JP2019054560A - Non-contact charging facility - Google Patents

Abstract

To provide a non-contact charging facility which measures a voltage and a current of a battery at a secondary side and precisely controls a charging current and a charging voltage at a primary side.SOLUTION: A non-contact charging facility comprises a power supply device 13 having a primary coil 12 which receives power supply by a high frequency power source including an inverter 11 and a power reception device 16 which is provided on a carriage movable with respect to the power supply device 13 and has a secondary coil 14 electromagnetically coupling with the primary coil 12 and a resonance coil 15, and transmits charging state of a battery 17 to the power supply device 13 by optical communication to perform constant voltage charge and constant current charge of the battery 17.SELECTED DRAWING: Figure 1

Description

The present invention is used for, for example, a non-contact charging facility (usually 0.5 kW or more of transmission power) that supplies power in a contactless manner to, for example, a transport cart (for example, AGV) or an automobile battery that moves on a factory or a general road. )

For example, a transport cart powered by a battery in a factory or the like needs to be charged regularly, and the transport cart is stopped using a connection cord by stopping the transport cart near a charger placed at a predetermined place. And the charger was connected, and the battery was being charged. However, when charging a battery using a connection cord, it is extremely troublesome to connect the connection cord to an electric power supply source. For example, as shown in Patent Documents 1 to 3, electric power is supplied to the conveyance carriage without contact. Supply is done.

Japanese Patent Laid-Open No. 2005-94862 JP 2006-325350 A WO2006 / 022365 Japanese Patent No. 5707543

However, as described in Patent Documents 1 to 3, when a resonance circuit is incorporated on the primary coil side or the secondary coil side, there is a problem that a large current flows through the resonance circuit and heat is generated.
Therefore, as shown in Patent Document 4, a non-contact power supply apparatus is proposed in which the resonance current of the secondary coil is controlled by using a switching element, and the secondary resonance current is kept constant and heat generation in the secondary circuit is suppressed. Has been.

However, if a current control unit is provided on the secondary side, a device for controlling the current to be constant is required for the transport carriage including all the secondary side devices, which is not economically preferable.
In the device described in Patent Document 4, the primary device may operate regardless of the state of the secondary device, and wasteful power may be consumed.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a non-contact charging facility that measures battery voltage and current on the secondary side and accurately controls charging current and charging voltage on the primary side. And

A non-contact charging facility according to the present invention that meets the above object is provided in a fixed state on a side wall, a floor portion, or a ceiling portion of a structure, and includes a power feeding device having a primary coil that receives power from a high-frequency power source including an inverter, and the power feeding A power receiving device having a secondary coil and a resonance coil that are electromagnetically coupled to the primary coil, and the power feeding device and the power receiving device are arranged laterally during power feeding. In a non-contact charging facility that is arranged with a movable gap and charges a battery connected to the power receiving device from the power feeding device,
1) First and second optical communication units that are connected to the control unit (A) of the power feeding device and the control unit (B) of the power receiving device, respectively, and are arranged to face each other and exchange optical signals;
2) A signal of a charging voltage of the battery measured by the voltage measuring unit, a charging current of the battery measured by the current measuring unit, and an operating temperature of the power receiving device measured by a thermometer provided in the control unit (B) Are respectively converted and sent to the second optical communication unit,
3) Provided in the control unit (A), receives the signal from the first optical communication unit, detects the charging voltage and the charging current, performs PWM control of the inverter that oscillates at a fixed frequency, When the charging voltage is lower than a specified voltage, a constant current control to the battery is performed, and when the charging voltage becomes the specified voltage, a charging control means for performing a constant voltage control to the battery;
4) A first protection provided in the control unit (A), which stops the operation of the inverter when the operating temperature exceeds a predetermined temperature value in response to a signal from the first optical communication unit. Means,
5) provided in the control unit (A), and when the charging current exceeds a maximum current value or when the charging voltage exceeds a maximum voltage value by a signal from the first optical communication unit, A second protective means for stopping the operation of the inverter;
6) A third protection unit is provided in the control unit (A), and stops the operation of the inverter when a predetermined time has elapsed after the constant voltage control to the battery is completed.

In the non-contact charging facility according to the present invention, the optical signal processing means converts data measured by the voltage measuring means, the current measuring means, and the thermometer into digital signals, and the converted digital data is further converted into a serial signal. Is transmitted as an optical signal from the second optical communication unit, the optical signal is received by the first optical communication unit, demodulated by the charge control unit, and the high frequency signal is transmitted by the charge control unit. It is preferable to control the power supply.

