JP7374568B2 - Breaker abnormality detection system - Google Patents

Description

Embodiments of the present invention relate to a circuit breaker abnormality detection system that detects an abnormality in a circuit breaker capacitor tripping device.

In power systems such as factories, circuit breakers are used to interrupt load currents, fault currents, short-circuit currents, etc. flowing in the main circuits of various devices. In addition to cases where the circuit breaker is supplied with control power from a DC power supply, control power may be supplied from an AC power supply without providing a DC power supply, and there are also cases where a combination of these is used (Patent Document 1) ). When using AC power as a control power source without installing a DC power supply, a capacitor tripping device can be used to simply convert AC voltage into DC voltage and use it as a control power source, and the circuit breaker operation circuit installed in the circuit breaker can be used as a control power source. to open the circuit breaker contacts.

In the case of a device that uses a circuit breaker to control operation and shutdown, if the circuit breaker fails or deteriorates, there is a risk that the device will not be able to start or stop operation in a timely manner. For example, if the capacitor tripping device itself malfunctions or deteriorates, control power cannot be supplied to the circuit breaker operation circuit, and the circuit breaker cannot cut off the power supply to the main circuit. It will be necessary to shut off the upper power supply, which may have a major impact on factory operations.

It is desirable to be able to detect failures or deterioration of capacitor tripping devices in advance, ensure safe operation of circuit breakers, and continue stable factory operations.

Japanese Patent Application Publication No. 3-165409

An object of the embodiments of the present invention is to obtain a circuit breaker abnormality detection system that can detect abnormalities such as failure and deterioration of a capacitor tripping device in advance.

A circuit breaker abnormality detection system according to an embodiment of the present invention includes an input voltage detector provided to detect input voltage, and a circuit breaker operation that operates to open a contact of the circuit breaker based on a trip command. The capacitor tripping device includes a capacitor tripping device that supplies control power to the circuit, and an abnormality determination circuit that detects an abnormality regarding the capacitor tripping device based on the input voltage detected by the input voltage detector. In the abnormality determination circuit, a first threshold and a second threshold having a lower value than the first threshold are set in advance. The abnormality determination circuit issues an alarm indicating that an abnormality exists on the input side of the capacitor tripping device when the input voltage has a value lower than the first threshold value, and when the input voltage has a value lower than the first threshold value, If the value is lower than the second threshold value, a trip command is sent to a higher-order circuit breaker provided in a system higher than the circuit breaker.

In this embodiment, a circuit breaker abnormality detection system is realized that can detect abnormalities such as failure and deterioration of the capacitor tripping device in advance.

FIG. 1 is a schematic block diagram illustrating a circuit breaker abnormality detection system according to an embodiment. FIG. 1 is a schematic block diagram illustrating a part of a circuit breaker abnormality detection system according to an embodiment. It is an example of a flowchart for explaining the operation of the circuit breaker abnormality detection system of the embodiment.

Embodiments of the present invention will be described below with reference to the drawings.
Note that the drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as those in reality. Furthermore, even when the same part is shown, the dimensions and ratios may be shown differently depending on the drawing.
Note that in the present specification and each figure, the same elements as those described above with respect to the existing figures are denoted by the same reference numerals, and detailed explanations are omitted as appropriate.

FIG. 1 is a schematic block diagram illustrating a circuit breaker abnormality detection system according to an embodiment.
As shown in FIG. 1, the circuit breaker abnormality detection system includes a capacitor tripping device 51 and an abnormality determination circuit 44.

The capacitor tripping device 51 is connected to the circuit breaker operation circuit 11 provided in the circuit breaker 1 and supplies control power to the circuit breaker operation circuit 11 . The capacitor trip device 51 is connected to the abnormality determination circuit 44 . The abnormality determination circuit 44 inputs an AC input voltage vin supplied to the capacitor tripping device 51 and an output voltage Vout which is a DC voltage outputted by the capacitor tripping device 51 as a control power source, and detects an abnormality in these voltage values. Determine the presence or absence of.

