Charging system and method using motor drive system

Abstract

To provide a charging system and method using a motor drive system for charging a vehicle battery.SOLUTION: A charging system using a motor drive system includes: an inverter 120 that includes switching elements Q11 to Q16 connected between DC connecting ends 121p, 121n and AC connecting ends (motor connection ends 121a - 121c) and adjusts the on / off state of a switching element to perform power conversion between the DC connecting ends and the AC connecting ends; a motor 130 including a plurality of coils connected to the AC connecting ends; first relays R11, R12 one end of each of which is connected to the DC connecting ends and the other end of each of which is connected to a charging power input terminal, and a second relay R13 one end of which is connected to a neutral point of the motor and the other end of which is connected to the charging power input terminal; and a controller 150 that, based on a result of comparing a voltage detection value of a battery 110 with a maximum value of a charging voltage provided for the charging power input terminal by charging equipment, controls states of the first relays and second relay to provide the battery with charging power from the charging equipment.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a charging system and method using a motor-driven system, and more particularly, to a charging system and method using a motor-driven system capable of charging a vehicle battery using charging equipment of various voltages by utilizing a motor-driven system installed in a vehicle, and further improving charging efficiency depending on the state of the vehicle battery. [Background technology]

[0002] In general, an electric vehicle or a plug-in hybrid vehicle can generate power for the vehicle by receiving power provided from an external charging facility to charge a battery inside the vehicle and driving a motor with the electric energy stored in the charged battery.

[0003] There are two main methods for charging the battery in a vehicle: a slow charging method, which receives external AC charging power and converts it into DC charging power suitable for charging the battery, and charges the battery at a relatively slow speed using an on-board charger; and a fast charging method, which provides external DC charging power directly to the battery to charge it quickly.

[0004] In the case of a quick charging method, if the charging equipment cannot provide a voltage large enough to charge the vehicle battery, charging may not be possible. For example, a charging equipment for quick charging is manufactured to output a single voltage standard of 400V, but the battery used in the vehicle may be designed to have a voltage of 800V or more to improve efficiency and driving distance. In this case, the quick charging equipment still provides a charging voltage of 400V, but the battery used in the vehicle has a voltage specification of 800V or more. Therefore, the quick charging equipment cannot be directly connected to the vehicle to charge the battery, and a separate boost converter is required to boost the voltage provided from the external charging equipment for charging.

[0005] However, a large-capacity boost converter for boosting a voltage of 400V to 800V or more is not only very heavy and bulky, but also expensive, making it difficult to install in a vehicle. Even if it is installed in the vehicle, it can cause a significant increase in the price of the vehicle.

[0006] Therefore, in this technical field, a new charging technology has been proposed that can receive the voltage of a charging equipment that provides a relatively low charging voltage constructed as an existing infrastructure, boost it to a high voltage without additional equipment or additional costs, and provide it to a battery. The new technology converts the external charging power received at the neutral point of a motor using an inverter and then provides it to the battery to charge the battery (Korean Patent Publication No. 10-2019-0119778).

[0007] The charging technique using a motor drive system that has already been proposed uses a method in which the connection structure between the three-phase coils in the motor and the switching elements of the inverter is controlled to become a converter, boosting the charging voltage input to the neutral point where the three-phase coils are connected to each other and applying it to the battery connected to the inverter.

[0008] A charging technique using such a conventional motor drive system simply applies a DC voltage provided from a charging device directly to the battery according to the voltage specifications of the battery, or receives a DC voltage at the neutral point of the motor, boosts it using the motor drive system, and provides it to the battery by selecting one of two modes.

[0009] However, since the conventional method does not determine the charging method based on the actual voltage of the battery, even in a situation where a DC voltage can be directly applied to the battery, the battery may be charged through a voltage conversion process of the motor driving system, which may result in problems of reduced efficiency and increased charging time due to switching loss or reduced charging power. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Korean Patent Publication No. 10-2019-0119778 Summary of the Invention [Problem to be solved by the invention]

[0011] Therefore, a technical objective of the present invention is to provide a charging system and method using a motor-driven system that can charge a vehicle battery using charging equipment of various voltages by utilizing a motor-driven system installed in a vehicle, and can further improve charging efficiency by selectively determining a charging method according to an actual voltage state of the vehicle battery. [Means for solving the problem]

