POWER CONVERSION DEVICE FOR ELECTRIC VEHICLES AND METHOD FOR OPERATION THEREOF
Patent Information
- Application Number
- DE102023211733
- Authority / Receiving Office
- DE · DE
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-08-04
- Filing Date
- 2023-11-24
- Publication Date
- 2025-02-06
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
TECHNICAL FIELDThe present invention relates to a power conversion device for electric vehicles and an operation method thereof.BACKGROUNDFor the operation of an electric vehicle (EV), an on-board charger (OBC) is provided for charging a high-voltage battery with commercial alternating current in the electric vehicle.Generally, the OBC includes a power factor correction (PFC) circuit that corrects the power factor of the commercial AC current, and a DC-DC converter that converts the current into a voltage required for the high-voltage battery.Recently, development of vehicle-to-grid (V2G) or vehicle-to-load (V2L) technologies for supplying the energy stored in a high voltage battery of an electric vehicle to a system or an electric load has been required.Accordingly, electric vehicles are required to be equipped with circuits for various power conversions, such as circuits for realizing V2G or V2L, and chargers for easily charging the batteries.In addition, different types of alternating current are used in each of countries (e.g., Europe: (three-phase) 230 VAC / 50 Hz, North America: (single-phase) 240 VAC / 60 Hz, Korea: (single-phase) 220 VAC / 60 Hz, etc.), and also in a V2L socket, symmetrical current (North America 240 VAC) and asymmetrical current (Korea / Europe / North America 120 VAC) are used, so that a current conversion circuit that can be generally used for different types of current and sockets is required.Demand for electric vehicles is increasing, and in a case where various power conversion circuits are individually provided in an electric vehicle to meet various demands, a large number of electric components are required to implement the respective power conversion circuits, and thus problems may arise in that a circuit structure becomes complicated and the cost for implementing the circuit increases.This prior art is technical information available to the inventor in deriving embodiments of the present invention or acquired during the process of deriving embodiments of the present invention, and may not necessarily be regarded as a known prior art disclosed to the generality before filing the application.SUMMARYThe present invention relates to an electric vehicle power conversion device and a method for operating the same. Particular embodiments relate to a power conversion device for electric vehicles capable of supplying power to loads using various kinds of power and an operation method thereof.Disclosed embodiments have been made in response to the above-mentioned requirements, and embodiments of the present invention provide a power conversion device for electric vehicles capable of supplying power to loads using various types of power and an operation method thereof.Moreover, embodiments of the present invention provide a power conversion device for electric vehicles capable of realizing power conversion for supplying balanced sockets and balanced sockets for each country using a minimum number of electric components, and an operation method thereof.The technical objects of the embodiments of the present invention are not limited to the above-mentioned points, and from the following description, those having ordinary knowledge in the field of the present invention will be able to clearly understand other objects intended with the embodiments of the present invention.As technical means for achieving the above-described objects, there can be provided an electric vehicle power conversion device capable of supplying power to loads using various kinds of power, and an operation method thereof.According to embodiments of the present invention, the above and other objects can be achieved by providing a power conversion apparatus for electric vehicles including a battery, a relay circuit connected to a charge / discharge output via first power lines, a power factor correction circuit connected to the relay circuit via second power lines between the relay circuit and the battery, a discharge output connected to branch lines branching from each of the second power lines, and a controller configured to control the relay circuit and the power factor correction circuit so that power is supplied from the battery to a load using asymmetric power, a discharge output connected to branch lines branching from each of the second power lines, and a controller configured to:, controlling the relay circuit and the power factor correction circuit so that current is supplied from the battery to a load using asymmetric current or to a load using symmetric current connected to the discharge output.According to an embodiment, the second power lines may include (2-1)-th to (2-3)-th power lines, and the branch lines may include first to third branch lines connected to the (2-1)-th to (2-3)-th power lines, respectively.In an embodiment, the discharge output may include a positive (+) terminal connected to the first branch line, a negative (-) terminal connected to the second branch line, and a neutral terminal connected to the third branch line.According to an embodiment, a positive (+) voltage may be applied to the (2-1)-th power line, a negative (-) voltage may be applied to the (2-2)-th power line, and a zero voltage may be applied to the (2-3)-th power line.According to one embodiment, the asymmetrical load can be connected to the positive pole (+) and the neutral conductor.According to an embodiment, the asymmetrical load can be connected to the negative pole (-) and the neutral conductor.According to an embodiment, the balanced power load may be connected to the positive (+), negative (-) and neutral terminals.According to an embodiment, the relay circuit may include an L1 relay connected to the (2-1)th power line, an L1-L2 relay and an L2 relay connected in parallel to the (2-2)th power line, and an L3 relay and a neutral point relay connected in parallel to the (2-3)th power line.According to an embodiment, the power factor correction circuit may include a first arm connected to the (2-1)th power line, a second arm connected to the (2-2)th power line, and a third arm connected to the (2-3)th power line.According to an embodiment, when the asymmetric load is connected to the discharge output, the controller may turn off the L1 relay, the L1-L2 relay, the L2 relay, the L3 relay, and the neutral point relay, and control the first to third branches so that a positive (+) voltage is applied to the (2-1)-th power line or a negative (-) voltage is applied to the (2-2)-th power