The circuit breaker 1 is provided between the AC power supply 100 and the load 3. In this example, a transformer 2 is provided between a circuit breaker 1 and a load 3. By connecting the contacts of the circuit breaker 1, power is supplied to the load 3 from the AC power supply 100. By opening the contacts of the circuit breaker 1, the power supply to the load 3 is cut off.

The circuit breaker operating circuit 11 operates upon receiving control power from the capacitor tripping device 51 . The circuit breaker operating circuit 11 is controlled by a control device provided on the monitoring panel 4. The control device is configured by, for example, a programmable logic controller. The control device of the monitoring panel 4 includes an operation command input section 41 and an operation/trip command generation section 42. The operation command input section 41 receives operation commands and trip commands from a manual switch or the like. The operation/trip command generation section 42 generates an operation command and a trip command for the circuit breaker operation circuit 11 according to the output of the operation command input section 41, and supplies them to the circuit breaker operation circuit 11.

When the operation command is generated by the operation/trip command generation unit 42, the circuit breaker operation circuit 11 operates to close the contacts of the circuit breaker 1. When a trip command is generated by the operation/trip command generation unit 42, the circuit breaker operation circuit 11 operates to open the contacts of the circuit breaker 1. For example, when the circuit breaker operating circuit 11 receives a trip command, it drives a trip coil (not shown) for opening the contacts of the circuit breaker 1 using the control power supplied from the capacitor tripping device 51. Then, the contacts of circuit breaker 1 are opened.

Although not shown, the operation/trip command generation unit 42 monitors the current flowing through the circuit breaker 1 and generates a trip command when the current flowing through the circuit breaker 1 reaches a predetermined value. The circuit breaker operating circuit 11 opens the contacts of the circuit breaker 1 in accordance with the generated trip command to protect the main circuit including the load 3 from excessive current.

FIG. 2 is a schematic block diagram illustrating a part of the circuit breaker abnormality detection system according to the embodiment.
FIG. 2 shows a simplified configuration of the capacitor tripping device 51.
As shown in FIG. 2, the capacitor trip device 51 of the circuit breaker abnormality detection system of the embodiment includes an input voltage detector 511 and an output voltage detector 512. The capacitor tripping device 51 includes a conversion circuit 5 that is connected to the AC power source 102 and converts it into a control power source for the circuit breaker 1 (denoted as a circuit breaker control power source in the figure) and outputs the control power source. The conversion circuit 5 includes a capacitor on the DC side, and can output control power for a certain period even if the AC power is cut off.

Input voltage detector 511 is connected to the input of conversion circuit 5 , and output voltage detector 512 is connected to the output of conversion circuit 5 . The input voltage detector 511 detects the input voltage vin input to the conversion circuit 5 and supplies it to the abnormality determination circuit 44 . The output voltage detector 512 detects the output voltage Vout output from the conversion circuit 5 and supplies it to the abnormality determination circuit 44.

Returning to FIG. 1, the explanation will be continued.
The abnormality determination circuit 44 is connected to a process monitoring device (HMI) provided outside the monitoring panel 4 via the control device of the monitoring panel 4. Furthermore, the abnormality determination circuit 44 is connected to a higher-order circuit breaker provided in the AC system higher than the circuit breaker 1 .

The abnormality determination circuit 44 executes abnormality processing based on the detected values of the input voltage vin and the output voltage Vout of the capacitor tripping device 51. The abnormality processing is set in a plurality of stages depending on the detected values of the input voltage vin and the output voltage Vout. When the abnormality determination circuit 44 determines that the degree of abnormality is minor, it issues an alarm to the HMI, and the alarm is displayed on the HMI. The alarm is not limited to text display on the monitor, but may also be outputted as audio or played back as a video.

When the abnormality determination circuit 44 determines that the degree of abnormality is severe, it issues an alarm, generates a trip command for the higher-order circuit breaker, and transmits the generated trip command to the higher-order circuit breaker. Open the upper circuit breaker.

