JP3379653B2 - Pulse generator and dust collector using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse generator and a pulse charging type dust collector using the same.

[0002]

2. Description of the Related Art In the case of a reactive load such as a pulse-charge type dust collector for efficiently collecting high-resistance dust, the surplus energy supplied from the pulse generator to the load is regenerated. It is desirable to regenerate on the input side to improve the efficiency of the system.

Such a pulse generator having a function of regenerating the surplus energy supplied to the load is used, for example, in a pulse charge type dust collector described in Japanese Patent Publication No. 57-43062. There are known methods.

FIG. 7 shows an example of a pulse charging type dust collector described in Japanese Patent Publication No. 57-43062, in which 24 is an input DC power source, 2 is a charging resistor for the main capacitor 3, and 3 is an input energy storage device. Main capacitor, 4 is a thyristor which is a main switch for discharging the electric charge accumulated in the main capacitor 3, 25 is a diode, and 8 is a thyristor 4.
And a reactor for limiting the current rising rate di / dt of the pulse current flowing through the diode 25, 15 is a step-up transformer, 16 is a primary winding of the step-up transformer 15, 17 is a secondary winding of the step-up transformer 15, 13 and 14 are output terminals of the pulse generator, 10 is a reactor for suppressing surge current, 11 is a capacitor for blocking direct current, and 12 is a dust collecting electrode.

In FIG. 7, the positive electrode of the input DC power supply 24,
A DC voltage E21 is constantly applied to the dust collecting electrode 12 in the polarity shown in the drawing through the dust collecting electrode 12, the surge current suppressing reactor 10, and the negative electrode path of the input DC power supply 24. That is,
A DC voltage -E24 is applied to the dust collecting electrode 12 with respect to GND.

The part within the broken line in FIG. 7 is the pulse generator, and the direct current voltage -E24 applied to the dust collecting electrode 12 is
Further, it has a function of superimposing a negative high voltage pulse.
The operation will be described with reference to FIG. 7 showing a circuit configuration and FIGS. 8 and 9 showing voltage and current waveforms of main parts in FIG.

In this circuit, in order to improve the energy transfer efficiency from the main capacitor 3 to the dust collecting electrode 12, when the turn ratio of the primary winding 16 and the secondary winding 17 of the step-up transformer 15 is set to 1: N. In addition, it is desirable that the ratio of the capacity of the main capacitor 3, the capacity of the DC current blocking capacitor 11 and the capacity of the dust collecting electrode 12 is about 0.9 · N ² : 10: 1.

When the turn-on signal is input to the gate of the thyristor 4 and the thyristor 4 turns on, the main capacitor 3
The electric charge stored in the main capacitor 3 from the illustrated positive electrode to the primary winding 16 of the step-up transformer 15, the reactor 8, the thyristor 4, and the negative electrode illustrated in FIG. It flows. Therefore, the secondary winding 17 of the step-up transformer 15 receives a pulse current i17 'corresponding to the turn ratio of the step-up transformer 15 from the opposite polarity side of the black circle in the secondary winding 17 of FIG. 12, the DC current blocking capacitor 11 and the secondary winding 17 flow through the path on the polarity side of the black circle in the figure. By this pulse current i17 ', the dust collecting electrode 1
A pulse voltage having a crest value V12 'with the polarity shown is applied to 2. That is, if the voltage of the dust collecting electrode 12 is v12 ', then v1
2'is the peak value for GND as shown in FIGS. 8 and 9.
A pulse voltage of V12 'is applied.

During the period τ1 'from when the current i4' starts to flow to zero again, the combined inductance Lt of the leakage inductance seen from the primary winding 16 of the step-up transformer 15, the inductor 8 and the inductance generated by the wiring. , Main capacitor 3, DC current blocking capacitor 11
Further, when the combined capacitance of the dust collecting electrode 12 seen from the step-up transformer 15 primary winding 16 is Ct, it is given by the following equation.

