JPS61154435A - Dc power soruce unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention particularly relates to an improvement of a DC type m-device using a superconducting coil as a load.

[Technical background of the invention and its problems] In a direct power supply device that uses a superconducting coil as a load, a phenomenon occurs in which the superconducting coil that is the load suddenly loses its superconductivity (hereinafter referred to as the quench phenomenon). There is. If this quench phenomenon occurs and all of the energy stored in the superconducting coil is consumed within the superconducting coil, various problems such as burnout of the coil conductor will occur. To prevent the energy being received from being dissipated within the superconducting coil! 'It is necessary to provide equipment.

FIG. 4 shows an example of the configuration of a conventional DC power supply device equipped with this type of protection device. In the figure, 1 is a superconducting coil as a load, 2 is a thyristor rectifier as a converter consisting of a semiconductor rectifying element that rectifies the output of an AC power source (not shown) and supplies DC current to the superconducting coil 1, and 3 is the superconducting coil 1 and A resistor 4 is connected in parallel to the DC output side of the thyristor rectifier 2 to absorb the energy stored in the superconducting coil 1 when a quench phenomenon occurs. It is a DC breaker. The DC breaker 4 is composed of a DC breaker 5 and a series circuit of a capacitor 6 and a switch 7 connected in parallel with the DC breaker 5, as shown in the figure. As the DC breaker 5, a vacuum breaker, a thyristor breaker, or the like is used, for example.

In the DC power supply device having such a configuration, in a normal operating state, a DC current is supplied to the superconducting coil 1 by the thyristor rectifier 2 as shown in FIG.

In this state, if a quench phenomenon occurs in the superconducting coil 1, the DC current is cut off by the DC switch or the disconnector 4, and the DC current flowing through the thyristor converter 2 and the superconducting coil 1 is reduced as shown in Fig. 6. By flowing the energy through the resistor 3 and the superconducting coil 1 as shown, the energy stored in the superconducting coil 1 is rapidly consumed by the resistor 3, thereby protecting the superconducting coil 1. At this time, in the DC breaker 4, by charging the capacitor 6 in advance and turning on the switch 7, a current in the direction opposite to the direction in which the current normally flows is superimposed on the DC breaker 5, and the DC By forcibly creating a current zero point in the cutoff section 5, the direct current is cut off.

Of course, in such DC power supply devices, the rated current is increasing with the progress of superconducting coil technology, so a large capacity one is required for the DC breaker 4, and as a result, Not only does this require a large device, but it also poses an economical problem.

[Object of the Invention] The present invention was made to solve the above-mentioned problems, and its purpose is to reliably protect superconducting coils from the quench phenomenon while downsizing the device and improving economic efficiency. The purpose of this invention is to provide a DC power supply device that is capable of

[Summary of the Invention] In order to achieve the above object, the present invention includes a converter including a semiconductor rectifying element that supplies direct current obtained by rectifying the output of an AC power source to a superconducting coil as a load, and the superconducting coil and Along with bypass pair operation of the converter consisting of the energy absorption resistor connected in parallel, the commutation capacitor charged to a predetermined polarity, and the semiconductor rectifier when a quench phenomenon occurs in the superconducting coil. It is characterized by comprising switches that close the circuit connected in series, and a commutation circuit connected in parallel to the converter made of the semiconductor rectifier on the DC output side of the converter made of the semiconductor rectifier. shall be.

[Embodiments of the invention] An embodiment of the present invention shown in the drawings will be described below.

FIG. 1 shows an example of the circuit configuration of a DC power supply device according to the present invention. The same parts as in FIGS. I will only describe it. That is, FIG. 1 omits the DC breaker 4 in FIG. 4, and instead includes a commutation capacitor 8 charged to a predetermined illustrated polarity, and a capacitor 8 for commutation when a quench phenomenon occurs in the superconducting coil 1. A commutation circuit consisting of a switch 9 connected in series that closes when the thyristor rectifier 2 operates as a bypass pair is connected to the DC output side of the thyristor rectifier 2 in parallel with the thyristor rectifier 2. be.

Next, the operation of the DC power supply device configured as described above will be explained using FIGS. 2(a) to 2(d).

In Fig. 2, numeral 2 indicates a thyristor rectifier, which is the same as that in Figs. 4 to 6 and Fig. 1, but in Figs. Details are shown using a rectifier as an example. Also, Figure 2 (a
) to (d), 10 is a three-phase AC power source connected to the AC input side of the thyristor rectifier 2 and serving as its power source.

