JP2002058179A - Mobile unit power supply circuit of noncontact feeder apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mobile unit power supply circuit of a noncontact feeder apparatus, which can output a voltage necessary for a mobile unit, regardless of the positions of receiving parts and can avoid steady unbalance between currents applied to the respective receiving parts. SOLUTION: The mobile unit power supply circuit of this noncontact feeder apparatus comprises 1st and 2nd receiving parts, connected in series with each other, a rectifying part, and 1st and 2nd capacitors (Ca) and (Cb) connected in series to each other. A switch (SW) which makes and breaks the connection between the receiving side middle point (Mi) of the 1st receiving part and the 2nd receiving part and the middle point (Mc) of the 1st capacitor and the 2nd capacitor is provided. With such a constitution, a series power supply circuit and a voltage-doubler power supply circuit can be switched freely to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for receiving AC power from a power supply line to which AC power is supplied in a non-contact manner by electromagnetic induction, and supplying DC power to a load (control circuit, motor, etc.) on a moving body side. The present invention relates to a mobile-side power supply circuit of a wireless power supply device.

[0002]

2. Description of the Related Art As a system for supplying electric power to a driving source of a moving body (for example, a truck traveling along a rail), there are a contact power supply system (trolley system) and a non-contact power supply system. However, in the case of the contact power supply system, metal abrasion powder or sparks may be generated at the contact portion, instantaneous blackout may occur due to poor contact, and a short circuit or electric shock may occur depending on the use environment.
In addition, periodic maintenance and parts replacement are also required. Therefore, a mobile body using a clean, safe and maintenance-free non-contact power supply system is becoming widespread. This non-contact power supply device (non-contact power supply device) usually includes a power supply line to which AC power is supplied from a high-frequency power supply, and a coil (including a core) interlinking an alternating magnetic flux generated by the power supply line. And a rectifying circuit for rectifying the AC power received by the coil, so that the rectified DC power can be supplied to a load (a control circuit, a motor, or the like) on the moving body side.

Incidentally, various types of power supply circuits (rectifier circuits, etc.) arranged on the moving body side in the non-contact power feeding device have been developed. For example, Japanese Patent Application Laid-Open No. 200-7876.
No. 4 and Japanese Patent Application Laid-Open No. 2000-134829 have the disclosure. In JP-A-2000-77864, as shown in FIG. 4, both ends of two power receiving units connected in series are directly connected to a rectifier circuit, and after rectifying AC to DC, one capacitor is charged. A power supply circuit that uses the voltage between both ends of the capacitor as an output voltage (hereinafter, referred to as a “series power supply circuit”) is disclosed. This series power supply circuit has excellent reliability and cost because the circuit configuration is simple.

In Japanese Patent Application Laid-Open No. 2000-134829, as shown in FIG. 5, both ends of two series-connected power receiving units are connected to a rectifier circuit, and an intermediate point is connected between two series-connected capacitors after the rectifier circuit. (Hereinafter, referred to as a "doubled voltage power supply circuit") is disclosed. In this voltage doubler power supply circuit, the two capacitors are charged alternately with the rectified DC voltage generated from each power receiving unit, and the sum of the voltages across the capacitors becomes the output voltage. This voltage doubler power supply circuit also has excellent reliability and cost because the circuit configuration is simple.

[0005]

By the way, if the moving distance of the moving body becomes long, a long power supply line is inevitably required. Has limitations. Therefore, when the moving distance of the moving object is long, a plurality of sets of power supply lines are laid, and AC power is supplied from another high-frequency power source to each power supply line in many cases. However, since the phases are generally different between power supply lines to which AC power is supplied from another high-frequency power supply, if one power receiving unit straddles two sets of power supply lines and receives AC power supply from them simultaneously, The AC power received by the power receiving unit, particularly the AC voltage, becomes unstable, and the operation of the moving body also becomes unstable. For this reason, as disclosed in Japanese Patent Application Laid-Open No. H11-122847, a “parasitic line section” that is longer than the length of each power receiving unit (coil or core) is provided between adjacent separate sets of power supply lines. This prevents interference between different sets of feeders.

However, when the power receiving unit of the mobile body passes through the non-feeding line section, the power receiving unit cannot receive power supply. For this reason, in the case of the above-described series power supply circuit, the AC voltage supplied to the moving body is reduced by half since the power receiving unit is connected in series. Even if it is a short time when passing,
It is not preferable that the operation of the moving body, particularly the operation of the control circuit thereof, becomes unstable. Of course, the above-mentioned JP-A-200
As described in Japanese Patent Application Laid-Open No. 0-134829, it is possible to provide a DC / DC converter or the like to secure a predetermined voltage, but the cost increases.

