JPH11206043A - Non-contact type power feeding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To supply a current without phase difference, even when currents are supplied from a plurality of high frequency power supplies to a power feeding line, with regard to a non-contact type power feeding apparatus. SOLUTION: A current supplied to a power feeding line from a high frequency power supply 15 is detected by a current transformer(CT) 1 as, for example, a current of reference phase and is then compared by a PLL circuit 17 with a current to the power feeding line from a high frequency power supply 16 which is detected by CT2. A current is supplied to the power feeding line from the high frequency power supply 16, by driving a chopper circuit 26 with a drive pulse in accordance with the phase difference of both currents. In this case, a current supplied to power feeding lines 12a, 12b from the high frequency power supplies 15 and 16 has no phase difference for preventing the generation of power loss and power supply failures.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact power supply apparatus for supplying electric power to an electric vehicle in a non-contact manner.

[0002]

2. Description of the Related Art At present, self-propelled vehicles for transporting parts and products in factories, such as vehicles for overhead traveling and vehicles for automatic warehouses, are known as electric vehicles. As one of means for supplying electric power to such an electric vehicle, a non-contact power supply device for supplying electric power to the vehicle in a non-contact manner has been proposed.

FIG. 6 is a diagram for explaining a conventional non-contact power supply device. In FIG. 1, a support 3 for supporting a power supply line 2 is attached to a side surface of a rail 1 provided on a ceiling or a floor of a factory. An E-shaped core 4 attached to a vehicle (not shown), which is a moving body, is disposed such that the power supply line 2 is located in a concave portion thereof, and is induced in the E-shaped core 4 by flowing a high-frequency current through the power supply line 2. To drive the vehicle using the electrical power generated.

The supply of power to the power supply line 2 is performed, for example, by high-frequency power supplies 5 and 6 provided at both ends of the power supply line 2. The high-frequency power supply 5 supplies power to the power supply line 2a on the left side of the dashed line shown in the figure, and the high-frequency power supply 6 supplies power to the power supply line 2b on the right side of the dashed line shown in the figure. Therefore, each of the power supply lines 2
The ends of a and 2b are located.

FIG. 7 is a circuit block diagram of a conventional high frequency power supply 5 (or 6). An AC current supplied from an AC power supply (commercial power supply) is converted into a DC current by a rectifier circuit 7 and supplied to a chopper circuit 8. The chopper circuit 8 is supplied with a drive pulse of a predetermined cycle (for example, a frequency of 10 KHz) output from the drive pulse generation circuit 10,
The chopper circuit 8 converts a DC current into an AC current according to the output frequency of the drive pulse, and supplies the AC current to the above-described power supply line 2a (or 2b). Note that the drive pulse output from the drive pulse generation circuit 10 is created by dividing the frequency of the reference pulse of the reference pulse generation circuit 9 provided in the preceding stage.

The above-described circuit configuration is the same in the high-frequency power supplies 5 and 6, and outputs the above-described alternating current based on a reference pulse output from a reference pulse generating circuit 9 incorporated therein.

[0007]

The following problems occur in the above-mentioned conventional wireless power feeding device. That is, since the above-described reference pulse generation circuits 9 are provided independently of each other, there may be a phase difference between the two pulses even if the output frequencies match.

In such a case, a phase difference occurs between the currents output from the high-frequency power sources 5 and 6, and the E-shaped core 4
When straddling a and 2b, power is wasted.
For example, as shown in FIG.
If there is a phase difference of 0 degree, the electromotive force induced in the E-shaped core 4 described above is generated in the opposite direction.
Since the outputs of the two power supplies are short-circuited, problems such as overcurrent abnormality occur in the high-frequency power supplies 5 and 6.

In order to eliminate the phase difference between the high-frequency power supplies 5 and 6, a high-frequency power supply shown in FIG. 9 has been proposed. That is, the reference pulse generation circuit 9 is used in common, and the reference pulse is supplied from the same reference pulse generation circuit 9 to the high-frequency power supplies 5 and 6 (drive pulse generation circuits 10a and 10b), and the power supply line is supplied via the chopper circuits 8a and 8b. 2a,
2b is to supply power without a phase difference.

However, even if the reference pulses are matched, a phase difference occurs between the currents output from the high-frequency power sources 5 and 6 due to differences in the line capacitance between the power supply lines 2a and 2b and differences in inductance.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a non-contact power supply device that more reliably eliminates a phase difference of a current supplied to a power supply line.

