JPH02168865A - Pulse modulator and capacitor charging device - Google Patents

Abstract

PURPOSE:To feed power stored in a power collecting capacitor to another load, by connecting the power collecting capacitor to the secondary winding of a charging choke transformer via a switch means, in a pulse modulator. CONSTITUTION:When a switch element 11 is ignited, then energy stored in a PFN(pulse forming circuit)10 is fed to a load device 12 in the shape of pulse. When the voltage of the PFN 10 reaches a specified value, then the output of ON-command signal is generated from a comparator 17, and a thyristor 13 is ignited. Then, current left on the primary side of a charge choke transformer 8 is transferred to a secondary side. Then, the reverse current of current from the side of the PFN 10 is suppressed by a hold-off diode 9 connected in series, and the voltage of the PFN 10 is kept to come to a value set by a setting device 18.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pulse modulation device, and relates to a high-power device used, for example, as a power source for a klystron for a particle accelerator or a power source for a nuclear fusion device.

[Conventional technology]

A pulse modulation device generally generates high-voltage pulsed power using a pulse shaping circuit made up of capacitors connected in a ladder shape via a reactor, and supplies it to a load device such as a klystron via a switching element such as a thyratron. It has become.

Conventionally, as a pulse modulation device with such a configuration, literature (
Stanford University Two Mile Accelerator: The
5TANFORD TWO-MILEACCELERA
TOR-R, B, NeaQ, 1
968. W, Nee, Benjamin Inc.:
W., A. B., Benjamin Inc.) is known.

According to what is described in the above literature, a voltage doubler resonance charging method using a charging choke transformer is used to charge a ladder-type pulse forming circuit (hereinafter referred to as PFN) of a capacitor and a reactor, and when a predetermined voltage is reached. The method used was to dissipate excess energy using a resistor.

[Problem to be solved by the invention]

Although the above-mentioned conventional technology works effectively in controlling the charging voltage of the PFN to a predetermined voltage, it has a configuration in which excess energy is consumed by the resistor, and as the capacity of the device increases, the generation of There are problems in that not only the cooling device for cooling the loss becomes large, but also the efficiency of the device is poor and the operating cost becomes enormous.

Furthermore, due to the above reasons, there is a limit to the control range of the PFN charging voltage in the conventional technology, and to cover this, it is necessary to accurately control the DC power supply voltage using an induction voltage regulator, etc. There was also the problem of mechanical life.

Further, the above-mentioned problem exists not only in pulse modulation devices but also in devices equipped with a capacitor charging circuit that charges a load capacitor to nearly double the DC power supply voltage via a charging choke transformer.

SUMMARY OF THE INVENTION An object of the present invention is to provide a capacitor charging circuit and a pulse modulation device equipped with the capacitor charging circuit, which can control the charging voltage of a capacitor such as a pulse shaping circuit without consuming power for adjustment through a resistor. Our goal is to provide the following.

[Means to solve the problem]

In order to achieve the above object, the present invention connects a charging choke transformer having a secondary winding to the output end of a DC power supply and a pulse shaping circuit through a series circuit of diodes, and the pulse shaping circuit includes a plurality of pulse shaping circuits. In a pulse modulation device that is formed by connecting capacitors in a ladder shape via a reactor and supplies pulsed power to a load via a switch element, a power recovery capacitor is connected to the secondary winding of the charging choke transformer via a switch means. is connected, detects the terminal voltage on the power supply side of the pulse shaping circuit, turns on the switch means when the detected voltage is equal to or higher than a set value, and supplies the power accumulated in the power recovery capacitor to another load. It is characterized by having a configuration in which:

[Effect]

The output of the DC power supply is connected to the PFN via a charging choke transformer.
is supplied to the power side end of the When the switch element connected to the output end of the PFN is fired, the energy stored in the PFN is outputted to the load device in the form of a pulse. After this PF
The N capacitor and the charging chimique transformer form a resonant circuit, and the voltage of PFN is charged to nearly twice the DC power supply voltage.

When the voltage of PFN reaches a predetermined set value or more, a switch means connected to the secondary side of the charging choke transformer is turned on. As a result, the current flowing through the primary winding of the charging choke transformer is commutated to the secondary winding. At this time, PF
The reverse flow of current from the N side is blocked by the series-connected diode, and the voltage of PFN is kept constant. on the other hand,
At this point, the energy remaining in the charging choke transformer is stored in the power recovery capacitor on the secondary side. The power stored in this capacitor is supplied to other loads and discharged. This discharge is performed until the next pulse output generated by PFN. Namely.

