 160, and the like.

[0039] The sensing units 110 and 120 are composed of a first sensing unit 110 and a second sensing unit 120. The first sensing unit 110 is used to sense the power input to the power converter 140 or the power output from the power converter 140 to the motor (not shown). To this end, the first sensing unit 110 can be composed of a current sensor, a voltage sensor, etc. In addition, as the current sensor, a Hall sensor, a fiber optic current sensor, a current transformer (CT) type current sensor, etc. can be used.

[0040] The second sensing unit 120 is used to sense the rotation of the motor. To this end, the second sensing unit 120 can be composed of a rotary transformer, an encoder, etc.

[0041] The controller 130 is used to determine a failure of the first sensing unit 110 , and when the failure occurs, performs charging operation control on the power converter 140 with reference to output values ​​of the sensing units 110 , 120 , an output value of the battery, etc.

[0042] Power converter 140 is used to convert lower DC power into higher DC power. That is, power converter 140 converts 400V DC power supplied from external charging device 150 into 800V DC power to supply 800V DC power to battery 160. In this case, battery 160 can be charged only by 800V DC power.

[0043] Of course, the power converter 140 is also used to convert DC power output from the battery 160 into AC power to supply the AC power to a motor (not shown).

[0044] To this end, power converter 140 is configured to include an inverter. Thus, power converter 140 can operate similarly to a boost converter utilizing a motor-inverter structure. That is, power converter 140 becomes a three-phase alternating boost converter. A boost converter is used to increase the voltage from approximately 400V to 800V.

[0045] Generally, the multi-charging system is a system that uses an external charging device 150 of about 400V class to help charge the battery 160 of 800V class.

[0046] The external charging device 150 is used to supply only DC power of 400 V. The external charging device 150 may be electric vehicle supply equipment (EVSE) for a vehicle or the like.

[0047] Battery 160 is a dedicated 800V-class battery. It includes battery cells connected in series and / or in parallel, and may be a high-voltage battery for electric vehicles, such as a nickel metal ion battery, a lithium-ion battery, or a lithium polymer battery. Generally, a high-voltage battery refers to a battery with a voltage of 100V or higher, used as a power source for electric vehicles.

[0048] The battery cell can be designed as a cylindrical cell, a prismatic cell, a pouch-type cell, etc. The pouch-type cell includes a flexible cover body made of a film, and the electrical components of the battery cell are arranged in the cover body.

[0049] To achieve optimal space utilization within a battery cell, pouch-type cells are typically used. Pouch-type cells are also characterized by their high capacity and low weight. The edges of these pouch-type cells include a sealing joint (not shown). This joint connects the two membranes of the battery cell, and the membranes contain additional components within the cavity formed by this connection.

[0050] Typically, the pouch cell may further include an electrolyte solution, such as a lithium secondary battery or a nickel-metal hydride battery. The battery 160 may include a battery management system (BMS) that checks a battery state and manages the battery.

[0051] Figure 2 To show Figure 1 The block diagram of the specific configuration of the multi-charging device 100 is shown. Figure 2 , the motor 20 utilizes a three-phase AC motor.

[0052] The first sensing unit 110 is disposed between the motor 20 and the power converter 140. The first sensing unit 110 is composed of first to third sensors 211, 212, and 213 to sense each of the three phases. Figure 2 In FIG, it is assumed that the first sensor 211 is in a fault state. Therefore, the output value of the first phase of the three phases is zero, and the output value of the second phase and the output value 202 of the third phase of the three phases are generated by the second sensor 212 and the third sensor 213 respectively.

[0053] Controller 130 determines whether a sensor failure has occurred by using output values ​​202 of the first to third phases generated by first to third sensors 211, 212, and 213. If a failure is determined, controller 130 divides power converter 140 into two sections and performs second control 204 (normal control) on a normal section 241 connected to the normal sensors. Separately, controller 130 performs first control 203, which uses a basic value based on correction, on a faulty section 242 connected to the faulty sensor.

[0054] The power converter 140 has a pair of power switching elements 241-1 provided for each phase, and the first to third sensors 211, 212, and 213 can be connected to the neutral point of the pair of power switching elements 241-1. As the power switching element 241-1, the following semiconductor switching elements can be used: for example, a field effect transistor (FET), a metal oxide semiconductor FET (MOSFET), an insulated gate bipolar mode transistor (IGBT), or a power rectifier diode, a thyristor, a gate turn-off (GTO) thyristor, an alternating current transistor (TRIAC), a silicon controlled rectifier (SCR), an integrated circuit (IC) type circuit, etc. Specifically, in the case of semiconductor elements, bipolar elements, power metal oxide silicon field effect transistor (MOSFET) elements, etc. can be used. Due to high voltage and high current operation, unlike general MOSFETs, power MOSFET elements have a double-diffused metal oxide semiconductor (DMOS) structure.

