JPS6111549B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is a pulse power supply that makes it possible to supply a steep pulse voltage with low power loss to a load having a capacitance or a high resistance connected in parallel to a capacitance (hereinafter referred to as a capacitive load). It is related to. When applying a pulse voltage to a capacitive load using a conventional pulse power supply, (1) an extremely large charging current is required to make the rise steep; therefore, the output impedance of the power supply is extremely small and instantaneously large; (2) In order to make the fall steep, the pulse voltage V is required.
By applying [V], the capacitance C of the capacitive load is
In order to rapidly discharge the charge CV [C] charged in [F], it has been required to connect a sufficiently low discharge resistance in parallel to the capacitor section. However, (1) above requires an excessive instantaneous output capacity for the pulse power supply, making its price excessive, and (2) requires a large current to flow through the low resistance each time a pulse is applied, resulting in excessive unit loss. In addition, it is necessary to cause the energy (1/2) CV ² [J] stored in the capacitance C to be consumed as heat by the resistor after the pulse applied voltage disappears, so that the pulse power actually consumed by the load itself is The major drawback was that the power loss was excessive compared to the conventional method. The object of the invention is to overcome the above-mentioned drawbacks and to provide a pulsed power supply which makes it possible to supply all types of capacitive loads with extremely steep pulsed voltages with significantly lower power losses. be. However, in the present invention, the above object is achieved by (a) using a DC power supply to connect a power supply capacitor having a sufficiently large capacitance C' compared to the capacitance C of the load capacitor to approximately 1/1/2 of the required pulse peak value V; (b) This is charged to a voltage V′ with a value of 2, and (b) this is charged by a suitable switch element S (for example, a silicon-controlled rectifier, a two-way three-terminal thyristor (triax), a switching discharge tube, a rotary switch, etc.). , and connected to the capacitive load via conductors of suitable series inductance and significantly low resistance, thereby generating very poorly damped transient oscillations, so that the electrostatic capacitance of the capacitive load is Immediately after charging the capacitance C to approximately twice V', that is, V, the switch element S
(c) Then, after a time τ [S] corresponding to a predetermined pulse width, another switch element S' connected in antiparallel to the above switch element S brings the voltage to a value near V. The charged capacitive load is passed through the series inductance and the low resistance wire to V′=
By reconnecting the power supply capacitor, which is charged to a voltage of (1/2) V, the resulting similarly very poorly damped transient oscillation removes most of the charge stored in the load capacitor. power capacitor
At the same time, the voltage across the load capacitor is reduced to an extremely small value V'' (it is impossible to reduce this value to 0 for reasons explained later), and immediately after that, the switch element S' is turned on. Cut the
(d) Next, both ends of the capacitive load are short-circuited via another switch element S'', and the residual charge CV is discharged to return the voltage across the capacitive load to the initial value 0, and immediately after that, This is achieved by cutting off the conduction of the switch element S''. In this case, if the voltage across the capacitive load is not returned to its initial value of 0, the residual voltage will gradually approach V' and the peak value of the pulse voltage appearing across the load will also approach V' from 2V'.
As will be described later, it will eventually become impossible to generate a pulse voltage using this method. In addition, inductance always exists in the discharge circuit including the capacitive load and the switch element S'' (especially when using a silicon-controlled rectifier, a protective inductance is inserted to suppress di/dt), so if The load capacitor is charged to the opposite polarity.To prevent this, a rectifier G (flywheel rectifier) is installed in parallel with the capacitive load, with a rectifying direction that prevents the load capacitor from being charged by the power supply. element), and the charging current in the opposite direction must be cyclically attenuated through G. In other words, the pulse power supply of the present invention has a capacitance that is sufficiently large compared to the capacitance C of the load capacitor.
A power supply capacitor with voltage C', a DC power supply connected to both ends A and A' of the power supply capacitor via a suitable charging impedance (resistance or inductance) to charge it to voltage V', and the power supply capacitor. A suitable load charging switch element S for opening and closing the connection between the power supply capacitor connected to one end A and the load, and a pulse to the load connected to the other end of the switch element S. An output terminal B for supplying voltage, an inductance for generating transient vibrations connected in series to the path from terminal A to B, and another output connected to the other end A' of the power supply capacitor. Another suitable load capacitance charge recovery switch element S' is connected in anti-parallel with the switch element S between terminal B' and A and B, and is connected between the output terminals B and B'. Another switch element S'' for discharging the residual charge of the load capacitance for opening and closing the connection of A rectifying element G for preventing reverse charging of load capacitance connected with a rectifying direction to prevent this.
and the switch elements S, S′, S″ are changed from S→S′→
In the order of S″→S→S′→S″, the pulse width τ, the minute time ′ which is slightly larger than the half cycle of vibration of the power supply capacitor-the inductance-the load capacitor circuit, and the pulse pause time T′. It has a control unit that closes the circuits sequentially at time intervals, and thereby opens and closes the switch elements S, S', S'', and first closes the switch element S, thereby charging it to voltage V' in advance. A power supply capacitor connected to the load, which generates extremely poorly damped transient vibrations, increases the capacitance C of the load capacitor.
