Electric vehicle on-board charger, relay control method and bidirectional charging system

Abstract

The present disclosure relates to an electric vehicle on-board charger, a relay control method of the electric vehicle on-board charger, and an electric vehicle two-way charging system including the electric vehicle on-board charger, the electric vehicle on-board charger including: a vehicle port configured to be connected to an external charger, the external charger includes a first relay located on an internal first power supply path; a power converter; a second relay located on a second power supply path between the vehicle port and the power converter; and a controller configured to open the first relay and the second relay in response to triggering a vehicle-to-grid (V2G) protection operation based on the power-related parameter.

Description

Technical Field

[0001] The present invention relates to an on-board charger for an electric vehicle. Background Art

[0002] Vehicle to Grid (V2G) refers to the function of supplying electricity to the grid power unit using the high-voltage battery of an electric vehicle. The advantage of using V2G is that consumers can obtain additional benefits through electricity sales, and electricity sellers can store electricity in the high-voltage battery of the vehicle (or vehicle battery) and use the electricity effectively, thereby actually using the vehicle as an electric storage system (ESS).

[0003] V2G can be achieved through communication between the on-board charger (OBC) (or bidirectional slow charger), the vehicle charge management system (VCMS) and the electric vehicle supply equipment (EVSE).

[0004] The VCMS communicates with the EVSE to determine V2G operation, and the OBC supplies power to the grid using the vehicle battery.

[0005] For safety reasons related to V2G, Ns protection (network and system protection) is mandatory by law.

[0006] There are relays for current cutoff between the vehicle battery and the grid, so that one relay is located in the vehicle and one relay is located in the EVSE.

[0007] V2G requires fault diagnosis and relay disconnection within a short time (maximum 90ms), but it is difficult for EVSE, which only serves as a simple charger, to perform fast fault diagnosis and relay disconnection.

[0008] In addition, to prevent misdiagnosis, the relay that plays a major role (main relay) should be disconnected first, and then the relay that plays an auxiliary role (auxiliary relay) should be disconnected. Therefore, an appropriate control method for two independent relays is required.

[0009] This background information possessed by the inventors in developing the present disclosure or obtained during the development of the present disclosure is not necessarily known art disclosed to the public before filing the present disclosure. Summary of the invention

[0010] The present disclosure relates to an electric vehicle OBC, and in a particular embodiment, to an electric vehicle OBC capable of quickly determining and controlling the operation of a relay in the OBC and a relay in an external charger, a relay control method for the electric vehicle OBC, and an electric vehicle bidirectional charging system including the electric vehicle OBC.

[0011] The embodiments disclosed in the present disclosure can address the above-mentioned needs and can provide an electric vehicle OBC that can quickly determine and control the operation of relays in the OBC and relays in an external charger, a relay control method for the electric vehicle OBC, and an electric vehicle bidirectional charging system including the electric vehicle OBC.

[0012] The technical subject matter of the present disclosure may not be limited to the above-mentioned technical subject matter, and those skilled in the art to which the present disclosure belongs may clearly understand other technical subject matters involved in the present disclosure through the following description.

[0013] As a technical approach to achieve the above technical tasks, an electric vehicle OBC that can quickly determine and control the operation of relays in the OBC and relays in an external charger, a relay control method for the electric vehicle OBC, and an electric vehicle bidirectional charging system including the electric vehicle OBC can be provided.

[0014] An electric vehicle OBC according to an embodiment of the present disclosure may include: a vehicle port connected to an external charger, the external charger including a first relay located on an internal first power supply path; a second relay located on a second power supply path between the vehicle port and a power converter; and a controller configured to disconnect the first relay and the second relay if it is determined based on power-related parameters that a V2G (vehicle to grid) protection operation is required.

[0015] According to an embodiment, the controller may directly turn off the second relay and output a relay turn-off signal for turning off the first relay to the external charger.

[0016] According to an embodiment, the relay off signal may be a control pilot (CP) signal having a relay off voltage level, and the controller may output the CP signal to the external charger through a CP line.

[0017] According to an embodiment, in a case where the first relay is configured as a main relay, the controller may turn off the second relay after outputting a relay turn-off signal to the external charger.

[0018] According to an embodiment, in a case where the second relay is configured as a main relay, the controller may output a relay disconnection signal to the external charger after disconnecting the second relay.

[0019] According to an embodiment, the electric vehicle OBC may include a CP signal output unit located between a CP line and a ground and configured to output a CP signal under the control of a controller.

[0020] According to an embodiment, the CP signal output unit may include: two resistors located in parallel between the CP line and the ground; and a switch located between one of the two resistors and the ground, and the controller may control the switch to control the voltage level of the CP signal output from the CP signal output unit.

[0021] According to an embodiment, the controller may transmit relay disconnection information indicating that the V2G protection operation has been performed to the external charger before disconnecting the second relay.