line.According to an embodiment, when the asymmetric load is connected to the discharge output, the controller may turn on the L1 relay, the L1-L2 relay, and the neutral point relay, turn off the L2 relay, and the L3 relay, and control the first to third arms so that a positive (+) voltage is applied to the (2-1)-th power line or a negative (-) voltage is applied to the (2-2)-th power line.According to an embodiment, the charge / discharge output may include an L1 terminal connected to the L1 relay and the L1-L2 relay via a (1-1)-th power line, and a neutral terminal connected to the neutral point relay via a (1-2)-th power line, and when an external load of the vehicle is connected to the L1 terminal and the neutral terminal, the positive (+) voltage supplied to the (2-1)-th power line may be supplied to the L1 terminal or the negative (-) voltage supplied to the (2-2)-th power line may be supplied to the L1 terminal, and thus power may be simultaneously supplied to the load using asymmetric current and the external vehicle load.According to an embodiment, when the balanced load is connected to the discharge output, the controller may turn off the L1 relay, the L1-L2 relay, the L2 relay, the L3 relay, and the neutral point relay, and perform PWM control of the first to third arms so that a positive (+) voltage is applied to the (2-1)-th power line, a negative (-) voltage is applied to the (2-2)-th power line, and a zero voltage is applied to the (2-3)-th power line.According to an embodiment, when the load using balanced power is connected to the discharge output, the controller may turn on the L1 relay and the neutral point relay, turn off the L1-L2 relay, the L2 relay, and the L3 relay, and perform PWM control on the first to third arms so that a positive (+) voltage is applied to the (2-1)-th power line, a negative (-) voltage is applied to the (2-2)-th power line, and a zero voltage is applied to the (2-3)-th power line.According to an embodiment, the charging / discharging outlet may include an L1 terminal connected to the L1 relay and the L1-L2 relay via the (1-1)th power line, and a neutral terminal connected to the neutral point relay via the (1-2)th power line, and when an external vehicle load is connected to the L1 terminal and the neutral terminal, the positive (+) voltage supplied to the (2-1)th power line may be supplied to the L1 terminal, and the zero voltage supplied to the (2-3)th power line may be supplied to the neutral terminal, and thus, power may be simultaneously supplied to the load using the symmetrical current and the external vehicle load.According to another embodiment of the present invention, there is provided a method of operating a power conversion device for electric vehicles, the method comprising detecting whether an off-vehicle load is connected to a charge / discharge output or whether an on-vehicle load is connected to a discharge output, determining whether the on-vehicle load is a load that uses asymmetric power or a load that uses symmetric power when the on-vehicle load is connected to the discharge output, supplying asymmetric power to the load that uses asymmetric power based on the power of a battery when the on-vehicle load is the load that uses asymmetric power, and supplying symmetric power to the load that uses symmetric power based on the power of the battery when the on-vehicle load is the load that uses symmetric power.According to an embodiment, the asymmetric power supply may include supplying the asymmetric power load with a positive (+) voltage and a zero voltage when the asymmetric power load is connected to a positive (+) terminal and a neutral terminal of the discharge output.According to an embodiment, the supplying of asymmetric power may include supplying a negative (-) voltage and a zero voltage to the load utilizing asymmetric power when the load utilizing asymmetric power is connected to a negative (-) terminal and the neutral terminal of the discharge output.According to an embodiment, the balanced power supply may include supplying the load with a positive (+) voltage, a negative (-) voltage, and a zero voltage using balanced power.According to an embodiment, the method of operating a power conversion device for electric vehicles may include supplying a positive (+) voltage and a zero voltage to the off-vehicle load and the load using asymmetric power when the off-vehicle load is connected to the charging / discharging output and the load using asymmetric power is connected to the discharging output.According to an embodiment, the method of operating a power conversion device for electric vehicles may include supplying a negative (-) voltage and a zero voltage to the off-vehicle load and the load using asymmetric power when the off-vehicle load is connected to the charging / discharging output and the load using asymmetric power is connected to the discharging output.According to an embodiment, the method of operating a power conversion device for electric vehicles may include supplying a positive (+) voltage and a zero voltage to the external load of the vehicle and supplying a positive (+) voltage, a negative (-) voltage and a zero voltage to the load using symmetric power when the external load of the vehicle is connected to the charge / discharge output and the load using symmetric power is connected to the discharge output.Specific details according to various embodiments of the present invention except for the means for solving the above problems are included in the following description and drawings.BRIEF DESCRIPTION OF THE DRAWINGSThe above and other objects, features and other advantages of embodiments of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. 1 is a diagram showing a configuration of a power conversion device for electric vehicles according to an embodiment of the present invention; FIG. 2 is a diagram showing a configuration of a relay circuit according to an embodiment of the present invention; FIG. 3 is a diagram showing a configuration of a power factor correction circuit according to an embodiment of the present invention; FIG. 4 is a diagram for describing the operation of the electric vehicle power conversion device according to an embodiment of the present invention; FIG. 5 is a diagram showing a power path in a case where a battery is charged using the electric vehicle power conversion device according to an embodiment of the present invention; FIG. 6 is a diagram showing a power path in a case where power is supplied to an exterior vehicle load using the electric vehicle power conversion device according to an embodiment of the present invention; and FIG. 7 is a diagram showing a current path in a case where power is supplied to a vehicle interior load using the electric vehicle power conversion device according to an embodiment