Apparatus for controlling isolation charging of vehicle, system having the same, and method thereof

This application claims the benefit of priority to Korean Patent Application No. 10-2018-0156551, filed in the Korean Intellectual Property Office on Dec. 7, 2018 the entire contents of which are incorporated herein by reference.

The present disclosure relates to an isolation charging control apparatus of a vehicle and a system having the same.

The plug-in hybrid vehicle (PHEV) and the electric vehicle (EV) are charged from an external power source, and are driven by the charged power.

As such, a power line, a control pilot (CP) line and a proximity detection (PD) line are connected to a vehicle, for the purpose of charging from the electric vehicle supply equipment (EVSE) of the external charging station.

When charging an electric vehicle, the electric vehicle is connected to the charging equipment in a public charging station.

When overvoltage occurs due to an abnormality in the equipment in the public charging station, the overvoltage can be transmitted to the electric vehicle and can damage electric devices in the vehicle.

An aspect of the present disclosure provides an isolation charging control apparatus of a vehicle that can prevent an in-vehicle device from being damaged by implementing a charging control apparatus of a vehicle in the isolated manner to prevent overvoltage from being transmitted to the in-vehicle device when the overvoltage is applied, and a system having the same.

According to an aspect of the present disclosure, an isolation charging control apparatus of a vehicle may include a first vehicle charging control apparatus receiving a control pilot signal for charging control from a charging station system and to receive power from the charging station system and a second vehicle charging control apparatus isolated from the first vehicle charging control apparatus and performing vehicle charging control, using a signal received from the first vehicle charging control apparatus.

In an embodiment, the first vehicle charging control apparatus may include a control pilot signal duty ratio sensor changing a state of the control pilot signal and to sense a duty ratio of the control pilot signal and a control pilot signal level detector detecting a voltage level of the control pilot signal.

In an embodiment, the control pilot signal duty ratio sensor may include a first isolation element operated by the control pilot signal and transmitting the duty ratio of the control pilot signal to the second vehicle charging control apparatus.

In an embodiment, the isolation element may include a photodiode operating as a light emitting device.

In an embodiment, the control pilot signal duty ratio sensor may further include a first state conversion device converting the voltage level of the control pilot signal, which is turned on when an inlet of the vehicle is connected to a charging connector, from a first level to a second level lower than the first level and a second state conversion device converting the voltage level of the control pilot signal from the second level to a third level lower than the second level, when a switch for starting charging is turned on.

In an embodiment, the second state conversion device may include a second isolation element receiving a turn-on signal from the second vehicle charging control apparatus and to be turned on, when the switch for starting charging is turned on.

In an embodiment, the control pilot signal duty ratio sensor may include a first resistance element and a second resistance element connected in series between a power supply terminal and a ground terminal and a comparator. The comparator is configured to receive the control pilot signal, the voltage level of which is converted by the second state conversion device, and a voltage of a common node of the first resistance element and the second resistance element, to compare the voltage level of the control pilot signal with the voltage of the common node, and to amplify the comparison result.

In an embodiment, a resistor value of each of the first resistance element and the second resistance element may be configured such that a voltage level of the common node of the first resistance element and the second resistance element, which is applied to the comparator, becomes a value less than a minimum value of the voltage level of the control pilot signal.

In an embodiment, the control pilot signal level detector may include a buffer receiving the control pilot signal applied from the charging station system and to buffer the control pilot signal, a peak detector detecting a peak current of the control pilot signal output from the buffer, a voltage controlled oscillator outputting a frequency signal in proportion to the peak current and an isolation element transmitting the frequency signal to the second vehicle charging control apparatus in an isolated manner.

In an embodiment, the apparatus may further include a proximity detection signal detector detecting a proximity detection signal capable of detecting whether a charging connector is plugged into a vehicle inlet.

In an embodiment, the proximity detection signal detector may be configured to distinguishably detect a state where the charging connector is not plugged into the vehicle inlet, a case where the charging connector is plugged into the vehicle inlet but a switch for charging in the charging connector is turned off, or a case where the charging connector is plugged into the vehicle inlet and the switch for charging in the charging connector is turned on, using a proximity detection signal applied from the charging connector.