[Equation 1] After τ1 ′ after the thyristor 4 is turned on, the charge transferred to the dust collecting electrode 12 is in the opposite direction to the current i17 ′ in FIG. 7, from the positive electrode of the dust collecting electrode 12 to the secondary winding 16 of the step-up transformer 15, A pulse current flows through the negative electrode path of the DC current blocking capacitor 11 and the dust collecting electrode 12. For this reason, in FIG. 7, the primary winding 16 of the step-up transformer 15 is shown in the polarity side of the black circle in the figure, and the main capacitor 3, the diode 25, the reactor 8 and the path of the primary winding 16 in the opposite polarity side of the black circle in the figure are shown. The pulse current i25 shown in FIG.
The charges transferred to 2 are returned to the main capacitor 3 for input energy storage. The period τ3 ′ from when the pulse current i25 starts to flow to when the pulse current i25 becomes zero again is generally selected to be a value approximately equal to τ1 ′ determined by the above-mentioned formula 1.

In this circuit, from time t = τ1 to t = τ1 '+
Up to τ3 ′, the main electrodes of the thyristor 4 are reverse-biased, and after the recovery current flows, the thyristor 4 is cut off. Therefore, the charges transferred from the dust collecting electrode 12 to the main capacitor 3 for storing input energy again are input with a turn-on signal to the gate of the thyristor 4 after τp shown in FIG. 9, and the thyristor 4 is turned on. Is stored in the main capacitor 3 and energy is regenerated. At this time, the width of the pulse voltage output from the output terminals 13 and 14 of the pulse generating circuit to the dust collecting electrode 12 as the load is τ1 ′ + τ3 ′.

Therefore, the energy input from the input DC power supply 24 to the main capacitor 3 is, as shown in FIG. 9, the power supply voltage -E24 of the input DC power supply 1 and the regenerated voltage -E24 '.
Therefore, it is possible to realize a highly efficient pulse charging type dust collector.

By the way, in this pulse generator, since it is necessary to generate a pulse having a high voltage and a large current rising rate di / dt, the main switch generally has a high withstand voltage, a large current and a di / dt withstand capability. A semiconductor switching element such as a large thyristor is connected in series and parallel in the number corresponding to the withstand voltage, peak current, and di / dt withstand capability of the element.

[0013]

When semiconductor switching elements are connected in series and parallel, semiconductor switching elements having relatively uniform characteristics are selected and used, and between the elements when operated in serial and parallel connection. In order to evenly share the applied voltage and flowing current, strengthen the drive circuit, devise the connection method between the drive circuit and each semiconductor switch element and the wiring method between the main electrodes of each semiconductor switch element, insert a voltage divider circuit, etc. Need of

Therefore, there is a problem that the structure of the main switch becomes complicated and large. Further, as the number of series-parallel semiconductor switch elements increases, the drive power increases and the reliability decreases.

Furthermore, when a semiconductor switch element such as a thyristor is used for the main switch, di /
Watanabe and Kamejima: "Performance improvement example of existing electric equipment dust collector by pulse charging" due to restriction of dt tolerance, pollution and countermeasure Vo
As described in l.25 No.4, pp.349-353 (1989),
The pulse width .tau.1 '+. Tau.2' was limited to several tens .mu.s to 100 .mu.s.

In order to set the pulse width τ1 '+ τ2' to about 10 μs or less, the di / dt resistance is large.
185350 and Yagyu, Yada, Tsuchiya, Tomimatsu, Matsumoto:
"Present state of dust collection technology and development trends", Mitsubishi Heavy Industries Technical Report Vol.2
7 No. 4, pp. 297 to 302 (1990) and the like, use of mechanical switch elements such as rotary gaps and discharge tube switch elements such as thyratrons are being studied. However, the mechanical switching element has a problem that the repetition frequency is limited, the life is remarkably short, and the reliability is low as compared with the semiconductor switching element. In addition, the discharge tube switch element such as thyratron can increase the repetition frequency to the same level as the semiconductor switch element, but like the mechanical switch element, the life of the element is shorter and the reliability is lower than the semiconductor switch element. was there.

