JP2569638Y2 - GIS internal abnormal overheat monitoring device - Google Patents

Description

Description of invention] (a) relates this invention relates to internal overheating monitoring device GIS using SF ₆ gas (gas insulated switchgear).

(B) Conventional technology In general, GIS is one of the substation equipment that includes circuit breakers, disconnectors,
Devices such as current transformers and instrument transformers are stored in metal containers,
The storage space is filled with SF ₆ gas, realizing ultra-miniaturization, high reliability and safety. However, even in such a GIS, the probability of an internal accident occurring is not zero. Possibilities of accidents include, for example, loose connection of conductors inside the container or poor contact due to incomplete insertion of disconnector contacts, leading to final ground fault, short circuit, or phase loss through heating and melting. Conceivable. Usually, abnormal overheating occurs due to contact resistance of the contact portion due to poor contact, and the temperature of SF ₆ gas sealed in the GIS container rises. The rise in the gas temperature also raises the temperature of the tank wall above the GIS container.

As a conventional device that detects such abnormal heating from outside the GIS during operation, a temperature sensor installed on the tank upper wall detects a rise in the temperature of the tank upper wall, and this temperature exceeds a predetermined threshold. In this case, it was determined that abnormal overheating occurred inside the GIS.

(C) Problems to be solved by the present invention However, in the above-described device, the detection of abnormal overheating is performed in the temperature path of heating the conductor in the gas compartment → increasing the temperature of SF ₆ gas → increasing the temperature of the upper part of the tank wall. There is a problem that the detection sensitivity is not so good because the detection is performed based on the detection. That is, because of the presence of SF ₆ gas in the above temperature path, the temperature of the upper part of the tank wall does not rise sufficiently even if the conductor part is overheated, or it takes time until the temperature of the upper part of the tank wall rises. There was a problem.

The purpose of this inventor is to
An object of the present invention is to provide a device that monitors abnormal overheating inside a GIS by detecting whether the pressure of SF ₆ gas increases and detecting whether the gas pressure has increased to a predetermined value or more.

(D) Means for Solving the Problem FIG. 1 shows a configuration diagram of a GIS abnormal overheat monitoring device according to the present invention.

Here, the GIS container 1 is divided into five gas compartments A to E, and contains elements such as a gas circuit breaker, a disconnector, a grounding device, and a transformer for an instrument. The gas compartments are divided into gas compartments A, B, C, D through which a load current flows, and gas compartments E through which a load current does not flow (for example, an instrument transformer storage gas compartment). Each gas compartment AE is spatially separated by an insulating spacer 2. A gas charging / discharging unit 4 is connected to each of the gas compartments A to E via a valve 3. Gas pressure sensors S1 to S5 for detecting gas pressures in the gas sections A to E are connected to each gas charging / discharging section 4.

Further, the temperature sensor S _T is attached to the wall surface of the container 1.

The signals from the gas pressure sensors S1 to S5 are input to the insulation amplifier 5 via a communication cable, where they are amplified to an appropriate level and output to the low-pass filter LPF. The low-pass filter LPF removes high-frequency components of the signal. The multiplexer MPX sequentially takes in the output of the low-pass filter LPF and stores it in the memory 7. Further, the output of the temperature sensor is output to a 20 ° C.-converted gas pressure calculating means 10 described later.

The memory 7 is divided into five blocks MA to ME, and each block is composed of N storage areas. That is,
The area MA stores N points of the gas pressure detected by the pressure sensor S1, and the area MB stores the N points of the gas pressure detected by the gas pressure sensor S2. Similarly, the area MC stores the gas pressure for N points detected by the gas pressure sensor S3, the area MD stores the gas pressure sensor S4, and the area ME stores the gas pressure for the N points detected by the gas pressure sensor S5. In each area, when new gas pressure data is generated, the data is stored as the latest data in P (N), and the stored data is pushed out one by one, and when the area is full, The data of P (1) is discarded. 8 is an integrating means for calculating an integrated value of the gas pressures of P (1) to P (N) for each of the areas MA to ME, and 9 is a division for obtaining an average value by dividing the integrated gas pressure by N. Means.
The result of the division is led to the 20 ° C. converted gas pressure calculating means 10,
Here, the gas pressure converted to 20 ° C. is calculated. Further, the calculation result is led to the determination means 11, where an accident, that is, abnormal overheating has occurred in the corresponding gas section when the output of the 20 ° C.-converted gas pressure calculation means 10 exceeds a predetermined threshold value. And outputs an accident occurrence signal to the accident point output means 12.

