JPH1070856A - Constant voltage induction feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically restrict a supply voltage even though an on-land moving body gas a light load or no load, by providing a pickup coil turned around an iron core of the on-land moving body and connecting an over saturable reactor to its pickup coil in parallel. SOLUTION: A power supply line 20 laid along a running way is used as a primary side, a pickup coil 34 wound around an iron core 32 provided on an on-land moving body 30 is used as a secondary side, and power supply is performed to a pickup coil 34 by the electromagnetic induction. At this time, a resonance capacitor 38 and a saturable reactor 40 are connected in parallel to the pickup coil 34. A self-inductance of this saturable reactor 40 is determined in such a manner that a voltage occurs at both the ends of the pick-up coil 34, when a load 37 is turned off, becomes a voltage which will not destroy semiconductor elements used in a rectifying circuit 35 and a constant voltage output device 36. By this, the feeding voltage can be automatically restricted even if the on-land moving body 30 becomes a light load or no load.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant voltage power supply apparatus for supplying power to a ground moving object, and more particularly to a constant voltage induction power supply apparatus which automatically regulates a secondary voltage according to a load state.

[0002]

2. Description of the Related Art A conventional power supply device for supplying power to a ground moving object will be described with reference to the drawings. FIG. 7 is a side sectional view for explaining a main part of the device, and FIG. 8 is an electric circuit diagram. FIG.
In this embodiment, an unillustrated traveling rail on which a traveling wheel of the ground moving body 30 rolls is provided on an unillustrated traveling path laid on the ground 11, and a holding mechanism for holding the power supply line 20 on a side surface of the traveling path. The fixture 21 is fixed to a base 22 provided on the traveling path.

A plurality (two in the illustrated example) of an E-shaped iron core 32 is provided on the ground moving body 30 on the side surface in the longitudinal direction of the vehicle body via a support seat 33 so as to face the power supply line 20.
A pickup coil 34 is wound around the central leg of the iron core 32.

As shown in FIG. 8, a feed line 20 has a base end connected to a high-frequency power supply 23 and a front end connected to form a single loop. The two opposite lines are configured to be located at both openings 32A sandwiching the central leg of the iron core 32. The opening 32A of the iron core 32 is
And the holder 21 is formed in such a size that the holder 21 can pass through.

When a high-frequency current flows from the high-frequency power supply 23 to the power supply line 20, an induced voltage is generated in the pickup coil 34 by an electromagnetic induction action in which the power supply line 20 serves as a primary side and the pickup coil 34 serves as a secondary side. The AC voltage generated by this voltage is applied to the rectifier circuit 35 and the constant voltage output device 3.
The voltage is converted into a predetermined voltage via 6 and supplied to a load 37 such as a drive motor of the ground moving body 30. Thus, the power is supplied to the power supply line 20 in a non-contact manner while the ground moving body 30 is traveling. In the figure, 38 is a resonance capacitor that resonates with the pickup coil 34, and A is a resonance circuit. Also 2
Reference numeral 4 denotes a tuning capacitor provided on the primary side, which can be omitted when the length of the feed line 20 is short.

In the above-described power supply device, when the load becomes nearly light or no load, such as when the drive motor of the ground moving body stops, the voltage generated across the pickup coil increases accordingly. . Therefore, there has been a problem that an overvoltage is applied to a rectifier circuit, a constant voltage device, and the like connected to the pickup coil, and a semiconductor element provided in the device is destroyed.

[0007] As means for solving the above-mentioned problems, for example, the invention described in Japanese Patent Publication No. 6-506099 is known. In the above publication, means is provided for preventing a reduced load from being applied to the primary-side feeder line. The following five embodiments are described as the means. First, in the first embodiment, the voltage of the resonance capacitor connected in parallel to the pickup coil is converted into a DC voltage, and the converted DC voltage is compared with a separately provided power supply reference voltage. The switch is turned on / off to maintain the voltage supplied to the load within a predetermined range.

