JP5664544B2 - Non-contact power receiving device and non-contact charging system - Google Patents

Description

  The present invention relates to a contactless power receiving device and a contactless charging system.

  In recent years, in order to reduce carbon dioxide emitted from automobiles in order to prevent global warming, electric cars and hybrid cars that use electric energy instead of or in addition to fuels have attracted attention. . In addition, plug-in hybrid vehicles that are configured so that electric energy can be charged from the outside of the vehicle to the battery mounted in the hybrid vehicle have also appeared.

  However, connecting the charging cable when supplying power to the automobile from the outside takes extra time for the user. For this reason, a non-contact power supply system that can start charging without taking time and effort to connect a cable when a vehicle is parked at a predetermined position is also being studied.

  Japanese Patent Laying-Open No. 2011-135729 (Patent Document 1) discloses that in a non-contact charging system, the temperature of a resonance coil is measured and a cooling device is operated based on the measured temperature.

JP 2011-135729 A JP 2011-125184 A

  In measuring the coil temperature, in the method of directly measuring the temperature with the sensor, the metal member of the sensor and the coil are brought into close contact with each other, so that the power receiving efficiency in the coil may be reduced. Moreover, when using a non-contact measuring device such as an optical sensor, the measuring device is expensive. Indirectly measuring the temperature, for example, when measuring the ambient temperature of the coil, there are problems such as an increase in measurement error.

  Furthermore, in the non-contact charging system, the positions of the power reception unit and the power transmission unit may be different each time, the charging efficiency may vary, and the amount of heat generated by each device may also change. Therefore, it is preferable to optimize the cooling of each device.

  An object of the present invention is to provide a non-contact power receiving apparatus and a non-contact charging system capable of improving the accuracy of the measured temperature while suppressing an increase in the cost of the temperature measuring apparatus for electrical equipment related to non-contact power transmission and reception. .

  In summary, the present invention is a non-contact power receiving device that is configured to be capable of receiving power in a non-contact manner, and is connected to the power receiving unit based on parameters related to power receiving efficiency of the power receiving unit. And a controller for estimating the temperature of the electrical equipment.

  Preferably, the control device controls the cooling device for the electric device based on a parameter related to power reception efficiency.

  More preferably, the cooling device includes a first cooling device that cools the power receiving unit, and a second cooling device that cools the power storage device charged by the power received by the power receiving unit. The control device controls the cooling capacity of the first and second cooling devices according to the power receiving efficiency in the power receiving unit.

  More preferably, the power received by the power receiving unit is rectified by a rectifier and supplied to the power storage device. The cooling device further includes a third cooling device that cools the rectifier. The control device further controls the cooling capacity of the third cooling device according to the power receiving efficiency in the power receiving unit.

  More preferably, the control device increases the cooling capacity of the first cooling device when the power receiving efficiency in the power receiving unit is lower than a predetermined value, as compared with the case where the power receiving efficiency is higher than the predetermined value, and the second or second 3 cooling capacity of the cooling device is reduced.

  Preferably, the non-contact power receiving device further includes a temperature measuring device that estimates or detects the temperature of the electric device. The control device stops charging the power storage device via the power receiving unit when the measured value by the temperature measuring device is different from the estimated value estimated based on the parameter related to the power receiving efficiency of the power receiving unit.

  In another aspect, the present invention is a non-contact charging system, in which a first cooling device that cools a power transmission unit or a power reception unit, and a second cooling device that cools a power storage device that is charged by the power received by the power reception unit. A cooling device and a control device that controls the cooling capacity of the first and second cooling devices according to the power receiving efficiency in the power receiving unit are provided.

  Preferably, the power received by the power receiving unit is rectified by a rectifier and supplied to the power storage device. The contactless charging system further includes a third cooling device that cools the rectifier. The control device further controls the cooling capacity of the third cooling device according to the power receiving efficiency in the power receiving unit.

  More preferably, the control device increases the cooling capacity of the first cooling device when the power receiving efficiency in the power receiving unit is lower than a predetermined value, as compared with the case where the power receiving efficiency is higher than the predetermined value, and the second or second 3 cooling capacity of the cooling device is reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the temperature of the electric equipment regarding non-contact power transmission / reception can be measured or estimated with low cost and high precision.

1 is an overall configuration diagram of a non-contact power transmission / reception system 10 according to an embodiment of the present invention. It is a figure for demonstrating the principle of the power transmission by the resonance method. It is a detailed block diagram of the non-contact power transmission and reception system 10 shown in FIG. It is a figure for demonstrating a mode that the position shift occurred when the power receiving part 110 in FIG. 1 and FIG. 2 and the power transmission part were arrange | positioned facing each other. It is a figure for demonstrating the state of each site | part and control of a cooling device. It is a flowchart for demonstrating the control performed with a power transmission apparatus and a vehicle. It is a flowchart for demonstrating the abnormality determination process performed during charge. It is a flowchart for demonstrating an example of the control which changes the cooling capacity of a cooling device according to a power receiving efficiency.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

FIG. 1 is an overall configuration diagram of a non-contact power transmission / reception system 10 according to an embodiment of the present invention.
Referring to FIG. 1, contactless power transmission / reception system 10 includes a vehicle 100 and a power transmission device 200. Vehicle 100 includes a power reception unit 110 and a communication unit 160. The power transmission device 200 includes a high frequency power supply device 210, a power transmission unit 220, and a communication unit 230.

