JP6746622B2 - Non-contact charging facility - Google Patents

Description

INDUSTRIAL APPLICABILITY The present invention is used, for example, in a contactless charging facility for supplying electric power to a carrier vehicle (for example, AGV) moving in a factory or a general road or a battery of an automobile in a contactless manner (usually used for transmission power of 0.5 kW or more). ) Concerning.

For example, a battery-powered carrier truck in a factory or the like needs to be charged periodically, so stop the carrier truck near a charger placed at a predetermined location and use the connection cord to charge the battery of the carrier truck. And the charger was connected and the battery was being charged. However, when the battery is charged using the connection cord, it is extremely troublesome to connect the connection cord to the power supply source, and therefore, for example, as shown in Patent Documents 1 to 3, the contact cart is supplied with electric power in a non-contact manner. Supply is taking place.

JP 2005-94862 A 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 in the resonance circuit and heat is generated.
Therefore, as disclosed in Patent Document 4, a contactless power supply device is proposed in which the resonance current of the secondary coil is controlled using a switching element to keep the secondary resonance current constant and suppress the heat generation of the secondary circuit. Has been done.

However, if a current control unit is provided on the secondary side, a transport carriage equipped with all the secondary side devices needs a device for controlling the current to be constant, which is economically undesirable.
Further, 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 in some cases.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a non-contact charging facility that measures the voltage and current of a battery on the secondary side and accurately controls the charging current and charging voltage on the primary side. And

The non-contact charging equipment according to the present invention in accordance with the above-mentioned object is provided in a fixed state on a side wall, a floor or a ceiling of a building, and has a primary coil that receives power from a high frequency power source including an inverter, an automobile, or The power feeding device is provided in a carrier, is provided so as to be laterally movable with a gap with respect to the power feeding device, and has a power receiving device having a secondary coil and a resonance coil electromagnetically coupled to the primary coil. In a non-contact charging facility for charging a battery connected to the power receiving device from
1) Second and first optical communications, which are respectively connected to and opposed to the control unit (B) of the power receiving device and the control unit (A) of the power feeding device to exchange optical signals using visible light. Department,
2) A signal of the charging voltage of the battery measured by voltage measuring means, the charging current of the battery measured by current measuring means, and the operating temperature of the resonance coil measured by a thermometer provided in the control unit (B). An optical signal processing means for sending from the second optical communication unit to the first optical communication unit,
3) The control unit (A) is provided, receives the signal from the first optical communication unit, detects the charging voltage and the charging current, and 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 for the battery is performed, and when the charging voltage is the specified voltage, a charge control unit that performs a constant voltage control for the battery,
4) A first protection which is provided in the control unit (A) and stops the operation of the inverter when the operating temperature exceeds a predetermined temperature value upon receiving a signal from the first optical communication unit. Means and
5) When the charging current exceeds a maximum current value or the charging voltage exceeds a maximum voltage value, which is provided in the control unit (A), and the signal from the first optical communication unit, Second protection means for stopping the operation of the inverter;
6) provided in the control unit (A), to verify the completion of the constant voltage control to the battery, and a third protecting means for stopping the operation of the inverter is provided,
The power receiving device has a secondary side E core made of ferrite, the secondary coil wound around a central magnetic pole portion of the secondary side E core, and the resonance coil, and a resonance capacitor is connected to the resonance coil. ,
The power feeding device is wound around the primary magnetic core made of ferrite having a circular flat surface portion in plan view and a column-shaped upright magnetic pole portion formed to project in the center of the flat surface portion, and the upright magnetic pole portion. It has the primary coil, and the diameter of the plane portion is one time the diameter of the largest circle among the circles surrounding the secondary side E core, the secondary coil, and the resonance coil in plan view. Exceeding 1.6 times or less.

The third protection means is: 1) After constant current (charging) control, constant voltage (charging) control is performed until the charging current becomes a predetermined current or less to stop the operation of the inverter. 2) Further, When the operation of the inverter is stopped after a lapse of a certain time after the completion of the constant voltage (charge) control, 3) After the constant current (charge) control, the timer is counted to perform the constant voltage (charge) control, and the timer is operated. There is a case where the operation of the inverter is stopped by counting up.