[0012]

According to a first aspect of the present invention, there is provided a power supply system comprising:
A second high-frequency power supply; first measuring means for measuring a phase of a current supplied from the first high-frequency power supply;
Measuring the phase of the current supplied from the high frequency power supply of the second
Measuring means, and a phase difference detecting means for comparing the phase of the current measured by the first measuring means with the phase of the current measured by the second measuring means, and detecting a phase difference between the two currents. Controlling the drive pulse supplied to the second high-frequency power supply according to the phase difference detected by the phase difference detection means, and outputting the phase of the current output from the second high-frequency power supply from the first high-frequency power supply This can be achieved by providing a contactless power supply device that matches the phase of the current to be applied.

Here, the power supply line is a power supply line provided along a rail for an automatic warehouse, a rail for an overhead traveling vehicle, or the like, and for example, a litz wire or the like is used. Further, the first and second high-frequency power supplies are provided at both ends of the power supply line, in the middle of the travel path, or at a branch travel path, and supply power to the power supply line at a predetermined cycle. Further, the first and second measuring means measure the phase of the current supplied to the feeder line, and
T (current transformer) and the like. Further, the phase difference detecting means detects the phase difference of the current measured by the first and second measuring means.

With this configuration, a high-frequency current whose phase difference has been corrected is supplied from the second high-frequency power supply in accordance with the phase difference between the two currents detected by the phase difference detection means,
A high-frequency current having no phase difference is supplied from the second high-frequency power supply.

For example, when the phase difference between the two currents is large, the output timing of the drive pulse is largely shifted, and when the phase difference is small, the shift amount of the output timing of the drive pulse is reduced so that the phases of the two currents coincide. I do. Therefore, the phases of the currents output from the first and second high-frequency power supplies are automatically controlled in the same direction, and the phase control of the supplied current can be performed without adjusting the reference pulse or the like.

According to a second aspect of the present invention, there is provided a high frequency power supply for supplying power to a power supply line, and a current phase reference signal serving as a reference for a current phase of the high frequency power supply. Reference signal output means, measurement means for measuring the phase of the current output from the high-frequency power supply, and comparing the phase of the current measured by the measurement means with the phase of the reference signal output from the reference signal output means A phase comparison unit, a current supply unit that creates a current of a predetermined frequency from the phase difference detected by the phase comparison unit, and supplies the current to the power supply line;
This can be achieved by providing a non-contact power supply device having the following.

This embodiment is a non-contact power supply device in which two or more high-frequency power supplies are connected to a power supply line, and the power supply line is, for example, a rail for an automatic warehouse, a rail for an overhead traveling vehicle, or the like, as in the above-described case. The first and second high-frequency power supplies are disposed at both ends of the power supply line, in the middle of the travel path, or in the branch travel path, and supply power to the power supply line in a predetermined cycle. I do. The measuring means is also constituted by, for example, CT or the like. On the other hand, the reference signal generating means is a signal generating means serving as a reference when comparing current phases. For example, a signal including appropriate current phase information is set in advance as a reference signal.

With this configuration, the phases of the currents output from the two or more high-frequency power supplies are automatically controlled in the same direction, and the phase of the supplied current is controlled without adjusting the reference pulse. be able to.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 2 is a system configuration diagram of the contactless power supply device of the present embodiment. Also in this example, the high-frequency power supplies 15
16 are provided. Here, the power supply line 12 (12a,
12b) is attached at predetermined intervals to a support 13 provided on the side surface of the rail 11. Also, the above-mentioned rail 1
The moving body 14 travels along 1 and the driving force of the moving body 14 is received by a core (E-shaped core) 14a. Here, feed line 1
A current supplied from the high-frequency power supply 15 flows through 2a, and a current supplied from the high-frequency power supply 16 flows through the power supply line 12b. Each of the power supply lines 12a and 12b is shown in FIG.
12a ′ and 12b ′ shown in FIG.

FIG. 3 shows the power supply line 12a (or 12b) described above.
2 is a sectional view showing the positional relationship of the E-shaped core 14 with respect to FIG. As shown in the figure, two power supply lines 12a (12
b) is located in two concave portions of the E-shaped core 14a, and forms a magnetic flux created by a current flowing through the power supply line 12a (12b) in the E-shaped core 14a. A current generated by the magnetic flux flows through the coil 14b, and supplies the current to a drive motor or the like in the moving body 14.