On the other hand, in the above-described double voltage power supply circuit, even if one power receiving unit is in the non-feeding line section, the capacitors connected in series are charged alternately according to the positive or negative voltage generated in each power receiving unit. Although the state is a half-wave rectification state, the output voltage does not significantly decrease because the sum of the voltages across the capacitors becomes the output voltage. Therefore, even when the moving body is located in the non-feeding line section, its operation does not become unstable. However, in the case of the double voltage power supply circuit,
Unlike the series power supply circuit, the current flowing through each power receiving unit is independent of each other, and therefore, the voltage generated in the power receiving unit may cause an imbalance in the current flowing between both coils. For this reason, even if both power receiving units are supplied with AC power from the same set of power supply lines, an excessive current may flow only in the coil of one of the power receiving units, which may generate more heat than expected.

[0008] The present invention has been made in view of such circumstances. That is, it is possible to provide a moving body side power supply circuit of a non-contact power feeding device which can output a required voltage to the moving body side regardless of the position of the power receiving section and can prevent a steady imbalance of a current flowing through each power receiving section. Aim.

[0009]

Means for Solving the Problems The inventor of the present invention has intensively studied to solve this problem, and after repeated trial and error, came up with the idea that a switching section is provided in the power supply circuit to switch between two types of power supply circuits. This has led to the development of a mobile-side power supply circuit of the contactless power supply device of the present invention. That is, the moving body side power supply circuit of the non-contact power supply device of the present invention includes a power receiving unit that receives AC power by electromagnetic induction in a non-contact state from at least one of a plurality of power supply lines to which AC power is supplied. A rectifying unit that rectifies the AC power received by the power receiving unit into DC power, and an output unit that outputs the DC power obtained from the rectifying unit to a load via a capacitor connected between terminals,
In the power supply circuit on the moving body side of the contactless power supply device comprising
The power receiving unit includes at least two first power receiving units and a second power receiving unit connected in series, and the capacitor of the output unit includes a first capacitor and a second capacitor connected in series, and the first power receiving unit includes A power receiving side intermediate point between the first capacitor and the second power receiving unit; and a switching unit capable of switching connection or disconnection between a capacitor side intermediate point between the first capacitor and the second capacitor. .

When the switching section cuts off the power receiving side intermediate point between the first power receiving section and the second power receiving section and the capacitor side intermediate point between the first capacitor and the second capacitor, the above-described series power supply circuit is substantially turned off. Thus, a similar circuit is formed. At this time,
Since the first power receiving unit and the second power receiving unit are connected in series,
The same current flows in both, regardless of the position of the power receiving part,
Unbalance of current can be prevented. Then, the first capacitor and the second capacitor connected in series function integrally as a smoothing capacitor, and the ripple rate is reduced, that is, smoothing is achieved. On the other hand, the switching unit controls the power receiving side intermediate point between the first power receiving unit and the second power receiving unit, the first capacitor, and the second capacitor.
When the capacitor and the capacitor-side intermediate point are connected,
A circuit substantially similar to the aforementioned voltage doubler power supply circuit is formed. At this time, the first power receiving unit and the second power receiving unit are independently
The first capacitor and the second capacitor are charged alternately according to the polarity of the voltage generated at them. In other words, even if the power supply from one power receiving unit is stopped, both the first capacitor and the second capacitor are charged only by the other power receiving unit. And the first
Since the capacitor and the second capacitor are connected in series, the sum of the voltages across each capacitor becomes the output voltage,
The output voltage does not drop significantly. As described above, since the moving body side power supply circuit of the non-contact power supply device has the switching unit, the disadvantages of the conventional series power supply circuit and the voltage doubler power supply circuit are mutually complemented. That is, it is possible to obtain a moving body side power supply circuit that is low in cost and high in reliability, and that can prevent a steady imbalance of current in the power receiving unit and a decrease in output voltage due to movement of the moving body.

In particular, the switching unit is connected when the first power receiving unit or the second power receiving unit is located at or near a passive line section formed between adjacent separate sets of power supply lines, and It is preferable that the first power receiving unit and the second power receiving unit are shut off when located in the same set of power supply line sections.