In an embodiment, the proximity detection signal detector may include a first comparator driven by receiving a first voltage by the proximity detection signal, and a second voltage obtained by dividing a power supply voltage and a ground voltage by a resistance element, a first isolation element driven by an output of the first comparator and transmitting a signal to the second vehicle charging control apparatus, a second comparator driven by receiving the first voltage by the proximity detection signal, and a second voltage from dividing the power supply voltage and the ground voltage by the resistance element, and a second isolation element driven by an output of the second comparator and transmitting a signal to the second vehicle charging control apparatus.

In an embodiment, both the first isolation element and the second isolation element may be turned off, when the charging connector is not plugged into the vehicle inlet. The first isolation element may be turned on and the second isolation element may be turned off when the charging connector is plugged into the vehicle inlet but a switch for charging in the charging connector is turned off, and both the first isolation element and the second isolation element may be turned on when the charging connector is plugged into the vehicle inlet and the switch for charging in the charging connector is turned on.

In an embodiment, the second vehicle charging control apparatus may include an isolation receiver including at least one or more isolation elements receiving a duty ratio of the control pilot signal, a frequency signal of the control pilot signal, a proximity detection signal from an isolation element of the first vehicle charging control apparatus in an isolated state.

In an embodiment, the second vehicle charging control apparatus may further include an isolation converter supplying power to the first vehicle charging control apparatus in an isolated state.

In an embodiment, the second vehicle charging control apparatus may include a charging start device including an isolation element driven depending on an on/off state of a switch for starting charging and transmitting a charging start signal to the first vehicle charging control apparatus.

According to an aspect of the present disclosure, a system may include a charging connector to which a vehicle inlet is connected for charging, a first vehicle charging control apparatus receiving a control pilot signal for charging control from a charging station system and to receive power, and a second vehicle charging control apparatus isolated from the first vehicle charging control apparatus and performing vehicle charging control, using a signal received from the first vehicle charging control apparatus.

In an embodiment, the charging connector may include a first resistance element and a switch connected in series between a power supply terminal and a ground terminal, a second resistance element and a third resistance element connected in series between the first vehicle charging control apparatus and the ground terminal, and a diode provided between a common node of the first resistance element and the switch and a common node of the second resistance element and the third resistance element.

In an embodiment, the first vehicle charging control apparatus may include a control pilot signal duty ratio sensor converting a state of the control pilot signal and to sense a duty ratio of the control pilot signal, a control pilot signal level detector detecting a voltage level of the control pilot signal, and a proximity detection signal detector detecting a proximity detection signal capable of detecting whether the charging connector is plugged into the vehicle inlet.

In an embodiment, the second vehicle charging control apparatus may include a controller including at least one or more isolation elements receiving a duty ratio of the control pilot signal, a frequency signal of the control pilot signal, a proximity detection signal from an isolation element of the first vehicle charging control apparatus in an isolated state and an isolation converter supplying power to the first vehicle charging control apparatus in an isolated state.

The above and other aspects, features and advantages of the present disclosure will be more apparent from the following detailed description taken in conjunction with the accompanying drawings:

FIG. 1 is a view for describing an example of a vehicle charging device;

FIG. 2 is a block diagram illustrating a configuration of a vehicle system including a vehicle charging control apparatus, according to an embodiment of the present disclosure;

FIG. 3 is a detailed circuit diagram of a control pilot signal duty ratio sensor and a control pilot signal level detector of FIG. 2 ;

FIG. 4 is a timing diagram for describing a state change of a control pilot signal, according to an embodiment of the present disclosure;

FIG. 5 is a detailed circuit diagram of a proximity detection signal detector of FIG. 2 ;

FIG. 6 is a detailed circuit diagram of a controller of a second vehicle charging control apparatus of FIG. 2 ; and

FIG. 7 is a detailed circuit diagram of an isolation converter of FIG. 2 .

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals will be used throughout to designate the same or equivalent elements. In addition, a detailed description of well-known features or functions will be ruled out in order not to unnecessarily obscure the gist of the present disclosure.

