JP2002320343A - Non-contact power supply equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-contact power supply equipment which can make a load uniform within its capability to reduce a power receiving capacity, reduce dimensions of a power receiving part, reduce a ground power receiving equipment capacity, and extend a distance of a power supply section. SOLUTION: This non-contact power supply equipment supplies a power from a ground equipment to a carrier via a power supply line 10 through which a high frequency current flows, and a pickup coil 12 by electromagnetic induction in a non-contact manner. A power accumulating means 4, which is charged by the supplied power and supplies a power to a load 6 when a power consumed by the load 6 exceeds a specified value, is provided in the carrier.

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 system, and more particularly, to reducing a power receiving capacity by leveling a load within the capacity of the non-contact power supply system, downsizing a power receiving portion, and reducing a ground power supply system capacity. The present invention relates to a non-contact power supply facility capable of reducing the power consumption and increasing the power supply section length.

[0002]

2. Description of the Related Art For example, in a semiconductor manufacturing plant, an automatic guided vehicle is used to transport parts and the like in a clean environment. However, power is not supplied to a traveling vehicle of the automatic guided vehicle without generating dust. In order to do so, power is supplied in a non-contact manner.

[0003] This non-contact power supply equipment is equivalent to a transformer having low primary and secondary coupling, and the power supply viewed from the load is a power supply having a high internal impedance. Since the voltage drops sharply, a load such as a servomotor that performs current control according to a required torque irrespective of the power supply voltage needs a power supply capacity having a capacity larger than the power that can be consumed by the load. For this reason, the power receiving capacity of the non-contact power supply equipment should be equal to or greater than the sum of the maximum power of the traveling servomotor and the transfer servomotor, and the sum of the power constantly consumed by the control device and various sensors, plus the drive margin. Selected.

[0004]

For example, in a semiconductor factory or a liquid crystal manufacturing factory, the transfer within a process or between processes is a characteristic of a transfer facility, in which power consumption at the time of acceleration of a transfer vehicle and a transfer object are transferred by a transfer device. The power at the time of rising and falling and the power at the time of prominence are higher than the average power. This transfer equipment repeats a series of operations such as loading and unloading and moving in a cycle of about 2 minutes, and the ratio of the average power consumed by the load to the instantaneous maximum power in one cycle is 1.5 to 2 times. There is a degree of difference. For this reason, when power is always supplied to the load using conventional wireless power transfer equipment, it is necessary to ensure that the installed capacity of the receiving part operates up to the maximum current consumed by the load, and that the installed capacity is equal to or greater than the maximum power of the load. Is required.

The present invention has been made in view of the above-mentioned problems of the conventional non-contact power supply equipment, to reduce the power reception capacity by leveling the load within the capacity of the non-contact power supply equipment, to reduce the size of the power reception part, and to realize the ground power supply equipment. An object of the present invention is to provide a non-contact power supply equipment capable of reducing the capacity and increasing the length of a power supply section.

[0006]

In order to achieve the above object, a non-contact power supply equipment of the present invention uses a power supply line through which a high-frequency current flows and a pickup coil to electromagnetically induce electric power from a ground equipment to a carrier without contact. In the non-contact power supply equipment configured to supply power, the carrier is provided with power storage means for charging the supplied power and supplying power to the load when the power consumed by the load exceeds a specified value. It is characterized by the following.

This non-contact power supply equipment is provided with a power storage means for charging the supplied power and supplying the power to the load when the power consumed by the load exceeds a specified value. , Leveling the load within the capacity of the contactless power supply can reduce the receiving capacity,
It is possible to reduce the size of the power receiving coil occupying a large volume and weight in the power supply equipment, reduce the ground power supply equipment capacity, or increase the power supply section length for the same ground power capacity.

In this case, a capacitor is used as a power storage member of the power storage means, and charging of the capacitor is performed by:
It can be performed at a constant current or less within the range of the power receiving capacity of the non-contact power supply equipment.

As a result, charging suitable for the energy density and internal resistance of the capacitor can be performed.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a contactless power supply system according to an embodiment of the present invention.

1 to 6 show an embodiment of the non-contact power supply equipment of the present invention. The non-contact power supply equipment is laid along a traveling path (not shown), and is a primary power supply line 1 through which a high-frequency current flows.
0, and a power receiving circuit 1 that receives power supply by electromagnetic induction via a pickup coil 12 provided on a carrier (not shown) side. This non-contact power supply equipment is shown in FIG.
As shown in FIG. 1, the primary feeder 10 is laid in a state where the primary feeder 10 is supported by the support body 8, and the pickup coil 12 in which the secondary winding 11 is wound around the E-type ferrite core 9 is placed on the primary feeder 10. The magnetic field of the high-frequency current flowing through the secondary power supply line 10 is transmitted to the secondary winding 11 by electromagnetic induction. The AC output of the power receiving circuit 1 is converted to DC by the rectifying / smoothing circuit 2.

