JP4715587B2 - Circuit breaker monitoring device and circuit breaker monitoring method - Google Patents

Description

  The present invention relates to a circuit breaker monitoring device and a circuit breaker monitoring method for monitoring a circuit breaker operating time of a gas insulated switchgear or the like.

In a circuit breaker monitoring device that monitors the operation time of a circuit breaker such as a conventional switchgear, excitation is used as a monitoring start point command in order to measure the time from the start of operation of the circuit breaker circuit breaker to completion. Signals such as current flowing through the coil and auxiliary contact signal are taken as signals for monitoring stop end point, and signals such as minute current flowing through the floating capacitor are fetched, and the operation time of the circuit breaker is calculated based on these signals.
JP-A-6-267365 (see page 2-3, FIG. 1)

  In a conventional circuit breaker monitoring device, a circuit breaker is used to capture a signal such as a current flowing through an exciting coil as a monitoring start point command, a signal such as an auxiliary contact signal, or a minute current flowing through a floating capacitor as a monitoring stop end point command. It is necessary to install a sensor for capturing these signals between them and to connect the signal lines.

  If it is a new circuit breaker, continuous monitoring is possible after sensor installation and signal line connection work at the time of installation. However, since the operation frequency of the circuit breaker is usually very low, there is a strong demand to perform sensor installation and wiring work only when the circuit breaker is operated.

  However, in the conventional circuit breaker monitoring device, when the sensor is installed or the signal line is connected, the circuit breaker may automatically operate in response to an abnormality in the power system. There is a problem that it is difficult to perform sensor installation and signal line connection work while the circuit breaker is operated.

  The present invention has been made to solve the above-described problems. In a portable circuit breaker monitoring apparatus, signal line connection work is simplified, installed in an existing circuit breaker, and operation time is calculated. A circuit breaker monitoring device that can be performed is obtained.

In the circuit breaker monitoring device according to the present invention, the circuit breaker command signal receiving unit for receiving the circuit breaker command signal indicating the operation start command time of the circuit breaker, and the circuit breaker that is not in contact with the circuit breaker and operates An acoustic sensor that detects an operation sound, and a calculation unit that calculates an operation time until the circuit breaker operates based on the interruption command signal received by the interruption command signal reception unit and the operation sound detected by the acoustic sensor It is.

  Since this invention judges the operation time of a circuit breaker based on the operation sound which the non-contact acoustic sensor detected, even if it is a portable circuit breaker monitoring apparatus, attachment work can be simplified. Therefore, in the attachment work with respect to the existing circuit breaker, there is an effect that the circuit breaker that is operating can be installed.

Embodiment 1 FIG.
FIG. 1 shows a system for a circuit breaker monitoring apparatus according to Embodiment 1 for carrying out the present invention. In FIG. 1, the circuit breaker monitoring device 1 of the present embodiment is installed at a position away from the circuit breaker 2 having the circuit breaker 21 by a predetermined distance. The circuit breaker monitoring apparatus 1 includes an acoustic sensor 11 such as a microphone that detects an operation sound when the circuit breaker 2 operates, a signal processing unit 12 that processes an operation sound signal detected by the acoustic sensor 11, and a circuit breaker control unit 3. The operation command b and the interruption command signal receiving unit 13 processed by the signal processing unit 12, the interruption command signal receiving unit 13 that receives the interruption command signal a for specifying and controlling the operation start time of the circuit breaker 2 from A calculation unit 14 that calculates an operation time until the circuit breaker operates based on the received break command signal a, and a determination unit 15 that determines whether the circuit breaker 2 is abnormal based on the operation time calculated by the calculation unit 14. Is provided.

  Next, operation | movement of the circuit breaker monitoring apparatus 1 comprised in this way is demonstrated. The circuit breaker 2 starts its operation in response to a pulsed cut command signal a from the circuit breaker control unit 3 as shown in the upper part of FIG. FIG. 2 shows the time change of the circuit breaker command signal a and the operation signal b described later. At this time, the break command signal a from the breaker control unit 3 is also output to the calculation unit 14 in the breaker monitoring device 1. Since the circuit breaker 2 blocks the circuit breaker 21, an operation sound for releasing the latch of the mechanical system and an operation sound during the main contact operation are generated thereafter. The acoustic sensor 11 detects the operation sound from these circuit breakers 2. FIG. 3 shows a temporal change in the sound level (in dB) of the operation sound detected by the acoustic sensor 11.

