JP2010280235A - Noncontact current collector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such a problem that a device which connects a serial capacitor with second coil output, and controls a PWM converter in noncontact current collection for taking out electric power from alternating current power with large internal inductance with a power factor of 1, needs to install the serial capacitor at a traveling vehicle side, and thus traveling vehicle becomes heavy. <P>SOLUTION: In the noncontact current collector, the PWM converter changes alternating current output inducted by a second coil to direct current output. In the noncontact current collector, a first side capacitor is serially connected to an input side of a first coil, the PWM converter is controlled to become an equivalent series circuit of a resistor and the capacitor by PWM modulation, and a total serial reactance in which the first side capacitor, leakage inductance of the first coil, leakage inductance of a second coil, and an equivalent capacitor of the PWM converter are expressed at the second coil side is made zero. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an apparatus for collecting electricity in a non-contact manner on an electric vehicle.

  The present applicant has previously proposed a PWM converter in which capacitive impedances are connected in series in order to increase the efficiency of a PWM converter connected to an AC power supply having a large internal impedance and to reduce the capacity of a switching element. (See Patent Document 1).

FIG. 5 shows the main circuit and power supply system of the non-contact current collector of the prior application shown in FIG. 5, and the single-phase equivalent circuit of the main circuit and power system of the non-contact current collector of FIG. This will be described in detail with reference to the drawings and the control circuit diagram of the PWM converter used in the non-contact current collector of the prior application of FIG.
In FIG. 5, 4 is a PWM converter, 5 is a DC power supply as a load, 7 is an AC power supply, 8 is an internal resistance, 9 is an internal inductance, 10 is a PWM converter unit, and 33 is a series capacitor.
In FIG. 4, 1 represents a primary coil and 2 represents a secondary coil.
In FIG. 3, 21 is an arithmetic circuit, 22 is an F / V conversion circuit, 23 is a capacity command generator, 24 is a divider, 25 is a comparator, 26 is a triangular wave generator, and 27 is a gate generation circuit.

In FIG. 5, an internal resistance 8, an internal inductance 9, and a series capacitor 33 are connected in series to a three-phase AC power supply 7, and further in a PWM converter 4 connected in series and a DC power supply 5 as a load. AC output is converted to DC output.
The prior application technology is a non-contact current collector for an auxiliary power source of a linear bullet train, and an AC power source 7 having a frequency that is about several times the commercial frequency depending on the vehicle traveling speed is connected to the primary coil 1 of FIG. Indicates the power to be supplied. 4 and 5 represent the same product. Secondary coil 2, series capacitor 33 and PWM converter unit 10 are mounted on a traveling vehicle (not shown).

In FIG. 4, the primary coil 1 is represented by a primary resistance R ₁ , a primary leakage inductance L ₁ , and an inductance L ₀₁ due to the main magnetic flux. The secondary coil 2 is represented by a secondary resistance R ₂ , a secondary leakage inductance L ₂ , and an inductance L ₀₂ due to the main magnetic flux. A mutual inductance M due to magnetic coupling exists between the primary coil 1 and the secondary coil 2, and there is a relationship of M ² = L ₀₁ × L ₀₂ . Since the primary coil 1 and the secondary coil 2 collect current in a non-contact manner, the magnetic gap is increased, the mutual inductance M is smaller than that of a normal transformer, and the leakage inductance of both coils is increased.

If the number of turns of the primary coil 1 and the secondary coil 2 is N ₁ and N ₂ , the turn ratio a is expressed as a = N ₁ / N ₂ . Therefore, when the mutual inductance M in FIG. 4 is ignored, the relationship between the resistance and the inductance in FIGS. 4 and 5 is as follows.
The value R _S of the internal resistance 8 in FIG. 5 is expressed as R _S = R ₁ / a ² + R ₂ by converting the primary resistance R ₁ to the secondary coil 2 side and using the secondary resistance R ₂ and the turn ratio a. Is done. Similarly, the value L _S of the internal inductance 9 is obtained by converting the primary leakage inductance L ₁ to the secondary coil 2 side, and using the secondary leakage inductance L ₂ and the turn ratio a, L _S = L ₁ / a ² + L ₂ It is represented by

  As shown in FIG. 4, when the PWM converter 4 is controlled so that the power factor = 1 in the prior art, the PWM converter unit 10 is represented by a series circuit of an equivalent capacitor Cb and a load resistor Rb.

