JP5528089B2 - Power supply for contactless power supply equipment - Google Patents

Description

  The present invention relates to a power supply apparatus that supplies a high-frequency current to an induction line disposed along a moving path in a non-contact power feeding facility that supplies power to a moving body that moves along a certain moving path in a contactless manner.

An example of the conventional contactless power supply facility and its power supply device is disclosed in Patent Document 1.
In the non-contact power supply facility disclosed in Patent Document 1, the impedance at a predetermined frequency is a predetermined capacitive impedance continuously along the movement path of a transport carriage having a load (traveling motor) whose power consumption varies. A power supply device is provided that arranges the adjusted induction line and supplies a high-frequency current of the predetermined frequency to the induction line.

  The power supply device includes a rectifier that converts an alternating current of an alternating-current power supply whose alternating voltage fluctuates into a direct-current voltage and current, a step-up / step-down circuit that steps up and down the direct-current voltage according to a load on the induction line, and a step-up / down circuit. An inverter that converts the direct current of the direct current voltage into a constant alternating current of the predetermined frequency by a plurality of switching elements respectively driven by a rectangular wave signal (pulse signal) and outputs the constant alternating current to the induction line, Reduces the DC voltage when the load on the induction line is less than a preset value in a range of 15 to 20% of the total load, and when the load on the induction line is greater than or equal to the set value, The inverter is configured to boost the DC voltage, and the inverter always performs PWM control (pulse width control of the rectangular wave signal) according to the load on the moving path and outputs it to the induction line It is configured to control the flow constant.

  With such a configuration, a high-frequency constant current having a predetermined frequency is supplied from the power supply device to the induction line, and the moving body supplies power to the load by the electromotive force induced in the power receiving coil by the induction line. In addition, since the impedance of the induction line at a predetermined frequency is adjusted to a predetermined capacitive impedance, fluctuations in the current flowing through the induction line are suppressed even when the load on the moving body fluctuates.

  Also, by controlling the DC voltage to be low when the load on the induction line is lighter than the set value by the step-up / down circuit, and to control the DC voltage to be high when the load on the induction line is heavier than the set value, the current flowing through the induction line The switching element is within a range (a constant current control range; for example, 25% to 75%) of a rectangular wave signal energization ratio (duty ratio; a ratio of time during which current is actually energized in one cycle). A constant current control is realized in which an energization rate for driving is entered, there is a margin in the control of the energization rate, and the response is fast.

  Furthermore, by setting the set value of the load on the induction line for switching between the step-down control and the step-up control to the range of 15 to 20% of the total load, that is, the side where the load is light, the voltage is increased in the range of 80 to 85% of the load Therefore, it is possible to prevent power shortage due to an increase in load.

JP 2009-101484 A

  However, the current flowing through the induction line by the inverter is always controlled to a constant current, and a high DC voltage boosted in the range of 80 to 85% of the normal load is input to the inverter. There is a problem that a large power loss usually occurs because the value is obtained when the constant current is switched with respect to the input voltage.

  For example, the constant current is controlled to 160A, and the output voltage of the rectifier is applied to the inverter as it is, for example, DC280V (= AC200V × √2; when the voltage of the AC power supply supplied to the power supply device is 200V) Then, the power loss is a value obtained by switching 160 A with respect to DC 280V.

In view of this, the present invention can suppress the energization rate of the PWM control of the inverter to a marginal range, can perform stable constant current control of the induction line, and can reduce power loss in the inverter. it is intended to provide a power supply generation facilities.

In order to achieve the above-described object, the invention according to claim 1 of the present invention is arranged such that an induction line is disposed along a moving path of a moving body, and a receiving coil is disposed on the moving body so as to face the induction line. In the contactless power supply facility that supplies power to a load whose power consumption fluctuates from the electromotive force induced in the power receiving coil, the mobile unit is a power supply device that supplies a constant alternating current of a predetermined frequency to the induction line. And
A rectifier circuit that converts an alternating current of an alternating current power source into a direct current, a step-down circuit that steps down a direct current voltage converted by the rectifier circuit, and a current of a direct current voltage that is stepped down by the step-down circuit are respectively represented by pulse signals. An inverter that converts the alternating current of the predetermined frequency into a constant alternating current by a plurality of driven switching elements and outputs the constant alternating current to the induction line, and the step-down circuit corrects the direct-current voltage to be low in accordance with a decrease in the inverter energization rate. Then, the DC voltage is corrected to be higher in accordance with the increase in the inverter energization rate, and the switching element of the inverter is output to the induction line with an average energization rate of 50% or more with respect to the half cycle of the predetermined frequency. The DC voltage is controlled according to the load of the induction line so that the AC current to be controlled can be controlled to the constant AC current. Than is.

  In the power supply device of the non-contact power supply facility disclosed in Patent Document 1, the energization rate of the pulse signal for driving the switching element is in the range of the energization rate in which the current flowing through the induction line can be controlled to be constant. A constant current control is realized that has a quick response and a fast response, and the range of the energization rate is, for example, 25% to 75%. The energization rate is small when the load is small and large when the load is large. Is done. However, as described above, the power loss in the inverter becomes a value when the constant current is switched with respect to the input voltage of the inverter. Now, as shown in FIG. 7, in the voltage waveform a, if the energization rate is increased even when the load is small (in FIG. 7, the energization rate is changed from 35% to 70%), the current increases from a constant current and flows. Therefore, when the input voltage to the inverter is lowered as shown in the voltage waveform b (in FIG. 7, when the input voltage is lowered from DC 280 V to DC 140 V), the current returns to a constant current. Since the current is constantly controlled and the voltage decreases, the power loss decreases as the voltage decreases. The level of switching noise also decreases as the voltage decreases.

