JPH0140453B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cylindrical circuit breaker with a resistive contact, and more particularly to a cylindrical circuit breaker with a resistive contact, which includes a main contact, a resistive contact, a resistor, and the like.

With the increase in electricity demand, the transmission voltage and capacity of the power system are increasing, and even in Japan, the transmission voltage and capacity are increasing.
The realization of a 1000kV class UHV system is progressing. Considering the rationalization of air insulation in UHV systems,
It is necessary to suppress surges generated in UHV systems to extremely low values. For this reason, it is unavoidable to introduce a resistor disconnection method in the shield disconnectors used in UHV systems, in addition to the resistor input required in conventional systems.

The basic configuration of this resistor breaker consists of a main contact, a resistive contact, and a resistor, and the circuit consists of a resistor 2 and a resistor contact in parallel with the main contact 1, as shown in Figure 1 or 2. 3 is connected in series (see Figure 1), and resistance contact 3 is connected in series to a parallel circuit of main contact 1 and resistor 2 (see Figure 2).
It is. In both of these circuits, the short circuit current is first diverted by the main contact 1 to the circuit of the resistor 2, and then the short circuit current, which is limited by the resistor 2, is transferred to the resistor contact 3. The severance is complete. On the other hand, in the closing operation, the resistor 2 is used also as a closing resistor, but the operation sequence differs depending on whether it is used as a dedicated resistor for closing or closing. That is, in the former case, the resistance contact 3 is closed, and the main contact 1 is closed after the advance closing time has elapsed. On the other hand, in the latter case, main contact 1 and resistance contact 3
and the resistance contact 3 is closed almost simultaneously or with a delay. The configuration shown in these drawings is what is called a break unit, and in a multi-point cutter or disconnector, multiple cutters or breakers are connected in series using these as a structural unit. configured.

By the way, the above-mentioned shearing operation will be explained in more detail with reference to FIG. 3, which shows time on the horizontal axis. When the on/off command signal (current) 4 is issued at time _t1 , the current 7 flows, and after the time required for generating sufficient operating force in the operating mechanism has elapsed, the movable side electrode of the main contact starts moving according to the operating characteristic of curve 5. Then, the main contact opens at time t ₂ and moves until it reaches the distance between the electrodes necessary for current interruption, and then transfers to the resistor at the zero point of the interruption current that occurs within time width T ₁ . complete the flow. On the other hand, the resistive contact uses some kind of delay means to delay the operation of the main contact along curve 6, and similarly opens at time _t3 , and at the current zero point that occurs within time width _T2 . Cuts off the current flowing through the resistor. The time t ₃ during which the resistance contact opens during such non-operation or disconnection operation is generally set after the end of the time width T ₁ in which the main contact completes commutation to the resistor.
Various types of delay operation mechanisms for the main contact of the resistance contact have been proposed. However, in all of the proposed delay operation mechanisms, the operation delay time of the resistance contact with respect to the main contact is determined mechanically to a constant value in relation to the operation of the main contact, so Regarding the amount of heat, there were drawbacks as described below.

The amount of heat generated in the resistor, Q, is expressed as Q=E ² /R×T (1), where E is the voltage applied to the resistor, R is the resistance value, and T is the application time. In a UHV system resistor sheath disconnection, the applied voltage E is large, the resistance value R is small, and the application time T is several times as large as the closing resistance, so the amount of heat generated is extremely large. This application time T indicates the time from the time of commutation by the main contact to the time of breakage of the resistance contact, and its maximum value is shown in Figure 3 when the main contact completes the commutation to the resistor. T ₃ is the period from the start of the time width T ₁ to the end of the time width T ₂ when the resistance contact stops the current flowing through the resistor. The resistor installed in this tester or disconnector is designed to resist the maximum value of the application time T
It must be designed to have sufficient heat capacity to withstand T ₃ , making it extremely large-scale.

The present invention has been made in view of the above points,
The purpose is to reduce the amount of heat generated by the resistor and to provide a cylindrical circuit breaker with a resistive contact whose volume is reduced.

In other words, the present invention provides an operating mechanism for opening and opening a resistive contact, a delay operating mechanism that generates a driving force through a delay means associated with the breaking operation of the main contact, and a delay operating mechanism that generates a driving force through a delay means associated with the breaking operation of the main contact, and a The present invention is characterized by comprising a current detection operation mechanism that detects current and generates a driving force.