After charging to a voltage V approximately twice that of V', S is opened, and then the switch element S' is closed after a time period of the required pulse width τ, thereby charging the power supply capacitor to a higher voltage again. After connecting a load, most of the charge stored in the load capacitor is recovered to the power supply capacitor by the transient oscillation with very little damping that occurs, S' is opened, and immediately after that, the switch is connected. By closing element S'', the charge remaining in the load capacitor without being recovered is discharged, and B→S''→B'→G→
After attenuating it as a circulating current in the closed circuit of B and returning the residual voltage of the load capacitor to 0, S'' is opened, supplying a steep pulse voltage to the capacitive load, and draining the energy stored in the load capacitor. As a result of the above-mentioned features, the pulse power supply of the present invention has an extremely short rise time corresponding to a half cycle of the above-mentioned transient oscillation for a capacitive load. has,
In addition to being able to apply steep pulse voltages, the energy stored in the load capacitance is effectively recovered to the power source, significantly reducing power loss, and maintaining high efficiency of approximately 80%. It achieves remarkable effects that were completely impossible with conventional pulse power sources. The switch elements S, S', S'' used in the pulse power supply according to the present invention include silicon controlled rectifier elements,
Although any switching element such as a 2-way 3-terminal thyristor (triax), a switching discharge tube, a rotary switch, a power transistor, etc. may be used, it is particularly preferable to use a silicon-controlled rectifying element, and in this case, the above-mentioned S . By using an appropriate element such as a triax or rotary switch, or by using it in combination with an appropriate circuit element (for example, a bridge-connected rectifier) as shown in the examples below, it can be connected in antiparallel to this. It can also serve as the function of the switch element S', which makes it possible to omit S'.In addition, in the present invention, the residual charge that remains after the charge of the load capacitor is recovered to the power supply capacitor is may be directly discharged by short-circuiting the terminals B and B' by closing the switch element S'' as described above, but this may also be collected in the power supply capacitor by the following method. In other words, a regenerative transformer is used, its primary winding is connected to the output terminals B and B' via the above-mentioned switch element S'', and its secondary winding is connected to the output terminals B and B' through the switch element S'', and the secondary winding is connected to the The winding is connected to both ends A and A' of the power supply capacitor via a discharge prevention rectifying element G' (the rectification direction is a direction that prevents the voltage of the power supply capacitor from discharging).This causes the switch element to When S'' is closed, a discharge current flows through the primary winding of the regenerative transformer due to the residual voltage of the load capacitor, and correspondingly, a secondary current flows through the secondary winding to the power supply capacitor. Eventually, even more of the residual charge will be recovered to the power supply capacitor. By doing so, the power loss can be further reduced and the efficiency can be increased to over 90%. As the regenerative transformer, it goes without saying that in addition to a normal transformer, an autotransformer or a pulse transformer may be used. In addition, in the present invention, the required pulse repetition period T
When =τ+′+T′ is sufficiently long compared to the time constant of the load, insert an appropriate inductance in place of S″ above and discharge the residual charge in the load capacitance through the inductance, or It is also possible to omit the above S'' and G and discharge the residual charge in the load capacitor via the load resistor. The pulse power supply of the present invention can be used to supply a steep pulse voltage to various capacitive loads having large capacitance, but especially to both electrodes of an electrostatic precipitator equipped with a discharge electrode and a dust collection electrode. In between, it can be used to apply a steep and periodic high-voltage pulse voltage superimposed on the DC voltage, or it can have a discharge electrode, a dust collection electrode, and a third electrode, and between the third electrode and the dust collection electrode. An electrostatic precipitator with a third electrode that applies a DC voltage for forming the main electric field and a pulse voltage between the discharge electrode and the third electrode (e.g.
The connection between the discharge electrode and the third electrode of Patent Application No. 091188 of 1972 (Japanese Unexamined Patent Publication No. 50-38869, Japanese Patent Publication No. 60-33543) "Pulse charging type two-stage electrostatic precipitator" filed on the 14th It is suitable for use in applying a steep and periodic pulse voltage directly or superimposed on an auxiliary DC voltage (bias voltage) between the two. However, in these usage examples, when applying a pulse voltage in addition to a DC voltage, it is recommended that a suitable wave circuit including a capacitor for bypassing the pulse voltage be connected in parallel to the DC voltage power supply. . DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration and features of the pulse power source of the present invention will be explained in detail below with reference to drawings and examples. FIG. 1 is a circuit diagram showing the principle of construction of the pulse power source of the present invention. FIG. 2 is a diagram showing the waveforms of its output pulse voltage v and output pulse current i. In Figure 1, 1
is a power supply capacitor having a capacitance C' [F], 2 is a DC power supply for charging this, and is a rectifier connected to the rectifier transformer 3 and its secondary winding (in this example, the rectifier is bridge-connected). One output terminal D (positive polarity in this example) is connected to one end A of the power supply capacitor 1 via a conductor 5 and a current limiting impedance (inductance or resistance) 6. It is connected to the. Another output terminal D' of the rectifier is connected to the other end A' of the capacitor 1 via a conductor 5'. Terminal A is connected to the output terminal B of the pulse power supply via a low-resistance conductor 7, a silicon-controlled rectifier S as a load charging switch element, and an inductance 54 for generating transient vibrations, and the other end A' is a low-resistance conductor. is connected to another output terminal B' of the pulse power supply via a conductor 7'. S' is a silicon-controlled rectifier element connected in antiparallel with S as another switch element for recovering load capacitance charge, S'' is a protective inductance l, and the output terminal B is connected through a low resistance conductor 8. A silicon-controlled rectifier element as another switch element for discharging the residual charge of the load capacitance is connected between B', and G is connected between the output terminals S''-
A rectifying element (flywheel rectifying element) for preventing load reverse charging is connected in antiparallel to l by a low resistance conductor 8'. However, the rectifying directions of the silicon-controlled rectifying elements S, S', and S'' are A→B, B→A, and B→B' in this example, and the rectifying direction of the rectifying element G is as follows in this example. 9 is a control section for silicon-controlled rectifying elements S, S', S'', and its output terminals 10, 11, 12 are connected to S via conducting wires 13, 14, 15, respectively. ,S′,
Connected to gate terminals 16, 17, 18 of S'',
A control pulse voltage is supplied to this. Output terminal B,
B' is a capacitive load 21 represented by a parallel connection of a load capacitor 19 having a capacitance C [F] and a resistor 20 having an extremely large resistance value R [Ω].
are connected via low resistance conductive wires 22, 22'. In addition, in FIG. 2, the curve v is the output pulse voltage v applied from the output terminals B and B' to the capacitive load 21.