According to the above configuration, in the step-down circuit, the load of the induction line, that is, the DC voltage converted by the rectifier circuit is stepped down according to the conduction ratio of the switching element of the inverter that changes according to the current flowing through the induction line, At this time, in the inverter, the average energization ratio is 50% or more for a half cycle of the predetermined frequency, each of the plurality of switching elements is driven, the current flowing through the induction line is controlled to a constant alternating current, and is converted to the predetermined frequency. Output to the induction line. Thus, the current and frequency flowing through the induction line are controlled to be constant by the inverter. In the current flowing through the induction line is constant, and by the input voltage of the inverter can be controlled according to the load, reduces the power loss in the inverter, decreases by the amount that the level of noise at the switching of the inverter is also the voltage drops.

  The invention according to claim 2 is the invention according to claim 1, wherein the range of the energization ratio is set to 65% to 75%, and the step-down circuit has an energization ratio of the pulse signal of 65%. The DC voltage corresponding to the load is corrected to be low when the voltage is less than%, and the DC voltage corresponding to the load is corrected to be high when the energization rate of the pulse signal exceeds 75%. is there.

  According to the above configuration, the pulse signal is controlled in the range of the energization rate of 65 to 75%, that is, at a high energization rate. The voltage is stepped down and a constant current is supplied to the induction line.

  The contactless power supply equipment of the present invention can reduce the power loss in the inverter by controlling the current flowing through the induction line to be constant and reducing the input voltage of the inverter according to the load by the step-down circuit. The noise level can be reduced.

It is a circuit block diagram of the non-contact electric power feeding equipment provided with the power supply device of the non-contact electric power feeding equipment in Embodiment 1 of this invention. It is explanatory drawing regarding the step-down controller of the step-down circuit of the same power supply device, (a) is a block diagram of the step-down controller, (b) is a block diagram of a voltage ratio calculation unit of the step-down controller, (c) is an energization of the inverter by the step-down controller It is a characteristic figure of a rate and the output voltage of a step-down circuit. It is operation | movement explanatory drawing of the pressure | voltage fall circuit of the power supply device, (a) is a figure which shows the flow of the electric current at the time of pressure | voltage fall, (b) is a figure which shows the characteristic of the pulse of a switching element, and a coil current. It is a circuit block diagram of the non-contact electric power feeding equipment provided with the power supply device of the non-contact electric power feeding equipment in Embodiment 2 of this invention. It is a block diagram of the step-down controller of the step-down circuit of the same power supply device. It is a circuit block diagram of the pressure | voltage fall circuit of the power supply device of the non-contact electric power supply equipment in other forms of implementation of this invention. It is explanatory drawing of the voltage applied to the high frequency transformer (high frequency transformer 30A of FIG. 1) of the non-contact electric power supply equipment in case a load is small.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Embodiment 1]
FIG. 1 is a circuit configuration diagram of a contactless power supply facility including a power supply device for the contactless power supply facility according to Embodiment 1 of the present invention.

  In FIG. 1, reference numeral 11 denotes an induction line that is continuously laid (arranged) along a traveling rail (an example of a movement path; not shown) of a transport carriage (an example of a moving body) 12. The capacitor 14 is connected in series, and the variable inductor 15 that adjusts the inductance value of the entire induction line 11 is connected in series. The variable inductor 15 is connected when the length of the induction line 11 (line length) does not satisfy a predetermined length, that is, when the inductance value of the induction line 11 does not reach a predetermined inductance value. In addition, a plurality of transport carts 12 travel on the traveling rail, and power is supplied to the plurality of transport carts 12 from the guide line 11.

  By adjusting the inductance L of the variable inductor 15 and the capacitance C of the capacitor 14, the impedance of the predetermined frequency f (for example, 10 kHz) by the induction line 11 and the capacitor 14 and the variable inductor 15 connected in series (impedance of the entire induction line) Is adjusted (set) to a predetermined capacitive impedance.

  In addition, a pick-up coil (a power receiving coil facing the induction line 11) 21 is installed in the transporting carriage 12. ing. The pickup coil 21 is formed, for example, by winding a litz wire (both not shown) around a central convex portion of ferrite having an E-shaped cross section so that the induction line 11 is located at the center of both concave portions. Adjusted and fixed. Then, a power receiving unit 22 is connected to the pickup coil 21, the traveling motor 18 is connected to the power receiving unit 22 via an inverter 23, and the traveling motor is generated by an electromotive force induced in the pickup coil (power receiving coil) 21. Power is supplied to 18.