The present invention will be explained below based on the illustrated embodiments. FIG. 4 shows an embodiment of the present invention. Note that parts that are the same as those in the conventional model are given the same reference numerals, and therefore their explanations will be omitted. In this embodiment, the operating mechanism for opening and opening the resistive contact 3 is composed of a delay operating mechanism 8a that generates a driving force via a delay means 8 associated with the breaking operation of the main contact 3, and a predetermined amount of force flowing through the resistor 2. The current detection operating mechanism 10a generates a driving force by detecting a current of more than 100 liters. A main contact operating device 9 that disconnects the main contact 1 from the delay operating mechanism 8a
The current detecting operation mechanism 10a is composed of a first resistive contact operating device 10 that generates a driving force via a delay means 8 associated with the operation of the current detecting section 11 and a second resistive contact operating device 10. Consisting of an operating device 12,
The current detection unit 11 is formed of a coil 16 (one-turn magnetic coil) consisting of a fixed piece 13, a movable piece 14, and a minute gap 15, which are interlinked with the current circuit flowing through the resistor 2. By doing this,
The resistance contact 3 is opened by the current detection operation mechanism 10a when the current flowing through the resistor 2 exceeds a predetermined value, which has a large effect on the amount of heat generated and shortens the energization time when the current is interrupted. As a result, the amount of heat generated by resistor 2 decreases, and resistor 2
It is possible to obtain a cylindrical disconnector with a resistive contact that reduces the amount of heat generated and has a reduced volume.

That is, as shown in the figure, the current flows from one terminal 17 through the main contact 1 to the other terminal 18.
In this state, when the shearing command current flows to the shearing coil 19, the main contact operating device 9 starts operating, and the movable side electrode 21 of the main contact 1 is moved through the insulating rod 20. Drive in the direction of the arrow shown inside to open the main contact 1. As a result, main contact 1
An arc is generated between the electrodes of the resistor 2, which is extinguished by an appropriate arc extinguishing means and commutated to the circuit of the resistor 2. There are various arc extinguishing methods using various arc extinguishing media, but for high voltage and large capacity applications, a puffer type arc extinguisher using _SF6 gas is often used. . Next, either the first resistive contact operating device 10 or the second resistive contact operating device 12 starts operating, and the movable electrode 23 of the resistive contact 3 is connected via the insulating rod 22, as shown in the figure. The resistive contact 3 is opened or opened by driving in the direction of the arrow. When the contact is opened, an arc is generated between the electrodes of the resistance contact 3 as in the case of the main contact 1, but this is extinguished by an appropriate arc extinguishing means. The shearing ability required of this resistance contact 3 is small compared to that of the main contact 1 because the shearing current is limited by the resistor 2 and is small. Typically, the same arc-extinguishing medium as the main contact 1 is used, and it is often composed of small-scale folds and sections.

By the way, when the resistance contact 3 is opened in this manner, the amount of heat generated in the resistor 2 can be reduced and the volume can be reduced, which will be explained next. The amount of heat Q generated in the resistor 2 is expressed as the current I _R flowing through the resistor 2.
Expression (1) above becomes Q=R・I _R ²・T (2). As is clear from equation (2), if the current of a predetermined magnitude or more detected by the current detection unit 11, that is, the detectable limit current, is set to, for example, 1/2 of the designed maximum current of the resistor 2, this In the event that the current is not detected by the current detection unit 11 at a value lower than the set value or the current is not detected, the allowable conduction time of the current I _R flowing through the resistor 2 is at least four times the design maximum current, and the conduction time is Even if it grows a little, it is not a big problem. On the other hand, when the current I _R flowing through the resistor 2 is larger than the above set value, the main contact 1 When the current is interrupted and current begins to flow through the resistor 2, the current detection unit 11 detects this current with a detection delay time (for example, 1 ms or less), and the second resistor contact operating device 12 immediately operates. Therefore, it is possible to shorten the current application time from when the current is commutated to the resistor 2 until the resistance contact 3 cuts it off, and the amount of heat generated can be reduced. In this respect, as shown in FIG. 3, the time width T ₁ during which the main contact 1 commutates to the resistor 2 is
The effect is greatest when the resistance contact 3 opens immediately after the commutation of the resistor 2, and the shortened time in this case can be simply evaluated to be approximately equal to the time width T ₁ in which the main contact 1 completes commutation to the resistor 2. This is close to 10ms, but this means that the conventional design maximum current conduction time T ₃ is 30ms, so the current conduction time can be shortened by approximately 1/3. Moreover, since this value is proportional to the required volume of the resistor 2, the size of the resistor 2 can be reduced to about 2/3 of the conventional size.

