WO2019225794A1

WO2019225794A1 - Non-contact power receiving device having electric vehicle overvoltage prevention function, charging system, and control method thereof

Info

Publication number: WO2019225794A1
Application number: PCT/KR2018/006362
Authority: WO
Inventors: 유효열; 조정구; 문용기; 한정호; 유주승; 김민호
Original assignee: (주)그린파워
Priority date: 2018-05-24
Filing date: 2018-06-04
Publication date: 2019-11-28
Also published as: KR101946027B1

Abstract

The present invention addresses a problem related to moving bodies, such as pure electric vehicles, plug-in hybrids, electric bicycles, and the like, which are driven using electric energy charged through non-contact charging, wherein when a battery is separated from a system due to charging stoppage, system failure, or the like, an overvoltage is caused in a high voltage system, resulting in the failure or reduced service life of a high voltage component. In order to solve this problem, the present invention provides a non-contact power receiving device having an electric vehicle overvoltage prevention function, a charging system, and a control method thereof, wherein: an overvoltage prevention means is employed in a power receiving device and prevents energy from being supplied to a high voltage system while ensuring a closed loop path for a power receiving current in order to prevent switching overvoltage that occurs when the power receiving current is cut off; and the overvoltage prevention means can discharge the high voltage system to ensure system safety without the addition of a separate discharge system, or can improve system safety, charging efficiency, and energy efficiency by converting the energy to be used for a different purpose.

Description

Non-contact receiving device, charging system having electric vehicle overvoltage protection function and control method thereof

The present invention relates to an overvoltage preventing means having an electric vehicle overvoltage protection function, a non-contact power receiving device and a non-contact power feeding device, and a control method thereof, and more particularly, to prevent a failure of a high-voltage system in a vehicle due to an overvoltage that may be induced when charging stops. The present invention relates to an overvoltage preventing means, a non-contact power receiving device, a non-contact power supply device, and a control method thereof.

As air pollution and environmental issues have become a major issue in the world recently, interest in electric vehicles is increasing instead of internal combustion engine cars using fossil fuels, and a lot of research and development is underway to commercialize these eco-friendly vehicles. have. Electric vehicles are limited in size and capacity of batteries and must be repeatedly charged and discharged. In the case of using a connector by wire for an electric vehicle, there are various inconveniences in the user's manual charging and in the charging process and the process of connecting the connector. To solve this problem, technologies for charging an electric vehicle wirelessly are being developed. Systems for wireless charging of automotive batteries generally consist of a power supply with a primary inductive circuit on the ground and a power receiver with a secondary inductive circuit mounted on the vehicle. Energy transfer between the power feeding device and the power receiving device is caused by electromagnetic induction. Compared to wired charging systems, wireless charging systems allow for improved user comfort and ergonomics due to the fact that there is no risk of losing a connection or no restrictions on the weight of the plug.

Meanwhile, in the electric vehicle having a non-contact charging system, as shown in FIG. 1, a high voltage system such as the non-contact power receiver 200, an inverter, a converter, etc. is commonly connected to the other side of the battery main relay connected to one side of the battery (hereinafter, "DC"). Link "). The non-contact power receiver 200, an inverter, a converter, and the like have a smoothing capacitor at the DC link connection. Here, the high voltage component connected to the DC link may be various components such as an electric water pump and a PTC heater in addition to an inverter and a converter. In the event of an unexpected abnormality such as a system stop, charge stop, breakdown of critical high voltage components, a crash, etc., for the safety of the system and the user, the in-vehicle controller turns off the battery main relay to disconnect the battery from the system. . Throughout the specification, the electric vehicle means not only a pure electric vehicle, but also a mobile vehicle that travels using charging energy such as a plug-in hybrid, a rechargeable fuel cell vehicle, and an electric bicycle.

The wireless charging system may be configured with an LC-LC method using an inductor and a capacitor as shown in FIG. 2A, or an LCCL-LCCL method using a plurality of inductors and capacitors as shown in FIG. 2B.

The power supply device of the LC-LC method or LCCL-LCCL method circuit and the input filter circuit of the current collector can be equivalently modeled as a sine wave current source as shown in FIG. 3A. In addition, the power receiving device 230 is connected to the battery 301 mounted on the electric vehicle to charge the battery 301, the battery main relay (between the power receiving device and other electric devices (not shown in the figure) and the battery ( 302 serves to block the battery charging or discharging path. The control of the battery main relay 302 may be performed by a controller (for example, a battery management system (BMS), not shown) provided in the electric vehicle. As described above, not only the problem of the battery itself, but also other Battery main relays can be turned off without notice for a variety of reasons, including abnormal conditions such as system failure or shock during charging.

