JP2005056277A - Electromagnetic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide electromagnetic equipment having a variable reactance function which can be controlled in high-speed. <P>SOLUTION: A first controllable valve device 15 and a first diode 17, a second controllable valve device 16 and a second diode 18 and a capacitor 14 are connected in parallel to each other between P and N terminals of a rectifier 11. The first controllable valve device 15 and a second controllable valve device 16 are connected so that forward current may flow from the rectifier 11. The first diode 17 is connected between the N terminal of the rectifier 11 and the first controllable valve device 15 so that an anode is at the rectifier 11 side. The second diode 18 is connected between the P terminal of the rectifier 11 and the second controllable valve device 16 so that a cathode is at the rectifier 11 side. A variable reactance 13 has a variable reactance function. One terminal of DC control winding 20 is connected between the first controllable valve device 15 and the first diode 17, and the other terminal is connected between the second controllable valve device 16 and the second diode 18. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electromagnetic device having a variable reactance function capable of high-speed control.

  As a control of the direct current of the control winding of the electromagnetic device having a variable reactance function, a control device using a chopper circuit as shown in FIG. 7 can be considered.

  The rectifier 31 is configured to convert the AC voltage of the AC control power supply 1 into a DC voltage and supply the input DC power supply voltage to the chopper circuit 32. The chopper circuit 32 includes an IGBT 34 and a diode 35. The chopper circuit 32 is formed by connecting the collector of the IGBT 34 to the P terminal of the rectifier 31, connecting the emitter of the IGBT 34 and the cathode of the diode 35, and connecting the anode of the diode 35 to the N terminal of the rectifier 31.

  The variable reactance device 33 has an AC winding 36 and a control winding 37 in the magnetic core. In the variable reactance device 33, one terminal of the control winding 37 is connected between the IGBT 34 and the diode 35, and the other terminal of the control winding 37 is connected to the N terminal of the rectifier 31. The variable reactance device 33 has a variable reactance function that changes the reactance of the AC winding 36 in accordance with the DC control current of the control winding 37 (see, for example, Patent Documents 1 and 2).

Below, the effect | action of the electromagnetic device 30 shown in FIG. 7 is demonstrated.
When the reactance of the AC winding 36 is decreased, the chopper circuit 32 including the IGBT 34 and the diode 35 increases the DC control current of the control winding 37 based on a signal from a control command circuit (not shown). As a result, the reactance of the AC winding 36 is reduced. Conversely, when the reactance of the AC winding 36 is increased, the chopper circuit 32 decreases the DC control current of the control winding 37. As a result, the reactance of the AC winding 36 increases.

  8 is a diagram showing (A) the gate signal waveform of the IGBT, (B) the collector-emitter voltage waveform of the IGBT, and (C) the output voltage waveform of the chopper circuit for the control apparatus for the electromagnetic device shown in FIG. is there. As shown in FIG. 8, the output voltage average value Eo of the chopper circuit 32 is represented by Eo = E × T1 / T, where T is the ON / OFF cycle, T1 is the ON width, and E is the input DC power supply voltage of the chopper circuit 32. It is almost represented by.

JP-A-9-330829 JP 2003-68539 A

However, the electromagnetic device 30 shown in FIG. 7 has the following problems.
For example, in order to obtain a device that adjusts reactance to a control command value in 0.1 seconds or less, it is necessary to increase or decrease the DC control current of the control winding 37 in 0.1 seconds or less. In general, when the time constant of the control winding 37 is τ, the resistance of the control winding 37 is R, the inductance is L, and the DC voltage is Eo, the current I is given by the following equation.
I = Eo / R × {1-exp (−t / τ)}
Here, τ = L / R.
From this equation, it is clear that even if the time constant τ is large, the current I increases in proportion to Eo, so that it is sufficient to increase Eo when it is desired to speed up the response.

  For example, when the resistance R of the control winding 37 is 0.1 ohm and the inductance L is 0.1H, the time constant τ is 1 second. When the rated current is 100 A, a voltage of 10 V (100 A × 0.1 ohm) is applied to the control winding 37 in a steady state. At this time, if a voltage of 105 V is applied to the control winding 37 by the chopper circuit 32, 100 A can be reached in 0.1 seconds.

  Next, consider when the current is decreased. The operation of the electromagnetic device 30 shown in FIG. 7 will be described in more detail. When the IGBT 34 of the chopper circuit 32 is on, a current I flows through the rectifier 31, the IGBT 34, and the control winding 37. Next, when the IGBT 34 is turned off, the current I of the control winding 37 circulates through the diode 35. In the steady state, a current that increases during the ON period T1 of the IGBT 34 and a current that decreases during the OFF period (T-T1) of the IGBT 34 are balanced. The factor that reduces the current during the off period of the IGBT 34 is mainly the resistance of the control winding 37. For this reason, even if the ON period T1 of the IGBT 34 is set to 0, the current decay is small, and it takes about four times the time constant τ of the control winding 37 to reach 0. In the example of τ = 1 second described above, it takes about 4 seconds.