  The power receiving unit 22 is connected in parallel to the pickup coil 21 and a resonance capacitor 24 constituting a resonance circuit that resonates with the frequency of the pickup coil 21 and the induction line 11, and a rectifier 25 in parallel with the resonance capacitor 24 of the resonance circuit. , An inductor 26A is connected to the output side of the rectifier 25, an output capacitor 28 is connected in parallel with the inverter 23 corresponding to the output load, and a diode 26B is connected between the inductor 26A and the output capacitor 28, Further, an output voltage control switching element 27 is provided in parallel with the resonant capacitor 24 between the inductor 26A and the diode 26B, and the output voltage control switching element 27 is subjected to PWM control so that the voltage of the output capacitor 28 is constant. A controller 29 is provided.

This configuration of the power receiving unit 22, the voltage of the resonance capacitor 24 is rectified by a rectifier 25, a DC voltage is generated by the filter is multiplied by the inductor 26 A and the diode 26 B. The output controller 29 monitors this DC voltage (the voltage of the output capacitor 28) and compares it with a reference voltage. When the load power is smaller than the maximum power that can be output from the pickup coil 21, the voltage of the output capacitor 28 increases. Therefore, the output controller 29 increases the energization rate of the switching element 27 and lengthens the time that the pickup coil 21 is short-circuited. To do. Therefore, the power transferred from the pickup coil 21 is substantially close to zero, and therefore the DC voltage of the output capacitor 28 is reduced. The short circuit output capacitor 28 is prevented by this time the diode 26 B. Then, when the DC voltage of the output capacitor 28 decreases to a reference voltage or lower, or when the output load increases and the DC voltage of the output capacitor 28 decreases to a reference voltage or lower, the output controller 29 decreases the energization rate of the switching element 27. Thus, the time during which the pickup coil 21 is short-circuited is shortened, and the time during which the output capacitor 28 is energized is lengthened. Therefore, the DC voltage of the output capacitor 28 increases. By these actions, the DC voltage of the output capacitor 28 is maintained at the reference voltage.

  In addition, a power supply device 31 that supplies a constant high-frequency current (constant alternating current) of the predetermined frequency f (for example, 10 kHz) is connected to the induction line 11 via a high-frequency transformer 30A. The high frequency transformer 30A is interposed between the induction line 11 and the power supply device 31. For example, the output voltage is set to 2 so that the output voltage can be increased when the distance (length) of the induction line 11 is long. It is installed so that it can be doubled. In addition, a current transformer (CT) 30 </ b> B for measuring a current value flowing through the induction line 11 is installed in the induction line 11.

  An AC power supply 32 that supplies power to the power supply device 31 is connected to the power supply device 31. The AC power supply 32 is a power supply in which the AC voltage varies greatly. For example, the AC voltage varies by + 10% to −10% with respect to the rated voltage.

  The power supply device 31 converts the alternating current of the alternating current power supply 32 whose alternating voltage fluctuates into a direct current, and the direct current is converted into a predetermined frequency f by a plurality of switching elements respectively driven by a rectangular wave signal (pulse signal). A rectifier (full-wave rectifier) 33 that converts the alternating current of the alternating current power source 32 into a direct current, and a start / stop circuit 34. The step-down circuit 35 steps down the voltage rectified by the rectifier 33, that is, the direct-current voltage, and the inverter 36.

  The start / stop circuit 34 includes an inrush resistor 41 and a coil (reactor) 42 connected in series between the rectifier 33 and the step-down circuit 35, an activation conductor 43 that short-circuits the inrush resistor 41, an inrush resistor 41, and A discharge resistor 44 and a stop conductor 45 are connected in series between the connection point of the coil 42 and the negative output terminal of the rectifier 33. At the time of start-up, the start conductor 43 is in an open state, the inrush current is suppressed, and after a predetermined time, the start conductor 43 is closed and the inrush resistor 41 is short-circuited. Further, the stop conductor 45 is in an open state during operation, and is closed when stopped, and the electric charge accumulated in the power supply device 31 is consumed by the discharge resistor 44.

  The step-down circuit 35 includes an input capacitor 51 connected in parallel to the output of the start / stop circuit 34, a step-down switching element 52 and a coil 53 connected in series between the start / stop circuit 34 and the inverter 36. The cathode is connected to the connection point between the step-down switching element 52 and the coil 53, the anode is connected to the negative output terminal of the rectifier 33, the end of the coil 53 on the inverter 36 side, and the negative output of the rectifier 33. An output capacitor 57 connected between the terminals and a step-down controller 58 (details will be described later) composed of a CPU for pulse-controlling the step-down switching element 52.

  The inverter 36 drives the switching element 61 assembled in a full bridge and the switching element 61 by a rectangular wave signal (pulse signal), respectively, converts a direct current into a constant alternating current having a predetermined frequency f, and converts the direct current into the induction line 11. It is composed of a current control controller 62 composed of a CPU that feeds power as an output current. The direct current is converted into a constant alternating current of a predetermined frequency f by a switching element 61 that is driven by a rectangular wave signal to the induction line 11. Power is being supplied. The current controller 62 measures the current value of the induction line 11 by the input of the current transformer (CT) 30B, and the measured current value of the induction line 11 is a constant AC current set in advance. The pulse width of the pulse signal for driving the switching element 61 (a half cycle energization rate of the predetermined frequency f) is obtained so as to satisfy (feedback control of the current value of the induction line 11), and the switching element 61 is driven. . Further, the current controller 62 outputs the drive start signal of the inverter 36 and the energization rate of the pulse signal of the driving switching element 61 (the energization rate for a half cycle of the predetermined frequency f) to the step-down controller 58.