[0012] As a means for solving the technical problems, the present invention provides a charging system using a motor driving system, including: an inverter including a switching element connected between a DC connection end to which a battery is connected and an AC connection end, and performing power conversion between the DC connection end and the AC connection end by adjusting an on / off state of the switching element; a motor including a plurality of coils connected to the AC connection end; a first relay having one end connected to the DC connection end and the other end connected to a charging power input end, and a second relay having one end connected to a neutral point of the motor and the other end connected to the charging power input end; and a controller controlling states of the first and second relays based on a result of comparing a voltage detection value of the battery and a maximum value of a charging voltage provided by a charging equipment to the charging power input end, to provide the battery with charging power provided from the charging equipment.

[0013] In an embodiment of the present invention, the controller may determine one of a first charging mode in which the charging power is directly applied to the DC connection terminal by shorting the first relay and opening the second relay to charge the battery, and a second charging mode in which the charging power is applied to the neutral point of the motor by opening the first relay and shorting the second relay, and the charging power applied to the neutral point of the motor is converted in voltage magnitude by controlling an on / off state of the switching element and outputted to the DC connection terminal to charge the battery.

[0014] In one embodiment of the present invention, the controller may charge the battery in the first charging mode when a detected voltage value of the battery is lower than the maximum charging voltage.

[0015] In one embodiment of the present invention, the controller calculates a remaining charging time required for the battery to be charged to a charging state corresponding to the maximum charging voltage, and charges the battery in the first charging mode if the remaining charging time is greater than a preset reference time, and charges the battery in the second charging mode if the remaining charging time is equal to or less than the reference time.

[0016] In one embodiment of the present invention, the controller may determine one of the first charging mode and the second charging mode by applying a voltage detection value of the battery and a charging current provided by the charging equipment to a charging mode determination table according to a relationship between a voltage or a charging state of the battery and a charging current provided by the charging equipment.

[0017] In one embodiment of the present invention, the charging mode determination table may be determined to perform the first charging mode when the battery voltage or charging state is low and the charging current is low, and to perform the second charging mode when the battery voltage or charging state is high and the charging current is high.

[0018] In one embodiment of the present invention, the controller may change the charging method to the second charging mode when, while performing the first charging mode, the voltage detection value of the battery becomes equal to or greater than the maximum charging voltage, or when the charging state corresponding to the voltage detection value of the battery becomes equal to or greater than the charging state corresponding to the maximum charging voltage.

[0019] In one embodiment of the present invention, the controller provides a charging current command of 0 to the charging equipment when the voltage detection value of the battery becomes equal to or greater than the maximum charging voltage or when the charging state corresponding to the voltage detection value of the battery becomes equal to or greater than the charging state corresponding to the maximum charging voltage while performing the first charging mode, and then opens the first relay and shorts the second relay when the current provided from the charging equipment becomes substantially 0, and then increases the charging current command.

[0020] As another means for solving the above technical problem, the present invention provides a charging method using a motor driving system including: an inverter including a switching element connected between a DC connection end to which a battery is connected and an AC connection end, and performing power conversion between the DC connection end and the AC connection end by adjusting an on / off state of the switching element; a motor including a plurality of coils connected to the AC connection end; a first relay having one end connected to the DC connection end and the other end connected to a charging power input end; and a second relay having one end connected to a neutral point of the motor and the other end connected to the charging power input end, and comparing a maximum value of a charging voltage provided by a charging equipment to the charging power input terminal with the detected voltage of the battery, or comparing a charging state of the battery corresponding to a voltage detection value of the battery with a charging state corresponding to the maximum charging voltage; and, when the voltage detection value of the battery is lower than the maximum charging voltage or the charging state of the battery corresponding to the voltage detection value of the battery is lower than a charging state corresponding to the maximum charging voltage, shorting the first relay and opening the second relay to perform a first charging mode in which charging power is directly applied to the DC connection terminal to charge the battery.

[0021] In an embodiment of the present invention, when a voltage detection value of the battery is equal to or greater than the maximum charging voltage, or when a charging state of the battery corresponding to the voltage detection value of the battery is equal to or greater than a charging state corresponding to the maximum charging voltage, the first relay is opened and the second relay is shorted to apply the charging power to a neutral point of the motor, and the on / off state of the switching element is controlled to convert the voltage magnitude of the charging power applied to the neutral point of the motor and output it to the DC connection terminal, thereby performing a second charging mode in which the battery is charged.