When the battery main relay 302 is turned off during wireless charging, since the input filter circuit functions as a current source, the current charging the battery 301 continuously drives the smoothing capacitor 234 located in front of the battery main relay 302. By charging, the voltage of the capacitor is increased to generate an overvoltage, which not only causes the smoothing capacitor burnout, shorten the life of the power receiver, damage or deteriorate, but also shorten or shorten the life of components of the electrical device connected to the same node. In a point that may cause the power supply to the power supply device must be stopped through the wired or wireless communication between the electric vehicle controller such as BMS and the power supply device outside the vehicle before turning off the battery main relay 302.

However, there may be a time delay in communication between the power supply device outside the vehicle and the in-vehicle controller, and the delay of information transmission according to the time delay may cause the power supply device to supply power during the delayed time, which is connected to the power receiver and the connected device. It can damage the electrical equipment.

Furthermore, even when the in-vehicle controller does not turn off the battery main relay, when the electrical connection between the power receiver and the battery 310 is cut off for various reasons such as damage to the battery main relay 302 itself or disconnection of the battery 301 connecting cable. May occur. In this case, the in-vehicle controller cannot transmit the battery main relay off information to the feeder in advance, which can cause a relatively larger overvoltage, which can damage the power receiving device and the connected electrical device.

Although the current of the power supply for the ground power supply increases as the output voltage (smooth capacitor voltage) of the power receiving device increases, the change in the current is not so large that the power supply determines whether the battery main relay is turned off. There was a problem that it was very difficult to detect based on the amount of current.

In the prior art, the document US 2013-0162203A discloses a method for closing switches connected to a battery only when power from an external supply by induction is detected.

According to the present invention, in charging an in-vehicle battery by a non-contact power supply of an electric vehicle, when the battery main relay is turned off (opened), it is possible to quickly prohibit the power received from the power supply from charging the smoothing capacitor connected to the DC link. At the same time, a non-contact power receiving device for electric vehicles, a power supply device, and a control method thereof, including an overvoltage prevention means capable of preventing overvoltage generated when the current received from a power supply device having a current source characteristic is temporarily blocked to improve system safety. to provide.

According to the present invention, the non-contact power receiving device is provided in the interior of the electric vehicle, the power receiving unit for receiving power from the non-contact power supply device, the filter unit connected to the output of the power receiving unit, the rectifying unit connected to the output of the filter unit, the overvoltage protection connected to the output of the rectifying unit Means, an overvoltage protection means and a smoothing capacitor connected to a DC link (N0) to which the battery main relay is connected, wherein the overvoltage prevention means blocks the smoothing capacitor charge current and the discharge current based on the voltage of the smoothing capacitor to overvoltage the smoothing capacitor. Can be prevented from occurring and the circuit can be configured so that the current received from the non-contact power supply device can flow through a closed loop path different from the smoothing capacitor charging path so that the rate of change of the received current is equal to or less than a predetermined value.

The overvoltage protection means can provide a shorted path at the front or rear of the rectifier to prevent the rectified current from charging the smoothing capacitor.

The overvoltage preventing means determines whether the overvoltage protection condition is applicable based on the series diode provided between the rectifier and the smoothing capacitor, the protection switch provided in parallel between the rectifier and the series diode, and the voltage of the smoothing capacitor, and based on the determination result. Control means for controlling the protection switch.

With this configuration, even when the battery main relay is turned off, not only the overvoltage is induced in the smoothing capacitor by the received electric power, but also the effect of preventing the overvoltage from occurring by abruptly interrupting the received current. There is.

In the case of the series diode, when the output N1 of the rectifier part is connected to the anode side of the series diode, and the anode of the smoothing capacitor is connected to the cathode side of the series diode, the protection switch is turned on (closed). In addition, the node N1, which is an output of the rectifier, and the smoothing capacitor anode N0 may be electrically disconnected to prevent current from flowing between the rectifier, the protection switch, and the smoothing capacitor.

By such a configuration, when the protection switch is turned on, a reverse voltage is applied to the series diode so that the current of the smoothing capacitor may not flow through the protection switch, which may be a large capacity of the smoothing capacitor, and further, an inverter and a converter. Due to the characteristics of the electric vehicle that the smoothing capacitors of which can be connected in parallel, there is an effect of preventing excessive current from flowing to the protection switch, and shortening the life of the capacitor.