FIG. 3 is an example of a flowchart for explaining the operation of the circuit breaker abnormality detection system according to the embodiment.
As shown in FIG. 3, when the operation/trip command generation unit 42 generates a closing command (operation command) for the circuit breaker 1, the abnormality determination circuit 44 starts an abnormality determination operation.

In step S1, the input voltage detector 511 measures the input voltage vin of the capacitor tripping device 51. The abnormality determination circuit 44 receives data on the measured input voltage vin from the input voltage detector 511. Note that the timing of measuring and transmitting the input voltage vin is set at a constant cycle set by a control network including a control device provided in the monitoring panel 4, for example. Further, the processing in each step described later is also performed at the set period.

In step S2, the abnormality determination circuit 44 compares the data of the measured input voltage vin with a preset threshold value VS. When the data of the input voltage vin is equal to or higher than the threshold value VS, the abnormality determination circuit 44 causes the process to transition to the next step S3. If the data of the input voltage vin is smaller than the threshold value VS, the abnormality determination circuit 44 shifts the process to step S6. In step S6, the abnormality determination circuit 44 determines that an abnormality regarding the capacitor tripping device 51 has been detected. The abnormality determination processing after step S6 will be described later.

In addition, in the determination in step S2, in order to avoid erroneous detection or malfunction of the input voltage vin, it is determined that the data of the input voltage vin is smaller than the threshold value VS for a predetermined period, for example, several cycles of the measurement period. If the process continues, it is preferable to transition to step S6. In this example, a timer T is provided to measure a predetermined period.

In step S3, the output voltage detector 512 measures the output voltage Vout of the capacitor tripping device 51. The abnormality determination circuit 44 receives data on the measured output voltage Vout from the output voltage detector 512.

In step S4, the abnormality determination circuit 44 compares the data of the measured output voltage Vout with a preset threshold value VC. If the data of the output voltage Vout is equal to or higher than the threshold value VC, the abnormality determination circuit 44 causes the process to transition to the next step S5. If the data of the output voltage Vout is smaller than the threshold value VC, the abnormality determination circuit 44 shifts the process to step S6.

In addition, in the determination in step S4, as in the case of step S2, the timer T indicates that the data of the output voltage Vout has continued to be smaller than the threshold value VC for a predetermined period, for example, several measurement cycles. It is preferable to measure at step S6 and move to step S6.

In step S5, the abnormality determination circuit 44 determines that the capacitor tripping device 51 is normal. The abnormality determination circuit 44 may output the determination result indicating normality to the HMI or the like. Thereafter, the above-described process is repeated until it is determined that there is an abnormality or a circuit breaker trip command is output.

A process performed when the abnormality determination circuit 44 determines that the capacitor tripping device 51 is abnormal in step S6 will be described.
In step S6, the abnormality determination circuit 44 has a second threshold value VS2 for the input voltage vin. The second threshold VS2 is set, for example, to a smaller value than the threshold VS. When the measured input voltage vin data is smaller than the second threshold VS2, the abnormality determination circuit 44 shifts the process to step S7, and in step S7 issues a trip command to the upper circuit breaker of the circuit breaker 1. generate. Note that it is preferable that the abnormality determination circuit 44 issues an alarm indicating that the upper-level circuit breaker will be tripped.

In step S6, if the data of the input voltage vin is equal to or higher than the second threshold value VS2, the abnormality determination circuit 44 shifts the process to step S8 and issues an alarm. Although the alarm in this case does not cause the upper circuit breaker to shut off other systems including the circuit breaker 1, it is preferable to display a message indicating that an immediate inspection or the like is required.

In step S6, the data of the input voltage vin is not limited to being compared with a threshold value, but the difference between data acquired at different times may be compared with a preset third threshold value. The data at different times can be, for example, data acquired in a cycle immediately before the currently acquired data. Further, by setting the threshold value of the input voltage vin to a value larger than the normal range of the input voltage vin, it is also possible to detect an open state on the input side of the capacitor tripping device as an abnormal state.