In the contactless charging equipment 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 a digital signal, and further converts the converted digital data into a serial signal. Converted into the optical signal transmitted from the second optical communication unit as an optical signal, the optical signal is received by the first optical communication unit, demodulated by the charging control unit, and the inverter by the charging control unit. It is preferable to perform the PWM control.

In the non-contact charging facility described above, the first and second wireless communication units that use radio waves or ultrasonic waves as mediums may be used instead of the first and second optical communication units described above. In this case, the above-mentioned optical signal becomes a radio signal using radio waves or ultrasonic waves as a medium, and the optical signal means becomes a radio signal means using radio waves or ultrasonic waves as a medium (that is, to be replaced).

In the non-contact charging facility according to the present invention, the charging voltage and charging current of the battery, which are provided in the control unit (B) and are measured by the voltage measuring unit and the current measuring unit, and the operating temperature of the power receiving device, which is measured by the thermometer, are provided. An optical signal processing unit that converts a signal and sends the signal to the first optical communication unit and a control unit (A) are provided, and receives a signal from the first optical communication unit to detect a charging voltage and a charging current, Performs PWM control of the inverter that oscillates at a fixed frequency, performs constant current control on the battery when the charging voltage is lower than the specified voltage, and performs constant voltage control on the battery when the charging voltage reaches the specified voltage. Since it has a charging control means for performing, the output of the inverter can be controlled while observing the voltage and current on the secondary side.

Further, 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 by receiving a signal from the first optical communication unit. Since the first protection means is provided, it is possible to detect the temperature abnormality on the power receiving side and stop the charging operation.

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 a signal from a 1st optical communication part, or a charging voltage has a maximum voltage value. When it exceeds, the second protection means for stopping the operation of the inverter is provided. Therefore, it is possible to detect the abnormal state on the power receiving side in advance and protect the power feeding device and the power receiving device.

Further, the contactless charging equipment according to the present invention is provided in the control unit (A), and is provided with a third protection means for stopping the operation of the inverter after confirming the completion of the constant voltage control for the battery. Therefore, it is possible to prevent the battery from being overcharged and notify the power supply device, the power reception device, or the outside of the completion of charging. In this case, it is preferable to activate the lamp or buzzer.

In the contactless charging equipment 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. , 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 unit, and PWM control of the inverter is performed, the signal processing is simplified, There are few malfunctions.

In particular, the contactless charging facility 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 opposite to each other to perform the first and second optical communication. Since the communication unit is included, light (including ultraviolet rays, visible rays, infrared rays, and far infrared rays) has directivity, and the power feeding device and the power receiving device can be signal-coupled with less interference compared to radio waves.

In the contactless charging equipment according to the present invention, the power receiving device has a secondary E core made of ferrite, a secondary coil wound around a central magnetic pole portion of the secondary E core, and a resonance coil. A resonance capacitor is connected to the power supply device, and the power feeding device includes a ferrite primary-side core having a circular flat surface portion in plan view and a cylindrical upright magnetic pole portion formed to project in the center of the flat surface portion; Since it has the primary coil wound around the magnetic pole portion, the magnetic coupling between the primary coil and the secondary coil becomes stronger, and the power transmission efficiency increases. Furthermore, even if the longitudinal direction of the secondary side E core in plan view changes, if the other conditions are the same, power can be supplied with the same transmission efficiency.

