JPH10201144A - Power-supply apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase current fed to a transmission line while reducing the current capacity of an inverter by using a curred-fed inverter and a parallel resonance circuit, and to simplify the whole apparatus structure with small size and lightweight. SOLUTION: While a current-fed inverter 5 and a parallel resonance circuit are used, a high-frequency current is supplied to a power-supply line 11. A reactor 6 both for current control and for commutation is installed at the current-fed inverter 5. Transistors 7, 8 as switching elements are connected respectively across a rectifying circuit 2 and one end of the reactor 6 and across the other end of the reactor 6 and the rectifying circuit 2. The power-supply line 11 and a capacitor 12 for resonance are connected in parallel across the intermediate part of the reactor 6 and a neutral point. Then, the changeover operation of the respective transistors 7, 8 is controlled, and the high-frequency current is made to flow to the power-supply line 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device applied to a power supply facility for an article transport cart.

[0002]

2. Description of the Related Art Conventionally, there have been known various power supply devices for supplying electric power from an external source to a moving body, such as a transport trolley, traveling along a rail track. As a device suitable for use in a place, for example, as shown in Japanese Patent Application Laid-Open No. 5-207606, by supplying power in a non-contact manner using electromagnetic induction, dust and sparks caused by wear of a sliding contact portion are reduced. 2. Description of the Related Art A non-contact power supply equipment capable of preventing occurrence is known.

In this non-contact power supply equipment, a power transmission line is arranged along a rail track, a high-frequency current flows from a power supply device having an inverter to the power transmission line, and a pickup coil is mounted on a core member made of a magnetic material. Is mounted on a transport trolley so that an induced electromotive force corresponding to a high-frequency current flowing through a transmission line is generated in a pickup coil.

In such a power supply device (contact power supply device) of a non-contact power supply system, it is necessary to reduce the current capacity of an inverter while allowing a relatively large current to flow through a transmission line.
It is desirable to provide a parallel resonance circuit by providing a capacitor in parallel with the transmission line, and to cause a current larger than the inverter current to flow through the transmission line due to the resonance phenomenon. In this case, if a voltage type inverter is used as the inverter,
The parallel resonance circuit cannot be driven directly. For this reason, in a conventional device of this type as disclosed in the above-mentioned publication, a current source inverter is used, a transmission line is connected to the output side, and a resonance capacitor is connected in parallel with the transmission line. ing.

FIG. 5 schematically shows a conventional power supply device having the above-described current-source inverter. In the power supply device of this figure, a rectifier circuit 2 is connected to a three-phase AC power supply 1,
A capacitor 101, a diode 102, a transistor 103, and a current control reactor 104 are connected to an output side thereof, so that a constant current is obtained by the reactor 104 and the like, and a commutation reactor 105 is connected to the current control reactor 104. Are connected to both ends of the commutation reactor 105. Transistors 106 and 107 which perform switching operations are connected to both ends of the commutation reactor 105. A power supply line is connected between each end of the commutation reactor 105 and each of the transistors 106 and 107. (Transmission line) 108 and resonance capacitor 109 are connected.

[0006]

The above-described conventional device has at least two reactors 104 and 105 for current control and commutation, and has a transistor 103 for controlling a constant current and an inverter function. Requires at least three switch elements, ie, two transistors 106 and 107, and the structure is complicated. In particular, since the reactor is relatively large and heavy, the reactors 104 and 104 are separately used for current control and commutation.
Providing 105 causes a problem that the entire apparatus is likely to be increased in size and weight.

In view of the above circumstances, the present invention uses a current source inverter and a parallel resonance circuit to increase the current flowing through a transmission line while reducing the current capacity of the inverter.
It is an object of the present invention to provide a power supply device that can simplify the structure of the entire device and reduce the size and weight.

[0008]

In order to achieve the above object, according to the present invention, a current source inverter is provided on a power supply side of a transmission line so that a high-frequency current flows through the transmission line, and a transmission type inverter is provided on an output side of the inverter. A power supply device to which a resonance capacitor forming a parallel resonance circuit is connected to an electric wire, wherein a current control and commutation reactor is connected to an output side of a DC power supply circuit obtained by connecting a rectifier circuit to an AC power supply, A switching element is provided between the DC power supply circuit and one end of the reactor and between the other end of the reactor and the DC power supply circuit, respectively, between the intermediate portion of the reactor and a neutral point of the AC power supply, and a transmission line. A control device for connecting a resonance capacitor in parallel with each other and for causing a high-frequency current to flow through the transmission line by the switching operation of each switch element is provided.

According to this device, the direction of the current flowing in the transmission line is changed by the switching operation of each of the switch elements, thereby functioning as a current source inverter, and the resonance operation of the resonance capacitor is performed to the transmission line. Current is efficiently supplied. Further, since the reactor serves both for current control and for commutation, the number of reactors is reduced as compared with the case where the current control reactor and the commutation reactor are separately provided. Also, the number of switch elements is reduced as compared with the conventional device.

