WO2012090341A1 - Power control device for contactless charging device - Google Patents

Abstract

In the present invention, an electromagnetic field region is formed that transmits power by means of a power supply device (2) and a power reception device (4) that configure a contactless charging device, and a power control device is provided with: a foreign body detection means (14) that detects the electromagnetic field region and whether or not a foreign body is in the vicinity of the electromagnetic field region; and a control unit that determines whether a foreign body is moving towards the electromagnetic field region on the basis of the detection results of the foreign body detection means (14). Also, when it has been determined that there is a foreign body in the vicinity of the electromagnetic field region, the control unit controls the power transmitted from the power supply device (2) to the power reception device (4) before the foreign body enters the electromagnetic field region.

Description

Power control device for non-contact charger

The present invention relates to a non-contact charging device that supplies power to a secondary battery mounted in, for example, an electric propulsion vehicle (electric vehicle or hybrid vehicle) in a non-contact manner, and in particular, power for controlling transmission power from the power feeding device to the power receiving device. The present invention relates to a control device.

As a technique for transmitting power without contact, a technique using a magnetic field, an electric field, a radio wave, and the like has been developed, and such a contactless power transmission technique eliminates the need for an electric wire that connects the power feeding device and the power receiving device. Therefore, it is possible for the user to save the trouble of connection or to worry about electric leakage or electric shock during rainy weather.

By the way, in non-contact power transmission, if a foreign object such as a metal is interposed between the primary coil and the secondary coil during power feeding, an eddy current is generated in the foreign object and heat is generated. Has been proposed that detects the abnormal heat generation of a foreign object and stops power feeding.

In this device, a power transmission unit that supplies an AC signal to the primary coil to the power supply device, a temperature detection element that is disposed in a magnetic force line forming region of the primary coil, and a temperature at a first time detected by the temperature detection element An abnormal temperature rise detection unit that detects an abnormal temperature rise based on a first temperature that is a second temperature that is a temperature at a second time, and a power transmission control unit that controls power transmission of the power transmission unit are provided. When the abnormal temperature rise is detected by the abnormal temperature rise detection unit, the power transmission control unit controls to stop the power transmission from the primary coil (see, for example, Patent Document 1).

In addition, when there is a person or an object, in order to quickly detect the presence and control the power supply state, the power transmission means, the power reception means for receiving the power from the power transmission means, and the power transmission means and the power reception means Transmission efficiency detection means for detecting transmission efficiency, determination means for determining whether the transmission efficiency detected by the transmission efficiency detection means is equal to or higher than a specified value, and transmission when the detected transmission efficiency is less than the specified value There has also been proposed a power supply system including control means for temporarily stopping power transmission by the means and restarting power transmission by the minute power after a specified time.

In this power supply system, the determination means determines whether or not the transmission efficiency after resuming the transmission with the minute power is greater than or equal to the specified value, and when the transmission efficiency is equal to or greater than the specified value, When the transmission efficiency is less than the specified value, the power transmission by the power transmission means is temporarily stopped, and the power transmission by the minute power is resumed after the specified time (see, for example, Patent Document 2).

JP 2009-273260 A JP 2010-119246 A

However, in the case of the power transmission system of Patent Document 1 or 2, since the power supply control is performed when a person or an object exists in the region where the magnetic field lines are formed, the person or the object approaches the electromagnetic field region during the power supply. In some cases, there is a desire to perform power supply control promptly.

The present invention has been made in view of such problems of the prior art, and is for a non-contact charging apparatus that can quickly perform power feeding control when a person or an object approaches an electromagnetic field region during power feeding. An object is to provide a power control apparatus.

In order to achieve the above object, the present invention is a power control device used in a non-contact charging device including a power feeding device that generates a high-frequency electromagnetic field and a power receiving device that extracts power from the electromagnetic field. The electromagnetic field region for transmitting power is formed by the power receiving device, the foreign matter detection means for detecting whether there is a foreign matter in the electromagnetic field region and its vicinity, and whether the foreign matter is directed to the electromagnetic field region based on the detection result of the foreign matter detection means If the controller determines that there is a foreign object in the vicinity of the electromagnetic field region, control of the power transmitted from the power feeding device to the power receiving device before the foreign object enters the electromagnetic field region is provided. Is to do.