In describing elements of embodiments of the present disclosure, the terms first, second, A, B, (a), (b), and the like may be used herein. These terms are only used to distinguish one element from another element, but do not limit the corresponding elements irrespective of the nature, order, or priority of the corresponding elements. Furthermore, unless otherwise defined, all terms including technical and scientific terms used herein are to be interpreted as is customary in the art to which this invention belongs. It will be understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of the present disclosure and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Referring to FIG. 1 , in an implementation of an electric vehicle, when overvoltage occurs due to an abnormality in the equipment in a public charging station, the overvoltage can be transmitted to an in-vehicle device through a power line, a CP line, and a PD line. For example, the overvoltage may be applied to not only a vehicle charging device 21 but also a Battery Management System (BMS) 23 , an Electric Power Control Unit (EPCU) 24 , an Integrated Gateway Power control Module (IGPM) 25 , an Audio Video Navigation (AVN) 26 , or the like, which is the in-vehicle device, and thus the devices of the vehicle may be damaged.

When a connector is plugged to charge the vehicle charging device 21 at the charging station with the overvoltage problem, not only the vehicle charging device 21 but also the other in-vehicle devices 23 , 24 , 25 , and 26 may be damaged and need to be replaced, thereby increasing the replacement cost.

The present disclosure discloses a configuration that inhibits overcurrent from being applied to the vehicle system by performing charging through isolation communication between a charging station system and a vehicle system even though overcurrent is applied from a charging station system in a state where a vehicle inlet is connected to a charging station system for charging, thereby minimizing the damage of the in-vehicle part.

Below, various embodiments of the present disclosure will be described in detail with reference to FIGS. 2 to 7 .

FIG. 2 is a block diagram illustrating a configuration of a vehicle system including a vehicle charging control apparatus, according to an embodiment of the present disclosure.

Referring to FIG. 2 , a system according to an embodiment of the present disclosure may perform charging by allowing a charging station system 100 to provide a vehicle system 200 with electrical energy while the charging station system 100 and the vehicle system 200 are connected through a charging connector 300 .

The charging station system 100 refers to a system performing charging by supplying electrical energy to a vehicle connected through the charging connector 300 ; the charging station system 100 may include a resistor R 101 and may supply the voltage of −12 V to 12 V.

The vehicle system 200 according to an embodiment of the present disclosure includes a first vehicle charging control apparatus 220 and a second vehicle charging control apparatus 230 . At this time, the vehicle system 200 may be mounted in an electric vehicle requiring charging.

The charging connector 300 is a configuration for connecting the vehicle system 200 to the charging station system 100 ; the charging is performed only when the charging connector 300 is correctly plugged into the vehicle inlet.

The charging connector 300 includes resistors R 102 , R 103 , and R 104 , a diode D 101 , and a switch S 3 . In embodiments, the resistor R 104 and the switch S 3 are connected in series; one end of the resistor R 104 is connected to a power supply terminal V+; the other end thereof is connected to one end of the switch S 3 ; the other end of the switch S 3 is connected to a ground terminal GND. In the meantime, the resistor R 102 and the resistor R 103 are connected in series; one end of the resistor R 102 is connected to a proximity detection signal detector 223 ; the other end of the resistor R 102 is connected to one end of the resistor R 103 ; the other end of the resistor R 103 is connected to the ground terminal GND. The diode D 101 is connected between the common node of the resistor R 104 and the switch S 3 and the common node of the resistor R 102 and the resistor R 103 ; the diode D 101 may be provided in a direction from the common node of the resistor R 102 and the resistor R 103 to the common node of the resistor R 104 and the switch S 3 .

The first vehicle charging control apparatus 220 and the second vehicle charging control apparatus 230 may control vehicle charging; the first vehicle charging control apparatus 220 and the second vehicle charging control apparatus 230 may perform communication for charging while being electrically isolated from each other.

The first vehicle charging control apparatus 220 includes a control pilot signal (CP) duty ratio sensor 221 , a control pilot signal (CP) level detector 222 , and the proximity detection signal (PD) detector 223 . In embodiments, the control pilot signal CP refers to a signal for exchanging information of a vehicle between the charging station system 100 and the vehicle system 200 . The proximity detection signal PD detects whether the connector of the charging station system 100 is correctly plugged into the inlet of a vehicle.

The control pilot signal (CP) duty ratio sensor 221 changes the state of the control pilot signal and provides the second vehicle charging control apparatus 230 with the duty of the pilot signal.

The control pilot signal (CP) level detector 222 detects the voltage level of the control pilot signal.