In the above description, a case has been described in which threshold values are set in multiple stages when detecting an abnormality in the input voltage, but comparison with threshold values in multiple stages may be performed when an abnormality in the output voltage occurs.

In the above description, the output voltage Vout is determined to be abnormal after the input voltage vin is determined to be abnormal. In this case, when installing, adjusting, and operating a circuit breaker system including the capacitor trip device 51, if the AC side of the capacitor trip device 51 is connected to the wrong connection, the It has the advantage of being able to detect defects. The abnormality determination of the output voltage Vout is not limited to the case where the abnormality determination of the output voltage Vout is executed after the abnormality determination of the input voltage vin, but the abnormality determination of the input voltage may be executed after the abnormality determination of the output voltage Vout. Moreover, the abnormality determination is not limited to the case where the abnormality determination of the input voltage vin and the output voltage Vout is performed sequentially, but it is also possible to perform the abnormality determination of each of the input voltage vin and the output voltage Vout in parallel. When abnormality is determined for the input voltage vin and the output voltage Vout in parallel, it is possible to distinguish which of the input voltage vin and the output voltage Vout is abnormal.

The effects of the circuit breaker abnormality detection system of the embodiment will be explained.
In the circuit breaker abnormality detection system of the embodiment, the input voltage vin and output voltage Vout of the capacitor tripping device 51 can be measured. Since the circuit breaker abnormality detection system includes the abnormality determination circuit 44, it is possible to detect an abnormality regarding the capacitor tripping device 51 based on the measured input voltage vin and output voltage Vout.

In the circuit breaker abnormality detection system of the embodiment, the input voltage vin and the output voltage Vout can be measured, respectively, and an abnormality can be determined sequentially or in parallel. In the case of successive abnormality determination, if the determination is started from the input voltage vin, if there is an abnormality in the capacitor tripping device 51, the quality can be quickly determined without determining the output voltage Vout. By sequentially determining whether the input voltage vin is abnormal or not and then determining whether the output voltage Vout is abnormal, it is possible to detect a malfunction in a mode in which an abnormality occurs on the output side even if the input side is normal.

If the input voltage vin and the output voltage Vout are determined to be abnormal in parallel, it is possible to determine whether there is an abnormality in the conversion circuit 5 of the capacitor tripping device 51, or whether there is a problem with the AC power supply 102 or the connection with the AC power supply 102, etc. It is also possible to distinguish and detect malfunctions related to the connection between the capacitor tripping device 51 and the circuit breaker 1.

In the circuit breaker abnormality detection system of the embodiment, the abnormality determination circuit 44 provides a plurality of threshold values for abnormality detection for the input voltage vin or the output voltage Vout. Therefore, processing can be set to distinguish between minor abnormalities and severe abnormalities, so that the circuit breaker 1 cannot be suddenly opened in situations that should be protected by the circuit breaker 1, such as a short circuit in the main circuit. It is possible to avoid affecting devices that should not be shut off by the upper level circuit breaker.

For minor abnormalities, if abnormality detection thresholds are set for the input voltage vin and the output voltage Vout, it will be possible to know in advance where the cause of the failure is during inspection, and it will be easier to restore the equipment to operation. The period can be shortened.

When detecting minor abnormalities, it is also possible to compare the difference between data at different times with a threshold value. There is also the benefit of being able to take precautions before an outbreak occurs.

In recent years, there has been a strong demand to increase factory operation rates and improve productivity. On the other hand, the circuit breaker's capacitor tripping device has a relatively simple circuit and structure, so there is little need to provide a specific protection circuit. However, capacitor tripping devices use capacitors, which are electrical components that can deteriorate, and the installation environment in factories where circuit breakers are used is often poor, making it easy for the capacitor tripping device itself to malfunction. However, there is also concern that deterioration and abnormalities may occur in wiring connections with circuit breakers, monitoring panels, etc. In the circuit breaker abnormality detection system of the embodiment, as described above, information useful for identifying the location of the malfunction can be output in the form of an alarm or the like. In addition, the circuit breaker abnormality detection system can also obtain trends in changes in the input voltage vin or output voltage Vout, so information that contributes to judgments such as when to replace parts, wiring, etc. can be collected. It also helps.