of the present invention.DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTSThe advantages and features of embodiments of the present invention and the manner in which they can be achieved will be apparent by reference to embodiments which will be described in detail below in connection with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and can be embodied in many different forms. Rather, these example embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the application to those skilled in the art. Therefore, the scope of the embodiments of the present invention is intended to be defined by the claims.The shapes, sizes, ratios, angles, numbers, and the like illustrated in the drawings to describe various embodiments of the present invention are given by way of example only, and thus the embodiments of the present invention are not limited to the drawings. The same or very similar elements are denoted by the same reference numerals throughout the description. Moreover, in describing embodiments of the present invention, detailed description of related known technologies will be omitted if it may make the subject matter of the embodiments of the present invention rather unclear. In the present specification, when the terms "comprise", "include", and the like are used, other elements may be added unless the term "only" is used. An element described in the singular is intended to include a plurality of elements unless the context clearly indicates otherwise.In interpreting the constituent elements included in the various embodiments of the present invention, the constituent elements are interpreted to include an error range, although it is not expressly described.In describing the various embodiments of the present invention, when temporal relationships are described, e.g., when the temporal relationship between two actions is described as being "after", "subsequent", "next", "before", or the like, the actions may not occur sequentially unless the term "immediately" or "straight" is used.In describing the various embodiments of the present invention, although terms such as "first" and "second" may be used to describe various elements, these terms are merely used to distinguish the same or similar elements from each other. Therefore, in the present specification, an element modified by "first" may be the same as an element modified by "second" within the technical scope of the present invention unless otherwise mentioned.It is understood that although the terms first, second, A, B, (a), (b), etc. may be used herein to describe various elements of embodiments of the present invention, these terms are only used to distinguish one element from another element, and the need, order, or sequence of the corresponding elements are not limited by these terms. It will be understood that when an element is referred to as being "connected to", "coupled to", or "accessing" another element, an element may be "connected to", "coupled to", or "accessing" another element via another element, although an element may be directly connected to another element or may directly access another element."At least one" is to be understood to include all combinations of one or more associated elements. For example, "at least a first, second, and third element" means not only the first, second, or third element but also all combinations of two or more of the first, second, and third elements.The respective features of the various embodiments of the present invention may be partially or completely coupled and combined with each other, and various technical links and operations thereof are possible. These various embodiments may be carried out independently of each other or in association with each other.Embodiments of the present invention will be described below with reference to the accompanying drawings and examples. Since, for convenience of description, the scales of the components shown in the drawings have actually different scales from each other, the scales are not limited to the scales shown in the drawings.Hereinafter, a power conversion device for electric vehicles and an operation method thereof according to embodiments of the present invention will be described with reference to the accompanying drawings.FIG. 1 is a diagram showing a configuration of a power conversion device 1 for electric vehicles according to an embodiment of the present invention.Referring to FIG. 1, the electric vehicle power conversion device 1 according to an embodiment of the present invention may be a bidirectional on-board charger (OBC) mounted in an electric vehicle.The electric vehicle power conversion device 1 according to the embodiment may include a relay circuit 100, a power factor correction (PFC) circuit 200, a DC-DC converter 300, and a controller 400.The relay circuit 100 may be connected to a charging / discharging socket (or a charging / discharging terminal or an external V2L output) 10, may provide current supplied to the power factor correction circuit 200 via the charging / discharging output 10, and may provide current supplied to the charging / discharging output 10 from the power factor correction circuit 200.The charge / discharge output 10 may support a battery charging mode and a battery discharging mode.When an AC power source is connected to the charging / discharging output 10 (charging mode), the relay circuit 100 may relay the current supplied from the AC power source to the power factor correction circuit 200. The AC power source may be, for example, a single-phase AC power source or a three-phase AC power source.When a load is connected to the charge / discharge output 10 (discharge mode), the relay circuit 100 may supply the current supplied from the power factor correction circuit 200 to the charge / discharge output 10. A load located outside the electric vehicle may be connected to the charging / discharging output 10, and a load connected to the charging / discharging output 10 may be referred to as an "off-vehicle load".The charge / discharge output 10 may include a first terminal L 1, a second terminal L 2, a third terminal L 3, and a neutral terminal N.In the charging mode, an L1-phase AC voltage may be input to the first terminal L 1, an L2-phase AC voltage may be input to the second terminal L 2, and an L3-phase AC voltage may be input to the third terminal L 3. In the discharge mode, a load may be connected to the first terminal L 1 and the neutral terminal N.The relay circuit 100 may be disposed between the charge / discharge output 10 and the power factor correction circuit 200, and may include a plurality of relays that are turned on and off in response to control by the controller 400.The relay circuit 100 may transmit the power supplied from the charging / discharging output 10 to the power factor correction