  Thereafter, the signal processing unit 12 generates a step-like operation signal b that rises from the time when the acoustic sensor 11 detects the operation sound during the main contact operation of the circuit breaker 2 as shown in the lower part of FIG. Output to. Here, the operation signal b is generated assuming that the time when the operation sound of the main contact operation is detected is the time when the sound level of the operation sound detected by the acoustic sensor 11 exceeds a predetermined threshold. The threshold value at this time is determined based on the sound level of impact during the main contact operation of the circuit breaker 2. Here, since the sound level of the impact during the main contact operation of the circuit breaker 2 is a sound level exceeding 120 dB, the threshold value is set to 80 dB, for example.

Next, the calculation unit 14 calculates the operation time of the circuit breaker 2 based on the circuit break command signal a transmitted from the circuit breaker control unit 3 and the operation signal b transmitted from the signal processing unit 12. The operation time calculation method will be described with reference to FIG. First, the rising time of the interruption command signal a is t1, the rising time of the operation signal b is t2, and the time when the breaker 2 is cut off is t3. As described above, the circuit breaker 2 starts to operate from the time indicated by the interruption command signal a, and an operation sound is generated during the main contact operation. Since the operation sound generation part of the circuit breaker 2 and the acoustic sensor 11 are located at a predetermined distance, the operation signal b rises from the time when the sound level of the operation sound of the main contact operation exceeds the threshold. Is delayed by the time to reach the acoustic sensor 11. Therefore, Formula (1) is established.
t1 <t3 <t2 (1)

Next, the time difference Δt1 between t1 and t2 is calculated by the equation (2).
Δt1 = t2−t1 (2)

Now, since the operation sound generation part of the circuit breaker 2 and the acoustic sensor 11 are located at a predetermined distance, the rising time of the operation signal b is the time when the operation sound during the main contact operation exceeds the threshold value. Is delayed by Δt2. Here, Δt2 is the time until the operation sound of the main contact operation reaches the acoustic sensor, that is, (t2-t3). Therefore, the distance between the operation sound generating unit of the circuit breaker 2 and the acoustic sensor 11 is L, air If the speed of the sound inside is v, it can be expressed by equation (3). Here, the speed of sound v in the air is assumed to be constant at 340 m / s. Further, the distance L between the operation sound generator of the circuit breaker 2 and the acoustic sensor 11 is measured in advance and is input to the calculator 14.
Δt2 = t2−t3 = L / v (3)

The time ΔT until the interruption command signal a from the circuit breaker control unit 3 rises and the main contact operates, that is, the circuit breaker 2 is interrupted, can be calculated using Equation (4).
ΔT = t3-t1
= (T2-t1)-(t2-t3)
= Δt1-Δt2 (4)

  Therefore, based on the rise time of the interruption command signal a, the time when the sound level of the operation sound detected by the acoustic sensor 11 exceeds the threshold, the speed of sound in the air, and the distance from the breaker to the acoustic sensor, It is possible to calculate the operation time until 2 operates.

  Further, in the above-described example, the signal processing unit 12 generates the step-like operation signal b that rises from the time when the acoustic sensor 11 detects the operation sound during the main contact operation of the circuit breaker 2, and transmits it to the calculation unit 14. However, it is not always necessary to generate such an operation signal b. That is, only the time t2 when the sound level of the operation sound detected by the acoustic sensor 11 exceeds a predetermined threshold may be output from the signal processing unit 12 to the calculation unit 14. Similarly, with respect to the interruption command signal a transmitted from the circuit breaker control unit 3, the interruption command signal receiving unit 13 receives only the time t1 when the interruption command signal a rises and transmits it to the calculation unit 14. Also good. Further, as is clear from the equation (2), the value necessary for calculating the operation time by the calculation unit 14 is not t1 and t2 itself but (t2−t1). You may make it the structure which transmits.

  Since the operation signal b is a step-like signal, the operation signal b may be reset at a predetermined time in order to detect the next operation sound of the circuit breaker 2. Furthermore, although the operation signal b has been described as a stepped signal that rises from time t2 when the sound level detected by the acoustic sensor 11 exceeds a predetermined threshold value, the signal that rises only when the threshold value is exceeded. It may be. By using such a signal, it is not necessary to reset the operation signal b.

  Moreover, although the closing operation of the circuit breaker 2 has been described above, the operation time can be calculated using the same method for the opening operation. In this case, the threshold value may be set to be different from the value in the closing operation.

  Next, the operation time T1 of the circuit breaker 2 calculated in this way, the current flowing through the exciting coil as the conventional monitoring start point command, the signal such as the auxiliary contact signal, and the minute current flowing through the floating capacitor as the monitoring stop end point command The operation time T2 calculated using the above signals is compared using FIG. FIG. 4 shows the relationship when the operating time T1 calculated by the circuit breaker monitoring apparatus 1 of the first embodiment is plotted on the vertical axis and the operating time T2 calculated by the conventional technique is plotted on the horizontal axis. The straight line graph in FIG. 4 is a graph of T1 = T2, and the points in the range 41 indicate the operation time during the opening operation, and the points within the range 42 indicate the operation time during the closing operation. T11 and T12 are the average value of the operation time during the opening operation and the average value of the operation time during the closing operation, which are calculated by the circuit breaker monitoring device 1 according to the first embodiment. T21 and T22 are the average value of the operation time during the opening operation and the average value of the operation time during the closing operation, respectively, calculated by the conventional method.