In the non-contact charging facility according to the present invention, the power receiving device includes a secondary E core made of a ferrite core, the secondary coil wound around a central magnetic pole portion of the secondary E core, and the resonance coil. A resonance capacitor is connected to the resonance coil, and the power feeding device includes a primary core made of a ferrite core having a plate-like portion and a rod-like portion that protrudes from the center of the plate-like portion, and the rod-like portion. It is preferable to have the primary coil wound around.

The non-contact charging equipment according to the present invention is connected to the control unit (A) of the power feeding device and the control unit (B) of the power receiving device, respectively, and is arranged oppositely to transmit and receive an optical signal. Since the communication unit is included, the light has directivity, and the power feeding device and the power receiving device can be signal-connected with less interference compared to radio waves.
In addition, the control unit (B) converts the signal between the charging voltage and charging current of the battery measured by the voltage measuring unit and the current measuring unit and the operating temperature of the power receiving device measured by the thermometer, The optical signal processing means for sending to the optical communication unit and the PWM of the inverter that is provided in the control unit (A), receives the signal from the first optical communication unit, detects the charging voltage and charging current, and oscillates at a fixed frequency When the control voltage is lower than the specified voltage, the battery has a constant current control, and when the charge voltage reaches the specified voltage, the battery has a charge control means for performing the constant voltage control. The output of the inverter can be controlled while looking at the voltage and current on the secondary side.

Furthermore, the non-contact charging equipment according to the present invention is provided in the control unit (A) and stops the operation of the inverter when the operating temperature exceeds a predetermined temperature value in response to a signal from the first optical communication unit. Therefore, the charging operation can be stopped by sensing the temperature abnormality on the power receiving side.

And the non-contact charging equipment which concerns on this invention is provided in a control part (A), and when a charging current exceeds a maximum current value by the signal from a 1st optical communication part, or a charging voltage is a maximum voltage value Since the second protection means for stopping the operation of the inverter is provided when exceeding the above, it is possible to detect an abnormal state on the power receiving side and protect the power feeding device and the power receiving device.

Moreover, the non-contact charging equipment according to the present invention is provided in the control unit (A), and a third protection means for stopping the operation of the inverter after a certain time has elapsed after the constant voltage control to the battery is completed. Since it is provided, overcharging of the battery can be prevented, and the completion of charging can be notified to the power feeding device, the power receiving device, or the outside. In this case, it is preferable to activate the lamp or buzzer.

In the non-contact charging facility according to the present invention, the optical signal processing means converts the data measured by the voltage measuring means, the current measuring means, and the thermometer into digital signals, and further converts the converted digital data into serial signals. When the optical signal is transmitted from the second optical communication unit, the optical signal is received by the first optical communication unit, demodulated by the charging control means, and the high frequency power source is controlled, the signal processing is simplified, There are few malfunctions.

In the non-contact charging facility according to the present invention, the power receiving device includes a secondary side E core made of a ferrite core and a secondary coil and a resonance coil wound around the central magnetic pole portion of the secondary side E core, A resonance capacitor is connected to the coil, and the power supply device is a ferrite core primary side core having a plate-like portion and a rod-like portion that protrudes from the center of the plate-like portion, and a primary coil wound around the rod-like portion , The magnetic coupling between the primary coil and the secondary coil becomes stronger, and the power transmission efficiency increases. Furthermore, even if the orientation of the secondary E core in the longitudinal direction changes in plan view, power can be supplied with the same transmission efficiency as long as other conditions are the same.

It is a schematic block diagram of the non-contact charging equipment which concerns on one embodiment of this invention. It is explanatory drawing of the non-contact charging equipment. It is explanatory drawing around the secondary coil which looked at the power receiving apparatus of the non-contact charging equipment from the bottom. It is explanatory drawing around the primary coil and secondary coil of the non-contact charging equipment. It is a graph which shows the relationship between the charging current at the time of using the non-contact charging equipment, and time.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
As shown in FIGS. 1 and 2, a non-contact charging facility 10 according to an embodiment of the present invention is provided in a fixed state on a side wall, a floor portion, or a ceiling portion of a structure. A power feeding device 13 having a primary coil 12 to be supplied, and a power receiving device having a secondary coil 14 and a resonance coil 15 which are provided in an automobile or a transport carriage movable relative to the power feeding device 13 and are electromagnetically coupled to the primary coil 12. 16, and during power feeding, the power feeding device 13 and the power receiving device 16 are arranged with a laterally movable gap, and the secondary coil 14 and the resonance coil 15 are arranged immediately above the primary coil 12 of the power feeding device 13. In the state, the battery 17 connected to the power receiving device 16 is charged from the power feeding device 13. Here, the laterally movable gap refers to a space in which the secondary coil 14 and the resonance coil 15 can freely move laterally with respect to the primary coil 12 arranged in a fixed state.