[0022] According to an embodiment, the controller may compare a power-related parameter value obtained during operation with pre-stored V2G diagnostic parameter information, and determine that a V2G protection operation is required if the obtained power-related parameter value falls outside an allowable range included in the V2G diagnostic parameter information.

[0023] A relay control method for an electric vehicle OBC according to an embodiment of the present disclosure may include: determining whether a V2G (vehicle to grid) protection operation is required based on power-related parameters obtained when performing the operation; and if it is determined that a V2G protection operation is required, disconnecting a first relay and a second relay, the first relay being located on a first power supply path in an external charger connected to the OBC, and the second relay being located on a second power supply path inside the OBC.

[0024] According to an embodiment, the disconnecting may include directly disconnecting the second relay and outputting a relay disconnection signal for disconnecting the first relay to the external charger.

[0025] According to an embodiment, the relay off signal may be a CP signal having a relay off voltage level, and the off may include outputting the CP signal to the external charger through a CP line.

[0026] According to an embodiment, the disconnecting may include, in a case where the first relay is configured as a main relay, disconnecting the second relay after outputting a relay disconnection signal to the external charger.

[0027] According to an embodiment, the disconnecting may include, in a case where the second relay is configured as a main relay, outputting a relay disconnection signal to the external charger after disconnecting the second relay.

[0028] According to an embodiment, the disconnecting may further include: transmitting relay disconnection information indicating that the V2G protection operation has been performed to the external charger before disconnecting the second relay.

[0029] According to an embodiment, the determination may include: comparing a power-related parameter value obtained during operation with pre-stored V2G diagnostic parameter information; and determining that a V2G protection operation is required if the obtained power-related parameter value falls outside an allowable range included in the V2G diagnostic parameter information.

[0030] According to an embodiment, the relay control method of the OBC may include receiving and storing V2G diagnostic parameter information from an external charger before the determining.

[0031] An electric vehicle bidirectional charging system according to an embodiment of the present disclosure may include: an external charger, including a first relay located on a first power supply path; and an OBC, including a second relay located on a second power supply path, and if it is determined based on power-related parameters obtained when performing the operation that a V2G (vehicle to grid) protection operation is required, the OBC may disconnect the first relay and the second relay.

[0032] According to an embodiment, the external charger may transmit V2G diagnostic parameter information to the OBC before the V2G operation, and the OBC may receive and store the V2G diagnostic parameter information transmitted from the external charger.

[0033] According to an embodiment of the present disclosure, an electric vehicle OBC capable of quickly determining and controlling the operation of a relay in the OBC and a relay in an external charger, a relay control method of the electric vehicle OBC, and an electric vehicle bidirectional charging system including the electric vehicle OBC may be provided.

[0034] According to the embodiment, since the OBC determines whether the relay in the external charger (EVSE) operates as well as whether the relay in the OBC operates, it may be determined more quickly whether the relay operates than when the external charger determines whether the relay in the external charger operates.

[0035] According to the embodiment, since control of a relay in an external charger is performed through modulation of a CP signal without using a communication method such as a controller area network (CAN), the relay in the external charger may be quickly controlled.

[0036] According to an embodiment, the OBC may preferentially perform a disconnection operation of the main relay among the relay in the external charger and the relay in the OBC.

[0037] If the OBC preferentially disconnects the relay in the external charger as described above, the OBC can notify the external charger that the Ns protection has been performed, thereby preventing the external charger from misdiagnosing the relay.

[0038] Advantages of the present disclosure may not be limited to the above advantages, and those skilled in the art to which the present disclosure belongs may also clearly understand other advantages that are not mentioned through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings and detailed description are provided to aid in understanding the embodiments of the present disclosure, wherein:

[0040] Figure 1 is an overall conceptual diagram of a V2G infrastructure using an electric vehicle bidirectional charging system according to an embodiment of the present disclosure;

[0041] Figure 2 is a diagram showing a detailed configuration of an external charger such as electric vehicle supply equipment (EVSE) of an electric vehicle bidirectional charging system according to an embodiment of the present disclosure;

[0042] Figure 3 is a diagram showing a configuration of an on-board charger (OBC) of an electric vehicle bidirectional charging system according to an embodiment of the present disclosure;

[0043] Figure 4 is a diagram illustrating a relay control method of an electric vehicle bidirectional charging system according to an embodiment of the present disclosure; and

[0044] Figure 5 is a diagram illustrating a relay control method of an electric vehicle bidirectional charging system according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0045] By referring to the embodiments described in detail below in conjunction with the accompanying drawings, the advantages and features of the present disclosure and the methods for achieving these advantages and features may become apparent. However, the present disclosure is not limited to the embodiments set forth below and may be implemented in various different forms. The following embodiments are provided to enable those skilled in the art to understand the scope of the present disclosure.