On the other hand, a power supply line 1 constituting a non-contact power supply device
As described above, power is supplied to 2a or 12b from the corresponding high-frequency power supply 15 or 16, and FIG. 1 shows this configuration. Although the high-frequency power supplies 15 and 16 shown in FIG. 1 are shown close to each other, they are actually located at a distance of, for example, several hundred meters.

The high frequency power supply 15 supplies power to the power supply line 12a, and the high frequency power supply 16 supplies power to the power supply line 12b. Further, a CT1 is provided at a position of the power supply line 12a near the high-frequency power supply 15, and a current flowing through the power supply line 12a is detected by the CT1. This current is supplied to the PLL circuit / VCO circuit 17 of the high frequency power supply 16. Further, a CT2 is provided at a position of the power supply line 12b near the high-frequency power supply 16, and a current flowing through the power supply line 12b is detected.
It is supplied to the L circuit / VCO circuit 17. Hereinafter, the circuit of FIG. 1 will be specifically described.

FIG. 4 shows a circuit in the high-frequency power supply 15 described above.
1, a rectifier circuit 22 and a chopper circuit 23. The reference pulse generation circuit 20 is configured by an oscillation circuit such as a crystal oscillator, for example, and supplies an oscillation pulse to the drive pulse generation circuit 21. The drive pulse generation circuit 21 divides the frequency of the input oscillation pulse, creates a drive pulse of, for example, 10 KHz, and outputs it to the chopper circuit 23. On the other hand, the rectifier circuit 2
2 is supplied with an alternating current, converted into a direct current by the rectifier circuit 22, and then supplied to the chopper circuit 23.

The chopper circuit 23 includes the rectifier circuit 22 described above.
, A driving pulse is supplied from a driving pulse generating circuit 21, and a chopper circuit 23 turns on and off the DC current according to the supplied driving pulse, and supplies a high-frequency current of, for example, 10 KHz to the power supply line 12a.

On the other hand, as shown in FIG. 1, the high-frequency power supply 16 includes a PLL / VCO circuit (hereinafter simply referred to as a PLL circuit) 17, a drive pulse generation circuit 24, a rectifier circuit 25,
It comprises a chopper circuit 26. A detection current is supplied from the CT1 to the PLL circuit 17 and a detection current is further supplied from the CT2 to be a comparison value of the PLL circuit 17.
The above-described two detection currents are supplied to a phase comparator (not shown) in the PLL circuit 17, and the phase comparator compares the phases of the two currents.

The result of the comparison by the comparator is output to a VCO (voltage control oscillator), a reference pulse is created based on the result of the comparison, and this data is supplied to a drive pulse generation circuit 24. The drive pulse generation circuit 24 outputs a drive pulse according to the reference pulse to the chopper circuit 26. Further, the rectifier circuit 25 rectifies the alternating current and supplies the rectified current to the chopper circuit 26, similarly to the rectifier circuit 22 described above.

The chopper circuit 26 outputs a rectified current supplied from the rectifier circuit 25 to the power supply line 12b as a drive pulse output from the drive pulse generation circuit 24, for example, as a high-frequency current of 10 KHz.

The processing operation of the contactless power supply device having the above configuration will be described below. First, the reference pulse generation circuit 20 is driven, and the oscillation pulse is supplied to the drive pulse generation circuit 21.
From the drive pulse generation circuit 21 to the chopper circuit 2
3 and a high-frequency current is supplied from the chopper circuit 23 to the power supply line 12a.

The high-frequency current flows through the power supply line 12a by the current supplied from the high-frequency power supply 15,
a is supplied with power. This current has a frequency of 10 KHz, and has a phase that matches the conditions for disposing the power supply line 12a. The CT 1 detects a current flowing through the distribution line 12 a and supplies the current to the PLL circuit 17.

On the other hand, the high frequency power supply 16 also starts to drive, and a current is supplied from the high frequency power supply 16 to the power supply line 12b. The detection current from the CT2 provided on the power supply line 12b is also supplied to the PLL circuit 17, the phases of both currents are compared by the phase comparator in the PLL circuit 17, and the driving pulse generation circuit 24 is connected via the VCO. Is output to

The drive pulse supplied to the drive pulse generation circuit 24 is for a current actually flowing through the power supply lines 12a and 12b. Therefore, the feed line 12 is actually
The drive pulse generating circuit 24 is supplied with a pulse signal including such information on the frequency and phase of the current flowing through the a and 12b. That is, the current supplied to the power supply lines 12a and 12b is a current obtained by correcting the phase of the current measured by CT2 using the current detected by CT1 as a reference, for example.

