JPH11145793A - Pulsating power source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulsating power source which is capable of surely processing kickback energy, while relatively simplifying the constitution of a pulse generation circuit as well as the control of a semiconductor switch. SOLUTION: An initial stage capacitor C0 is initially charged from a charger 2 through a semiconductor switch SW0 , then a pulse current is supplied from the capacitor to a magnetic pulse compression circuit by a semiconductor switch SW and is supplied to a load, whereas a kickback current returning from the load to the capacitor is made to flow to a resistor R through a diode D, so that the kickback energy is consumed as heat loss. Also, a reactor is provided in series with the diode and the resistor and the constitution of generating the vibration current of a half cycle with the capacitor, when the capacitor is charged to an opposite polarity by the kickback current and of consuming the kickback energy in the resistor is provided as well.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse power supply that generates a large current pulse having a narrow width by combining a pulse generation circuit using a power semiconductor switch and a magnetic pulse compression circuit, and particularly supplies a pulse current to a load. And a kickback energy processing circuit.

[0002]

2. Description of the Related Art FIG. 5 shows a configuration example of a pulse power supply. The pulse generation circuit 1 initially charges the power first-stage capacitor C ₀ by the charger 2, and controls the semiconductor switch SW to turn on from the capacitor C ₀ to increase the voltage / magnetic pulse compression circuit 3.
Of the input stage pulse transformer PT.

[0003] booster-magnetic pulse compression circuit 3, the capacitor C ₁ and the high pressure charged with pulse current I ₀ that is pressurized by the pulse transformer PT, saturable reactors SI ₁ at the charging voltage of the capacitor C ₁ is operated magnetic switch Pulse current I ₁ from capacitor C ₁ to capacitor C ₂
High pressure charge the capacitor C ₂ by generating further pulses narrow and high voltage to a load 4 such as an excimer laser from the capacitor C ₂ by the saturable reactor SI ₂ at the charging voltage of the capacitor C ₂ is operated magnetic switch Supply current.

In the pulse power supply having such a configuration, the load 4 does not consume all the supplied pulse power,
Some energy returns to the pulsed power supply. This returning energy (called kickback energy)
If left as it is, a residual charge is generated in a capacitor in the circuit, thereby reducing the pulse current accuracy or deteriorating the magnetic characteristics of the saturable reactor.

[0005] Therefore, keep regenerates kickback energy to the first stage capacitor C _0, the regenerative type to be used for the next charge cycle as part of the charging energy has been put into practical use. In this regenerative pulse power supply, since the direction of the kickback current is opposite to the charging direction required to generate the first pulse from the first-stage capacitor, a circuit for inverting the kickback voltage is added.

FIG. 6 shows a conventional first-stage pulse generating circuit having a regenerative function. An IGBT is used for the semiconductor switch SW in FIGS. 7A to 7C, and the saturable reactor SI ₀ is provided for magnetic assist for reducing the turn-on loss of the switch when discharging the capacitor C ₀ . The diode D ₁ is reverse voltage protection of the semiconductor switch SW.

In FIG. 1A, after the capacitor C ₀ is discharged by turning on the semiconductor switch SW, the semiconductor switch SW is supplied with a kickback current from the pulse transformer PT.
, The capacitor C ₀ is charged to the opposite polarity. This charge generates an oscillating current from the capacitor C ₀ through the diode D ₀ in the reactor L _0, to obtain a regeneration of kickback energy by inverting charge the capacitor C ₀ to the polarity during initial charge.

In FIG. 1B, a diode D ₂ is added to the circuit of FIG. 2A to prevent the voltage of the capacitor C ₀ charged in the opposite polarity from leaking to the pulse transformer PT.

In FIG. 1C, an oscillating current is generated from the capacitor C ₀ charged to the opposite polarity by the kickback current via the diode D ₁ and the saturable reactor L ₁ .

Various circuits have been proposed for magnetic pulse compression, such as using a saturable transformer instead of an input-stage pulse transformer as the magnetic pulse compression circuit 3.

[0011]

In THE INVENTION Problems to be Solved conventional pulse power supply, kickback energy from the booster-magnetic pulse compression circuit 3 in order to change the state of the load, the kickback voltage is returned to the capacitor C ₀ of the first stage This causes a change in time, complicates the timing control of the semiconductor switch SW, and complicates the control circuit.

The voltage of the capacitor C ₀ and the semiconductor switch S
FIG. 7 shows the relationship between the currents flowing through W. In the figure, when the ON control of the semiconductor switch SW at time t _1, the discharge of the capacitor C ₀ saturable reactor SI voltage time of the magnetic product and the time T ₁ determined by the magnitude of the voltage of the capacitor C ₀ of ₀ Started with a delay. Time T ₃ to the inversion charge in the positive polarity period of time T ₂ and the capacitor C ₀ to the charging of the opposite polarity of the capacitor C ₀ by kickback current from the discharge of the capacitor C ₀ is the magnitude of the kickback amount Change.

With respect to such a change in time T _{1 to} T ₃ ,
The semiconductor switch SW performs the period T ₄ during which the kickback voltage is inverted for reliable regeneration of kickback energy.
It is necessary to perform turn-off control in anticipation of timing.