circuit 200 and transmit the power supplied from the power factor correction circuit 200 to the charging / discharging output 10.The relay circuit 100 may be connected to the charging / discharging output 10 via a plurality of first power lines PL_ 11, PL_ 12, PL_ 13, and NL, and may be connected to the power factor correction circuit 200 via a plurality of second power lines PL_ 21, PL_ 22, and PL_ 23.Here, the plurality of first power lines may include the (1-1)-th power line PL_ 11 connected to the first terminal L 1, the (1-2)-th power line PL_ 12 connected to the second terminal L 2, the (1-3)-th power line PL_ 13 connected to the third terminal L 3, and the neutral line NL connected to the neutral terminal N.In addition, the plurality of second power lines may include the (2-1)-th power line PL_ 21, the (2-2)-th power line PL_ 22, and the (2-3)-th power line PL_ 23.The power factor correction circuit 200 may be disposed between the relay circuit 100 and the DC-DC converter 300, convert an AC voltage transmitted from the relay circuit 100 into a DC voltage, output the DC voltage, and simultaneously correct the power factor of the voltage.That is, the power factor correction circuit 200 performs a rectification function in which an AC voltage is converted into a DC voltage, and can increase a power factor by decreasing a phase difference between the input current and the input voltage.In addition, the power factor correction circuit 200 may supply the voltage supplied from the DC-DC converter 300 to the relay circuit 100.A discharge output (or discharge terminal) 20 may be connected between the relay circuit 100 and the power factor correction circuit 200 via a branch line BL.The discharge output (or internal V2L output) 20 may be provided inside the electric vehicle, for example, and a load connected to the discharge output 20 may be referred to as "vehicle internal load".The discharge output 20 may include a first terminal A, a second terminal B, and a neutral terminal N'. In this case, the first terminal A can be a positive (+) terminal and the second terminal B can be a negative (-) terminal.The first terminal A may be connected to the (2-1)-th power line PL_ 21 via a first branch line BL_ 1, the second terminal B may be connected to the (2-2)-th power line PL_ 22 via a second branch line BL_ 2, and the neutral terminal N' may be connected to the (2-3)-th power line PL_ 23 via a third branch line BL_ 3.That is, the first branch line BL_ 1 may connect the first terminal A and the (2-1)-th power line PL_ 21, the second branch line BL_ 2 may connect the second terminal B and the (2-2)-th power line PL_ 22, and the third branch line BL_ 3 may connect the neutral terminal N' and the (2-3)-th power line PL_ 23.The DC-DC converter 300 is disposed between the power factor correction circuit 200 and the battery 30, and may convert the voltage supplied from the power factor correction circuit 200 depending on the control of the controller 400 and supply the converted voltage to the battery 30.Moreover, the DC-DC converter 300 may convert the voltage supplied from the battery 30 in response to the control by the controller 400 and supply the converted voltage to the power factor correction circuit 200.The controller 400 may allow the electric vehicle power conversion device 1 to perform the battery charging mode in which the battery 30 is charged based on an external AC power source and the discharging mode in which the power of the battery 30 is output to the charging / discharging output 10 or the discharging output 20.As the external AC power source, for example, a three-phase or a single-phase AC power source may be used.The battery discharge mode may include a first battery discharge mode in which the power of the battery 30 is output to the charge / discharge output 10 and a second discharge mode in which the power of the battery 30 is output to the discharge output 20.When the AC power source is connected to the charging / discharging output 10, the controller 400 may control the relay circuit 100, the power factor correction circuit 200, and the DC-DC converter 300 to charge the battery 30 based on the AC power source.When an off-board load is connected to the charge / discharge output 10, the controller 400 may control the relay circuit 100, the power factor correction circuit 200, and the DC-DC converter 300 to supply the power of the battery 30 to the off-board load connected to the charge / discharge output 10.For example, the external load of the vehicle may be connected to the first terminal L 1 and the neutral terminal N, but the embodiments of the present invention are not limited thereto.When an in-vehicle load is connected to the discharge output 20, the controller 400 may control the relay circuit 100, the power factor correction circuit 200, and the DC-DC converter 300 so as to supply the power of the battery 30 to the out-vehicle load connected to the charge / discharge output 10.For example, the interior load of the vehicle may be connected to the first terminal A and the neutral terminal N', to the second terminal B and the neutral terminal N', or to the first terminal A, the second terminal B and the neutral terminal N'.The load in the vehicle interior connected to the discharge output 20 may be an asymmetric power load or a symmetric power load.An asymmetric power load may be a load operating at a positive (+) voltage (e.g., +120 V) and 0 V, or may be a load operating at a negative (-) voltage (e.g., -120 V) and 0 V.The controller 400 may control the relay circuit 100 and the power factor correction circuit 200 depending on whether an asymmetric power load or a symmetric power load is connected to the discharge output 20.According to an embodiment, the controller 400 may be implemented to detect whether a load is connected to the charge / discharge output 10 and the discharge output 20.For this purpose, one of the cable connection detection sensors may be provided in the charging / discharging outlet 10 and the discharging socket 20 for each terminal. The detection sensor may output a detection signal to the controller 400 when a cable is connected (or inserted) to a terminal.Accordingly, the controller 400 may recognize (or determine) whether loads are connected to the charge / discharge output 10 and the discharge output 20 based on a detection signal output from the detection sensor, and may recognize which terminals of the outputs 10 and 20 are connected to loads.When an asymmetric power load is connected to the discharge output 20, the controller 400 may control the relay circuit 100 and the power factor correction circuit 200 to supply the asymmetric power to the load.Further, when a balanced power load is connected to the discharge output 20, the controller 400 may control the relay circuit 