[0010] In the apparatus of the present invention, the transmission line is provided on a transfer path in an article transfer system, and a transfer carriage movable along the transfer path is provided with electromagnetic induction in accordance with a high-frequency current flowing through the transmission line. When a power-supplying body that generates an electromotive force is provided, non-contact power feeding by electromagnetic induction from a power transmission line is effectively performed on the transport vehicle.

[0011]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a circuit diagram showing an embodiment of the power supply device of the present invention. In FIG. 1, reference numeral 1 denotes a three-phase AC power supply, and reference numeral 2 denotes a rectifier circuit (DC power supply circuit) connected to the AC power supply 1. The rectifier circuit 2 includes six diodes 3 and converts three-phase alternating current into direct current.

A current source inverter 5 is connected to the output side of the rectifier circuit 2. The inverter 5 includes a reactor 6 for current control and commutation, and is connected between the plus terminal of the rectifier circuit 2 and one end of the reactor 6 and between the other end of the reactor 6 and the minus terminal of the rectifier circuit 2. It has a switching element composed of transistors 7 and 8 connected between them. That is, the transistor 7, the reactor 6, and the transistor 8 are connected in series to the output side of the rectifier circuit 2.

A high-frequency output side circuit 10 is connected between the intermediate portion 6a of the reactor 6 and the neutral point 9 of the AC power supply 1, and the high-frequency output side circuit 10 resonates with a power supply line (transmission line) 11. And a parallel resonance circuit connected in parallel with each other.

A pair of smoothing capacitors 21 and 22
Is connected to the rectifier circuit 2 in parallel with the transistor 7, the reactor 6, and the transistor 8, the neutral point 9 is connected between the pair of smoothing capacitors 21 and 22, and the pair of diodes 23 and 24 Are connected in parallel with the reactor 6, and the pair of diodes 23,
The point between 24 is connected between the reactor 6 and the high-frequency output side circuit 10.

The transistors 7 and 8 are connected to the control device 3
Controlled by 0, the switching operation is repeated at a predetermined frequency while the phases are shifted from each other. Further, the parallel resonance circuit that constitutes the high-frequency output circuit 10 resonates at the fundamental frequency of the inverter 5 (the frequency at which the transistors 7 and 8 operate). That is, assuming that the capacitance of the capacitor 12 is C and the inductance of the power supply line 11 is L, the resonance frequency f of the parallel resonance circuit is as follows.

F = {1 / (2π)} · {1 / {(CL)} The basic frequency, the inductance L of the power supply line 4 and the resonance frequency f are adjusted so that the resonance frequency f matches the basic frequency of the inverter 5. The capacity C of the capacitor 12 is set.

FIG. 2 shows the internal structure of the control device 30. The control device 30 includes a control amplifier 31, a PWM
A circuit 32 and a gate drive circuit 33 are included. The input side of the control amplifier 31 is supplied with a line current command value from an external command means (not shown),
The line current detection value is given from 1 and the output of the control amplifier 31 is controlled according to the deviation of these values.

The PWM circuit 32 outputs a PWM signal corresponding to the control amplifier 31, and the gate drive circuit 33
In response to a signal from the WM circuit 32, drive signals a and b are output to the gates of the transistors 7 and 8, respectively. In this case, the drive signals a and b are
The signal a for the transistor 7 and the signal b for the transistor 8 are shifted from each other by a half cycle. The duty of each of the signals a and b (the ratio of the ON time t to the cycle) is adjusted according to the deviation between the command value of the line current and the detected value. That is, when the detected value of the line current is larger than the command value, the duty of each signal a, b is gradually reduced, and when the detected value is smaller than the command value, the duty of each signal a, b is gradually increased. You. The maximum duty of each of the signals a and b is set to 50% so that the control times of the signals a and b do not overlap.

FIG. 3 and FIG. 4 schematically show the structure of the power transmission line arrangement portion and the power-supplied side when the above-mentioned power supply device is applied to an article transport system. In these figures, 4
Reference numeral 0 denotes a monorail that constitutes a transport route, which is disposed in an elevated state in a factory or the like, is supported by a ceiling portion or the like via a bracket 41, and the power supply line 11 is connected to one side of the monorail 40. The constituent transmission lines are provided. The transmission line is connected to a power supply 42 at one end of the monorail 40.
Is connected to the other side of the monorail 40 via a hanger 43 in a state of being looped at the other end of the monorail 40. The power supply device 42 includes the AC power supply 1, the rectifier circuit 2 shown in FIG.
An inverter 5 and the like are provided.

On the monorail 40, a carrier 45 is movably supported. The transport vehicle 45 includes traveling wheels 46 that roll on the monorail 40 and the monorail 4.
The power feeder is provided with guide rollers 47 and 48 in contact with the upper side, lower side, and lower surface of the motor 0, a motor 49 for driving the running wheels 46, and the like. The pickup unit 50 is provided. The pickup unit 50 includes a core member 5 made of a magnetic material and having a substantially E-shaped cross section.
1 and a pickup coil 52 wound around a central protruding portion 51 a of the core member 51, and are arranged so as to correspond to the power supply line 11 arranged on the monorail 40. When an alternating current flows through the power supply line 11, a magnetic flux is formed using the core member 51 as a magnetic path, an electromotive force generated by electromagnetic induction is generated in the pickup coil 52, and the electromotive force is transmitted via a controller (not shown). The motor 49 is supplied to the motor 49.