A method of controlling the PWM converter 4 with a power factor = 1 in the non-contact current collecting main circuit of the prior application configured as above will be described.
In order to extract electric power from the AC power source 7 with a power factor = 1, it is necessary that reactances of the primary coil 1, the secondary coil 2, and the load system as a whole are zero. That is, in FIG. 6, the reactance of the series circuit of the internal inductance 9, the series capacitor 33, and the PWM converter unit 10 needs to be zero.
That is, if the total capacity of the series circuit of the series capacitor 33 and the PWM converter unit 10 is C, the reactance becomes zero if the condition of the expression (1) is established between the value L _S of the internal inductance 9.
However, since the series capacitor 33 having a capacitance C _C is previously connected, the equivalent capacitance Cb of the PWM converter section 10 satisfies the equation (2) will satisfy the equation (1).
Therefore, if the three-phase input terminal voltages Eu, Ev, and Ew of the PWM converter 4 shown in FIG. 5 are expressed by the following equations (3) to (5), the PWM converter unit 10 is equivalently equivalent to FIG. . Here, (1 / j) is an operator that delays the phase by 90 °.

FIG. 3 shows an example of a control circuit of a conventional PWM converter for this purpose. Reference numeral 21 denotes an input terminal voltage command value Eu from detected currents Iu and Iv.
^* , Ev ^* , Ew ^* calculation circuit, 24 is a divider, 25 is a comparator, 27 is a gate generation circuit, 26 is a triangular wave generator, 22 is an F / V converter, and 23 is a capacity command generator It is. The arithmetic circuit 21 performs the calculations of the above formulas (3) to (5). Where Iw
Is equal to (−Iu−Iv), and Iu and Iv have a 120 ° phase difference, and input terminal voltage command values Eu ^* and Ev.
^{* And} Ew ^* are calculated as in the following equations (6) to (8).

Ｆ/Ｖ変換器２２は電流検出値Ｉｕから２次コイルの電源角周波数ωを算出する。容量指令発生器２３は、電源内部インダクタンスＬｓとＦ/Ｖ変換器２２により算出されたωと外部容量Ｃｃの値より前記式（２）により等価容量Ｃｂの値を算出し、上記演算回路２１に出力する。
この外部容量Ｃｃの値は、例えば定格電源角周波数ωの時に式（１）で求められる値Ｃに近い値のコンデンサが接続される。

The F / V converter 22 calculates the power supply angular frequency ω of the secondary coil from the current detection value Iu. The capacity command generator 23 calculates the value of the equivalent capacity Cb from the power supply internal inductance Ls, the value of ω calculated by the F / V converter 22 and the value of the external capacity Cc by the above equation (2), and Output.
As the value of the external capacitance Cc, for example, a capacitor having a value close to the value C obtained by Expression (1) at the rated power supply angular frequency ω is connected.

For example, when the PWM converter unit 10 configured as described above has ω = 2π × 250 Hz, C = Cc = 1000 μF, and R = 0.1Ω, the absolute value | Zb | of the phase impedance of the PWM converter unit 10 in FIG. The total phase impedance | Za | of the series capacitor 33 and the PWM converter unit 10 is | Zb | = 0.1Ω,
| Za | = 0.64Ω, and | Za | / | Zb | = 6.4.
That is, when Cc = C, the voltage Vd applied to the series capacitor 33 and the PWM converter unit 10 in FIG. 4 is about 6 of the voltage applied to the series circuit of the load resistor Rb and the equivalent capacitance Cb of the PWM converter unit 10. .4 times. In other words, the voltage applied to the series circuit of the load resistor Rb and the equivalent capacitor Cb of the PWM converter unit 10 can be reduced.

JP 2000-83379 A

In the method in which the AC power source 7 described above is constituted by a three-phase AC power source 7 having a frequency of about several times the commercial frequency, and a series capacitor 33 is connected in series to the PWM converter 4, an AC having a large internal inductance L _S is obtained. Electric power can be extracted from the power source at a power factor = 1. However, there is a problem that the series capacitor 33 must be installed on the traveling vehicle side and the traveling vehicle becomes heavy.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a non-contact current collector capable of constituting a light traveling vehicle.

  According to the first aspect of the present invention, in the non-contact current collector that converts the AC output induced from the primary coil on the ground to the secondary coil of the traveling vehicle to the DC output by the PWM converter, on the input side of the primary coil A primary side capacitor is connected in series, and the PWM converter is controlled to be equivalently a series circuit of a resistor and a capacitor by PWM modulation, and the leakage inductance of the primary side capacitor and the primary coil and the secondary side are controlled. The non-contact current collector is characterized in that the total series reactance in which the leakage inductance of the coil and the equivalent capacity of the PWM converter are all expressed on the secondary coil side is zero.

  In the non-contact current collector, the power factor = 1 can be achieved by connecting a series capacitor to the primary coil on the power system side and the PWM converter connected to the secondary coil on the traveling vehicle side. Since the vehicle can be made small, the traveling vehicle can be lightened.