[0046] The shapes, sizes, ratios, angles and quantities disclosed in the accompanying drawings for explaining the embodiments of the present disclosure are provided only by way of example, and therefore the present disclosure is not limited to the shapes, sizes, ratios, angles and quantities shown in the accompanying drawings. Throughout the specification, the same or similar reference numerals may refer to the same or similar elements. In addition, when describing the present disclosure, when it is determined that the detailed description of the known related art unnecessarily obscures the subject matter of the present disclosure, the detailed description may be omitted. In the case of using the expressions "comprising", "having" and "including" in the specification, other parts may be added unless the term "only" is used. Unless otherwise expressly stated, elements expressed in the singular may include plural forms.

[0047] When interpreting an element, even if there is no explicit description of the error range, the element can be interpreted as covering the error range.

[0048] In describing a temporal relationship, when words such as “after,” “subsequently,” “next,” or “before” are used to describe the temporal order, the temporal order may include discontinuous cases unless the terms “just after” or “immediately” are used.

[0049] The terms "first", "second", etc. may be used to describe various elements, but these elements are not necessarily limited by these terms. These terms may only be used to distinguish one element from other elements. Therefore, without departing from the spirit of the present disclosure, the first element used in the following description may be the second element.

[0050] When describing elements of the present disclosure, terms such as "first", "second", "A", "B", "(a)", and "(b)" may be used. These terms may be used only to distinguish the corresponding elements from other elements, and the nature, order, sequence, or number of the corresponding elements are not necessarily limited by these terms. It will be understood that when an element is referred to as being "connected to" or "coupled to" another element, the element may be directly connected to or coupled to the other element, but another element may be interposed between elements that may be indirectly connected or coupled to each other.

[0051] The term "at least one" should be understood to include any or all combinations of one or more of the listed related elements. For example, "at least one of a first element, a second element, and a third element" may refer not only to the first element, the second element, or the third element, but also to all combinations of two or more of the first element, the second element, and the third element.

[0052] The various features of the various embodiments of the present disclosure may be partially or completely combined or combined with each other and may be technically linked and interoperable with each other in various ways, and the various embodiments of the present disclosure may be implemented independently of each other or may be implemented in association with each other.

[0053] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings and the embodiments described herein. For the convenience of description, the proportions of the elements shown in the drawings may be different from the actual proportions, and thus the elements are not limited by the proportions shown in the drawings.

[0054] Hereinafter, an electric vehicle OBC, a relay control method of the electric vehicle OBC, and an electric vehicle bidirectional charging system including the electric vehicle OBC according to embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0055] Figure 1 is an overall conceptual diagram of a V2G infrastructure to which an electric vehicle bidirectional charging system according to an embodiment of the present disclosure is applied.

[0056] Reference Figure 1 , the infrastructure to which the electric vehicle bidirectional charging system according to an embodiment of the present disclosure is applied includes a power system (grid) G, an external charger (eg, electric vehicle supply equipment) (EVSE) 100, and an on-board charger (OBC) 200 in the electric vehicle EV.

[0057] The power system G may be provided by a power supply company, and may include, for example, a power plant, a substation, power cables, etc. For example, the power system G may be a smart grid.

[0058] The power system G may supply power to or receive power from a consumer. For example, the power system G may supply power to or receive power from an electric vehicle EV through an external charger 100 .

[0059] The external charger 100 can supply the electric vehicle EV with the electric power supplied from the electric power system G. In addition, the external charger 100 can supply the electric power supplied from the electric vehicle EV to the electric power system G.

[0060] For example, the external charger 100 may supply power to the electric vehicle EV through the cable C or receive power from the electric vehicle EV.

[0061] The external charger 100 according to the embodiment provides external charger related diagnostic parameter information (hereinafter referred to as V2G diagnostic parameter information) to the onboard charger 200 of the electric vehicle EV. The external charger 100 may provide the onboard charger 200 with the V2G diagnostic parameter information before the V2G operation.

[0062] The V2G diagnostic parameter information may include a standard range of parameters used by the on-board charger 200 to diagnose the status of the external charger 100 .

[0063] For example, the V2G diagnostic parameter information may include an allowable voltage range, an allowable current range, and an allowable frequency range for normal operation of the external charger 100 .

[0064] According to an embodiment, the external charger 100 may use vehicle-related communication to provide V2G diagnostic parameter information to the on-board charger 200. For example, the external charger 100 may use a communication scheme such as a controller area network (CAN), a local interconnect network (LIN), a power line communication (PLC), a pulse width modulation (PWM), etc. to provide V2G diagnostic parameter information to the on-board charger 200.

[0065] The external charger 100 according to the embodiment may receive the relay disconnection signal from the onboard charger 200 and disconnect the onboard relay (first relay or charger relay). According to the embodiment, the external charger 100 may receive the relay disconnection signal through a control pilot (CP) line included in the cable C.