Furthermore, Matsui: “Improvement of Performance of Electrostatic Precipitator by Micropulse”, Thermal Power Nuclear Power Vol.41
As described in No.2, pp.92-101 (1990), etc., in the pulse charging type dust collector, the pulse applied to the dust collecting electrode is adjusted according to the dust to be collected and the structure of the dust collecting electrode. It is necessary to optimize the voltage waveform, peak value, pulse width, repetition period, etc. However, said Japanese Patent Publication No. 57-43062
In the pulse precipitator described in No. 6, the pulse width τ1 '+ τ of the pulse voltage superimposed on the precipitator electrode shown in v12' of FIG.
In order to change 3 ', it is necessary to change the synthetic capacitance or synthetic inductance of the pulse generating circuit, and it is difficult to change this easily.

In view of the above, the present invention addresses the above-mentioned problems of the switching element in a pulse generator capable of regenerating an excess of energy supplied to a load, and also determines the pulse width of the pulse voltage supplied to the load. An object is to provide a pulse generation circuit that can be easily changed. Another object of the present invention is to provide a dust collector using such a pulse generator.

[0019]

In order to solve the above problems, the present invention comprises an energy storage capacitor, a main switch for discharging the charge stored in the energy storage capacitor, and a saturable reactor. While supplying energy to the load by the series circuit,
A pulse generator for regenerating the energy supplied to the load from one end of the saturable reactor on the load side to an energy storage capacitor, wherein the energy is supplied to the load.
Is a pulse generator that controls the period of applying the voltage using a magnetic amplifier connected between one end of the saturable reactor on the load side and the energy storage capacitor.

By connecting the main switch and the saturable reactor in series, it is possible to delay the rise of the current flowing between the main electrodes of the main switch when the main switch is turned on. The loss is greatly reduced, and the safe operation of the main switch can be achieved even if the current rising rate di / dt of the pulse current flowing through the main switch is increased. For this reason, when a semiconductor switch element such as a thyristor is used to form the main switch element, the number of semiconductor elements that form the main switch element can be significantly reduced, and reliability is improved, as well as the conventional difficulty. It is also possible to apply a pulse voltage with a short pulse width of about 10 μs or less to the load. When a mechanical switch element such as a rotary gap or a discharge tube switch element such as a thyratron is used for the main switch, the life of the switch element can be significantly extended.

During the energy regeneration, the period during which the energy supplied to the load is applied is set to the operating magnetic flux density amount of the magnetic amplifier connected between the load side end of the saturable reactor and the energy storage capacitor. By making it variable, it is possible to easily change the pulse width of the pulse voltage applied to the load, which could not be changed without changing the capacitance of the capacitor or the inductance of the reactor in the related art.

Further, since the saturable reactor forming the magnetic amplifier can limit the reverse recovery current of the rectifying element forming the magnetic amplifier, the reverse recovery loss of the rectifying element is reduced and the safe operation can be achieved. At the same time, energy regeneration efficiency is also improved.

Further, according to the present invention, a series circuit including an energy storage capacitor, a main switch for discharging the charge stored in the energy storage capacitor, a saturable reactor, and a transformer is provided. A pulse generation circuit that supplies energy to a load and regenerates the energy supplied to the load from the load-side end of the saturable reactor to an energy storage capacitor via the transformer, wherein the load Is a pulse generator that controls the period of applying energy to the load-side end of the saturable reactor by using a magnetic amplifier connected between the energy storage capacitor.

By providing a transformer, a pulse with a high voltage peak value can be output with a low input voltage, and the energy
A switch element having a low withstand voltage can be used as a switch for discharging the electric charge stored in the storage capacitor.