  The step-down controller 58 is thus supplied with the drive start signal of the inverter 36 and the energization rate (inverter energization rate) of the switching element 61 from the inverter 36 (current control controller 62).

  The step-down circuit 35 includes a switching element of the inverter 36 when the step-down switching element 52 is continuously on, that is, in a rectified state without step-down, and when the load of the induction line 11 is 100%, that is, the maximum load. A DC voltage (corresponding to a rated voltage) that can be controlled to the constant alternating current is obtained from the rectifier 33 when the 61 pulse signal is an average of 50% or more, for example 70%, of the inverter energization ratio for a half cycle of the predetermined frequency f. Have been entered.

  The step-down controller 58 is set with 65% to 75% as the range of the inverter energization rate. The 65% is an example in which the average of the energization rate is 50% or more with respect to a half cycle of the predetermined frequency f, the 70% is the target energization rate, and the 75% is an energization with a margin in the upper width. It is an example of the rate.

  With this step-down controller 58, the DC voltage output from the step-down circuit 35 is such that the switching element 61 of the inverter 36 has an inverter energization rate of 70%, and the alternating current output to the induction line 11 can be controlled to the constant alternating current. In addition, it is controlled according to the load of the induction line 11. The configuration of the step-down controller 58 will be described in detail.

As shown in FIG. 2, the step-down controller 58 includes a correction voltage forming unit 83, a voltage rate calculation unit 85, an energization rate calculation unit 86, and a pulse drive unit 87.
The correction voltage forming unit 83 is driven at a speed (for example, 1 ms) slower than the speed (for example, 1 μs) at which the inverter 36 is driven, and is input to the switching element 61 of the inverter 36 that is input every 1 ms. When the current supply rate (inverter current supply rate) is confirmed and the inverter current supply rate is lower than 65%, a negative correction voltage rate (%) for correcting the target (output) DC voltage of the step-down circuit 35 to be low in accordance with the decrease in the inverter current supply rate. ) (Ratio of the voltage to be corrected to the rated voltage) is output to the voltage ratio calculation unit 85 , and when the inverter current ratio becomes higher than 75%, the target DC voltage is corrected to be higher as the inverter current ratio increases. The corrected voltage rate is output to the voltage rate calculation unit 85 . The upper limit value α of the correction voltage rate of the correction voltage forming unit 83 is set so as to pull back the inverter energization rate within 75% according to the load of the induction line 11, and the lower limit value β of the correction voltage rate is In accordance with the load of 11, the inverter energization rate is set to 65% or more.

  Further, as shown in FIG. 2B, the voltage ratio calculation unit 85 is provided with a relay (RY) that is driven (excited) by the input of the drive start signal of the inverter 36, and until the inverter 36 is driven. , 100% of the voltage rate (no step-down) is output to the energization rate calculator 86, and when the inverter 36 is driven, the speed (for example, 1 ms) that is slower than the speed (for example, 1 μs) at which the inverter 36 is driven. ), For example, every 1 ms, the correction voltage rate (%) input from the correction voltage forming unit 83 is added to the current output voltage rate (target voltage rate) to obtain a new voltage rate (target voltage rate). , Output to the energization rate calculator 86.

The energization rate calculation unit 86 obtains the energization rate (step-down circuit energization rate) of the step-down switching element 52 from the voltage rate input from the voltage rate calculation unit 85 (details will be described later) and outputs it to the pulse drive unit 87.

The pulse driving unit 87 performs PWM control of the step-down switching element 52 based on the energization rate obtained by the energization rate calculation unit 86 (performs step-down control).
The operation of the above-described configuration of the step-down controller 58 will be described.

  In the correction voltage forming unit 83, for example, every 1 ms, when the input inverter energization rate of the inverter 36 falls below 65%, a negative correction voltage rate is formed according to the inverter energization rate, and the inverter energization rate is 75. If it exceeds%, a positive correction voltage rate is formed in accordance with the inverter energization rate. Subsequently, the voltage rate calculation unit 85 outputs a voltage rate of 100% (no step-down) until the inverter 36 is driven. When the inverter 36 is driven, for example, every 1 ms, the correction voltage rate formed in the correction voltage forming unit 83 is added to obtain and output the voltage rate (target voltage rate), and then the energization rate calculating unit 86, the voltage step-down circuit energization rate of the step-down switching element 52 is obtained from this voltage rate. Quenching element 52 is PWM controlled (step-down control is executed).

The operation of the step-down circuit 35 will be described with reference to FIG.
In FIG. 3, Vin is an input voltage of the step-down circuit 35, Vo is an output voltage of the step-down circuit 35, I is a coil current flowing through the coil 53, Imin is a minimum current (normal state) of the coil 53, Io is an output current, and L is The inductance of the coil 53, Ton is the switching ON time of the step-down switching element 52, Toff is the switching OFF time of the step-down switching element 52, and the ripple current is the ripple current of the coil 53.

  When the step-down switching element 52 is turned on by the step-down controller 58, the coil 53 is excited and the output capacitor 57 is charged by the current input from the rectifier 33, as indicated by the broken arrow, and the output current Io is As shown by the solid arrow, the output capacitor 57 is discharged, and the coil current I increases as shown in FIG.