Surplus power exceeding the charging voltage required for PFN pulse generation is stored in a power recovery capacitor via a charging choke transformer, and the same amount of power as this stored charge is supplied to other loads. Become. Therefore, there is no loss like when surplus power is consumed by a resistor.
The average value of the charging voltage of the PFN capacitor can be controlled to a predetermined value. This results in improved equipment efficiency and
This means that an economical, highly reliable, and large-capacity pulse modulator can be achieved through miniaturization.

Note that as the other load mentioned above, an inverter that converts the power stored in the power recovery capacitor into AC power, a secondary battery that is directly charged in place of the capacitor, etc. can be applied. When an inverter is used, its output can drive auxiliary equipment such as a cooling fan of the pulse modulation device.

〔Example〕

Hereinafter, the present invention will be explained based on examples.

FIG. 1 shows a block diagram of a pulse modulation device according to an embodiment of the present invention. In the figure, a DC power supply 1 converts AC power supplied from an AC power supply 2 into DC power, and includes an induction voltage regulator 3 for controlling voltage, a rectifier transformer 4, a diode rectifier 5, a DC reactor 6, It is composed of a capacitor 7 and the like. The output of this DC power supply 1 is supplied to a pulse shaping circuit (PFN) 10 via a charging choke transformer 8 having a secondary winding and a hold-off diode 9. This PFNIO is formed into a ladder shape by connecting a plurality of n capacitors via reactors, and a load device 12 is connected to the output end of the final stage via a switch element 11.

On the other hand, a power recovery capacitor 14 is connected to the secondary winding of the charging choke transformer 8 via a thyristor 13 as a switching means. The voltage across the capacitor 14 is supplied to an inverter 15, and the output of the inverter 15 is regenerated to the AC power supply 2.

Further, a voltage detector 16 is connected to the power supply side end of PFNIO, and the voltage detected by this is compared with a set value inputted from a setting device 18 in a comparator 17, and when the detected voltage is equal to or higher than the set value, the thyristor 13, an on command is output.

The operation of the embodiment configured as described above will be described next.

Since the characteristic impedance of the PFNIO and the impedance of the load device 12 are designed to match, when the switching element 11 is fired, the energy stored in the PFNIO is supplied to the load device 12 in a pulsed manner. This P
When charging the FNIO, since the capacitor and the charging choke transformer 2 form a resonant circuit, the voltage of the PFNIO is charged from 0 to nearly twice the output voltage E of the DC power supply 1. 1) When the voltage of F N 10 reaches a predetermined value (for example, 1.9E), an on command signal is output from the comparator 17, and the thyristor 13 is fired.

As a result, the current remaining on the primary side of the charging choke transformer 8 is commutated to the secondary side. Then, the reverse flow of current from the PFNIO side is blocked by the serially connected hold-off diode 9, and the voltage of PFN is maintained at the value set by the setting device 18. Due to this operation, the energy remaining in the charging choke 1-lance 8 is stored in the power recovery capacitor 14 connected to the secondary side. The inverter 15 connected to this capacitor 14 is connected to the switch element 1
1 ignites the pine and repeats the above-mentioned operation, the same amount of charge as previously charged in the capacitor 14 is regenerated to the two AC power supply systems. This inverter 12 may be of a known configuration, and for example, as shown in FIG. The balance of the circuit is maintained by controlling the current to maintain a constant current. Note that the regeneration by the inverter 15 is controlled so as to maintain the average voltage across the power recovery capacitor 14 at a constant value.

As described above, according to this embodiment, the power recovery capacitor 14 and the inverter 15 can be connected to each other without consuming the surplus energy related to the voltage control of PFNIO by the setting device 18 in the resistor.
Since the pulse modulator is recirculated to the AC power source 2 via , the control range of the PFN charging voltage can be expanded.

This eliminates the need for frequent control of the DC power supply voltage by an induction voltage regulator that covers the limits of the conventional control range, and also solves the problem of mechanical life of the induction voltage regulator.

The above embodiment relates to a high power pulse modulation device using PFN, but as shown in FIG. The present invention can also be applied to a capacitor charging device that charges the capacitor from 1 to 2 times the output voltage of the DC power supply 1. In this case as well, the efficiency of the device is improved as described above.

It is possible to realize a compact, economical and highly reliable capacitor charging device.

Furthermore, in a system in which a plurality of devices are used in parallel as shown in FIG. 4, the power recovery capacitor 14 and the inverter 15 connected to the secondary side of the charging choke transformer 8 can be used in common. This allows the device to be further downsized.

FIG. 5 shows an example in which a secondary battery 26 is used as a means for storing energy remaining in the charging choke transformer. According to this, it is not necessary to perform regeneration using an inverter. Further, the charged secondary battery 26 is replaced with another one by a switching means when the apparatus is stopped or during operation.

According to this, it is possible to further simplify and downsize the device.