According to the present invention, by controlling the transmission power from the power feeding device to the power receiving device before the foreign substance enters the electromagnetic field region, the safety is improved without any person or object being affected by the electromagnetic field.

FIG. 1 is a block diagram of a non-contact charging device provided with a power control device according to the present invention. 2 is a front view of the non-contact charging apparatus of FIG. FIG. 3 shows an electromagnetic field region formed between the ground side coil unit and the vehicle side coil unit constituting the non-contact charging apparatus of FIG. 1, and (a) and (b) are respectively the ground side coil units. Schematic diagram when the coil center and the coil center of the vehicle-side coil unit are coincident with each other when viewed from above FIG. 4 shows an electromagnetic field region formed between the ground side coil unit and the vehicle side coil unit, and (a) and (b) are schematic diagrams when the vehicle body weight is light and heavy, respectively. FIG. 5 shows an electromagnetic field region, a power control range, and a foreign object entry detection range, and (a) and (b) are schematic views when viewed from the rear of the vehicle and from the side of the vehicle, respectively. FIG. 6 is a flowchart showing transmission power control. FIG. 7 is a flowchart showing a process for determining the power control range and the foreign object entry detection range. FIG. 8 is a flowchart showing the foreign object entry processing.

The present invention is a power control device used in a non-contact charging device including a power feeding device that generates a high-frequency electromagnetic field and a power receiving device that extracts power from the electromagnetic field, and transmits power by the power feeding device and the power receiving device. An electromagnetic field region is formed, and a foreign matter detection means for detecting whether or not there is a foreign matter in the electromagnetic field region and its vicinity, and a control unit for determining whether the foreign matter is directed toward the electromagnetic field region based on the detection result of the foreign matter detection means are provided. When the control unit determines that there is a foreign object in the vicinity of the electromagnetic field region, the control unit controls power transmitted from the power feeding device to the power receiving device before the foreign material enters the electromagnetic field region.

This configuration improves safety without affecting people or objects from electromagnetic fields.

Also, a power control range wider than the electromagnetic field region is set, and when a foreign object enters the power control range, the power transmitted from the power feeding device to the power receiving device is controlled.

Furthermore, a foreign object entry detection range wider than the power control range is set, and if it is determined that there is a foreign object in the foreign object entry detection range before the foreign object enters the power control range, the control unit moves the foreign object toward the electromagnetic field region. It is determined whether or not. By making such a determination, it is possible to detect in advance the entry of a foreign object into the power control range, and it is possible to quickly control the transmission power.

The power supply device includes the first coil unit, while the power reception device includes the second coil unit. Based on the positional relationship between the first coil unit and the second coil unit, the electromagnetic field region, the power control range, and It is preferable to determine the foreign matter entry detection range.

Further, when the foreign substance detection means is provided in the power supply box connected to the commercial power supply, the configuration of the power supply apparatus having the power control apparatus is simplified.

Also, it is preferable to arrange the power supply box at a position where the electromagnetic field region can be seen from the foreign matter detection means.

Alternatively, the foreign object detection means can be attached to the first coil unit.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

FIG.1 and FIG.2 is the block diagram and front view of a non-contact charging device provided with the electric power control apparatus which concerns on this invention.
As shown in FIGS. 1 and 2, the non-contact charging device includes a power feeding device 2 installed in a parking space, for example, and a power receiving device 4 mounted on an electric propulsion vehicle, for example.

The power supply device 2 includes a power supply box 8 connected to a commercial power source 6, an inverter unit 10, a ground side coil unit 12, a foreign object detection unit 14, and a control unit (for example, a microcomputer) 16, and includes a foreign object detection unit. 14 and the control unit 16 constitute a power control device 17 according to the present invention. On the other hand, the power receiving device 4 includes a vehicle side coil unit 18, a rectifying unit 20, a load (battery) 22, and a control unit (for example, a microcomputer) 24.