[0022] In an embodiment of the present invention, the method may further include calculating a remaining charging time required for the battery to be charged to a charging state corresponding to a maximum charging voltage, performing the first charging mode when the remaining charging time is greater than a preset reference time, and performing a second charging mode in which the charging power is applied to a neutral point of the motor by opening the first relay and shorting the second relay when the remaining charging time is equal to or less than the reference time, and controlling an on / off state of the switching element to convert a voltage magnitude of the charging power applied to the neutral point of the motor and output the converted voltage to the DC connection terminal to charge the battery.

[0023] In an embodiment of the present invention, the method may further include determining one of the first charging mode and the second charging mode by applying a voltage detection value of the battery and a charging current provided by the charging equipment to a charging mode determination table according to a relationship between a voltage or a charging state of the battery and a charging current provided by the charging equipment.

[0024] In one embodiment of the present invention, the charging mode determination table may be determined to perform the first charging mode when the battery voltage or charging state is low and the charging current is low, and to perform the second charging mode when the battery voltage or charging state is high and the charging current is high.

[0025] In an embodiment of the present invention, the method may further include changing a charging method to a second charging mode in which, when a voltage detection value of the battery becomes equal to or greater than the maximum charging voltage, or a charging state corresponding to the voltage detection value of the battery becomes equal to or greater than the charging state corresponding to the maximum charging voltage, the first relay is opened and the second relay is shorted to apply the charging power to a neutral point of the motor, and the charging power applied to the neutral point of the motor is converted in voltage magnitude by controlling an on / off state of the switching element and outputted to the DC connection terminal to charge the battery.

[0026] In one embodiment of the present invention, the method may further include providing a charging current command of 0 to the charging equipment when a voltage detection value of the battery becomes equal to or greater than the maximum charging voltage or a charging state corresponding to the voltage detection value of the battery becomes equal to or greater than a charging state corresponding to the maximum charging voltage while performing the first charging mode, and then opening the first relay and shorting the second relay when a current provided from the charging equipment becomes substantially 0. Effect of the Invention

[0027] According to the charging system and method using the motor-driven system of the present invention, even if the battery specifications are higher than the maximum charging voltage provided by the external charging equipment, if the actually measured battery voltage (i.e., the battery voltage detection value) is lower than the maximum charging voltage provided by the charging equipment, the charging power provided by the external charging equipment is directly applied to the battery without converting the voltage magnitude, thereby reducing the battery charging time and improving charging efficiency. The effects obtained by the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those having ordinary skill in the art to which the present invention pertains from the following description. [Brief description of the drawings]

[0028] [Figure 1] 1 is a configuration diagram of a charging system using a motor drive system according to an embodiment of the present invention. [Diagram 2] 4 is a flowchart of a charging method using a motor drive system according to an embodiment of the present invention. [Diagram 3] FIG. 10 is a diagram for explaining the concept of a charging mode determination table applied to a charging system and method using a motor drive system according to an embodiment of the present invention. [Figure 4] 4 is a flowchart illustrating in more detail a charging mode switching step in a charging system and method using a motor drive system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Hereinafter, a charging system and method using a motor drive system according to various embodiments will be described in detail with reference to the accompanying drawings.

[0030] FIG. 1 is a configuration diagram of a charging system using a motor drive system according to an embodiment of the present invention. Referring to FIG. 1, a charging system according to an embodiment of the present invention may include a battery 110, an inverter 120, a motor 130, a plurality of relays R11, R12, R13, and a controller 150 provided in a vehicle.

[0031] In general, a system for driving the motor 130 may include a battery 110, which is an energy storage device that stores power for driving the motor 130, and an inverter 120 that converts the DC power stored in the battery 110 into three-phase AC power and provides it to the motor 130. The inverter 120 has a DC connection terminal including a positive (+) terminal 121p and a negative (-) terminal 121n that are respectively connected to both ends of the battery 110, and three legs connected in parallel between the DC connection terminals, and two switching elements Q11 and Q12, Q13 and Q14, and Q15 and Q16 are connected in series to each other in each leg, and connection nodes of the two switching elements become a plurality of motor connection terminals 121a, 121b, and 121c that are respectively connected to each phase of the motor 130.

