JPS63140513A - Capacitor device - 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 (Field of Industrial Application) The present invention relates to a capacitor device, and more particularly to a capacitor device that improves discharge performance when energization is stopped and reduces power loss when energizes.

(Prior art) Phase advance capacitor devices are installed in AC power transmission and distribution lines, etc. to improve the power factor, but one of the performances required of such capacitor devices is There is a discharge performance when the residual charge is discharged after stopping. In order to cause this discharge to occur quickly, in conventional capacitor devices,
As shown in FIG. 6, a resistor element 6 is connected to a capacitor element 61.
2 are connected in parallel, and the residual charge accumulated in the capacitor element 61 is discharged through the resistor element 62.

(Problem to be solved by the invention) By the way, when energizing the capacitor device as described above,
Naturally, a current also flows through the discharging resistive element 62, and the power consumed by this current becomes power transmission/distribution loss. Therefore, if an attempt is made to improve the above-mentioned discharge performance by interposing a resistive element with a small resistance value, the current flowing through this resistive element during energization will increase,
Therefore, when electricity is applied, a large power loss occurs. As described above, in the past, it has not been possible to improve discharge performance and reduce power loss at the same time.

This invention has been made to solve the above conventional problems, and its purpose is to provide a capacitor device that has low power loss when energized and has excellent discharge performance when energized. .

(Means for Solving the Problems) Therefore, in the capacitor device of the present invention, a resistor element is connected in parallel to a capacitor element, an external terminal is connected to the capacitor element, and the capacitor device is opened when the external terminal is energized. On the other hand, an open/close switch that closes when the current is not energized is connected in series with the resistive element.

(Function) In the capacitor device with the above configuration, the current flowing through the resistor element becomes zero due to the on-off switch that opens when energized, and on the other hand, when the current is not energized, the on-off switch closes, so after energization stops, the capacitor closes as before. A resistive element is connected in parallel to the element, and the residual charge in the capacitor element is discharged through this resistive element.

(Effects of the Invention) As described above, by connecting the open/close switch in series with the resistive element, which opens when energized and closes when de-energized, regardless of the resistance value of the resistive element,
The power loss in this resistive element during energization is zero. Therefore, the loss in this capacitor device can be significantly reduced, and on the other hand, since the power loss during energization does not depend on the resistance value of the resistor element, the resistance value of the resistor element can be set as an appropriate value for speeding up the discharge. It is possible to select L, thereby improving the discharge performance.

(Embodiments) Next, specific embodiments of the capacitor device of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic circuit diagram showing the internal configuration of a capacitor device in a first embodiment of the present invention, and as shown in the figure,
A capacitor element 12 is arranged inside the case 11 and connected to external terminals U and (2) respectively attached to the end face of the case 11. And this capacitor element 1
An electromagnet 13 is interposed in the connection line L connecting the external terminal 2 and one of the external terminals V. Furthermore, a resistor element 14 and an on/off switch 15 connected in series to the resistor element 14 are connected in parallel to the capacitor element 12 . Movable piece 16 that opens and closes the contacts of the above-mentioned open/close switch 15
is so constructed that when the electromagnet 13 is turned on, it is attracted by it and opens the contact, and when the electromagnet 13 is turned off, the contact is closed by a return spring (not shown).

In the above configuration, when an alternating current voltage is applied to the external terminals U and (2), current flows to the electromagnet 13 as well as the capacitor element 12, and therefore, when the electromagnet 13 is turned on, the above-mentioned open/close switch 15 is opened. . Therefore, the current flowing through the resistive element 14 is zero, and when the capacitor device is energized, the resistive element 14
The power loss at is zero. On the other hand, when the electricity supply to the capacitor device is stopped, the electromagnet 13 is turned off. Therefore, the open/close switch 15 is closed, and the resistor element 14 is connected in parallel to the capacitor element 12, so that the residual charge in the capacitor element 12 is quickly discharged through the resistor element 14. The discharge time is determined by the capacitance of the capacitor element 12 and the resistance element 14.
However, in conventional devices, if a resistor element with a small resistance value is selected, the discharge time will be shortened, but this will conversely result in an increase in power loss during energization. However, in the above device, the resistance value of the resistor element 14 is unrelated to the magnitude of power loss during energization, so it is possible to select an element with a resistance value that can provide appropriate discharge performance. It is possible to reduce power loss during energization and to improve discharge performance when energization is stopped.

