KR20170073150A - Module for inrush current in electric vehicle supply equipment - Google Patents

Abstract

According to an aspect of the present invention, the inrush current reduction module includes a first connection portion configured to electrically connect or disconnect between a power supply portion in an electric vehicle charging device and an onboard battery charger in an electric vehicle, and a first connection portion electrically connected between the power supply portion and the first connection portion. And a second connection unit configured to electrically connect or disconnect between the power supply unit and the first connection unit, the current limiting unit configured to reduce an inrush current generated when the three-phase alternating current power is applied by the power supply unit, And a controller for controlling on / off of the first magnetic contactor of the first connection part and the second magnetic contactor of the second connection part. At this time, when the three-phase alternating current power is applied by the power supply unit, the controller changes the first magnetic contactor to the ON state to electrically conduct the first connection part, and after the first magnetic contactor is changed to the ON state, When the determined period has elapsed, the second magnetic contactors may be turned on to electrically connect the second connection portion.

Description

[0001] MODULE FOR INRUSH CURRENT IN ELECTRIC VEHICLE SUPPLY EQUIPMENT [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric vehicle charging field, and more particularly, to an electric vehicle charging device or facility that supplies three-phase AC power to an electric vehicle.

Due to recent carbon dioxide emission regulations, investment in environmentally friendly green cars is occurring in each country. Electric vehicles are vehicles representing these green car projects. In order to use such an electric vehicle, an electric vehicle charging device for charging the battery of the electric vehicle is required, and development thereof is actively being carried out.

FIG. 1 is an illustration of an electric vehicle (EV) including an electric vehicle charging equipment (EVSE) and an on-board charger for supplying a conventional three-phase AC power source to be. 1, the electric vehicle charging apparatus 100 includes a power supply unit 110 for supplying a three-phase AC power source (for example, 380 V AC), a distribution circuit breaker 120 for shutting off an overcurrent, And a first connection part 120 composed of a magnetic contactor for electrically selectively connecting the power supply part 110 and the onboard charging device 210 when the electric vehicle 100 and the electric vehicle 200 are connected to each other. The electric vehicle 200 further includes an onboard charger 210 for converting the three-phase AC power supplied from the electric vehicle charging apparatus 100 into direct current power and storing the converted direct current power, and an onboard charger 210 for charging And a battery 220 connected in series.

The onboard charger 210 of the electric vehicle 200 basically includes a capacitor bank composed of a plurality of capacitors for accumulating the converted DC power. Such a capacitor bank initially tries to momentarily introduce a significantly larger charge capacity to charge the empty charge, which causes the electric vehicle 200 to be charged by the supply voltage applied by the electric vehicle charging apparatus 100 An inrush current is generated which is much higher than the reference charging current.

Such inrush currents cause safety and maintenance problems in the electric vehicle charging process. Particularly, in the electric vehicle charging apparatus 200 for supplying the three-phase AC power to the electric vehicle 100, unnecessary operation of the circuit breaker in the charging device and unnecessary tripping of the electric leakage circuit breaker occur due to the inrush current.

Korea Patent Application No. 10-2014-0074569

Therefore, the present invention relates to an electric vehicle charging technology for limiting an electric current at the initial stage of charging in order to reduce an inrush current generated at the beginning of charging, To the charging device side).

According to an aspect of the present invention, an inrush current reduction module in an electric vehicle charging apparatus that supplies three-phase AC power to an electric vehicle including an onboard battery charger is configured to electrically connect the power supply unit in the electric vehicle charging apparatus and the onboard battery charger in the electric vehicle Wherein the first connection part comprises a first magnetic contactor for selectively conducting the first connection part, and a second connection part for connecting between the power supply part and the first connection part And a current limiting unit configured to reduce an inrush current generated when the three-phase alternating current power is applied by the power supply unit, wherein the current limiting unit includes a current limiting resistor that limits the current, And electrically connecting or disconnecting the power supply unit and the first connection unit, Wherein the second connection portion comprises a second connection portion connected in parallel with the current limiting resistor and selectively conducting the second connection portion, and the second connection portion, And a controller for controlling on / off of the first magnetic contactor of the connection part and the second magnetic contactor of the second connection part. At this time, when the three-phase alternating current power is applied by the power supply unit, the controller changes the first magnetic contactor to the ON state to electrically conduct the first connection part, and when the first magnetic contactor is in the ON state And changing the second magnetic contactors to an on state to electrically connect the second connection portion when a predetermined period of time has elapsed after the change.