The above-mentioned pulse charging type dust collector using the pulse generator is capable of obtaining a large pulse current of di / dt while achieving a safe operation of the main switch with a simple circuit configuration, and is a load dust collector. While supplying a sharp high-voltage pulse to the electrode, the regeneration circuit works to regenerate most of the energy supplied to the dust collecting electrode to the input side, and at the same time optimize the pulse width of the pulse voltage applied to the dust collecting electrode. Since it can be controlled to a value, high performance, high reliability,
This is preferable because high efficiency and miniaturization can be realized.

[0026]

EXAMPLES Examples of the present invention will be described in detail below, but the present invention is not limited to these examples.

(Embodiment 1) FIG. 1 shows an embodiment of a pulse generator according to the present invention and shows an example of a circuit configuration when applied to a pulse charging type dust collector. The inside of the broken line in FIG. 1 is a pulse generator, and a thyristor 4, which is one of the semiconductor switching elements, is used as a main switch for discharging the electric charge stored in the main capacitor 3 for storing input energy.

In FIG. 1, 1 is an input DC power source of a pulse generator, 2 is a charging resistor for a main capacitor 3, 3 is a main capacitor for storing input energy, and 4 is a charge for discharging the electric charge stored in the main capacitor 3. Is a main switch for the thyristor, 5 is a saturable reactor for reducing the switching loss of the thyristor 4, 18 is a dust collecting electrode 12
A diode constituting a magnetic amplifier for regenerating the excess energy supplied to the main capacitor 3 to the main capacitor 3, 19
Is a saturable reactor constituting a magnetic amplifier, 20 is a main winding of the saturable reactor 19, 21 is a saturable reactor 1
9, control windings 22, 22 and 23 are winding ends of the control winding 21 of the saturable reactor 19, and 8 is a thyristor 4 and a diode 1.
Current rising rate di4 / dt of pulse current flowing through 8
And a reactor for limiting di18 / dt, 9 is a DC power source for applying a DC voltage to the dust collecting electrode 12, 10 is a surge current suppressing reactor, 11 is a DC current blocking capacitor, and 12 is a dust collecting electrode. , 13 and 14 are output terminals of the pulse generator.

In the figure, the positive electrode of the DC power supply 9, the dust collecting electrode 12, the surge current suppressing reactor 10, the DC power supply 9
The DC voltage E9 is constantly applied to the dust collecting electrode 12 with the polarity shown in the drawing through the negative electrode path.

The pulse generator is for superimposing a high voltage like a pulse on the DC voltage E9 applied to the dust collecting electrode 12, and its operation is shown in the circuit configuration of FIG. 1 and the saturable circuit of FIG. An explanation will be given using the operation BH loop conceptual diagram of the reactor 5, the operation BH loop conceptual diagram of the saturable reactor 19 constituting the magnetic amplifier of FIG. 3, and the voltage and current waveforms of the main parts of FIG.

While the thyristor 4 is off, the main capacitor 3 is charged to the voltage E1 with the polarity shown by the input DC power supply 1 through the charging resistor 2. At this time, the operating point of the saturable reactor 5 is at the point a on the operating B-H loop in FIG.

At the time t = 0 in FIG. 4 when the gate signal is input to the thyristor 4 and the thyristor 4 is turned on, the impedance between the main electrodes of the thyristor 4 sharply decreases,
The positive electrode of the main capacitor 3, the dust collecting electrode 12, the DC current blocking capacitor 11, the reactor 8, the saturable reactor 5,
In the negative electrode path of the thyristor 4 and the main capacitor 3, the electric charge accumulated in the main capacitor 3 starts to flow. Therefore, the operating point of the saturable reactor 5 is the operation B-H in FIG.
It changes from point a on the loop to point b. Since the inductance of the saturable reactor 5 during this period is extremely large, the current i4 flowing through the saturable reactor 5 has a very small value, and the switching loss when the thyristor 4 is turned on can be significantly reduced. When the loss is neglected, the saturable reactor 5 blocks the voltage of the peak value E1 having the black circle in the figure as a positive electrode, and becomes as shown by v5 in FIG.