[0066] In addition, when the relay disconnection information is received from the on-board charger 200, the external charger 100 may respond thereto by displaying that the relay disconnection has been performed by the V2G protection function. According to an embodiment, for example, the external charger 100 may receive the relay disconnection information from the on-board charger 200 using vehicle-related communications such as CAN, LIN, PLC, PWM, etc.

[0067] The on-vehicle charger 200 may be mounted on an electric vehicle EV, and may control charging and discharging of a high-voltage battery (hereinafter referred to as a vehicle battery) mounted to the electric vehicle EV.

[0068] The on-vehicle charger 200 can charge the vehicle battery using the power supplied from the external charger 100 (charging mode). The on-vehicle charger 200 can supply the power of the vehicle battery to the external charger 100 (discharging mode).

[0069] According to an embodiment, the on-board charger 200 may receive the V2G diagnostic parameter information from the external charger 100 and store the received V2G diagnostic parameter information.

[0070] While performing the V2G operation, the on-board charger 200 may obtain a parameter value related to power supplied from the external charger 100 or a parameter value related to power supplied to the external charger 100 .

[0071] According to an embodiment, the on-board charger 200 may obtain values ​​of voltage, current, and frequency related to electric power.

[0072] The onboard charger 200 may compare the obtained parameter value with the stored V2G diagnostic parameter information and determine whether to disconnect the relay.

[0073] According to an embodiment, the on-board charger 200 may compare the obtained voltage value, current value, and frequency with a pre-stored allowable voltage range, allowable current range, and allowable frequency range to determine whether to disconnect the relay.

[0074] If the obtained parameter value falls outside the corresponding allowable range, the on-board charger 200 may perform a relay disconnection operation.

[0075] According to an embodiment, the onboard charger 200 may perform an operation of disconnecting a relay (a second relay or a vehicle relay) installed therein. In addition, the onboard charger 200 may perform an operation of disconnecting a relay (a first relay or a charger relay) inside the external charger 100.

[0076] The on-board charger 200 may directly turn off the second relay and output a relay turn-off signal to the external charger 100 to turn off the first relay.

[0077] According to an embodiment, the on-board charger 200 may output a relay disconnection signal to the external charger 100 after disconnecting the second relay.

[0078] According to an embodiment, the onboard charger 200 may output a relay disconnection signal to the external charger 100 and then disconnect the second relay. In this case, the onboard charger 200 may output relay disconnection information to the external charger 100 before disconnecting the second relay.

[0079] The on-vehicle charger 200 may sequentially output the relay disconnection signal and the relay disconnection information to the external charger 100 and then disconnect the second relay.

[0080] Figure 2 is a diagram showing a detailed configuration of an external charger 100 (electric vehicle supply equipment (EVSE)) of the electric vehicle bidirectional charging system according to an embodiment of the present disclosure. Figure 3 is a diagram showing a configuration of an on-board charger (OBC) 200 of an electric vehicle bidirectional charging system according to an embodiment of the present disclosure.

[0081] Reference Figures 1 to 3 The external charger 100 according to the embodiment may include a first relay (Relay_1 or R_1) 110, a charger / discharger 120, a first communication unit 130, a vehicle connection unit 140, a first controller 150, and a display unit 160, and the configuration of the external charger 100 is not necessarily limited thereto.

[0082] The first relay 110 may be located between a power system connection terminal T_G (connected to the power system G) and the charger / discharger 120 , and may receive power supplied from the power system G through the power system connection terminal T_G and provide the power to the charger / discharger 120 .

[0083] In addition, the first relay 110 may provide the power supplied from the on-board charger 200 of the electric vehicle EV to the power system G through the power system connection terminal T_G.

[0084] A first power supply path may be defined between the power system connection terminal T_G and the charger / discharger 120 .

[0085] According to an embodiment, the first relay 110 may be operated to be closed or opened under the control of the first controller 150. In a state where the first relay 110 is closed, the first relay 110 may supply power from the power system G to the charger / discharger 120 or supply power from the charger / discharger 120 to the power system G.

[0086] The charger / discharger 120 may convert power supplied through the first relay 110 into battery charging power and output the converted power. The charger / discharger 120 may convert power supplied from the electric vehicle EV into power system power and output the converted power.

[0087] For example, the charger / discharger 120 may output battery charging power to the vehicle connection unit 140 and receive power supplied from the electric vehicle EV through the vehicle connection unit 140 .

[0088] For example, the charger / discharger 120 may be connected to the cable connection portion 141 of the vehicle connection unit 140 to supply battery charging power to the electric vehicle EV through the cable C or receive power supplied from the electric vehicle EV through the cable C and the cable connection portion 141 .