The overvoltage prevention means determines whether an overvoltage protection condition is applicable based on a gate switch provided between the rectifier and the smoothing capacitor, a protection switch provided in parallel between the rectifier and the gate switch, and a voltage at both ends of the smoothing capacitor, and based on the determination result. Control means for controlling the gate switch and the protection switch.

The gate switch may be one of a relay or a MOSFET, and the protection switch may be one of a thyristor, a MOSFET, an IGBT, or a SiCMOSFET.

According to this configuration, the current flows through a switch such as a MOSFET having a relatively low on-resistance (drain-source resistance) instead of a diode (the series diode) during normal battery charging when the battery main relay is on. On the other hand, the use of a MOSFET has a small voltage drop, so that the loss can be reduced and the efficiency can be improved.

The control means inputs the voltage across the smoothing capacitor, and outputs the voltage signal corresponding to the voltage across the smoothing capacitor. The input and output are electrically insulated voltage meter and the output of the isolated voltage meter and A voltage comparator comparing the reference voltage, a switch driver controlling on or off of the protection switch and the gate switch based on the output of the voltage comparator, and a signal inverter between the output of the voltage comparator and the switch driver for the gate switch may be provided. .

With this configuration, by implementing the control means in a relatively inexpensive and simple circuit without using a separate process, or a complicated procedure such as communicating with the vehicle controller or the host controller, it is economical and fast operation Guaranteed, reliable effect is excellent.

In addition, unlike the above configuration, if the signal inverter is located between the driver for the protective switch and the comparator, during the time delay by the signal inverter, the current flow path by the current source is temporarily interrupted, so that a significant overvoltage at the switch stage is obtained. Since the deterioration of the components such as the switch may reduce the life of the components such as the switch and cause burnout, there is an effect that the signal inverter is provided between the driver for the protective switch and the comparator and the comparator, not the comparator.

In addition, the control means inputs the voltage across the smoothing capacitor, and outputs a voltage signal corresponding to the voltage across the smoothing capacitor. The input and output are electrically insulated voltage meter and the output of the isolated voltage meter. A switch driver for controlling the on or off of the protection switch and the gate switch based on the respective outputs of the first and second voltage comparators and the first and second voltage comparators for comparing the predetermined reference voltages.

In addition, the protection switch and the gate switch may use the same switch.

According to this configuration, since the time difference between turning on or off the protection switch and the gate switch is minimized, switching overvoltage due to the switching time difference between the two switches can be prevented.

According to the present invention, a non-contact power receiving device including an over-voltage protection means for an electric vehicle is provided in the interior of the electric vehicle, the power receiving unit for receiving power from the non-contact power supply, the filter unit connected to the output of the power receiving unit, the rectifying unit connected to the output of the filter unit And a smoothing capacitor connected to the DC link N0 to which the output of the rectifier and the battery main relay are connected, and an overvoltage preventing means connected to one end of the output of the filter part and connected to a negative electrode and the other side of the smoothing capacitor. Blocking the smooth capacitor charge current and discharge current based on the voltage of the capacitor prevents overvoltage from occurring in the smooth capacitor, and configures a closed loop path through which the current received from the non-contact power supply device can flow. It can be made below a predetermined value.

The overvoltage protection means includes: first and second protection diodes having an anode connected to an input node N2 of the rectifier, one side of which is commonly connected to the cathodes of the first and second protection diodes, and the other side of which is connected to ground (G). The control unit 434 may determine whether the overvoltage protection condition is applicable based on the voltage of the switch and the smoothing capacitor, and control the protection switch based on the determination result.

According to such a configuration, the current flows directly through the lead wires without passing through a switch such as a diode (the series diode) or a MOSFET during normal battery charging when the battery main relay is turned on, thereby improving charging efficiency. In addition, since the overvoltage protection means can be additionally installed in the non-contact power receiving device that does not have the overvoltage protection function in use, there is an economic effect.

The control means inputs the voltage of both ends of the smoothing capacitor and outputs the voltage signal corresponding to the voltage of both ends of the smoothing capacitor. The input and output are electrically insulated voltage meter and the output of the isolated voltage meter and predetermined A voltage comparator for comparing the reference voltage, and a switch driver for controlling the on or off of the protection switch based on the output of the voltage comparator.

It may be determined whether the overvoltage protection condition corresponds to the overvoltage protection condition when the rate of change of the voltage across the smoothing capacitor exceeds a predetermined value.

In addition, a predetermined value compared with the rate of change of the voltage between the both ends may be set based on the capacitance value of the smoothing capacitor.

In addition, the predetermined value compared with the rate of change of the voltage between the both ends may be set based on the capacitance value of the smoothing capacitor and the capacitance value of the capacitor of the electric device commonly connected to the DC link.