  The power receiving unit 110 is installed on the bottom surface of the vehicle body, and is configured to receive the power transmitted from the power transmitting unit 220 of the power transmitting device 200 in a contactless manner. Specifically, power reception unit 110 includes a coil (hereinafter referred to as a self-resonance coil, which may be appropriately called “resonance coil”) described later, and a self-resonance coil included in power transmission unit 220. Receiving power from the power transmission unit 220 in a non-contact manner by resonating via an electromagnetic field. Communication unit 160 is a communication interface for performing communication between vehicle 100 and power transmission device 200.

  The high frequency power supply device 210 converts commercial AC power supplied via, for example, the plug 212 into high frequency power and outputs the high frequency power to the power transmission unit 220. In addition, the high frequency power supply device 210 may receive power from a power supply device such as a solar power generation device or a wind power generation device.

  The power transmission unit 220 is installed on the floor of a parking lot, for example, and is configured to send the high frequency power supplied from the high frequency power supply device 210 to the power reception unit 110 of the vehicle 100 in a non-contact manner. Specifically, the power transmission unit 220 includes a self-resonant coil, and the self-resonant coil resonates with the self-resonant coil included in the power receiving unit 110 via an electromagnetic field, thereby transmitting power to the power receiving unit 110 in a non-contact manner. Communication unit 230 is a communication interface for performing communication between power transmission device 200 and vehicle 100.

  Here, when power is supplied from the power transmission device 200 of FIG. 1 to the vehicle 100, it is necessary to perform alignment between the power receiving unit 110 and the power transmission unit 220 of the vehicle 100 by guiding the vehicle 100 to the vicinity of the power transmission unit 220. That is, the vehicle 100 is not easily aligned. In the portable device, the user can easily lift it by hand and place it at an appropriate position of a power supply unit such as a charger. However, it is necessary for the user to operate the vehicle to stop the vehicle at an appropriate position, and fine position adjustment is difficult.

  The resonance method using an electromagnetic field can transmit relatively large power even if the transmission distance is several meters. For this reason, in the non-contact power transmission and reception system 10 according to this embodiment, power is supplied from the power transmission device 200 to the vehicle 100 using the resonance method.

  In the contactless power transmission and reception system according to the present embodiment, the natural frequency of power transmission unit 220 and the natural frequency of power reception unit 110 are the same natural frequency.

  The “natural frequency of the power transmission unit” means a vibration frequency when an electric circuit including a coil and a capacitor of the power transmission unit vibrates freely. In addition, in the electric circuit including the coil and the capacitor of the power transmission unit, the natural frequency when the braking force or the electric resistance is zero or substantially zero is referred to as “the resonance frequency of the power transmission unit”.

  Similarly, the “natural frequency of the power reception unit” means a vibration frequency when the electric circuit including the coil and the capacitor of the power reception unit freely vibrates. In addition, in the electric circuit including the coil and the capacitor of the power receiving unit, the natural frequency when the braking force or the electric resistance is zero or substantially zero is referred to as “the resonance frequency of the power receiving unit”.

  In this specification, the “same natural frequency” includes not only completely the same case but also the case where the natural frequencies are substantially the same. “The natural frequency is substantially the same” means that the difference between the natural frequency of the power transmission unit and the natural frequency of the power reception unit is within ± 10% of the natural frequency of the power transmission unit or the natural frequency of the power reception unit.

FIG. 2 is a diagram for explaining the principle of power transmission by the resonance method.
Referring to FIG. 2, in this resonance method, in the same way as two tuning forks resonate, two LC resonance coils having the same natural frequency resonate in an electromagnetic field (near field), and thereby, from one coil. Electric power is transmitted to the other coil via an electromagnetic field.

  Specifically, the primary coil 320 is connected to the high-frequency power source 310, and high-frequency power is supplied to the primary self-resonant coil 330 that is magnetically coupled to the primary coil 320 by electromagnetic induction. The primary self-resonant coil 330 is an LC resonator having an inductance and stray capacitance of the coil itself, and resonates with a secondary self-resonant coil 340 having the same resonance frequency as the primary self-resonant coil 330 via an electromagnetic field (near field). . Then, energy (electric power) moves from the primary self-resonant coil 330 to the secondary self-resonant coil 340 via the electromagnetic field. The energy (electric power) transferred to the secondary self-resonant coil 340 is taken out by the secondary coil 350 magnetically coupled to the secondary self-resonant coil 340 by electromagnetic induction and supplied to the load 360. Note that power transmission by the resonance method is realized when the Q value indicating the resonance intensity between the primary self-resonant coil 330 and the secondary self-resonant coil 340 is greater than 100, for example.

  In the contactless power transmission and reception system according to the present embodiment, power is transmitted from the power transmission unit to the power reception unit by resonating the power transmission unit and the power reception unit with an electromagnetic field. The coupling coefficient (κ) between the parts is preferably 0.1 or less. Note that the coupling coefficient (κ) is not limited to this value, and may take various values that improve power transmission. In general, in power transmission using electromagnetic induction, the coupling coefficient (κ) between the power transmission unit and the power reception unit is close to 1.0.

  1 and FIG. 2, the secondary self-resonant coil 340 and the secondary coil 350 correspond to the power receiving unit 110 in FIG. 1, and the primary coil 320 and the primary self-resonant coil 330 transmit power in FIG. Corresponds to the portion 220.