[0055] Power converter 140 utilizes a pulse width modulation (PWM) inverter. A PWM inverter is a voltage-type inverter, but is not limited thereto and may also utilize a current-type inverter by modifying some components. A PWM inverter utilizes a pulse width modulation (PWM) control method to simultaneously control the voltage and frequency of the rectified DC voltage.

[0056] In addition, the motor 20 is provided with a three-phase winding and a second sensing unit 120 is provided to sense the rotation of the motor 20. Therefore, when the second sensing unit 120 senses the rotation of the motor 20, a sensing signal 201 is transmitted to the controller 130. In this case, the controller 130 adjusts the motor to prevent the motor from running, thereby preventing the motor 20 from rotating.

[0057] The switching elements 261-1 and 261-2 are provided at the front end of the battery 160 to electrically conduct or cut off the power output from the battery 160. Of course, the switching elements 261-1 and 261-2 are also used to electrically conduct or cut off the power input to the battery 160.

[0058] Furthermore, switching elements 263-1 and 263-2 are also provided at the output end of the external charging device 150 to electrically conduct or cut off the power output from the external charging device 150. Of course, a switching element 264 may also be provided between the motor 20 and the external charging device 150 to cut off or conduct the power introduced into the motor 20.

[0059] Power relays are used as switching elements 261-1, 261-2, 263-1, 263-2, and 264, but the present invention is not limited thereto, and the following semiconductor switching elements may be used: for example, field effect transistors (FETs), metal oxide semiconductor FETs (MOSFETs), insulated gate bipolar transistors (IGBTs), or power rectifier diodes, thyristors, gate turn-off (GTO) thyristors, alternating current triodes (TRIACs), silicon controlled rectifiers (SCRs), integrated circuit (IC) type circuits, etc. Specifically, in the case of semiconductor elements, bipolar elements, power metal oxide silicon field effect transistor (MOSFET) elements, etc. may be used. Due to high voltage and high current operation, unlike general MOSFETs, power MOSFET elements have a double-diffused metal oxide semiconductor (DMOS) structure.

[0060] First capacitor 271 is provided at the front end of power converter 140 to constantly maintain the output power of power converter 140. Second capacitor 272 is connected to external charging device 150 and the ground line to constantly maintain the power introduced into motor 20.

[0061] Further references Figure 2 , an external charging device output value 207 from the external charging device 150 is used as an input value 208 for the motor 20, and generates charging power 206 while passing through the power converter 140. The external charging device output value 207 is approximately 400 V, and the charging power 206 is changed to approximately 800 V by a boost converter composed of the inductance component of the motor 20 and the power switching element 241-1 of the power converter 140.

[0062] Additionally, the controller 130 receives a battery output value 205 from the battery 160 .

[0063] Figure 3 To show Figure 1 The block diagram of the specific configuration of the controller 130 is shown in FIG. Figure 3 The controller 130 may be configured to include a determination module 310 , a calculation module 320 , an adjustment module 330 , and the like.

[0064] The determination module 310 is used to determine whether the sensing unit 110 has failed by using the output value sensed by the sensing unit 110. The calculation module 320 calculates the control duty cycle value (D) of the motor phase (ie, the corresponding phase) that has failed. This is expressed as follows by Equation 1.

[0065] Equation 1

[0066]

[0067] Among them, V in represents the external charging device power value of the external charging device 150, V out Indicates the battery power value of the battery 160. For example, when V in =400V and V out When =800V, D=0.5.

[0068] Adjustment module 330 controls the on / off switching of power switching element 241-1 configured in power converter 140 using the control duty cycle value (D) calculated by calculation module 320. That is, adjustment module 330 performs a first control that uses a default value calculated by designating a portion of power converter 140 as a faulty portion 242. Furthermore, adjustment module 330 performs a second control that uses a normal control by designating the remaining portion of power converter 140 as a normal portion 241.

[0069] Figure 3 The determination module 310, calculation module 320 and adjustment module 330 shown represent units for processing at least one function or operation and can be implemented by software and / or hardware. In hardware implementation, the hardware can be implemented by an application specific integrated circuit (ASIC), digital signal processing (DSP), programmable logic device (PLD), field programmable gate array (FPGA), processor, microprocessor, other electronic units or a combination thereof designed to perform the above functions. In software implementation, the software can include software configuration components (elements), object-oriented software configuration components, class configuration components and work configuration components, processes, functions, attributes, processes, subroutines, program code segments, drivers, firmware, microcodes, data, databases, data structures, tables, arrangements and variables. Software, data, etc. can be stored in a memory and executed by a processor. The memory or processor can adopt various devices well known to those skilled in the art.