In the power supply device 2, the commercial power source 6 is a 200 V commercial power source that is a low-frequency AC power source, and is connected to the input end of the power source box 8, and the output end of the power source box 8 is connected to the input end of the inverter unit 10. The output end of the unit 10 is connected to the ground side coil unit 12. On the other hand, in the power receiving device 4, the output end of the vehicle side coil unit 18 is connected to the input end of the rectifying unit 20, and the output end of the rectifying unit 20 is connected to the load 22.

Further, the ground side coil unit 12 is laid on the ground, and the power supply box 8 is erected at a position separated from the ground side coil unit 12 by a predetermined distance, for example. On the other hand, the vehicle side coil unit 18 is attached to, for example, a vehicle body bottom (for example, a chassis).

The power feeding device side control unit 16 performs wireless communication with the power receiving device side control unit 24, and the power receiving device side control unit 24 determines a power command value according to the detected residual voltage of the load 22, and determines the determined power command value. It transmits to the electric power feeder side control part 16. The power feeding device side control unit 16 compares the power feeding power detected by the ground side coil unit 12 with the received power command value, and drives the inverter unit 10 so as to obtain the power command value.

During power feeding, the power receiving device side control unit 24 detects the received power and changes the power command value to the power feeding device side control unit 16 so that the load 22 is not overcurrent or overvoltage.

As shown in FIG. 2, when power is supplied from the power supply device 2 to the power reception device 4, the vehicle side coil unit 18 is disposed to face the ground side coil unit 12 by appropriately moving the vehicle, and the power supply device side control is performed. When the unit 16 drives and controls the inverter unit 10, a high-frequency electromagnetic field is formed between the ground side coil unit 12 and the vehicle side coil unit 18. The power receiving device 4 takes out electric power from the high frequency electromagnetic field and charges the load 22 with the taken out electric power.

The foreign matter detection means 14 is for detecting whether or not there is a foreign matter in the electromagnetic field region and the vicinity thereof. As shown in FIG. 2, the foreign matter detection means 14 may be provided in the power supply box 8 and is separated from the power supply box 8. It can also be provided (see the broken line in FIG. 2), details of which will be described later.

Note that the “foreign matter” in the present invention is a moving body that may enter an electromagnetic field region such as a person or an object.

As shown in FIG. 3, the electromagnetic field region is formed between the units 12 and 18 by making the vehicle side coil unit 18 face the ground side coil unit 12. The coil center of the ground side coil unit 12 is not necessarily coincident when viewed from above (see FIG. 3A), and as shown in FIG. In some cases.

Further, even when the coil center of the vehicle-side coil unit 18 and the coil center of the ground-side coil unit 12 coincide with each other when viewed from above, as shown in FIG. The distance between the side coil units 12 is not constant, and the distance varies depending on the number of passengers or the weight of luggage. FIGS. 4A and 4B show a case where the weight of the vehicle body including the occupant and the luggage is light and heavy, respectively.

Therefore, in the present invention, the electromagnetic field region is determined based on the positional relationship between the coil center of the vehicle side coil unit 18 and the coil center of the ground side coil unit 12, and a power control range wider than the electromagnetic field region, and a power control range. By providing a wider foreign matter entry detection range and determining whether or not foreign matter has entered the foreign matter entry detection range or power control range, power supply control is performed before a person or an object enters the electromagnetic field region.

More specifically, a signal indicating the coil center of the vehicle-side coil unit 18 is transmitted from the power-receiving device-side control unit 24 to the power-feeding device-side control unit 16, and the power-feeding device-side control unit 16 that has received this signal The positional relationship (three-dimensional positional relationship between the horizontal direction and the height direction) with the coil center of the unit 12 is recognized. When the power feeding device side control unit 16 recognizes the positional relationship between the coil center of the ground side coil unit 12 and the coil center of the vehicle side coil unit 18, the coil size of the ground side coil unit 12 and the coil size of the vehicle side coil unit 18 are recognized. The electromagnetic field region is set according to

When the electromagnetic field region is determined, the power feeding device side control unit 16 sets the power control range and the foreign object intrusion detection range obtained by adding the first predetermined length and the second predetermined length in the horizontal direction and the height direction of the electromagnetic field region, respectively. Set.

FIG. 5 shows the electromagnetic field region, the power control range, and the foreign object intrusion detection range set in this way. FIG. 5 (a) is a view from the rear of the vehicle, and FIG. 5 (b) is the side view of the vehicle. It shows the case of seeing more.

Next, foreign object detection and transmission power control will be described with reference to the flowcharts of FIGS.

In step S <b> 1 of the flowchart of FIG. 6, the vehicle equipped with the power receiving device 4 stops so that the coil unit 18 faces the ground side coil unit 12, and the power feeding device side control unit 16 starts from the power receiving device side control unit 24. When receiving the power command value, the power supply apparatus side control unit 16 instructs the inverter unit 10 to start power transmission.

In the next step S2, the foreign matter entry detection range and the power control range are confirmed. The foreign matter entry detection range and the power control range confirmation processing will be described with reference to the flowchart of FIG.

In step S <b> 11, as described above, a signal indicating the coil center of the vehicle side coil unit 18 is transmitted from the power receiving device side control unit 24 to the power feeding device side control unit 16, and based on this signal, the power feeding device side control unit 16. Detects the position of the vehicle-side coil unit 18.

In step S12, the power feeding device side control unit 16 recognizes the horizontal displacement of the vehicle side coil unit 18 with respect to the ground side coil unit 12, and in step S13, the height of the vehicle side coil unit 18 with respect to the ground side coil unit 12 is increased. Recognize the position shift in the vertical direction. Further, in step S14, the power feeding device side control unit 16 is shown in FIG. 3 and FIG. 4 based on the horizontal position and height position displacement of the vehicle side coil unit 18 with respect to the recognized ground side coil unit 12 and the coil size. To determine the electromagnetic field region.

When the electromagnetic field region is determined, in step S15, the power supply device side control unit 16 determines the power control range obtained by adding the first predetermined length in the horizontal direction and the height direction of the determined electromagnetic field region as described above. Further, a foreign object intrusion detection range obtained by adding a second predetermined length longer than the first predetermined length in the horizontal direction and the height direction of the electromagnetic field region is determined. In step S16, the foreign object intrusion detection range and the power control range are determined. The confirmation process is terminated.

Thereafter, in step S3, the foreign object detection unit 14 starts the foreign object detection operation, and the detection result of the foreign object detection unit 14 is input to the power supply device side control unit 16. For this reason, the foreign object detection means 14 is a foreign object by imaging a person or an object as a foreign object, an infrared sensor for detecting infrared rays emitted from the foreign object, transmitting an ultrasonic wave toward the foreign object, and measuring the reflected wave. At least one of an ultrasonic sensor that detects a distance and a direction to the object, a radar that transmits an electromagnetic wave toward a foreign object, and detects the distance and direction to the foreign object by measuring the reflected wave.

As shown in FIG. 2, for example, the camera and the infrared sensor are attached to a power supply box 8 through which the electromagnetic field region can be seen from the sensor. The ultrasonic sensor and the radar are, for example, the upper part of the ground side coil unit 12 (broken line in FIG. 2). These foreign object detection means are all arranged at a position where the field of view is not obstructed by a part of the vehicle (for example, a tire).

In the next step S4, power supply from the ground side coil unit 12 to the vehicle side coil unit 18 is started, and the detection result in step S3 is stored in the power feeding device side control unit 16 as an initial value.

In step S5, the power supply apparatus side control unit 16 compares the detection result of the foreign object detection means 14 with the initial value to determine whether or not a foreign object has entered. If it is determined in step S5 that a foreign object has entered, the process proceeds to step S6 in order to grasp the moving direction of the foreign object, and the transmission power is controlled by confirming the moving path of the foreign object from the start of power supply. A foreign substance entry process for canceling is performed.

The flowchart of FIG. 8 shows the foreign object entry processing. First, in step S21, it is determined whether or not the foreign object is in the foreign object entry detection range (whether or not it has entered). In step S22, it is determined whether or not the foreign matter is heading toward the electromagnetic field region. That is, the foreign matter detection means 14 constantly monitors the electromagnetic field region and the situation in the vicinity thereof from the start of power supply. When the foreign matter enters the foreign matter entry detection range, it grasps the direction in which the foreign matter enters. In step S22, it is determined whether or not a foreign object in the foreign object entry detection range is heading toward the electromagnetic field region.