By controlling the switching unit in this manner,
The moving body side power supply circuit of the non-contact power supply device of the present invention outputs a required voltage as a substantial voltage doubler power supply circuit when one power receiving unit is located at or near a non-feeding line section. When the second power receiving unit is present in the same set of power supply line sections, the current imbalance is eliminated as a substantial series power supply circuit. Therefore, regardless of the position of the moving body, the required voltage is output to the load on the moving body side, and unexpected heat generation in the power receiving unit is prevented. In addition, when the power receiving unit is located not only in the non-feeding line section but also in the vicinity thereof, the output voltage can be further stabilized by connecting the switching unit to form a double voltage power supply circuit.

Further, it is preferable that a first resistor connected in parallel with the first capacitor and a second resistor connected in parallel with the second capacitor are provided.

Since the resistors are connected in parallel to the respective capacitors, even when the switching unit is switched to the cutoff state, the voltage applied to both ends of the first capacitor and the second capacitor is equal to the first resistor. And the voltage is divided according to the resistance value of the second resistor. For this reason, it is possible to prevent an overvoltage from being applied to one of the capacitors exceeding the respective allowable voltages of the first capacitor and the second capacitor. When the switching unit is connected, the voltage generated by the first power receiving unit and the second power receiving unit is alternately applied to the first capacitor and the second capacitor regardless of the resistance value. No overvoltage exceeding the permissible voltage is applied.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the power supply circuit on the moving body side of the contactless power supply device of the present invention will be described below, and the present invention will be specifically described. FIG. 1 shows an overall view of a non-contact power supply device using a mobile power supply circuit according to the present invention. The non-contact power supply device includes a power supply line to which high-frequency AC power is supplied from a high-frequency power supply, and a moving body that operates by receiving AC power from the power supply line.

As the high frequency power supply, for example, a thyristor inverter type oscillator, a transistor inverter type oscillator, or the like can be used. A high-frequency power supply is provided for each set of power supply lines. As shown in FIG. 1, one feed line is folded back at the center to become two feed lines, and each feed line is kept parallel to a track rail of a moving body (not shown).
Is laid. In this embodiment, this state is referred to as a set of power supply lines. However, one set of power supply lines is not limited to this, and may form one annular loop, or may be configured with more than two parallel power supply lines. Therefore, the plurality of sets of power supply lines can take various forms depending on the type of the moving object and the moving route thereof.

The mobile unit includes a mobile unit-side power supply circuit according to the present invention, a control unit including a control circuit that operates by the DC power output from the power supply circuit, and a DC power received from the power supply circuit via an inverter. And a drive unit for supplying the AC motor and running the moving body. In addition, the control unit controls the driving speed of the moving body by controlling the driving unit,
It controls switching of a switching unit of a power supply circuit on the moving body described later.

As shown in FIG. 1, the mobile-side power supply circuit includes a power receiving section having a first power receiving section and a second power receiving section, a rectifying section for rectifying AC power received from the power receiving section, A first capacitor and a second capacitor for storing the rectified DC power.
An output unit including a capacitor, and a switching unit that switches connection or disconnection between a power receiving side intermediate point between the first power receiving unit and the second power receiving unit and a capacitor side intermediate point between the first capacitor and the second capacitor.

FIG. 2 shows a specific circuit configuration of the mobile-side power supply circuit. As shown in FIG. 3, both the first power receiving unit and the second power receiving unit constituting the power receiving unit have a core 11 having an E-shaped cross section.
And a coil 12 wound around a central projection of the core 11. The coil 12 is wound so as to interlink a magnetic flux generated by a pair of parallel power supply lines 1 and 2 extending in a non-contact state on both sides thereof. Therefore, when high-frequency AC power is supplied to the power supply lines 1 and 2, an AC electromotive force is generated in the coil 12 by electromagnetic induction, and the AC power is supplied from the power supply lines 1 and 2 to the coil 12 in a non-contact state. Power will be supplied. Both ends of the coil 12 are connected to the input terminals U1 and V1 of the first power receiving unit and the input terminals U2 and V2 of the second power receiving unit shown in FIG. In this embodiment, the input terminal V1 and the input terminal U2 are connected. The rectification unit next to the power reception unit includes four diodes D1 to D4, and forms a bridge rectification circuit. The input terminals of this bridge rectifier circuit are connected to the aforementioned input terminals U1 and V2, and the output terminals of the bridge rectifier circuit are connected to the first capacitor Ca and the second capacitor Cb of the next output unit.