If we analyze this by taking into account the phase of the cut-off current, we get the following. In general, in cases where the amount of heat generated by the resistor 2 is a problem, the resistor 2
The power factor of the circuit is close to zero, and the value of the shear resistance is large compared to the impedance of the circuit, so when the shear current is commutated to resistor 2, it is in phase with the power supply voltage. The current is close to . In other words, the time from when the current is commutated to the resistor 2 to the current zero point is approximately every 0.25〓 to 0.5〓, but in this embodiment, the first current zero point, that is, the current conduction time of the resistor 2 is 0.25〓. Although it is difficult to break the current, it can be easily broken at the next current zero point of 0.75〓. For example, it is sufficient to set the current detection time to 0.1〓, the contact opening time to 0.15〓, and the minimum arc time of the resistance contact to 0.5〓. In this way, the current is detected immediately after the current is commutated to the resistor 2, and the resistance contact 3 starts operating, so that the current zero point is always reached at approximately the same arcing time, both synchronously and intermittently. The current appears, and the current can be cut off, and the energization time of resistor 2 is 0.75〓.
It is approximately 15ms, and the energization time T in the above equation (2) can be reduced to 1/2 of the conventional energization time of 30ms.
The energization time T can be further reduced compared to the case where the phase of the cut-off current is not taken into consideration.

As the delay means 8, an electric one (relay type) using a delay circuit or an auxiliary contact, an outflow fluid (fluid type), or a compression time constant of a compressible fluid (compression/filling time constant type) is used. Either a fluid type, a mechanical type that uses the idle operating time of a mechanical mechanism (idle operating time formula excluding the current detection mechanism), or an elastic time constant of an elastic body such as a spring (elastic time constant formula), etc. You may also use And the first and second
As the resistance contact operating devices 10 and 12, a pressurized fluid independent of the main contact operating device 9 may be used as a driving force source, or energy is stored by the operation of the main contact operating device 9. Although an elastic body such as a spring may be used, the driving force source of the first and second resistance contact operating devices 10 and 12 is shared, and only the mechanism for controlling the start of operation is made independent, and the output of the delay means 8 is also used. , current detection section 1
It is effective to configure the system so that it can be controlled even with one output. As a mechanism for controlling the start of this operation, for example, a valve is used when the driving force source is pressurized fluid, and a locking hook is used when the driving force source is a stored spring. Furthermore, as the current detection section 11, the above-mentioned coil 16 which can obtain a relatively large mechanical output is used.
(1-turn magnetic coil) In addition to those that insert a microresistance into the circuit of resistor 2, or use a part of resistor 2 to detect the voltage drop, and those that detect the electric field. , one that is magnetically driven, etc. are used.