[0014] The turn-off control method, in the circuit of FIG. 6 (a), there is a feedback control system for detecting a current polarity and current direction of the capacitor C _0, to extra voltage and current sensors are required, A malfunction may damage the semiconductor switch.

[0015] In this regard, in the circuit of FIG. (B), can be a semiconductor switch protection by intervention of the diode D _2, still sensor is required.

In addition, in the circuit shown in FIG. 1C, in addition to the need for a sensor, a kickback reversal current flows through the pulse transformer PT following the kickback current. As a result, the outflow of energy occurs on the secondary side of the PT, and the energy regeneration efficiency is deteriorated.

It is an object of the present invention to provide a pulse power supply which can make the configuration of a pulse generating circuit relatively simple and control a semiconductor switch relatively easily while reliably processing kickback energy.

[0018]

According to the present invention, in order to solve the above-mentioned problems, kickback energy from a load side is consumed as heat loss by a resistor without regenerating, and vibration between a capacitor and a reactor is generated. A current is generated and consumed as heat loss by a resistor, and is characterized by the following configuration.

In a pulse power supply for initially charging a first-stage capacitor, compressing a pulse current generated by discharging the capacitor into magnetic pulses, and supplying the load to a load, a second power supply that is turned on when an initial charging current is supplied from the charger to the capacitor. A first semiconductor switch, a second semiconductor switch that is turned on when a discharge current is supplied from the capacitor to the load side, and a series circuit of a resistor and a diode connected in parallel to the capacitor. Is directed to prevent the initial charging current of the capacitor through the first semiconductor switch from flowing to the resistor, and the resistor is a kickback energy returning from the load side to the capacitor side through the second semiconductor switch. Is consumed as heat loss.

In addition, a reactor is provided in the series circuit of the diode and the resistor, and the reactor has a half-period oscillation between the capacitor and the capacitor when the capacitor is charged to the opposite polarity by the kickback current from the load side. It is characterized in that kickback energy is consumed as heat loss by the resistor by generating a current.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 is a pulse generation circuit diagram showing an embodiment of the present invention, and includes circuit elements of FIG. 6 including other embodiments described below. Equivalent parts are indicated by the same reference numerals.

The configuration of FIG. 1 is different from that of FIG. 6B in that a resistor R is provided in series with the diode D ₀ except for the reactor L ₀ , and the initial charging current path from the charger 2 to the capacitor C ₀ is provided. there is a point in which a semiconductor switch SW _0. In addition,
Diode D ₃ connected in parallel with opposite polarity direction to the semiconductor switch SW ₀ is for protection against reverse voltage of the switch SW _0.

In this embodiment, the semiconductor switch SW
₀ is ON-controlled only during charging from the charger 2 to the capacitor C ₀ , and during and after discharging of the capacitor C ₀
Prevents discharges the capacitor C ₀ side from.

After the capacitor C ₀ is initially charged by the on control of the switch SW ₀ , the capacitor C ₀ is discharged by the on control of the switch SW ₀ and the saturable reactor SI ₀ and the pulse transformer P 2.
Carried by the current path through the primary winding and the diode D ₂ of the T.

The kickback current from the pulse transformer PT is supplied to the switch SW which is maintained in the ON control state.
Flows through the current path through the diode D ₂ and the capacitor C ₀
To the opposite polarity. At this time, the capacitor C
₀ series circuit of the diode D ₀ in parallel resistor R is interposed, kickback current without charging the capacitor C ₀ to the opposite polarity, it is consumed as the heat loss by the resistor R through the diode D _0.

FIG. 2 shows the waveform of each part at this time. By the ON control of the semiconductor switch SW ₀ , the capacitor C ₀
After being charged to _C0, at time t ₁ the semiconductor switch SW is controlled to the on state discharged from the capacitor C ₀ to the pulse transformer PT side with a delay of time T ₁ in the magnetic assist by saturable reactor SI ₀ is made.

When the kickback current from the load 4 appears in the switch SW through the pulse transformer PT (time t ₂ ), the constants of the capacitor C ₀ and the resistance R including the stray inductance are critical or close to the constant. If set to a constant, most of the kickback current flows as a current i _R through the diode D ₀ and the resistor R, and energy is instantaneously consumed as heat loss. On the other hand, the capacitor C
₀ has a small current i _{C0 due to} the forward voltage component of the diode D _0.
Only occurs.

Although a small residual voltage is generated in the capacitor C ₀ , the residual voltage can be consumed by the resistor R due to stray inductance or the like.

After the kickback current has been consumed by the resistor R (time t ₃ ), the semiconductor switch S waits for an appropriate time.
W is turned off to prepare for the next pulse generation.

[0030] Therefore, according to this embodiment, the kickback energy without charging the capacitor C ₀ to the opposite polarity, is consumed instantaneously by the resistance R. Moreover, it is not affected at all by the change in kickback energy depending on the load condition. Further, since the kickback energy is completely consumed by the resistor, the capacitor C _{0 is} generated by the kickback current.
Is not charged, and does not leak to the load side even when the semiconductor switch SW is kept on.