100 and the power factor correction circuit 200 to supply the balanced power to the load.In an embodiment, a first filter 500 may be connected between the charge / discharge output 10 and the relay circuit 100, and a second filter 600 may be connected between the relay circuit 100 and the power factor correction circuit 200.The first filter 500 may remove electric noise included in the AC voltage transmitted from the charging / discharging output 10, and the second filter 600 may remove electric noise included in the AC voltage transmitted from the relay circuit 100.FIG. 2 is a diagram showing a configuration of the relay circuit 100 according to an embodiment of the present invention.Referring to FIGS. 1 and 2, the relay circuit 100 according to an embodiment of the present invention may include a precharge relay RLY_Pre, an L1 relay RLY_L 1, an L1-L2 relay RLY_L 1_L 2, an L2 relay RLY_L 2, an L3 relay RLY_L 3, and a neutral point relay RLY_N, but the configuration of the relay circuit 100 is not limited thereto.The precharge relay RLY_Pre, the L1 relay RLY_L 1, the L1-L2 relay RLY_L 1_L 2, the L2 relay RLY_L 2, the L3 relay RLY_L 3, and the neutral point relay RLY_N may be controlled by the controller 400.The precharge relay RLY_Pre may be connected in series between the (1-1)-th power line PL_ 11 connected to the first terminal L 1 and the (2-1)-th power line PL_ 21, and the L 1 relay RLY_L 1 may be connected in series between the (1-1)-th power line PL_ 11 connected to the first terminal L 1 and the (2-1)-th power line PL_ 21.Accordingly, the precharge relay RLY_Pre and the L 1 relay RLY_L 1 may be connected in parallel between the (1-1)-th power line PL_ 11 and the (2-1)-th power line PL_ 21.The L 1-L 2 relay RLY_L 1_L 2 may be connected in series between the (1-1)-th power line PL_ 11 and the (2-2)-th power line PL_ 22, and the L 2 relay RLY_L 2 may be connected in series between the (1-2)-th power line PL_ 12 and the (2-2)-th power line PL_ 22.In this way, one end of the L1-L2 relay RLY_L1_L2 may be connected to the (1-1)-th power line PL_11, one end of the L2 relay RLY_L2 may be connected to the (1-2)-th power line PL_12, and the other end of the relay RLY_L1_L2 and the other end of the L2 relay RLY_L2 may be connected in common to the (2-2)-th power line PL_22.Accordingly, the L 1-L 2 relay RLY_L 1_L 2 and the L 2 relay RLY_ 2 may be connected in parallel to the (2-2)-th power line PL_ 22.The L3 relay RLY_L 3 may be connected in series between the (1-3)-th power line PL_ 13 and the (2-3)-th power line PL_ 23, and the neutral point relay RLY_N may be connected between the neutral line NL and the (2-3)-th power line PL_ 23.One end of the L3 relay RLY_L 3 may be connected to the (1-3)-th power line PL_ 13, one end of the neutral point relay RLY_N may be connected to the neutral line NL, and the other end of the L3 relay RLY_L 3 and the other end of the neutral point relay RLY_N may be commonly connected to the (2-3)-th power line PL_ 23.Accordingly, the L3 relay RLY_L 3 and the neutral point relay RLY_N may be connected in parallel to the (2-3)-th power line PL_ 23.FIG. 3 is a diagram showing a configuration of the power factor correction circuit 200 according to an embodiment of the present invention.Referring to FIGS. 1 to 3, the power factor correction circuit 200 according to an embodiment of the present invention may include first to third input inductances Lg 1, Lg 2, and Lg 3, a DC capacitor Cdc, and first to third legs L 11, L 12, and L 13, but the configuration of the power factor correction circuit 200 is not limited thereto.One end of the first input inductor Lg 1 may be connected to the (2-1)th power line PL_ 21, and the other end of the first input inductor Lg 1 may be connected to the first arm L 11. One end of the second input inductor Lg 2 may be connected to the (2-2)th power line PL_ 22, and the other end of the second input inductor Lg 2 may be connected to the second arm L 12. One end of the third input inductor Lg 3 may be connected to the (2-3)th power line PL_ 23, and the other end of the third input inductor Lg 3 may be connected to the third arm L 13.The DC capacitor Cdc may be connected in parallel between a first DC link D 1 and a second DC link D 2. The DC capacitor Cdc may be connected in parallel to the first to third arms L 11, L 12, and L 13.The first arm L 11 may include two switching elements SW 1 and SW 2 connected in series between the first DC link D 1 and the second DC link D 2, and may be connected to the (2-1)th power line PL_ 21 via the first input inductor Lg 1.The second arm L 12 may include two switching elements SW 3 and SW 4 connected in series between the first DC link D 1 and the second DC link D 2, and may be connected to the (2-2)-th power line PL_ 22 via the second input inductor Lg 2.The third arm L 13 may include two switching elements SW 5 and SW 6 connected in series between the first DC link D 1 and the second DC link D 2, and may be connected to the (2-3)th power line PL_ 23 via the third input inductor Lg 3.The other end of the first input inductor Lg 1 may be connected between the first switching element SW 1 and the second switching element SW 2. The other end of the second input inductor Lg 2 may be connected between the third switching element SW 3 and the fourth switching element SW 4. The other end of the third input inductor Lg 3 may be connected between the fifth switching element SW 5 and the sixth switching element SW 6.The first to sixth switching elements SW 1 to SW 6 of the reactive power compensation circuit 200 may be controlled by the controller 400.FIG. 4 is a diagram for describing the operation of the electric vehicle power conversion device according to an embodiment of the present invention. FIG. 5 is a diagram showing a current path in a case where the battery 30 is charged using the electric vehicle power conversion device according to an embodiment of the present invention. FIG. 6 is a diagram showing a current path in a case where power is supplied to an external load vehicle using the electric vehicle power conversion device according to an embodiment of the present invention. FIG. 7 is a diagram showing a current path in a case where power is supplied to a vehicle interior load using the electric vehicle power conversion device according to an embodiment of the present invention.The stepwise operation shown in Fig. 4 can be described as described with reference to Figs. 1 to 3.The operation of the electric vehicle power conversion device 1 will be described with reference to FIGS. 1 to 7, focusing on the control of the controller 400.First, the controller 400 may recognize whether power or a load is connected to the charge / discharge output 10 and the discharge output 20 (S 400).In step S 400, the controller 400 may recognize whether