The control pilot signal CP may have the PWM format of 1 kHz; the control pilot signal CP may be transmitted from the charging station system 100 to the vehicle system 200 ; as illustrated in Table 1 below, the control pilot signal CP may be divided into five states depending on the states of the charging station system 100 and the vehicle system 200 and may be transmitted while the state of the control pilot signal is changed.

State A is the case that the charging station system 100 and the vehicle system 200 are not connected to each other; the charging station system 100 outputs a DC signal of 12 V and the vehicle system 200 receives “0” V because the vehicle is not connected to the charging station system 100 . When a connector is plugged into a vehicle inlet, the control pilot signal may be in state B, the charging station system 100 outputs a signal of 1 kHz (+9 V), and the vehicle system 200 detects the signal. When the vehicle system 200 is ready to be charged, the vehicle system 200 may change the state of the control pilot signal to state C by turning on the switch S 2 (illustrated in FIG. 6 below) and the vehicle system 200 receives a PWM signal of +6 V.

The proximity detection signal (PD) detector 223 may determine whether the connector is plugged into a vehicle inlet, through a proximity detection signal. In embodiments, the proximity detection signal detector 223 may detect items to be described below, through the proximity detection signal.

The second vehicle charging control apparatus 230 may be in a state where the second vehicle charging control apparatus 230 is isolated from the first vehicle charging control apparatus 220 ; the second vehicle charging control apparatus 230 may obtain control pilot signal duty information, control pilot signal voltage level information, and proximity detection signal information from the first vehicle charging control apparatus 220 . To this end, the second vehicle charging control apparatus 230 includes a power IC 231 , an isolation converter 232 , and a controller 233 .

The power IC 231 supplies a power supply voltage. The isolation converter 232 provides the first vehicle charging control apparatus 220 with the power supply voltage received from the power IC 231 . In embodiments, the isolation converter 232 may supply power in a state isolated from the first vehicle charging control apparatus 220 . For example, the isolation converter 232 includes an isolation transformer; the isolation transformer is a transformer in which the AC power receiving side (primary side) and the power supply side (secondary side) are electrically isolated from each other; the isolation transformer is used to exchange to the non-ground type transmission line and to reduce noise; the isolation transformer may prevent mutual interference between power sources through the isolation between the primary side and the secondary side, and may block the noise or impulsive abnormal voltage of the primary side.

The controller 233 may turn on and off the switch S 2 for starting charging and may obtain the control pilot signal duty information, the control pilot signal voltage level information, and the proximity detection signal information from the first vehicle charging control apparatus 220 .

As such, the charging station system 100 transmits a control pilot signal and a proximity detection signal to the first vehicle charging control apparatus 220 ; the first vehicle charging control apparatus 220 performs signal conversion and isolation processing to provide the second vehicle charging control apparatus 230 with the performed result. In embodiments, the ground terminal of the first vehicle charging control apparatus 220 is connected to the charging station system 100 ; the ground terminal of the second vehicle charging control apparatus 230 is connected to a vehicle chassis; the ground terminal of the first vehicle charging control apparatus 220 and the ground terminal of the second vehicle charging control apparatus 230 may be formed to be isolated. Furthermore, the second vehicle charging control apparatus 230 may supply the battery power of 12 V to the first vehicle charging control apparatus 220 through an isolated DC-DC converter such as a flyback converter.

The overvoltage is not transmitted to the entire parts inside the vehicle, but only to the first vehicle charging control apparatus 220 , when overvoltage is applied because a fault occurs in the charging station system 100 and the first vehicle charging control apparatus 220 ; the breakage of the second vehicle charging control apparatus 230 may be prevented or avoided even though the first vehicle charging control apparatus 220 is broken; as a result, it is possible to repair the fault by replacing only the first vehicle charging control apparatus 220 , thereby reducing the cost.

FIG. 3 is a detailed circuit diagram of the control pilot signal duty ratio sensor 221 and the control pilot signal level detector 222 of FIG. 2 .

Referring to FIG. 3 , the control pilot signal duty ratio sensor 221 includes a capacitor C 201 , a first state conversion device 2210 , a second state conversion device 2220 , resistors R 201 and R 202 , a comparator U 201 , a photodiode IS 01 _T, and a resistor R 203 .