  The variation between the operation time T1 calculated in the circuit breaker monitoring device 1 according to the first embodiment and the operation time T2 calculated by the conventional method is 0.17 ms for the open operation and 0.20 ms for the open operation. In any case, the peak-peak is within 0.2 ms (± 0.1 ms). In addition, since the error of the normally calculated operation time is about ± 0.5 ms, it can be seen that the measurement accuracy in the circuit breaker monitoring device 1 according to the first embodiment is practically sufficient. .

  Next, the calculation unit 14 transmits the operation time ΔT thus measured to the determination unit 15, and the determination unit 15 compares this operation time ΔT0 obtained from the initial circuit breaker performance with a difference within a specified range. Whether or not there is an abnormality in the circuit breaker 2 is determined based on whether or not it is within. When the difference between ΔT and ΔT0 exceeds the specified range, it is determined that an abnormality has occurred in the circuit breaker 2, and an abnormality signal is output.

  As described above, in the circuit breaker monitoring apparatus 1 according to the first embodiment, the sensor is directly attached to the circuit breaker 2 or the signal lines are connected only by inputting the circuit break command signal a and the signal of the acoustic sensor 11. There is no need to do this, and the presence or absence of an abnormality can be easily determined even for the existing circuit breaker 2.

  Moreover, it cannot be overemphasized that the circuit breaker monitoring apparatus 1 in this Embodiment 1 mentioned above is realizable also as the circuit breaker monitoring method which performs the function of each structure in the step of the order as above-mentioned.

Embodiment 2. FIG.
FIG. 5 shows a system for a circuit breaker monitoring apparatus according to Embodiment 2 for carrying out the present invention. In the figure, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In the first embodiment, the speed of sound in the air used in the expression (3) is constant. However, as shown in FIG. 5, a temperature sensor 16 that measures the ambient temperature is provided in the circuit breaker monitoring device 1. It may be configured to correct the speed of sound in the air based on the ambient temperature.

Next, a method for correcting the speed of sound in the air will be described. The speed of sound v in the gas depends on the specific heat ratio κ, the gas constant R, and the gas temperature T, and is expressed as in equation (5).
v = sqrt (κRT) (5)
Moreover, when Formula (5) is simplified, it is expressed as Formula (6).
v = 331.5 + 0.6t (6)
Where t is the gas temperature (° C.).

  Since the sound velocity v is affected by the temperature in this way, the ambient temperature is measured by the temperature sensor 16 in the shut-off monitoring device 1 as shown in FIG. 5, and the value of the sound velocity v is corrected by the temperature at that time. By calculating the time until the operation sound of the main contact operation reaches the acoustic sensor 11 according to the equation (3) using the sound speed of ## EQU3 ## it becomes possible to calculate a more exact ΔT. In this case, since it is not necessary to directly attach the temperature sensor 16 to the circuit breaker 2 as well, it is possible to easily determine whether there is an abnormality in the existing circuit breaker 2 as in the first embodiment.

Embodiment 3 FIG.
FIG. 6 shows a system for a circuit breaker monitoring apparatus according to Embodiment 3 for carrying out the present invention. In the figure, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In the first embodiment, the interruption command signal a is used as a starting point for calculating the operation time of the circuit breaker 2. However, the operation of releasing the latch of the mechanical system for the operation of the circuit breaker 2 instead of the interruption command signal a. Sound may be used. In such a configuration, since the operation time can be calculated without using the cutoff command signal a, it is not necessary to provide the cutoff command signal receiving unit 13.

  In the circuit breaker 2, since the mechanical opening / closing operation of the main contact starts from the release of the latch, the signal processing unit 12 starts up from the time when the acoustic sensor 11 detects the operation sound when the circuit breaker 2 is unlatched. The operation signal may be generated and output to the calculation unit 14. Here, the operation signal is generated assuming that the time when the operation sound at the time of releasing the latch is detected is the time when the sound level of the operation sound detected by the acoustic sensor 11 exceeds a predetermined threshold. The threshold value at this time is smaller than the threshold value for detecting the operation sound of the main contact operation. Here, this threshold is set to 50 dB. The operation sound detection method and the operation signal b generation method during the main contact operation are the same as those in the first embodiment. For convenience of explanation, the operation sound of the main contact operation is the first operation sound, the operation sound when releasing the latch is the second operation sound, and the threshold value for detecting the first operation sound is the first operation sound. The threshold value, the threshold value for detecting the second operation sound is the second threshold value, the step-like signal rising from the time when the first operation sound is detected is the first operation signal, and the time when the second operation sound is detected A step-like signal that rises from the above is referred to as a second operation signal.