  As described above, in the contactless power transmission and reception system according to the present embodiment, power is transmitted from the power transmission unit to the power reception unit by causing the power transmission unit and the power reception unit to resonate with each other by an electromagnetic field. For example, “magnetic resonance coupling”, “magnetic field (magnetic field) resonance coupling”, “electromagnetic field (electromagnetic field) resonance coupling” or “electric field (electric field) resonance coupling” "

  The “electromagnetic field (electromagnetic field) resonance coupling” means a coupling including any of “magnetic resonance coupling”, “magnetic field (magnetic field) resonance coupling”, and “electric field (electric field) resonance coupling”.

  Since the power transmission unit and the power reception unit described in this specification employ a coil-shaped antenna, the power transmission unit and the power reception unit are mainly coupled by a magnetic field (magnetic field). The part is “magnetic resonance coupling” or “magnetic field (magnetic field) resonance coupling”.

  For example, an antenna such as a meander line can be adopted as the power transmission unit and the power reception unit. In this case, the power transmission unit and the power reception unit are mainly coupled by an electric field (electric field). At this time, the power transmission unit and the power reception unit are “electric field (electric field) resonance coupled”.

The electromagnetic field includes three components of “radiation electromagnetic field”, “induction electromagnetic field”, and “electrostatic magnetic field”.
Among these, there is a region where the intensity of the electromagnetic wave rapidly decreases with the distance from the wave source. In the resonance method, energy (electric power) is transmitted using this near field (evanescent field). That is, by using a near field to resonate a pair of resonators (for example, a pair of LC resonance coils) having the same natural frequency, one resonator (primary self-resonant coil) and the other resonator (two Energy (electric power) is transmitted to the next self-resonant coil. Since this near field does not propagate energy (electric power) far away, the resonance method transmits power with less energy loss than electromagnetic waves that transmit energy (electric power) by "radiation electromagnetic field" that propagates energy far away. be able to.

FIG. 3 is a detailed configuration diagram of the non-contact power transmission / reception system 10 shown in FIG.
Referring to FIG. 3, vehicle 100 includes rectifier 180, charging relay (CHR) 170, power storage device 190, system main relay (SMR) 115, power control, in addition to power receiving unit 110 and communication unit 160. A unit PCU (Power Control Unit) 120, a motor generator 130, a power transmission gear 140, drive wheels 150, a vehicle ECU (Electronic Control Unit) 300 as a control device, a current sensor 171 and a voltage sensor 172 are provided. Including. Power receiving unit 110 includes a secondary self-resonant coil 111, a capacitor 112, and a secondary coil 113.

  Vehicle 100 further includes cooling fans 175 to 177 for cooling power reception unit 110, rectifier 180, and power storage device 190, respectively. Vehicle 100 may further include temperature sensors 181 to 183 for measuring temperatures of power reception unit 110, rectifier 180, and power storage device 190, respectively.

  In this embodiment, an electric vehicle is described as an example of vehicle 100, but the configuration of vehicle 100 is not limited to this as long as the vehicle can travel using electric power stored in the power storage device. Other examples of the vehicle 100 include a hybrid vehicle equipped with an engine and a fuel cell vehicle equipped with a fuel cell.

  Secondary self-resonant coil 111 receives power from primary self-resonant coil 221 included in power transmission device 200 by electromagnetic resonance using an electromagnetic field.

  Regarding the secondary self-resonant coil 111, the primary self-resonant coil 221 and the primary self-resonant coil 221 are based on the distance from the primary self-resonant coil 221 of the power transmission device 200, the resonant frequencies of the primary self-resonant coil 221 and the secondary self-resonant coil 111, and the like. The Q value indicating the resonance intensity with the secondary self-resonant coil 111 is increased (for example, Q> 100), and the coupling coefficient (κ) indicating the degree of coupling is decreased (for example, 0.1 or less). The number of turns and the distance between the coils are appropriately set.

  The capacitor 112 is connected to both ends of the secondary self-resonant coil 111 and forms an LC resonance circuit together with the secondary self-resonant coil 111. The capacity of the capacitor 112 is appropriately set so as to have a predetermined resonance frequency according to the inductance of the secondary self-resonant coil 111. Note that the capacitor 112 may be omitted when a desired resonance frequency can be obtained with the stray capacitance of the secondary self-resonant coil 111 itself.

  The secondary coil 113 is provided coaxially with the secondary self-resonant coil 111 and can be magnetically coupled to the secondary self-resonant coil 111 by electromagnetic induction. The secondary coil 113 takes out the electric power received by the secondary self-resonant coil 111 by electromagnetic induction and outputs it to the rectifier 180.

  Rectifier 180 rectifies the AC power received from secondary coil 113 and outputs the rectified DC power to power storage device 190 via CHR 170. For example, the rectifier 180 may include a diode bridge and a smoothing capacitor (both not shown). As the rectifier 180, it is possible to use a so-called switching regulator that performs rectification using switching control. However, the rectifier 180 may be included in the power receiving unit 110 to prevent malfunction of the switching element due to the generated electromagnetic field. Therefore, it is more preferable to use a static rectifier such as a diode bridge.

  Note that in this embodiment, the DC power rectified by the rectifier 180 is directly output to the power storage device 190. However, when the DC voltage after rectification is different from the charge voltage allowable by the power storage device 190, May be provided with a DC / DC converter (not shown) for voltage conversion between rectifier 180 and power storage device 190.

