JPH08107042A - Capacitor device - Google Patents

Abstract

PURPOSE: To suppress a parasitic vibration by a method wherein a plurality of capacitor element columns which are respectively composed of a plurality of capacitor elements which are connected in series to each other with resistance elements therebetween are provided and connected in parallel to each other and are housed in an insulating cylinder. CONSTITUTION: A capacitor device 10 is connected in parallel to the arc extinguish chamber 28 of a breaker. A number of capacitor elements 1 are respectively composed of capacitor elements 1a and resistance elements 1b which are connected to the capacitor elements 1a in series. A capacitor element column 2 is composed of the capacitor elements 1 which are connected in series to each other. A plurality of the capacitor element columns 2 which are connected in parallel to each other are housed in an insulating cylinder 3. Fixed electrodes 5 and 6 are attached to both the top and bottom ends of the insulating cylinder 3 with bolts 4 and the capacitor element columns 2 are mechanically supported and fixed by the fixed electrodes 5 and 6 and, further, are electrically connected to the fixed electrodes 5 and 6. Moreover, springs 7 arc provided between the fixed electrode 5 and the ends of the axial direction of the capacitor element columns 2 individually so as to correspond to the respective columns 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacitor device,
In particular, the present invention relates to a capacitor device formed by stacking a plurality of capacitor elements in multiple stages.

[0002]

2. Description of the Related Art With the increase in capacity of electric power systems and the improvement of electricity quality, circuit breakers used in substations and switching stations are required to have high reliability as well as increase in breaking capacity due to high voltage and large current. There is.

On the other hand, when a line failure or the like occurs in the actual power system to interrupt the current by the breaker, the surge voltage generated between the main contacts of the breaker after the break because the power system is huge and complicated. That is, the transient recovery voltage usually has a very complicated waveform. For this reason, the circuit breaker is required to carry out a breaking duty under various conditions so that a sufficient breaking performance can be maintained even under various failure conditions.

In order to increase the breaking capacity of the circuit breaker and to improve reliability, it is important to increase the breaking capacity per breaker and reduce the number of parts.

Conventionally, in order to achieve such a breaking duty, a puffer type gas circuit breaker for cooling the arc and extinguishing the generated charged particles by blowing a compressed gas to the arc generated between the contacts. Is widely adopted. In the puffer type gas circuit breaker, a semi-enclosed gas space called an arc extinguishing chamber is provided, and a main contact is constructed in this space. Especially recently, the number of breaking points has been reduced by improving the performance of the puffer type gas circuit breaker.
Even with a 00kV circuit breaker, a single arc-extinguishing chamber has been developed and has already been put to practical use.

In the circuit breaker, the insulation of the main contacts must withstand the transient recovery voltage (TRV) that appears after the circuit breaks near the current zero point in order for the circuit break to succeed. Therefore, in order to improve the interruption performance, of course, the performance of the arc-extinguishing chamber itself is improved, but in addition to this, a capacitor is inserted in parallel with the contact inside the arc-extinguishing chamber, and the transient recovery voltage rise that appears after interruption. Improving the breaking performance by relaxing the time is also actually performed.

In a multi-point circuit breaker in which a plurality of arc extinguishing chambers are connected in series, adding a capacitor in parallel with the arc extinguishing chambers improves the voltage sharing of each arc extinguishing chamber. By adopting it, the breaking performance is improved.

By the way, a capacitor used for this purpose is one in which a metal foil or the like is used to form a capacitor inside an insulating cylinder made of epoxy resin, or inside the insulating cylinder as shown in Japanese Patent Application No. 5-129827. There exists, for example, one in which a large number of ceramic capacitors are connected in series. In particular,
A capacitor device in which a large number of ceramic capacitor elements are connected in series and parallel has a large degree of freedom in design with respect to withstand voltage performance and electrostatic capacity, and its application is further considered in the future.

FIG. 3 is a block diagram showing an example of a capacitor device in which a large number of such ceramic capacitors are connected in series. In FIG. 3, the capacitor elements 1 are connected in multiple stages in series according to withstand voltage performance to form a capacitor element array 2. In addition, the capacitor element array 2 for accommodating the required capacitance is housed in parallel inside the insulating cylinder 3. In addition, fixed electrodes 5 and 6 are attached to both ends of the insulating cylinder 3 with bolts 4, and a single capacitor device 10 is provided.
Are formed. The capacitor device 10 thus configured is connected in parallel with the arc extinguishing chamber 20 of the circuit breaker.