  When the step-down switching element 52 is turned off by the step-down controller 58, the output capacitor 57 is charged by releasing the excitation energy of the coil 53, and the output current Io is represented by the solid line arrow, as shown by the one-dot chain line arrow. As shown, the output capacitor 57 is discharged, and the coil current I decreases as shown in FIG.

At this time, the output voltage Vo is
Vo = {Ton / (Ton + Toff)} × Vin (1)
It can be found that the voltage is stepped down and that the step-down is performed as the switching ON time Ton of the step-down switching element 52 is reduced. The minimum current Imin and ripple current of the coil 53 are
Imin = Io− (Vo × Toff / 2L),
Ripple current = Vo x Toff / L
Is required.

  Therefore, when the voltage ratio (= Vo / Vin) is obtained, the energization rate calculating unit 86 calculates the switching ON time Ton of the step-down switching element 52, that is, the energization rate (the step-down circuit energization rate) by the above equation (1). ). The time (Ton + Toff) can be set in advance.

"Action"
The operation of the non-contact power supply facility will be described. When the power supply device 31 is turned on, the load on the induction line 11 is the minimum load. When the AC power supply 32 is connected to the power supply device 31, the start conductor 43 is opened and the stop conductor 45 is closed. In addition, the AC voltage of the AC power supply 32 connected to the power supply device 31 has a rating of AC200V and varies within a range of AC180V to 242V. In the initial state, it is assumed that the inverter energization rate of the inverter 36 is set to 70%.

  When the AC power supply 32 is connected to the power supply device 31, the AC current is converted into a DC current by the rectifier 33 and output to the start / stop circuit 34. At this time, since the start conductor 43 is opened and the stop conductor 45 is closed, the inrush current at the time of activation is suppressed (limited) by the inrush resistor 41 and consumed by the discharge resistor 44. After a predetermined time, the starting conductor 43 is closed, the inrush resistor 41 is short-circuited, and then the stop conductor 45 is opened, and a stable DC current with the inrush current eliminated is output to the step-down circuit 35. At this time, the DC voltage after rectification by the rectifier 33 varies to DC240V when AC180V, DC270V when AC200V, and DC330V when AC242V.

  Until the inverter 36 is driven, the voltage ratio of the step-down circuit 35 is 100% (no step-down), and the step-down switching element 52 of the step-down circuit 35 is continuously turned on, that is, rectified, and output. The capacitor 57 is charged.

  Subsequently, when the inverter 36 is driven, the current controller 62 performs PWM control of the switching element 61 while feeding back the current value of the induction line 11, and controls the current flowing through the induction line 11 to a constant alternating current. Then, it is converted to a predetermined frequency and output to the induction line 11. In the initial state, since the load on the induction line 11 is the minimum load, as shown in FIG. 2C, the inverter energization rate of the switching element 61 of the inverter 36 is reduced from 70% according to the load {FIG. (C) is reduced to 40%}, and the step-down controller 58 lags behind and decreases the voltage rate in the step-down circuit 35 according to the inverter energization rate of the inverter 36 (reduced to 50% in FIG. 2 (c)). Then, the step-down control is executed by pulse-controlling the step-down switching element 52 with the energization rate (step-down circuit energization rate) corresponding to the decreased voltage rate. By this step-down control, the output DC voltage after step-down is controlled to the lowest DC voltage. Then, according to this, the inverter energization rate of the inverter 36 increases and returns to 70%. Due to the slower response of the step-down controller 58 than the inverter 36, the correction voltage rate output from the correction voltage forming unit 83 next becomes 0% due to the inverter energization rate of the inverter 36 and is output from the voltage rate calculation unit 85. The voltage rate is not changed, and the voltage rate in the step-down circuit 35 is maintained as it is (maintained at 50%).

  Thereafter, when the conveyance of the article by one or a plurality of conveyance carts 12 is started and the load on the induction line 11 is increased, the inverter energization rate of the switching element 61 in the inverter 36 is changed according to the current flowing through the induction line 11. The current flowing up through the induction line 11 is controlled to a constant alternating current. Thus, when the inverter energization rate of the switching element 61 increases and exceeds 75%, the step-down controller 58 delays and increases the voltage rate in the step-down circuit 35 according to the inverter energization rate of the inverter 36 {FIG. In c), the voltage is increased to 70%}, and the control for increasing the output voltage is executed by pulse-controlling the step-down switching element 52 at the current ratio (voltage step-down circuit current ratio) corresponding to the set voltage ratio. By this control, the DC voltage output from the step-down circuit 35 increases. Then, according to this, the inverter energization rate of the inverter 36 falls and returns to 70%. Due to the slower response of the step-down controller 58 than the inverter 36, the correction voltage rate output from the correction voltage forming unit 83 next becomes 0% due to the inverter energization rate of the inverter 36 and is output from the voltage rate calculation unit 85. The voltage rate is not changed, and the voltage rate in the step-down circuit 35 is maintained as it is (maintained at 70%).

  In this way, the voltage ratio is varied according to the inverter energization rate of the switching element 61 of the inverter 36 to perform step-down control, and the current and frequency flowing through the induction line 11 in the range of the inverter energization rate of 65% to 75% are as follows. The inverter 36 is controlled to be constant.