The output section includes a first capacitor Ca and a second capacitor Cb connected in series, a first resistor Ra connected in parallel to the first capacitor Ca, and a second resistor Rb connected in parallel to the second capacitor Cb. One end of the first capacitor Ca (first resistor Ra) is connected to the positive output terminal P, and one end of the second capacitor Cb (second resistor Rb) is connected to the negative output terminal N. I have. Then, a predetermined output voltage Vout is output between both ends of the output terminal PN.

The switching unit includes a switch SW. One end of the switch SW is connected to the input terminal V1 of the first power receiving unit and the second terminal.
The other end of the switch SW is connected to a capacitor-side middle point Mc intermediate between the first capacitor Ca and the second capacitor Cb, while being connected to a power-receiving-side middle point Mi between the input end U2 of the power receiving unit. Have been. Accordingly, the connection / disconnection of the power receiving side intermediate point Mi and the capacitor side intermediate point Mc is switched by the intermittent operation of the switch SW, so that the circuit configuration of the moving body side power supply circuit can be changed. The turning on and off of the switch SW is controlled by the control unit, and the control unit turns on and off the switch SW based on a signal from a sensor of the detecting unit provided in the moving body shown in FIG. Specifically, when the sensor of the detection unit detects the parasitic line section, the control unit receives the signal and connects the switch SW (O
N) to switch the moving body side power supply circuit to a so-called double voltage power supply circuit. Conversely, if the sensor of the detection unit does not detect the parasitic line section, the control unit shuts off the switch SW (OF
F) In the state, the mobile body side power supply circuit is switched to a so-called series power supply circuit.

Next, the operation of the mobile power supply circuit will be described. When the switch SW is OFF, the moving body side power supply circuit operates as a series power supply circuit as described above. At this time, the first power receiving unit and the second
Since both the power receiving units are on the same set of power supply lines, AC power of the same phase is supplied to both power receiving units. Therefore, an AC voltage is generated between the input terminal U1 and the input terminal V2 of the power receiving unit, which is the sum of the voltage across the first power receiving unit and the voltage across the second power receiving unit. For example, 100 V AC between the input terminals of the first power receiving unit.
Occurs, and AC100V is generated between the input terminals of the second power receiving unit, and AC20V is applied between the input terminal U1 and the input terminal V2.
0V is generated. After this is subjected to full-wave rectification by the rectifier, it is smoothed by the first capacitor Ca and the second capacitor Cb of the output unit, and is output from the output terminal PN as a DC voltage.

By the way, generally, the time during which both power receiving units exist on the same set of power supply lines is longer than the time during which one power receiving unit exists in the non-feeding line section. That is, the switch S
It is longer when W is in the OFF state. In the moving body side power supply circuit of the present invention, the series power supply circuit is configured on the long time side to prevent imbalance of current, so that only one side of the power receiving unit does not generate excessive heat. Further, since the voltage applied to both ends of the first capacitor Ca and the second capacitor Cb is divided by the first resistor Ra and the second resistor Rb, it is possible to prevent an overvoltage from being applied to each capacitor. it can.

When the switch SW is ON, the moving body side power supply circuit operates as a voltage doubler power supply circuit as described above. In the mobile power supply circuit of the present invention, the operation when one of the power receiving units is in the non-feeding line section is particularly important. Therefore, an example in which the second power receiving unit is in the non-feeding line section will be described below. When the second power receiving unit is in the non-feeding line section, only the first power receiving unit receives supply of AC power from the power feeding line. When the first power receiving section outputs “positive voltage (U1> V1)”, the input terminal U1 → diode D1 → first capacitor Ca → capacitor-side intermediate point Mc → switch SW → power receiving-side intermediate point Mi → input terminal V1 and current Flows to charge the first capacitor Ca 2.

Conversely, when the first power receiving unit receives the negative voltage (U1 <V
1) ", the input terminal V1 → the power receiving side intermediate point Mi →
A current flows through the switch SW → the capacitor-side intermediate point Mc → the second capacitor Cb → the diode D2 → the input terminal U1, and the second capacitor Cb is charged. As described above, even when one of the power receiving units is in the non-feeding line section, both the first capacitor Ca and the second capacitor Cb are charged.
The output voltage Vout between the output terminals PN can be obtained almost the same output voltage Vout (maximum voltage) as when the switch SW is in the OFF state without being greatly reduced.