a power source or a load is connected to the charging / discharging output 10 and the discharging socket 20 based on detection signals from a cable connection detection sensor for each terminal provided in the charging / discharging output 10 and the discharging output 20.When the controller 400 recognizes that a power source is connected to the charge / discharge output 10 (S410), the battery 30 may be charged based on the power source connected to the charge / discharge output 10, as shown in FIG. 5 (S420).The current source connected to the charging / discharging output 10 can be, for example, a three-phase alternating current source or a single-phase alternating current source.Control of charging of the battery 30 with an external AC power source via a power conversion device may be accomplished by various methods known in the art.For example, the controller 400 may turn on the L1 relay RLY_L 1, the L2 relay RLY_L 2, and the L3 relay RLY_L 3, and control (or switch) the first arm L 11, the second arm L 12, and the third arm L 13 of the power factor correction circuit 200 so as to charge the battery 30 based on a three-phase AC voltage.When the controller 400 determines that a load ("off-board load") is connected to the charge / discharge output 10 (S 430), the power of the battery 30 may be supplied to the load connected to the charge / discharge output 10 as shown in FIG. 6 (S 440).In step S 440, the controller 400 may turn on the L1 relay RLY_L 1, the L1-L2 relay RLY_L 1_L 2, and the neutral point relay RLY_N, and turn off the L2 relay RLY_L 2 and the L3 relay RLY_L 3.Accordingly, the (1-1)-th power line PL_ 11 and the (2-1)-th power line PL_ 21 may be connected, and the neutral line NL and the (2-3)-th power line PL_ 23 may be connected. According to this connection relationship, the first terminal L 1 of the charging / discharging output 10 and the first arm L 11 of the power factor correction circuit 200 may be connected, and the neutral terminal N of the charging / discharging output 10 and the third arm L 13 of the power factor correction circuit 200 may be connected.In this way, the controller 400 may control (or switch) the first arm L 11 and the third arm L 13 of the power factor correction circuit 200 so that the power of the battery 30 is output to the charge / discharge output 10 in a state in which the charge / discharge output 10 and the power factor correction circuit 200 are connected according to the operation of the relay circuit 100.In this case, the controller 400 may perform single-phase totem-pole control for the first arm L 11 and the third arm L 13.Since the first branch line BL_ 1 is connected to the (2-1)-th power line PL_ 21 and the third branch line BL_ 3 is connected to the (2-3)-th power line PL_ 23, when a load is connected to the first terminal A and the neutral terminal N' of the discharge outlet 20, the current of the battery 30 can also be supplied to the load.That is, when the L1 relay RLY_L 1, the L1-L2 relay RLY_L 1_L 2, and the neutral point relay RLY_N are turned on and the L2 relay RLY_L 2 and the L3 relay RLY_L 3 are turned off, the power of the battery 30 may be supplied to a load connected to the charge / discharge output 10 and a load connected to the first terminal A and the neutral terminal N' of the discharge terminal 20.When the controller 400 recognizes that a load ("vehicle interior load") is connected to the discharge output 20 (S 450), the power of the battery 30 may be supplied to the load connected to the discharge output 20, as shown in FIG. 7.Here, the controller 400 may determine whether the load connected to the discharge output 20 is an asymmetric power load or a symmetric power load (S 460).In step S460, the controller 400 may determine whether the load is connected to the first terminal A and the neutral terminal N', whether the load is connected to the second terminal B and the neutral terminal N', or whether the load is connected to the first terminal A, the second terminal B, and the neutral terminal N'.Here, when the load is connected to the first terminal A and the neutral terminal N' of the discharge output 20, or to the second terminal B and the neutral terminal N' of the discharge output 20, the controller 400 may determine that the load connected to the discharge output 20 is an asymmetric power load.The controller 400 may determine that the load connected to the discharge output 20 is a balanced power load when the load is connected to the first terminal A, the second terminal B, and the neutral terminal N'.When it is determined that the load is a load using asymmetric power (S 470), the controller 400 may control the relay circuit 100 and the power factor correction circuit 200 to supply asymmetric power to the load (S 480).In step S 480, the controller 400 may shut down all of the L 1 relay RLY_L 1, L 1 to L 2 relay RLY_L 1_L 2, L 2 relay RLY_L 2, L 3 relay RLY_L 3, and the neutral point relay RLY_N.Accordingly, the current from the battery 30 is cut off by the relay circuit 100 and thus is not supplied to the charge / discharge output 10, and the current from the battery 30 can be supplied to the discharge output 20 via the branch lines BL_ 1, BL_ 2, and BL_ 3 connected to the second power lines PL_ 21, PL_ 22, and PL_ 23.Accordingly, the power of the battery 30 may be supplied to a load connected to the discharge output 20, and as the load, an asymmetric power load or a symmetric power load may be used.A load using asymmetric power may be connected to the first terminal A (+) and the neutral terminal N' of the discharge output 20, or to the second terminal B (-) and the neutral terminal N' of the discharge output 20.A load of balanced power may be connected to the first terminal A(+), the second terminal B(-) and the neutral N' of the discharge output 20.The controller 400 may perform single-phase dead-beam control of the first to third branches L 11, L 12, and L 13 of the power factor correction circuit 200 when an asymmetric power load is connected to the discharge output 20. In addition, the controller 400 may perform three-phase pulse width modulation (PWM) control on the first to third arms L 11, L 12, and L 13 of the power factor correction circuit 200 when a balanced power load is connected to the discharge output 20.When it is determined that the load is a balanced power load (S 409), the controller 400 may control the relay circuit 100 and the power factor correction circuit 200 to supply the balanced power load (S 500).In step S 500, the controller 400 may turn off the L1 relay RLY_L 1, the L1-L2 relay RLY_L 1_L 2, the L2 relay RLY_ 2, the L3 relay RLY_ 3, and the neutral point relay RLY_N.Then, the controller 400 may perform PWM control on the first to third arms L 11, L 12, and L 13 such that a positive (+) voltage is applied