JP7379099B2 - Wireless power supply system, wireless power supply system control method, and its program - Google Patents

Description

The present invention relates to a wireless power supply system, a method of controlling the wireless power supply system, and a program thereof.

BACKGROUND ART Mobile vehicle power supply systems that can suppress a decrease in power supply efficiency have been known. For example, Patent Document 1 discloses a mobile vehicle power supply system that performs contactless power supply to a mobile vehicle located within a power supply area, in which a power receiving coil provided on the mobile vehicle and a power receiving coil arranged at mutually different positions within the power supply area are provided. Based on the detection results of the position detection means, which detects the position of the power reception coil within the power supply area, the position corresponding to the power reception coil among the plurality of power supply coils, etc. A control device is described that includes a control means for selecting a power feeding coil disposed in a power feeding coil and causing contactless power feeding to be performed from the selected power feeding coil. This mobile vehicle power supply system prepares multiple power supply means within the power supply area, detects the position of the power receiving means installed on the moving vehicle within the power supply area, and selects the most suitable one for contactless power supply among the multiple power supply means. By selecting a power feeding means disposed at a certain position to supply power, it is possible to suppress a decrease in power supply efficiency.

JP2013-66291A

However, in the mobile vehicle power supply system described in Patent Document 1, even if it is possible to prevent a decrease in power supply efficiency for electric power by selecting the optimal power supply means from a plurality of power supply means, the most suitable power supply means is selected. This poses a problem in that the power supply efficiency per hour decreases. In addition, since the power feeding device that performs power feeding is selected by performing wireless communication with the power feeding device, electric power is required for the wireless communication, and there is a problem that the power feeding efficiency decreases.

The present invention has been made in view of such problems, and its main purpose is to provide a wireless power supply system with high power supply speed, low power consumption, and high power supply efficiency. Another object of the present invention is to provide a method for controlling a wireless power supply system with high power supply efficiency.

The present invention employs the following means to achieve at least one of the above objects.

The wireless power supply system of the present invention includes:
a power transmission device having a power transmission coil;
a power receiving device having a power receiving coil;
Measuring means for measuring a change in mutual inductance of the power receiving coil that occurs as the power receiving coil moves;
A control means for controlling power transmission of the power transmission device;
Equipped with
The power receiving device is movably provided at a position facing the plurality of power transmitting devices arranged in succession,
The control means controls power transmission from the power transmission device based on the change in the mutual inductance,
It is something.

This wireless power transfer system consists of multiple power transmitting devices arranged in series, a power receiving device movably provided in a position facing the multiple power transmitting devices, and changes in mutual inductance that occur as the power receiving coil moves. The power transmitting apparatus includes a measuring means for measuring and a control means for controlling power transmission by the power transmitting apparatus, and controls power transmission from the power transmitting apparatus based on a change in mutual inductance measured by the measuring means. When the power receiving device moves, the shape of the power receiving coil does not change, so changes in mutual inductance represent changes in the relative positional relationship between the power receiving device and the power transmitting device, so it is necessary to measure changes in mutual inductance. In this way, power transmission from the power transmitting device can be controlled according to the position of the power receiving device. Therefore, by transmitting power when the power receiving device is within a certain range from the power transmitting device, high power transmission efficiency can be obtained. Additionally, by not transmitting power to a power transmitting device that is not located in a position facing the power receiving device, the generation of unnecessary electromagnetic waves can be suppressed. Exposure can be controlled. Furthermore, compared to the case where power is transmitted from all power transmission devices, power consumption can be reduced and power transmission efficiency can be increased. At the same time, by transmitting power from a power transmitting device located near the power receiving device, the total amount of power transmitted to the power receiving device can be increased compared to, for example, transmitting power from any one power transmitting device, resulting in faster and higher power transmission. Gain efficiency.