The time τs1 at which the saturable reactor 5 blocks the voltage is set to a value required for the saturation voltage between the main electrodes of the thyristor 4 to be sufficiently small after the thyristor 4 is turned on, and has the following relationship.

[0034]

[Equation 2] N5: Number of turns of the saturable reactor 5 Ae: Effective area of the saturable reactor 5 (m ² ) ΔBm: Operating magnetic flux density amount (T) of the saturable reactor 5 E1: Input DC power supply voltage (V) of the saturable reactor 5 When the operating point reaches the point b on the operation B-H loop in FIG. 2, the saturable reactor 5 is saturated, and the inductance of the saturable reactor 5 sharply decreases,
The current i4 flowing through the saturable reactor 5 is a pulse current having an extremely high di / dt with a peak value of I4 as shown in FIG. 4, but the voltage between the main electrodes of the thyristor 4 is a sufficiently low saturation voltage. The ON loss of the thyristor 4 can be sufficiently suppressed. Therefore, compared to the case where the saturable reactor 5 is not used, safe operation can be achieved even if di / dt is increased several times or more. Further, due to this pulse current, the operating point of the saturable reactor 5 changes from the point b to the point d via the point c.

The pulse width τ1 of the pulse current flowing due to the saturation of the saturable reactor 5 can be approximated by the following equation.

[0036]

[Equation 3] C: Combined value of main capacitor 3 capacity, DC current blocking capacitor 11 capacity and dust collecting electrode 12 capacity (F) L5s: Inductance of saturated saturable reactor 5 after saturation (H) L8: Inductor of reactor 8 ( H) Ls: stray inductance generated by wiring (H) This pulse current is the positive electrode of the main capacitor 3 and the dust collecting electrode 1.
2, the DC current blocking capacitor 11, the inductance 8, the saturable reactor 5, the thyristor 4, the negative electrode of the main capacitor 3 flow, the voltage peak value V shown in v12 of FIG.
Twelve pulse voltages can be superimposed on the dust collecting electrode 12.

Since the dust collecting electrode 12 is a capacitive load, the time t = τs1 + when the charge is completely transferred to the dust collecting electrode 12.
After τ1, the electric charge input to the dust collecting electrode 12 starts to flow in the direction opposite to the direction of the current i8 in FIG. At this time, the operating point of the saturable reactor 19 which constitutes the magnetic amplifier is supplied to the control winding 21 from the reset circuit of FIG. 5 connected to the winding ends 22 and 23 of the control winding 21 of the saturable reactor 19. 3 which is determined by the magnetizing force H1 generated by the reset current I ₂₁ and the magnetizing force determined by the reverse recovery current of the diode 18 from the α point on the B-H loop in FIG.
It changes toward point γ via . In FIG. 5, 3
1 is a variable DC power supply, 32 is a resistor, and 33 is for suppressing surge voltage
Is the reactor of.

The magnetic field applied to the saturable reactor 19 by the reset current I21 is obtained by the following equation.

[Equation 4] N21: Number of turns of control winding 21 of saturable reactor le ': Average magnetic path length of saturable reactor 19 (m)

The operating point of the saturable reactor 19 is from the β point.
Main winding 20 of saturable reactor 19 while changing to γ point
Has a very large inductance, the current i ₁₈ flowing through the main winding 20 of the saturable reactor 19 has a very small value, and the main winding 20 of the saturable reactor 19 has a black circle in FIG. The voltage of the peak value V20 as shown in is blocked.

The time τs2 during which the saturable reactor 19 blocks the voltage has the following relationship.