[0089] The first communication unit 130 may be configured to communicate with the on-board charger 200 of the electric vehicle EV, and may transmit information transmitted from the first controller 150 to the on-board charger 200 and may receive information transmitted from the on-board charger 200 and forward the information to the first controller 150 .

[0090] According to an embodiment, the first communication unit 130 may transmit the V2G diagnostic parameter information to the on-board charger 200 and receive the relay disconnection information from the on-board charger 200 .

[0091] For example, the first communication unit 130 may communicate with the vehicle charger 200 using a vehicle-related communication scheme such as CAN, LIN, PLC, PWM, or the like.

[0092] The vehicle connection unit 140 may be connected to a vehicle port of the electric vehicle EV to electrically connect the external charger 100 and the electric vehicle EV.

[0093] According to an embodiment, the vehicle connection unit 140 may include a cable connection portion 141 , a cable C, and a connector 142 .

[0094] One end of the cable connection portion 141 may be installed in the external charger 100 , and the other end of the cable connection portion 141 may be connected to the cable C.

[0095] One end of the cable connection portion 141 may be electrically connected to the first controller 150 through the internal line IL, and forward a CP signal input through the CP line CPL1 located inside the cable C to the first controller 150 .

[0096] The connector 142 may be connected to the other end of the cable connection portion 141 and may be connected to a vehicle port of the electric vehicle EV.

[0097] In a case where the connector 142 is connected to a vehicle port of an electric vehicle EV, the connector 142 may be electrically connected to an onboard charger 200 of the electric vehicle EV and may serve as a medium for transmitting power or signals between the external charger 100 and the electric vehicle EV.

[0098] The first controller 150 may control the overall operation of the external charger 100 , and enable the external charger 100 to supply power supplied from the electric system G to the electric vehicle EV and to supply power supplied from the electric vehicle EV to the electric system G.

[0099] The first controller 150 may provide the electric vehicle EV with V2G diagnostic parameter information related to the external charger 100. For example, the first controller 150 may provide the electric vehicle EV with V2G diagnostic parameter information before the V2G operation.

[0100] For example, the first controller 150 may provide the V2G diagnostic parameter information to the electric vehicle EV through the first communication unit 130 .

[0101] The first controller 150 may perform control of the first relay 110 based on the CP signal transmitted from the electric vehicle EV.

[0102] For example, the CP signal may be transmitted to the cable connection portion 141 through the CP line CPL1 in the cable C, and then input to the first controller 150 through the internal line IL.

[0103] According to an embodiment, the first controller 150 may control the first relay 110 based on the voltage level of the CP signal. For example, the first controller 150 may determine whether the voltage level of the CP signal falls within a preset relay disconnection voltage range, and disconnect the first relay 110 if the voltage level of the CP signal falls within the relay disconnection voltage range.

[0104] As described above, since the first controller 150 controls the first relay 110 based on the CP signal transmitted through the CP line CPL1 , the first relay 110 may be quickly controlled.

[0105] When receiving the relay disconnection information provided from the electric vehicle EV, the first controller 150 may display on the display unit 160 that the relay disconnection has been performed by the V2G protection function in response thereto.

[0106] For example, the first controller 150 may receive the relay disconnection information through the first communication unit 130 .

[0107] The on-board charger 200 according to the embodiment may include a vehicle port 210 , a second relay (Relay_2 or R_2 ) 220 , a power converter 230 , a second communication unit 240 , a CP signal output unit 250 , and a second controller 260 , and the configuration of the on-board charger 200 is not necessarily limited thereto.

[0108] The vehicle port 210 may be connected to the vehicle connection unit 140 of the external charger 100 , receive power from the external charger 100 , and provide power from the power converter 230 to the external charger 100 through the vehicle connection unit 140 .

[0109] Since the vehicle port 210 may be connected to the vehicle connection unit 140 , a CP line (or a first CP line) CPL1 of the vehicle connection unit 140 and a CP line (or a second CP line) CPL2 of the OBC 200 may be connected to each other.

[0110] The second relay 220 may be located between the vehicle port 210 and the power converter 230 , provide power supplied through the vehicle port 210 to the power converter 230 , and provide power from the power converter 230 to the vehicle port 210 .

[0111] A second power supply path may be defined between the vehicle port 210 and the power converter 230 .

[0112] According to an embodiment, the second relay 220 may be operated to be closed or opened under the control of the second controller 260. In a state where the second relay 220 is closed, the second relay 220 may provide power from the vehicle port 210 to the power converter 230 or provide power from the power converter 230 to the vehicle port 210.

[0113] The power converter 230 may convert the power supplied through the second relay 220 into power for the high voltage battery of the electric vehicle EV and output the converted power. The power converter 230 may convert the power supplied from the high voltage battery of the electric vehicle EV into power system power and output the converted power.