In the wireless power supply system of the present invention, the control means starts power transmission from the power transmission device when the amount of change in the mutual inductance is equal to or greater than a predetermined start threshold, and The power transmission device may be characterized in that power transmission from the power transmission device is stopped when the power transmission device is equal to or less than a stop threshold. Changes in mutual inductance become larger as the relative positions of the power transmitting coil and the power receiving coil approach Power will be transmitted if the location is within a certain range from By doing so, power is transmitted only when the distance between the power receiving device and the power transmitting device is short, so that high power transmission efficiency can be obtained. On the other hand, by stopping power transmission when the amount of change in mutual inductance is less than a predetermined stop threshold, if the distance between the power receiving device and the power transmitting device is long, power transmission will be stopped. By stopping power transmission when the power transmission efficiency to the power receiving device is low, high power transmission efficiency can be obtained. Note that the "start threshold" and "stop threshold" herein mean predetermined values.

In the wireless power supply system of the present invention, the measuring means is a measuring means for measuring the change in the mutual inductance of each of the power transmitting devices, and the control means is configured to measure the change in the mutual inductance of the adjacent power transmitting devices in advance. The power transmission device may start or stop power transmission when the power is within a predetermined same value range. If the amount of change in mutual inductance of each adjacent power transmitting device is the same (same value range), it is assumed that the relative positions of the power receiving device and the two adjacent power transmitting devices are similar. By starting or stopping power transmission from the power transmitting device when the amount of change in mutual inductance is in the same value range, it is possible to start or stop power transmission from the power transmitting device when the power receiving device is located at an intermediate position between two adjacent power transmitting devices. It will stop. Therefore, by starting or stopping power transmission when the power receiving device is located between the power transmitting device and the adjacent power transmitting device, compared to the case where power is always transmitted from either one power transmitting device or both power transmitting devices, High power transmission efficiency can be obtained. Note that the term "same value range" here means a predetermined value and a value in the vicinity of this value.

In the wireless power supply system of the present invention, the power receiving device moves along a rail provided in a position parallel to the plurality of power receiving coils, and when the power receiving device moves, the center of the power receiving coil is aligned with the power transmitting coil. It may be characterized by passing directly over the center of By doing this, when the power receiving device moves along the rail, the center of the power receiving coil will pass directly above the center of the power transmitting coil, so the power receiving coil will pass through the position with the highest power transmission efficiency. Therefore, high power transmission efficiency can be obtained.

In the wireless power feeding system of the present invention, the length of the outer diameter of the power transmitting coil may be 1.0 times or more and 1.5 times or less the length of the outer diameter of the power receiving coil. By doing this, the power receiving coil is always located at a position facing one or two adjacent power transmitting coils, so by controlling the power transmission from the two adjacent power transmitting coils, power transmission to the power receiving coil can be controlled. can be controlled. Additionally, since it is not necessary to control the power transmission of three or more power transmitting coils, the effort required to control the power transmitting coils can be reduced.

The wireless power supply system control method of the present invention includes:
A power transmitting device having a power transmitting coil, a power receiving device having a power receiving coil, a measuring means for measuring a change in mutual inductance of the power receiving coil that occurs as the power receiving coil moves, and a control means for controlling power transmission of the power transmitting device. A control method for controlling a wireless power feeding system in which the power receiving device is movably provided in a position facing a plurality of power transmitting devices arranged in succession,
a power transmission step of controlling power transmission from the power transmission device based on the change in the mutual inductance;
characterized by comprising;
It is something.