to the (2-1)-th power line PL_ 21, a negative (-) voltage is applied to the (2-2)-th power line PL_ 22, and 0 V is applied to the (2-3)-th power line PL_ 23.Accordingly, the positive (+) voltage, the negative (-) voltage, and 0 V can be applied to the terminals A, B, and N' of the discharge output 20 via the branch lines BL_ 1, BL_ 2, and BL_ 3 connected to the second power lines PL_ 21, PL_ 22, and PL_ 23.In step S 500, the controller 400 may turn on the L1 relay RLY_L 1 and the neutral point relay RLY_N, and turn off the L1-L2 relay RLY_L 1_L 2, the L2 relay RLY_ 2, and the L3 relay RLY_ 3.Then, the controller 400 may perform PWM control on the first to third arms L 11, L 12, and L 13 such that a positive (+) voltage is applied to the (2-1)-th power line PL_ 21, a negative (-) voltage is applied to the (2-2)-th power line PL_ 22, and 0 V is applied to the (2-3)-th power line RLY_ 23.When the L1 relay RLY_L 1 and the neutral point relay RLY_N are turned on, the positive (+) voltage may be applied to the L1 terminal L 1 of the charging / discharging output 10 and 0 V may be applied to the neutral terminal N of the charging / discharging output 10.When an off-vehicle load is connected to the terminal L 1 and the neutral terminal N of the charging / discharging output 10, the power from the battery 30 may be supplied to the off-vehicle load.Therefore, a load with symmetrical power connected to the discharge output 20 and a load external to the vehicle connected to the charge / discharge output 10 can be simultaneously supplied with power.According to the electric vehicle power conversion device (1) and its operation method according to an embodiment of the present invention, the electric vehicle power conversion device (1) can provide a positive (+) voltage and a zero voltage to a load that uses asymmetric power in a case where the load that uses asymmetric power is connected to the positive (+) terminal and the neutral terminal of the discharge output 20.According to an embodiment of the present invention, the electric vehicle power conversion device 1 may supply a negative (-) voltage and the zero voltage to a load that uses asymmetric power when the load that uses asymmetric power is connected to the negative (-) terminal and the neutral terminal of the discharge output 20.According to an embodiment of the present invention, the electric vehicle power conversion device 1 may supply the positive (+) voltage, the negative (-) voltage, and the zero voltage to a load with balanced power.According to an embodiment of the present invention, the electric vehicle power conversion device 1 may provide the positive (+) voltage and the zero voltage to an off-vehicle load and an asymmetric load in a case where the off-vehicle load is connected to the charging / discharging output 10 and the asymmetric load is connected to the discharging output 20.According to an embodiment of the present invention, the electric vehicle power conversion device 1 may provide the negative (-) voltage and the zero voltage to an off-vehicle load and an asymmetric load in a case where the off-vehicle load is connected to the charging / discharging output 10 and the asymmetric load is connected to the discharging output 20.According to an embodiment of the present invention, the electric vehicle power conversion device 1 may supply the positive (+) voltage and the zero voltage to an off-vehicle load and supply the positive (+) voltage, the negative (-) voltage and the zero voltage to a balanced power load in a case where the off-vehicle load is connected to the charge / discharge output 10 and the balanced power load is connected to the discharge output 20.The electric vehicle power conversion device 1 according to an embodiment of the present invention described above can power various kinds of loads, for example, an outdoor load in the vehicle, an indoor load in the asymmetric power vehicle, and an indoor load in the symmetric power vehicle.Therefore, the electric vehicle power conversion device 1 according to an embodiment of the present invention can be applied to balanced terminals and balanced terminals, and can be applied to vehicles regardless of the type of power required for each country. Moreover, since the power supply of the electric vehicle power conversion device 1 according to an embodiment of the present invention can be realized with a relay circuit and a power factor correction circuit, objects of the embodiments of the present invention can be achieved with a minimum number of electrical components.According to an embodiment of the present invention, it is possible to provide a power conversion device for electric vehicles capable of supplying power to loads using various kinds of power and an operation method thereof.Moreover, according to an embodiment of the present invention, it is possible to provide an electric vehicle power conversion device capable of realizing power conversion for supplying power to symmetrical and asymmetrical outlets for each country using a minimum number of electric components and an operation method.By using the electric vehicle power conversion device and its operation methods according to an embodiment of the present invention, power can be supplied to a balanced socket and an balanced socket using a power conversion device, and power can be supplied to loads using different kinds of power.The effects of embodiments of the present invention are not limited to the above-mentioned effects, and other, non-mentioned effects will be clearly understood by those skilled in the art from the present specification.Since the contents of the problem to be solved, the means for solving the problem and the above-mentioned effect do not specify essential features of the claims, the scope of the claims is not limited by the matters described in the contents of the specification.Although the embodiments of the present invention have been described in detail with reference to the accompanying drawings, the embodiments of the present invention are not necessarily limited to these embodiments and may be modified and implemented in various ways without departing from the technical spirit of the present invention. Therefore, the embodiments disclosed in this specification are not intended to limit the technical spirit of the present invention but to explain it, and the scope of the technical spirit of the present invention is not limited by these embodiments. It should therefore be understood that the above-described embodiments are illustrative in all respects and are not restrictive. The scope of the embodiments of the present invention should be construed according to the claims, and all technical ideas within the respective range should be considered to be included in the scope of the embodiments of the present invention.