The power receiving circuit 1 includes an AC power supply such as a high-frequency inverter for supplying a current to the primary power supply line 10, an internal resistance determined by the inductance of the secondary pickup coil 12 and the primary and secondary coupling, and a resonance circuit including a resonance capacitor. And receive power. In this embodiment, as shown in FIG. 3, the power receiving circuit 1 shows an example in which the voltage of the resonance circuit is suppressed to be constant by the saturable reactor. However, the present invention is not limited to this, and the load power is small. At this time, a low voltage device that keeps the resonance voltage constant by separating the capacitance of the resonance capacitor from the circuit by the switching element may be used.

As shown in FIG. 1, this non-contact power supply equipment supplies a DC output voltage to a load 6 from a rectifying / smoothing circuit 2 downstream of a power receiving circuit 1. in this case,
In addition to a circuit for supplying power to the load 6, a power storage means (circuit) is provided in parallel. The power storage means uses an electric double-layer capacitor 4 as a large-capacity power storage member (capacitor). The electric double-layer capacitor 4 uses a plurality of constant-voltage capacitors having a rated voltage of about 2 V in series connection. I do. The electric double-layer capacitor 4 is charged by the constant current charging circuit 3, and the electric charge stored in the electric double-layer capacitor 4 is boost-converted to a DC voltage by the boost converter 5. The power storage means includes a rectifying / smoothing circuit 2 and a load 6.
It is also possible to supply all of the load power from the power storage means in the middle of the above, but in that case, the capacity of the electric double-layer capacitor 4 for storing power becomes large, which leads to an increase in device cost and device weight.

Next, the operation of the non-contact power supply equipment of this embodiment will be described.

The power consumption of the load 6 can be roughly divided into the following three in the case of a transfer device.

P ₁ : traveling drive power This is the power required to drive the vehicle body of the carrier, and consumes the most power during acceleration. During traveling at a constant speed, if the traveling resistance of the wheels is small, the power consumption is determined by the product of the traveling resistance on the road surface, the traveling speed, and the weight of the vehicle body. While the carrier vehicle is decelerating, power regeneration occurs. In this embodiment, the regenerative power can be used to charge the electric double-layer capacitor 4. When a general-purpose servomotor is used, it can be discharged by a resistor and converted into heat.

P ₂ : transfer device drive power This is the power required for loading and unloading the load from the carrier, and performs horizontal movement and vertical (elevation) movement. The maximum power is consumed by moving in the up and down directions. Regeneration of electric power occurs as in traveling.

P ₃ : Power steadily consumed by sensors and control devices Power steadily consumed by sensors and various display / control devices, which is several percent to 10% relative to travel driving and transfer driving.
Consumes around the power.

Therefore, the power P consumed by the load 6
_L is P _L = P ₁ + P ₂ + P ₃ . FIG. 4 shows the power consumption of the load 6. In this case, 13 plots P _L, 14 are plots of P _1, 15
Indicates a plot of P ₂ and 16 indicates a plot of P ₃ .
A plot of the power receiving capacity of the non-contact power feeding is set to 17, and when the power consumption is larger than this, the electric charge stored in the electric double layer capacitor 4 is discharged.

Since the load 6 is connected to a DC circuit,
The power P _{L of the} load 6 is the product of the voltage E of the rectifying / smoothing circuit 2 and the load current I. P _L = EI _L Here, when E = 150 V and a constant voltage, P _L = 1
50I _L next to the current need only monitor the I _L, without evaluating the product of current and voltage, thereby simplifying the control circuitry.

On the other hand, the charging condition of the electric double layer capacitor 4 is performed under the following constraint conditions. (1) The load power P _L is set at a plot 17 or lower that limits the capacity of the received power. Assuming that the capacity limit is R, P _L <R

(2) The electric double layer capacitor 4 is charged at a constant current or less. Limit value I of charging current
_{If LIM} , the charging current I _C is I _C <I _LIM and I _C
I _C = R−I _L E / E This constraint mainly depends on the energy density and the internal resistance of the electric double layer capacitor 4.

(3) An electric double layer capacitor 4 is connected in series, and a voltage limiting circuit is provided in parallel with each capacitor. When the voltage of the capacitor rises above a certain voltage, a constant voltage diode that bypasses the charging voltage, or Provide a corresponding circuit. _Assuming that the operating voltage of this bypass circuit is E _VZ and the number n of capacitors connected in series, the voltage V _CAP applied across the electric double-layer capacitor 4 during charging is limited to V _CAP <nE _VZ . This constraint condition is that when a voltage higher than this is applied excessively or constantly, the electric double layer of the electric double layer capacitor 4 is broken, the electrolytic solution is electrolyzed, gas is generated, and the life is shortened. When the voltage of the electric double layer capacitor 4 reaches the above condition, it indicates that the charging of the electric double layer capacitor 4 has been completed. At this time, the energy Q stored in the electric double layer capacitor is
When the capacitance of the layered capacitor 4 is C, the Q = nCE _VZ ^2/2.