The capacitor C 201 receives a control pilot signal CP applied by the charging station system 100 , and then is charged. In embodiments, the control pilot signal is output as a DC signal of 12 V (a first state, state A); the level of the control pilot signal is dropped by the resistor R 101 , and then the control pilot signal is applied to the capacitor C 201 .

The first state conversion device 2210 includes a zener diode DZ 201 ; when a vehicle inlet is connected to a connector, the zener diode DZ 201 is turned on and is connected to a ground terminal; the control pilot signal of 12 V is dropped and varies between 0 V and 9 V, and the state of the control pilot signal enters state B 1 (a second state).

The second state conversion device 2220 includes a phototransistor IS 02 _R and a zener diode DZ 202 . When a photodiode IS 02 _T of the second vehicle charging control apparatus 230 (see FIG. 6 ) is turned on to start charging, the phototransistor IS 02 _R is turned on, and the zener diode DZ 202 operates and is connected to the ground terminal, and the control pilot signal varies between 0 V and 6 V and enters state C (a third state). In embodiments, the photodiode IS 02 _T is a light emitting device and the phototransistor IS 02 _R is a light receiving device; when the light emits by electric energy and light energy is output by the photodiode IS 02 _T, the phototransistor IS 02 _R, which is electrically isolated from the photodiode IS 02 _T, receives the light energy and is turned on. In embodiments, each of the first vehicle charging control apparatus 220 and the second vehicle charging control apparatus 230 may include a pair of a photodiode being the light emitting device and a phototransistor being the light receiving device, which are electrically isolated, and may be able to transmit energy in the isolated state. As such, even though overvoltage is applied to the first vehicle charging control apparatus 220 , the overvoltage is not transmitted to the second vehicle charging control apparatus 230 because the second vehicle charging control apparatus 230 is isolated, thereby preventing the damage due to the overvoltage.

The resistors R 201 and R 202 are connected to each other in series between a power supply terminal and a ground terminal and then the voltage of the common node is applied to terminal (+) of the comparator U 201 .

As described in Equation 1, terminal (+) of the comparator U 201 may set the values of the resistors R 201 and R 202 so as to be less than the minimum value of the voltage level of the control pilot signal.

The comparator U 201 transmits the duty ratio of the control pilot signal to the phototransistor IS 02 _R of the second vehicle charging control apparatus 230 through the photodiode IS 01 _T regardless of the voltage level of the control pilot signal. At this time, the photodiode IS 01 _T is a light emitting device and the phototransistor IS 01 _R (see FIG. 6 ) is a light receiving device; when the light emits by electric energy and light energy is output in the photodiode IS 01 _T, the phototransistor IS 01 _R, which is electrically isolated from the photodiode IS 01 _T, receives the light energy and is turned on. The resistor R 203 is provided between the power supply terminal and the photodiode IS 0 _T.

The control pilot signal level detector 222 provides the second vehicle charging control apparatus 230 with the voltage level of the control pilot signal in an isolation state.

To this end, the control pilot signal level detector 222 includes a buffer U 301 , a resistor R 301 , a peak detector 2230 , a resistor R 302 , a Voltage Controlled Oscillator (VCO) U 302 , a current amplifier Q 301 , a resistor R 303 , and a photodiode IS 03 _T.

The buffer U 301 may buffer the control pilot signal such that the peak detector of the next stage operates stably.

The resistor R 301 is provided between the buffer U 301 and the diode D 301 . When a PWM pulse is applied in a state where the capacitor C 301 is fully discharged, the resistor R 301 may prevent or inhibit excessive charging current from flowing into the buffer U 301 .

The peak detector 2230 includes the diode D 301 and the capacitor C 301 for the purpose of detecting the peak value of the voltage applied from the output terminal of the resistor R 301 .

The diode D 301 stores the maximum voltage (peak voltage) of the voltage level output from the buffer U 301 and the resistor R 301 , in the capacitor C 301 . The diode D 301 may prevent the voltage stored in the capacitor C 301 from being discharging, when the PWM pulse from the buffer U 301 disappears.