FIG. 6 shows an example in which the output of the inverter 15 is used as an auxiliary power source. For example, if the cooling fan 27 of the pulse modulation device is connected as a load and the rotation speed of the fan is controlled by the inverter 15 according to the amount of charge charged in the capacitor 14 connected to the secondary side of the charging choke transformer 8, it is possible to When the equipment can be effectively cooled and the amount of loss generated by the equipment is small, the loss of the auxiliary equipment is also reduced, further improving the efficiency of the equipment.

〔Effect of the invention〕

As explained above, according to the present invention, surplus power exceeding the charging voltage required for PFN pulse generation etc. is stored in the power recovery capacitor via the charging choke transformer.
The same amount of power as this stored charge amount = 14 = will be supplied to other loads.

Therefore, the average value of the charging voltage of the PFN capacitor can be controlled to a predetermined value without causing a loss as would occur if surplus power is consumed by a resistor. As a result, the efficiency of the device can be improved, the device can be made smaller, and an economical, reliable, and large-capacity pulse modulator can be realized.

Furthermore, when applied to a capacitor charging device, the same effects as described above can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a pulse modulation device according to an embodiment of the present invention;
Fig. 2 is an example diagram of an inverter according to the first embodiment, Fig. 3 is a configuration diagram of a capacitor charging device according to an embodiment of the present invention, and Fig. 4 is an illustration of a system in which a plurality of pulse modulation devices are installed in parallel. FIGS. 5 and 6 are block diagrams of a pulse modulation device according to other embodiments, respectively. 1. DC power supply, 8. Charging choke 1-lance, 9. Halt diode, 10. Pulse shaping circuit, 12. Load device, 13. Thyristor, 14. Capacitor for power recovery, 15. - Inverter, 16... Voltage detector, 17... Comparator, 18... Setting device, 25... Load capacitor, 26... Secondary battery, 27... Cooling fan.

Claims (1)

[Claims] 1. A pulse shaping circuit is connected to the output end of a DC power source via a series circuit of a charging choke transformer having a secondary winding and a diode, and the pulse shaping circuit connects a plurality of capacitors to a reactor. In the pulse modulation device, which is connected in a ladder shape through a switching element and supplies pulsed power to a load through a switching element, a power recovery capacitor is connected to a secondary winding of the charging choke transformer via a switching means. , detecting the terminal voltage on the power supply side of the pulse shaping circuit and turning on the switch means when the average value of the detected voltage is equal to or higher than a set value, and supplying the power accumulated in the power recovery capacitor to another load; A pulse modulation device characterized by having a configuration in which: 2. The pulse modulation device according to claim 1, wherein the other load is an inverter that converts the power stored in the power recovery capacitor into alternating current power. 3. The pulse modulation device according to claim 2, wherein the pulse modulation device is configured to regenerate the output of the inverter to an AC power system. 4. The pulse modulation device according to claim 2, wherein the output of the inverter is used as a power source for an auxiliary device of the pulse modulation device. 5. The pulse modulation device according to claim 3, wherein the inverter performs constant current control on the output current so as to maintain a constant average value of the terminal voltage of the power recovery capacitor. 6. The auxiliary device is a cooling fan of the pulse modulation device, and the inverter is configured to control the rotation speed of the cooling fan according to the amount of electric power stored in the power recovery capacitor. The pulse modulation device according to claim 4. 7. A device comprising a plurality of pulse modulation devices according to any one of claims 3, 4, 5, and 6, characterized in that the power recovery capacitor and the inverter are provided in common. 8. A pulse shaping circuit is connected to the output end of the DC power supply through a series circuit of a charging choke transformer having a secondary winding and a diode, and the pulse shaping circuit connects multiple capacitors in a ladder shape through a reactor. In the pulse modulation device which is connected to each other and supplies pulsed power to a load via a switch element, a secondary battery is connected to the secondary winding of the charging choke transformer via a switch means, and the power source of the pulse shaping circuit is connected to the secondary winding of the charging choke transformer. detecting the side terminal voltage and turning on the switch means when the average value of the detected voltage is equal to or higher than a set value;
A pulse modulation device characterized in that the secondary battery is charged by the power stored in the power recovery capacitor. 9. The pulse modulation according to claim 8, wherein the secondary battery is connected to the secondary winding via means for detecting the completion of charging of the secondary battery and switching to another secondary battery. Device. 10. In a capacitor charging device comprising a charging choke transformer having a secondary winding at the output end of a DC power supply and a load capacitor connected through a series circuit of a diode, a switch means is provided in the secondary winding of the charging choke transformer. A power recovery capacitor is connected through the power recovery capacitor, the terminal voltage of the load capacitor is detected, and when the detected voltage is equal to or higher than a set value, the switch means is turned on, and the power accumulated in the power recovery capacitor is transferred to another load. 1. A capacitor charging device characterized by having a configuration in which a capacitor is charged.