The operation of the above-described power supply device according to the present embodiment will be described below.

By performing non-contact power supply by electromagnetic induction from the power supply line 11 to the pickup unit 50 of the transport carriage 45, dust and sparks are not generated due to abrasion unlike contact power supply. ,
Suitable for use in clean rooms. Then, for this non-contact power supply, a high-frequency current flows from the power supply device 42 including the inverter 5 to the power supply line 11.

In this case, the transistors 7 and 8 of the inverter 5 are driven by a signal from the control device 30, so that a high-frequency alternating current is obtained. That is, when the transistor 7 is turned on, the current flows from the positive terminal of the rectifier circuit 2 to the neutral point via the transistor 7, one half of the reactor 6 (the upper half in FIG. 1) and the high frequency output side circuit 10. On the other hand, when the transistor 8 is turned on, the negative terminal of the rectifier circuit 2 passes from the neutral point via the high frequency output side circuit 10, the other half of the reactor 6 (the lower half in FIG. 1) and the transistor 8. The current flows to. As a result, the current flowing through the power supply line 11 is
The switching is performed as a solid arrow when N, and as a broken arrow when the transistor 8 is ON. A high frequency alternating current is obtained by the inverter operation in which such commutation is repeated.

Further, since the resonance capacitor 12 is provided in parallel with the power supply line 11, the current supplied to the power supply line 11 is increased while the current capacity of the inverter 5 is reduced. Further, although the function as the current source inverter 5 alone results in a square wave alternating current,
The output is approximated to a sine wave by the resonance circuit.

As described above, the power supply line 1 is provided by the power supply device in which the parallel resonance circuit is incorporated in the current source inverter 5.
1 is effectively supplied. Moreover, the size and weight can be reduced as compared with the conventional apparatus as shown in FIG. That is, in the conventional apparatus shown in FIG. 5, heavy reactors 104 and 105 are provided separately for current control and commutation, whereas
In the apparatus of the present embodiment, one reactor 6 is used for both current control and commutation, so that the weight is reduced and the size is reduced. In the above-described conventional device, the transistors 103, 106, and 107, which are switching elements, are 3
In contrast to the necessity, two transistors 7 and 8 may be used in the device of the present embodiment, which is advantageous for miniaturization and weight reduction.

In the examples shown in FIGS. 3 and 4, the apparatus of the present invention is applied to a monorail type transport system.
In addition, the apparatus of the present invention can be used to supply power to various moving bodies and the like that move along a fixed path with electric driving means.

[0027]

As described above, the power supply device of the present invention supplies a high-frequency current to a transmission line using a current-source inverter and a parallel resonance circuit. The high-frequency current can be effectively supplied to the power supply. In addition, a reactor for current control and commutation is provided, and switch elements are provided between the DC power supply circuit and one end of the reactor and between the other end of the reactor and the DC power supply circuit, respectively. Since the transmission line and the resonance capacitor are connected in parallel between the points and the switching operation of each switch element is controlled, the number of reactors and switch elements is reduced, and the weight and size are reduced. Can be planned.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing one embodiment of a power supply device of the present invention.

FIG. 2 is a block diagram of a control unit of the power supply device.

FIG. 3 is a schematic front view of an article transport system to which the power supply device is applied.

FIG. 4 is a schematic sectional view of a main part of the transport system.

FIG. 5 is a circuit diagram illustrating an example of a conventional power supply device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 AC power supply 2 Rectifier circuit 5 Inverter 6 Reactor for current control and commutation 7, 8 Transistor (switch element) 9 Neutral point 11 Power supply line (power transmission line) 12 Resonant capacitor 30 Control device

Claims (2)

[Claims] 1. A power supply device in which a current source inverter is provided on a power supply side of a transmission line so that a high-frequency current flows through the transmission line, and a resonance capacitor forming a parallel resonance circuit with the transmission line is connected to an output side of the inverter. A rectifier circuit is connected to an AC power supply, a DC power supply circuit is connected to a current control and commutation reactor, and the DC power supply circuit is connected to one end of the reactor and the other end of the reactor. And a DC power supply circuit, a switching element is provided between the intermediate part of the reactor and a neutral point of the AC power supply, and a transmission line and a resonance capacitor are connected in parallel with each other. A control device for causing a high-frequency current to flow through the transmission line by the switching operation of the power supply device. 2. An electromotive force generated by electromagnetic induction according to a high-frequency current flowing through the transmission line, wherein the transmission line is disposed on a transportation path in an article transportation system, and the carriage is movable along the transportation path. The power supply device according to claim 1, further comprising a power-supplied body.