The waveform of (B is taken to be positive with respect to B'), the curve i is the waveform of the output pulse current i (the direction of B→21 is taken to be positive) supplied from the output terminals B and B' to the load 21. show. Now, the required output peak voltage of this pulse power supply is V
[V], the required pulse width is τ [S], and the required pulse pause time is T' [S], as described above, the repetition period is T=τ+'+T' [S]. On the other hand, the DC output voltage of the DC power supply 2, and therefore the terminal voltage of the power supply capacitor 1, is selected to be approximately V' = (1/2) V, the circuit resistance including the conductor wire is made sufficiently small, and the inductance is By appropriately selecting the value of L in 54, S
If a transient vibration with very little damping is generated when the circuit is closed, the load capacitor 19 can be charged to approximately V=2V' as described later. However, the capacitance C' of the power supply capacitor is set to be sufficiently large compared to the capacitance C of the load (C'>>C). In order to achieve the above purpose, the transient vibration inductance 54 must be
The value of is (i) |-A-7-S-54-B-22-19
If the circuit resistance of -22'-B'-7'-A' is r [Ω], then the values of L, C, and r must be selected so that when S is closed, the circuit simply vibrates. Not only that, but the transient oscillations charge the load capacitor 19 to a limit as close to twice V' as possible, and when S' is closed, the transient oscillations discharge the residual charge of the load capacitor 19. It is necessary to choose so that as much as possible can be recovered into the power supply capacitor. For this purpose, as described below, in order to suppress the voltage attenuation in the half cycle of vibration as much as possible, L/C≫
It is necessary to satisfy the condition ^r2 . (ii) A second requirement for the inductance 54 is that it has the function of keeping the current and di/dt of the silicon-controlled rectifying elements S, S' below permissible values. Therefore, the value of L needs to have a value sufficient to satisfy these requirements. (iii) However, within that range, by selecting L as small as possible, the rise and fall times of the pulse voltage ≒ π√
Needless to say, it is necessary to reduce [S]. In addition, the value of the protective inductance l needs to be sufficient to keep the current and di/dt of the silicon-controlled rectifier S″ below the allowable value, but within that range it should be selected as small as possible to avoid any residual charge. It is better to reduce the time constant of current decay during discharge.
The control section 9 first supplies a control pulse voltage from its output terminal 10 to the gate terminal 16 of the silicon-controlled commutator S, and then supplies a control pulse voltage for a time τ [S] corresponding to the pulse width.
Later from its output terminal 11 a silicon controlled commutator
Supplying a control pulse voltage to the gate terminal 17 of S′,
Immediately after that (more precisely, after a period of time slightly larger than the above-mentioned time [S]), a control pulse voltage is supplied from the output terminal 12 to the gate terminal 18 of the silicon-controlled commutator S'', and then the pulse rest period is
After T' [S], a pulse control voltage is again supplied from the output terminal 10 to the gate terminal 16 of S, and the above-described operation is repeated. Accordingly, in the next operation of the circuit of this example, a periodic pulse voltage is supplied to the load and charge is regenerated to the power source. That is, at the moment when a control pulse voltage is applied to the gate terminal 16 of the silicon-controlled rectifying element S, S is turned on, thereby causing the terminals A of the power supply capacitor 1,
A′ to conductor 7, 7′ transient vibration inductance 5
4. A charging current flows to the load capacitor 9 of the load 21 via the output terminals B, B' and the conductors 7, 7', the transient vibration inductance 54, the output terminals B, B', and the conductors 22, 22'. The charging current i associated with this
[A] and the terminal voltage v of the load capacitor 19
Elapsed time t from the turn-on of [V]
Changes to [S] should be made so that the above-mentioned circuit resistance γ is sufficiently small, the value of L is appropriate, and the vibration condition 1/L (1/C + 1/C') > (γ/2L) ² is satisfied. The result is a damped vibration, as shown in the following equations. The waveforms of v and i are as shown in Figure 2, and both are t = 0.
V increases with time, and due to the load capacitor, transient vibration inductance, and transient vibration phenomenon,
When the differential value of v is maximum on the curve from the position to the highest position α, the value of i is approximately maximum,
Also, when the differential value of v is 0 (at the position of α), the value of i becomes 0. In this way, at the time of t=t ₁ =2/ω _p , i=0, and the silicon-controlled rectifier S′ For B
→A voltage is applied and turns off. The value of the terminal voltage of the load capacitor 19 at this time is as follows. v ₁ = V _p (1-e ^-t ₁ ^/ 〓 ^o cos2) (4) Here, in order to make the value of the pulse voltage v ₁ as large as possible, as is clear from equation (3), C′≫C. At this time, V _p ≒V'. In order to speed up the rise of the pulse voltage, it is necessary to increase ω _p as much as possible, and for this purpose, as is clear from equation (3), 1/LC≫(γ/2L)
² , that is, L/C≫γ ² In other words, it is necessary to select γ small. At this time, ω _p ≒1/√. In this case, as is also clear from equation (3),

[Formula] becomes. The time when this current becomes 0 is t ₁ ≒ π/ω
_p , which is approximately equal to the half period of the transient oscillation ≒ π√. The pulse voltage value v ₁ at this time is calculated from equation (4) and
v ₁ = V'(1+e ^- 〓 ^/ 〓 ^o ). Therefore, in order to increase v ₁ as much as possible, in order to further suppress the attenuation after half a period of vibration, /τ _p = π√
LC/2L/γ≫1, that is, L/ ^C≫γ2. In other words, it is necessary to select a sufficient value of τ _p =2L/γ for a given C. As a result, v ₁ ≒2V′. di/dt required for silicon controlled rectifier S
In order to satisfy the condition, the value of L must be at least t ₁ =
It is necessary to select such that =π√ is greater than a predetermined value. Furthermore, in order to suppress the current value required for the silicon-controlled rectifying element S to a required value, it is necessary to set the value of L to at least a certain value or more, as is clear from i _p in equation (3). Furthermore, the instantaneous silicon-controlled rectifier S when i=0
As mentioned above, a voltage of approximately 2V'-V'=V' is applied to the series connection of the inductance 54 in the opposite direction (B→A direction), so in reality, as shown in _FIG. A reverse current flows as shown by the curve between t ₁ and t ₂ until the carriers remaining inside the silicon-controlled rectifying element S completely disappear even after t ₂ . The controlled rectifier S is completely turned off. Correspondingly, the voltage v is
It is held only after passing the peak value α corresponding to v ₁ ≒ 2V′ and reaching β corresponding to a value v ₂ slightly smaller than 2V′, and after that, the time constant CR with a large load is applied.
