JP5225448B2 - Circuit breaker - Google Patents

Description

  The present invention relates to a circuit breaker monitoring system and its circuit breaker, and more particularly to a circuit breaker that enables checking of a monitoring program.

  FIG. 2 is a block diagram of a conventional circuit breaker monitoring system disclosed in, for example, Japanese Patent Laid-Open No. 2000-208007.

  In the figure, 1 is a circuit breaker, 2 is a display module, 3 is an internal communication bus for connecting the circuit breaker 1 and the display module, 4 is a central monitoring device, and 5 is a communication between the circuit breaker 1 and the central monitoring device 4. A first external communication bus 6 is used for communication, and 6 is a second external communication bus used for communication between the display module 2 and the central monitoring device 4.

The operation of the conventional circuit breaker monitoring system formed as described above will be described.
(1) The central monitoring device 4 stores in the memory (not shown) of the circuit breaker 1 with respect to the circuit breaker 1 via the first external communication bus 5 based on a monitoring program provided in advance. Set value of cutoff characteristics (shutoff pickup value), alarm set value (alarm is output when the specified value is reached), cutoff information (number of cutoffs, cutoff current, etc.) and current, voltage, power factor, power of circuit An instruction to output measurement data such as electric energy is issued.

(2) The circuit breaker 1 transmits the data requested from the central monitoring device 4 to the display module 2 via the internal communication bus 3.
(3) The display module 2 displays data and transmits the data to the central monitoring device 4.
If the display module 2 does not need to display data, the circuit breaker 1 transmits the data directly to the central monitoring device 4 via the first external communication bus 5.

JP 2000-208007 A

  In the conventional circuit breaker monitoring system, as described above, the central monitoring device 4 is provided with setting values, alarm setting values, breaking information and measurement data of the breaking characteristics obtained from the circuit breaker provided in the central monitoring device 4. The monitoring program is used to collect data such as measured values, alarm information, and interruption information, etc. of the current circuit, so when a new monitoring program is created or periodically When checking whether the monitoring program is normal, there is a problem that it is not possible to check whether the monitoring program operates normally unless a load current is actually applied to the circuit or voltage is not applied.

  As a countermeasure for this, a check signal is input to the arithmetic circuit unit of the circuit breaker 1 by using a tester device to generate a signal corresponding to the actual load current and a voltage corresponding to the voltage applied to the actual circuit. There is a method of checking the monitoring program by inputting, but in this case, it has the following problems.

(1) The tester device has a complicated configuration and high cost, and is easily affected by noise and the like. The value input from the tester device to the arithmetic circuit unit of the circuit breaker 1, the load current that actually flows through the circuit, The voltage actually applied to the electric circuit is different, so it is impossible to check with high accuracy.
(2) In the case of a system in which a plurality of circuit breakers 1 are connected, it takes time to check each circuit breaker. There was a problem.

  The present invention has been made to solve the above-described problems, and a highly accurate program for a circuit breaker monitoring system formed by a circuit breaker and a central monitoring device for monitoring the circuit breaker. The purpose of the check is to form the check with a simple configuration at a low cost and to carry out the check in a short time.

The circuit breaker according to the present invention includes a contact for opening and closing an electric current, a current detecting means for detecting the electric current, a voltage detecting means for detecting the voltage of the electric circuit, a current detected by the current detecting means and the voltage detecting means, and An A / D conversion circuit that converts voltage into a digital signal, a microcomputer that obtains the output signal of this A / D conversion circuit, performs an operation, and trips the contact to instruct the device. This microcomputer is connected to the A / D conversion circuit. Storage means for storing data for processing the input signal, check data corresponding to the current flowing through the electric circuit and the applied voltage, an operation state selection switch enabling output of the check data, and output from the microcomputer An external bus interface for communicating to a central monitoring device,
When the microcomputer receives an output command from the central monitoring device via the external bus interface when the operation state selection switch is in the closed state, the microcomputer transmits measurement data calculated based on the check data in the storage means.

  As described above, according to the present invention, whether or not the monitoring program is normal is checked using at least one of the check data and the measurement data calculated using the check data. A circuit breaker that can easily check the monitoring program is obtained.

It is a block diagram which shows the structure of the circuit breaker in Embodiment 1 of this invention. It is a block diagram which shows the structure of the conventional circuit breaker with a communication function.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a circuit breaker monitoring system according to Embodiment 1 of the present invention.