  Further, the current flowing through the induction line 11 is controlled by the inverter 36 to a constant alternating current, so that even if the alternating voltage of the alternating current power supply 32 fluctuates and the direct current voltage rectified by the rectifier 33 fluctuates, this fluctuation Absorbed.

  When the operation is stopped, the start conductor 43 is opened, the stop conductor 45 is closed, the direct current output to the step-down circuit 35 is interrupted, and then the connection of the alternating current power supply 32 is disconnected.

  As described above, according to the first embodiment, the current flowing through the induction line 11 is controlled to a constant current, and the input voltage of the inverter 36 depends on the load of the induction line 11, that is, the current flowing through the induction line 11. The power loss in the inverter 36, which is the value when the constant current is switched with respect to the input voltage, is reduced by stepping down in accordance with the energization rate (inverter energization rate) of the switching element 61 of the changing inverter 36. In addition, the level of switching noise of the inverter 36 can be lowered.

Further, when the energization rate (inverter energization rate) of the switching element 61 of the inverter 36 is out of the range of 65% to 75%, the voltage of the direct current output to the inverter 36 is controlled by the step-down circuit 35. The energization rate of the switching element 61 (inverter energization rate) can be maintained at 70%, so that it is possible to stably respond to fluctuations in the current of the induction line 11 quickly and to supply a constant current to the induction line 11.
[Embodiment 2]
FIG. 4 is a circuit configuration diagram of a contactless power supply facility including a power supply device for the contactless power supply facility according to Embodiment 2 of the present invention. Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 4, the circuit of the power receiving unit 22 of the transport carriage 12 connects the input end of a saturable reactor 27 having an intermediate tap in parallel with the resonance capacitor 26 of the resonance circuit, and the intermediate tap of the saturable reactor 27. A rectifier 28 is connected to the (output terminal), an output capacitor 29 is connected in parallel to the output side of the rectifier 28, and an inverter 23 is connected to the output capacitor 29 in parallel. The saturation voltage of the saturable reactor 27 is set according to the rated power required by the inverter 23 and the traveling motor 18, and the saturation voltage and the output rated voltage of the power receiving unit 22 {the intermediate tap of the saturable reactor 27 (output terminal ) Corresponding to the voltage}, the turn ratio of the coil windings of the input end and the output end of the saturable reactor 27 is set.

  Further, the current controller 62 is supplied with the DC voltage and DC current input to the inverter 36, and is input with the step-up ratio of the output voltage from the high-frequency transformer 30, and the current controller 62 receives the input voltage of the inverter 36. The current of the induction line 11 is calculated based on the current / boost ratio, and the pulse width (energization ratio) of the pulse signal for driving the switching element 61 to obtain a constant AC current set in advance is obtained. ing. In addition, the current controller 62 outputs the energization rate of the pulse signal of the driving switching element 61 to the step-down controller 58.

  The step-down controller 58 measures the DC voltage and DC current output from the rectifier 33, and as shown in FIG. 5, a load calculation unit 81, a target DC voltage calculation unit 82, and a correction voltage formation unit 83 ′. And an adder 84, a voltage rate calculation unit 85 ′, an energization rate calculation unit 86, and a pulse drive unit 87.

  The load calculation unit 81 calculates the power consumed by the induction line 11 based on the measured DC voltage and DC current, and monitors the load on the induction line 11. The electric power calculated by the direct current voltage and direct current input to the step-down circuit 35 has no means for storing a large amount of energy before reaching the induction line 11, so that the electric power (load) consumed by the induction line 11 is lost. Is considered.

  The target DC voltage calculation unit 82 compares the load of the induction line 11 obtained by the load calculation unit 81 with a preset rated load, and calculates how the preset rated voltage is changed. A calculation unit that divides the load on the induction line 11 by the rated load and multiplies the rated voltage to obtain a target DC voltage to be output to the inverter 36 and outputs the target DC voltage to the adder 84.

  Further, the correction voltage forming unit 83 ′ confirms the energization rate (inverter energization rate) of the switching element 61 of the inverter 36 that is being input, and when the inverter energization rate is lower than 65%, the inverter energization rate decreases. A correction voltage for correcting the target DC voltage to a low value is output to the adder 84, and when the inverter current ratio becomes higher than 75%, a correction voltage for correcting the target DC voltage to be high according to an increase in the inverter current ratio. Is output to the adder 84. The upper limit value α of the correction voltage of the correction voltage forming unit 83 ′ is set so as to pull back the inverter energization rate within 75% according to the load of the induction line 11, and the lower limit value β of the correction voltage is set to the induction line 11. In accordance with the load, the inverter energization rate is set to 65% or more.

  The adder 84 adds the target DC voltage obtained by the target DC voltage calculation unit 82 and the correction voltage output from the correction voltage forming unit 83 ′ to obtain a set DC voltage (setting value), It outputs to the voltage rate calculation part 85 '.

  The voltage rate calculation unit 85 ′ divides the set DC voltage by the DC voltage (measured value) output from the rectifier 33, and the ratio of the set DC voltage to the DC voltage (measured value) input to the step-down circuit 35. (Voltage rate) is obtained, and this voltage rate is output to the energization rate calculator 86.