In such a DC power supply device, in a normal operating state, the u-phase and ■-phase thyristors are energized to supply DC current to the superconducting coil 1, which is a load, as shown in FIG. 2(a), for example. On the other hand, the commutation capacitor 8 is charged to the predetermined polarity shown, and the switch 9 is open. Assume that a quench phenomenon has now occurred in the superconducting coil 1 in this state. At this time, the present DC power supply performs a protective operation, which is performed as follows.

That is, first, the V-phase thyristor is fired in the thyristor rectifier 2 to form a bypass pair in which DC current flows through the y-phase and the V-phase. This situation is shown in FIG. 2(b). Here, the bypass pair is × phase - U phase, 2 phase - W
It may be formed in any phase and may be determined at the timing of performing the protection operation. Then switch 9
By closing the capacitor 8 and discharging the charge stored in the capacitor 8 through the bypass pair y-v phase of the thyristor rectifier 2, the current zero point is forced to the thyristor of the y-phase to ■phase forming the bypass pair. make it. This situation is shown in FIG. 2(C). As a result, the y-phase and V-phase thyristors forming the bypass pair are turned off.
As shown in FIG. 2(d), the current flowing through the thyristor rectifier 2 is cut off and begins to flow through the resistor 3, and the energy stored in the superconducting coil 1 is consumed by the resistor 3. It turns out.

In the DC power supply device described above, the thyristor converter 2
Since the thyristors used in the above have sufficient current capacity and voltage margin to withstand normal operation, there is no problem at all even if such a protective operation is performed. Therefore,
In particular, it is possible to cut off the DC current by using the arm of the thyristor rectifier 2 as a breaker without providing a DC cutoff section with a large current capacity as in the conventional case. As a result, the superconducting coil 1 can be reliably protected without increasing the size of the device or reducing economic efficiency.

In the above explanation, the case where there is one set of superconducting coils 1 and one set of thyristor rectifiers 2 has been described, but the case is not limited to this. For example, as shown in FIG. The present invention can be similarly applied even in a case where the devices are connected.

Further, although a thyristor rectifier is used as a converter, the present invention is not limited to this, and a semiconductor rectifier such as a gate turn-off thyristor (GTO) may be used.

[Effects of the Invention] As explained above, according to the present invention, there is provided a converter including a semiconductor rectifying element that supplies direct current obtained by rectifying the output of an AC power source to a superconducting coil serving as a load, and the superconducting coil and an energy absorbing resistor connected in parallel,
A commutation capacitor charged to a predetermined polarity and a switch that closes when a converter consisting of the semiconductor rectifier is operated as a bypass pair when a quench phenomenon occurs in the superconducting coil are connected in series, and the semiconductor rectifier is connected in series. Since the DC output side of the converter consisting of a rectifying element is configured with a commutation circuit connected in parallel with the converter consisting of a semiconductor rectifying element, there is no need to provide a special DC cutoff part, and the device can be made compact. Thus, it is possible to provide a highly reliable DC power supply device that can reliably protect superconducting coils from quench phenomena while improving economic efficiency and efficiency.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing a DC power supply device according to an embodiment of the present invention, and FIGS. 2(a), (b), and (c). (d) is a diagram for explaining the effect of the same embodiment;
FIG. 4 is a configuration diagram showing another embodiment of the present invention, FIG. 4 is a configuration diagram showing a conventional DC power supply device, and FIGS. 5 and 6 are diagrams for explaining the operation of the conventional DC power supply device. be. 1... Superconducting coil, 2... Thyristor rectifier, 3
...Resistor, 4...DC breaker, 5...DC breaker, 6.8...Capacitor, 7.9...Switch, 10...3-phase AC power supply. Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 2 (a) (b) Figure 2 (C) (d) Figure 3 Figure 5 Figure 6

Claims (3)

[Claims] (1) a converter made of a semiconductor rectifying element that supplies direct current obtained by rectifying the output of an AC power source to a superconducting coil serving as a load; and an energy absorption resistor connected in parallel with the superconducting coil; A commutation capacitor charged to a predetermined polarity and a switch that closes when a converter consisting of the semiconductor rectifier is operated as a bypass pair when a quench phenomenon occurs in the superconducting coil are connected in series, and the semiconductor rectifier is connected in series. 1. A DC power supply device comprising a commutation circuit connected in parallel to a converter including a semiconductor rectifier on the DC output side of the converter including a rectifier. (2) Claim No. (2) characterized in that a converter made of a semiconductor rectifying element is used as the converter.
The DC power supply device described in item 1). (3) A patent claim characterized in that a plurality of superconducting coils and a plurality of converters are connected in series, and a commutation circuit as described above is connected to at least one of the converters. DC power supply device according to scope (1).