In the figure, 7 is an electric circuit, and 8 is a circuit breaker connected to the electric circuit 7.
The circuit breaker 8 converts the analog signal detected by the switching contact 9, the current detection means 10, the current conversion means 11, the voltage detection means 12, the current conversion means 11 and the voltage detection means 12 into a digital signal. An A / D conversion circuit 13 for conversion, a microcomputer 14 for calculating a signal output from the A / D conversion circuit 13, a tripping device 15 for operating the switching contact 9 by a signal output from the microcomputer 14, and a microcomputer 14 This is a storage means for storing data for processing a signal input from the A / D conversion circuit 13 and for storing check data for checking whether or not the monitoring program for processing these data is normal. Non-volatile memory 16, external bus interface 17 for communicating output from microcomputer 14 to central monitoring device 21 described later, An operation state for selecting whether the internal bus interface 18 for communicating the output from the network 14 to the display module 22 described later and the circuit breaker 8 are in a normal operation state (for example, the normal operation state is open) or a check state. The selection switch 19 is formed of a check data change switch 20 that enables the check data stored in the nonvolatile memory 16 to be changed in the closed state.

The relationship between the operation state selection switch 19 and the check data change switch 20 is as follows.
Switch 19 Switch 20
During operation Open When open check Closed When open check data changes Open Close

  Further, in the nonvolatile memory 16, interruptions such as interruption characteristic setting value data for operating the tripping device 15 in a predetermined operation time corresponding to the overcurrent flowing in the electric circuit 7, interruption history of the circuit breaker 8, etc. The trip signal is output from the information and the microcomputer 14 and the trip device 15 operates normally, the alarm signal is output, or the current flowing through the electric circuit 7 and the voltage applied to the electric circuit 7 are accurately measured. In order to check whether or not the current is present, data for checking the current corresponding to the actual load current and the voltage corresponding to the voltage applied to the actual electric circuit are stored.

  The current detection means 10 is formed by current transformers 10a, 10b, and 10c that detect currents in R, S, and T phases, and the current conversion means 11 is formed by current conversion circuits 11a, 11b, and 11c, and voltage The detection means 12 is formed by transformers 12a and 12b.

  21 is a central monitoring device that monitors data measured by the circuit breaker 8, 22 is a display module that displays data measured by the circuit breaker 8, and 23 is used for communication between the circuit breaker 8 and the display module 22. An internal communication bus 24 is a first external communication bus used for communication between the circuit breaker 8 and the central monitoring device 21, and 25 is a second external communication bus used for communication between the central monitoring device 21 and the display module 22. .

Next, the operation of the circuit breaker monitoring system according to the first embodiment formed as described above will be described.
First, the operation of a normal circuit breaker will be described.

(1) Open the operation state selection switch 19. (Check data change switch 20 is open)
(2) When the switching contact 9 is turned on by manual operation, a current is passed through the electric circuit 7.
(3) Current flowing through the electric circuit 7 is detected by the current transformers 10a, 10b, and 10c, and the detected current is output to the current conversion circuits 11a, 11b, and 11c.
(4) The current signals input to the current conversion circuits 11a, 11b, and 11c are converted into voltage signals and output to the A / D conversion circuit 13.

(5) The voltage applied to the electric circuit 7 is detected by the transformers 12a and 12b, and a voltage proportional to the detected voltage is output to the A / D conversion circuit 13.
(6) The current and voltage signals input to the A / D conversion circuit 13 are converted from analog to digital and input to the microcomputer 14.

(7) The microcomputer 14 processes the current and voltage digital signals input from the A / D conversion circuit 13, and compares the calculation result with the set value of the cutoff characteristic of the circuit breaker 8 stored in the nonvolatile memory 16. If the set value is exceeded, a trip signal is output from the microcomputer 14 to the trip circuit 15, and the trip circuit 15 operates to open the switching contact 9.
(8) Further, when the calculation result exceeds the alarm set value of the circuit breaker 8 stored in the nonvolatile memory 16, the microcomputer 14 outputs an alarm signal.

(9) Further, the microcomputer 14 calculates the voltage signal output from the A / D conversion circuit, calculates the power, the electric energy, the power factor, etc. based on the calculated current and voltage signals, and outputs the result. The data is transmitted to the display module 22 via the internal bus interface 18 and is also transmitted to the central monitoring device 21 via the external bus interface 17.
(10) The display module 22 displays each measurement value received from the microcomputer 14, alarm information, or data such as a blocking cause on a liquid crystal panel (not shown) or the like.

Next, an operation for checking whether or not the created monitoring program operates normally when a new monitoring program is created by the central monitoring device 21 will be described.
(11) The operation state selection switch 19 is closed. (At this time, the check data change switch 20 is open)
Alternatively, when the central monitoring device 21 issues a check command to the microcomputer 14 via the first external communication bus 24 and the external bus interface 17, the operation state selection switch 19 is closed.
(12) The central monitoring device 21 issues a check data and measurement data output command to the microcomputer 14 via the first external communication bus 24 and the external bus interface 17 based on the monitoring program.
(13) In this case, the microcomputer 14 does not calculate the current and voltage signals output from the A / D conversion circuit, and uses the check data stored in the microcomputer 14 software or the nonvolatile raw memory 16 in advance. It works in a simulated manner.