As an embodiment, the resistance value of the current limiting resistor may be determined based on the allowable current of the first magnetic contactor and the supply voltage of the power supply.

In an embodiment, the allowable power of the current limiting resistor is determined based on a maximum value of the inrush current and a resistance value of the current limiting resistor, wherein a maximum value of the inrush current is proportional to a bank capacitance of the onboard charger, And is inversely proportional to the system inductance of the charger.

In an embodiment, the predetermined period of time for changing the second magnetic contactor to an on state may be characterized by being shorter than a period in which 90 percent of the charge is charged in the capacitor bank of the onboard charger.

The power supply unit may further include a distribution breaker disposed between the power supply unit and the current limiting unit and the second connection unit and configured to shut off the overcurrent.

According to the present invention, by limiting the current at the initial stage of charging to reduce the inrush current instantaneously generated at the beginning of charging, damage of the circuit in the charging device and tripping of the unnecessary circuit breaker can be prevented by the inrush current.

Further, according to the present specification, even if the inrush current reducing function is added to the electric vehicle charging apparatus side (charging apparatus side) instead of the electric vehicle side (load side) It is possible to provide charging with a current reduction function.

1 is a schematic configuration diagram of an electric vehicle charging apparatus and an electric vehicle according to the prior art.
2 is a schematic block diagram of an electric vehicle charging apparatus and an electric vehicle to which an inrush current reducing module according to an embodiment of the present invention is applied.
3 is a detailed block diagram of an inrush current reducing module of an electric vehicle charging apparatus according to an embodiment of the present invention.
4A is an example of a charging wave generated upon charging by an electric vehicle charging apparatus to which an inrush current reduction module according to an embodiment of the present invention is not applied, And is an example of a charging wave generated upon charging by an electric vehicle charging apparatus to which an inrush current reduction module is applied.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings and the accompanying drawings, but the scope of the claims is not limited or limited by the embodiments.

As used herein, terms used in the present specification are selected from the general terms that are currently widely used, while taking into consideration the functions, but these may vary depending on the intention or custom of the artisan or the emergence of new techniques. Also, in certain cases, there may be a term selected by the applicant at will, in which case the meaning will be described in the description part of the corresponding specification. Therefore, it is intended that the terminology used herein should be interpreted based on the meaning of the term rather than on the name of the term, and on the entire contents of the specification.

2 is a schematic block diagram of an electric vehicle charging apparatus and an electric vehicle to which an inrush current reducing module according to an embodiment of the present invention is applied.

In this specification, the electric vehicle charging apparatus 100 refers to a device for supplying the electric vehicle 200 with three-phase alternating current power applied with an inrush current reducing module including a plurality of magnetic contactors, Means an electric vehicle configured to convert a three-phase alternating-current power supplied from the automobile charging apparatus 100 into direct-current power, accumulate the converted direct-current power, and charge the battery 220 using the converted direct-current power. In this specification, a magnetic contactor (MC) is connected to each line corresponding to each phase (R, S, T phase) of the power supply unit 110, and uses a magnetic force of the built- As shown in FIG.

Referring to FIG. 2, the electric vehicle charging apparatus 100 includes a power supply unit 110, a distribution circuit breaker 120, a first connection unit 130, a second connection unit 140, a current restriction unit 150, 160 < / RTI > In this specification, the remaining components of the electric vehicle charging apparatus 100 except for the power supply unit 110, that is, the distribution circuit breaker 120, the first connection unit 130, the second connection unit 140, And the controller 160 may be abbreviated as an inrush current reducing module. According to an embodiment, the inrush current reduction module may be a module including only the first connection part 130, the second connection part 140, the current restriction part 150, and the controller 160. Further, according to the embodiment, the inrush current reducing module may further include a current supply device, a surge protector, and an earth leakage breaker.