According to such a configuration, it is possible to quickly determine whether the overvoltage protection function is operating, and to prevent a problem such as heat generation and a decrease in life due to the continuous flow of current through the protection switch.

According to the present invention, a non-contact charging system having an overvoltage protection function for an electric vehicle including the non-contact power receiving device and the non-contact power supply as described above, wherein the non-contact power supply is a measuring unit for measuring the amount of power or current supplied by the non-contact power supply during charging. A determination unit for determining that the overvoltage protection function of the non-contact power receiving device has been performed when the state of the measured power amount or current amount smaller than the predetermined value lasts for a predetermined time; It may include a control unit for controlling the power feeding device.

According to the present invention, when charging an in-vehicle battery by a non-contact power supply of an electric vehicle, when the battery connection path is interrupted, the current source at the same time quickly inhibits charging of the smoothing capacitor connected to the DC link by the power received from the power supply. It can cut off the current received from the power feeding device at a time to prevent overvoltage from occurring, thereby improving safety, improving efficiency during charging, and using simple circuit elements for controlling economic advantages and high reliability. In addition, there is an effect such as fast control operation, no need to communicate with the host controller or the vehicle controller, and there is an economic effect that the overvoltage protection means can be installed in a power receiving device that does not have an existing overvoltage protection function.

The features, advantages and technical and industrial significance of exemplary embodiments of the invention will be described below with reference to the accompanying drawings, wherein like reference numerals designate like elements.

1 is a diagram illustrating an electric vehicle including a non-contact power supply device, a current collector, an inverter, a motor, a converter, and the like.

2A and 2B are diagrams showing an example of a circuit configuration of a conventional non-contact power feeding device and power receiving device. 2A and 2B show a configuration of an LC-LC and LCCL-LCCL non-contact charging circuit, respectively.

3A and 3B are diagrams showing an equivalent circuit configuration of the conventional non-contact power feeding device and power receiving device shown in FIGS. 2A and 2B, and an example of a battery charging current and a smoothing capacitor voltage when the battery main relay is turned off.

4 is a diagram showing an example of a circuit configuration of an overvoltage protection means for a non-contact power receiving device according to Embodiment 1 of the present invention.

5A to 5E are diagrams showing an example of a circuit configuration of the overvoltage protection means for a non-contact power receiving device according to the second embodiment of the present invention.

6A to 6C are diagrams showing an example of a circuit configuration of the overvoltage protection means for a non-contact power receiving device according to Embodiment 3 of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail, referring drawings. Hereinafter, although some embodiment is described, combining suitably the structure demonstrated by each embodiment is anticipated from the beginning of an application. In addition, the same part is attached | subjected to the same or equivalent part in drawing, and the description is not repeated.

1 illustrates an electric vehicle including a non-contact power supply device and a current collector and an inverter, a motor, a converter, and the like.

Throughout the specification, not only pure electric vehicles, but also electric vehicles, collectively refer to mobile vehicles that run using charging energy such as plug-in hybrids, rechargeable fuel cell vehicles, and electric bicycles.

2A and 2B illustrate a charging system including a non-contact power supply device and a current collector for a conventional electric vehicle. 2A and 2B show non-contact power supply devices 101 and 102 and

current collectors

210 and 220 for an LC-LC method and an LCCL-LCCL method electric vehicle, respectively, which are conventionally used.

3A illustrates an equivalent circuit of the non-contact power supply devices 101 and 102 and the

current collectors

210 and 220 for the LC-LC method or the LCCL-LCCL method electric vehicle. Here, the power receiving portion and the filter portion of the non-contact power feeding device and the non-contact power receiving device can be equivalently viewed as a current source, which is shown as a sine wave current source 103. 3B shows the battery charge current (upper figure) and the voltage of the smoothing capacitor 234 (lower figure). When the battery main relay is turned off (opened), the battery charging current becomes zero, and the voltage of the smoothing capacitor 234 is increased, indicating a conventional problem that overvoltage is induced.

Embodiment 1

As shown in FIG. 4, the non-contact power receiver 230 is provided inside the electric vehicle, and includes a power receiver 231 for receiving electric power from the non-contact power feeder, and a filter unit 232 connected to the output of the power receiver 231. The rectifier 233 connected to the output of the filter unit 232, the overvoltage preventing unit 410 connected to the output of the rectifying unit 233, the DC link N0 to which the overvoltage preventing unit 410 is connected to the battery main relay 302. And a smoothing capacitor 234 connected to it.

Here, the filter unit 232 may be a resonant network.