In the second embodiment, an additional coil having a switch is arranged between the primary side feeder line and the pickup coil. The switch is turned on when the voltage of the pickup coil is high, and is turned off when the voltage of the pickup coil is low. The mutual inductance between the line and the pickup coil is changed to maintain the voltage of the pickup coil in a predetermined range.

In the third embodiment, a switch is connected in parallel to a tuning capacitor of a pickup coil, and the circuit is non-resonant and resonates by turning on / off the switch. It is configured to control the amount of power.

Further, in the fourth embodiment, a resistor and a switch are connected in parallel to a load so that a full load is always applied to the pickup coil even if a light load is applied to the load by turning on and off the switch. It is configured to control.

The fifth embodiment is configured to control the amount of electric power transmitted and received between the primary feed line and the pickup coil by moving the pickup coil closer to or away from the primary feed line.

[0012]

However, in each of the above-mentioned embodiments, it is essential to detect the state of the load by some method. In order to detect the state of the load, each of the embodiments has a number of components. However, there is a drawback in that the configuration is complicated and manpower is required for maintenance.
That is, in the first embodiment, a controller such as a comparator in addition to a reference voltage power supply and a switch, and in the second embodiment, a voltage monitoring device for an additional coil, a switch, a pickup coil, and the like are further provided. The fifth embodiment requires a switch and control means for the switch, and the fifth embodiment requires a configuration for moving the pickup coil and a control device.

[0013] Accordingly, the first aspect of the present invention is to provide a constant voltage induction power supply device which automatically regulates the power supply voltage even when the ground moving body is lightly loaded or unloaded. The purpose is.

A second object of the present invention is to provide a constant-voltage induction power supply device which has a simple structure and can be reduced in size and weight, in addition to the object of the first invention.

[0015]

In order to achieve the above-mentioned object, the invention according to claim 1 of the present invention is a power supply which is disposed along a traveling path on which a ground moving body travels and through which a high-frequency current flows. In a constant voltage induction feeding device that feeds a pickup coil by an electromagnetic induction action with a line as a primary side and a pickup coil wound around an iron core provided on a ground moving body as a secondary side, a saturable reactor is connected to the pickup coil. It is characterized by being provided in parallel connection.

According to a second aspect of the present invention, the saturable reactor is a toroidal coil.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of a constant voltage induction power supply apparatus according to the present invention;

FIG. 1 is an explanatory view of the configuration of the device of the present invention, FIG. 2 is an electric circuit diagram of the device of the present invention, FIG. 3 is an equivalent circuit diagram thereof, and FIG. 4 is load current-load of the device of the present invention with and without a toroidal coil. FIG. 5 is a voltage characteristic diagram and a characteristic diagram of self-inductance-load current, and FIG. 5 is a characteristic diagram of self-inductance-load current of the toroidal coil, together with the characteristic diagram of load current-load voltage shown in FIG. FIG. 6 is an electric circuit diagram illustrating another embodiment. The same parts as those of the conventional device are denoted by the same reference numerals.

The device of the present invention differs from the conventional device only in the electrical equipment of the ground moving body 30. That is, the pickup coil 3
4 (two are connected in series in the illustrated example), saturable reactors 40 are connected in parallel at both ends. Other configurations are the same as those of the conventional device.

The primary electrical equipment of the device of the present invention is 10 KHz
The high frequency power supply 23 for generating a high frequency voltage V1, and includes a feed line 20 and the capacitor high-frequency current I ₁ output from the high-frequency power supply device 23 flows.

The secondary-side electric equipment provided on the ground moving body 30 includes two pickup coils 34 electromagnetically coupled to the power supply line 20 and a resonance coil connected in parallel to an output terminal of the pickup coil 34. It includes a capacitor 38 and a saturable reactor 40, a rectifier circuit 35, a constant voltage output device 36, and a load 37. A resonance circuit A is formed between the pickup coil 34 and the resonance capacitor 38.