It is a figure for demonstrating the main circuit structure of the non-contact collector which concerns on the Example of this invention. It is the figure represented with the single phase equivalent circuit of the non-contact collector which concerns on the Example of this invention. It is the figure explaining the control circuit of the PWM converter used for the non-contact current collecting apparatus which concerns on the Example of this invention, and a prior application. It is the figure showing the non-contact current collecting device which connected the series capacitor to the secondary coil concerning the conventional example with the single phase equivalent circuit. It is a figure for demonstrating the main circuit structure of the non-contact collector which connected the series capacitor to the secondary coil which concerns on the conventional Example.

  A capacitor is connected in series to the ground side primary coil, and a power factor = 1 is achieved by the PMW converter on the secondary coil side.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a main circuit connection diagram of a non-contact current collector in which a capacitor is connected in series to a power supply system to which the present invention is applied.
FIG. 2 is a single-phase equivalent circuit of a non-contact current collector in which a capacitor is connected in series with the power supply system.
Reference numeral 34 denotes a primary side capacitor connected to the power supply system.
In the figure, the same reference numerals as those in FIGS. 5 and 4 denote similar components.
Hereinafter, FIG. 1 and FIG. 2 will be described with reference to FIG.

In FIG. 2, the relationship between the resistance and inductance of the primary coil 1 and the secondary coil 2 is expressed in the same manner as in FIG. Here, if the number of turns of the primary coil 1 and the secondary coil 2 is N ₁ and N ₂ , the turn ratio a is expressed as a = N ₁ / N ₂ . Therefore, if the mutual inductance M in FIG. 2 is ignored, the relationship between the resistance and the inductance in FIGS. 1 and 2 is expressed as R _S = R ₁ / a ² + R ₂ and L _S = L ₁ / a ² + L _2. .
Further, the capacitance C _C1 of the primary side capacitor 34 connected to the AC power source 7 in FIG. 2 is C _C = a ² × C _C1 when converted to the secondary coil 2 side. Therefore, the capacitance C _C1 of the primary capacitor 34 that is actually connected is obtained from C _C1 = C _C / a ² using the turns ratio a.

Therefore, the capacity command generator 23 of the PWM converter 4 used in the non-contact current collector obtains C _C = a ² × C _C1 using the capacity C _C1 of the primary capacitor 34 and the turn ratio a, and the formula ( Cb is calculated based on 2). Using this Cb, the PWM converter 4 is controlled in the same manner as in FIG. 5 by the control circuit in FIG. As a result, the total series reactance becomes zero representing the leakage inductance L ₂ and the equivalent capacitance Cb of the PWM converter of the primary side capacitor 34 and the leakage inductance L ₁ of the primary coil and the secondary coil at all secondary coil , Operated with power factor = 1.

  Here, it is necessary to provide hysteresis in the calculation result of the denominator so that the denominator of Expression (2) does not become zero depending on the value of the power supply angular frequency ω. In addition, the calculation result of Expression (2) may be negative. In such a case, the equivalent capacitance Cb operates as an inductance, and as a result, power factor = 1 is maintained.

The non-contact current collector has a problem that since the gap between the supply-side coil and the current-collection coil is large, the leakage inductance of the coil is large, and the power factor is low, so that a large output cannot be obtained. In the present invention, a primary capacitor is connected to the primary coil side of the non-contact current collector, and a PWM converter is connected to the secondary coil side.
The primary capacitor and the PWM converter operate as capacitive reactance so as to cancel out inductive reactance due to leakage inductance of the primary coil and the secondary coil.
Because of the primary capacitor connected in advance, the voltage drop corresponding to the reactance generated by the PWM converter is reduced, and the capacitance of the PWM converter can be reduced. Therefore, since the current collector of the traveling vehicle can be reduced, the traveling vehicle can be lightened, which is very useful for industrial use.

DESCRIPTION OF SYMBOLS 1 Primary coil 2 Secondary coil 4 PWM converter 5 DC power supply 7 AC power supply 8 Internal resistance 9 Internal inductance 10 PWM converter part 21 Calculation circuit 22 F / V converter 23 Capacity command generator 24 Divider 25 Comparator 26 Triangular wave generator 27 Gate generation circuit 33 Series capacitor 34 Primary side capacitor

Claims (1)

In a non-contact current collector that converts an AC output induced from a primary coil on the ground to a secondary coil of a traveling vehicle into a DC output by a PWM converter, a primary side capacitor is connected in series to the input side of the primary coil. The PWM converter is controlled by PWM modulation to be equivalently a series circuit of a resistor and a capacitor, and the primary capacitor, the leakage inductance of the primary coil, the leakage inductance of the secondary coil, and the PWM converter A non-contact current collector characterized in that the total series reactance in which all equivalent capacitances are expressed on the secondary coil side is zero.

Images