Here, the power receiver 231 receives the power delivered in the form of a magnetic field, the rectifier 233 may be configured as a bridge circuit using a diode, and the smoothing capacitor functions to smooth the output voltage of the rectifier 233. .

In addition, one side of the battery main relay 302 is connected to the battery 301, the other side is connected to the DC link (N0), the DC link is an electrical device (for example, an inverter using the charging energy of the battery 301) , Converter, etc., not shown in the drawing), a power receiving device (charger) may be commonly connected.

In the present embodiment, the overvoltage preventing means 410 blocks the smoothing capacitor 234 charging current and the discharging current based on the voltage of the smoothing capacitor 234 to prevent the overvoltage from occurring in the smoothing capacitor 234, A closed loop path through which the electric current received from the non-contact power supply devices 101 and 102 can flow can be configured so that the rate of change of the electric current received is less than or equal to a predetermined value.

Preferably, the overvoltage preventing means 410 may include a series diode 411 provided between the rectifier 233 and the smoothing capacitor 234, and a protection switch provided in parallel between the rectifier 233 and the series diode 411. 412, and a control means for determining whether the overvoltage protection condition is applicable based on the voltage of the smoothing capacitor 234, and controlling the protection switch 412 based on the determination result.

Preferably, the control means inputs the voltage across the smoothing capacitor 234 and outputs a voltage signal corresponding to the voltage across the smoothing capacitor 234, but the input and output are electrically insulated voltage measuring devices. A voltage comparator comparing the output of the isolated voltage meter with a predetermined reference voltage, and a switch driver controlling on or off of the protection switch based on the output of the voltage comparator.

Preferably, whether or not the overvoltage protection condition corresponds to the overvoltage protection condition may be determined when the rate of change of the voltage across the smoothing capacitor 234 exceeds a predetermined value.

In addition, a discharge resistor system for discharging a DC link capacitor of an electric device (eg, an inverter or a converter) commonly connected to the DC link may be provided (not shown). The control means of the overvoltage preventing means directly transmits a driving signal to the discharge resistance system to operate the discharge resistance system, or transmits a forced discharge signal to a controller of the electric device so that the controller of the electric device controls the discharge resistance system. I can drive it. The discharge resistor system can lower the voltage of the DC link by discharging the smoothing capacitor. According to this configuration, even in a charging vehicle in which an inverter or the like is not activated, even when the battery main relay is turned off, energy charged in a capacitor connected to the DC link can be quickly discharged, thereby improving user electrical safety and system protection performance. There is an effect that can be improved.

In addition, the control means of the overvoltage protection means (Wake-up) to switch the controller of the electrical device (inverter, etc.) commonly connected to the DC link from the sleep mode to the active mode when the battery main relay is turned off Function). The overvoltage prevention means may instruct a forced discharge of the controller of the activated electric device (inverter, etc.).

In addition, the controller of the inverter activated by the overvoltage preventing means may discharge the capacitor connected to the DC link by applying a current to the motor using an inverter commonly connected to the DC link. Here, the current applied by the inverter may be characterized in that the current is controlled so as not to rotate the motor.

In addition, the controller of the converter activated by the control means of the overvoltage protection means can discharge the capacitor connected to the DC link by charging or supplying power to the auxiliary battery or the electric load connected to the auxiliary battery using a converter commonly connected to the DC link. have. Here, when the auxiliary battery is in a fully charged state, the electric load may be forcibly turned on (operation). In addition, the electric load may be limited to the electric load that is not recognized by the user as the five senses. For example, the electric load may be a coolant water pump, a radiator fan, a battery cooling fan, a PTC heater, an electric oil pump, or the like.

In addition, the overvoltage preventing means may simultaneously perform at least one or more of the overvoltage preventing methods described above.

Preferably, the series diode 411 is connected to the output N1 of the rectifier 233 and the anode side of the series diode 411, and has an anode of the smoothing capacitor 234 and a series diode 411. When the cathode side is connected and the protection switch 412 is turned on (closed), the node N1, which is an output of the rectifier 233, and the anode N0 of the smoothing capacitor 234 are electrically separated from each other. A current may not flow between the rectifier 233 and the protection switch 412 and the smoothing capacitor 234.

Embodiment 2

As shown in FIG. 5A, the non-contact power receiver 230 is provided inside the electric vehicle, and includes a power receiver 231 for receiving electric power from the non-contact power feeder, and a filter unit 232 connected to the output of the power receiver 231. The rectifier 233 connected to the output of the filter unit 232, the overvoltage preventing unit 420 connected to the output of the rectifying unit 233, the DC link N0 to which the overvoltage preventing unit 420 is connected to the battery main relay 302. And a smoothing capacitor 234 connected to it.

In the present embodiment, the overvoltage preventing means 420 blocks the smoothing capacitor 234 charging current and the discharging current based on the voltage of the smoothing capacitor 234 to prevent the overvoltage from occurring in the smoothing capacitor 234, A closed loop path through which the electric current received from the non-contact power supply devices 101 and 102 can flow can be configured so that the rate of change of the electric current received is less than or equal to a predetermined value.

Preferably, the overvoltage protection means 420 may include a gate switch 421 provided between the rectifier 233 and the smoothing capacitor 234, and a protection switch provided in parallel between the rectifier 233 and the gate switch 421. 422, and a control means 423 for determining whether the overvoltage protection condition is applicable based on the voltage across the smoothing capacitor 234, and controlling the gate switch 421 and the protection switch 422 based on the determination result. can do.

Preferably, the gate switch 421 may be one of a relay and a MOSFET, and the protection switch 422 may be one of a thyristor, a MOSFET, an IGBT, or a SiC MOSFET.

Here, the MOSFET has a small forward voltage reduction compared to the forward voltage reduction of the diode, so that the charging efficiency can be increased.

Preferably, as shown in FIG. 5B, the control means inputs a voltage across the smoothing capacitor 234 and outputs a voltage signal corresponding to the voltage across the smoothing capacitor 234. An electrically insulated isolated voltage meter, a voltage comparator for comparing the output of the isolated voltage meter with a predetermined reference voltage, a switch driver for controlling on or off of the protective switch and the gate switch based on the output of the voltage comparator, and a voltage A signal inverter may be provided between the output of the comparator and the switch driver for the gate switch 421.

In addition, a signal inverter may be provided between the output of the voltage comparator and the switch driver for the protection switch 422.

In addition, as shown in FIG. 5B, the control means inputs the voltage across the smoothing capacitor 234 and outputs the voltage signal corresponding to the voltage across the smoothing capacitor 234, but the input and the output are electrically An isolated isolated voltage meter, a voltage comparator for comparing the output of the isolated voltage meter with a predetermined reference voltage, a switch driver for controlling on or off of the protective switch and the gate switch based on the output of the voltage comparator, and a voltage comparator A signal inverter may be provided between the output and the switch driver for the gate switch 421.

In addition, as shown in FIG. 5C, the control means includes a proportional voltage (a node voltage) of the DC link voltage N0 and a G node, a predetermined first voltage Vref_high, and a second voltage Vref_low. Compare and generate on or off signals SW1 and 2 of the protection switch and the gate switch based on the comparison.

Here, the node a voltage can generate a voltage proportional to the DC link voltage using a plurality of resistors, as shown in FIG. 5C.

Here, the node a voltage, as shown in FIG. 5D, may generate a voltage proportional to the DC link voltage using one resistor, a zener diode, and a capacitor.

Further, as shown in Fig. 5E, the control means selects the predetermined first voltage Vref_high and the second voltage Vref_low, and turns off the SW1 terminal when the DC link voltage is lower than the lower limit of the battery voltage usage range. And a hysteresis property such that the DC link voltage generates an on signal to the switch SW1 terminal at a voltage higher than the upper limit of the battery voltage usage range.

In addition, since the auxiliary power supply for supplying the power of the control means must operate even when the power is not supplied, the auxiliary power can be connected to the smoothing capacitor to obtain the power.

In addition, when the protection switch is turned on, the smoothing capacitor is gradually discharged by the power consumed by the auxiliary power supply. When the protection switch is lower than the lower reference voltage of the hysteresis, the protection switch is turned off and the gate switch is turned on to increase the smoothing capacitor voltage again. The ground side inverter can then be notified to stop the ground side inverter.

Embodiment 3

As shown in FIG. 6, the non-contact power receiving device 230 including the overvoltage preventing means for an electric vehicle is provided inside the electric vehicle and includes the power receiving unit 231 and the power receiving unit 231 which receive electric power from the non-contact power feeding device. Filter unit 232 connected to the output, rectifier 233 connected to the output of the filter unit 232, smoothing capacitor 234 connected to the DC link (N0) connected to the output of the rectifier 233 and the battery main relay 302 The output of the filter unit 232 is connected to one side, and the negative electrode and the other side of the smoothing capacitor 234 includes an overvoltage preventing means 430, the overvoltage preventing means 430, the voltage of the smoothing capacitor 234 By blocking the charging and discharging currents of the smoothing capacitor 234 to prevent overvoltage from occurring in the smoothing capacitor 234, and constructing a closed loop path through which the current received from the non-contact power supply device 101 can flow. The rate of change of received current is below a predetermined value Can be

In the present embodiment, the overvoltage protection means 430 includes first and

second protection diodes

431 and 432 having an anode connected to the input nodes N2 and N3 of the rectifying unit 233, and one side of the first and

second protection diodes

431 and 432. Based on the voltage of the protection switch 433 and the smoothing capacitor 234 connected in common with the cathodes of the

diodes

431 and 432 and the other side connected to the ground G, it is determined whether the overvoltage protection condition is applicable, and the determination result. Control means 434 for controlling the protection switch 433 based on the.

In addition, the outputs N2 and N3 of the filter unit 232 may have a sine wave shape, and when the voltage difference between N2 and N3 is V23, if V23 is a positive value, the first protection diode 431 and the protection switch ( 433) and a lower diode (so that current flows from G to N3) of one arm of the rectifier can be conducted, and if V23 is a negative value, the second protection diode 432, the protection switch 433, and the other arm of the rectifier The bottom diode of G (so that current flows from G to N2) may be conducted.

Embodiment 4

In a non-contact charging system having an overvoltage protection function for an electric vehicle including a non-contact power receiver and a non-contact power supply as described above, the non-contact power supply includes a measuring unit for measuring the amount of power or current supplied by the non-contact power supply during charging, measurement In the case where the amount of power or the current amount smaller than the predetermined reference value lasts for a predetermined time, the determination unit that determines that the overvoltage protection function of the non-contact power receiving device 230 is performed, and the supply of the charging power is stopped based on the result of the determination. It may include a control unit for controlling the non-contact power supply device.

In this embodiment, when the overvoltage protection function is operated, the rectifier input terminal voltage of the power receiving device can be zero, and therefore, the output current of the power feeding device can also be 0, and the output current of the power feeding device is maintained at 0 for a predetermined time. In this case, the operation of the power supply device can be stopped for overvoltage protection without the separate communication between the power supply device and the power reception device or the power supply device and the vehicle control period.

In addition, the predetermined reference value is an average value of the measured amount of electric power or amount of electric current during a predetermined previous time from the time when the charge amount SOC of the battery 301 of the electric vehicle, the amount of electric power or the amount of electric current is measured, and the information provided by the controller of the electric vehicle. It may be determined based on at least one of the. According to such a configuration, it is possible to quickly determine whether the overvoltage protection function is operating, and to prevent a current such as heat generation and a decrease in life due to the continuous flow of current through a protection switch.

In addition, the predetermined previous time may be set within a range of 30 seconds to 30 minutes.

As described above, the present invention has been described by specific embodiments such as specific components and the like. However, this is merely provided to help a more general understanding of the present invention, and the present invention is limited to the above embodiment. However, various modifications and variations are possible to those skilled in the art to which the present invention pertains.

Therefore, the spirit of the present invention should not be limited to the described embodiments, and all the things equivalent to or equivalent to the claims as well as the following claims will fall within the scope of the present invention. .

[Description of the code]

100: non-contact power supply device

101: (LC type) non-contact power supply device

102: (LCCL type) non-contact power feeding device

103: (equivalent) sine wave current source

200: non-contact receiving device

210: LC contactless power receiver

220: LCCL non-contact receiving device

230: power receiver

231: faucet

232: filter unit

233: rectifier

234: smoothing capacitor

301: Battery

302: Battery Main Relay

410, 420, 430: overvoltage protection means

411: series diode

412, 422: protection switch

421: Gate Switch

431: first protection diode

432: second protection diode

433: protection switch

434: switch control means

Claims

A non-contact power receiver comprising an overvoltage protection means for an electric vehicle,

The non-contact receiving device,

It is provided in the inside of an electric vehicle;

A power receiving unit receiving electric power from the non-contact power supply device;

A filter unit connected to an output of the power receiving unit;

A rectifier connected to the output of the filter unit;

Overvoltage protection means connected to the output of said rectifier; And

A smoothing capacitor connected to the DC link to which the overvoltage preventing means and the battery main relay are connected;

Including,

The overvoltage prevention means,

Blocking the charging current and the discharge current of the smoothing capacitor based on the voltage of the smoothing capacitor to prevent the overvoltage from occurring in the smoothing capacitor, and configure a closed loop path through which the current received from the non-contact power supply device can flow Such that the rate of change of the received current is equal to or less than a predetermined value;

Non-contact power receiving device having an over-voltage protection function for an electric vehicle.
The method of claim 1,

The overvoltage prevention means

A series diode provided between the rectifier and the smoothing capacitor;

A protection switch provided in parallel between the rectifier and the series diode; And

Control means for determining whether an overvoltage protection condition is applicable based on the voltage of the smoothing capacitor and controlling the protection switch based on the determination result;

Non-contact power receiving device having an over-voltage protection function for an electric vehicle comprising a.
The method of claim 2,

The series diode

An output of the rectifier and an anode side of the series diode are connected;

An anode of the smoothing capacitor and a cathode of the series diode are connected;

When the protection switch is turned on (closed), the node, which is an output of the rectifier, and the positive electrode (+) of the smoothing capacitor are electrically separated to prevent current from flowing between the rectifier and the protection switch and the smoothing capacitor. that;

Non-contact power receiving device having an over-voltage protection function for an electric vehicle.
The method of claim 1,

The overvoltage prevention means

A gate switch provided between the rectifier and the smoothing capacitor;

A protection switch provided in parallel between the rectifier and the gate switch; And

And controlling means for determining whether an overvoltage protection condition is applicable based on the voltage across the smoothing capacitor, and controlling the gate switch and the protection switch based on the determination result. Non-contact receiving device having a.
The method of claim 4, wherein

The gate switch is one of a relay, a MOSFET,

The protection switch is a relay, a thyristor, a MOSFET, an IGBT, a non-contact receiving apparatus having an overvoltage protection function for an electric vehicle, characterized in that one of.
The method of claim 4, wherein

The control means

An input voltage and a voltage signal corresponding to both voltages of the smoothing capacitor as outputs, the input and output of the smoothing capacitor being electrically insulated;

A voltage comparator comparing the output of the isolated voltage meter with a predetermined reference voltage;

A switch driver for controlling on or off of the protection switch and the gate switch based on an output of the voltage comparator; And

And a signal inverter between an output of the voltage comparator and the switch driver for the gate switch.
In a non-contact power receiving device including an overvoltage protection means for an electric vehicle,

The non-contact receiving device,

It is provided in the inside of an electric vehicle;

A power receiving unit receiving electric power from the non-contact power supply device;

A filter unit connected to an output of the power receiving unit;

A rectifier connected to the output of the filter unit;

A smoothing capacitor connected to a DC link to which the output of the rectifier and the battery main relay are connected; And

And an overvoltage preventing means connected at one side of the output of the filter unit and connected to a cathode of the smoothing capacitor and the other side of the smoothing capacitor;

The overvoltage prevention means

Blocks the charging current and the discharge current of the smoothing capacitor based on the voltage of the smoothing capacitor to prevent overvoltage from occurring in the smoothing capacitor, and configures a closed loop path through which a current received from a non-contact power supply device can flow. A non-contact power receiver having an overvoltage protection function for an electric vehicle, wherein the rate of change of the received electric current is equal to or less than a predetermined value.
The method of claim 7, wherein

The overvoltage prevention means

First and second protection diodes each having an anode connected to the input nodes N2 and N3 of the rectifier;

A protection switch having one side connected in common with the cathodes of the first and second protection diodes and the other side connected with the ground (G); And

Control means for determining whether an overvoltage protection condition is applicable based on the voltage of the smoothing capacitor and controlling the protection switch based on the determination result;

Non-contact power receiving device having an over-voltage protection function for an electric vehicle comprising a.
The method according to claim 2 or 8,

The control means

An input voltage and a voltage signal corresponding to both voltages of the smoothing capacitor as outputs, the input and output of the smoothing capacitor being electrically insulated;

A voltage comparator comparing the output of the isolated voltage meter with a predetermined reference voltage; And

And a switch driver configured to control on or off of the protection switch based on the output of the voltage comparator.
The method according to any one of claims 2, 4, and 8,

Whether the overvoltage protection condition is applicable

Non-contact power receiving device having an over-voltage protection function for an electric vehicle, characterized in that it is determined that the change rate of the voltage across the smoothing capacitor exceeds a predetermined value.
A non-contact charging system having an overvoltage protection function for an electric vehicle, comprising the non-contact power receiving device of any one of claims 2, 4, and 8, and a non-contact power supply device.

The non-contact power supply device,

A measuring unit which measures the amount of power or current supplied by the non-contact power feeding device during charging;

A determination unit that determines that the overvoltage protection function of the non-contact power receiver is performed when the state of the measured amount of power or current is smaller than a predetermined value for a predetermined time; And

A control unit controlling the non-contact power supply device such that the supply of charging power is stopped based on a result of the determination;

Non-contact power supply having an overvoltage protection function for an electric vehicle comprising a.