The saturable reactor 40 is an iron core reactor in which a necessary winding is applied to an iron core. The saturable reactor 40 changes the inductance of the winding by utilizing the nonlinearity of the iron core, and is a known reactor. . The core is a punched core,
An annular core such as ferrite or permalloy is used.

In the embodiment, a toroidal coil 40 is used as a saturable reactor. The self-inductance of the toroidal coil 40 is determined so that the voltage generated across the pickup coil 34 when the load 37 is off is a voltage at which the semiconductor elements used in the rectifier circuit 35 and the constant voltage output device 36 are not destroyed.

Next, the operation of the apparatus of the present invention will be described. When the magnetic flux density of the core of the toroidal coil 40 is B (Gauss), the cross-sectional area of the core is Ae (cm ² ), the number of turns of the coil is N (times), the terminal voltage is V (volt), and the frequency is F (hertz). There is a relationship shown in Equation 1.

[0025]

(Equation 1)

When a ferrite core is used for the toroidal coil 40, if the saturation magnetic flux density of the core exceeds about 4200 gauss, the self-inductance of the toroidal coil 40 decreases, the exciting current increases, and the pickup coil 3
The voltage of No. 4 is kept almost constant.

When an actual load is connected, the self-inductance of the toroidal coil is increased below the saturation voltage at which the iron core is magnetically saturated, so that the reactance becomes larger than the load resistance and the exciting current flows only slightly. Absent.

FIG. 3 is an equivalent circuit diagram of the apparatus of the present invention. The self-inductance of the feed line 20 is L1, the self-inductance of the pickup coil 34 is L2, the mutual inductance between the pickup coil 34 and the feed line 20 is M, and power is supplied. The resistance of the line 20 is R1, the pickup coil 3
4 is R2, the self-inductance and resistance of the toroidal coil are Lt and Rt, respectively, and the primary side capacitor 3
4, the capacitance of the resonance capacitor 38 is represented by C1, and the resistance of the load 37 is represented by RL. The primary voltage is V1, the terminal voltage of the toroidal coil 40, that is, the secondary voltage is V2, and the load voltage is VR.

In the embodiment of the present embodiment, the power supply frequency is set to 1
0 KHz, L1 = 21.8 μH, R1 = 0.052
Ω, C1 = 8.8 μH, L2 = 137.8 μH, R2 =
0.08Ω, C2 = 1.47 μH, Lt = 17.7m
FIG. 4 shows measured values of the load current IR, the load voltage VR, and the secondary voltage V2 when H and Rt = 10.75Ω. FIG. 4 also shows the relationship among the load current IR, the load voltage VR, and the load power W.

In this embodiment, since Lt = 17.7 mH, the reluctance of the toroidal coil 40 is 2πfLt.
≒ 1112Ω, which is about 100 times as large as the load resistance Rt = 10.7Ω, so that only a small current flows through the toroidal coil 40 as described above.

When the load 37 becomes light and the current stops flowing, the voltage of the pickup coil 34 rises.
In this embodiment, Ae = 2.3 cm ² , N = 43 times, Bmax
= 4200 gauss, when the toroidal coil 40 is excited at F = 10 KHZ, if the voltage V is more than 184 volts, the iron core is saturated and the self-inductance Lt decreases. Is maintained at about 180V.

In the figure, a curve A shows a change in the secondary voltage V2 when I ₁ = 70 A and the toroidal coil 40 is provided. Curve B is I ₁ = 70 A, toroidal coil 40
Curve C shows the change in the secondary voltage V2 without
₁ shows changes in the secondary side voltage V2 when ₁ = 60 A and without the toroidal coil 40.

FIG. 5 shows that the mutual inductance M is M =
1.568 × 10 ^-5 H, other Lt, L2, R
2, C2 is the same value as above, power supply frequency 10 KHz,
The graph shows the characteristics of the load voltage and the load current when I ₁ = 60 A and when the toroidal coil 40 is used. In the figure, a curve D has a toroidal coil, and a curve E shows a case without a toroidal coil.
A curve F indicates a load current-self-inductance characteristic of the toroidal coil 40.