[0010]

By the way, in recent years, the high voltage of the electric power system has been further advanced, and the 1000 kV (VHV) power transmission plan is being advanced. For such a high voltage, it is necessary for the circuit breaker to improve the withstand voltage performance not only in the arc-extinguishing chamber that constitutes the circuit breaker but also in the above-mentioned capacitor that is provided with the arc-extinguishing chamber. Further, reduction of the number of breaking points requires improvement of withstand voltage performance per breaking portion. In order to improve the withstand voltage performance, the desired withstand voltage performance is actually obtained by increasing the number of stages of the capacitor element array.
However, as the number of series stages increases, it becomes more strongly affected by the increase in inductance due to multi-stage stacking and the stray capacitance of the capacitor element itself to the ground, which has the drawback that parasitic vibration easily occurs between capacitor element rows. are doing.

Now, this phenomenon will be briefly described. FIG. 2 shows an approximate equivalent circuit for one series element series from the viewpoint of facilitating analysis, as compared with FIG. 3 which is an example of a conventional capacitor device.

In FIG. 2, the resistance, inductance and capacitance of the capacitor element 1 are R, L and C. Further, the capacitance due to the direct column connection of the capacitor elements and the electrostatic capacitance with respect to the ground are Cs and Cg. In this case, since the capacitors are stacked in multiple stages, if handled as a distributed constant circuit, the response of each part of the capacitor when a quadrature wave is added as an input waveform is expressed by the following Laplace transform formula. (1) When the end part is a release condition

[0013]

[Equation 1] (2) When the terminal part is in a short circuit condition

[0014]

[Equation 2] Here, N is the number of serially connected capacitors, and i is the i-th position of the capacitor as viewed from the voltage application side. Also, γ
Is expressed by the following equation.

[0015]

(Equation 3) In both cases, the condition that the voltage waveform does not vibrate is C >> Cs
, Cg,

[0016]

It is known that R ² ≧ 4π ² L / (Cg + π ² Cs) (4). In an actual capacitor element, since the resistance value of the capacitor element itself is smaller than the condition of the expression (4), parasitic vibration is likely to occur due to a high frequency surge particularly at the time of interruption, and an excessive voltage is applied to a specific capacitor element. May be applied. As a result, the reliability of the capacitor device may be deteriorated, such that the element itself is broken or a local discharge is caused between the insulating container and the capacitor element.

The present invention has been proposed in order to solve the above drawbacks, and its purpose is to suppress the parasitic vibration to improve the withstand voltage performance and provide a highly reliable capacitor device. That is.

[0018]

SUMMARY OF THE INVENTION According to the present invention, a plurality of capacitor element columns, which are formed by stacking a plurality of capacitor elements in series connection through a resistance element, are arranged in parallel and connected in parallel in an insulating cylinder. It is characterized by being stored and configured.

[0019]

According to the capacitor device having the above structure, by connecting the capacitors in multiple stages in series,
Parasitic vibration that occurs incidentally can be suppressed by the resistance element connected in series, and thus the insulation reliability of the capacitor device can be prevented from decreasing.

When an elastic member is provided at the end of the capacitor element array, this elastic member presses the capacitor element array in the series direction to mechanically and reliably fix the capacitor elements. In addition, since the electrical connection can be ensured, the mechanical and electrical reliability can be improved.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 schematically shows the configuration of a capacitor device according to the present invention. In FIG. 1, the condenser device 10
Is connected in parallel with the arc-extinguishing chamber 20 of the circuit breaker. Here, the large number of capacitor elements 1 is composed of a capacitor element 1a and a resistor element 1b connected in series with the capacitor element 1a. The value of the resistance element 1b is selected so as to satisfy the condition of the expression (4). The resistance value varies depending on the capacitance of the capacitor element used and the circuit configuration, but the approximate value is 10 ohms or more. Then, a capacitor element array 2 formed by connecting the capacitor elements 1 in series in one row is connected in parallel and is housed inside the insulating cylinder 3.

Fixed electrodes 5 and 6 are attached by bolts 4 to the upper and lower ends of the insulating cylinder 3 in the figure, and the capacitor element row 2 housed inside the insulating cylinder is mechanically fixed by the fixed electrodes 5 and 6. Is supported and fixed to and electrically connected to.

An individual spring 7 corresponding to the capacitor element row 2 is provided between the fixed electrode 5 and the axial end portion of the capacitor element row 2 in the upper part of the figure. With this spring 7, each capacitor element array 2 can be reliably pressed in the series connection direction regardless of the dimensional difference between the capacitor element arrays 2. As a result, the capacitor elements 1 connected in series
It can be fixed mechanically and reliably and electrically connected between them. Therefore, it is possible to prevent the occurrence of chattering in the capacitor element array 2 due to vibration or the like generated during the operation of the circuit breaker.
Since no electrical connection failure occurs between them, the mechanical and electrical reliability of the capacitor device 10 can be improved.