Another embodiment of the invention is shown in FIG. In this embodiment, the delay operation mechanism 8b and the current detection operation mechanism 10b share an elastic body 24, for example, a spring 24a provided at a high potential portion, as their driving force source. In this way, most of the drive mechanism of the spring 24a and equal resistance contact 3 is shared, and the spring 24a, which stores energy by the operation of the main contact 1, is provided in the high potential part, making it possible to make the installation of a resistance contact and the disconnector compact. It can be configured as follows. In other words, the insulating rod 25 is driven in the direction of the arrow shown in the figure by an actuator (not shown) using a shearing command current, and the lever 2 is
6, the movable side electrode 21 of the main contact 1 is driven in the right direction in the figure, which is the cross-sectional direction, to open the main contact 1. At the same time, the lever 28 is rotated clockwise via the insulating rod 27 connected to the insulating rod 25, and the washer 30 of the spring 24a is moved as shown in the figure by the rod 29 connected to the lever 28. Press in the direction of the arrow to charge the spring 24a. At this time, the other washer 31 of the spring 24a is connected to the insulating rod 3.
2. Current detection unit 1 via lever 33 and cam 34
It is locked by a hook portion 35 provided on one movable piece 14 and does not move. At this time, the lever 33 and the cam 34 are each receiving a clockwise rotational force due to the angle of their contact surfaces, and the lever 28 has an engaging portion 36 for closing and an arm 37 as a delay means due to idle operation.
is provided. At the end of the operation of the operating device (not shown), the arm 37 of the delay means rotates clockwise and engages the lower end of the rod 38.
Push 8 upwards. This pushed up rod 3
The upper end of the movable piece 8 contacts the tip of the movable piece 14 of the current detection section 11, and pushes it up to disengage the hook part 35 provided on the movable piece 14. When the hook portion 35 is disengaged in this way, the stored spring 2
4a, the movable electrode 23 of the resistance contact 3 is driven to the right in the figure, which is the cutting direction.
Resistance contact 3 is opened. When the current flowing through the resistor 2 is equal to or greater than a predetermined magnitude in response to the opening of the resistor contact 3 by this delay means, the current detection unit 11 provided in the conductor 39 of the circuit of the resistor 2 detects this. The movable piece 14 is attracted, and the hook part 35 is disengaged without waiting for the disengagement of the hook part 35 due to the idle operation of the arm 37, which is the delay means, and the resistive contact is opened with the energy of the stored spring 24a. By driving the movable electrode 23 of No. 3 in the right direction in the figure in the cross-section direction,
Resistance contact 3 is opened. In this way, in the case of the present embodiment, most of the driving force source and driving mechanism for the resistance contacts 3 are shared, so that there is an effect that the circuit breaker can be made compact in structure.

As described above, the present invention uses a current detection operation mechanism that detects the current flowing through the resistor and generates a driving force to open the resistive contact when the current flowing through the resistor is greater than or equal to a predetermined magnitude. If the current is less than a predetermined value, the main contact is opened via a delay means associated with the opening/breaking operation of the main contact, so if the current is greater than a predetermined value, the current detection operation mechanism is used to open the main contact without going through the delay means. As a result, the amount of heat generated by the resistor is reduced by shortening the conduction time of the current that has a large effect on the amount of heat generated, and the amount of heat generated by the resistor is reduced.Resistance contacts with reduced volume You can get attachments and disconnections.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of the slit section of a cylindrical breaker with a resistive contact, Fig. 2 is a circuit diagram of another example of a cylindrical breaker with a resistive contact, and Fig. 3 is a circuit diagram of a conventional slit breaker. FIG. 4 is an explanatory diagram illustrating the shearing operation of an embodiment of the shunt breaker with a resistive contact according to the present invention; FIG. FIG. 5 is a longitudinal sectional side view of the main part of a sheath breaker of another embodiment of the sheath breaker with a resistance contact according to the present invention. DESCRIPTION OF SYMBOLS 1... Main contact, 2... Resistor, 3... Resistance contact, 8... Delay means, 8a, 8b... Delay operation mechanism, 9... Main contact operating device, 10... First resistance contact 10a, 10b...Current detection operating mechanism, 11...Current detection unit, 12...Second resistance contact operating device, 16...Coil (1 turn magnetic coil), 21...Main contact Movable side electrode, 23...
Movable electrode of resistance contact, 24...Elastic body, 24a
...Spring.

Claims (1)

[Scope of Claims] 1. In a device consisting of at least a main contact, a resistive contact, and a resistor, the operating mechanism for opening and closing the resistive contact is controlled by a driving force via a delay means associated with the opening and breaking operation of the main contact. a delay operation mechanism that generates
A sheath breaker with a resistive contact, comprising: a current detection operating mechanism that detects a current of a predetermined magnitude or more flowing through the resistor and generates a driving force. 2. Claim 1, wherein the current detection operation mechanism detects the current with a coil installed interlinked with the current circuit flowing through the resistor.
Disconnector with resistance contact as described in section. 3. A sheath breaker with a resistance contact according to claim 1, wherein the delay operation mechanism and the current detection operation mechanism share an elastic body provided in a high potential portion as a driving force source.