It decays very slowly depending on the Next, at time _t3 (at this time, S is of course turned off), a control pulse voltage is applied to the gate terminal 17 of the silicon-controlled rectifier S'. At this moment, S′ turns on, and this time
The voltage v ₃ is slightly smaller than 2V′ (needless to say, v ₃ <
_A current i flows from load capacitor 19 at voltage V' to power supply capacitor 1 through transient vibration inductance 54 from t ₃ to t ₄ in FIG.
An oscillating current i flows like a curve, and a considerable portion of the charge stored in the load capacitor 19 is recovered to the power supply capacitor 1 along with this. Voltage at this time v
The waveform is as shown in the curve from γ to δ. When the elapsed time from time t ₃ is t, the temporal change in voltage v ₁ and current i during this time is as shown in the following equation. v≒V′+(v ₃ −V′) cosω _p t (5) i=−i _p ′sinω _p t (6) However

[Equation] The other quantities are as given in Equation (3). That is, half period of transient oscillation from time t ₃ = π√
At the time t ₄ , the current i becomes 0, S′ is turned off, and the voltage v becomes the minimum value v ₄ =
The δ point corresponding to 2V′−v ₃ is reached. In fact, as already mentioned, after turn-off, the reverse current flows until the residual carriers in the silicon-controlled rectifier S disappear, so that v rises again from v ₄ , and at the point in time
At t ₅ , the reverse current stops, v is held at the η point corresponding to v ₅ (v ₅ >v ₄ ), and a corresponding charge remains in the load capacitor 19 . Immediately thereafter (time t ₆ ), a control pulse voltage is applied to the gate terminal 18 of the silicon-controlled rectifier S'' (at this time, needless to say, S' is turned off), so that S'' is turned off. When the load capacitor 19 is turned on, the charge Cv ₅ remaining in the load capacitor 19 is discharged through S'' and the protective inductance l, and the voltage v and current i change over time as shown in Figure 2 and become 0. In this case, the moment the voltage v becomes 0 (time t ₇ ), the current i takes the maximum negative value, but at this instant it moves to the rectifier G for preventing reverse charging, becomes a circulating current, and the reverse current of the load capacitor 19 flows. Charging to the polarity is prevented, and the current attenuates over time due to joule loss due to resistance in the circulation path, finally reaching 0. Through the above process, approximately 80% of the energy supplied to the load capacitor is regenerated to the power supply. _{It has been experimentally} confirmed that Connect a pair of diagonal points of circuit 23 to terminal A
This is an embodiment in which the silicon control element S is connected between the inductance 54 and the inductance 54, and is inserted between another pair of diagonal points, thereby also serving as S'. Therefore, S' is omitted. Further, the terminal 17 for supplying a control pulse voltage to the gate of S' in FIG. 1 is connected to the gate of S by a conductive wire common to the terminal 16 in this example, as shown. In addition, the rectifying direction of the pair of rectifiers G' ₁ and G' ₃ in the Bridge rectifier circuit is A→
B, the rectifying direction of the other pair of rectifiers G' ₂ and G' ₄ is B←
It is in the direction of A. The names and functions of other requests represented by numbers and letters from 1 to 22' are exactly the same as those of the names with the same numbers and letters in FIG. Now, when a control pulse voltage is supplied from the output terminal 10 of the control section 9 to the gate terminal 16 of S, S turns on and the power supply capacitor 1 to 1→7→G' ₁ →S→G' ₃ →54→B→ 22
An oscillatory charging current i flows along the path →19→22'→7'→1, and the voltage v across the load capacitor 19 is charged to a voltage nearly twice the voltage V' of the power supply capacitor 1. S turns off. The temporal changes in i and v during this time are exactly the same as in the case of FIG. 1, and are represented by the changes between 0 → t ₁ → t ₂ in FIG. Next, after a time τ [S], the control unit 9
When a control pulse voltage is supplied from the output terminal 11 to the gate terminal 17 of S, S is turned on again, but at this time the terminal voltage of the load capacitor 19 is
Since it is close to 2V' and higher than the terminal voltage V' of the power supply capacitor, from the former to the latter, 19 → 22 → B →
54→G' ₄ →S→G' ₂ →7→A→1→7'→B'→2
An oscillatory discharge current i flows along the path 2'→19, the voltage v across the load capacitor drops to a value close to 0, and S is turned off again. The temporal changes in i and v during this time are also the same as in the case of FIG. 1, and are represented by the changes between t ₃ →t ₄ →t ₅ in FIG. All operations and temporal changes in i and v during the period t ₅ -> t ₆ -> t ₇ are exactly the same as in the case of FIG. 1, and are as shown in FIG. 2, so the explanation thereof will be omitted. Fig. 4 is a circuit diagram of an embodiment in which a rectifier G'' is used in place of the silicon-controlled rectifier S' in the embodiment shown in Fig. 1, and Fig. 5 shows the waveforms of the output pulse voltage v and output pulse current i. In Fig. 4, l' is an inductance inserted in series with G'' and in parallel with S, and has the effect of ensuring that S turns off. The names and functions of the other elements represented by numbers and letters from 1 to 22' in FIG. 4 are exactly the same as those of the elements represented by the same numbers and letters in FIG. The curve v in FIG. 5 represents the output pulse voltage (B) applied from the output terminals B and B' to the capacitive load
The curve i is the waveform of the output pulse current i (the direction of B→21 is positive) supplied from the output terminals B and B' to the load 21. The changes in v and i up to time t ₁ as the silicon-controlled rectifier S is turned on in FIG. 5 are also the same as in FIG. 2. However, in this example, the current i becomes 0 at time _t1 , and after that, a reverse voltage of V' is applied in the direction of B→A, and a reverse current starts to flow through G'', but a rectifier is connected in parallel to S.