Next, with reference to FIGS. 2 to 5, the second to fifth
The capacitor devices in the embodiments will be described. The difference in each of these embodiments from the device in the first embodiment lies in the operating configuration of the on/off switches 25 to 55, and the other configurations are the same, so the following description will be made. In the description of the second to fifth embodiments, functional parts that are the same as those of the first embodiment are given the same numbers and their explanations are omitted. In addition, the second ~
In the fifth embodiment, the external terminal V and the capacitor element 12
The two are directly connected by a line L without interposing an electromagnet 13 or the like between them.

In the second embodiment of the invention shown in FIG. 2, the open/close switch 25 connected in series to the resistive element 14 is constituted by a heat-sensitive switch. During the operation of supplying current to the capacitor device, this is due to dielectric loss in the capacitor element 12 and the like. The temperature of the entire capacitor device increases due to heat generation, and the opening/closing switch 25 is a normally closed switch that opens in response to the increased temperature. Therefore, when an AC voltage is applied to the capacitor device, current also flows through the resistor element 14 at the initial stage, but this gradually increases due to the heat generated at that time and the heat generated by the dielectric loss in the capacitor element 12 described above. When the temperature of the capacitor device increases and the temperature exceeds the switching temperature of the on-off switch 25, the on-off switch 25 is in the open operation state. The loss at 14 becomes zero. On the other hand, when energization is stopped, the open/close switch 25 closes again as the temperature of the capacitor device decreases, so that the residual charge in the capacitor element 12 is discharged through the resistor element 14.

As described above, although the device of the second embodiment causes a slight delay in the switching operation of the open/close switch 25 compared to the device of the first embodiment, it has a simpler structure and can be energized similarly to the first embodiment. It is possible to reduce the loss during operation and improve the discharge performance when the current is stopped.

In the capacitor device according to the third embodiment of the present invention shown in FIG. 3, an open/close switch 35 having a movable contact piece 36 similar to that of the first embodiment is connected. The movable contact piece 36 is connected to the wall surface of the case 11.
It is made to be linked to the expansion displacement at the time of thermal expansion of No. 1. That is, when the current is not energized, the open/close switch 35 is in a closed state, and when the temperature of the capacitor device rises and the case 11 thermally expands as described above when energized, the movable contact piece 36 is separated from the contact point and the open/close switch 35 is closed. 35 is designed to open. Therefore, substantially similar to the device of the second embodiment, the connection state of the resistive element 14 to the capacitor element 12 is automatically switched depending on the temperature difference of the entire capacitor device between the energized state and the de-energized state of the capacitor device. Therefore, it is possible to reduce loss during energization and improve discharge performance when energization is stopped.

Next, a fourth embodiment of the present invention shown in FIG. 4 will be described.
is composed of a semiconductor switching element having three terminals: switching terminals T1 and T2 connected to the resistance element 14 and line L, respectively, and a gate terminal G for controlling the conduction state between these switching terminals T1 and T12. has been done. The other end of the control line LG connected to the gate terminal G is wound around the line L, and the end thereof is grounded. Therefore, when a voltage is applied to the capacitor device and an alternating current flows through the line L, an induced electromotive force is generated in the control line LG, thereby controlling the conduction state between the switching terminals TI and 12. That is, when the capacitor device is energized, the induced electromotive force is generated, which cuts off the opening/closing terminals T1 and 12, and no current flows through the resistor element 14. On the other hand, when the energization is stopped, no current flows through the control line LG. Since no voltage is generated, the open/close terminals T1 and T12 are electrically connected at this time, and the residual charge in the capacitor element 12 is discharged through the resistor element 14. In the capacitor device having the above structure, since the structure is an open/close switch with no moving parts, the life and reliability are improved.