As described above with reference to FIG. 1, the power supply unit 110 may supply a three-phase AC power source (for example, AC 220V or AC 380V), and the distribution circuit breaker 120 may be a circuit breaker , A Mold Case Current Breaker (MCCB), or a No Fuse Breaker (NFB).

The first connection unit 130 is configured to electrically connect or disconnect, that is, selectively connect, the power supply unit 110 in the electric vehicle charging apparatus 100 and the onboard charging apparatus 210 in the electric vehicle 200 . For example, when the charging apparatus 100 of the electric vehicle 200 and the electric vehicle 200 are connected through a connection means such as a charging cable (or charging starts), the first connection unit 130 is connected to the power supply unit 110 And the onboard charger 210 can be electrically connected to each other. Alternatively, when the charging apparatus 100 of the electric vehicle 200 and the electric vehicle 200 are disconnected (or the charging is terminated) through a connecting means such as a charging cable, The power supply unit 110 and the onboard charger 210 can be electrically disconnected from each other.

In one embodiment, the first connection 130 may include a first magnetic contactor that selectively conducts the first connection 130. The first magnetic contactor is changed from the off state to the on state according to the control signal of the controller 160 to electrically connect the first connection unit 130 or to turn off the first connection unit 130, May not be electrically conducted. When the first connection part 130 is electrically conducted, the three-phase alternating current power applied by the power supply part 110 may be provided to the onboard charger 210 of the electric vehicle 200.

The current limiting unit 150 is configured to electrically connect the power supply unit 110 and the first connection unit 130 and to reduce the inrush current generated when the three-phase alternating current power is applied by the power supply unit 110 . For example, when the first magnetic contactor of the first connection part 130 is changed from the off state to the on state and the second magnetic contactor of the second connection part 140 is in the off state, The first connection part 110 and the first connection part 130 can be electrically connected.

In one embodiment, the current limiter 150 may include a current limiting resistor that limits the current. These current limiting resistors are resistors connected to each line corresponding to each phase (R, S, T phase) of the power supply unit 110 to reduce an inrush current generated at the beginning of charging. In the illustrated embodiment, the first resistor is a resistor for limiting the current flowing on R, the second resistor is a resistor for limiting the current flowing on S, and the third resistor is a resistor for limiting the current flowing on T Resistance. At this time, each resistance may have the same resistance value. When the power supply unit 110 and the first connection unit 130 are electrically connected by the current limiting unit 150, the three-phase AC power supplied by the power supply unit 110 has a constant current limit May be provided to the onboard charger 210 of the electric vehicle 200.

The second connection unit 140 may be configured to electrically connect or disconnect the power supply unit 110 and the first connection unit 130. For example, when a predetermined period of time elapses after the first magnetic contactor of the first connection part 130 is changed from the off state to the on state, the second connection part 140 is electrically connected to the power supply part 110 and the first connection part 130 ) Can be electrically connected. Alternatively, the second connection unit 140 may electrically disconnect the power supply unit 110 from the first connection unit 130 when charging is terminated.

In one embodiment, the second connection portion 140 may include a second magneto contactor connected in parallel with the current limiting resistor and selectively conducting the second connection portion 140. The first magnetic contactor is changed from the off state to the on state according to the control signal of the controller 160 to electrically connect the first connection unit 130 or to turn off the first connection unit 130, May not be electrically conducted. When the second connection unit 140 is electrically connected, the three-phase AC power supplied by the power supply unit 110 may be supplied to the onboard charger 210 of the electric vehicle 200 without current limitation.