  A load resistor 173 for position detection and a relay 174 connected in series are connected to the output portion of the rectifier 180. Before the vehicle authentication is completed and full-scale charging is started, weak power is transmitted as a test signal from the power transmission device 200 to the vehicle. At this time, relay 174 is controlled by control signal SE3 from vehicle ECU 300 to be in a conductive state.

  Voltage sensor 172 is provided between a pair of power lines connecting rectifier 180 and power storage device 190. Voltage sensor 172 detects the DC voltage on the secondary side of rectifier 180, that is, the received voltage received from power transmission device 200, and outputs the detected value VC to vehicle ECU 300. The vehicle ECU 300 determines the power reception efficiency based on the voltage VC, and transmits information related to the power reception efficiency to the power transmission device via the communication unit 160.

  Current sensor 171 is provided on a power line connecting rectifier 180 and power storage device 190. Current sensor 171 detects a charging current for power storage device 190 and outputs the detected value IC to vehicle ECU 300.

  CHR 170 is electrically connected to rectifier 180 and power storage device 190. CHR 170 is controlled by a control signal SE2 from vehicle ECU 300, and switches between supply and interruption of power from rectifier 180 to power storage device 190.

  The power storage device 190 is a power storage element configured to be chargeable / dischargeable. The power storage device 190 includes, for example, a secondary battery such as a lithium ion battery, a nickel metal hydride battery, or a lead storage battery, and a power storage element such as an electric double layer capacitor.

  Power storage device 190 is connected to rectifier 180 through CHR 170. The power storage device 190 stores the power received by the power receiving unit 110 and rectified by the rectifier 180. The power storage device 190 is also connected to the PCU 120 via the SMR 115. Power storage device 190 supplies power for generating vehicle driving force to PCU 120. Further, power storage device 190 stores the electric power generated by motor generator 130. The output of power storage device 190 is, for example, about 200V.

  Although not shown, power storage device 190 is provided with a voltage sensor and a current sensor for detecting voltage VB of power storage device 190 and input / output current IB. These detection values are output to vehicle ECU 300. Vehicle ECU 300 calculates the state of charge of power storage device 190 (also referred to as “SOC (State Of Charge)”) based on voltage VB and current IB.

  SMR 115 is inserted in a power line connecting power storage device 190 and PCU 120. SMR 115 is controlled by control signal SE <b> 1 from vehicle ECU 300, and switches between supply and interruption of power between power storage device 190 and PCU 120.

  Although not shown, the PCU 120 includes a converter and an inverter. The converter is controlled by a control signal PWC from vehicle ECU 300 to convert the voltage from power storage device 190. The inverter is controlled by a control signal PWI from vehicle ECU 300 and drives motor generator 130 using electric power converted by the converter.

  Motor generator 130 is an AC rotating electric machine, for example, a permanent magnet type synchronous motor including a rotor in which permanent magnets are embedded.

  The output torque of motor generator 130 is transmitted to drive wheels 150 via power transmission gear 140 to cause vehicle 100 to travel. The motor generator 130 can generate electric power by the rotational force of the drive wheels 150 during the regenerative braking operation of the vehicle 100. Then, the generated power is converted by PCU 120 into charging power for power storage device 190.

  In a hybrid vehicle equipped with an engine (not shown) in addition to motor generator 130, necessary vehicle driving force is generated by operating this engine and motor generator 130 in a coordinated manner. In this case, the power storage device 190 can be charged using the power generated by the rotation of the engine.

  As described above, communication unit 160 is a communication interface for performing wireless communication between vehicle 100 and power transmission device 200. Communication unit 160 outputs battery information INFO including SOC of power storage device 190 from vehicle ECU 300 to power transmission device 200. Communication unit 160 outputs signals STRT and STP instructing start and stop of power transmission from power transmission device 200 to power transmission device 200.

  The vehicle ECU 300 includes a CPU (Central Processing Unit), a storage device, and an input / output buffer, all of which are not shown in FIG. 1, and inputs signals from each sensor and outputs control signals to each device. The vehicle 100 and each device are controlled. Note that these controls are not limited to processing by software, and can be processed by dedicated hardware (electronic circuit).

  When vehicle ECU 300 receives charge start signal TRG by a user operation or the like, vehicle ECU 300 outputs a signal STRT instructing the start of power transmission to power transmission device 200 via communication unit 160 based on the fact that a predetermined condition is satisfied. . In addition, vehicle ECU 300 outputs a signal STP instructing to stop power transmission to power transmission device 200 through communication unit 160 based on the fact that power storage device 190 is fully charged or an operation by the user.

  The power transmission device 200 includes a high frequency power supply device 210 and a power transmission unit 220. In addition to the communication unit 230, the high frequency power supply device 210 further includes a power transmission ECU 240 that is a control device and a power supply unit 250. Power transmission unit 220 includes a primary self-resonant coil 221, a capacitor 222, and a primary coil 223.

  Power supply unit 250 is controlled by control signal MOD from power transmission ECU 240 and converts power received from an AC power supply such as a commercial power supply into high-frequency power. Then, the power supply unit 250 supplies the converted high frequency power to the primary coil 223.

  Note that FIG. 3 does not show a matching unit that performs impedance conversion, but a matching unit may be provided between the power supply unit 250 and the power transmission unit 220 or between the power reception unit 110 and the rectifier 180.

  Primary self-resonant coil 221 transfers power to secondary self-resonant coil 111 included in power receiving unit 110 of vehicle 100 by electromagnetic resonance.