[0032] In order to drive the motor, pulse width modulation control of the switching elements Q11 to Q16 in the inverter 120 can be performed so that a current corresponding to a current command corresponding to the torque of the motor 130 to be obtained by driving the motor 130 can be provided to the motor 130. In this manner, the flow of energy for driving the motor 130 is from the battery 110 in FIG. 1 to the motor 130.

[0033] On the other hand, when power is fed from the neutral point of the motor 130 to the DC connection terminals 121p and 121n of the inverter 120, two switching elements Q11 and Q12, or Q13 and Q14, or Q15 and Q16 included in one leg of the inverter 120, and a coil in the motor 130 having one end connected to the connection node of the two switching elements can form a DC converter circuit that can boost the neutral point voltage and provide it to the DC connection terminal of the inverter.

[0034] Therefore, the connection structure of the coils in the inverter 120 and the motor 130 is like a total of three converter circuits connected in parallel, and by controlling the switching elements Q11 to Q16 to operate these multiple parallel-connected DC converters simultaneously or selectively, or in an interleaved manner, the voltage of the neutral point N can be boosted and provided to the battery 110.

[0035] Some embodiments of the present invention may be embodied to selectively use a first charging mode in which the external charging power is directly provided to the battery 110 based on the magnitude of the maximum voltage of the external charging power provided from an external charging device (e.g., Electric Vehicle Supply Equipment (EVSE)) 200 to the vehicle's charging input / output port 140 and the current voltage of the battery (i.e., the voltage detection value), and a second charging mode in which the external charging power is provided to the neutral point N of the motor 130 and then boosted by controlling the switching elements Q11 to Q16 of the inverter 120 and provided to the battery 110.

[0036] The controller 150 may generally have a structure including a memory in which algorithms or instructions for performing calculations or decisions are stored, and a processor for performing decisions and decisions by executing the algorithms or instructions stored in the memory. In some embodiments of the present invention, the controller 150 may determine whether to select the first charging mode and the second charging mode, or to switch from the first charging mode to the second charging mode. The controller 150 may be embodied in the form of a vehicle controller, a motor controller, or a battery management system that is already provided in a vehicle, or may be additionally provided in a vehicle.

[0037] The operation and effects of the controller 150 will be more clearly understood from the description of a charging method using a motor drive system according to an embodiment of the present invention described below.

[0038] FIG. 2 is a flowchart of a charging method using a motor drive system according to an embodiment of the present invention. Referring to FIG. 2, when an external charging device 200 is electrically connected to the vehicle charging input / output port 140 and a charging process is started, the controller 150 detects the voltage of the battery 110 in the vehicle and outputs a voltage detection value V BAT and the maximum charging voltage V of the charging power provided by the charging equipment 200 EVSE、max Then, the two values ​​can be compared (S11).

[0039] Then, the controller 150 may selectively perform step S12 to determine the charging mode. Step S12 is for determining whether performing the first charging mode has a substantial effect, i.e., a substantial effect that can reduce the charging time.

[0040] In step S12, the battery 110 is charged at a maximum voltage V EVSE、maxThe remaining charging time required to charge the battery to a State Of Charge (SOC) corresponding to the battery voltage can be calculated, and the remaining charging time can be compared with a preset reference time. Generally, the voltage of a battery changes depending on the SOC. For example, if the SOC of a battery is high, the voltage of the battery will be high, and if the SOC of a battery is low, the voltage of the battery will be low. Therefore, the SOC of the battery can be determined based on the voltage of the battery.

[0041] As described above, the first charging mode is a mode in which DC charging power is directly provided to the battery 110 without a conversion process, and the second charging mode is a mode in which the magnitude of the voltage is converted by switching the switching elements of the boost converter circuit implemented by the motor 130 and the inverter 120, and charging power is provided to the battery 110. The first charging mode is performed when the voltage detection value of the battery 110 is lower than the maximum charging voltage of the charging device 200, and when the voltage detection value of the battery 110 becomes higher than the maximum charging voltage due to charging, the charging mode must be switched to the second charging mode.