The non-contact charging facility 10 is connected to the control unit (A) 19 of the power feeding device 13 and the control unit (B) 20 of the power receiving device 16, respectively, and is arranged to face each other to exchange optical signals. Second optical communication units 21 and 22 are provided. Here, each of the first and second optical communication units 21 and 22 includes a light emitting unit (for example, an LED) and a light receiving unit (for example, a photodiode) (not shown), and receives an optical signal (A) from the power feeding device 13. An optical signal (B) is sent from the power receiving device 16 to the power supply device 13 to the device 16.

The control unit (B) 20 includes a charging voltage and a charging current of the battery 17 measured by the voltage measuring unit 23 and the current measuring unit 24, and an operating temperature of the power receiving device 16 (particularly, the resonance coil 15) measured by the thermometer 25. And an optical signal processing means 26 for converting the signal to be sent to the second optical communication unit 22.

The control unit (A) 19 receives a signal from the first optical communication unit 21, detects the included charging voltage and charging current signals, performs PWM control of the inverter 11 that oscillates at a fixed frequency, When the charging voltage is lower than the specified voltage (Vc, see FIG. 5), the constant current control to the battery 17 is performed, and when the charging voltage becomes the specified voltage (Vc), the constant voltage control to the battery 17 is performed. Charge control means 28 is provided.

Here, the optical signal processing means 26 converts the data measured by the voltage measuring means 23, the current measuring means 24 and the thermometer 25 from an analog signal to a digital signal, and further converts the converted digital data into a serial signal. The optical signal is transmitted from the second optical communication unit 22, the optical signal is received by the first optical communication unit 21, demodulated by the charge control unit 28, and voltage, current, and temperature signals are received by the charge control unit 28. And the inverter (high frequency power supply) 11 is controlled using the voltage and current.
Here, the power source of the inverter 11 is obtained by converting a commercial power source (for example, three-phase alternating current) 30 into direct current by a rectifier circuit 31.

Further, the control unit (A) 19 receives the signal from the first optical communication unit 21 and operates the inverter 11 via the charge control means 28 when the operating temperature exceeds a predetermined temperature value (Tc). It has the 1st protection means 33 to stop.

Then, in the control unit (A) 19, when the charging current exceeds the maximum current value (Imax) or the charging voltage exceeds the maximum voltage value (Vmax) by the signal from the first optical communication unit 21 In this case, second protection means 34 for stopping the operation of the inverter 11 via the charge control means 28 is provided. When the charging current is less than the minimum current value (Imin), or when the charging voltage is less than the minimum voltage value (Vmin), an alarm can be issued from the charging control means 28.

The control unit (A) 19 is provided with third protection means 35 that stops the operation of the inverter 11 via the charge control means 28 after a certain time has elapsed after the constant voltage control to the battery 17 is completed. ing. This third protection means 35 has a lamp output, and has an electric wave, an ultrasonic wave, a radio signal by light, or a contact signal, and is an automatic transport vehicle that is an example of a transport carriage having the power receiving device 16. (AGV) or the completion of charging of the automobile can be detected and started.

A resonance capacitor 37 is connected to the resonance coil 15, and the output of the secondary coil 15 is connected to a battery 17 as a load via a rectifier 39. 2 is used for experiments, a three-phase AC voltmeter 40 and ammeter 41 on the primary side, and a high-frequency voltmeter 42 that measures the output voltage and output current of the inverter 11, respectively. And a high-frequency ammeter 43.
Further, the power receiving device 16 is provided with a DC voltmeter 44 that measures the charging voltage of the battery 17 and a DC ammeter 45 that measures the charging current of the battery 17.