[0070] Figure 4 FIG is a flow chart illustrating a multi-charge control process according to some embodiments of the present invention. Figure 4First, when the external charging device 150 is plugged into the electric vehicle, the controller 130 determines whether a sensor failure occurs (steps S410 and S420). The determination of sensor failure can be confirmed by the following two situations. For ease of understanding, it is assumed that the sensor is a current sensor.

[0071] ①When the voltage value output from the current sensor is a predetermined value or above or a predetermined value or below;

[0072] ②When the power switch element ( Figure 2 When the on / off relationship of 241-1) and the change time point of the value output from the current sensor do not coincide with each other.

[0073] In the case of (2), when power switching element 241-1 is on, it corresponds to the rising portion of the AC wave, and in this case, the output value increases. Unlike the above case, when power switching element 241-1 is off, it corresponds to the falling portion of the AC wave, and in this case, the output value decreases. If the changes in the output values ​​do not match each other, controller 130 determines that the sensor has failed.

[0074] Then, when the fault of the sensor is confirmed, the controller 130 performs charging operation control for the occurrence of the fault. That is, the controller 130 calculates a default value for controlling the faulty phase (step S430, step S440).

[0075] Then, the controller 130 controls the faulty part using the calculated default value and controls the normal part through normal control (step S450). At this time, charging is started.

[0076] Then, the controller 130 compares the current of the faulty part with the current of the normal part again (step S460). That is, the current values ​​of the three phases should be substantially equal to each other. Therefore, the following relationship is established.

[0077] The current of the faulty phase (first sensor) = the current of the battery - the current of the second sensor - the current of the third sensor.

[0078] If the current values ​​of the three phases are unequal and there is a difference between them, the duty cycle should be controlled. That is, when the current value of the faulty phase is greater than the current value of the second or third phase, the duty cycle value (D) is controlled to decrease, and when the current value of the faulty phase is less than the current value of the second or third phase, the duty cycle value (D) is controlled to increase.

[0079] Basically, only when the current values ​​of the three phases are equal to each other can the balance of forces applied to the windings in the motor be maintained. When the balance of forces is broken, the motor rotates.

[0080] Due to the influence of the magnet of the rotor (not shown) configured in the motor 20 and / or the error of the current sensor, even if the current values ​​are equal to each other, the force balance may not be perfectly maintained. The controller 130 receives a sensing signal that senses the rotation of the motor 20 to determine whether the motor 20 is running (step S480). To this end, for example, the case where the second sensing unit 120 is a rotary transformer will be described. When the motor is running, the control duty cycle value (D) is finely adjusted to prevent the rotation operation of the motor (step S490).

[0081] That is, by determining the resolver position value, when the resolver position value is greater than the current value, the duty cycle value is controlled to decrease, and when the resolver position value is less than the current value, the duty cycle value is controlled to increase. Here, the resolver position value is the value obtained by the resolver moving in response to the rotation of the motor, and the current value is the value representing the position of the resolver before charging begins. In other words, the resolver consists of a resolver stator (not shown) fixed to the stator (not shown) of motor 20 and a resolver rotor (not shown) fixed to the rotor (not shown) to be rotated. Therefore, as the motor rotor rotates, the resolver rotor rotates.

[0082] In addition, the steps of the methods or algorithms described in relation to the exemplary embodiments disclosed herein may be implemented in a program instruction format that can be executed by various computer devices such as microprocessors, processors, and central processing units (CPUs), and recorded in a computer-readable medium. The computer-readable medium may include program (instruction) codes, data files, data structures, etc., either alone or in combination.

[0083] The program (instruction) code recorded in the medium may be a program (instruction) code specifically designed and configured for the present invention, or may be a program (instruction) code known and used by those skilled in the art of computer software. Examples of computer-readable recording media may include magnetic media, such as hard disks, floppy disks, and magnetic tapes; optical media, such as CD-ROMs, DVDs, and Blu-rays; and semiconductor storage elements specifically configured to store and execute program (instruction) codes, such as ROMs, RAMs, and flash memories.

[0084] Here, examples of the program (instruction) code include high-level language codes that can be executed by a computer using an interpreter, etc., and machine language codes generated by a compiler. Hardware devices can be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

Claims

1. A multi-charging device comprising: an external charging device for supplying power at a first voltage; A power converter configured as follows: converting a first voltage power introduced from the motor into a second voltage power greater than the first voltage power; supplying a second voltage power to the battery; a first sensing unit provided at each of the three phases of the motor, the first sensing unit being configured to sense power of each phase of the first voltage power; as well as The controller is configured as follows: determining whether the first sensing unit fails; When it is determined that the first sensing unit has failed, performing charging operation control on the power converter to control a current value of the faulty phase based on a current value of a normal phase among the three phases; wherein the first sensing unit is composed of first to third sensors to sense each of the three phases, and even if one of the first to third sensors fails, the charging operation control is still performed; The power converter includes a pair of power switching elements provided for each phase; and the controller is configured as follows: The control duty cycle value D for controlling the faulty phase is calculated based on the following equation 1: Equation 1 Among them, V in Indicates the external charging device power value of the external charging device, V out Indicates the battery power value of the battery; Using the calculated control duty cycle value D to control the on / off switching of a pair of power switching elements configured in the power converter; Subtract the normal phase current value from the battery current value to determine the fault phase current value; The current value of the determined faulty phase is compared with the current value of the normal phase to determine whether the forces applied to the windings within the motor are balanced.