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

Next, an embodiment of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention.
As shown in FIG. 1 and FIG. 2, a non-contact charging facility 10 according to an embodiment of the present invention is fixedly provided on a side wall, floor or ceiling of a building, and is supplied with power from a high frequency power source including an inverter 11. A power feeding device 13 having a primary coil 12 for receiving the power, and a power receiving device 16 having a secondary coil 14 and a resonance coil 15 which are provided in an automobile or a carriage that can move laterally with respect to the power feeding device 13 and are electromagnetically coupled to the primary coil 12. When power is supplied, the power receiving device 16 is arranged so as to be laterally movable with respect to the power feeding device 13 with a gap, and the secondary coil 14 and the primary coil 12 of the power feeding device 13 are provided directly above (or just below, directly beside) the primary coil 12. With the resonance coil 15 arranged, the battery 17 connected to the power receiving device 16 is charged from the power feeding device 13. Here, the laterally movable gap means a space in which the secondary coil 14 and the resonance coil 15 can freely laterally move with respect to the primary coil 12 arranged in a fixed state.

Then, 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 (one example of a wireless signal). It has the 1st, 2nd optical communication part (an example of a 1st, 2nd wireless communication part) 21 and 22 which performs. Here, each of the first and second optical communication units 21 and 22 has a light emitting unit (for example, LED) and a light receiving unit (for example, photodiode) (not shown), and receives the optical signal (A) from the power feeding device 13. An optical signal (B) is transmitted from the power receiving device 16 to the device 16 to the power feeding device 13.

In the control unit (B) 20, the charging voltage and charging current of the battery 17 measured by the voltage measuring unit 23 and the current measuring unit 24, and the operating temperature of the power receiving device 16 (in particular, the resonance coil 15) measured by the thermometer 25. An optical signal processing unit (an example of a wireless signal processing unit) 26 for converting the signal of and is sent to the second optical communication unit 22 is provided.

The control unit (A) 19 receives the signal from the first optical communication unit 21, detects the contained charging voltage and charging current signals, and 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 for the battery 17 is performed, and when the charging voltage becomes the specified voltage (Vc), the constant voltage control for the battery 17 is performed. Charging control means 28 is provided. Usually, the specified voltage is preferably about 1.1 to 1.15 times the rated voltage of the battery, but the present invention is not limited to this number.

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 into 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 the voltage, current, and temperature signals are generated by the charge control unit 28. Is stored, and the PWM control of the inverter (high frequency power supply) 11 is performed by using this 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 a direct current by a rectifier circuit 31.

Further, the control unit (A) 19 operates the inverter 11 via the charging control unit 28 when the operating temperature exceeds the predetermined temperature value (Tc) in response to the signal from the first optical communication unit 21. It has a first protection means 33 for stopping.

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, the second protection means 34 for stopping the operation of the inverter 11 via the charge control means 28 is provided. If the charging current is less than the minimum current value (Imin), or if the charging voltage is less than the minimum voltage value (Vmin), the charging control means 28 can also issue an alarm.

The control unit (A) 19 stops the operation of the inverter 11 via the charging control means 28 immediately or after a lapse of a certain time (counted by a timer) after confirming the completion of the constant voltage control for the battery 17. A third protection means 35 is provided. The third protection means 35 has a lamp output and also has a radio signal, an ultrasonic wave, a wireless signal by light, or a contact signal, and is an example of a carrier vehicle having the power receiving device 16 and is an automatic carrier. It is possible to detect that (AGV) or the vehicle has completed charging and start the vehicle.

A resonance capacitor 37 is connected to the resonance coil 15, and an output of the secondary coil 15 is connected to a battery 17 which is a load via a rectifier 39. Since the non-contact charging equipment 10 shown in FIG. 2 is for experimental use, a voltmeter 40 and an ammeter 41 for three-phase AC on the primary side, and a high-frequency voltmeter 42 for measuring the output voltage and the output current of the inverter 11, respectively. And a high frequency ammeter 43.
The power receiving device 16 is also provided with a DC voltmeter 44 for measuring the charging voltage of the battery 17 and a DC ammeter 45 for measuring the charging current of the battery 17.

The operating frequency of the inverter 11 is preferably about 20 to 100 kHz, which exceeds the audible frequency, but is fixed to 20 kHz in this embodiment. An excessive current flows at the resonance frequency due to the combination of the resonance coil 15 and the capacitor 37, so that I (resonance current) represented by the following equation becomes ω( = 2πf).