The resistor R 302 is provided between node {circle around (b)} and the ground terminal. The resistor R 302 may form a path in which the current flows from the capacitor C 301 , when the level of the PWM pulse voltage is lowered; the value of the resistor R 302 may be set to a value great enough not to affect the detected peak voltage. The capacitor C 301 and the resistor R 302 may be set by the following Equation 2. The meaning of Equation 2 is to set ‘τ’ such that the voltage falls from V 0 to V(t) during time ‘t’. As the drop of the voltage falling from V 0 to V(t) is less, ripple may be less and the peak may be maintained well.

The VCO U 302 refers to a VCO; and the VCO U 302 outputs a frequency signal PWM in proportion to the peak voltage based on the peak voltage detected by the peak detector 2230 .

The current amplifier Q 301 amplifies the current output by the VCO U 302 , to drive the photodiode IS 03 _T.

The resistor R 303 is provided between the current amplifier Q 301 and the photodiode IS 03 _T. The photodiode IS 03 _T is a light emitting device; the photodiode IS 03 _T provides the phototransistor IS 03 _R of the second vehicle charging control apparatus 230 with the voltage CP_VMD of a PWM pulse of the pilot signal in the form of a frequency.

Hereinafter, a describing of a state change of a control pilot signal of an vehicle will be described with reference to Table 1 and FIG. 4 . Table 1 is a table indicating the state of a control pilot (CP) according to a state where a connector is plugged. FIG. 4 is a timing diagram for describing a state change of a control pilot signal, according to an embodiment of the present disclosure.

Referring to FIG. 4 , the second vehicle charging control apparatus 230 starts charging by turning on the switch S 2 , when a PWM signal is applied as the control pilot signal.

While the control pilot signal CP maintains the DC voltage of 12 V in a section (state A, the first state) where a connector is not plugged into an inlet, the control pilot signal CP maintains the DC voltage of 9 V in section B 1 (the second state) where the connector is plugged into a vehicle inlet and then maintains PWM of 9 V in section B 2 .

Afterward, when the charging preparation is completed, the first vehicle charging control apparatus 220 starts charging by operating the control pilot signal between 0 V and 6 V; when charging is completed, the phototransistor IS 02 _T is turned off and the level of the control pilot signal is between 0 V and 9 V.

Afterward, when the connector is removed from the vehicle inlet (state A), the control pilot signal is in +12 V/−12 V level.

FIG. 5 is a detailed circuit diagram of the proximity detection signal detector 223 of FIG. 2 .

Referring to FIG. 5 , as illustrated in Table 3, the proximity detection signal detector 223 may detect at least one state of charging connector disconnection, switch S 3 ON and connector connection, or switch S 3 off and connector connection, through a proximity detection signal.

The proximity detection signal detector 223 includes resistors R 401 and R 402 , a zener diode DZ 401 , resistors R 403 , R 404 , and R 405 , comparators U 401 - 1 and U 401 - 2 , photodiodes IS 04 _T and IS 05 _T, and resistors R 406 and R 407 . The resistor R 401 is connected to one end of the resistor R 102 of the vehicle connector 210 ; the resistor R 402 and the zener diode DZ 401 are connected to each other in series between a power supply terminal and a ground terminal and the common node {circle around (c)} thereof is connected to the output terminal of the resistor R 401 . At this time, the voltage of the common node {circle around (c)} is input to terminal (+) of the comparators U 401 - 1 and U 401 - 2 .

The resistors R 403 , R 404 , and R 405 are connected in series between the power supply terminal and the ground terminal; the voltage of the common node {circle around (d)} of the resistors R 403 and R 404 is input to input terminal (−) of the comparator U 401 - 1 . The voltage of the common node {circle around (e)} of the resistors R 404 and R 405 is input to input terminal (−) of the comparator U 401 - 2 .

The photodiodes ISO 4 _T and IS 05 _T are provided to output terminals of the comparators U 401 - 1 and U 401 - 2 , respectively; the resistor R 406 is provided between the power supply terminal and the photodiode ISO 4 _T; the resistor R 407 is provided between the power supply terminal and the photodiode IS 05 _T.

1) When a connector is not connected, the voltage at common node {circle around (c)} rises to the highest level; because the voltage at common node {circle around (c)} is higher than the voltage at node {circle around (d)} and {circle around (e)} and the comparators U 401 - 1 and U 401 - 2 are in a float state (High), both the photodiodes ISO 4 _T and IS 05 _T are turned off.