[Equation 5] N20: Number of turns of the main winding 20 of the saturable reactor 19 Ae ': Effective area of the saturable reactor 19 (m ² ) ΔB1': Operating magnetic flux density amount (T) of the saturable reactor V20: Saturable reactor 19 When the operating point of the saturable reactor 19 reaches the γ point on the operation B-H loop of FIG. 3, the saturable reactor 19 is saturated and the saturable reactor 19 of the saturable reactor 19 The inductance of the main winding 20 drops sharply and the main winding 2 of the saturable reactor 19
The current i ₁₈ flowing through 0 becomes a pulse current having a very high di / dt with a peak value of I ₁₈ , as shown by i ₁₈ in FIG. Due to this pulse current, the operating point of saturable reactor 7 changes from γ point to ε point via δ point.

The pulse width τ2 of the pulse current flowing due to the saturation of the saturable reactor 19 can be approximated by the following equation.

[Equation 6] C: Combined value of the capacity of the main capacitor 3, the capacity of the DC current blocking capacitor 11 and the capacity of the dust collecting electrode 12 (F) L20s: Saturation inductance of the main winding 20 of the saturable reactor 19 (H) L8: Inductance of reactor 8 (H) Ls: Stray inductance generated by wiring (H) This pulse current causes the positive electrode of the dust collecting electrode 12, the main capacitor 3, the diode 18, and the main winding 2 of the saturable reactor 19 to flow.
0, inductance 8, DC current blocking capacitor 1
1. Flow in the path of the negative electrode of the dust collecting electrode 12, and the main capacitor 3
The energy corresponding to the voltage E1 'can be regenerated.

After the time t = τs1 + τ1 + τs2 + τ2 at which the voltage v3 of the main capacitor 3 becomes highest due to the energy regenerated from the dust collecting electrode 12, the main capacitor 3
The electric charges regenerated by the electric field are about to flow to the dust collecting electrode 12 again. However, since the diode 18 is reverse-biased at this time, the diode 18 is cut off after passing a small amount of reverse recovery current, so that the energy regenerated in the main capacitor 3 is almost maintained. Therefore, the energy supplied from the input power source 1 to the main capacitor 3 is
Only the difference between the regenerated voltage E1 'and the input power supply voltage E1 is required.

This reverse recovery current flows through the main winding 20 of the saturable reactor 19 and has the effect of resetting the operating point of the saturable reactor 19 from point ε to point α in FIG. Further, since the peak value of this reverse recovery current is limited by the magnetizing force determined by the operation B-H loop of the saturable reactor 19 shown in FIG. 3, the reverse recovery loss of the diode 18 can be suppressed significantly. Therefore, it also has an effect of allowing a large pulse current of di / dt to flow.

As a result of the above operation, the dust collecting electrode 12 will be
It is possible to superimpose a pulse voltage having a peak value V12 and a pulse width τ1 + τs2 + τ2 indicated by v12.

In this embodiment, the period τs2 from when the pulse current i4 flowing through the thyristor 4 becomes zero until the pulse current starts flowing through the magnetic amplifier composed of the diode 18 and the saturable reactor 19 is the saturable reactor 19. It can be controlled by changing the reset current I21 flowing through the control winding 21 of the above. The larger the value of I21, the longer τs2.
By changing this τs2, the pulse width τ1 + τs2 + τ2 of the pulse voltage superimposed on the dust collecting electrode 12 can be easily changed.

By repeating the same operation hereafter, a small and highly reliable pulse current using a semiconductor switch element can be generated and a large current rising rate di / dt can be generated, and at the same time, the regeneration circuit works. High efficiency can also be realized. Further, a pulse voltage having a pulse width most suitable for the type of dust to be collected and the structure of the dust collecting electrode can be applied to the dust collecting electrode 12, and the dust collecting performance can be improved.