(E) Operation In the configuration shown in FIG. 1, a gas pressure equivalent to 20 ° C. is determined at 5:00 in the morning when the temperature difference between the tank outer wall temperature and the gas average temperature is minimized in one day. The pressure is stored in advance in a memory in the 20 ° C. converted gas pressure calculating means 10 and is updated daily. And each section A ~
The temporal average value of the pressure data of E is obtained from the output of the dividing means 9 and the 20 ° C.-converted gas pressure calculating means 10 obtains the 20 ° C.-converted gas pressure in each of the gas sections A to E. At this time, the above calculation is performed using the previously obtained rated pressure value at 5:00 in the morning. Then, a difference between the calculation results of the gas sections A to D through which the load current flows and the gas section E through which the load current does not flow is output to the determination means 11, and when the difference exceeds a predetermined gas pressure value. Then, it is determined that abnormal overheating has occurred in the corresponding gas section, and an abnormal heating occurrence signal is output to the alarm output means 12.

By monitoring the gas pressure difference between the gas compartment where no load current flows and the gas compartment where the load current flows as described above, error factors such as heating by direct sunlight and cooling by wind are monitored. I try to eliminate.

(F) Embodiment FIG. 2 is a block diagram of a control unit of the monitoring apparatus according to the embodiment of the present invention. The control unit according to the present embodiment is configured by a microcomputer system.

Total of five gas pressure sensor S1~S5 and the temperature sensor S _T
Detects the gas pressures of the gas compartments A to E and the temperature of the wall surface of the GIS container, respectively. These outputs are amplified to an appropriate level by the amplifier 5. Among them, the high-frequency component of the gas pressure data is removed by the low-pass filter 6. Each sensor output subjected to necessary signal processing is led to the multiplexer 21.

The multiplexer 21 passes data to the CPU 23 through the AD converter 22 at the subsequent stage while selecting each signal. The CPU 23 has a ROM 2 for storing application programs and the like.
4, and a RAM 25 including an area where sampling data of the gas pressure detected by the gas pressure sensor is stored, and the like,
The contact output circuit 26, the operation panel interface 27, and the AD converter 22 are connected by an internal bus. The contact output circuit 26 outputs an alarm signal when detecting an abnormal heating. The operation panel interface 27 has a display 28
And an operation panel 30 including input keys 29.

The RAM 25 has an area MA as shown in the memory 7 of FIG.
To ME, and sample data is stored in each area.

 FIG. 3 is a flowchart showing the operation of the CPU 23.

When the operation of the apparatus is started, first, in step n1, it is determined whether it is 5:00 am of the day. If 5 am proceeds to step n2 executes a subroutine PCONT for determining the rated pressure P _CONT. If it is not 5:00 am, the process proceeds to n3 and proceeds to the determination routine.

FIG. 3B shows the PCONT routine. The first n10, detects the gas pressure P ₅ of the temperature T ₅ and 5am the 5am at n11 at work. The detection of the gas pressure at n11 is N
Once done, the average value of the P ₅ in n12. Then, the rated pressure P _CONT for the day is calculated at n13. This P _CONT is obtained by the following equation. In general formula, P _CONT = P ₅ (1 + 0.005 × (20−T ₅ )) (1) For each container, P _CONT obtained by the above equation (1) is R
It is stored in the determined area of AM25 and returns.

 FIG. 3C shows a determination routine.

When this routine is entered, the temperature and gas pressure of the gas section at that time are first detected at n20 and n21. Then, the average value of the gas pressure data sampled N times is obtained in n22, and the deviation ΔP between the gas pressure of the gas section having the energizing element and the gas pressure without the energizing element is calculated in n23. The calculation of ΔP is performed by the following equation.

ΔP = P _20n −P _20B (2) Here, the 20 ° C. converted gas pressure of the n-th container is P _20n = P _n + P _CONT × 0.005 (20−T) of the reference container (container without a current-carrying element) The converted pressure at 20 ° C is P _20B = P _B + P _CONT × 0.005 (20−T), where P _CONT indicates the rated gas pressure obtained at 5:00 in the morning.