  As described above, the electromagnetic device 30 shown in FIG. 7 has a problem that high-speed control cannot be performed because the DC control current of the variable reactance device 33 having the variable reactance function cannot be reduced at high speed.

  The present invention has been made paying attention to such a problem, and an object thereof is to provide an electromagnetic device capable of high-speed control.

  In order to achieve the above object, an electromagnetic device according to the present invention has an AC winding and a DC control winding in a magnetic core, and the AC winding has an AC winding according to the magnitude of a DC current passing through the DC control winding. In an electromagnetic apparatus having a variable reactance function having a characteristic of reactance change, a capacitor is connected between the positive and negative terminals PN of a DC power supply that passes a DC current to the DC control winding, and the positive terminal P of the DC control power supply and the DC control A first controllable valve device is inserted in series between the first terminal of the winding and a second controllable device is connected between the second terminal of the DC control winding and the negative terminal N of the DC control power supply. A control valve device is inserted in series, and the first and second controllable valve devices are connected in a forward direction in a closed circuit from the positive terminal P to the negative terminal N via the DC control winding; In addition, the negative terminal N of the DC control power supply A first diode is inserted in series between the first terminal of the DC control winding and a second diode is connected between the second terminal of the DC control winding and the positive terminal P of the DC control power supply. Are connected in series, and the first and second diodes are connected in opposite directions in a closed circuit from the positive terminal P to the negative terminal N via the DC control winding.

  The electromagnetic device according to the present invention is not limited to a single phase, and may be configured by a multiphase circuit such as a three-phase circuit. For each phase DC control winding of a multi-phase variable reactance device, a DC control circuit is provided for each phase individually, or each phase DC control winding is connected in series or in parallel to provide a DC control circuit collectively. May be. In the control apparatus for an electromagnetic device according to the present invention, the first controllable valve device and the second controllable valve device are preferably composed of controllable valve devices using semiconductors such as IGBT, power MOSFET, and GTO.

  In the control apparatus for an electromagnetic device according to the present invention, the first controllable valve device, the second controllable valve device, the first diode, and the second diode are combined in consideration of their respective electrical characteristics. It is preferable to select a product that matches the above characteristics. Since an element such as a diode-embedded controllable valve device in which a controllable valve device and a diode are integrated in parallel is generally available, such an element may be used. In this case, the combination characteristics of the controllable valve device and the diode are satisfied in advance, and the design and manufacture becomes easy.

  In the electromagnetic device according to the present invention, when the first controllable valve device and the second controllable valve device are on, the DC voltage E is applied to the DC control winding. When the first controllable valve device and the second controllable valve device are off, a current directed to charge the capacitor flows through the DC control winding via the first diode and the second diode. For this reason, in the electromagnetic device according to the present invention, a voltage of E is applied to the control winding during the on period of the first controllable valve device and the second controllable valve device, and −E is applied during the off period. As a result, the electromagnetic device according to the present invention can change the DC control current at a high speed in both cases of startup and shutdown, and high-speed control is possible.

  The electromagnetic device according to the present invention may be used as a voltage stabilization device by connecting terminals of an AC winding in parallel to a distribution line. In this case, by adjusting the reactive power, the voltage of the distribution line can be adjusted, or the voltage of the power source or the load or the power factor can be adjusted for a general load.

  The electromagnetic device according to the present invention may be used as a voltage stabilizing device by connecting a terminal of an AC winding in series with a distribution line. In this case, the voltage of the distribution line can be adjusted by changing the series impedance. Moreover, it is connected to the line which comprises a loop system | strain, and can control an electric power flow as a phase adjuster.

  The electromagnetic device according to the present invention may be used as a transformer in which the electromagnetic device has a plurality of AC windings for one phase. In this case, the reactive power adjustment and the transformation action can be performed together.

  According to the present invention, an electromagnetic device capable of high-speed control can be provided.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 6 show an electromagnetic device according to an embodiment of the present invention.
As shown in FIG. 1, the electromagnetic device 10 of the present invention includes a rectifier 11, an H-type chopper circuit 12, and a variable reactance device 13.

  The rectifier 11 is configured to convert an AC voltage of the AC control power supply 1 into a DC voltage and supply an input DC power supply voltage to the H-type chopper circuit 12.

  The H-type chopper circuit 12 includes a capacitor 14, a first controllable valve device 15, a second controllable valve device 16, a first diode 17, and a second diode 18. The capacitor 14 is connected between the PN terminals of the rectifier 11. The first controllable valve device 15 and the second controllable valve device 16 are made of IGBT, and the collector of the IGBT is on the P terminal side of the rectifier 11 and the emitter is on the N terminal side of the rectifier 11 so that forward current flows from the rectifier 11. Each is connected.