  As for the primary self-resonant coil 221, the primary self-resonant coil 221 and the secondary self-resonant coil 221 are arranged based on the distance from the secondary self-resonant coil 111 of the vehicle 100, the resonance frequency of the primary self-resonant coil 221 and the secondary self-resonant coil 111, and the like. The number of turns and the inter-coil distance are set so that the Q value indicating the resonance strength with the self-resonant coil 111 increases (for example, Q> 100), and κ indicating the coupling degree decreases (for example, 0.1 or less). Set as appropriate.

  The capacitor 222 is connected to both ends of the primary self-resonant coil 221 and forms an LC resonance circuit together with the primary self-resonant coil 221. The capacitance of the capacitor 222 is appropriately set so as to have a predetermined resonance frequency according to the inductance of the primary self-resonant coil 221. Note that the capacitor 222 may be omitted when a desired resonance frequency is obtained with the stray capacitance of the primary self-resonant coil 221 itself.

  The primary coil 223 is provided coaxially with the primary self-resonant coil 221 and can be magnetically coupled to the primary self-resonant coil 221 by electromagnetic induction. The primary coil 223 transmits the high frequency power supplied through the matching unit 260 to the primary self-resonant coil 221 by electromagnetic induction.

  Communication unit 230 is a communication interface for performing wireless communication between power transmission device 200 and vehicle 100 as described above. The communication unit 230 receives battery information INFO transmitted from the communication unit 160 on the vehicle 100 side, signals STRT and STP instructing start and stop of power transmission, and information related to vehicle authentication, and sends these information to the power transmission ECU 240. Output.

  Although not shown in FIG. 1, power transmission ECU 240 includes a CPU, a storage device, and an input / output buffer. The power transmission ECU 240 inputs a signal from each sensor or the like and outputs a control signal to each device. Control each device. Note that these controls are not limited to processing by software, and can be processed by dedicated hardware (electronic circuit).

  The power transmission ECU 240 and the vehicle ECU 300 cooperate with each other via the communication units 160 and 230 to perform control related to power transmission / reception of the power transmission device of the vehicle. When communication is established, it is determined whether the vehicle is compatible with non-contact charging.

  FIG. 4 is a diagram for explaining a state in which a positional shift occurs when the power reception unit 110 and the power transmission unit in FIGS. 1 and 2 are arranged to face each other.

  As shown in FIG. 4, when a positional deviation (positional deviation amount D) occurs, the impedance of each coil changes and the amount of current flowing through the coil increases. When the amount of current increases, the heat generation of the coil itself increases and the power reception efficiency of the coil decreases.

  That is, in the non-contact charging, the power receiving efficiency varies due to a position shift or the like, and the heat generation amount of the coil also varies. For example, when the power receiving efficiency of the power receiving unit 110 decreases with fluctuations in coil heat generation due to misalignment, the power input to the rectifier 180 decreases and the heat generated by the rectifier 180 decreases. In addition, since the power input to the power storage device 190 is also reduced, the heat generation of the power storage device 190 is also reduced.

  In the present embodiment, the cooling capacity of the cooling device of a device (a coil, a rectifier, a battery, a matching unit, etc.) that generates heat during charging is adjusted in consideration of such variation in the amount of heat generated at each part. As an example, the cooling fans 175 to 177 and 270 are shown in FIG. 4 as the cooling device, but other cooling devices such as a water cooling type cooling device may be used.

FIG. 5 is a diagram for explaining the state of each part and the control of the cooling device.
With reference to FIG. 5, a coil part (power receiving part 110), a rectifier part (rectifier 180), and a battery part (power storage device 190) are shown as parts. For each part, the state of electric power and heat generation, and the control, efficiency, and loss of the cooling device (cooling fan) corresponding thereto are shown.

  First, the coil portion will be described. As shown in FIG. 4, when a positional shift occurs as compared with a state where the positions of the power receiving unit 110 and the power transmitting unit 220 are appropriate (state without positional shift), the coil current increases with respect to the power. And it increases in the coil of the power transmission unit 220. As a result, heat generation in the coil portion also increases.

  Therefore, when the positional deviation occurs, the vehicle ECU 300 and the power transmission ECU 240 in FIG. 3 increase the cooling capacity of the cooling fans 175 and 270 provided in the vicinity of the coil portion, as compared with the state without the positional deviation. At this time, assuming that the transmission power P transmitted from the power transmission unit 220 to the power reception unit 110 and the power reception efficiency A when the position is shifted, the loss when transmitting power from the power transmission unit 220 to the power reception unit 110 is (1−A) × P. It is represented by The power reception efficiency A varies according to the amount of positional deviation.

  Next, the rectifier unit will be described. As shown in FIG. 4, when the position of the power reception unit 110 and the power transmission unit 220 is displaced compared to an appropriate state (a state without displacement), loss in the coil unit increases. The power input to the unit decreases. Therefore, heat generation in the rectifier unit is also reduced.

  Therefore, when the positional deviation occurs, the vehicle ECU 300 in FIG. 3 reduces the cooling capacity of the cooling fan 176 provided in the vicinity of the rectifier 180 as compared to the state without the positional deviation. At this time, assuming that the transmission power sent from the power receiving unit 110 to the rectifier 180 is A × P and the efficiency B of the rectifier 180, the loss in the rectifier 180 is represented by A × P × (1-B). The power reception efficiency B is a fixed value that does not change even if the positional deviation amount changes.