[0042] As described below, in order to change the state of relays R11 and R12 to switch the charging mode, the charging current provided by the charging device 200 must be substantially reduced to 0, and in order to resume charging, the charging current must be increased to a desired value, but a certain amount of time is required for the charging current to be reduced and increased. In other words, a certain amount of time is required to switch the charging mode and charge continuously. Therefore, if the time required to switch the charging mode is longer than the charging time that can be reduced by applying the first charging mode, the voltage detection value V of the battery 110 BAT is the maximum charging voltage V EVSE、max Even if the difference is smaller, it is more preferable to apply the second charging mode from the start of charging without applying the first charging mode.

[0043] In consideration of this, in step S12, the controller 150 determines whether the battery 110 is charged at a maximum charging voltage VEVSE、max The remaining charging time required to charge to a State Of Charge (SOC) corresponding to the battery is calculated, the remaining charging time is compared with a preset reference time, and if the remaining charging time is greater, the first charging mode is executed (S13), otherwise, the second charging mode is executed (S15). Here, the reference time may correspond to the time required to switch the charging mode.

[0044] As another example, in step S12, it may be determined whether or not to execute the first charging mode depending on the SOC of the battery 110 and the magnitude of the charging current provided by the charging device 200.

[0045] When the SOC of the battery 110 is low, the charging time in the first charging mode is long, so the effect of applying the first charging mode is large. In addition, if the magnitude of the charging current provided by the charging device 200 is sufficiently large, the first charging mode is not executed, and only the second charging mode is executed, so that the maximum charging voltage V of the charging device 200 can be increased without switching the charging mode. EVSE、max It may be more efficient to fully charge the battery to a higher voltage.

[0046] FIG. 3 is a diagram for explaining the concept of a charging mode determination table applied to a charging system and method using a motor drive system according to an embodiment of the present invention.

[0047] As shown in FIG. 3, the controller 150 stores a table in advance in which it is determined whether the first charging mode and the second charging mode are to be executed depending on the relationship between the SOC of the battery 110 and the charging current, and can use this to determine whether the first charging mode and the second charging mode are to be executed.

[0048] The controller 150 may determine the charging mode by performing step S11 and then step S12, or may determine the charging mode by performing only one of steps S11 and S12.

[0049] If it is determined as a result of the judgment in step (S11) and / or step (S12) that the first charging mode is to be executed, the controller 150 shorts the first relay R11 and the third relay R13 and opens the second relay R12, thereby providing the charging power provided to the charging input / output port 140 directly to the battery 110 without a conversion process, thereby charging the battery 110 (S13).

[0050] Next, while performing the first charging mode (S13), the controller 150 detects the voltage V BAT is the maximum charging voltage V EVSE、max or the voltage detection value V of the battery 110 BAT The SOC corresponding to the maximum charging voltage V EVSE、max When the SOC reaches or exceeds the SOC corresponding to the first charging mode (S14), the first relay R11 is opened and the second relay R12 and the third relay R13 are shorted, thereby changing the charging method from the first charging mode to the second charging mode (S15).

[0051] The controller 150 may then determine to end the charging process when the SOC of the battery 110 reaches a preset target value or the battery 110 is fully charged (S16).

[0052] In the step of switching the charging mode (S14), the controller 150 transmits a charging current command to the external charging device 200 and controls the states of the relays R11 and R12 while adjusting the magnitude of the charging current provided from the charging device 200.

[0053] FIG. 4 is a flowchart illustrating in more detail the charging mode switching step in the charging system and method using a motor drive system according to an embodiment of the present invention. Referring to FIG. 4, the controller 150 detects the battery voltage V while performing the first charging mode. BAT is the maximum charging voltage V EVSE、max The battery voltage detection value V BAT The charge state corresponding to the maximum charge voltage VEVSE、max If the charging state of the battery reaches or exceeds the charging state corresponding to the charging device 200, a charging current command of 0 is provided to the charging device 200 (S141). After confirming that the current provided from the charging device 200 has become substantially 0 (S142), the first relay R11 is opened and the second relay R12 is shorted, thereby configuring a circuit structure to perform a second charging mode in which charging is performed by voltage magnitude conversion by the motor 130 and the inverter 120 (S143). Then, a current command is increased and provided to the charging device 200, so that a current of a desired magnitude can be provided from the charging device 200.