G″ is included, so if l′ is not present, turn to S.
No reverse voltage is applied to turn it off, and all reverse voltage on V' is shared by 54. Only by inserting l' can a reverse voltage necessary for turning off S be applied for the necessary time, and S will be turned off reliably. This discharge current flowing through G'' immediately causes the load capacitor 19 to
The charge recovery begins, and the subsequent changes in v and i are as shown in Figure 5. At time t ₂ , half a cycle of vibration after t ₁ , the current i returns to 0, and v reaches a minimum value close to 0. Takes a value. After that, current flows in the positive direction for a short time through the apparent capacitance of G'', that is, while the carrier in G'' disappears, so v increases slightly,
At time _t3 , i becomes 0, and v is held at the value at that time. The load capacitor 19 associated with this
The operation of discharging the residual charge by S'' is the first step.
Similar to the case shown in the figure, the temporal changes in v and i at that time are exactly the same as the changes in v and i after time t ₆ in FIG. The pulse voltage obtained by this method is a pulsating pulse with a half-width of approximately 2 V' and a peak value of 2 V'.
Although the square wave pulse with the predetermined pulse width τ obtained by the methods shown in Figures 1 and 3 will not be obtained, S'
The economical effect of being able to substitute G'' is great, and there are many applications in which such a waveform is sufficient to achieve the desired purpose. This is a circuit diagram of an example in which high-order generation is implemented. That is, a silicon-controlled rectifier element is used as a switch element for discharging residual charge in a load capacitance.
1 of the already mentioned regeneration transformer 24 in series with S''.
One end of the secondary winding 25 is connected by a low resistance conductor 26, the other end is connected to the output terminal B' by a low resistance conductor 26', and the secondary winding 27 ( The number of turns of the primary winding is sufficiently increased compared to the number of turns of the primary winding. The other end of the secondary winding 27 is connected to the other end A' of the power supply capacitor 1 via a low resistance conductor 28'. This causes the residual charge Cv ₅ of the load capacitor 19 at time t ₅ shown in FIG. 2 to be discharged through the primary winding 25 by turning on S'', thereby causing the Generate an electromotive force sufficiently higher than V' in the next winding 27, 27→G→28→1→2
By allowing the secondary current to flow into the power supply capacitor 1 through the path 8'→27, most of the residual energy (1/2) Cv ₅ ² of the load capacitance can be regenerated into the power supply capacitor 1. It has been demonstrated that power efficiency can be increased to over 90%. In this embodiment, with the inductance of the primary winding 25, the protective inductance l in FIG.
l can be substituted, so l is omitted. In addition, the names and functions of the elements numbered 1 to 22' and the elements represented by letters in the figure are exactly the same as those of the elements with the same numbers and the same letters in Fig. The operation is the same as in Figure 1. Figures 7 and 8 are examples in which the above-mentioned regenerative transformer 24 is used in the embodiments shown in Figures 3 and 4, respectively, and the method of use and operation thereof are exactly the same as in the case of Figure 6. Since this is obvious from the figure, its explanation will be omitted. In the embodiments shown in FIGS. 1 to 8, silicon-controlled rectifiers S, S', S'' as switch elements, rectifiers 4, G, G' ₁ to G' ₄ , G'', G
are all shown as one element, but as the required pulse voltage becomes higher, it goes without saying that the required number of these elements can be connected in series, and in this case, the voltage of each element Add an appropriate voltage divider circuit to improve the sharing,
It is obvious that the ignition of S to S'' can be easily performed using an appropriate method. It is also possible to increase the pulse output current by connecting these elements in parallel, if necessary. FIG. 9 shows that the novel pulse power supply device according to the present invention is connected in series to a known DC high voltage power supply, and a negative DC high voltage is applied to the discharge electrode of an electrostatic precipitator consisting of a discharge electrode and a dust collecting electrode. This is an embodiment of the present invention that is used to apply a steep negative pulse voltage.