Therefore, the current between the feed lines 12a and 12b and the difference in inductance corresponding to the length of the feed lines 12a and 12b are corrected currents. On the other hand, it is a current whose frequency and phase match. By supplying such a current, even if high-frequency currents are supplied from the two high-frequency power supplies 15 and 16, currents having no phase difference with each other are supplied to the power supply lines 12a and 12b.
Can be supplied to

In the above embodiment, CT1 and CT2
The current was directly measured from the power supply lines 12a and 12b by using the current phase reference pulse generation circuit 2 as shown in FIG.
A configuration may be adopted in which a reference pulse is supplied from 8 to each of the high frequency power supplies 15, 16 and the like.

That is, as shown in FIG. 3, the high-frequency power supplies 15, 16,.
..Output of current phase reference pulse to each high-frequency power source 1
Are supplied to the PLL circuits 29 in 5, 16,... PL
Current data is input to the L circuit 29 from the CT provided on the power supply line 12a, and the PLL circuit 29 compares the two currents and outputs the comparison result to the drive pulse generation circuit 30. Also in this case, the pulse signal supplied to the drive pulse generation circuit 30 is a signal obtained by comparing the measured value of the current flowing through the power supply line 12a with the reference pulse, and accordingly, the 10 KHz drive output from the reference pulse generation circuit 30 is output. The pulse is a pulse whose phase is corrected by the PLL circuit 29, and a current having no phase difference is supplied to each of the power supply lines 12a, 12b, and the like.

[0035]

As described above, according to the present invention, even when power is supplied from a plurality of high-frequency power supplies, there is no phase difference in the supplied power, so that power loss can be prevented.

Further, no contradictory magnetic field is generated in the core, and no overcurrent abnormality or the like occurs in the high-frequency power supply.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram of a high-frequency power supply.

FIG. 2 is a system configuration diagram of the wireless power supply device according to the embodiment;

FIG. 3 is a sectional view showing a positional relationship of an E-shaped core with respect to a power supply line.

FIG. 4 is a diagram illustrating a part of a specific circuit in a high-frequency power supply.

FIG. 5 is a modification of the high-frequency power supply circuit.

FIG. 6 is a diagram illustrating a conventional wireless power supply device.

FIG. 7 is a circuit block diagram of a conventional high-frequency power supply.

FIG. 8 is a diagram illustrating an example in which there is a 180-degree phase difference between both high-frequency power sources, currents output from both high-frequency power sources are canceled, and large amounts of power are wasted.

FIG. 9 is a circuit block diagram showing another example of a conventional high-frequency power supply.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Rail 12a, 12b Feeding line 13 Support 14 Moving body 14a E-shaped core 14b Coil 15, 16 High frequency power supply 17, 29 PLL circuit 20 Reference pulse generation circuit 21, 30 Drive pulse generation circuit 22 Rectifier circuit 23 Chopper circuit 24 Drive pulse Generation circuit 25 Rectifier circuit 26 Chopper circuit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // B65G 54/02 H01F 23/00 Q

Claims (2)

[Claims] A first high-frequency power supply for supplying power to a power supply line; a first measuring unit for measuring a phase of a current supplied from the first high-frequency power supply; and a second high-frequency power supply. A second measuring means for measuring a phase of a current supplied from a power supply; a phase of the current measured by the first measuring means;
Phase difference detecting means for comparing the phase of the current measured by the measuring means with the phase difference between the two currents, and supplying the phase difference to the second high frequency power supply according to the phase difference detected by the phase difference detecting means. A non-contact power supply device that controls a driving pulse to be applied and makes a phase of a current output from the second high-frequency power supply coincide with a phase of a current output from the first high-frequency power supply. 2. A high-frequency power supply that supplies power to a power supply line, a reference signal output unit that outputs a current phase reference signal serving as a reference of a current phase of the high-frequency power supply, Measuring means for measuring the phase of the current to be measured, phase comparing means for comparing the phase of the current measured by the measuring means with the phase of the reference signal output from the reference signal output means, and detecting by the phase comparing means And a current supply unit that generates a current of a predetermined frequency from the phase difference and supplies the current to the power supply line.