(Embodiment 2) FIG. 6 shows another embodiment of the high-voltage pulse generator according to the present invention, and shows an example of the circuit configuration when applied to a pulse charge type electrostatic precipitator. . The inside of the broken line is a pulse generator. The same parts as those in the first embodiment are designated by the same reference numerals.

The basic operating principle of the pulse generation circuit of this embodiment is the same as that of the first embodiment, and the step-up transformer 1
5 is different in that a high voltage pulse having a peak value higher than the input DC power supply voltage 24 can be applied to the dust collecting electrode 12. That is, after the thyristor 4 is turned on, the saturable reactor 5 is saturated, and the pulse current flowing from the opposite polarity side of the black circle in the drawing of the primary winding 16 of the step-up transformer 15 causes the secondary voltage of the transformer 15 to rise. From the opposite polarity side of the illustrated black circle of the next winding 17, the dust collecting electrode 12,
A pulse current flows in the polarity of the DC current blocking capacitor 11 and the secondary winding 17 on the black circle side in the figure. Due to this pulse current, in addition to the power supply voltage of the input DC power supply 1 which is applied in advance to the dust collecting electrode 12, the step-up transformer 1 has the polarity shown in the figure.
A high voltage pulse having a peak value corresponding to the turns ratio of 5 is superimposed. Since the dust collecting electrode 12 is a capacitive load, after the charge is completely transferred to the dust collecting electrode 12, the charge transferred to the dust collecting electrode 12 becomes a reverse pulse current, and the dust collecting electrode 1
It flows through the positive electrode of 2, the secondary winding 17 of the step-up transformer 15, the DC current blocking capacitor 11, and the negative electrode of the dust collecting electrode 12. Therefore, the main capacitor 3, the diode 18 forming the magnetic amplifier, and the saturable reactor 19 forming the magnetic amplifier are arranged from the reverse polarity side of the black circle in the drawing of the primary winding 16 of the step-up transformer 15.
Of the main winding 20, the reactor 8, the primary winding 16 of the step-up transformer 15 on the polarity side of the black circle in the figure, a pulse current flows,
Energy can be regenerated to the main capacitor 3.

Since the high voltage pulse can be superposed on the dust collecting electrode 12 by using the main switch having a low withstand voltage by using the step-up transformer 15 in combination, the main switch 4 can be configured by using a semiconductor switch element such as a thyristor. In addition, the diode 18 constituting the magnetic amplifier can be of a high-speed type, and high efficiency and high reliability can be achieved.

Further, as in the first embodiment, the step-up transformer 1
When not using 5, the DC power supply 9 for applying a DC voltage to the dust collecting electrode 12 and the input DC power supply 1 of the pulse generator need to be separated, and the power supply voltage of the latter needs to be higher than the power supply voltage of the former. There is a step-up transformer 15 in the pulse generator.
When the dust collecting electrode 1 is provided, as shown in this embodiment,
Since the DC power supply voltage for applying the DC voltage to 2 and the input DC power supply voltage of the pulse generator may be the same, the input DC power supply 1 of the pulse generator is used for applying the DC voltage to the dust collecting electrode 9. Input DC power supply 2 that also serves as DC power supply
It can be used as 4.

(Third Embodiment) In the first and second embodiments, the control winding 21 is connected to the saturable reactor 19 constituting the magnetic amplifier.
However, as shown in FIG. 10, the second control winding 3
It is also possible to provide 1. And this second control winding 3
A preset circuit as shown in FIG. 11 can be added to 1 through the winding tips 32 and 33. The preset circuit shown in FIG. 11 includes an inductance 35, varistor 36 and 41 for absorbing surge voltage, a diode 37, a capacitor 38, a thyristor 39, a resistor 40, and a variable DC power supply 42. With the above-mentioned configuration, the saturable reactor 19 can be driven by the reverse recovery current of the diode 18 that constitutes the magnetic amplifier.
Can be prevented from being unnecessarily reset and narrowing the control range of the magnetic amplifier. That is, if the pulse current supplied from the preset circuit of FIG. 11 is increased, the period τs2 in which the saturable reactor 19 forming the magnetic amplifier blocks the voltage pulse can be reduced.