From this, the turn-off control of the semiconductor switch SW can be performed at an appropriate time, the control is simplified, and the semiconductor switch SW is not turned off at an erroneous timing, thereby preventing the semiconductor switch SW from being damaged. . Furthermore, the kickback current is controlled by the pulse transformer PT.
The pulse does not flow out to the side, and an unstable operation is not caused in the next pulse generation. Further, the voltage and current sensors required in the conventional circuit become unnecessary.

[0032] In addition, the capacitor C ₀ by the switch SW ₀
Since the conventional reactor L ₀ does not intervene in the charging of
A high charging accuracy can be obtained while simplifying the charging circuit.

(Second Embodiment) FIG. 3 shows another embodiment of the present invention. 1 differs from FIG. 1 in that a reactor L is inserted in a series circuit of a diode D ₀ and a resistor R.

The reactor L temporarily stores the kickback current in the capacitor C ₀ and generates a half-period oscillating current with the capacitor C ₀ so that the kickback energy is consumed as heat loss by the resistor R. belongs to. The constant of the reactor L is set to a critical value or a value close thereto so that the capacitor C ₀ is not recharged when the kickback current flows through the resistor R.

FIG. 4 shows the waveform of each part. When the kickback current starts flowing at time t ₂ , the kickback current flows through the capacitor C ₀ and is stored as charging energy by the presence of the reactor L, and the kickback current is stored. At the end of the current (time t ₃ ), a half-period oscillating current is generated between the capacitor C ₀ and the reactor L, and the kickback energy is consumed by the resistor R by the oscillating current.

The semiconductor switch SW is controlled to be turned off at an appropriate time after the time t _{4 at} which the oscillation current cycle ends.

[0037] Thus, according to this embodiment, in addition to the effects of the first embodiment, suppresses the kickback energy is consumed instantaneously by the resistance R, thereby the maximum flowing through the diode D ₀ current And reduce the current duty. Further, since the resistor R consumes kickback energy for a relatively long time as compared with the case of FIG. 1, a resistor having a small rated power can be used.

In each of the embodiments described above, the case where the switches SW and SW ₀ are IGBTs is shown. However, the same effects can be obtained by replacing the switches with power FETs, GTOs, thyratrons and the like. In the case of the switch with reverse conduction blocking capability, it can be omitted diode D ₂ and D ₃ in FIG. 1 and FIG.

[0039]

As described above, according to the present invention, kickback energy from the load side is consumed as heat loss by a resistor without regenerating, and furthermore, an oscillating current is generated between the capacitor and the reactor. The following effects are obtained because the heat is consumed as heat loss by the resistor.

(1) Since the regeneration of kickback energy is not performed, the circuit configuration and its control are simplified, and the kickback energy can be reliably processed.

(2) Since the kickback energy is completely consumed by the resistor, the residual voltage of the capacitor does not leak to the load side.

[0042] (3) that the reactor L ₀ for regeneration does not intervene to the charging current path, and the residual voltage is not generated in the capacitor, it is possible to enhance the charging accuracy while simplifying the charging control.

(4) When a reactor for generating an oscillating current between the capacitor and the capacitor is provided, the duty of the resistor and the diode in series with the resistor can be reduced.

[Brief description of the drawings]

FIG. 1 is a pulse generation circuit diagram showing an embodiment of the present invention.

FIG. 2 is an operation waveform in the embodiment.

FIG. 3 is a pulse generation circuit diagram showing another embodiment of the present invention.

FIG. 4 is an operation waveform according to another embodiment.

FIG. 5 is a circuit example of a pulse power supply.

FIG. 6 is a diagram of a conventional pulse generation circuit.

FIG. 7 shows a pulse generation / regeneration operation waveform of a conventional circuit.

[Explanation of symbols]

1 ... pulse generating circuit 2 ... Charger 3 ... boost-magnetic pulse compression circuit 4 ... load SW, SW ₀ ... semiconductor switch SI ₀ ~SI ₂ ... saturable reactor L, L _0, L ₃ ... reactor C ₀ ... capacitor D ₁ to D ₃ ... diodes PT ... pulse transformer R ... resistance

Claims (2)

[Claims] 1. A pulse power source for initially charging a first-stage capacitor, compressing a pulse current generated by discharging the capacitor into a magnetic pulse, and supplying the load to a load. A first semiconductor switch, a second semiconductor switch that is turned on when a discharge current is supplied from the capacitor to a load side, and a series circuit of a resistor and a diode connected in parallel to the capacitor. The diode is oriented to prevent the initial charging current of the capacitor through the first semiconductor switch from flowing to the resistor, and the resistor is kicked from the load side back to the capacitor side through the second semiconductor switch. A pulse power supply characterized in that back energy is consumed as heat loss. 2. A reactor is provided in a series circuit of the diode and the resistor, and the reactor has a half-period oscillation between the capacitor and the capacitor when the capacitor is charged to a reverse polarity by a kickback current from the load side. The pulse power supply according to claim 1, wherein a kickback energy is consumed as heat loss by the resistor by generating a current.