Further, electrostatic shield electrodes 8 and 9 for the purpose of relaxing an electric field are attached to both ends of the insulating cylinder 3. As a result, the withstand voltage performance of the entire capacitor device 10 can be improved.

FIG. 2 is an electrical equivalent circuit of the capacitor device 10. This circuit is the same as the conventional embodiment, but the resistance R can be made equivalent by adding the resistance component of the present invention to the resistance of the capacitor element. here,
When the capacitance of the capacitor element is C and the value of the resistance element connected in series with it is R, the element values are selected so that the time constants RC of the respective element rows are approximately equal. As a result, the voltage sharing among the elements becomes uniform, and the withstand voltage of the entire capacitor device 10 can be improved.

According to this embodiment, in addition to the effects of the above embodiment, parasitic vibration of the capacitor element array 2 can be prevented in advance. That is, even in the case of stacking in multiple stages, an overvoltage is not applied to a specific element, so that the withstand voltage performance of the entire capacitor device 10 can be improved. In addition, reliability can be improved.

As described above, according to the present invention, in order to obtain the capacitors required to achieve the breaking performance, the capacitor elements are stacked against each other against the parasitic vibration that is additionally generated by stacking the capacitor elements in multiple stages. By inserting a resistor connected in series with this, it is possible to prevent the occurrence of parasitic vibration in advance.

Although the above description relates to the capacitor device according to the present invention, a columnar capacitor element is often used as the capacitor element. In this case, by making the shape of the resistance element approximately the same as the shape of the capacitor element, it is possible to prevent the misalignment between the capacitor element and the resistor. Further, as a derivative effect in this case, standardization of the dimensions of the entire capacitor device 10 can be achieved. For example,
When the outer diameters of the columnar shapes are the same, the insulating cylinder 3 has the same gap, so that an extra part for mechanical support is unnecessary. This helps further improve reliability.

Further, the capacitor element 1a and the resistor element 1
In order to improve the workability of assembly, it is considered that b is stacked in the insulating tube in multiple stages and then inserted into the insulating tube 3. In this case, gas replacement can be easily performed by providing a slit in the insulating tube in the length direction.

Further, by making the shape of the resistance element approximately the same as that of the capacitor element, it is possible to make the dimensions of the parts common, improve the reliability, and to provide a high withstand voltage and large capacity capacitor device. Can be formed. As a result, it is possible to eliminate the shortage of the mounting space for the capacitor, which is caused by the miniaturization of the circuit breaker with the capacitor.

[0031]

As described above, according to the present invention, in order to obtain a capacitor necessary to achieve the breaking performance, by stacking capacitor elements in multiple stages, parasitic vibrations that are incidentally generated By inserting a resistor connected in series with the capacitor element, the occurrence of parasitic vibration can be suppressed in advance. Thereby, the insulation reliability of the capacitor device can be improved.

[Brief description of drawings]

FIG. 1 is a solution diagram of a configuration example of a capacitor device according to an embodiment of the present invention.

FIG. 2 is an electrical equivalent circuit diagram according to an embodiment of the present invention.

FIG. 3 is an exemplary solution diagram of a conventional configuration.

[Explanation of symbols]

 1 ... Capacitor element 7 ... Spring 2 ... Capacitor element array 8, 9 ... Electrostatic shield electrode 3 ... Insulation cylinder 10 ... Capacitor device 4 ... Bolt 20 ... Arc extinguishing chamber 5, 6 ... Fixed electrode

Claims (5)

[Claims] 1. A plurality of capacitor element columns, which are formed by laminating a plurality of capacitor elements in series connection through a resistance element, are arranged in parallel and connected in parallel, and are housed in an insulating cylinder. Capacitor device to be. 2. The capacitor device according to claim 1, wherein an elastic member is disposed on at least one axial end of each of the plurality of capacitor element columns to press and fix the plurality of capacitor element columns. 3. The capacitor device according to claim 1, wherein the integrated value RC of the total capacitance value C of the capacitor elements of each capacitor element column and the total resistance value R of the resistor elements are substantially equal. 4. The capacitor device according to claim 1, wherein the shape of each capacitor element and each resistance element is substantially the same. 5. A circuit breaker having a configuration in which the capacitor device according to any one of claims 1 to 4 is connected in parallel with an arc extinguishing chamber.