I=V/{(R2 +(ωL-1/ωC)2}0.5
Where R is the 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 the resonance current to be 0.5 to 1 times the charging current of the battery 17, for example. The resonance frequency of the resonance circuit is preferably higher than the oscillation frequency of the inverter 11, but it can also be lower.

Next, specific examples of the surroundings of the primary coil 12 and the surroundings 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. 3 and 4.
In the power feeding device 13, the primary-side core 46 around which the primary coil 12 is wound has, as shown in FIG. 4, a flat surface portion (an example of a plate-shaped portion) 47 having a circular shape or a rounded corner portion, and a flat surface. It has a columnar (radius r) upright magnetic pole portion (an example of a rod-shaped portion) 48 at the center of the portion 47, 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 plane portion 47 is 0.5r to r so that magnetic saturation does not occur. A litz wire is used for the primary coil 12, and is wound around the upright magnetic pole portion 48 for about 10 to 30 turns. The upright magnetic pole portion 48 and the flat surface portion 47 preferably have a seamless integral structure, but may have a divided structure and be joined by an adhesive or the like. In this case, it is preferable to use an adhesive containing magnetic powder as the adhesive.

A secondary side E core 49 using a 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 has, for example, about 10 to 50 turns, and the secondary coil 14 has, for example, about 5 to 20 turns. The cross-sectional area of this E core 49 is also sufficiently large so that it will not be magnetically saturated by the current flowing through the secondary coil 14 and the resonance coil 15.

The maximum diameter d of the plane portion 47 of the primary side core 46 is, for example, 1 times the maximum diameter of the secondary side core, that is, the E core 49 in plan view and the maximum diameter of the secondary coil 14 and the resonance coil 15 in plan view. It is large in the range of more than 1.6 times and less than 1.6 times, increasing the degree of magnetic coupling between the primary side core 46 and the E core 49, and reducing the leakage magnetic flux escaping to the back side of the primary side core 46. Furthermore, since the E core 49 is used on the secondary side so as to be covered with the flat surface portion 47 of the primary side core 46, the axial center of the E core 49 and the axial center of the primary side core 46 are substantially aligned to each other. Regardless of the planar orientation of the core 49, efficient non-contact power feeding from the primary side to the secondary side is possible. In FIG. 4, reference numeral 51 is a cover material which is made of a non-magnetic material and an insulator and covers the entire primary coil 12.

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 arranged at a predetermined position, and a carrier vehicle (eg, AGV) having the power receiving device 16 is arranged at a predetermined position. In this case, the power feeding device 13 is disposed on the ceiling portion, the side wall, or the floor portion of the structure, the power receiving device 16 has a small gap in the power feeding device 13, and the power receiving device 16 moves laterally with respect to the power feeding device 13. It is preferable that they are arranged opposite to each other.
When the sensor detects that the carrier vehicle has stopped at a predetermined position, the power feeding device 13 and the power receiving device 16 are activated to be in the initial state.

Next, the charging voltage and the charging current of the battery 17 are measured by the voltage measuring means 23 and the current measuring means 24, and the output of the thermometer 25 and the light from the second optical communication unit 22 are transmitted via the optical signal processing means 26. It is emitted to the outside as a signal. The emitted optical signal is received by the first optical communication unit 21, and demodulated by the charge control unit 28 into current, voltage, and temperature signals.

As shown in FIG. 5, when the voltage (charging voltage V) detected by the voltage measuring means 23 is lower than the specified voltage (Vc), constant current control (CC region) to the battery 17 is performed to determine the voltage of the battery 17. When the voltage reaches the specified voltage, the constant voltage control (CV region) to the battery 17 is performed. In addition, it is preferable that the specified voltage is set to a range higher than the rated voltage (Vs) of the battery 17 in a range (eg, 5 to 15%).