The operating frequency of the inverter 11 is preferably about 20 to 100 kHz that exceeds the audible frequency, but in this embodiment is fixed to 20 kHz. Since an excessive current flows at the resonance frequency due to the combination of the resonance coil 15 and the capacitor 37, ω ((resonance current) expressed by the following equation is equal to or less than an allowable current used for the resonance coil 15. = 2πf).

I = V / {(R ² + (ωL−1 / ωC) ² } ^0.5
However, R is a circuit resistance, L is the inductance of the resonance coil 15, C is the capacitance of the resonance capacitor, and f is the frequency.
Specifically, it is preferable to actually measure, for example, to set the resonance current to 0.5 to 1 times the charging current of the battery 17. The resonance frequency of the resonance circuit is preferably larger than the oscillation frequency of the inverter 11, but can be reduced.

Next, a specific example of the periphery of the primary coil 12 and the periphery of the secondary coil 14 and the resonance coil 15 used in the non-contact charging facility 10 will be described with reference to FIGS.
As shown in FIG. 4, the primary core 46 around which the primary coil 12 is wound includes a circular or square plane part (plate-like part) 47 with rounded corners, and a circle at the center of the plane part 47. It has a columnar (radius r) upright magnetic pole portion (an example of a rod-like portion) 48 and is made of a ferrite core. The upright magnetic pole portion 48 has a cross-sectional area in which the magnetic flux of the primary coil 12 is not saturated, and the thickness g of the flat portion 47 is 0.5r to r so as not to be magnetically saturated. Note that a litz wire is used for the primary coil 12 and is wound around the upright magnetic pole portion 48 by about 10 to 30 turns. The upright magnetic pole portion 48 and the flat surface portion 47 are preferably integrated with no joint, but may be formed of a divided structure and bonded with an adhesive or the like. In this case, an adhesive containing magnetic powder is preferably used.

A secondary E core 49 using the ferrite core material shown in FIGS. 3 and 4 is used for the power receiving device 16, and the secondary coil 14 and the resonance coil 15 are wound around the central magnetic pole portion 50 of the E core 49. . The resonance coil 15 is wound about 10 to 50 turns, for example, and the secondary coil 14 is about 5 to 20 turns, for example. The cross-sectional area of the E core 49 is also sufficiently large so as not to be magnetically saturated by the current flowing through the secondary coil 14 and the resonance coil 15.

The maximum diameter d of the planar portion 47 of the primary side core 46 is, for example, one time the maximum diameter in plan view of the secondary side core, that is, the E core 49 and the maximum diameter in plan view of the secondary coil 14 and the resonance coil 15. Exceeding 1.6 times and not more than 1.6 times, the magnetic coupling degree between the primary core 46 and the E core 49 is increased, and the leakage magnetic flux escaping to the back side of the primary core 46 is reduced. Further, since the E core 49 is used so as to be covered with the flat portion 47 of the primary side core 46 on the secondary side, the E core 49 and the primary side core 46 are approximately aligned with each other by substantially aligning the E core 49 with the E axis 49. Regardless of the planar orientation of the core 49, efficient non-contact power feeding from the primary side to the secondary side is possible.

Then, operation | movement of this non-contact charging equipment 10 is demonstrated.
As shown in FIGS. 1 and 2, the power feeding device 13 is disposed at a predetermined position, and a transport carriage (for example, AGV) having the power receiving device 16 is disposed at a predetermined position. In this case, the power feeding device 13 is preferably disposed on the ceiling, side wall, or floor of the structure, and the power receiving device 16 is preferably disposed to face the power feeding device 13 with a small gap.
When the sensor detects that the transport carriage has stopped at a predetermined position, the power feeding device 13 and the power receiving device 16 are activated to enter an initial state.

Next, the charging voltage and charging current of the battery 17 are measured by the voltage measuring unit 23 and the current measuring unit 24, and the light from the second optical communication unit 22 is output via the optical signal processing unit 26 together with the output of the thermometer 25. It is emitted to the outside as a signal. The emitted optical signal is received by the first optical communication unit 21 and demodulated into current, voltage, and temperature signals.