[0114] The second communication unit 240 may be configured to communicate with the external charger 100 , and may transmit information transmitted from the second controller 260 to the first communication unit 130 of the external charger 100 , and may receive information transmitted from the first communication unit 130 of the external charger 100 and forward the information to the second controller 260 .

[0115] According to an embodiment, the second communication unit 240 may transmit the relay disconnection information to the first communication unit 130 of the external charger 100 , and receive the V2G diagnosis parameter information from the first communication unit 130 of the external charger 100 .

[0116] For example, the second communication unit 240 may communicate with the first communication unit 130 of the external charger 100 using a vehicle-related communication scheme such as CAN, LIN, PLC, PWM, or the like.

[0117] The CP signal output unit 250 may output the CP signal to a CP line (or a second CP line) CPL2 of the OBC 200 .

[0118] The CP signal output from the CP signal output unit 250 may be transmitted along the second CP line CPL2 and the first CP line CPL1 of the vehicle connection unit 140 connected to the vehicle port 210 , and then input to the first controller 150 of the external charger 100 .

[0119] According to an embodiment, the CP signal output unit 250 may output the CP signal in response to the control of the second controller 260 .

[0120] The CP signal output unit 250 may output a CP signal having a first voltage level (or a relay opening voltage level) or a CP signal having a second voltage level (or a relay closing voltage level) in response to the control of the second controller 260 .

[0121] According to an embodiment, the CP signal output unit 250 may include two resistors R1 and R2 located in parallel between the second CP line CPL2 and the ground, and the switch SW may be connected in series to one of the two resistors R1 and R2. In an embodiment, the switch SW may be connected in series with the second resistor R2.

[0122] The switch SW of the CP signal output unit 250 may be closed or opened in response to the control of the second controller 260 , and the output voltage of the CP signal output unit 250 varies according to the state of the switch SW.

[0123] For example, if the switch SW is closed, the CP signal output unit 250 may output a CP signal having a first voltage level (or a relay open voltage level), and if the switch SW is open, the CP signal output unit 250 may output a CP signal having a second voltage level (or a relay closed voltage level).

[0124] The second controller 260 may receive the V2G diagnostic parameter information provided from the external charger 100 and store the received V2G diagnostic parameter information.

[0125] When performing the V2G operation, the second controller 260 may obtain values ​​of parameters (e.g., voltage, current, frequency, etc.) related to power provided from the external charger 100 or values ​​of parameters (e.g., voltage, current, frequency, etc.) related to power supplied to the external charger 100 .

[0126] For example, the second controller 260 may obtain a parameter value related to power on the second power supply path between the vehicle port 210 and the power converter 230 .

[0127] The second controller 260 may compare the obtained parameter value with the stored V2G diagnostic parameter information and determine whether to turn off the relay.

[0128] According to an embodiment, the second controller 260 may compare the obtained voltage value, current value, and frequency with a pre-stored allowable voltage range, allowable current range, and allowable frequency range to determine whether to disconnect the relay.

[0129] If any one of the obtained parameter values ​​falls outside the corresponding allowable range, the second controller 260 may perform a relay disconnecting operation.

[0130] According to an embodiment, the second controller 260 may perform an operation of turning off the second relay. In addition, the second controller 260 may perform an operation of turning off the first relay inside the external charger 100.

[0131] Here, the second controller 260 may directly turn off the second relay 220 and control the CP signal output unit 250 to output a CP signal having a first voltage level (or a relay-off voltage level) to the external charger 100 to turn off the first relay 110 .

[0132] According to the setting, the second controller 260 may turn off the second relay 220 and then control the CP signal output unit 250 to output the CP signal having the first voltage level (or the relay-off voltage level) to the external charger 100 .

[0133] According to the setting, the second controller 260 may control the CP signal output unit 250 to output the CP signal having the first voltage level (or the relay disconnection voltage level) to the external charger 100, and then disconnect the second relay 220. In this case, the second controller 260 may output the relay disconnection information to the external charger 100 through the second communication unit 240 before disconnecting the second relay 220.

[0134] Figure 4 is a diagram illustrating a relay control method of an electric vehicle bidirectional charging system according to an embodiment of the present disclosure.

[0135] Figure 4The relay control method of the electric vehicle bidirectional charging system shown is performed in the following case: the entity of the V2G Ns protection operation is configured as the external charger 100, so that the first relay 110 in the external charger 100 acts as a main relay, and the second relay 220 in the vehicle charger 200 acts as an auxiliary relay.

[0136] Therefore, according to Figure 4 The relay control method of the electric vehicle bidirectional charging system shown is to disconnect the first relay 110 first and then disconnect the second relay 220 .

[0137] Reference Figures 1 to 4 , the external charger 100 may provide the V2G diagnostic parameter information to the on-board charger 200 (operation S400 ), and accordingly, the on-board charger 200 may receive the V2G diagnostic parameter information (operation S410 ).