In Step S22, when it is determined that the foreign object is heading toward the electromagnetic field region, the process proceeds to Step S23, and when it is determined that the foreign object is not heading toward the electromagnetic field region, the process returns to Step S21. In step S23, it is determined whether or not the foreign object determined to be in the electromagnetic field region has entered the power control range. If it is determined in step S23 that the foreign object has entered the power control range, the process proceeds to step S24. If it is determined that the foreign object has not entered the power control range, the process returns to step S21.

In step S24, the power feeding device side control unit 16 performs control to reduce the transmission power from the ground side coil unit 12 to the vehicle side coil unit 18 by a predetermined amount (for example, 1/2) or stop power transmission. In step S25, it is determined whether or not the foreign object is in the power control range. If it is determined that the foreign object is in the power control range, the determination in step S25 is repeated. If it is determined that the foreign object is not in the power control range, the transmission power control is canceled in step S26, and then the process returns to step S21.

Note that the foreign object entry processing described above proceeds to step S27 and ends when it is determined in step S21 that the foreign object is not in the foreign object entry detection range.

On the other hand, if it is determined in step S5 that no foreign object has entered, it is determined in step S7 whether or not charging is completed. If charging is not completed, the process returns to step S5 and charging is completed. If it is, the power supply is terminated and the foreign object detection operation is terminated in step S8.

As described above, the power control device for a non-contact charging device according to the present invention performs power feeding control promptly when a person or an object approaches the electromagnetic field region during power feeding from the power feeding device to the power receiving device. For example, it is useful for supplying power to a power receiving device of an electric propulsion vehicle that may be approached by people or objects inadvertently or accidentally.

2 Power supply device 4 Power reception device 6 Commercial power supply 8 Power supply box 10 Inverter unit 12 Ground side coil unit 14 Foreign matter detection means 16 Power supply device side control unit 17 Power control device 18 Vehicle side coil unit 20 Rectification unit 22 Load (battery)
24 Power receiving device side control unit

Claims (7)

A power control device used for a non-contact charging device configured by a power feeding device that generates a high-frequency electromagnetic field and a power receiving device that extracts power from the electromagnetic field,
An electromagnetic field region for transmitting electric power is formed by the power feeding device and the power receiving device, foreign matter detection means for detecting whether or not there is a foreign matter in the electromagnetic field region and its vicinity, and foreign matter is detected based on the detection result of the foreign matter detection means. A control unit is provided for determining whether or not the electromagnetic field region is headed, and when the control unit determines that there is a foreign object in the vicinity of the electromagnetic field region, the power supply is performed before the foreign object enters the electromagnetic field region. A power control apparatus for a non-contact charging apparatus, wherein power transmitted from the apparatus to the power receiving apparatus is controlled. The power control range wider than the electromagnetic field region is set, and when a foreign object enters the power control range, the power transmitted from the power feeding device to the power receiving device is controlled. The electric power control apparatus for contactless charging devices as described. If a foreign object entry detection range wider than the power control range is set, and it is determined that there is a foreign object in the foreign object entry detection range before the foreign object enters the power control range, the control unit causes the foreign object to be in the electromagnetic field. The power control device for a non-contact charging device according to claim 2, wherein it is determined whether or not the vehicle is moving toward a region. While the power feeding device includes a first coil unit, the power receiving device includes a second coil unit, and based on a positional relationship between the first coil unit and the second coil unit, the electromagnetic field region, The power control device for a non-contact charging device according to claim 3, wherein a power control range and the foreign object entry detection range are determined. The power for a non-contact charging device according to any one of claims 1 to 4, wherein the power supply device includes a power supply box connected to a commercial power supply, and the power supply box is provided with the foreign matter detection means. Control device. 6. The power control device for a non-contact charging device according to claim 5, wherein the power supply box is disposed at a position where the electromagnetic field region can be seen from the foreign matter detection means. The power control apparatus for a non-contact charging apparatus according to claim 4, wherein the foreign object detection means is attached to the first coil unit.

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