As shown in FIG. 5, when the load current Id is large, the voltage of the pickup coil 34 becomes low and the toroidal coil 40 does not saturate, so that the self inductance Lt is large. When the load current Id is small, the voltage of the pickup coil 34 increases, the toroidal coil 40 saturates, the self-inductance Lt decreases, the current of the toroidal coil 40 increases, and the voltage of the pickup coil decreases. ing.

As is clear from FIGS. 4 and 5, the provision of the toroidal coil 40 makes it possible to regulate an increase in the load voltage when the load is light or no load. Therefore, the withstand voltage value of the semiconductor element used for the rectifier circuit 35, the constant voltage output device 36 and the like can be suppressed to a low voltage.

In the curves A and D, the load current IR
By removing the area where the secondary voltage V2 sharply decreases due to the increase in the voltage from the use range, a substantially constant voltage can be obtained, so that the constant voltage output device 36 can be omitted depending on the place of use. In the above description, the pickup coils 34 are connected in series, but it goes without saying that they may be connected in parallel.

Furthermore, in the above embodiment, the ground moving body runs on the running rail provided on the ground, but the present invention is not limited to this. The moving body may be of a suspension type.

In FIG. 6, the toroidal coil 40
5 shows an electric circuit for obtaining a constant voltage by using a Zener diode Zd and a resistor R. However, in this embodiment, the same effect as in the case of using the toroidal coil can be obtained, but power consumption occurs as resistance loss.

[0039]

As described above, according to the first aspect of the present invention, the power supply line disposed along the traveling path on which the ground moving body travels and through which high-frequency current flows is set as the primary side, and In a constant voltage induction feeding device for feeding power to a pickup coil by electromagnetic induction, with a pickup coil wound around an iron core provided on a body as a secondary side, a saturable reactor is provided in parallel with the pickup coil. Features.

Therefore, since the secondary voltage is automatically regulated in accordance with the state of the load, it is not necessary to separately provide a means for detecting the state of the load as found in the conventional apparatus. . In addition, the withstand voltage value of the semiconductor element used for the rectifier circuit or the like can be made lower than that of the conventional device, and the cost of equipment can be greatly reduced because a constant voltage output device does not need to be provided.

According to a second aspect of the present invention, in addition to the first aspect, the saturable reactor is constituted by a toroidal coil. In addition to the effect of the first aspect, the structure is simple and movable. Since there are no parts, aging adjustment after setting is unnecessary, and maintenance becomes extremely easy.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a configuration of a device of the present invention.

FIG. 2 is an electric circuit diagram of the device of the present invention.

FIG. 3 is an equivalent circuit diagram of the device of the present invention.

FIG. 4 is a characteristic diagram of load current and load voltage and a characteristic diagram of load current-secondary power of the device of the present invention with and without a toroidal coil.

FIG. 5 is a characteristic diagram of a self-inductance-load current of a toroidal coil.

FIG. 6 is an electric circuit diagram illustrating another embodiment.

FIG. 7 is a side sectional view for explaining a main part of a conventional power supply device.

FIG. 8 is an electric circuit diagram of a conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Runway 20 Feeding line 23 High frequency power supply 30 Ground moving body 32 Iron core 34 Pickup coil 37 Load 38 Resonant capacitor 40 Saturable reactor

Claims (2)

[Claims] 1. A feed line, which is disposed along a traveling path on which a ground moving body travels and passes a high-frequency current, is a primary side, and a pickup coil wound around an iron core provided on the ground moving body is a secondary side. A constant voltage induction feeding device for feeding power to a pickup coil by electromagnetic induction, wherein a saturable reactor is provided in parallel with the pickup coil. 2. The constant voltage induction feeding device according to claim 1, wherein the saturable reactor is a toroidal coil.