The controller 160 may control on / off of the first magnetic contactor of the first connection part 130 and the second magnetic contactor of the second connection part 140. The controller 160 may control the first magnetic contactor or the second magnetic contactor by transmitting a control signal to the first magnetic contactor or the second magnetic contactor.

In one embodiment, when the three-phase alternating current power is applied by the power supply unit 110, the controller 160 may turn on the first magnetic contactor to turn on the first connection unit 130 electrically. For example, when a control signal for starting charging from the electric vehicle 200 is received, the controller 160 may turn on the first magnetic contactor to turn on the first connection unit 130 electrically. Since the second connection unit 140 is in an electrically non-conductive state, the current due to the three-phase AC power applied by the power supply unit 110 flows through the current limiting resistors of the current limiting unit 150, 130 and flow to the onboard charger 210 of the electric vehicle 200 through the first connection part 130. Since the current flowing to the " first path " is subjected to the current limitation by the current limiting resistors in the current limiting unit 150, the charging apparatus 100 of the electric vehicle 200 reduces the inrush current generated at the beginning of charging .

In another embodiment, when a predetermined period of time has elapsed after the first magnetic contactor has been changed to the on state, the controller 160 may change the second magnetic contactor to the on state to electrically couple the second connection 140 have. For example, when about 100 ms elapses after the first magnetic contactor is turned on, the controller 160 may turn on the second magnetic contactor to turn on the second connection portion 140 electrically. The predetermined period for changing the second magnetic contactor to the ON state needs to be appropriately determined because it is related to the decrease of the inrush current and the heat damage of the current limiting resistor. In one embodiment, the predetermined period of time may be characterized by being shorter than the period during which 90 percent of the charge is charged in the capacitor bank of the onboard charger.

Since the second connection unit 140 is in an electrically conductive state, the current due to the three-phase AC power applied by the power supply unit 110 flows to the first connection unit 130 through the second connection unit 140, And can flow to the onboard charger 210 of the electric vehicle 200 through the first connection part 130. Since the electric current flowing to the " second path " is not subjected to the current limitation by the current limiting unit 150, the charging apparatus 100 of the electric vehicle 200 can control the three- Power supply can be provided.

Accordingly, the charging apparatus 100 of the electric vehicle 200 can prevent the damage caused by the inrush current by limiting the current at the initial stage of charging, and thereafter, the current is not limited, Phase AC power to the onboard charger 210 of the electric vehicle 200 at a sufficiently high level.

Referring to FIG. 2, the electric vehicle 200 may include an onboard charger 210 and a battery 220. The onboard charger 210 is electrically connected to the first connection part 130 of the charging device 100 of the electric vehicle 200 and is connected to the three phase AC power provided from the charging device 100 of the electric vehicle 200. [ A capacitor bank for storing the converted DC power, and a power supply output circuit for supplying the accumulated DC power to the battery 220. [0034] FIG. As an embodiment, the rectifier circuit may be composed of a bridge diode for converting an AC power source to a DC power source, and the capacitor bank may be composed of a plurality of capacitors. The bank capacitance of the capacitor bank of this onboard charger 210 and the system inductance of the onboard charger 210 can be used to determine the resistance value of the current limiting resistor, which will be described below.

In order for the charging apparatus 100 of the electric vehicle 200 to appropriately limit the current to reduce the inrush current, the resistance value of the current limiting resistor of the current limiting unit 150 and the value of the allowable electric power are appropriately determined in consideration of the system parameters of the charging system Should be determined. At this time, the resistance value of the current limiting resistor may be determined based on the allowable current of the first magnetic contactor and the supply voltage of the power supply unit 110. [ Because the current flows along the first path passing through the current limiting unit 150 and the first connection unit 130 at the beginning of charging, the allowable current of the first magnetic contactor of the first connection unit 130 determines the current limit value Because it plays an important role. When the allowable current of the first magnetic contactor is regarded as a limit value of the inrush current, the value of the current limiting resistor is a value obtained by dividing the supply voltage of the power supply unit 110 by the allowable current of the first magnetic contactor by Ohm's law. For example, when the supply voltage of the power supply 110 is 380 V and the allowable current of the first magnetic contactor is 40 A, the resistance value of the current-carrying resistor may be 380/40 = 9.5 (ohms). Accordingly, when the resistance of 10 (ohm) is selected as the current limiting resistor, the charging apparatus 100 of the electric vehicle 200 can reduce the inrush current to below the allowable current of the first magnetic contactor at the initial charging time.