In this case, the electrostatic precipitator has a high parallel resistance corresponding to capacitance and corona discharge between the discharge electrode and the dust collection electrode, and is a typical capacitive load. 29 is a pulse power source of the present invention including those illustrated in FIGS. 1, 3, 4, 6, 7, and 8; however, in this example, a negative pulse voltage is used. As a result, the first
Silicon-controlled rectifying elements S, S', S'' and rectifiers 4, G, G' ₁ , G' ₂ ,
The forward directions of G′ ₃ , G′ ₄ , G″, G, etc. are all reversely connected. 30 is the electrostatic precipitator main body, 3
1 is the dust-containing gas inlet, 32 is the clean gas outlet, 33 is the dust collection electrode grounded together with the main body, 3
Reference numeral 4 denotes a group of discharge electrodes for performing corona discharge supported by insulation. 35 is a step-up transformer 36 and a rectifier 37
A negative DC high voltage power supply with output terminals J,
The positive terminal J' in J' is grounded. The output terminals J, J' are connected to capacitors 38, 38', 3
Pulse voltage bypass wave circuit 40 consisting of a T-type connection of 8″, …… and impedance (resistance or inductance) 39, 39′, 39″, ……
The output terminal E is connected to the positive output terminal of the negative pulse power supply 29 via the low resistance conductor 41.
B' and supplies it with a negative DC voltage with respect to ground. However, 42 is the capacitor 38,3
8', 38''...... is a high resistance for discharging residual charges.The negative output terminal B of the negative pulse power source 29 is connected to the discharge electrode group 3 via a low resistance conductor 43 and a porcelain tube 44.
Connected to 4. As a result, the discharge electrode group 34 receives a periodic negative pulse high voltage (supplied by the pulse power supply 29) with an extremely steep and short pulse width, superimposed on the negative DC voltage (supplied by the DC power supply 35) just before the spark flash path. A superimposed voltage is applied. In this case, since the spark voltage caused by such a pulse voltage is extremely high, the peak voltage of the applied voltage can be significantly increased, and the suspended particles in the gas introduced from the inlet 31 have a significantly high charge (peak voltage). (proportional to the head voltage), it is possible to remove dust extremely effectively. The role of the wave circuit 40 is to bypass the pulse voltage generated by the wave circuit 29 and prevent it from affecting the DC power supply 35.
Otherwise, the pulse voltage would overlap with the step-up transformer secondary voltage, causing a large change in the voltage between J and J', and the operation of the entire power supply would not be normal. FIG. 10 shows a pulse power source 29 of the present invention used in an electrostatic precipitator with a third electrode, which has a discharge electrode, a dust collection electrode, and a third electrode provided near the discharge electrode. An embodiment will be described in which a negative pulsed high voltage is applied superimposed on a positive DC high voltage for bias application between the discharge electrode and the discharge electrode. In the figure, 29 is a negative high voltage pulse power supply of the present invention, 35
is a positive DC high-voltage power supply for providing DC bias, and 40 is a wave circuit connected to this to bypass pulse voltage; the names and functions of elements numbered 3 to 44 in the figure are the same as in Figure 9. It is the same as that of the numbered element. 45 is provided near the discharge electrode 34, and is connected to the dust collection electrode 33.
The third electrode is insulated and supported from both sides of the discharge electrode, and in this example, it consists of channel-shaped electrodes provided symmetrically on both sides of the discharge electrode. 46 is a negative DC high voltage power supply for forming the main electric field, which is composed of a step-up transformer 47, a rectifier 48, a smoothing capacitor 49, and a charging impedance 50, and F and F' are its terminals, among which the positive terminal F' is grounded. Also, the negative polarity terminal F
is connected to the third electrode 45 via a low-resistance conductor 51 and an insulator tube 52, and a dust collecting electrode 33 is connected to the third electrode 45 and grounded.
A main electric field for collecting charged dust is formed between the two and the former with negative polarity. Furthermore, F is connected to the negative polarity output terminal E' of the wave circuit 40 via the low resistance conductor 53, and its positive polarity output terminal E is connected to the low resistance conductor 41.
is connected to the positive output terminal B' of the negative high voltage pulse power source of the present invention, and the negative output terminal B is connected to the discharge electrode 34 through a low resistance conductor 43 and a porcelain tube 44. As a result, between the third electrode 45 and the discharge electrode 34, a positive DC bias high voltage and a periodic negative steep pulse voltage are applied from the former toward the latter, Each time, a negative ion current is supplied from the discharge electrode 34 toward the dust collecting electrode 33 in a pulsed manner. This negative ion current has an extremely high density and is composed of a negative ion cloud with extremely good dispersion due to its strong Coulomb repulsion, forming a uniform current distribution on the dust collection pole, and the current density is always above the level above. While keeping the main electric field at its highest,
Since it can be freely controlled by changing the peak value of the pulse voltage, its repetition frequency, the value of the DC bias voltage, etc., it is possible to prevent reverse ionization when the electrical resistance of the dust is extremely high, or to prevent the dust concentration from becoming extremely high. It can completely overcome the corona blocking effect at high temperatures and always maintain the best dust collection performance. The bias power supply 35 maintains the potential of the tip of the discharge electrode 34 at an intermediate potential between the third electrode 45 and the dust collecting electrode 33 when the pulse voltage is stopped, thereby causing a DC negative voltage to flow from the tip when the pulse voltage is stopped. This is to prevent corona discharge from occurring and to ensure that corona discharge is always performed in a pulsed manner.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of an embodiment of the present invention, and FIG. 2 is a diagram showing the waveforms of the output pulse current and output pulse voltage. 3 and 4 are circuit diagrams of other embodiments of the present invention, respectively, and FIG. 5 is a waveform diagram of the output pulse current and output pulse voltage of the embodiment of FIG. 4. FIGS. 6, 7, and 8 are circuit diagrams of still other embodiments of the present invention. FIG. 9 and FIG. 10 each show an embodiment in which the pulse power source according to the present invention is utilized in an electrostatic precipitator. 1...Power supply capacitor, 2...DC power supply, S,
S′, S″……Silicon controlled rectifier, G, G′ ₁ ,
G' ₂ , G' ₃ , G' ₄ , G'', G... Rectifier, L, l,
l'...Inductance, 9...Silicon controlled rectifier control section, 19...Load capacitor, 20...