  Further, the battery unit will be described. As shown in FIG. 4, when the position of the power reception unit 110 and the power transmission unit 220 is displaced compared to an appropriate state (a state without displacement), loss in the coil unit increases. The power input to the battery unit via the unit decreases. Therefore, heat generation in the battery part is also reduced.

  Therefore, when a positional deviation occurs, vehicle ECU 300 in FIG. 3 reduces the cooling capacity of cooling fan 177 provided in the vicinity of power storage device 190 as compared to a state without positional deviation.

  FIG. 6 is a flowchart for illustrating control executed by the power transmission device and the vehicle.

  3 and 6, when the process is started, first, in step S <b> 1, in power transmission device 200, power transmission ECU 240 uses communication unit 230 to perform communication with the vehicle. In step S <b> 101, in vehicle 100, vehicle ECU 300 executes communication with the power transmission device using communication unit 160. In steps S1 and S101, it is confirmed whether or not communication is established. If communication is established, it is confirmed whether or not each other can cope with non-contact power transmission and reception. The above determination may be performed by at least one of the vehicle ECU 300 and the power transmission ECU 240, and the determination result may be transmitted to the other by communication.

  If it is confirmed in steps S1 and S101 that contactless power transmission / reception is possible, the vehicle ECU 300 requests the power transmission ECU 240 to transmit predetermined power via the communication units 160 and 230 in steps S2 and S102. . The predetermined power may be any power that can confirm the efficiency of power transmission / reception. In response to the request, the power transmission ECU 240 instructs the power supply unit 250 to transmit predetermined power. Then, when the power transmission unit 220 is energized, non-contact power transmission is performed toward the power reception unit 110 of the vehicle.

  Subsequently, in steps S3 and S103, parameters related to power reception efficiency are acquired. This parameter may be obtained, for example, by determining the power reception efficiency itself from the transmitted power and the received power, or may be a parameter that affects the power reception efficiency such as a positional shift amount or reflected power. Also about acquisition of this parameter, what was acquired by either the power transmission side or the power reception side may be transmitted to the other by communication.

  Further, in step S104, vehicle ECU 300 estimates the temperature of power reception unit 110 and devices connected to power reception unit 110 (for example, rectifier 180, power storage device 190, etc.) based on the parameters acquired in step S103. In step S4, power transmission ECU 240 estimates the temperature of power transmission unit 220 based on the parameter acquired in step S3. The estimated temperature can be determined by using a map that has been created by experimentally obtaining the relationship between the parameter and the estimated temperature. This map may reflect ambient temperature and the like.

  In step S105, based on the parameters acquired in step S103, vehicle ECU 300 determines the cooling capacity of the power receiving unit 110 and the cooling device of the devices (for example, rectifier 180, power storage device 190, etc.) connected to power receiving unit 110. decide. In step S5, the power transmission ECU 240 determines the cooling capacity of the cooling device of the power transmission unit 220 based on the parameter acquired in step S3. An example of the cooling capacity of the cooling device is the number of rotations of the cooling fan. The cooling capacity of the cooling device can be determined using a map that has been created by experimentally obtaining a relationship between a parameter and an appropriate cooling capacity (for example, the rotational speed of a fan) in advance. This map may reflect ambient temperature and the like.

  Subsequent to step S105, vehicle ECU 300 determines in step S106 whether or not charging of power storage device 190 has been completed. Judgment of the completion of charging is made based on whether a predetermined state of charge (SOC) has been reached or whether a designated charging end time has come.

  If it is determined in step S106 that charging has not been completed, the processes in and after step S103 are executed again. On the other hand, if it is determined in step S106 that charging has been completed, the process proceeds to step S107.

  In step S <b> 107, vehicle ECU 300 requests power transmission ECU 240 to stop power transmission via communication units 160 and 230.

  In the power transmission device 200, it is determined in step S6 whether or not there is a power transmission stop request after the process in step S5. In step S6, when there is no power transmission stop request, the processing after step S3 is executed again. On the other hand, if there is a power transmission stop request in step S6, power transmission ECU 240 causes power supply unit 250 to stop power transmission in step S7, and the process ends in steps S8 and S108.

  In FIG. 6, it has been described that the temperature is estimated in S <b> 4 and S <b> 104 based on the parameters related to the power reception efficiency. This makes it possible to estimate the temperature without providing a temperature sensor in the coil section or the like. By using a temperature sensor that measures the ambient temperature in combination with temperature estimation from power reception efficiency, it is possible to increase the accuracy of temperature estimation.

  Furthermore, when the temperature sensors 181 to 183 as shown in FIG. 3 are provided, it is possible to determine whether or not an abnormality has occurred by confirming the relationship between the estimated temperature and the actual temperature.

  Note that the processing of the flowchart of FIG. 6 may be modified such that weak power is transmitted at the start of power transmission / reception to confirm power reception efficiency, complete various settings, and then perform full power transmission / reception.

FIG. 7 is a flowchart for explaining an abnormality determination process executed during charging.
With reference to FIGS. 3 and 7, first, in step S201, estimation of the temperature of the electrical device connected to power reception unit 110 is executed based on a parameter related to power reception efficiency. Since this process is the same as step S104 of FIG. 6, description thereof will not be repeated here.

  Subsequently, in step S202, the temperature sensors 181 to 183 measure the temperatures of the power receiving unit 110, the rectifier 180, and the power storage device 190, respectively. In step S203, it is determined whether or not the measured temperature matches the estimated temperature. Specifically, it is determined whether or not the absolute value of the difference between the estimated temperature and the measured temperature is smaller than a determination threshold value.