[0054] As described above, the charging system and method using a motor-driven system according to some embodiments of the present invention can reduce battery charging time and improve charging efficiency by directly applying charging power provided from an external charging equipment to the battery without converting the voltage magnitude when the battery specifications are greater than the maximum charging voltage provided by the external charging equipment and the actually measured battery voltage (i.e., the battery voltage detection value) is less than the maximum charging voltage provided by the charging equipment.

[0055] While particular embodiments of the present invention have been shown and described, it will be obvious to those of ordinary skill in the art that various modifications and variations of the present invention are possible, all of which are within the scope of the appended claims. [Explanation of symbols]

[0056] 110 Battery 120 Inverter 121p, 121n DC connection end 121a, 121b, 121c Motor connection end 130 Motor 140 External connection port 150 Controller 200 Charging equipment N Motor neutral point Q11, Q12, Q13, Q14, Q15, Q16 Inverter switching elements R11, R12, R13 Relays

Claims

1. an inverter including a switching element connected between a DC connection end to which a battery is connected and an AC connection end, and performing power conversion between the DC connection end and the AC connection end by adjusting an on / off state of the switching element; a motor including a plurality of coils connected to the AC connection terminal; a first relay having one end connected to the DC connection end and the other end connected to a charging power input end, and a second relay having one end connected to a neutral point of the motor and the other end connected to the charging power input end; a controller for controlling states of the first relay and the second relay based on a result of comparing the voltage detection value of the battery with a maximum charging voltage provided by the charging equipment to the charging power input terminal, thereby providing the charging power provided by the charging equipment to the battery; Including, The controller, a first charging mode in which the first relay is shorted and the second relay is opened, so that the charging power is directly applied to the DC connection terminal to charge the battery; a first charging mode in which the charging power is applied to the neutral point of the motor by opening the first relay and shorting the second relay, and a second charging mode in which the charging power applied to the neutral point of the motor is converted in voltage magnitude by controlling the on / off state of the switching element and outputted to the DC connection terminal to charge the battery; The controller, a charging system using a motor drive system, the charging system calculating a remaining charging time required for the battery to be charged to a charging state corresponding to a maximum charging voltage, and charging the battery in the first charging mode if the remaining charging time is greater than a preset reference time, and charging the battery in the second charging mode if the remaining charging time is equal to or less than the reference time.

2. an inverter including a switching element connected between a DC connection end to which a battery is connected and an AC connection end, and performing power conversion between the DC connection end and the AC connection end by adjusting an on / off state of the switching element; a motor including a plurality of coils connected to the AC connection terminal; a first relay having one end connected to the DC connection end and the other end connected to a charging power input end, and a second relay having one end connected to a neutral point of the motor and the other end connected to the charging power input end; a controller for controlling states of the first relay and the second relay based on a result of comparing the voltage detection value of the battery with a maximum charging voltage provided by the charging equipment to the charging power input terminal, thereby providing the charging power provided by the charging equipment to the battery; Including, The controller, a first charging mode in which the first relay is shorted and the second relay is opened, so that the charging power is directly applied to the DC connection terminal to charge the battery; a first charging mode in which the charging power is applied to the neutral point of the motor by opening the first relay and shorting the second relay, and a second charging mode in which the charging power applied to the neutral point of the motor is converted in voltage magnitude by controlling the on / off state of the switching element and outputted to the DC connection terminal to charge the battery; The controller, If the detected voltage value of the battery is lower than the maximum charging voltage, charging the battery in the first charging mode; The controller, a charging system using a motor drive system, the charging system calculating a remaining charging time required for the battery to be charged to a charging state corresponding to a maximum charging voltage, and charging the battery in the first charging mode if the remaining charging time is greater than a preset reference time, and charging the battery in the second charging mode if the remaining charging time is equal to or less than the reference time.

3. The controller, determining one of the first charging mode and the second charging mode by applying the detected voltage value of the battery and the charging current provided by the charging device to a charging mode determination table according to a relationship between the voltage or the charging state of the battery and the charging current provided by the charging device; The charging mode determination table includes:

3. The charging system using a motor driving system according to claim 1 or 2, wherein it is determined that the first charging mode is performed when the voltage or the charging state of the battery is low and the charging current is low, and the second charging mode is performed when the voltage or the charging state of the battery is high and the charging current is high.