In the present embodiment, the application example of the present invention to the pulse dust collector has been described, but the same effect can be obtained in the case of another load in which impedance matching between the pulse generating circuit and the load cannot be obtained. It goes without saying that you can get

[0053]

As described above, according to the present invention,
Since the surplus energy supplied to the load can be regenerated to the input energy storage capacitor without passing through the saturable reactor, a highly efficient pulse generator can be obtained and the load pulse can be pulsed depending on the load condition. It is also possible to easily control the period during which the voltage is applied.

In particular, when the high-voltage pulse generator according to the present invention is used in a pulse charge type dust collector, the high performance, high efficiency and reliability, which have been problems in the conventional apparatus, are dramatically improved. Can be improved.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a first embodiment of a high voltage pulse generator according to the present invention.

FIG. 2 is a diagram showing a concept of operating magnetization B-H loop of saturable reactor 5 in FIG.

3 is a diagram showing a concept of an operating magnetization BH loop of a saturable reactor 19 which constitutes the magnetic amplifier of FIG.

4 is a diagram showing voltage and current waveforms of main parts in the circuit of FIG.

5 is a circuit diagram showing a configuration of a reset circuit of a saturable reactor 19 which constitutes the magnetic amplifier of FIG.

FIG. 6 is a circuit diagram showing a second embodiment of the high voltage pulse generator according to the present invention.

FIG. 7 is a diagram showing a circuit disclosed in Japanese Patent Publication No. 57-43067.

8 is a diagram showing voltage and current waveforms of main parts in the circuit of FIG.

9 is a diagram showing voltage waveforms of a dust collecting electrode and an energy-storing main capacitor in the circuit of FIG. 7.

FIG. 10 is a circuit diagram showing a third embodiment of the high voltage pulse generator according to the present invention.

11 is a circuit diagram showing a configuration of a preset circuit of saturable reactor 19 which constitutes the magnetic amplifier of FIG.

[Explanation of symbols]

1 input DC power supply, 3 input energy storage capacitor, 4 semiconductor switch element, 5 saturable reactor,
8 reactor, 9 DC power supply, 10 surge current blocking reactor, 11 DC current blocking capacitor, 12
Dust collecting electrode, 15 step-up transformer, 16 step-up transformer 15
Primary winding, 17 secondary winding of step-up transformer 15, 18
Diodes constituting a magnetic amplifier, 19 Saturable reactor constituting a magnetic amplifier, 20 Main winding of saturable reactor 19, 21 Control winding of saturable reactor 19, 24 input DC power supply, 25 diode, 31 Saturable reactor 19 Second control winding

Claims (3)

(57) [Claims] 1. A series circuit composed of an energy storage capacitor, a main switch for discharging charges accumulated in the energy storage capacitor, and a saturable reactor supplies energy to a load, and A pulse generator for regenerating the energy supplied to the load from one end of the saturable reactor on the load side to an energy storage capacitor, wherein a period for applying energy to the load is applied to the load side of the saturable reactor. A pulse generator controlled by using a magnetic amplifier connected between one end of the energy storage capacitor and the energy storage capacitor. 2. An energy storage capacitor, a main switch for discharging the charge stored in the energy storage capacitor, a saturable reactor, and a series circuit composed of a transformer to supply energy to a load. A pulse generator that supplies the energy supplied to the load from the load-side end of the saturable reactor to the energy storage capacitor via the transformer, and supplies the energy to the load. Is controlled by using a magnetic amplifier connected between one end on the load side of the saturable reactor and the energy storage capacitor. 3. A pulse charging type dust collecting apparatus, wherein the load is a dust collecting electrode using the pulse generating apparatus according to claim 1 or 2.