From the above, by introducing the circuit breaker abnormality detection system of the embodiment, sufficient operating time for the factory can be ensured, and even if a malfunction is detected by the circuit breaker abnormality detection system, the time required for restarting operations can be ensured. It becomes possible to shorten the period and contribute to improving the productivity of the factory.

According to the embodiment described above, it is possible to realize a circuit breaker abnormality detection system that can detect abnormalities such as failure and deterioration of the capacitor tripping device in advance.

Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included within the scope and gist of the invention, as well as within the scope of the claimed invention and its equivalents. Further, each of the embodiments described above can be implemented in combination with each other.

1 circuit breaker, 2 transformer, 3 load, 4 monitoring panel, 11 circuit breaker operation circuit, 44 abnormality determination circuit, 51 capacitor tripping device, 511 input voltage detector, 512 output voltage detector

Claims (4)

a capacitor tripping device that includes an input voltage detector installed to detect input voltage and supplies control power to a circuit breaker operation circuit that operates to open a contact of the circuit breaker based on a trip command;
an abnormality determination circuit that detects an abnormality regarding the capacitor tripping device based on the input voltage detected by the input voltage detector;
Equipped with
In the abnormality determination circuit, a first threshold and a second threshold having a value lower than the first threshold are set in advance,
The abnormality determination circuit issues an alarm indicating that an abnormality exists on the input side of the capacitor tripping device when the input voltage has a value lower than the first threshold;
A circuit breaker abnormality detection system that transmits a trip command to a higher-order circuit breaker provided in a system higher than the circuit breaker when the input voltage has a value lower than a second threshold value. The abnormality determination circuit includes:
Collecting the input voltage at a predetermined period,
The circuit breaker according to claim 1, which issues an alarm indicating that deterioration of the capacitor tripping device has started when a difference between the input voltages collected at different times is equal to or greater than a third preset threshold. Anomaly detection system. a capacitor tripping device that includes an output voltage detector installed to detect an output voltage and supplies control power to a circuit breaker operation circuit that operates to open a contact of the circuit breaker based on a trip command;
an abnormality determination circuit that detects an abnormality regarding the capacitor tripping device based on the output voltage detected by the output voltage detector;
Equipped with
In the abnormality determination circuit, a fourth threshold and a fifth threshold having a value lower than the fourth threshold are set in advance,
The abnormality determination circuit issues an alarm indicating that an abnormality exists on the output side of the capacitor tripping device when the output voltage has a value lower than the fourth threshold;
A circuit breaker abnormality detection system that transmits a trip command to a higher-order circuit breaker provided in a system higher than the circuit breaker when the output voltage has a value lower than a fifth threshold value. The device includes an input voltage detector provided to detect input voltage and an output voltage detector provided to detect output voltage, and operates to open the contacts of the circuit breaker based on a trip command. a capacitor tripping device that supplies control power to a circuit breaker operating circuit;
an abnormality determination circuit that detects an abnormality regarding the capacitor tripping device based on the input voltage detected by the input voltage detector and the output voltage detected by the output voltage detector;
Equipped with
In the abnormality determination circuit, a sixth threshold value regarding the input voltage and a seventh threshold value regarding the output voltage are set in advance,
The abnormality determination circuit issues an alarm indicating that an abnormality exists on the input side of the capacitor tripping device when the input voltage has a value lower than the sixth threshold;
A circuit breaker abnormality detection system that issues an alarm indicating that an abnormality exists on the output side of the capacitor tripping device when the output voltage has a value lower than a seventh threshold value.

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