As shown in FIG. 5, when the voltage (charge voltage V) detected by the voltage measuring means 23 is lower than the specified voltage (Vc), constant current control (CC region) is performed on the battery 17 to When the voltage reaches the specified voltage, constant voltage control (CV region) is performed on the battery 17. Note that the specified voltage is preferably set to a high range within a little range (for example, 1 to 10%) of the rated voltage (Vs) of the battery 17.
When a predetermined time of about 10 minutes (preferably 1 to 20 minutes) elapses after the completion charging (CV region) is completed, a charging completion signal is sent from the power receiving device 16 to the power feeding device 13 using optical communication, and charging is performed. The work is complete.
In addition, when the charging voltage or charging current to the battery 17 is out of the normal value and is in an abnormal state, the power feeding device 13 is stopped and an alarm (lamp, bell, other signal) is issued. In FIG. 4, reference numeral 51 denotes a cover material that is made of a nonmagnetic material and an insulator and covers the entire primary coil 12.

In the above invention, the ferrite core is used as the magnetic material, but other materials can be used as long as the material has good high frequency characteristics and low iron loss.
Further, the present invention is not limited to the above-described embodiment, and the present invention is also applied to an improvement or a component added to the extent that the gist of the present invention is not changed.

10: Non-contact charging equipment, 11: Inverter, 12: Primary coil, 13: Power feeding device, 14: Secondary coil, 15: Resonant coil, 16: Power receiving device, 17: Battery, 19: Control unit (A), 20 Control unit (B), 21: first optical communication unit, 22: second optical communication unit, 23: voltage measurement unit, 24: current measurement unit, 25: thermometer, 26: optical signal processing unit, 28 : Charging control means, 30: commercial power supply, 31: rectifier circuit, 33: first protection means, 34: second protection means, 35: third protection means, 37: capacitor, 39: rectifier, 40: voltage 41: ammeter, 42: high frequency voltmeter, 43: high frequency ammeter, 44: direct current voltmeter, 45: direct current ammeter, 46: primary core, 47: plane portion, 48: upright magnetic pole portion, 49: E Core, 50: central magnetic pole part, 51: cover material

Claims (3)

Provided in a fixed state on the side wall, floor or ceiling of the structure, and provided in a power supply device having a primary coil that receives power supply from a high-frequency power source including an inverter, and an automobile or a transport carriage movable with respect to the power supply device A power receiving device having a secondary coil and a resonance coil that are electromagnetically coupled to the primary coil, and at the time of power feeding, the power feeding device and the power receiving device are arranged with a laterally movable gap, and the power feeding device In a non-contact charging facility for charging a battery connected to the power receiving device from
1) First and second optical communication units that are connected to the control unit (A) of the power feeding device and the control unit (B) of the power receiving device, respectively, and are arranged to face each other and exchange optical signals;
2) A signal of a charging voltage of the battery measured by the voltage measuring unit, a charging current of the battery measured by the current measuring unit, and an operating temperature of the power receiving device measured by a thermometer provided in the control unit (B) Are respectively converted and sent to the second optical communication unit,
3) Provided in the control unit (A), receives the signal from the first optical communication unit, detects the charging voltage and the charging current, performs PWM control of the inverter that oscillates at a fixed frequency, When the charging voltage is lower than a specified voltage, a constant current control to the battery is performed, and when the charging voltage becomes the specified voltage, a charging control means for performing a constant voltage control to the battery;
4) A first protection provided in the control unit (A), which stops the operation of the inverter when the operating temperature exceeds a predetermined temperature value in response to a signal from the first optical communication unit. Means,
5) provided in the control unit (A), and when the charging current exceeds a maximum current value or when the charging voltage exceeds a maximum voltage value by a signal from the first optical communication unit, A second protective means for stopping the operation of the inverter;
6) A third protection unit is provided in the control unit (A), and after the constant voltage control to the battery is completed, a third protection unit is provided to stop the operation of the inverter after a predetermined time has elapsed. Non-contact charging equipment. 2. The non-contact charging facility according to claim 1, wherein the optical signal processing means converts data measured by the voltage measuring means, the current measuring means, and the thermometer into digital signals, and the converted digital data is further serialized. Converted into a signal, transmitted from the second optical communication unit as an optical signal, received by the first optical communication unit, demodulated by the charge control means, and the charge control means A non-contact charging facility that controls a high-frequency power source. 3. The non-contact charging facility according to claim 1, wherein the power reception device includes a secondary E core made of a ferrite core, the secondary coil wound around a central magnetic pole portion of the secondary E core, and the resonance coil. A resonance capacitor is connected to the resonance coil, and the power feeding device includes a primary core made of a ferrite core having a plate-like portion and a rod-like portion that protrudes from the center of the plate-like portion; A non-contact charging facility comprising the primary coil wound around the rod-shaped portion.

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