2. The multi-charging device according to claim 1, wherein: The controller is configured as follows: Whether a fault occurs is determined by comparing the output value of the first sensing unit with a preset reference value.

3. The multi-charging device according to claim 1, wherein: The controller is configured as follows: It is determined whether a turning-on / off time point of at least one power switching element provided in the power converter is consistent with a change time point of an output value of the first sensing unit.

4. The multi-charging device according to claim 1, wherein: The controller is configured as follows: When the current value of the faulty phase is not equal to the current value of the normal phase, it is determined that the force applied to the windings in the motor is unbalanced, and the control duty cycle value D is adjusted.

5. The multi-charging device according to claim 4, wherein: The controller is configured as follows: When the current value of the fault phase is greater than the current value of the normal phase, the control duty cycle value D is reduced; When the current value of the fault phase is smaller than the current value of the normal phase, the control duty cycle value D is increased.

6. The multi-charging device according to claim 1, wherein: The controller is configured as follows: When the current value of the faulty phase is equal to the current value of the normal phase, the control duty cycle value D is adjusted based on whether the motor is rotating as sensed by the second sensing unit.

7. The multi-charging device according to claim 6, wherein: The controller is configured as follows: When the position value of the second sensing unit that moves as the motor rotates is greater than the current value of the second sensing unit before charging starts, reducing the control duty cycle value D; When the position value of the second sensing unit is smaller than the current value, the control duty cycle value D is increased to prevent the motor from rotating.

8. A multi-charging method comprising: supplying power of a first voltage from an external charging device; sensing power of each phase of a first voltage introduced from the motor by a first sensing unit provided in each of the three phases of the motor; determining, by the controller, whether a failure occurs in the first sensing unit; When it is determined that a fault has occurred, a controller executes a charging operation control that controls a current value of a fault phase based on a current value of a normal phase among three phases; charging by a power converter configured to convert first voltage power into second voltage power greater than the first voltage power to supply the second voltage power to the battery; wherein the first sensing unit is composed of first to third sensors to sense each of the three phases, and even if one of the first to third sensors fails, the charging operation control is still performed; The control duty cycle value D for controlling the fault phase is calculated by the controller based on the following equation 1: Equation 1 Among them, V in Indicates the external charging device power value of the external charging device, V out Indicates the battery power value of the battery; The controller uses the calculated control duty cycle value D to control the on / off switching of a pair of power switching elements configured in the power converter; The controller subtracts the current value of the normal phase from the current value of the battery to determine the current value of the fault phase; The controller compares the current value of the determined faulty phase with the current value of the normal phase to determine whether the forces applied to the windings in the motor are balanced.

9. The multi-charging method according to claim 8, wherein: Determining whether a fault has occurred includes: An output value of the first sensing unit is compared with a preset reference value.

10. The multi-charging method according to claim 8, wherein: Determining whether a fault has occurred includes: It is determined whether a turning-on / off time point of at least one power switching element provided in the power converter is consistent with a change time point of an output value of the first sensing unit.

11. The multi-charging method according to claim 8, further comprising: When the current value of the faulty phase is not equal to the current value of the normal phase, it is determined that the force applied to the windings in the motor is unbalanced, and the control duty cycle value D is adjusted.

12. The multi-charging method according to claim 11, wherein: Adjusting the control duty cycle value includes: When the current value of the fault phase is greater than the current values ​​of the other normal phases, the control duty cycle value D is reduced; When the current value of the fault phase is smaller than the current value of the normal phase, the control duty cycle value D is increased.

13. The multi-charging method according to claim 8, further comprising: When the current value of the faulty phase is equal to the current value of the normal phase, the control duty cycle value D is adjusted based on whether the motor is rotating as sensed by the second sensing unit.

14. The multi-charging method according to claim 13, wherein: Adjusting the control duty cycle value includes: When the position value of the second sensing unit that moves as the motor rotates is greater than the current value of the second sensing unit before charging starts, reducing the control duty cycle value D; When the position value of the second sensing unit is smaller than the current value, the control duty cycle value D is increased to prevent the motor from rotating.

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