Load resistance, 24... Regeneration transformer, 29... Pulse high voltage power supply, 30... Electrostatic precipitator body, 33
... Dust collection electrode, 34 ... Discharge electrode, 35, 46, 5
6, 59...DC high voltage power supply, 40...wave circuit,
45...Third electrode.

Claims (1)

[Scope of Claims] 1. A power supply capacitor having a sufficiently large capacitance C' compared to the capacitance C of the load capacitor, and a charger connected to both ends A and A' of the power supply capacitor to charge it to voltage V'. A load charging switch element S for opening and closing a connection between a DC power supply connected via an impedance, the power supply capacitor connected to one end A of the power supply capacitor, and a load, and the switch element S Output terminal B for supplying pulse voltage to the load connected to the other end, and output terminal B from terminal A.
An inductance for generating transient vibrations connected in series to the path leading to the power supply capacitor, another output terminal B' connected to the other end A' of the power supply capacitor, and an inductance connected in antiparallel to the switch element S between A and B. Another load capacitance charge recovery switch element S' connected thereto and another load capacitance residual charge discharge switch element S' connected between the output terminals B and B' for opening and closing the connection therebetween. '', and a load capacitor for preventing reverse charging connected between the output terminals B and B' in antiparallel to the switch element S'' and with a rectification direction that prevents the charging voltage of the power supply capacitor. It has a rectifying element G for switching the switch elements S, S', S'' from S→S'→
In the order of S''→S→S'→S''......, the pulse width is a minute time slightly larger than the half cycle of vibration of the power supply capacitor, inductance, and load capacitor circuit, and the pulse pause time T'. It has a control unit that sequentially closes the circuit at time intervals,
As a result, the switch elements S, S', and S'' are opened and closed, and a power supply capacitor, which is charged to voltage V' in advance by closing the switch element S, is connected to the load, thereby achieving extremely low attenuation. After generating a strong transient vibration and charging the load capacitor to a voltage V approximately twice V', S is opened, and then the switch element S' is closed after a period of the required pulse width τ, thereby recharging the power supply. A capacitive load charged to a higher voltage is connected to the capacitor, and most of the charge stored in the load capacitor is recovered to the power supply capacitor due to the extremely poorly damped transient vibration that occurs. Afterwards, S′ is opened, and immediately after that, the switch element S″ is closed to discharge the charge remaining in the load capacitor that cannot be recovered, and B→S″→B′→G→B
2. A pulse power source characterized in that S'' is opened after the residual voltage of the load capacitor is attenuated as a circulating current in a closed circuit and the residual voltage of the load capacitor is returned to 0. 2. , S′, S″ are pulsed power supplies characterized by using silicon-controlled rectifying elements. 3. A power supply capacitor having a sufficiently large capacitance C' compared to the capacitance C of the load capacitor, and a charging impedance connected to both ends A and A' of the capacitor to charge it to voltage V'. a rectifying element G ₁ ′ connected in a bridge shape for opening and closing the connection between the DC power supply located at the location, the power supply capacitor connected to one end A of the power supply capacitor, and the load;
A bridge rectifier circuit in which a switch element S is connected between diagonal points of G ₂ ′, G ₃ ′, and G ₄ ′, and an output terminal for supplying pulse voltage to a load connected to the other end of the bridge rectifier circuit. B, an inductance for generating transient vibrations connected in series in the path from the terminal A to B, another output terminal B' connected to the other end A' of the power supply capacitor, and the output terminal B, Another load capacitance residual charge discharge switch element connected between B' and for opening and closing the connection therebetween.
The switch element is connected between S'' and the output terminals B and B'.
a load capacitor reverse charge prevention rectifier G connected in antiparallel to S'' and in a rectifying direction that prevents the charging voltage of the power supply capacitor;
The switch elements S, S″ are changed from S→S″→S→S″...
A pulse power source characterized by having a control unit that closes a circuit in the order of... 4. A power supply capacitor having a sufficiently large capacitance C' compared to the capacitance C of the load capacitor, and a charging impedance connected to both ends A and A' of the capacitor to charge it to voltage V'. a load charging switch element S for opening and closing the connection between the DC power supply at the location, the power supply capacitor connected to one end A of the power supply capacitor, and the load; and a load charging switch element S connected to the other end of the switch element S. output terminal B for supplying pulse voltage to the load, and output terminal B from terminal A.