4. The controller, 3. The charging system using a motor driving system according to claim 1, wherein, during the first charging mode, when a voltage detection value of the battery becomes equal to or greater than the maximum charging voltage, or when a charging state corresponding to the voltage detection value of the battery becomes equal to or greater than the charging state corresponding to the maximum charging voltage, the charging system changes to the second charging mode.

5. The controller, 5. The charging system using a motor driving system according to claim 4, wherein, when a voltage detection value of the battery becomes equal to or greater than the maximum charging voltage or a charging state corresponding to the voltage detection value of the battery becomes equal to or greater than a charging state corresponding to the maximum charging voltage during the first charging mode, a charging current command of 0 is provided to the charging equipment, and then, when a current provided from the charging equipment becomes substantially 0, the first relay is opened, the second relay is shorted, and then the charging current command is increased.

6. A charging method using a motor driving system including: an inverter including a switching element connected between a DC connection end to which a battery is connected and an AC connection end, and performing power conversion between the DC connection end and the AC connection end by adjusting an on / off state of the switching element; a motor including a plurality of coils connected to the AC connection end; a first relay having one end connected to the DC connection end and the other end connected to a charging power input end; and a second relay having one end connected to a neutral point of the motor and the other end connected to the charging power input end, When charging is started, comparing a voltage detection value of the battery with a maximum charging voltage provided by the charging equipment to the charging power input terminal, or comparing a charging state of the battery corresponding to the voltage detection value of the battery with a charging state corresponding to the maximum charging voltage; performing a first charging mode in which the first relay is shorted and the second relay is opened to directly apply charging power to the DC connection terminal to charge the battery when the voltage detection value of the battery is lower than the maximum charging voltage or when a charging state of the battery corresponding to the voltage detection value of the battery is lower than a charging state corresponding to the maximum charging voltage; Including, and performing a second charging mode in which the charging power is applied to a neutral point of the motor by opening the first relay and shorting the second relay when the remaining charging time is equal to or less than the reference time, and controlling an on / off state of the switching element to convert a voltage magnitude of the charging power applied to the neutral point of the motor and outputting the converted voltage to the DC connection terminal, thereby charging the battery.

7. 7. The charging method using a motor driving system according to claim 6, further comprising: opening the first relay and shorting the second relay when a voltage detection value of the battery is equal to or greater than the maximum charging voltage, or when a charging state of the battery corresponding to the voltage detection value of the battery is equal to or greater than the charging state corresponding to the maximum charging voltage, thereby applying the charging power to a neutral point of the motor, and controlling an on / off state of the switching element to convert a voltage magnitude of the charging power applied to the neutral point of the motor and outputting the converted voltage to the DC connection terminal, thereby performing a second charging mode to charge the battery.

8. The method further includes a step of determining one of the first charging mode and the second charging mode by applying the voltage detection value of the battery and the charging current provided by the charging equipment to a charging mode determination table according to a relationship between the voltage or charging state of the battery and the charging current provided by the charging equipment, The charging mode determination table includes:

7. The charging method according to claim 6, wherein it is determined that the first charging mode is performed when the voltage or the state of charge of the battery is low and the charging current is low, and the second charging mode is performed when the voltage or the state of charge of the battery is high and the charging current is high.

9. 7. The charging method according to claim 6, further comprising: switching a charging method to a second charging mode in which, when a voltage detection value of the battery becomes equal to or greater than the maximum charging voltage or a charging state corresponding to the voltage detection value of the battery becomes equal to or greater than the maximum charging voltage during the first charging mode, the charging mode applies the charging power to a neutral point of the motor by opening the first relay and shorting the second relay, and controls an on / off state of the switching element to convert a voltage magnitude of the charging power applied to the neutral point of the motor and output the converted voltage to the DC connection terminal, thereby charging the battery.

10. 7. The charging method according to claim 6, further comprising the step of providing a charging current command of 0 to the charging equipment when a voltage detection value of the battery becomes equal to or greater than the maximum charging voltage or a charging state corresponding to the voltage detection value of the battery becomes equal to or greater than a charging state corresponding to the maximum charging voltage during the first charging mode, and then opening the first relay and shorting the second relay when a current provided from the charging equipment becomes substantially 0.

Images