  In step S203, if | estimated temperature−measured temperature | <threshold value is satisfied, the process proceeds to step S204, and if not, the process proceeds to step S206.

  In step S204, it is determined that the power receiving unit 110, the rectifier 180, and the power storage device 190 are normal at the time of charging, charging is continued, and the process returns to the main routine of the charging process in step S205.

  On the other hand, in step S206, it is determined that any of power reception unit 110, rectifier 180, and power storage device 190 is abnormal during charging, charging is stopped, and the process ends in step S207.

  Even if the estimated temperature is used without providing the temperature sensor 181 on the coil side, and the rectifier 180 or the power storage device 190 compares the estimated value with the value measured by the temperature sensor 182 or 183, the abnormality determination is performed. good. In this way, it is possible to determine normality / abnormality of non-contact charging even if a temperature sensor is not provided in the coil.

  FIG. 8 is a flowchart for explaining an example of control for changing the cooling capacity of the cooling device in accordance with the power reception efficiency. The processing of this flowchart corresponds to the details of the processing executed in S5 and S105 of FIG.

  Referring to FIG. 8, in step S301, it is determined whether the power reception efficiency is less than a predetermined value. The power reception efficiency is estimated based on the parameters acquired in steps S3 and S103 in FIG. If the power reception efficiency is not less than the predetermined value, the process proceeds to step S304, and the cooling capacity of the cooling fan is set to the current status (standard setting value).

  On the other hand, if the power reception efficiency is less than the predetermined value in step S301, it is necessary to cope with the variation in the heat generation amount of each part caused by the positional deviation as shown in FIG. Accordingly, the process proceeds to step S302, and the cooling capacities of the cooling fan 270 and the cooling fan 175 are increased from the standard set value, while in step S303, the cooling capacities of the cooling fan 176 and the cooling fan 177 are set higher than the standard set value. Decrease. Thereby, optimization of the cooling capacity of each part is achieved.

  When the process of step S303 or S304 is completed, control is returned to the main routine in step S305.

  The cooling fan control process of FIG. 8 may be performed by either vehicle ECU 300 or power transmission ECU 240 or may be performed in a shared manner.

  Further, in the flowchart of FIG. 8, the example of the control for increasing or decreasing the cooling capacity of the cooling fan with respect to the standard set value is shown, but the cooling capacity may be changed in more stages corresponding to the power reception efficiency. . For example, a predetermined number of fan rotations corresponding to the power reception efficiency may be stored as a map, and the fan rotation number may be determined with reference to the map.

  As described above, in the present embodiment, the cooling capacity of the cooling device of the entire contactless charging system can be controlled according to the power reception efficiency, so that the temperature adjustment of each device is optimized each time charging is performed. It becomes possible. Further, if the system does not perform abnormality detection as shown in FIG. 7, the number of temperature sensors 181, 182, and 183 may be reduced, so that a low-cost non-contact charging system can be realized.

  Finally, the present embodiment will be summarized with reference to the drawings again. Referring to FIG. 3, vehicle 100 that is a non-contact power receiving device includes power receiving unit 110 configured to be able to receive power in a non-contact manner, and parameters related to power receiving efficiency of power receiving unit 110 (in addition to power receiving efficiency itself). Vehicle ECU 300 that estimates the temperature of the electrical equipment (rectifier 180, power storage device 190, etc.) connected to power reception unit 110 based on the amount of positional deviation or reflected power.

  Preferably, vehicle ECU 300 controls a cooling device (cooling fans 175, 176, 177) for the electric device based on a parameter related to power reception efficiency.

  More preferably, the cooling device includes a cooling fan 175 that cools the power receiving unit, and a cooling fan 177 that cools the power storage device 190 that is charged by the power received by the power receiving unit 110. For example, as shown in the flowchart of FIG. 8, vehicle ECU 300 controls the cooling capacity of cooling fans 175 and 177 in accordance with the power reception efficiency in power reception unit 110.

  More preferably, the power received by power reception unit 110 is rectified by rectifier 180 and supplied to power storage device 190. The cooling device further includes a cooling fan 176 that cools the rectifier 180. Vehicle ECU 300 further controls the cooling capacity of cooling fan 176 according to the power reception efficiency in power reception unit 110.

  More preferably, as shown in the flowchart of FIG. 8, the vehicle ECU 300 has a cooling capacity of the cooling fan 175 when the power receiving efficiency in the power receiving unit 110 is lower than a predetermined value, compared to when the power receiving efficiency is higher than the predetermined value. And the cooling capacity of the cooling fan 176 or 177 is decreased.

  Preferably, the non-contact power receiving apparatus further includes temperature sensors 181, 182, and 183 that estimate or detect the temperature of the electric device. As shown in the flowchart of FIG. 7, the vehicle ECU 300 receives power when the measured values by the temperature sensors 181, 182, and 183 are different from the estimated values estimated based on the parameters related to the power receiving efficiency of the power receiving unit 110. The charging of the power storage device 190 via the unit 110 is stopped.

  The non-contact charging system 10 includes a cooling fan 175 or 177 that cools the power transmission unit 110 or the power reception unit 220, a cooling fan 177 that cools the power storage device 190 that is charged by the power received by the power reception unit 110, and a power reception unit. 110 includes a vehicle ECU 300 and a power transmission ECU 240 that control the cooling capacity of the cooling fan 175 or 177 and the cooling fan 177 according to the power reception efficiency at 110.