An inductance for generating transient vibrations connected in series to the path leading to the power supply capacitor, another output terminal B' connected to the other end A' of the power supply capacitor, and an inductance connected in antiparallel to the switch element S between A and B. connected rectifier
G″ and the inductance connected in parallel with it
l', and another load capacitance residual charge discharge switch element S'' connected between the output terminals B and B' for opening and closing the connection therebetween;
A rectifying element G for preventing reverse charging of the load capacitor is connected between B' in anti-parallel to the switch element S'' and in a rectifying direction that prevents the charging voltage of the power supply capacitor; The switch element S,
A pulse power source characterized by having a control unit that sequentially closes S'' in the order of S→S''→S→S''. A power supply capacitor having a capacitance C', a DC power supply connected to both ends A and A' via a charging impedance to charge it to a voltage V', and a DC power supply connected to one end A of the power supply capacitor. a load charging switch element S for opening and closing the connection between the power supply capacitor and the load; an output terminal B for supplying a pulse voltage to the load connected to the other end of the switch element S; terminal A to B
An inductance for generating transient vibrations connected in series to the path leading to the power supply capacitor, another output terminal B' connected to the other end A' of the power supply capacitor, and an inductance connected in antiparallel to the switch element S between A and B. Another load capacitance charge recovery switch element S' connected thereto and another load capacitance residual charge discharge switch element S' connected between the output terminals B and B' for opening and closing the connection therebetween. '', and a load capacitor for preventing reverse charging connected between the output terminals B and B' in antiparallel to the switch element S'' and with a rectification direction that prevents the charging voltage of the power supply capacitor. It has a rectifying element G for switching the switch elements S, S', S'' from S→S'→
In the order of S''→S→S'→S'', the pulse width is a minute time slightly larger than the half cycle of vibration of the power supply capacitor, inductance, and load capacitor circuit, followed by a pulse pause time T'. A pulse power source having a control unit that sequentially closes the circuit at a time interval of On the other hand, the secondary winding in a sufficiently boosted relationship is connected to both terminals A and A' of the power supply capacitor via a rectifier G, thereby reducing the energy remaining in the load capacitor after S' is opened. A pulse power supply characterized in that the power is recovered to the power supply capacitor by closing S''. 6. A power supply capacitor having a sufficiently large capacitance C' compared to the capacitance C of the load capacitor, and a charging impedance connected to both ends A and A' of the capacitor to charge it to voltage V'. a rectifying element G ₁ ′ connected in a bridge shape for opening and closing the connection between the DC power supply located at the location, the power supply capacitor connected to one end A of the power supply capacitor, and the load;
A bridge rectifier circuit in which a switch element S is connected between diagonal points of G ₂ ′, G ₃ ′, and G ₄ ′, and an output terminal for supplying pulse voltage to a load connected to the other end of the bridge rectifier circuit. B, an inductance for generating transient vibrations connected in series in the path from the terminal A to B, another output terminal B' connected to the other end A' of the power supply capacitor, and the output terminal B, Another load capacitance residual charge discharge switch element connected between B' and for opening and closing the connection therebetween.
The switch element is connected between S'' and the output terminals B and B'.
a load capacitor reverse charge prevention rectifier G connected in antiparallel to S'' and in a rectifying direction that prevents the charging voltage of the power supply capacitor;
The switch elements S, S″ are changed from S→S″→S→S″...
A pulse power supply having a control unit that closes the circuit in the order of... is equipped with a regenerative transformer, the primary winding of which is connected in series to the switch element S'' between the terminals B and B', and The secondary winding in the step-up relationship is connected to both terminals A and A' of the power supply capacitor via a rectifier G, thereby draining the energy remaining in the load capacitor after S' is opened.
A pulse power source characterized in that the power is recovered to the power supply capacitor by closing a circuit S''.7 A power supply capacitor having a capacitance C' sufficiently larger than the capacitance C of the load capacitor, and a To open and close the connection between the DC power supply connected to A' via a charging impedance in order to charge it to voltage V', and the power supply capacitor connected to one end A of the power supply capacitor and the load. a load charging switch element S, an output terminal B for supplying a pulse voltage to the load connected to the other end of the switch element S, and a
An inductance for generating transient vibrations connected in series to the path leading to the power supply capacitor, another output terminal B' connected to the other end A' of the power supply capacitor, and an inductance connected in antiparallel to the switch element S between A and B. connected rectifier
G″ and the inductance connected in series with it
l', and another load capacitance residual charge discharge switch element S'' connected between the output terminals B and B' for opening and closing the connection therebetween;
A rectifying element G for preventing reverse charging of the load capacitor is connected between B' in anti-parallel to the switch element S'' and in a rectifying direction that prevents the charging voltage of the power supply capacitor; The switch element S,
In a pulse power source having a control section that closes S'' in the order of S→S''→S→S'......
A regenerative transformer is provided, the primary winding of which is connected in series with the switch element S'' between the terminals B and B', and the secondary winding that is in a sufficiently boosted relation with the switch element S'' is connected to the rectifier G. Both terminals A of the power supply capacitor via
A pulse power supply characterized in that the energy remaining in the load capacitor after S' is opened is recovered to the power supply capacitor by closing S'.8 Compared to the capacitance C of the load capacitor. A power supply capacitor having a sufficiently large capacitance C', a DC power supply connected to both ends A and A' of the power supply capacitor via a charging impedance in order to charge it to voltage V', and A load charging switch element S for opening and closing the connection between the power supply capacitor connected to one end A and the load, and an output for supplying pulse voltage to the load connected to the other end of the switch element S. Terminal B and B from terminal A
An inductance for generating transient vibrations connected in series to the path leading to the power supply capacitor, another output terminal B' connected to the other end A' of the power supply capacitor, and an inductance connected in antiparallel to the switch element S between A and B. Another load capacitance charge recovery switch element S' connected thereto and another load capacitance residual charge discharge switch element S' connected between the output terminals B and B' for opening and closing the connection therebetween. '', and a load capacitor for preventing reverse charging connected between the output terminals B and B' in antiparallel to the switch element S'' and with a rectification direction that prevents the charging voltage of the power supply capacitor. It has a rectifying element G for switching the switch elements S, S', S'' from S→S'→
In the order of S''→S→S'→S''......, the pulse width is a minute time slightly larger than the half cycle of vibration of the power supply capacitor, inductance, and load capacitor circuit, and the pulse pause time T'. In a pulse power supply having a control unit that sequentially closes circuits at time intervals, its output terminals B and B' are connected in series to output terminals E and E' of a DC high voltage power supply, and
A pulse power source characterized in that terminals B and E' of the combined power source connected in series are connected between a discharge electrode and a dust collection electrode of an electrostatic precipitator comprising a discharge electrode and a dust collection electrode.