Then, a judgment of whether the deviation [Delta] P _n is greater than a predetermined threshold value [Delta] P ₀ at n24, larger
Proceeding to n25, a contact output signal for notifying the contact output circuit 26 of the abnormality is output, and an alarm is displayed on the display 28.

Note that the above determination routine shows the operation for a single gas section, but in practice, the above determination routine is performed for each gas section because of the switching operation of the multiplexer 21.

If the rated pressure at 5:00 am of each gas compartment is different, the difference is _added to or subtracted from P _20n and P _20B .

(G) Effects of the present invention As described above, according to the present invention, the gas pressure is used as information for monitoring abnormal overheating, so that the conventional GIS
The detection sensitivity can be increased compared to the conventional device that uses the temperature of the upper wall of the tank as information.Each gas compartment is affected by heating or cooling by wind due to direct sunlight, but no load current flows. Since the gas compartment is partially exposed to the outside air in the same manner as the gas compartment to be monitored for abnormal overheating, the above effects are equally affected.
Therefore, when judging the presence or absence of abnormal overheating by comparing the pressure data of the gas compartment where the load current does not flow and the pressure data of the gas compartment that is the target of other abnormal superheat monitoring,
The effects of the above-mentioned heating by direct sunlight and cooling by wind are negated, and abnormal overheating inside the GIS due to abnormal overheating of the conductor can be reliably monitored. Moreover, the rated gas pressure of each gas compartment at the reference temperature is obtained from the pressure of each gas compartment in a predetermined time zone and the temperature in the time zone, and the temperature at the time of abnormality determination, the pressure data of each gas compartment, Based on the rated gas pressure of the gas compartment,
Obtain gas pressure data at the reference temperature of each gas compartment,
Since the presence or absence of abnormal overheating is determined by comparing the pressure data at the reference temperature of the gas compartment where the load current does not flow with the pressure data at the reference temperature of the other gas compartments, the load current does not flow. Even if the configuration and the gas volume of the gas compartment and the other gas compartment are different, abnormal overheating can be reliably determined. In addition, according to the present invention, there is no need to provide a temperature sensor for each gas compartment, which causes problems such as an increase in the number of parts, new mounting work for them, and securing of a wiring path for a plurality of temperature sensors. Nor.

In addition, although each gas compartment is affected by heating by direct sunlight and cooling by wind, a part of the container is exposed to outside air in the gas compartment where no load current flows as well as the gas compartment which is monitored for abnormal overheating. Because of exposure, the above effects are equally affected. Therefore, when judging the presence or absence of abnormal overheating by comparing the pressure data of the gas compartment where the load current does not flow with the pressure data of the other gas compartments to be monitored for abnormal overheating, heating by direct sunlight or cooling by wind is used. In this way, it is possible to reliably monitor abnormal overheating inside the GIS due to abnormal overheating of the conductor.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a block diagram of a monitoring device according to the present invention,
FIG. 2 shows a block diagram of a monitoring device control unit of the embodiment,
FIGS. 3A to 3C are flowcharts showing the schematic operation of the CPU. S1 to S4 ... Pressure sensors.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Takanori Tsunoda, the inventor, 47 Nisshin Electric Co., Ltd., Umezu Takaune-cho, Ukyo-ku, Kyoto-shi (56) Reference JP-A-58-66520 (JP, A) JP-A-1 −252116 (JP, A) 60-190108 (JP, U)

Claims (1)

(57) [Scope of request for utility model registration] 1. A GIS internal abnormal overheat monitoring device having a plurality of gas compartments including a gas compartment in which an outer wall of each gas compartment is in contact with outside air and through which a load current does not flow, wherein a wall of the GIS is provided. A common temperature sensor, a pressure sensor for detecting gas pressure provided for each gas section, and a temperature difference between the tank outer wall temperature and the gas average temperature in one day detected by the pressure sensor. Means for obtaining a rated gas pressure of each gas compartment at a reference temperature from a pressure of each gas compartment in a predetermined time zone which is the smallest and a temperature measured by the temperature sensor in the time zone; and Based on the temperature measured by the sensor, the rated gas pressure of each gas section, and the pressure of each gas section detected by the pressure sensor at the time of abnormality determination, the reference temperature of each gas section And the pressure data at the reference temperature of the gas section where the load current does not flow is compared with the pressure data at the reference temperature of the other gas sections, and the presence or absence of abnormal overheating is determined based on the result. Determining means; and a GIS internal abnormal overheating monitoring device, comprising: