JP6115077B2 - Non-contact power feeding device - Google Patents

Description

  The present invention relates to a non-contact power feeding device.

  2. Description of the Related Art Conventionally, a non-contact power supply device that supplies power in a non-contact manner by magnetic coupling of a pair of coils is known (for example, see Patent Document 1). Application of this non-contact power supply apparatus to an electric vehicle such as an electric vehicle is being promoted. For example, one coil connected to an AC power supply is installed in a parking space such as a power supply stand, and the other coil connected to a battery is installed in an electric vehicle. And by using the coil on the parking space side as the primary side coil and the coil on the electric vehicle side as the secondary side coil, one coil and the other coil are connected from the AC power source on the parking space side to the battery on the vehicle side. Power can be supplied via.

JP 2011-72074 A

  By the way, a smoothing circuit including a capacitor is applied to the electric vehicle side of such a non-contact power feeding device in order to remove a pulsation component included in the electric power supplied from the secondary coil to the battery. In this case, there is a problem that an inrush current is generated by turning on a switch for performing electrical connection and disconnection between the secondary coil and the battery.

  The present invention has been made in view of such circumstances, and an object of the present invention is to effectively suppress an inrush current when electrically connecting a secondary coil and a battery in a non-contact power feeding device. It is.

In order to solve such a problem, the present invention provides a non-contact power supply device that supplies power in a non-contact manner from a primary coil installed in a vehicle space to a secondary coil mounted on a vehicle by magnetic coupling. . In this case, the control unit of the non-contact power supply apparatus determines whether the difference between the voltage across the secondary battery and the voltage across the capacitor is the determination threshold in a state where the secondary coil and the secondary battery are electrically disconnected. If the difference exceeds the determination threshold, the number of times that the difference exceeds the determination threshold reaches a predetermined number of times set in advance, the primary coil and the secondary coil If it is determined that there is a positional deviation between the two, and the difference is equal to or less than the determination threshold , power is supplied from the primary side coil to the secondary side coil, and the power is output from the secondary side coil. There is judged to have been charged, controls the switching unit to the connected state.

  According to the present invention, it is possible to charge the capacitor connected to the secondary coil by transmitting power from the primary coil. Thereby, in a state in which the capacitor is charged, the switch unit is controlled to be in a connected state, so that an inrush current can be effectively suppressed.

Block diagram schematically showing the configuration of the non-contact power supply system Circuit diagram schematically showing the configuration of the vehicle side Flowchart showing a procedure of processing related to vehicle charging control

  FIG. 1 is a block diagram schematically showing the configuration of the non-contact power feeding system according to this embodiment. The non-contact power supply system includes a power supply device 100 that is a ground-side unit and an electric vehicle (hereinafter simply referred to as “vehicle”) 200 including a vehicle-side unit, and supplies power from the power supply device 100 in a non-contact manner. It is the system which charges the battery 28 provided in (non-contact electric power feeder).

  The power supply apparatus 100 is installed in a charging stand or the like provided with a parking space for the vehicle 200 and supplies power to the vehicle 200. The power supply apparatus 100 is mainly configured by a power control unit 11, a power transmission coil 12, a wireless communication unit 14, and a control unit 15.

  The power control unit 11 is a circuit for converting AC power transmitted from the AC power source 300 into high-frequency AC power and transmitting the power to the power transmission coil 12. The power control unit 11 includes a rectification unit 111, a PFC (Power Factor Correction) circuit 112, an inverter 113, and a sensor 114.

  The rectifying unit 111 is electrically connected to the AC power supply 300 and rectifies output AC power from the AC power supply. The PFC circuit 112 is a circuit for improving the power factor by shaping the output waveform from the rectifying unit 111, and is connected between the rectifying unit 111 and the inverter 113. The inverter 113 is a power conversion device including a switching element such as a smoothing capacitor and IGBT, a PWM control circuit, and the like. The inverter 113 converts DC power into high-frequency AC power based on a control signal from the control unit 15, and transmits the power transmission coil 12. To supply. The sensor 114 is connected between the PFC circuit 112 and the inverter 113 and detects current and voltage.

  The power transmission coil 12 is a coil for supplying electric power in a non-contact manner to the power reception coil 22 on the vehicle 200 side, and has a structure in which a conductive wire made of a conductor such as metal is spirally wound in a predetermined plane. doing. The power transmission coil 12 is provided at a target location such as a parking space where the vehicle 200 is parked, and faces the lower side of the power receiving coil 22 on the vehicle 200 side when the vehicle 200 is parked at a specified position in the parking space.

  The wireless communication unit 14 performs bidirectional communication with the wireless communication unit 24 provided on the vehicle 200 side. Since the communication frequency between the wireless communication unit 14 and the wireless communication unit 24 is set to a frequency higher than the frequency used in the vehicle peripheral device such as intelligence ski, the wireless communication unit 14 and the wireless communication unit 24 Even if it communicates between, vehicle peripheral devices are hard to receive the interference by the said communication. For communication between the wireless communication unit 14 and the wireless communication unit 24, for example, various wireless LAN methods are used, and communication methods suitable for long distances are used.

  The control unit 15 has a function of controlling the power supply apparatus 100. For example, the control unit 15 controls the power control unit 11, the power transmission coil 12, and the wireless communication unit 14. The control unit 15 transmits a control signal to start power supply to the vehicle 200 side or receives power from the vehicle 200 side through communication between the wireless communication unit 14 and the wireless communication unit 24. Receive control signals. The control unit 15 performs switching control of the inverter 113 based on the detection current of the sensor 114 and controls electric power supplied from the power transmission coil 12. As the control unit 15, a microcomputer mainly composed of a CPU, a ROM, a RAM, and an I / O interface can be used.

  The vehicle 200 includes a power receiving coil 22, a wireless communication unit 24, a charging control unit 25, a rectifying unit 26, a relay unit 27, a battery 28, an inverter 29, a motor 30, and a notification unit 32. Yes.

The power reception coil 22 is a coil for receiving electric power in a non-contact manner from the power transmission coil 12 on the power supply apparatus 100 side, and has a structure in which a conductive wire made of a conductor such as metal is wound in a spiral shape. The power receiving coil 22 is provided at a target location, for example, between the rear wheels on the bottom surface (chassis) or the like of the vehicle 200, and when the vehicle 200 is parked at a specified position in the parking space, It faces the upper side of the power transmission coil 12.

  The wireless communication unit 24 performs bidirectional communication with the wireless communication unit 14 provided on the power supply apparatus 100 side.

  The rectifying unit 26 is connected to the power receiving coil 22 and is configured by a rectifying circuit that rectifies AC power received by the power receiving coil 22 into direct current.

  The relay unit 27 includes a relay switch that is switched on and off under the control of the charging control unit 25. The relay unit 27 can disconnect the high-power system including the battery 28 from the low-power system of the power receiving coil 22 and the rectifying unit 26 serving as a charging circuit unit by turning off the relay switch.

  The battery 28 is a power source of the vehicle 200 and is configured by electrically connecting a plurality of secondary batteries, for example.

  The inverter 29 is a power conversion device that includes a switching element such as an IGBT, a PWM control circuit, and the like. The inverter 29 converts the DC power output from the battery 28 into AC power based on the control signal, and converts the AC power to the motor 30. Supply. The motor 30 is composed of, for example, a three-phase AC motor, and is a drive source for driving the vehicle 200.

  The notification unit 32 includes a warning lamp, a display of a navigation system, a speaker, and the like, and is arranged on an instrument panel or the like in the vehicle interior. The notification unit 32 outputs light, an image, sound, or the like to the user based on the control by the charging control unit 25.

  The charging control unit 25 has a function of controlling charging of the battery 28. For example, the charging control unit 25 controls the wireless communication unit 24 and the notification unit 32. The charging control unit 25 receives a control signal for starting power supply from the power supply apparatus 100 side through communication of the wireless communication unit 24 and the wireless communication unit 14, or receives a control signal for receiving power from the vehicle 200 side. Or send to.

  Although not shown, the charging control unit 25 is connected to a controller that controls the entire vehicle 200 via a CAN communication network. The controller manages the switching control of the inverter 29 and the state of charge (SOC) of the battery 28. When the charging control unit 25 determines full charging based on the SOC of the battery 28 obtained from the controller, the charging control unit 25 transmits a control signal to the power supply apparatus 100 to end charging.

  In the non-contact power feeding system according to the present embodiment, high-frequency power is transmitted between the power transmission coil 12 and the power receiving coil 22 in a non-contact state by electromagnetic induction. In other words, when a voltage is applied to the power transmission coil 12 that is the primary side coil, magnetic coupling occurs between the power transmission coil 12 and the power reception coil 22, and the power transmission coil 12 to the power reception coil 22 that is the secondary side coil. Power is supplied.

FIG. 2 is a circuit diagram schematically showing the configuration of the vehicle 200 side. As shown in the figure, the battery 28 is connected in series with the power receiving coil 22 and charges the power output from the power receiving coil 22. A smoothing unit 37 is connected between the power receiving coil 22 and the battery 28, and is connected between the terminals of the power receiving coil 22 via the rectifying unit 26. The smoothing unit 37 is a circuit that removes pulsating components contained in the DC power output from the rectifying unit 26, and includes, for example, a choke coil L and a pair of capacitors C.

  The relay unit 27 is connected between the smoothing unit 37 and the battery 28, the relay switch 33 provided in a path from the power receiving coil 22 to the positive electrode of the battery 28, and the negative electrode of the battery 28 to the power receiving coil 22. And a relay switch 34 provided on the route to These relay switches 33 and 34 are switched on (connected state) and off (cut off state) by the charging control unit 25.

  As one of the features of the present embodiment, the charging control unit 25 controls the relay switches 33 and 34 to be off when no power is supplied. On the other hand, when receiving power supply from the power transmission coil 12, the charging relay unit 27 supplies power supplied from the power transmission coil 12 to the power reception coil 22 to the capacitor C of the smoothing unit 37, and the capacitor C is charged. If it is determined, the relay switches 33 and 34 are turned on.

  Further, detection signals from the first voltage detection sensor 35 and the second voltage detection sensor 36 are input to the charge control unit 25. The first voltage detection sensor 35 detects the voltage across the capacitor C in the smoothing unit 37, and the second voltage detection sensor 36 detects the voltage across the battery 28. Thereby, the charge control unit 25 can recognize the voltage Vch across the capacitor C of the smoothing unit 37 and the voltage Vbt across the battery 28.

  FIG. 3 is a flowchart showing a procedure of processing relating to charging control of the vehicle 200 according to the present embodiment. The processing shown in this flowchart is called by the completion of parking in the parking space of the charging stand as a trigger, and is executed by the charging control unit 25. Whether the vehicle 200 has completed parking in the parking space is determined by, for example, the distance from the parking space determined by the wireless communication unit 24 based on the electric field strength of the signal received from the wireless communication unit 14 of the power supply apparatus 100. This can be done from information such as the operating state of the parking brake. Here, the relay switches 33 and 34 of the relay unit 27 are in an OFF state.

  First, in step 1 (S1), the charging control unit 25 receives a trial power supply start signal from the control unit 15 of the power supply apparatus 100 via communication between the wireless communication unit 24 and the wireless communication unit 14 of the power supply apparatus 100. Receive. This trial power feeding is power feeding performed before starting regular power feeding, and is performed with power smaller than that of regular power feeding. When the control unit 15 of the power supply apparatus 100 transmits a trial power supply start signal, the control unit 15 controls the power control unit 11 and outputs the specified power corresponding to the trial power supply from the power transmission coil 12. Therefore, after receiving the start signal of the trial power feeding, the power receiving coil 22 is in a state where the power from the power transmitting coil 12 is input.

  In addition, as a method for determining that power transmission from the power transmission coil 12 is started, not only receiving a trial power feeding start signal but also determining from the rise of the voltage based on the voltage Vch across the capacitor C. Also good.

  In step 2 (S2), the charging control unit 25 reads the detection signals from the first voltage detection sensor 35 and the second voltage detection sensor 36, and the voltage Vbt across the battery 28 and the voltage across the capacitor C of the smoothing unit 37. It is determined whether or not the difference from Vch is equal to or less than a determination threshold value ΔV. This determination threshold value ΔV is set so that the voltage across the capacitor C of the smoothing unit 37 charged by the power from the power receiving coil 22 is the voltage across the battery 28 from the viewpoint of suppressing the inrush current when the relay switches 33 and 34 are turned on. It is a value for determining whether it is the same as Vbt or in a range that can be regarded as the same, and an optimum value is set in advance through experiments and simulations.

If an affirmative determination is made in step 2, that is, if the voltage difference (Vbt−Vch) is equal to or less than the determination threshold value ΔV, the process proceeds to step 3 (S3). On the other hand, if a negative determination is made in step 2, that is, if the voltage difference (Vbt−Vch) is larger than the determination threshold value ΔV, the process proceeds to step 7 (S7) described later.

  In step 3, the charging control unit 25 controls the relay switches 33 and 34 of the relay unit 27 to be turned on. In addition, the charging control unit 25 notifies the control unit 15 of the power supply apparatus 100 that the relay switches 33 and 34 are turned on via communication between the wireless communication unit 24 and the wireless communication unit 14 of the power supply apparatus 100. To do. When receiving the notification, the control unit 15 of the power supply apparatus 100 controls the power control unit 11 to switch the output from the power transmission coil 12 from the specified power at the time of trial power supply to the specified power at the time of regular power supply.

  In step 4, the charging control unit 25 performs regular power feeding. Specifically, the charging control unit 25 receives power output from the power transmission coil 12 by the power receiving coil 22 and stores the power in the battery 28.

  In step 5, the charge control unit 25 determines whether or not the charge amount of the battery 28 has reached full charge. If an affirmative determination is made in step 5, that is, if the amount of charge of the battery 28 has reached full charge, the process proceeds to step 6 (S6). On the other hand, if a negative determination is made in step 5, that is, if the charge amount of the battery 28 has not reached full charge, the process returns to step 4.

  In step 7, the charging control unit 25 notifies the control unit 15 of the power supply apparatus 100 of the end of power supply via communication between the wireless communication unit 24 and the wireless communication unit 14 of the power supply apparatus 100. In response to this notification, the control unit 15 of the power supply apparatus 100 controls the power control unit 11 to end the output of power from the power transmission coil 12.

  On the other hand, in step 7 following the negative determination in step 2, the charging control unit 25 determines whether or not the number of negative determinations in the determination in step 2 has reached a preset specified number of times. If the capacitor C of the smoothing unit 37 is normally charged by the trial power supply, an affirmative determination is made in step 2. Therefore, the situation where the negative determination is continuously made in the process of step 2 is caused by the fact that the power supply is not normally performed. For example, when a positional deviation occurs between the power transmission coil 12 and the power reception coil 22, the power feeding efficiency is lowered, so that the power charged in the capacitor C and the power discharged from the capacitor C are balanced, It is possible that the voltage on the capacitor C does not increase. Further, when there is a foreign object or the like between the power transmission coil 12 and the power reception coil 22 or when there is a circuit abnormality, the power supply efficiency is lowered, and similarly, the voltage of the capacitor C may not increase.

  Therefore, in step 7, based on the number of times that the negative determination is made in step 2, the elapsed time since the power is supplied from the power transmission coil 12 is observed, thereby determining whether or not the power supply is normal. I am going to do that. If an affirmative determination is made in step 7, that is, if the number of negative determinations reaches the specified number, the process proceeds to step 8 (S8). On the other hand, if a negative determination is made in step 7, that is, if the number of negative determinations does not reach the specified number, the process returns to step 2.

  In step 8, the charging control unit 25 controls the notification unit 32 to notify the user that power feeding is abnormal, and proceeds to the processing in step 6 described above.

As described above, in the present embodiment, the charging control unit 25 supplies power from the power transmission coil 12 to the power receiving coil 22 and outputs the power from the power receiving coil 22 when the relay switches 33 and 34 of the relay unit 27 are off. When it is determined that the capacitor C of the smoothing unit 37 is charged by electric power, the relay switches 33 and 34 of the relay unit 27 are controlled to be turned on.

  According to this configuration, the capacitor C of the smoothing unit 37 can be charged by transmitting power from the power transmission coil 12. Thereby, in a state where the capacitor C of the smoothing unit 37 is charged, the relay switches 33 and 34 of the relay unit 27 are turned on, so that the inrush current can be effectively suppressed.

  In the present embodiment, the charging control unit 25 determines that the capacitor C is charged based on the voltage Vch across the capacitor C of the smoothing unit 37 and the voltage Vbt across the battery 28.

  By matching the voltages before and after the relay unit 27, the inrush current is suppressed. Thus, by monitoring the voltage Vch across the capacitor C of the smoothing unit 37 and the voltage Vbt across the battery 28, it can be determined that the capacitor C has been charged within a range where the inrush current can be suppressed. it can.

  In the present embodiment, the relay switch 33 of the relay unit 27 includes a connection point for connecting in parallel a precharge circuit for supplying the power of the battery 28 to the capacitor C of the smoothing unit 37 via a resistor. Absent.

  According to the present embodiment, the capacitor C of the smoothing unit 37 can be charged by receiving the power transmitted from the power transmission coil 12 to the power reception coil 22. Thereby, the structure which abbreviate | omitted the precharge circuit for charging the capacitor | condenser C of the smoothing part 37 is employable.

  Further, in the present embodiment, the charging control unit 25 includes the power transmission coil 12 and the power receiving coil 22 based on the voltage Vch across the capacitor C of the smoothing unit 37 and the elapsed time since power is supplied from the power transmission coil 12. Is determined to be abnormal.

  According to such a configuration, the voltage Vch across the capacitor C of the smoothing unit 37 can be monitored for a certain period after the power is supplied from the power transmission coil 12, so that the power transmission coil 12, the power reception coil 22, It is possible to effectively determine a power feeding abnormality such as a positional deviation of the current and the presence of foreign matter.

  In the present embodiment, the charging determination of the capacitor C of the smoothing unit 37 is performed based on the voltage Vch across the capacitor C of the smoothing unit 37 and the voltage Vbt across the battery 28, but is not limited thereto. For example, the charge control unit 25 may determine that the capacitor C has been charged based on the elapsed time since the power is supplied from the power transmission coil 12. Thereby, the charge determination of the capacitor | condenser C can be performed by a method simply. In this case, the start timing for counting the elapsed time may be the reception of the trial power supply start signal as described above. Further, the rise of the voltage may be determined as long as the voltage Vch across the capacitor C can be detected.

  As mentioned above, although the non-contact electric power feeder which concerns on embodiment of this invention was demonstrated, it cannot be overemphasized that a various deformation | transformation is possible within the scope of the invention, without this invention being limited to embodiment mentioned above. Absent.

DESCRIPTION OF SYMBOLS 100 Electric power feeder 11 Power control part 12 Power transmission coil 14 Wireless communication part 15 Control part 200 Vehicle 22 Power reception coil 24 Wireless communication part 25 Charging control part 26 Rectification part 27 Relay part 28 Battery 29 Inverter 30 Motor 32 Notification part 33 Relay switch 34 Relay Switch 35 First voltage detection sensor 36 Second voltage detection sensor 37 Smoothing unit C Capacitor L Choke coil

Claims (2)

In a non-contact power feeding device that supplies power in a non-contact manner from a primary coil installed in a vehicle space by magnetic coupling to a secondary coil mounted on a vehicle,
The secondary coil facing the primary coil;
A secondary battery connected in series with the secondary coil and charging power output from the secondary coil;
A capacitor connected between the secondary coil and the secondary battery and connected between terminals of the secondary coil;
A switch unit connected between the capacitor and the secondary battery, for electrical connection and disconnection between the secondary coil and the secondary battery;
A control unit for controlling the switch unit,
The control unit determines whether or not a difference between a voltage across the secondary battery and a voltage across the capacitor is equal to or less than a determination threshold in the cutoff state of the switch, and the difference is less than or equal to the determination threshold. And when the number of times the difference exceeds the determination threshold reaches a predetermined number of times set in advance, it is determined that a positional deviation has occurred between the primary side coil and the secondary side coil, If the difference is equal to or smaller than the determination threshold value, it is determined that the capacitor by the power which the power from the primary coil to the secondary coil is output supplied from the secondary coil is charged, the A non-contact power feeding device, wherein the switch unit is controlled to be connected. In a non-contact power feeding device that supplies power in a non-contact manner from a primary coil installed in a vehicle space by magnetic coupling to a secondary coil mounted on a vehicle,
The secondary coil facing the primary coil;
A secondary battery connected in series with the secondary coil and charging power output from the secondary coil;
A capacitor connected between the secondary coil and the secondary battery and connected between terminals of the secondary coil;
A switch unit connected between the capacitor and the secondary battery, for electrical connection and disconnection between the secondary coil and the secondary battery;
A control unit for controlling the switch unit,
The control unit determines whether or not a difference between a voltage across the secondary battery and a voltage across the capacitor is equal to or less than a determination threshold in the cutoff state of the switch, and the difference is less than or equal to the determination threshold. And when the number of times the difference exceeds the determination threshold reaches a predetermined number of times set in advance, it is determined that there is a foreign object between the primary side coil and the secondary side coil, and the difference There wherein if: determination threshold, determines that the capacitor by the power which the power from the primary coil to the secondary coil is output from the supply of the secondary coil is charged, the switch A non-contact power feeding device that controls the unit to a connected state.

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