  The energization rate calculation unit 86 obtains the energization rate (step-down circuit energization rate) of the step-down switching element 52 based on the voltage rate obtained by the voltage rate calculation unit 85 ′, and outputs it to the pulse drive unit 87. The pulse drive unit 87 The step-down switching element 52 is PWM-controlled by the step-down circuit energization rate obtained by the energization rate calculation unit 86 (step-down control is executed).

The operation of the above-described configuration of the step-down controller 58 will be described.
The load calculating unit 81 calculates the power consumed by the induction line 11 from the measured DC voltage and DC current to determine the load of the induction line 11, and the target DC voltage calculating unit 82 calculates the calculated power (load). Accordingly, a target DC voltage to be output to the inverter 36 is obtained.

  Next, the target DC voltage is corrected by the correction voltage forming unit 83 ′ and the adder 84. That is, when the input current ratio of the inverter 36 is less than 65%, the calculated target DC voltage is reset to a low value by a correction voltage formed according to the current ratio, and the current ratio is reduced to 75%. If it exceeds, the determined target DC voltage is reset to a higher value by the correction voltage formed in accordance with the energization rate.

Next, in the voltage rate calculation unit 85 ′, the reset set DC voltage is divided by the DC voltage (measured value) output from the rectifier 33 to obtain the ratio (voltage rate) of the set DC voltage.
Subsequently, in the energization rate calculation unit 86, the step-down circuit energization rate of the step-down switching element 52 is obtained from the obtained voltage rate, and in the pulse drive unit 87, the step-down switching element 52 is PWM-controlled by this energization rate (step-down control is performed). Run).

"Action"
The operation of the non-contact power supply facility will be described. When the power supply device 31 is turned on, the load on the induction line 11 is the minimum load. When the AC power supply 32 is connected to the power supply device 31, the start conductor 43 is opened and the stop conductor 45 is closed. In addition, the AC voltage of the AC power supply 32 connected to the power supply device 31 has a rating of AC200V and varies within a range of AC180V to 242V.

  When the AC power supply 32 is connected to the power supply device 31, the AC current is converted into a DC current by the rectifier 33 and output to the start / stop circuit 34. At this time, since the start conductor 43 is opened and the stop conductor 45 is closed, the inrush current at the time of activation is suppressed (limited) by the inrush resistor 41 and consumed by the discharge resistor 44. After a predetermined time, the starting conductor 43 is closed, the inrush resistor 41 is short-circuited, and then the stop conductor 45 is opened, and a stable DC current with the inrush current eliminated is output to the step-down circuit 35. At this time, the DC voltage after rectification by the rectifier 33 changes to DC240V when AC is 180V, DC270V when AC200V, and DC330V when AC242V.

  In the initial state, the load of the induction line 11 is the minimum load, and the step-down controller 58 sets a voltage rate corresponding to the minimum load of the induction line 11 being monitored, and steps down with the energization rate according to the set voltage rate. The step-down control is executed by controlling the switching element 52 for pulses. With this step-down control, the output DC voltage after step-down is controlled to the lowest DC voltage.

  The stepped down DC voltage of the step-down circuit 35 is output to the inverter 36. In the inverter 36, the current flowing through the induction line 11 is controlled to a constant alternating current by PWM control of the switching element 61 by the current controller 62, converted to a predetermined frequency, and output to the induction line 11. At this time, the inverter 36 can execute constant current control in a range of 65% to 75% of the energization rate because the input DC voltage is a low DC voltage corresponding to the minimum load.

  Next, the conveyance of the article by one or a plurality of conveyance carts 12 is started, and the load on the guide line 11 increases. When the load on the induction line 11 increases, the step-down controller 58 decreases the voltage rate according to the load (after stepping down) and increases the DC voltage. Thereby, the current flowing into the induction line 11 is controlled by the step-down circuit 35 to a substantially constant alternating current. At this time, even if the AC voltage of the AC power supply 32 fluctuates and the DC voltage after rectification by the rectifier 33 fluctuates, this fluctuation is absorbed by the step-down control of the step-down circuit 35.

  The raised DC voltage of the step-down circuit 35 is output to the inverter 36. In the inverter 36, the current flowing through the induction line 11 is controlled to a constant alternating current by PWM control of the switching element 61 by the current controller 62, converted to a predetermined frequency, and output to the induction line 11. At this time, the inverter 36 can execute constant current control in a range of 65% to 75% of the energization rate because the input DC voltage is a high DC voltage.

  In this way, the voltage ratio is varied depending on the load state of the induction line 11 to perform step-down control, and the current flowing through the induction line 11 is controlled to a constant alternating current by the step-down circuit 35 and the inverter 36, and the current Is controlled to a predetermined frequency by the inverter 36.

  When the operation is stopped, the start conductor 43 is opened, the stop conductor 45 is closed, the direct current output to the step-down circuit 35 is interrupted, and then the connection of the alternating current power supply 32 is disconnected.

  As described above, according to the second embodiment, the DC voltage output to the inverter 36 is stepped down by the step-down circuit 35 in accordance with the load state of the induction line 11, so that the current flowing through the induction line 11 is reduced. It can be controlled substantially constant. Further, the inverter 36 can control the current flowing through the induction line 11 quickly and constantly, and the frequency of the current can be controlled to a constant frequency. Further, a DC voltage to be output to the inverter 36 is set according to the obtained load of the induction line 11, and this setting is corrected by the energization rate of the switching element 61 of the inverter 36, so that the inverter is based on the load and the energization rate. The DC voltage output to 36 is controlled, and the energization rate of the pulse signal that drives the switching element 61 of the inverter 36 can be maintained at 65% to 75%. Therefore, there is a margin in the control of the energization rate, and the current of the induction line 11 is reduced. Respond quickly to fluctuations.