Claims
A power conversion device for electric vehicles, the device comprising: a battery; a relay circuit connected to a charge / discharge output via first power lines; a power factor correction circuit connected to the relay circuit between the relay circuit and the battery via second power lines; a discharge output connected to branch lines branching from each of the second power lines; and a controller configured to control the relay circuit and the power factor correction circuit so as to supply power from the battery to an asymmetric current load or to a symmetric current load connected to the discharge output.The apparatus of claim 1, wherein: the second power lines comprise the (2-1)-th to (2-3)-th power lines; the branch lines comprise first to third branch lines respectively connected to the (2-1)-th to (2-3)-th power lines; and the discharge output comprises a positive (+) terminal connected to the first branch line, a negative (-) terminal connected to the second branch line, and a neutral terminal connected to the third branch line.The apparatus of claim 2, wherein a positive (+) voltage is applied to the (2-1)th power line, a negative (-) voltage is applied to the (2-2)th power line, and a zero voltage is applied to the (2-3)th power line.The device of claim 2, wherein the load using asymmetric power is connected to the positive (+) terminal and the neutral terminal.The device of claim 2, wherein the load using asymmetric power is connected to the negative (-) terminal and the neutral terminal.The device of claim 2, wherein the load using balanced power is connected to the positive (+) terminal, the negative (-) terminal, and the neutral terminal.The apparatus of claim 2, wherein: the relay circuit comprises: an L1 relay connected to the (2-1)th power line; an L1-L2 relay and an L2 relay connected in parallel to the (2-2)th power line; and an L3 relay and a neutral point relay connected in parallel to the (2-3)th power line; and the power factor correction circuit comprises: a first arm connected to the (2-1)th power line; a second arm connected to the (2-2)th power line; and a third arm connected to the (2-3)th power line.The apparatus according to claim 7, wherein in a case where the load using asymmetric power is connected to the discharge output, the controller is configured to: turn off the L1 relay, the L1-L2 relay, the L2 relay, the L3 relay, and the neutral point relay; and control the first to third branches so as to supply a positive (+) voltage to the (2-1)-th power line or a negative (-) voltage to the (2-2)-th power line.The apparatus according to claim 7, wherein in a case where the load using asymmetric power is connected to the discharge output, the controller is configured to: turn on the L1 relay, the L1-L2 relay, and the neutral point relay; turn off the relay L2 and the relay L3; and control the first to third branches so that a positive (+) voltage is applied to the (2-1)-th power line or a negative (-) voltage is applied to the (2-2)-th power line.The apparatus according to claim 9, wherein: the charge / discharge output comprises an L1 terminal connected to the L1 relay and the L1-L2 relay via a (1-1)-th power line, and a second neutral terminal connected to the neutral point relay via a (1-2)-th power line; and in a case where an out-of-vehicle load is connected to the L1 terminal and the second neutral terminal, the positive (+) voltage supplied to the (2-1)-th power line is supplied to the L1 terminal or the negative (-) voltage supplied to the (2-2)-th power line is supplied to the L1 terminal, so that power is simultaneously supplied to the load using asymmetric current and the out-of-vehicle load.The apparatus according to claim 7, wherein in a case where the load using balanced power is connected to the discharge output, the controller is configured to: turn off the L1 relay, the L1-L2 relay, the L2 relay, the L3 relay, and the neutral point relay; and perform pulse width modulation control on the first to third arms so that a positive (+) voltage is supplied to the (2-1)-th power line, a negative (-) voltage is supplied to the (2-2)-th power line, and a zero voltage is supplied to the (2-3)-th power line.The apparatus according to claim 7, wherein in a case where the load using balanced power is connected to the discharge output, the controller is configured to: turn on the L1 relay and the neutral point relay; turn off the L1-L2 relay, the L2 relay, and the L3 relay; and perform pulse width modulation control on the first to third arms so that a positive (+) voltage is applied to the (2-1)-th power line, a negative (-) voltage is applied to the (2-2)-th power line, and a zero voltage is applied to the (2-3)-th power line.The apparatus according to claim 12, wherein: the charge / discharge output comprises an L1 terminal connected to the L1 relay and the L1-L2 relay via the (1-1)-th power line, and a second neutral terminal connected to the neutral point relay via the (1-2)-th power line; and in a case where an out-of-vehicle load is connected to the L1 terminal and the second neutral terminal, the positive (+) voltage supplied to the (2-1)-th power line is supplied to the L1 terminal, and the zero voltage supplied to the (2-3)-th power line is supplied to the second neutral terminal, so that power is simultaneously supplied to the load using symmetric current and the out-of-vehicle load.A method of operating a power conversion device for electric vehicles, the method comprising: detecting whether an on-vehicle load is connected to a charge / discharge output or whether an on-vehicle load is connected to a discharge output; determining whether the on-vehicle load is a load using asymmetric power or a load using symmetric power, in response to determining that the on-vehicle load is connected to the discharge output; supplying the asymmetric power to the load using the asymmetric power, based on the power of a battery in a case where the on-vehicle load is the load using the asymmetric power; supplying the balanced power to the load using the balanced power based on the power of the battery in a case where the in-vehicle load is the load using the balanced power.The method according to claim 14, wherein the supplying the asymmetric power comprises supplying a positive (+) voltage and a zero voltage to the load using the asymmetric power in a case where the load using the asymmetric power is connected to a positive (+) terminal and a neutral terminal of the discharge output.The method according to claim 14, wherein the supplying the asymmetric power comprises supplying a negative (-) voltage and a zero voltage to the load using the asymmetric power in a case where the load using the asymmetric power is connected to a negative (-) terminal and a neutral terminal of the discharge output.The method of claim 14, wherein delivering the balanced power comprises delivering a positive (+) voltage, a negative (-) voltage, and a zero voltage to the load using the balanced power.The method according to claim 14, further comprising applying a positive (+) voltage and a zero voltage to the off-vehicle load and the load using the asymmetric power in a case where the off-vehicle load is connected to the charging / discharging output and the load using the asymmetric power is connected to the discharging output.The method of claim 14, further comprising applying a negative (-) voltage and a zero voltage to the off-board load and the load utilizing the asymmetric power in a case where the off-board load is connected to the charging / discharging output and the load utilizing the asymmetric power is connected to the discharging output.The method according to claim 14, further comprising supplying a positive (+) voltage and a zero voltage to the off-vehicle load, and supplying the positive (+) voltage, a negative (-) voltage and the zero voltage to the load using the balanced power in a case where the off-vehicle load is connected to the charge / discharge output and the load using the balanced power is connected to the discharge output.