  The first diode 17 is connected between the N terminal of the rectifier 11 and the first controllable valve device 15. The first diode 17 has an anode connected to the N terminal of the rectifier 11 and a cathode connected to the emitter of the first controllable valve device 15. The second diode 18 is connected between the P terminal of the rectifier 11 and the second controllable valve device 16. The second diode 18 has an anode connected to the collector of the second controllable valve device 16 and a cathode connected to the P terminal of the rectifier 11.

  The first controllable valve device 15 and the first diode 17, the second controllable valve device 16 and the second diode 18, and the capacitor 14 are connected in parallel with each other between the PN terminals of the rectifier 11. The circuit configuration of the H-type chopper circuit 12 is generally H-shaped.

  The variable reactance device 13 has an AC winding 19 and a DC control winding 20 in the magnetic core. In the variable reactance device 13, one terminal of the DC control winding 20 is connected between the first controllable valve device 15 and the first diode 17, and the other terminal of the DC control winding 20 is the second controllable valve. Connected between the device 16 and the second diode 18. The variable reactance device 13 has a variable reactance function that changes the reactance of the AC winding 19 in accordance with the magnitude of the DC control current that communicates with the DC control winding 20.

  As shown in FIG. 1, the variable reactance device 13 is composed of a variable reactor using an orthogonal magnetic core, but is not limited thereto, and has an AC winding 19 and a DC control winding 20 in the magnetic core. It is only necessary to have a variable reactance function in which the reactance of the AC winding 19 changes in accordance with the magnitude of the DC control current communicating with the winding 20.

Next, the operation will be described.
In the electromagnetic device 10 according to the present invention, when reducing the reactance of the AC winding 19, the chopper circuit 12 increases the DC control current of the DC control winding 20 based on a signal from a control command circuit (not shown). As a result, the reactance of the AC winding 19 is reduced. Conversely, when the reactance of the AC winding 19 is increased, the chopper circuit 12 decreases the DC control current of the DC control winding 20. As a result, the reactance of the AC winding 19 increases.

  FIG. 2 shows (A) the gate signal waveforms of the first controllable valve device and the second controllable valve device, and (B) the first controllable valve device and the second controllable device for the control apparatus for the electromagnetic device shown in FIG. It is a figure which respectively shows the voltage waveform between collector-emitters of a valve device, and the output voltage waveform of (C) chopper circuit. As shown in FIG. 2, in the electromagnetic device 10 according to the present invention, a DC voltage E is applied to the DC control winding 20 when the first controllable valve device 15 and the second controllable valve device 16 are on. When the first controllable valve device 15 and the second controllable valve device 16 are off, a current flowing in the direction of charging the capacitor 14 flows through the DC control winding 20 via the first diode 17 and the second diode 18. As a result, as shown in FIG. 2C, the voltage waveform applied to the DC control winding 20 is a square wave with an output voltage of ± E and a period of T. Therefore, by changing the ON period T1 of the first controllable valve device 15 and the second controllable valve device 16, the average voltage Eo can be changed from -E to + E.

  As shown in FIG. 2C, in the electromagnetic device 10 according to the present invention, the ON period T1 of the first controllable valve device 15 and the second controllable valve device 16 is E, and the OFF period (T-T1) is -E. Is applied to the DC control winding 20. As a result, the electromagnetic device 10 according to the present invention can change the DC control current at high speed in both cases of startup and shutdown, and high-speed control is possible.

  In other words, the current of the DC control winding 20 is attenuated, in other words, the stored energy of the DC control winding 20 returns to the chopper circuit 12. However, the rectifier 11 cannot return energy to the AC control power supply 1. For this reason, the electromagnetic device 10 according to the present invention is provided with a capacitor 14 for temporarily storing the returned energy. Even in the electromagnetic device 30 shown in FIG. 7, a capacitor may be inserted after the rectifier 31, but it is for suppressing a surge voltage applied to the IGBT 34 and is not indispensable for operation. However, in the electromagnetic device 10 according to the present invention shown in FIG. 1, the capacitor 14 is indispensable.

  Note that when the current of the DC control winding 20 becomes zero, the current flowing through the first diode 17 and the second diode 18 also becomes zero. Therefore, no reverse current flows through the DC control winding 20.

  As shown in FIG. 3, the electromagnetic device 10 according to the present invention is used as a voltage stabilizer by connecting terminals of an AC winding 19 in parallel to a distribution line having an AC power source 2, a series reactor 3 and a load 4. I can do it. In this case, by adjusting the reactive power, the voltage of the distribution line can be adjusted, or the voltage or power factor of the power source or load can be adjusted for the general load 4.