Next, the operation of boost converter 5 for discharging electric double layer capacitor 4 will be described. The energy Q stored in the electric double-layer capacitor 4 has the value described above. However, in order to discharge the charged energy efficiently, it is necessary to lower the discharge end voltage. For example,
When the discharge end voltage E _S of the electric double layer capacitor 4 is discharged to 50% of E _VZ , 75% of the stored energy
When the discharge is performed up to 30%, the discharge can be performed up to 91% of the stored energy. The electric double layer capacitor 4 can be used alone as E _VZ
= 2V, which is as low as about 2V, it is necessary to select the number of connections n so that the boost converter 5 operates efficiently even when the discharge end voltage of the capacitors connected in series is discharged to 30%. For example, if the operating voltage of the boost converter 5 is 10
Even if operation is possible up to V, 0.3 nE _VZ > 10 n> 17.

The basic circuit of the boost converter 5 can be realized by the circuit shown in FIG. Inductor 18, diode 19, switching element 20, and capacitor 21
Is well known, and the voltage step-up ratio is determined by the ratio of the operation time T _on of the switching element 20 to the switching period T. When the boost ratio is increased, the time T for storing energy in the inductor 18 is obtained.
_On indicates that the capacitor 2 is not charged because the capacitor 21 is not charged.
The ripple current flowing in 1 increases as the step-up ratio increases. Therefore, the series number n of the electric double-layer capacitor 4
Is to reduce the output voltage E of the rectifying / smoothing circuit 2 by n so as to reduce the ripple of the boost converter 5 more than the above-mentioned constraint.
A reasonable design is to make E _VZ close and to maximize the number of series in a range where the cost of the bypass circuit connected in parallel to each capacitor is acceptable.

The output voltage E of the rectifying / smoothing circuit 2 is monitored by the load current detecting means 7 for the operation start voltage of the boost converter 5. If this voltage falls below a prescribed value due to an increase in the load, this voltage is output. Is controlled so as to be close to the specified voltage, power that cannot be supplied by the pickup coil 12 of the power receiving circuit 1 can be supplied from the electric double-layer capacitor 4. As a result, as shown in FIG.
, The electric power 22 and the electric power 23 for charging of the electric double-layer capacitor 4 corresponding to the operation of. The load current detecting means 7 may be a DC current detector such as a shunt resistor, a Hall CT, or the like. By calculating the product of the A and the observed value, the power consumed by the load can be obtained.

In this case, the charge and discharge of the electric double-layer capacitor 4 must be balanced in any operation cycle of the carrier. If the electric double layer capacitor 4 reaches the discharge end voltage during one cycle of operation, the carrier cannot operate. In order to avoid this, the power receiving capacity of the pickup coil 12 is set to be equal to or more than the average power of the operation cycle, and an operation margin is secured. As another method, when the discharge state of the electric double layer capacitor 4 is monitored and it is expected that the discharge end voltage will be reached if the operation is continued as it is, the operating speed of the machine is temporarily reduced, or the acceleration operation is performed. If, the acceleration is stopped and the operation is shifted to the constant speed operation to eliminate the power consumption, so that the termination of the discharge of the electric double layer capacitor 4 can be avoided.

[0028]

According to the non-contact power supply equipment of the present invention, the electric power is supplied to the carrier, and the electric power is supplied to the load when the electric power consumed by the load exceeds a specified value. By providing the means, it is possible to reduce the receiving capacity by leveling the load within the capacity of the non-contact power supply equipment,
As a result, it is possible to reduce the size of the power receiving coil that occupies a large volume and weight in the power supply equipment, reduce the ground power supply equipment capacity, or increase the power supply section length for the same ground equipment capacity.

Further, by using a capacitor as a power storage member of the power storage means and charging the capacitor at a constant current or less within the range of the power receiving capacity of the non-contact power supply equipment, it is suitable for the energy density and internal resistance of the capacitor. Can be charged.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of a non-contact power supply equipment of the present invention.

FIG. 2 is a cross-sectional view showing the wireless power supply equipment of the embodiment.

FIG. 3 is a circuit diagram illustrating an example of a power receiving circuit.

FIG. 4 is a graph showing power consumption during operation.

FIG. 5 is a graph showing charge / discharge power of a capacitor corresponding to the operation of FIG.

FIG. 6 is a circuit diagram illustrating an example of a boost converter.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 power receiving circuit 2 rectifying / smoothing circuit 3 constant current charging circuit 4 electric double layer capacitor 5 boost converter 6 load 7 load current detecting means 8 support 9 core 10 power supply line 11 secondary winding 12 pickup coil

Claims (2)

[Claims] 1. A non-contact power supply system in which power is supplied from a ground facility to a carrier in a non-contact manner by electromagnetic induction through a power supply line through which a high-frequency current flows and a pickup coil. And a power storage means for supplying power to the load when the power consumed by the load exceeds a specified value. 2. A non-contact type battery according to claim 1, wherein a capacitor is used as a power storage member of the power storage means, and the capacitor is charged at a constant current or less within a range of the power receiving capacity of the non-contact power supply equipment. Power supply equipment.