When a predetermined time of about 10 minutes (preferably 0 to 20 minutes) elapses after completion of the finish charging (CV area), a signal indicating completion of charging is sent from the power receiving device 16 to the power feeding device 13 using optical communication to perform charging. The work is completed. Note that, here, after performing the constant current control, the timer may be operated (that is, by the timer control) to perform the constant voltage (charging) control to complete the charging control.
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 supply device 13 is stopped and an alarm (lamp, bell, other signal) is issued.

In the above invention, the ferrite core is used as the magnetic material, but other materials can be used as long as they have good high frequency characteristics and little iron loss.
Further, the present invention is not limited to the above-described embodiments, and the present invention can be applied to an improvement to the extent that the gist of the present invention is not changed or a case where a component is added. For example, in the above-described embodiment, light is used as the signal medium means, but radio waves or ultrasonic waves are also applicable.

The non-contact charging equipment according to the present invention detects the voltage, current, and temperature states on the power receiving side and wirelessly transmits them to the power feeding side, and controls the voltage and current on the power receiving side. It can be simplified and reduced in weight, resulting in energy savings.

10: Non-contact charging equipment, 11: Inverter, 12: Primary coil, 13: Power supply device, 14: Secondary coil, 15: Resonance coil, 16: Power receiving device, 17: Battery, 19: Control part (A), 20 : Control part (B), 21: first optical communication part, 22: second optical communication part, 23: voltage measuring means, 24: current measuring means, 25: thermometer, 26: optical signal processing means, 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 side core, 47: flat surface portion, 48: upright magnetic pole portion, 49: E Core, 50: Central magnetic pole part, 51: Cover material

Claims (2)

Provided in a fixed state on the side wall, floor or ceiling of the structure, and a power feeding device having a primary coil that receives power from a high frequency power source including an inverter, and a car or a carriage provided with a gap with respect to the power feeding device. And a power receiving device having a secondary coil electromagnetically coupled to the primary coil and a resonant coil, the non-contact charging a battery connected to the power receiving device from the power feeding device. In charging equipment,
1) Second and first optical communications, which are respectively connected to and opposed to the control unit (B) of the power receiving device and the control unit (A) of the power feeding device to exchange optical signals using visible light. Department,
2) A signal of the charging voltage of the battery measured by voltage measuring means, the charging current of the battery measured by current measuring means, and the operating temperature of the resonance coil measured by a thermometer provided in the control unit (B). An optical signal processing means for sending from the second optical communication unit to the first optical communication unit,
3) The control unit (A) is provided, receives the signal from the first optical communication unit, detects the charging voltage and the charging current, and 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 for the battery is performed, and when the charging voltage is the specified voltage, a charge control unit that performs a constant voltage control for the battery,
4) A first protection that is provided in the control unit (A) and that 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 and
5) When the charging current exceeds a maximum current value or the charging voltage exceeds a maximum voltage value, which is provided in the control unit (A), and the signal from the first optical communication unit, Second protection means for stopping the operation of the inverter;
6) provided in the control unit (A), to verify the completion of the constant voltage control to the battery, and a third protecting means for stopping the operation of the inverter is provided,
The power receiving device has a secondary side E core made of ferrite, the secondary coil wound around a central magnetic pole portion of the secondary side E core, and the resonance coil, and a resonance capacitor is connected to the resonance coil. ,
The power feeding device is wound around the primary magnetic core made of ferrite having a circular flat surface portion in plan view and a column-shaped upright magnetic pole portion formed to project in the center of the flat surface portion, and the upright magnetic pole portion. It has the primary coil, and the diameter of the plane portion is one time the diameter of the largest circle among the circles surrounding the secondary side E core, the secondary coil, and the resonance coil in plan view. A non-contact charging facility that is in the range of over 1.6 times . The non-contact charging equipment according to claim 1 , wherein the optical signal processing means converts the data measured by the voltage measuring means, the current measuring means, and the thermometer into a digital signal, and the converted digital data is further serialized. The signal is converted into a signal and 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 charging control unit, and then the charging control unit is operated by the charging control unit. A contactless charging facility characterized by performing PWM control of an inverter.

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