[0138] The V2G diagnostic parameter information may include an allowable voltage range, an allowable current range, an allowable frequency range, and the like.

[0139] Thereafter, the on-board charger 200 may determine whether to perform an Ns protection operation (operation S430 ) when performing a V2G (Vehicle to Grid) operation (operation S420 ).

[0140] In operation S420 , the onboard charger 200 may obtain values ​​of power-related parameters (eg, voltage, current, frequency, etc.) while performing the V2G operation.

[0141] In operation S430 , the onboard charger 200 may compare the obtained power-related parameter value with the V2G diagnostic parameter information and determine whether the obtained parameter value falls outside a permissible range.

[0142] If it is determined in operation S430 that the V2G protection operation does not need to be performed (“No” at operation S430 ), that is, if it is determined that the obtained parameter value falls within the allowable range, the on-board charger 200 may perform operation S420 .

[0143] In operation S430 , if at least one of the obtained values ​​of the plurality of parameters (voltage, current, and frequency) falls outside the allowable range, the on-board charger 200 may determine that a V2G protection operation is to be performed.

[0144] If it is determined in operation S430 that the V2G protection operation is to be performed (“YES” at operation S430 ), the onboard charger 200 may output a signal (“relay disconnection signal”) for disconnecting the first relay 110 in the external charger 100 to the external charger 100 (operation S440 ).

[0145] In operation S440 , the relay off signal may be a CP signal having a relay off voltage level.

[0146] The external charger 100 may turn off the first relay 110 in response to the relay turn-off signal (operation S450 ).

[0147] Thereafter, the onboard charger 200 may transmit relay disconnection information indicating that relay disconnection has been performed through the V2G protection operation to the external charger 100 (operation S460 ).

[0148] When the relay disconnection information is received, the external charger 100 may display through the display unit 160 that the V2G protection operation has been performed (operation S470 ).

[0149] Thereafter, the on-board charger 200 may turn off the second relay 220 (operation S480 ).

[0150] Figure 5 is a diagram illustrating a relay control method of an electric vehicle bidirectional charging system according to an embodiment of the present disclosure.

[0151] Figure 5 The relay control method of the electric vehicle bidirectional charging system shown can be performed in the following case: the entity of the V2GNs protection operation is configured as the on-board charger 200, so that the second relay 220 in the on-board charger 200 acts as the main relay, and the first relay 110 in the external charger 100 acts as the auxiliary relay.

[0152] Therefore, according to Figure 5 The relay control method of the electric vehicle bidirectional charging system shown is to disconnect the second relay 220 first and then disconnect the first relay 110 .

[0153] Reference Figures 1 to 3 as well as Figure 5 , the external charger 100 may provide the V2G diagnostic parameter information to the on-board charger 200 (operation S500 ), and accordingly, the on-board charger 200 may receive the V2G diagnostic parameter information (operation S510 ).

[0154] For example, the V2G diagnostic parameter information may include an allowable voltage range, an allowable current range, an allowable frequency range, and the like.

[0155] Thereafter, the on-board charger 200 may determine whether to perform an Ns protection operation (operation S530 ) when performing a V2G (Vehicle to Grid) operation (operation S520 ).

[0156] In operation S520 , the onboard charger 200 may obtain values ​​of power-related parameters (eg, voltage, current, frequency, etc.) while performing the V2G operation.

[0157] In operation S530 , the onboard charger 200 may compare the obtained power-related parameter value with the V2G diagnostic parameter information and determine whether the obtained parameter value falls outside the allowable range.

[0158] If it is determined in operation S530 that the V2G protection operation does not need to be performed (“NO” at operation S530 ), that is, if it is determined that the obtained parameter value falls within the allowable range, the on-board charger 200 may perform operation S520 .

[0159] In operation S530 , if at least one of the obtained values ​​of the plurality of parameters (voltage, current, and frequency) falls outside the allowable range, the on-board charger 200 may determine that a V2G protection operation is to be performed.

[0160] If it is determined in operation S530 that the V2G protection operation is to be performed (“YES” at operation S530 ), the on-board charger 200 may disconnect the second relay 220 (operation S540 ).

[0161] Thereafter, the on-board charger 200 may output a signal (“relay disconnection signal”) for disconnecting the first relay 110 in the external charger 100 to the external charger 100 (operation S550 ).

[0162] In operation S550 , the relay off signal may be a CP signal having a relay off voltage level.

[0163] Thereafter, the external charger 100 may turn off the first relay 110 in response to the relay turn-off signal (operation S560 ).