  Moreover, as shown in FIG. 4, the electromagnetic device 10 according to the present invention can be used as a voltage stabilizing device by connecting the terminals of the AC winding 19 in series to the distribution line having the AC power source 2 and the load 4. I can do it. In this case, the voltage of the distribution line can be adjusted by changing the series impedance. Moreover, it is connected to the line which comprises a loop system | strain, and can control an electric power flow as a phase adjuster.

  Furthermore, as shown in FIG. 5, the electromagnetic device 10 according to the present invention is used as a transformer if the variable reactance device 13 has two AC windings 19 for one phase. In this case, the terminal of one AC winding 19 is connected to the circuit having the AC power supply 2 and the series reactor 3, and the terminal of the other AC winding 19 is connected to the circuit having the load 4. Thereby, the electromagnetic device 10 by this invention can perform reactive power adjustment and a transformation effect | action together. Even if the number of AC windings 19 for one phase of the variable reactance device 13 is three or more, it functions as a control device having both reactive power adjustment and a transforming action.

  As shown in FIGS. 3 to 5, the electromagnetic device 10 according to the present invention includes a DC control current circuit including an H-type chopper circuit 12 and a variable reactance device in which the reactance of the AC winding 19 changes according to the DC control current. 13 is realized in combination with 13. For this reason, it is clear that the AC winding 19 of the variable reactance device 13 to be applied changes variously according to the target control function.

  The first controllable valve device 15, the second controllable valve device 16, the first diode 17 and the second diode 18 of the control apparatus for the electromagnetic device shown in FIG. And a diode built-in controllable valve device 21 in which a diode and a diode are integrated in parallel. In this case, the electromagnetic device 10 according to the present invention can be configured by properly using the controllable valve device and the diode depending on whether the gate signal is input to the controllable valve device. In addition, the combination characteristics of the controllable valve device and the diode are satisfied in advance, which facilitates design and manufacture.

It is a circuit diagram which shows the electromagnetic device of embodiment of this invention. (A) Waveform diagram showing gate signals of the first controllable valve device and the second controllable valve device of the control apparatus of the electromagnetic device shown in FIG. 1, (B) the first controllable valve device and the second controllable valve device. FIG. 6 is a waveform diagram showing the collector-emitter voltage of FIG. 2, and (C) is a waveform diagram showing the output voltage of the chopper circuit. It is a circuit diagram which shows the voltage stabilization apparatus which connected the electromagnetic device shown in FIG. 1 in parallel. It is a circuit diagram which shows the voltage stabilization apparatus which connected the electromagnetic device shown in FIG. 1 in series. It is a circuit diagram which shows the transformer which uses the electromagnetic device shown in FIG. It is a circuit diagram which shows the modification of the 1st controllable valve device of the electromagnetic device shown in FIG. 1, a 2nd controllable valve device, a 1st diode, and a 2nd diode. It is a circuit diagram which shows the structural example of an electromagnetic device. (A) Waveform diagram showing IGBT gate signal in configuration example of electromagnetic device, (B) Waveform diagram showing IGBT collector-emitter voltage, (C) Waveform diagram showing output voltage of chopper circuit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 AC control power supply 2 AC power supply 3 Series reactor 4 Load 10 Electromagnetic apparatus of this invention 11 Rectifier 12 H-type chopper circuit 13 Variable reactance apparatus 14 Capacitor 15 1st controllable valve device 16 2nd controllable valve device 17 1st diode 18 Second diode 19 AC winding 20 DC control winding 21 Controllable valve device with built-in diode 30 Example of electromagnetic device 31 Rectifier 32 Chopper circuit 33 Variable reactance device 34 Controllable valve device 35 Diode 36 AC winding 37 DC control winding

Claims (1)

In an electromagnetic device having a variable reactance function having an AC winding and a DC control winding in a magnetic core, and having a characteristic that reactance of the AC winding changes according to the magnitude of a DC current passing through the DC control winding.
A capacitor is connected between the positive and negative terminals PN of a DC power source that passes a DC current through the DC control winding;
A first controllable valve device is inserted in series between the positive terminal P of the DC control power source and the first terminal of the DC control winding, and the second terminal of the DC control winding and the DC control power source A second controllable valve device is inserted in series with the negative terminal N, and the first and second controllable valve devices reach from the positive terminal P to the negative terminal N via the DC control winding. Connect in the forward direction in the closed circuit,
Further, a first diode is inserted in series between the negative terminal N of the DC control power supply and the first terminal of the DC control winding, and the second terminal of the DC control winding and the positive terminal of the DC control power supply are connected. A second diode is inserted in series with the terminal P, and the first and second diodes are reversed in a closed circuit from the positive terminal P to the negative terminal N through the DC control winding. Electromagnetic equipment characterized by such connection.

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