)에 의해 돌입전류의 최대치와 전류제한 저항의 저항 값에 기초하여 결정될 수 있다. 이때, 돌입전류의 최대치는 아래의 방정식에 의해 결정될 수 있다.In addition, the value of the allowable power of the current limiting resistor is expressed by the power formula (

The maximum value of the inrush current and the resistance value of the current limiting resistor. At this time, the maximum value of the inrush current can be determined by the following equation.

(1)

(One)

Where C _B is the bank capacitance of the microfarads and LS is the system inductance of Micro Henry. At this time,

(2)

(2)

(3)

(3)

Substituting equation (3) into equation (1)

Lt; / RTI &

Because of,

finally,

.

Considering the above equation and the resistance value of the current limiting resistor,

.

Generally, since the allowable power is about twice the power consumption, about 50 W can be selected as the allowable power of the current limiting resistor.

3 is a detailed block diagram of an inrush current reducing module of an electric vehicle charging apparatus according to an embodiment of the present invention. 3, an example in which the power supply unit supplies the AC power in the three-phase four-wire system is explained as an example, but the same or similar explanation can be applied to the case where the power supply unit supplies the AC power in the three-phase three-wire system.

3, the inrush current reducing module may include a distribution circuit breaker 120, a first connection part 130, a second connection part 140, a current limiting part 150, and a controller . The description of the functions and operations of these configurations is already given in FIG. 2, and a detailed description thereof will be omitted. The inrush current reduction module may further include a voltage supply 170 such as a switched mode power supply (SMPS), a surge protector 180, and an earth leakage breaker 190 such as an electric leakage circuit breaker (ELCB).

Here, the SMPS is electrically connected to a single phase (for example, R phase) and a neutral line (N line) of the three-phase AC power source applied by the voltage supply unit, and is switch control for converting AC power to DC power Type power supply. The converted DC power can be transmitted to the controller. When the SMPS is used as the power supply unit as described above, output noise due to high-frequency switching and generation of electromagnetic waves are generated in many cases, and therefore, it is possible to further include a noise filter as shown in the figure. Further, it may further include a separate circuit breaker. 3, the SMPS is described as an example of the voltage supply device 170. However, it is apparent to those skilled in the art that other similar types of voltage supply devices 170 may be used for the inrush current reducing module.

Here, the surge protector 180 (SPD) is a protection unit that is electrically connected to each phase of the three-phase AC power source to suppress a surge voltage. For example, a voltage switching type SPD and a voltage suppression type SPD Lt; / RTI > Voltage switching type SPD is composed of discharge tubes, gas tubes and air gap elements. When the discharge start voltage is below the discharge start voltage, the discharge state is open. When the discharge start voltage is exceeded, the discharge is short circuited. It lasts for up to about 2 cycles and automatically returns to open when the surge is removed. In addition, the voltage suppression type SPD is used for MOV (Metal Oxide Varistor) and semiconductor diode which have nonlinear voltage / current characteristics, has a very low impedance against the voltage exceeding the operating voltage, In the following, it has a very high impedance and operates so that the voltage is suppressed by the correlation between line impedance and SPD impedance.

Here, the ELCB means a circuit breaker for preventing an overload as well as an overload. The earth leakage breaker 190 may be positioned at a rear end of the first connection part 130. 3, an ELCB is taken as an example of the earth leakage breaker 190. However, it is obvious to a person skilled in the art that the earth leakage breaker 190 such as a residual current protective device (RCD) may be used in the inrush current reducing module .