  In addition, the current flowing through the induction line 11 is controlled to a constant current, and the input voltage of the inverter 36 is stepped down according to the load of the induction line 11, so that the value when the constant current is switched with respect to the input voltage is The power loss in the inverter 36 can be reduced, and the level of switching noise of the inverter 36 can be further reduced.

Further, in the step-down circuit 35, the load on the induction line 11 can be obtained stably by the measured DC voltage and DC current. The load of the induction line 11 can be obtained by measuring the current flowing through the induction line 11 and the applied voltage, but the current flowing through the induction line 11 is high-frequency and is formed by switching of the switching element 61. Measurement is difficult due to the rectangular wave.
[Other embodiments]
Instead of the step-down circuit 35 of the first and second embodiments, a step-down circuit 70 shown in FIG. 6A may be provided. The step-down circuit 70 includes an input capacitor 71 connected in parallel to the output of the start / stop circuit 34, a switching element 72 and a diode 73 connected in series between the start / stop circuit 34 and the inverter 36, and switching. A coil 74 connected to a connection point between the element 72 and the diode 73, an output capacitor 75 having a reverse polarity connected to the anode of the diode 73, and a step-down controller 58 (not shown in FIG. 6) for controlling the switching element 72. ). The cathode of the diode 73 is connected to the switching element 72. With this circuit configuration, when the switching element 72 is closed, the current input from the rectifier 33 excites the coil 74 to store energy, as indicated by the dashed arrow, and the output current Io is an output capacitor having a reverse polarity. 75, the current I of the coil 74 increases as shown by the solid arrow, as shown in FIG. When the switching element 72 is open, the energy stored in the coil 74 is output to the output capacitor 75 as indicated by the one-dot chain arrow, and the output current Io is output from the output capacitor 75 having the opposite polarity by the solid arrow. As shown in FIG. 6B, the current I of the coil 74 decreases.

At this time,
Imin = {Io × (1 + Toff / Ton)} − (Vin × Ton / 2L) Ton ripple current = (Vin / L) × Ton (1)
Toff ripple current = (Vo / L) × Toff (2)
Since (1) = (2),
(Vin / L) × Ton = (Vo / L) × Toff
Vo = (Ton / Toff) × Vin
Is required. Therefore, the voltage is stepped down when the Ton time of the switching element 72 is shorter than the Toff time, and the voltage is boosted when the Ton time is longer than the Toff time.

By controlling the Ton time and Toff time of the switching element 72 by the step-down controller 58, step-down control can be executed.
In the first and second embodiments, the step-down circuit 58 is provided in the step-down circuit 35 and the current control controller 62 is provided in the inverter 36. However, the step-down circuit 35 and the inverter 36 are controlled by being integrated into one controller. You may do it.

DESCRIPTION OF SYMBOLS 11 Guide line 12 Carriage cart 14 Capacitor 15 Variable inductor 18 Traveling motor 21 Pickup coil 22 Power receiving unit 23 Inverter 24 Resonance capacitor 25 Rectifier 26A Inductor 26B Diode 27 Output voltage control switching element 28 Output capacitor 29 Output controller 30A High frequency transformer 30B Variable Current source 31 Power supply device 32 AC power source 33 Rectifier 34 Start / stop circuit 35 Step-down circuit 36 Inverter 51 Input capacitor 52 Step-down switching element 53 Coil 55 Diode 57 Output capacitor 58 Step-down controller 61 Switching element 62 Current control controller

Claims (2)

A load in which a power line fluctuates from an electromotive force induced in the power receiving coil by arranging a guide line along a moving path of the mobile object, and providing a power receiving coil on the mobile object facing the guide line. In the non-contact power feeding facility fed to the power line, a power supply device that supplies a constant alternating current of a predetermined frequency to the induction line,
A rectifier circuit that converts alternating current from an alternating current power source into direct current;
A step-down circuit for stepping down a DC voltage converted by the rectifier circuit;
An inverter that converts a DC voltage current stepped down by the step-down circuit into a constant AC current having a predetermined frequency by a plurality of switching elements respectively driven by a pulse signal and outputs the constant AC current to the induction line;
The step-down circuit corrects the DC voltage low according to a decrease in the inverter current ratio, and corrects the DC voltage high according to an increase in the inverter current ratio, so that the switching element of the inverter has the predetermined frequency. The DC voltage is controlled in accordance with the load of the induction line so that the average current ratio is 50% or more with respect to the half cycle of and the AC current output to the induction line can be controlled to the constant AC current. A power supply apparatus for a contactless power supply facility. The range of the energization rate is set to 65% to 75%,
The step-down circuit corrects the DC voltage corresponding to the load to be low when the pulse signal energization rate is less than 65%, and the pulse signal corresponds to the load when the pulse signal energization rate exceeds 75%. The power supply device for a non-contact power supply facility according to claim 1, wherein the voltage of the power supply is corrected to be high.

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