  Preferably, the electric power received by power reception unit 110 is rectified by rectifier 180 and supplied to power storage device 190. The non-contact charging system 10 further includes a cooling fan 176 that cools the rectifier 180. Vehicle ECU 300 and power transmission ECU 240 further control the cooling capacity of cooling fan 176 in accordance with the power reception efficiency in power reception unit 110.

  More preferably, vehicle ECU 300 and power transmission ECU 240 have cooling fan 175 when power reception efficiency in power reception unit 110 is lower than a predetermined value, as compared with the case where power reception efficiency is higher than a predetermined value, as shown in the flowchart of FIG. And the cooling capacity of the cooling fans 176 and 177 are decreased.

  Moreover, although the case where the electromagnetic induction coil is included in the power transmission unit and the power reception unit is illustrated in the present embodiment, the present invention does not include the electromagnetic induction coil in one or both of the power transmission unit and the power reception unit. Even if it is a case (when only a self-resonant coil is used), it can be applied.

  Specifically, in the power transmission device 200 of FIG. 3, the power supply unit 250 may be directly connected to the primary self-resonant coil 221 (resonant coil) without providing the primary coil 223 (electromagnetic induction coil). On the vehicle 100 side, the rectifier 180 may be directly connected to the secondary self-resonant coil 111 (resonant coil) without providing the secondary coil 113 (electromagnetic induction coil).

  In the above embodiment, the case of charging is described as an example. However, the present invention can be applied even when the received power is used for purposes other than charging. For example, the same effect can be obtained even when a load such as a vehicle auxiliary machine is driven by the received power.

  Further, in this embodiment, an example in which contactless power feeding is performed using a resonance method has been described in detail. However, the present embodiment can be modified and applied to other methods using the resonance method. As long as the power receiving efficiency from the power transmission device is used for alignment or the like, the present invention can also be applied to other methods of the resonance method (for example, a non-contact power transmission / reception method using electromagnetic induction, microwave, etc.).

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 10 Non-contact power transmission / reception system, 100 Vehicle, 110 Power receiving part, 111,340 Secondary self-resonant coil, 112,222 Capacitor, 113,350 Secondary coil, 130 Motor generator, 140 Power transmission gear, 150 Drive wheel, 160, 230 communication unit, 171 current sensor, 172 voltage sensor, 173 load resistance, 174 relay, 175-177, 270 cooling fan, 180 rectifier, 181-183 temperature sensor, 190 power storage device, 200 power transmission device, 210 high frequency power supply device, 212 Plug, 220 Power transmission unit, 221,330 Primary self-resonant coil, 223,320 Primary coil, 240 Power transmission ECU, 250 Power supply unit, 260 Matching unit, 300 Vehicle ECU, 310 High frequency power supply, 360 Load, PCU Power control unit Door.

Claims (5)

A power receiving unit configured to be able to receive power without contact;
A control device that controls the power receiving unit and a cooling device that cools the power storage device that is charged by the power received by the power receiving unit ;
The cooling device is
A first cooling device for cooling the power receiving unit;
A second cooling device for cooling the power storage device,
The control device increases the cooling capacity of the first cooling device when the power receiving efficiency in the power receiving unit is lower than a predetermined value, as compared with the case where the power receiving efficiency is higher than the predetermined value, and the second cooling Non-contact power receiving device that reduces the cooling capacity of the device. A power receiving unit configured to be able to receive power without contact;
A control device for controlling a cooling device that cools the power receiving unit, a power storage device charged by the power received by the power receiving unit, and a rectifier;
The power received by the power receiving unit is rectified by a rectifier and given to the power storage device,
The cooling device is
A first cooling device for cooling the power receiving unit;
A second cooling device for cooling the power storage device;
A third cooling device for cooling the rectifier,
The control device increases the cooling capacity of the first cooling device when the power receiving efficiency in the power receiving unit is lower than a predetermined value, compared with the case where the power receiving efficiency is higher than the predetermined value, and the second or second A non-contact power receiving device that reduces the cooling capacity of the cooling device. A temperature measuring device for estimating or detecting the temperature of the power storage device ;
The control device stops charging the power storage device via the power receiving unit when a measured value by the temperature measuring device and an estimated value estimated based on a parameter related to power receiving efficiency of the power receiving unit are different The non-contact power receiving device according to claim 1 or 2 . A first cooling device for cooling the power transmission unit or the power reception unit;
A second cooling device for cooling the power storage device charged by the power received by the power receiving unit;
A control device for controlling the cooling capacity of the first and second cooling devices ,
The control device increases the cooling capacity of the first cooling device when the power receiving efficiency in the power receiving unit is lower than a predetermined value, as compared with the case where the power receiving efficiency is higher than the predetermined value, and the second cooling A contactless charging system that reduces the cooling capacity of the device . A first cooling device for cooling the power transmission unit or the power reception unit;
A second cooling device for cooling the power storage device charged by the power received by the power receiving unit;
A third cooling device that rectifies the power received by the power receiving unit and cools the rectifier that is supplied to the power storage device;
A control device for controlling the cooling capacity of the first to third cooling devices,
The control device increases the cooling capacity of the first cooling device when the power receiving efficiency in the power receiving unit is lower than a predetermined value, compared with the case where the power receiving efficiency is higher than the predetermined value, and the second or second A non-contact charging system that reduces the cooling capacity of the cooling device.

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