Next, a fifth embodiment shown in FIG. 5 will be described. In the capacitor device of this embodiment, like the device of the second embodiment described above, an open/close switch 55 made of a heat-sensitive switch is connected in series to the resistive element 14. This heat-sensitive switch has a movable piece made of bimetal or shape memory alloy, is normally in a closed position, and opens at a predetermined temperature or higher. In the above device, a parallel connection circuit of a heating resistance element 56 and a compensation capacitor element 57 is interposed in the connection line L between the capacitor element 12 and the external terminal V. The other connection terminal of the open/close switch 55 connected to the resistance element 14 is connected to the connection point between the parallel circuit and the capacitor element 12. The heating resistance element 56 is for heating the opening/closing switch 55 made of the heat-sensitive switch,
It is arranged at a position along the opening/closing switch 55.

The heating resistive element 56 may be composed of a resistor having a fixed resistance value, or may be composed of a positive temperature coefficient thermistor such as a ceramistor.

The resistance value of the heating resistance element 56 and the capacitance value of the compensation capacitor element 57 are respectively the resistance value of the resistance element 1.
4 and capacitor element 12 are selected.

When the capacitor device having the above configuration starts to be energized, current flows not only to the main current flowing through the capacitor element 12 but also to the open/close switch 55 and the resistor element 14 which are in the closed operation state.
At this time, current also flows through the heating resistance element 56, which generates heat, and the temperature of the on-off switch 55 rises and opens, and the current flowing through the resistance element 14 is cut off. Ru. In the second embodiment described above, the temperature of the entire capacitor device rises due to heat generation due to dielectric loss of the capacitor element 12, and the opening/closing switch 25 is opened in response to the temperature. In the device, a heating resistance element 56 for heating the open/close switch 55 is dedicated to heat only the open/close switch 25, which has a small heat capacity, so that rapid heating and
Rapid cooling is possible, and the current flowing through the resistive element 14 is interrupted within a short time after the start of energization, making it possible to further reduce power loss. Furthermore, the switching temperature of the open/close switch 55 can be set to a higher temperature than that of the device in the second embodiment, thereby making it possible to prevent malfunctions. In the above device, current continues to flow through the heating resistance element 56 even after the opening/closing switch 55 is opened, and therefore heating of the opening/closing switch 55 is continued. The cut-off state of element 14 is maintained. In addition, when the heating resistance element 56 is made of a ceramic, it should be constructed so that the temperature is balanced by the amount of heat generated by the resistance value at a suitable temperature higher than the switching temperature at which the open/close switch 55 is opened. This makes it possible to prevent overheating and reduce loss in the heating resistance element 56. Note that the voltage applied across the heating resistive element 56, whose resistance value changes in this way, is kept approximately constant by the compensating capacitor 57 connected in parallel thereto.

When the power supply is stopped in the above device, the heating resistance element 56 no longer generates heat, and therefore the temperature of the opening/closing switch 55 rapidly decreases, and when the temperature falls below the switching temperature, the closing operation is performed. Resistance element 14 is connected in parallel to capacitor element 12, and capacitor element 1
The residual charge at 2 is discharged through the resistive element 14.

As described above, in the capacitor device of the present invention, the resistor element 14 connected in parallel to the capacitor element 12 is further provided with an on/off switch that opens when the device is energized and closes when the device is de-energized. Since they are connected in series, it is possible to reduce power loss during energization and improve discharge characteristics when energization is stopped. It should be noted that the above-mentioned embodiments in which various operating modes of the above-mentioned opening/closing switch are explained by way of examples do not limit this invention, and various modifications can be made within the scope of this invention, and each of the above-mentioned embodiments Although the present invention has been described with reference to a phase advance capacitor device for power factor improvement, the present invention can also be applied to other grounding capacitor devices and surge absorbing capacitor devices.

[Brief explanation of the drawing]

1 to 5 show the first to fifth parts of the capacitor device of the present invention.
FIG. 6 is a schematic diagram of the internal circuit of the device showing the fifth embodiment, and FIG. 6 is a schematic diagram of the internal circuit of the conventional device. 12... Capacitor element, 14... Resistance element, 15
．． 25.35.45.55... Open/close switch, U, ■
...External terminal. Patent applicant: Shizuki Denki Seisakusho Co., Ltd. Agent: Masahiro Nishimori, /i ll,: Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. A resistive element is connected in parallel to the capacitor element, an external terminal is connected to the capacitor element, and an open/close switch is connected to the resistive element, which opens when the external terminal is energized and closes when the external terminal is not energized. A capacitor device characterized by being connected in series with.