[0164] Although the embodiments of the present disclosure have been described above with reference to the accompanying drawings, the present disclosure is not necessarily limited to these embodiments, and various modifications and changes may be made to these embodiments without departing from the technical ideas of the present disclosure. Therefore, the embodiments disclosed herein are not necessarily intended to limit the technical ideas of the present disclosure, but are intended to explain the technical ideas of the present disclosure, and the scope of the technical ideas of the present disclosure is not necessarily limited by these embodiments. Therefore, the embodiments described above may be interpreted as illustrative rather than restrictive. The scope of protection of the present disclosure shall be defined by the attached claims, and all technical ideas equivalent to the claims may be deemed to fall within the scope of protection of the present disclosure.

Claims

1. An onboard charger for an electric vehicle, comprising: a vehicle port connected to an external charger, the external charger including a first relay located on an internal first power supply path; Power converters; a second relay located on a second power supply path between the vehicle port and the power converter; as well as A controller is configured to open the first relay and the second relay in response to triggering a vehicle-to-grid protection operation (V2G protection operation) based on power-related parameters.

2. The vehicle charger according to claim 1, wherein: The controller is configured to directly turn off the second relay and output a relay turn-off signal for turning off the first relay to the external charger.

3. The vehicle charger according to claim 2, wherein: The relay disconnection signal includes a control pilot signal (CP signal) having a relay disconnection voltage level, and The controller is configured to output the CP signal to the external charger through a CP line.

4. The vehicle charger according to claim 2, wherein: The controller is configured to turn off the second relay after outputting the relay turn-off signal to the external charger, wherein the first relay is configured as a main relay.

5. The vehicle charger according to claim 2, wherein: The controller is configured to output the relay-off signal to the external charger after turning off the second relay, wherein the second relay is configured as a main relay.

6. The vehicle charger according to claim 3, comprising: The CP signal output unit is located between the CP line and the ground, and outputs the CP signal under the control of the controller.

7. The vehicle charger according to claim 6, wherein: The CP signal output unit comprises: two resistors, arranged in parallel between the CP line and the ground; and A switch is serially connected between one of the two resistors and the ground, and the controller is configured to control the switch to control a voltage level of the CP signal output from the CP signal output unit.

8. The vehicle charger according to claim 4, wherein: The controller is configured to transmit relay disconnection information indicating that the V2G protection operation has been performed to the external charger before disconnecting the second relay.

9. The vehicle charger according to claim 1, wherein: The controller is configured to compare a power-related parameter value obtained during operation with pre-stored V2G diagnostic parameter information, and trigger the V2G protection operation in response to the obtained power-related parameter value falling outside an allowable range included in the V2G diagnostic parameter information.

10. A relay control method for an on-board charger of an electric vehicle, namely, a relay control method for an electric vehicle OBC, comprising: determining whether to trigger a vehicle-to-grid protection operation, i.e., a V2G protection operation, based on power-related parameters obtained when performing the operation; as well as In response to determining that the V2G protection operation is triggered, a first relay and a second relay are opened, wherein the first relay is located on a first power supply path in an external charger connected to the OBC, and the second relay is located on a second power supply path inside the OBC.

11. The method according to claim 10, wherein: The disconnection includes: directly disconnecting the second relay and outputting a relay disconnection signal for disconnecting the first relay to the external charger.

12. The method according to claim 11, wherein: The relay disconnection signal is a control pilot signal, i.e., a CP signal, having a relay disconnection voltage level, and The disconnecting includes: outputting the CP signal to the external charger through a CP line.

13. The method according to claim 11, wherein: The disconnection includes disconnecting the second relay after outputting the relay disconnection signal to the external charger when the first relay is configured as a main relay.

14. The method according to claim 13, wherein: Disconnecting further includes: transmitting relay disconnection information indicating that the V2G protection operation has been performed to the external charger before disconnecting the second relay.

15. The method according to claim 11, wherein: The disconnecting includes: when the second relay is configured as a main relay, outputting the relay disconnection signal to the external charger after disconnecting the second relay.

16. The method according to claim 10, wherein: Make sure to include: comparing power-related parameter values ​​obtained during operation with pre-stored V2G diagnostic parameter information; and When the obtained power-related parameter value falls outside the allowable range included in the V2G diagnostic parameter information, it is determined that the V2G protection operation is triggered.

17. The method according to claim 10, comprising: V2G diagnostic parameter information is received and stored from the external charger prior to the determining.

18. An electric vehicle bidirectional charging system, comprising: an external charger, the external charger comprising a first relay located on a first power supply path in the external charger; as well as an on-board charger (OBC), the OBC comprising a second relay located on a second power supply path in the OBC, and The OBC disconnects the first relay and the second relay in response to determining that a vehicle-to-grid protection operation (V2G protection operation) is required based on power-related parameters obtained when performing the operation.

19. The system of claim 18, wherein: The OBC directly turns off the second relay and outputs a relay turning off signal for turning off the first relay to the external charger.

20. The system of claim 18, wherein: The external charger transmits V2G diagnostic parameter information to the OBC, and The OBC receives and stores the V2G diagnostic parameter information transmitted from the external charger.

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