Next, the calculation unit 14 calculates the operation time of the circuit breaker 2 based on the first operation signal and the second operation signal generated by the signal processing unit 12. The operation time ΔT2 can be calculated by Expression (7), where t4 is the time when the first operation signal rises and t5 is the time when the second operation signal rises.
ΔT2 = t4-t5 (7)

  In the third embodiment, as is apparent from the equation (7), it is not necessary to use parameters of the sound speed and the distance to the circuit breaker 2 in order to calculate the operation time. Therefore, it is possible to calculate an operation time in which errors caused by these parameters are reduced.

  In addition, the first operation signal and the second operation signal have been described as step-like signals that rise from the time when the sound level detected by the acoustic sensor 11 exceeds the first threshold value or the second threshold value. The operation signal b may be a signal that rises only when the sound level exceeds the respective threshold value. With this configuration, signal processing in the signal processing unit 11 is simplified. In this case, since the second threshold is smaller than the first threshold, the second operation signal is not limited to when the second operation sound is generated, as shown in FIG. It becomes a signal that stands up even when the signal is generated. Therefore, it is necessary to use only a signal corresponding to the second operation sound. For this purpose, existing signal processing such as identification of the pulse width of the second operation signal and exclusive OR operation of the first operation signal and the second operation signal may be used.

It is a block diagram which shows the system of the circuit breaker monitoring apparatus which shows Embodiment 1 of this invention. It is a figure which shows the time change of the interruption | blocking command signal and an operation signal. It is a figure which shows the time change of the audio | voice level which the acoustic sensor detected. It is a figure which shows the operation time calculated with the circuit breaker monitoring apparatus of Embodiment 1 of this invention, and the operation time calculated with the conventional circuit breaker monitoring apparatus. It is a block diagram which shows the system of the circuit breaker monitoring apparatus which shows Embodiment 2 of this invention. It is a block diagram which shows the system of the circuit breaker monitoring apparatus which shows Embodiment 3 of this invention. It is a figure which shows the operation signal in Embodiment 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Circuit breaker monitoring apparatus, 11 Acoustic sensor, 13 Computation part, 14 Breaking command signal receiving part, 15 Determination part, 16 Temperature sensor, 2 Circuit breaker

Claims (7)

A shut-off command signal receiving unit for receiving a shut-off command signal indicating a command time for starting operation of the circuit breaker;
An acoustic sensor that is non-contacting with respect to the circuit breaker and detects an operation sound when the circuit breaker operates;
A circuit breaker comprising: an operation unit that calculates an operation time until the circuit breaker operates based on a circuit break command signal received by the circuit break command signal receiving unit and an operation sound detected by the acoustic sensor. Monitoring device. The computing unit is
The circuit breaker based on a command time for starting the operation of the circuit breaker indicated by a circuit break command signal received by the circuit break command signal receiving unit and a time when the level of the operation sound detected by the acoustic sensor exceeds a predetermined threshold The circuit breaker monitoring device according to claim 1, wherein an operation time until the operation is calculated. It has a temperature sensor that measures the ambient temperature,
The circuit breaker monitoring device according to claim 1, wherein the calculation unit corrects the operation time based on an ambient temperature measured by the temperature sensor. An acoustic sensor for detecting an operating sound when the circuit breaker operates;
Based on the time when the level of the operating sound detected by the acoustic sensor exceeds a first threshold and the time when the level of the operating sound exceeds a second threshold different from the first threshold A circuit breaker monitoring device comprising: an operation unit that calculates an operation time until the device operates. 5. The circuit breaker monitoring device according to claim 1, further comprising a determination unit that determines whether or not the circuit breaker is abnormal based on the operation time calculated by the arithmetic unit. A break command signal receiving step for receiving a break command signal from the circuit breaker;
An operation sound detection step of detecting an operation sound when the circuit breaker is operated by an acoustic sensor that is non-contact with the circuit breaker;
And a calculation step of calculating an operation time until the circuit breaker operates based on the interruption command signal received in the interruption command signal reception step and the operation sound detected in the operation sound detection step. Circuit breaker monitoring method. An operation sound detection step for detecting an operation sound when the circuit breaker operates;
Based on the time when the level of the operation sound detected in the operation sound detection step exceeds a first threshold and the time when the level of the operation sound exceeds a second threshold different from the first threshold A circuit breaker monitoring method comprising: an operation step of calculating an operation time until the circuit breaker operates.

Images