This wireless power transfer system consists of multiple power transmitting devices arranged in series, a power receiving device movably provided in a position facing the multiple power transmitting devices, and changes in mutual inductance that occur as the power receiving coil moves. The power transmitting apparatus includes a measuring means for measuring and a control means for controlling power transmission by the power transmitting apparatus, and controls power transmission from the power transmitting apparatus based on a change in mutual inductance measured by the measuring means. When the power receiving device moves, the shape of the power receiving coil does not change, so changes in mutual inductance represent changes in the relative positional relationship between the power receiving device and the power transmitting device, so it is necessary to measure changes in mutual inductance. In this way, power transmission from the power transmitting device can be controlled according to the position of the power receiving device. Therefore, by transmitting power when the power receiving device is within a certain range from the power transmitting device, high power transmission efficiency can be obtained. Additionally, by not transmitting power to a power transmitting device that is not located in a position facing the power receiving device, the generation of unnecessary electromagnetic waves can be suppressed. Exposure can be controlled. Furthermore, compared to the case where power is transmitted from all power transmission devices, power consumption can be reduced and power transmission efficiency can be increased. At the same time, by transmitting power from a power transmitting device located near the power receiving device, the total amount of power transmitted to the power receiving device can be increased compared to, for example, transmitting power from any one power transmitting device, resulting in faster and higher power transmission. Gain efficiency.

The program of the present invention is a program for causing one or more computers to execute each step of a method for controlling a wireless power supply system. This program may be recorded on a computer-readable storage medium (for example, hard disk, ROM, CD, DVD, flash memory, etc.), or may be recorded on a transmission medium (communication network such as the Internet or wired/wireless LAN). The information may be sent from one computer to another via a computer, or may be exchanged in any other form. Further, even if the program is executed by a device that executes each step of the wireless power supply system control method, the device on which the program is executed and the device on which the process is performed may be different. In either case, if this program is executed by one computer or each step is divided and executed by multiple computers, the same effect as the wireless power supply system control method described above can be obtained. can.

FIG. 1 is a perspective view schematically showing the configuration of a wireless power feeding system 20. As shown in FIG. FIG. 2 is a block diagram for explaining electrical connections of the wireless power supply system 20. FIG. 3 is a flowchart illustrating an example of a power transmission control processing routine.

Next, the wireless power supply system 20 will be described in detail as an example of an embodiment of the present invention. The embodiments and drawings described below illustrate some of the embodiments of the present invention, and are not used for the purpose of limiting the configurations to these, and may be used within the scope of the gist of the present invention. It can be changed as appropriate. Note that in each figure, corresponding components are given the same or similar symbols. Furthermore, in the following description, as shown in FIG. 1, the directions in which the power receiving device 30 moves are referred to as one side direction and the other side direction. Moreover, by showing an example of a method of controlling the wireless power supply system 20, an example of a method of controlling the wireless power supply system of the present invention and an example of its program will also be clarified.

As shown in FIG. 1, a wireless power supply system 20 that is an example of an embodiment of the present invention includes a power receiving device 30 that is movably provided along a rail 22, and a power receiving device 30 that is provided continuously at a position facing the rail 22. A measurement sensor 44 (measurement sensor 44) that measures changes in mutual inductance due to movement of a plurality of power transmitting devices 40 (power transmitting device 40a, power transmitting device 40b, power transmitting device 40c, and power transmitting device 40d) and the power receiving device 30 in each power transmitting device The sensor 44a, the measurement sensor 44b, the measurement sensor 44c, and the measurement sensor 44d, which correspond to the measurement means of the present invention, see FIG. 2), and a control unit 50 (see FIG. 2) that controls power transmission of the plurality of power transmission devices 40. We are prepared. This wireless power feeding system 20 transmits power from a power transmitting device 40 to a power receiving device 30 moving along a rail 22, and wirelessly feeds power to the power receiving device 30. At this time, power transmission from the power transmitting device 40 is controlled based on the amount of change in mutual inductance due to movement of the power receiving device 30, which is measured by the measurement sensor 44. Changes in mutual inductance vary depending on the distance between the power transmitting coil 42 provided in the power transmitting device 40 and the power receiving coil 32 provided in the power receiving device 30. By controlling power transmission, power transmission can be controlled according to the distance between the power transmitting coil 42 and the power receiving coil 32, so power transmission efficiency can be improved.