In order to always stabilize the operation of the moving body, it is preferable to prevent the output voltage from dropping as soon as possible. Therefore, it is preferable that the switch SW be turned on as soon as possible when the power receiving unit approaches the non-feeding line section. Note that even if the switch SW is turned on earlier, the time is short, so that there is no substantial problem even if a current imbalance occurs between the first power receiving unit and the second power receiving unit. Also, depending on the relationship between the mounting interval between the first power receiving unit and the second power receiving unit and the length of the non-feeding line section, the first power receiving unit and the second power receiving unit supply AC power from adjacent pairs of power feeding lines, respectively. It can happen. That is, the first power receiving unit and the second
It is conceivable that a phase difference occurs between the supplied AC power and the power receiving unit. However, since the first power receiving unit and the second power receiving unit alternately charge the first capacitor Ca and the second capacitor Cb, the output voltage Vout required for the stable operation of the moving body is maintained. Is done.

While the embodiment of the power supply circuit on the moving body side of the contactless power supply apparatus according to the present invention has been described above, the present invention is not limited to this, and for example, the following embodiment can be considered. In the above-described embodiment of the moving body side power supply circuit, the power receiving unit is 2
There are three cases, but three or more may be used.
The arbitrarily selected power receiving units may be the first power receiving unit and the second power receiving unit. This is the same for the first capacitor, the second capacitor, the first resistor, and the second resistor.

The diode used in the above embodiment,
Various types of capacitors, resistors, and the like can be used as long as they are within the allowable capacity according to the type of the non-contact power supply device.

As the switch, various types such as a relay switch and a semiconductor switch can be used. Further, it is not always necessary to intervene the control unit for switching the switch. Rather, if the switching can be performed directly based on the output signal of the detection unit without the intervention of the control unit, the malfunction can be more reliably prevented.

Further, the switching timing of the switch is determined by calculating the position of the moving body from a signal of a rotary encoder or the like as needed in addition to providing a dedicated detection sensor, and determining the relative position with respect to the non-feeding line section. You may do it. In addition, when the switch is in the OFF state, the moving body side power supply circuit is a series power supply circuit. Therefore, when one power receiving unit is inserted in the non-feeding line section, the output voltage starts to decrease. If the control unit detects the decrease in the output voltage and switches the switch SW to ON, it is not necessary to provide a separate sensor.

[0031]

According to the mobile power supply circuit of the non-contact power feeding device of the present invention, a required voltage can be output to the mobile body irrespective of the position of the power receiving unit, and the current flowing through each power receiving unit can be constantly increased. Unbalance can be prevented.

[Brief description of the drawings]

FIG. 1 is an overall view of a contactless power supply device according to the present invention.

FIG. 2 is a circuit diagram showing an embodiment of a mobile power supply circuit of the wireless power supply device according to the present invention.

FIG. 3 is an enlarged view of a power receiving unit of the mobile power supply circuit according to the present invention.

FIG. 4 is a circuit diagram showing a moving body side power supply circuit (series power supply circuit) of a conventional contactless power supply device.

FIG. 5 is a circuit diagram showing a moving body side power supply circuit (double voltage power supply circuit) of a conventional contactless power supply device.

[Explanation of symbols]

 Ca first capacitor Cb second capacitor Ra first resistor Rb second resistor SW switch (switching unit)

Continued on the front page (72) Inventor Isao Watanabe 2-1-1 Toyota-cho, Kariya-shi, Aichi F-term in Toyota Industries Corporation (reference) 5H006 AA00 BB00 CA07 CB01 CB04 CB09 CC08 5H105 AA20 BA01 CC02 CC19 DD10

Claims (3)

[Claims] A power receiving unit for receiving AC power by electromagnetic induction in a non-contact state from at least one of a plurality of power supply lines to which AC power is supplied, and converting the AC power received by the power receiving unit into DC power A rectifying unit for rectifying the power, and an output unit for outputting the DC power obtained from the rectifying unit to a load via a capacitor connected between the terminals; The power receiving unit includes at least two first power receiving units and a second power receiving unit connected in series, and the capacitor of the output unit includes a first capacitor and a second capacitor connected in series. A power receiving side intermediate point with the second power receiving unit, and a switching unit capable of switching connection or disconnection of a capacitor side intermediate point between the first capacitor and the second capacitor. contact Power supply circuit on the mobile side of the power supply device. 2. The switching unit is connected when the first power receiving unit or the second power receiving unit is located at or near a passive line section formed between adjacent separate sets of power supply lines. The mobile power supply circuit of the non-contact power feeding device according to claim 1, wherein the first power receiving unit and the second power receiving unit are cut off when located in the same set of power supply line sections. 3. The mobile-side power supply circuit according to claim 1, further comprising a first resistor connected in parallel with said first capacitor, and a second resistor connected in parallel with said second capacitor.