In the meantime, 2) when the vehicle connector is connected but the switch S 3 is in an off state, the voltage at node {circle around (c)} is set to be lower than the voltage at node {circle around (d)} and higher than the voltage at node {circle around (e)} due to the series connection of the resistors R 102 and R 103 . Accordingly, the output of the comparator U 401 - 1 in which (−) voltage is higher, is in a low level, and the photodiode ISO 4 _T is turned on; but the photodiode IS 05 _T still remains in an off state.

3) When the vehicle connector is connected and the switch S 3 is turned on, the voltage at node {circle around (c)} is generated by the resistor R 102 and the zener diode D 101 ; because the voltage at node {circle around (c)} is lower than the voltage at node {circle around (d)} and {circle around (e)}, the photodiodes ISO 4 _T and IS 05 _T are turned on.

FIG. 6 is a detailed circuit diagram of the controller 233 of the second vehicle charging control apparatus of FIG. 2 .

Referring to FIG. 6 , the controller 233 includes an isolation receiver 234 and a charging start device 235 .

The isolation receiver 234 includes phototransistors IS 01 _R, IS 03 _R, IS 04 _R, and IS 05 _R, which are light receiving devices, and a resistor device RA 501 .

The phototransistors IS 01 _R, IS 03 _R, IS 04 _R, and IS 05 _R that are light receiving devices may receive light energy by the photodiodes IS 01 _T, IS 03 _T, IS 04 _T, and IS 05 _T being the light emitting device included in the first vehicle charging control apparatus 220 and may convert the light energy to electrical energy. In embodiments, the phototransistor IS 01 _R may obtain a control pilot duty CP_DUTY; the phototransistor IS 03 _R may obtain a control pilot level CP_VMD; the phototransistors IS 04 _R and IS 05 _R may obtain state information of the proximity detection signal.

The charging start device 235 includes the photodiode IS 02 T and a resistor R 501 , which are connected in series between the power supply terminal and the switch S 2 . The photodiode IS 02 _T is turned on and then the phototransistor IS 02 _R included in the first vehicle charging control apparatus 220 is turned on, when the switch S 2 is turned on to start charging. As such, the level of the control pilot signal operates at 6 V.

FIG. 7 is a detailed circuit diagram of the isolation converter 232 of FIG. 2 .

The isolation converter 232 provides the first vehicle charging control apparatus 220 with the power supplied by the second vehicle charging control apparatus 230 in an isolation state. To this end, the isolation converter 232 may use a DC-DC converter such as a flyback converter.

Referring to FIG. 7 , a primary side 701 and a secondary side 702 are isolated through a transformer located in the middle; the primary side 701 to which Vi is applied may operates as the second vehicle charging control apparatus 230 supplying power, and the secondary side 702 to which Vo is applied may operates as the first vehicle charging control device 220 . An embodiment is shown in FIG. 7 as an isolation converter is implemented with a flyback converter.

However, an embodiment is not limited thereto. For example, the isolation converter may be implemented with a forward converter, a push-pull converter, an SEPIC converter, a half bridge converter, a full bridge converter, or the like.

Hereinabove, although the present disclosure has been described with reference to embodiments and the accompanying drawings, the present disclosure is not limited thereto, but may be variously modified and altered by those skilled in the art to which the present disclosure pertains without departing from the spirit and scope of the present disclosure claimed in the following claims.

Therefore, embodiments of the present disclosure are not intended to limit the technical spirit of the present disclosure, but provided only for the illustrative purpose. The scope of protection of the present disclosure should be construed by the attached claims, and all equivalents thereof should be construed as being included within the scope of the present disclosure.

The technology may prevent or inhibit an in-vehicle device from being damaged by preventing or inhibit overvoltage from being transmitted to the in-vehicle device when the overvoltage is applied, thereby minimizing unnecessary cost.

Besides, a variety of effects directly or indirectly understood through this disclosure may be provided.

Hereinabove, although the present disclosure has been described with reference to embodiments and the accompanying drawings, the present disclosure is not limited thereto, but may be variously modified and altered by those skilled in the art to which the present disclosure pertains without departing from the spirit and scope of the present disclosure claimed in the following claims.