Specifically, when the shape of the power receiving coil 32 does not change, the amount of change in mutual inductance increases as the relative distance between the power transmitting coil 42 and the power receiving coil 32 approaches, so that the amount of change in mutual inductance remains at a constant value. The above case means that the power receiving device 30 is located within a certain range from the power transmitting device 40. Therefore, by controlling power transmission based on the amount of change in mutual inductance, power transmission can be controlled based on the distance between power transmitting device 40 and power receiving device 30, so power transmission efficiency can be improved.

Furthermore, when the wireless power supply system 20 is functioning normally, the mutual inductance changes only due to the movement of the power receiving device 30, so that the change in mutual inductance that does not depend on the movement of the power receiving device 30 is measured by the measurement sensor 44. If so, it means that some kind of abnormality has occurred. Therefore, by estimating the movement of the power receiving device 30 based on the change in mutual inductance, it is also possible to determine whether there is an abnormality in the wireless power supply system 20.

The power receiving device 30 is a box-shaped device with a power receiving coil 32 provided in the center, and when the power receiving device 30 moves along the rail 22, the center of the power receiving coil 32 passes directly above the center of the power transmitting coil 42. This position is movable along the rail 22 by driving of rollers (not shown). By doing so, when the power receiving device 30 moves along the rail 22, the center of the power receiving coil 32 passes directly above the center of the power transmitting coil 42, so that the power is transferred from the power transmitting coil 42 to the power receiving coil 32. It is possible to increase the efficiency of power transmission.

As shown in FIG. 1, the power transmission device 40 is a box-shaped device in which a power transmission coil 42 is provided in the center, and a plurality of power transmission devices 40 are continuously provided from one side to the other side. There is. At this time, the centers of the power transmission coils 42 provided in the plurality of power transmission devices 40 are arranged in a straight line from one side to the other side, and this imaginary line and the rail 22 are in a mutually parallel positional relationship. By doing this, when the power receiving device 30 moves along the rail 22, the distance between the power transmitting coil 42 and the power receiving coil 32 is kept constant, so when power is transmitted from the power transmitting device 40, the amount of power transmitted is stabilized. can be done. Further, the plurality of power transmission devices 40 are each electrically connected to a control unit 50, and power transmission is controlled based on a control signal from the control unit 50.

Further, at this time, the outer diameter of the power transmitting coil 42 is longer than the outer diameter of the power receiving coil 32. By doing so, power transmission efficiency can be improved when power is transmitted to the power receiving coil 32 that moves as the power receiving device 30 moves. Specifically, the outer diameter of the power transmitting coil 42 is preferably 1.0 to 1.5 times longer than the outer diameter of the power receiving coil 32. By doing this, high power transmission efficiency can be obtained.

The measurement sensor 44 corresponds to the measurement means of the present invention, and is a known ammeter, voltmeter, or circuit that measures the amount of change in mutual inductance. This measurement sensor 44 is provided in each power transmission device 40, as shown in FIG. 2, and is electrically connected to a control unit 50. This measurement sensor 44 measures the change in mutual inductance when the power receiving device 30 moves, and transmits the measured value to the control unit 50. Since the amount of change in mutual inductance changes depending on the positional relationship between power transmitting device 40 and power receiving device 30, the position of power receiving device 30 can be estimated from the amount of change in mutual inductance.

As shown in FIG. 2, the control unit 50 is configured as a microprocessor centered on a CPU 51, and includes a ROM 52 that stores various control programs for controlling power transmission from the power transmission device 40, and a ROM 52 that stores various control programs and the like for controlling power transmission from the power transmission device 40. The RAM 53 that temporarily stores the value of the amount of change in mutual inductance, etc., the storage means 54 that stores various information, and the measurement sensor 44, the power receiving device 30, the power transmission device 40, the storage means 54, etc. Interfaces 55 (hereinafter referred to as "I/Fs 55") that transmit and receive signals are electrically connected via buses 56, respectively. This control unit 50 corresponds to the control means of the present invention, and controls power transmission by the power transmission device 40.

Next, a power transmission control method when transmitting power from the power transmission device 40 will be described using a power transmission control processing routine executed by the control unit 50 as an example. This power transmission control processing routine is repeatedly executed for each power transmission device 40 when power is supplied to the wireless power supply system 20 and the amount of change in mutual inductance measured by the measurement sensor 44 is input as an input value. Therefore, here, the processing performed by the power transmission device 40a will be described as an example. Note that FIG. 3 is a flowchart showing an example of a power transmission control processing routine.

When the power transmission control processing routine stored in the ROM 52 is read out and executed by the CPU 51, the CPU 51 determines whether the input value transmitted from the measurement sensor 44a is greater than or equal to the start threshold value stored in advance in the storage means 54. If it is determined that it is equal to or greater than the start threshold (step S110), power transmission by the power transmission device 40a is started (step S120), and this routine ends. By doing so, when the input value transmitted from the measurement sensor 44a is greater than or equal to a predetermined threshold, that is, when the power receiving device 30 is located within a certain distance from the power transmitting device 40a, power is transmitted from the power transmitting device 40a. be able to. By doing so, power transmission can be started after the power receiving device 30 approaches, so power transmission efficiency can be improved compared to a case where the power transmitting device 40a is always transmitting power.

On the other hand, if the CPU 51 determines in step S110 that the input value is less than the start threshold, it determines whether the input threshold is less than or equal to the stop threshold (step S130), and determines that it is greater than the stop threshold. If so, this routine ends. In such a case, power is being efficiently transmitted from the power transmitting device 40a to the power receiving device 30, so power transmission is continued.

On the other hand, if it is determined in step S130 that the input value is less than or equal to the stop threshold, power transmission to the power transmission device 40 is stopped (step S140), and this routine ends. In such a case, since the power transmitting device 40a and the power receiving device 30 are too far apart, by stopping the power transmission from the power transmitting device 40a, it is possible to stop the low-efficiency power transmission and increase the overall power transmission efficiency. . Note that in such a case, the power receiving device 30 will be located near the power transmitting device 40b adjacent to the power transmitting device 40a, and therefore power will be transmitted from the power transmitting device 40b.

According to the embodiment described in detail above, when the power receiving device 30 moves along the rail 22 provided at a position facing the power transmitting device 40, power is transmitted based on the amount of change in mutual inductance measured by the measurement sensor 44. Controls power transmission of the device 40. At this time, since the amount of change in mutual inductance is determined depending on the distance between the power transmitting coil 42 and the power receiving coil 32, by controlling power transmission based on the amount of change in mutual inductance, the distance between the power transmitting device 40 and the power receiving device 30 can be changed. By transmitting power from the power transmitting device 40 located near the power receiving device 30 among the plurality of power transmitting devices 40, power transmission efficiency can be increased.

Moreover, by transmitting power from the power transmission device 40 when it is determined that the value of the induced electromotive force by the power reception device 30 from among the plurality of power transmission devices 40 is equal to or higher than the start threshold and is determined to be larger than the stop threshold, Since power transmission can be started when the power receiving device 30 is within a certain range from one of the plurality of power transmitting devices 40, it is no longer necessary to transmit power over a long distance to the power receiving device 30, which improves power transmission efficiency. can be increased.

Furthermore, when the power transmitting device 40 moves along the rails 22, the center of the power receiving coil 32 passes directly above the centers of the plurality of power transmitting coils 42, so the center positions of the power transmitting coil 42 and the center positions of the power receiving coil 32 are not directly above each other. Higher power transmission efficiency can be obtained compared to the conventional case.

Furthermore, since the length of the outer diameter of the power transmitting coil 42 is formed to be 1.0 times or more and 1.5 times or less than the length of the outer diameter of the power receiving coil 32, the length of the outer diameter of the power transmitting coil 42 is High power transmission efficiency can be obtained compared to the case where the outer diameter of the power receiving coil 32 is longer than the length.

It goes without saying that the present invention is not limited to the embodiments described above, and can be implemented in various forms as long as they fall within the technical scope of the present invention.

For example, in the embodiment described above, when the input value in each power transmitting device 40 is equal to or higher than the start threshold, the power transmission of the power transmitting device 40 is started, and when the input value is equal to or lower than the stop threshold, the power transmission is stopped. The values of the induced electromotive force in the power transmitting device 40 (for example, the power transmitting device 40a and the power transmitting device 40b) may be compared, and if the values are within a predetermined same value range, power transmission may be started or stopped. In this way, when the values of the induced electromotive force in the adjacent power transmitting devices 40 (power transmitting coils 42) are located in the same value range, the power receiving device 30 is located at approximately the same distance from both of the adjacent power transmitting devices 40. Therefore, high power transmission efficiency can be obtained by the power receiving device 30 starting or stopping power transmission when the values of the induced electromotive force are in the same value range.

In the embodiment described above, each power transmission device 40 is provided with a measurement sensor 44, but the measurement sensor 44 is not limited to this shape as long as it can measure a plurality of induced electromotive forces. may be one. Furthermore, the measurement sensor 44 measures the induced electromotive force of each power transmission coil 42 sequentially, and does not necessarily have to measure the induced electromotive force of all the power transmission coils 42 at the same time. In either case, the same effects as in the embodiment described above can be obtained.

In the embodiment described above, the power transmitting device 40 includes the power transmitting device 40a, the power transmitting device 40b, the power transmitting device 40c, and the power transmitting device 40d, but the number of the power transmitting devices 40 is not limited to this. Any above is fine. By doing so, effects similar to those of the embodiment described above can be obtained.

As shown in the embodiments described above, the present invention can be used in the field of wireless power supply, particularly as a means for wirelessly supplying power to a moving power receiving circuit.

20... Wireless power supply system, 22... Rail, 30... Power receiving device, 32... Power receiving coil, 40... Power transmitting device, 40a... Power transmitting device, 40b... Power transmitting device, 40c... Power transmitting device, 40d... Power transmitting device, 42... Power transmitting coil, 44... Measurement sensor, 44a... Measurement sensor, 44b... Measurement sensor, 44c... Measurement sensor, 44d... Measurement sensor, 50... Control unit, 51... CPU, 52... ROM, 53... RAM, 54... Storage means, 55... Interface , 56...bus.

Claims (6)

a power transmission device having a power transmission coil;
a power receiving device having a power receiving coil;
Measuring means for measuring a change in mutual inductance of the power receiving coil that occurs as the power receiving coil moves;
A control means for controlling power transmission of the power transmission device;
Equipped with
The power receiving device is movably provided at a position facing the plurality of power transmitting devices arranged in succession,
The control means controls power transmission from the power transmission device based on the change in the mutual inductance,
The measuring means is a measuring means for measuring a change in the mutual inductance of each of the power transmission devices,
The control means is characterized in that when the change in the mutual inductance of the adjacent power transmission devices is within a predetermined same value range, the control means starts or stops power transmission of the power transmission device.
Wireless power supply system. The control means starts power transmission from the power transmission device when the amount of change in the mutual inductance is equal to or greater than a predetermined start threshold, and starts the power transmission from the power transmission device when the amount of change in the mutual inductance is equal to or less than a predetermined stop threshold. characterized by stopping power transmission from the power transmission device;
The wireless power supply system according to claim 1. The power receiving device moves along a rail provided in a position parallel to the plurality of power receiving coils,
When the power receiving device moves, the center of the power receiving coil passes directly above the center of the power transmitting coil,
The wireless power supply system according to claim 1 or 2. The length of the outer diameter of the power transmitting coil is 1.0 times or more and 1.5 times or less the length of the outer diameter of the power receiving coil,
The wireless power supply system according to any one of claims 1 to 3. A control method for controlling the wireless power supply system according to any one of claims 1 to 4, comprising :
a power transmission step of controlling power transmission from the power transmission device based on the change in the mutual inductance;
characterized by comprising;
Control method for wireless power supply system. A program for causing one or more computers to execute each step of the method for controlling a wireless power supply system according to claim 5.

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