4A is an example of a charging wave generated upon charging by an electric vehicle charging apparatus to which an inrush current reduction module according to an embodiment of the present invention is not applied, And is an example of a charging wave generated upon charging by an electric vehicle charging apparatus to which an inrush current reduction module is applied.

4A is a wave measured under the evaluation conditions shown in the following table.

System Detail EV RenaultSamsung SM3 ZE GEN2 for AC charging IEC-61851-1 Charging EVSE Korea ULVAC 22 kW 3 phase chager MCCB and RCD Schneider electric 40 A, B type HPI MC (magnetic contactor) LSIS 40A MC

4A and 4B, the yellow wave indicates a control pilot (CP) signal, which is a control signal having a DC 12 V, 1 KHz waveform, a blue wave indicates an AC current delivered to the electric vehicle 200, and a red wave indicates an electric vehicle charging apparatus 100 ). ≪ / RTI >

4A, when the CP signal (for example, a signal of a voltage drop type at a certain level) for controlling the start of charging is input to the electric vehicle charging apparatus 100, the electric vehicle charging apparatus 100 AC power is supplied to start charging. At this time, it can be confirmed that an inrush current of about 103 A is instantaneously generated. This is an inrush current exceeding the charge reference value current of 40 A, and this inrush current may trip the progressive breaker or damage the circuit.

Referring to the dotted line in FIG. 4B, when a CP signal (for example, a signal of a voltage drop type at a certain level) for controlling the charging to start charging is input to the electric vehicle charging apparatus 100, ) Starts charging by supplying AC power. At this time, it can be confirmed that an inrush current of about 25 A or about 23 A is instantaneously generated. This is an inrush current which does not exceed the charging reference value current of 40 A. This reduced inrush current can prevent unnecessary tripping of the progressive breaker or damage to the circuit.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It should be understood that various modifications may be made by those skilled in the art without departing from the spirit and scope of the present invention.

100: electric vehicle charging device 200: Electric vehicle

Claims (5)

An inrush current reduction module in an electric vehicle charging apparatus that supplies three-phase alternating current power to an electric vehicle including an onboard charger,
A first connection unit configured to electrically connect or disconnect between a power supply unit in the electric vehicle charging apparatus and the onboard charger in the electric vehicle, the first connection unit including a first magnetic contactor for selectively conducting the first connection unit The first connection part;
A current limiting unit configured to electrically connect the power supply unit and the first connection unit and reduce a rush current generated when the three-phase alternating current power is applied by the power supply unit, the current limiting unit limits the current The current limiting portion including a current limiting resistor;
A second connection unit configured to electrically connect or disconnect between the power supply unit and the first connection unit, the second connection unit being connected in parallel with the current limiting resistor, and a second magnet The second connection portion including a Teck contactor; And
And a controller for controlling on / off of a first magnetic contactor of the first connection part and a second magnetic contactor of the second connection part,
The controller includes:
Wherein when the three-phase AC power is applied by the power supply unit, the first magnetic contactor is turned on to electrically connect the first connection unit,
Wherein when the predetermined period of time elapses after the first magnetic contactor is changed to the on state, the second magnetic contactors are turned on to electrically connect the second connection portion. The method according to claim 1,
The resistance value of the current-
Wherein the inrush current reduction module is determined based on the allowable current of the first magnetic contactor and the supply voltage of the power supply. 3. The method of claim 2,
The allowable power of the current-
Characterized in that the inrush current is determined based on a maximum value of the inrush current and a resistance value of the current limiting resistor, the maximum value of the inrush current being proportional to the bank capacitance of the onboard charger and inversely proportional to the system inductance of the onboard charger Current reduction module. The method according to claim 1,
Wherein the predetermined period of time to change the second magnetic contactor to an on state is shorter than a period in which the capacitor bank of the onboard charger is charged with 90 percent of the charge. The method according to claim 1,
Further comprising a distribution breaker located between the power supply, the current limiter and the second connection and configured to shut off the overcurrent.

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