(14) Check data corresponding to the long-time trip current, short-time trip current, instantaneous long-time trip current, and alarm current, which are the setting values of the circuit breaker 8 breaking characteristics, from the nonvolatile memory 16 Are sequentially output to the microcomputer 14.
(15) The microcomputer 14 calculates the time for operating the tripping device 15 corresponding to the check data.

(16) When check data corresponding to a predetermined current (for example, 100 A as a reference current) and a voltage (for example, 100 V as a reference voltage) is output from the nonvolatile memory 16, the microcomputer 14 Calculates measurement data such as electric power, electric energy, and power factor based on the input signal.

(17) The above result is transmitted to the display module 22 via the internal bus interface 18 and displayed on a liquid crystal panel (not shown) or the like.
(18) The display module 22 transmits the measurement data such as the breaking characteristics, power, electric energy, and power factor of the circuit breaker 8 received from the microcomputer 14 to the central monitoring device 21 via the second external communication bus 25.
(19) The central monitoring device 21 executes the monitoring program using the transmitted check data and measurement data, and whether the monitoring program has been executed normally, whether it is a predetermined value (for example, measured with the reference current 100A as 100A) Check) or not.

  Note that data transmission to the central monitoring device 21 may be performed directly via the first external communication bus 24 instead of via the display module 22.

  In the above description, the microcomputer 14 outputs a plurality of signals such as the check data stored in the nonvolatile memory 16, the set value of the cutoff characteristic of the circuit breaker 8, and measurement data to the central monitoring device 21. However, any one signal may be implemented.

Next, a case where the check data stored in the nonvolatile memory 16 is changed will be described.
(21) The check data change switch 20 is closed. (At this time, the operation state selection switch 19 is left open)
The check data change switch 20 can be operated manually, and a signal is sent from the central monitoring device 21 to the microcomputer 14 via the external communication bus 24 and opened and closed using a relay or the like. You can also.

(22) The microcomputer 14 periodically or irregularly checks the open / close state of the check data change switch 20, and if it is in the closed state, the operation state selection switch 19 is opened and the above (12) to (18) are performed. The check operation is stopped, and new check data is input from the central monitoring device 21 via the first external communication bus 24 and the external bus interface 17 and stored in the nonvolatile memory 16.
The original check data stored in the nonvolatile memory 16 is replaced with newly input check data and stored in the nonvolatile raw memory 16.
(23) Thereafter, the operation state selection switch 19 is closed, the check data change switch 20 is opened, and the data transmitted to the central monitoring device 21 is performed in the same manner as the operations (12) to (18) described above. To check whether the monitoring program operates normally.

As described above, according to the first embodiment, the check of the monitoring program is performed using the check data, so that the check can be easily performed at low cost. In addition, a check by a check command from the central monitoring apparatus can be performed, and the check result can be confirmed in the central monitoring apparatus by transmitting the check result.
In a system formed by a plurality of circuit breakers, a check can be performed in a shorter time than when a conventional tester device is used.

  Also, check data including a signal corresponding to a current or voltage that is passed through the electric circuit is stored, and the check data is checked with the check data and the check result is displayed on the display module. As a result, the accuracy of checking the program is high, and the check can be performed at a low cost with a simple configuration.

7 electric circuit, 8 circuit breaker, 14 microcomputer (CPU),
16 Nonvolatile memory, 17 External bus interface,
21 Central monitoring device, 22 display module.

Claims (2)

Contacts for opening and closing the current of the electric circuit, current detecting means for detecting the electric current of the electric circuit, voltage detecting means for detecting the voltage of the electric circuit, and the current and voltage detected by the current detecting means and the voltage detecting means, respectively, as digital signals A / D conversion circuit for conversion, a microcomputer for obtaining an output signal of the A / D conversion circuit, performing calculation, and commanding the opening / closing of the contact to the device, and the microcomputer is input from the A / D conversion circuit Storage means for storing data for processing signals and check data corresponding to the current flowing through the electric circuit and applied voltage, an operation state selection switch for outputting the check data, and an output from the microcomputer An external bus interface for communicating to a central monitoring device,
When the microcomputer receives an output command from the central monitoring device via the external bus interface when the operation state selection switch is in the closed state, the microcomputer calculates measurement data calculated based on the check data in the storage unit. A circuit breaker characterized by transmitting.   The circuit breaker according to claim 1, further comprising a check data change switch that enables the check data to be changed.

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