JP3599344B2 - Circuit breaker - Google Patents

Description

TECHNICAL FIELD The present invention relates to a circuit breaker, and more particularly, to a circuit breaker that can easily set any characteristics and is suitable for protecting an electric circuit.
BACKGROUND ART As a conventional technique of this type, for example, as disclosed in Japanese Patent Application Laid-Open No. 05-236633, a plurality of level discriminating means for detecting an output signal level of a current detecting means for detecting a current flowing through an electric circuit, It is known that the time limit generating means provided corresponding to each level discriminating means is configured to achieve characteristic protection coordination with higher-order equipment and lower-order equipment on the distribution system. I have.
Further, although not explicitly described in the above-mentioned prior art, the pickup level of the level discriminating means is adjustable, and the customer arbitrarily adjusts the level so that, for example, as shown in FIG. Has the long time trip property E, the short time trip property F and the instantaneous trip property G, the current level A at which the respective time elements of the long time trip property E and the short time trip property F operate, It is known that C is adjustable, and that the operating times B and D are also adjustable, thereby improving the margin for coordination.
In the conventional technology, the current detection pickup level or the time limit characteristic operation time level is adjustable to improve the margin for achieving protection coordination, but the characteristic shape of the time limit characteristic itself is cut off by the manufacturer's circuit. It was already fixed at the time of container design, and it was impossible to set an arbitrary characteristic shape when the customer used it. Therefore, when a power system is constructed with an arbitrary device configuration, there is a case where an optimal time limit characteristic for protection coordination cannot be obtained.
Also, in the prior art, the characteristic adjustment switch is provided on the circuit breaker main body. Therefore, when the number of adjustable items is increased so that the characteristic setting margin on the customer side can be improved, the number of the characteristic adjustment switches also increases. However, since the mounting space is limited, the number of adjustable items is limited.
DISCLOSURE OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and it is possible to set an arbitrary time limit characteristic curve desired by a customer without increasing the number of characteristic adjustment switches provided on the circuit breaker body. It is an object of the present invention to provide a circuit breaker that can easily take protection coordination.
The object is to provide a storage element for storing a plurality of selectable initial setting data in a circuit breaker, and to input data to a storage element in the circuit breaker from a characteristic setting device independent of a circuit breaker body. This is achieved by configuring to set and adjust the time limit characteristic shape.
Set and adjust the time limit characteristic shape of the circuit breaker arbitrarily by the characteristic setting device outside the circuit breaker, and transfer the data after setting and adjustment to the storage element inside the circuit breaker. Can eliminate the need for a switch for time limit characteristic adjustment. In addition, the number of adjustable items can be easily increased regardless of the mounting space.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a circuit configuration of a circuit breaker according to one embodiment of the present invention.
FIG. 2 is a sectional view showing a configuration of a main part of a circuit breaker according to one embodiment of the present invention.
FIG. 3 is a block diagram showing a circuit configuration of a system using the circuit breaker according to one embodiment of the present invention.
FIG. 4 is a perspective view showing a configuration of a system using a circuit breaker according to one embodiment of the present invention.
FIG. 5 is a block diagram showing a circuit configuration of a system characteristic setting device using a circuit breaker according to one embodiment of the present invention.
FIG. 6 is a characteristic diagram illustrating a method for setting characteristics of a circuit breaker according to one embodiment of the present invention.
FIG. 7 is an explanatory diagram of point cloud data used for setting characteristics of a circuit breaker according to one embodiment of the present invention.
FIG. 8 is a characteristic diagram illustrating a characteristic setting method in consideration of protection coordination of a circuit breaker according to one embodiment of the present invention.
FIG. 9 is a flowchart of a main routine of the circuit breaker according to one embodiment of the present invention.
FIG. 10 is a flowchart of data processing received from the circuit breaker characteristic setting device according to one embodiment of the present invention.
FIG. 11 is a flowchart of data processing of a system characteristic setting device using a circuit breaker according to one embodiment of the present invention.
FIG. 12 is a diagram showing an example of a display screen of a remote display function of the circuit breaker according to one embodiment of the present invention, and FIG. 12 (A) is a diagram showing a display screen of current information of the circuit breaker with ID number 1; FIG. 2B is a view showing a trip information display screen for the circuit breaker with ID number 2.
FIG. 13 is a characteristic diagram showing a method of setting a time limit characteristic of a conventional circuit breaker.
BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.
FIG. 2 shows a configuration of a main part of the circuit breaker 20 of the present embodiment. The housing 20a of the circuit breaker 20 has a substantially rectangular parallelepiped outer shape. In the housing 20a, a current transformer (hereinafter referred to as CT) 1 as a means for detecting a load current flowing through the electric circuit 15 is provided. A control device 18 for driving the tripping device 8 based on the detected current signal, a contact 14 provided between the power supply side 15a and the load side 15b of the electric circuit 15, a switching mechanism 25 for opening and closing the contact 14; A tripping mechanism 26 driven by the device 8 to trip the opening / closing mechanism 25, an arc extinguishing device 19 for extinguishing an arc generated at the time of interruption are stored, and a handle 27 for manually opening / closing the opening / closing mechanism 25 is provided in a housing. 20a protrudes from one surface. The contact 14, the opening / closing mechanism 25 and the handle 27 constitute opening / closing means, and the tripping device 8 and the tripping mechanism 26 constitute tripping means. The display unit 11 provided in the control device 18 is arranged so that the display content can be read from the surface of the housing 20a on which the handle 27 is provided. On this side, connectors 12a and 13a electrically connected to the data transmitting / receiving unit 12 and the ID setting unit 13 of the control device 18 so as to be connected to personal computers (hereinafter referred to as personal computers) 30 and 32 via a communication cable 40, respectively. Is provided.
FIG. 1 shows a block configuration of the control device 18. The conductor 15b on the load side of the electric circuit 15 penetrates the CT1, and the current signal detected by the CT1 is converted into digital binary data by the signal detector 2 and the A / D converter 3, and the microprocessor unit is used as arithmetic means. (Hereinafter referred to as MPU) 4. The MPU 4 is input to the storage element 5 from a plurality of selectable initial setting data stored in the storage element 5 as storage means and from characteristic setting devices 30 and 32 as characteristic setting means independent of the circuit breaker 20 main body. The calculated data is used to set and adjust the time limit characteristic shape so that a desired time limit characteristic is obtained. The output of the MPU 4 is supplied to the trigger circuit 7 or the alarm device driving circuit 17 according to the calculation result in the MPU 4. If the electric current in the electric circuit 15 is a current value that requires interruption of the electric circuit, the output of the MPU 4 is supplied to the trigger circuit 7, the trip device 8 is activated, and the opening and closing mechanism 25 is tripped by the operation of the trip mechanism 26. Then, the trip operation of the contact 14 of the circuit breaker 20 is performed. When the current of the electric circuit 15 reaches a predetermined ratio with respect to the current value at which the electric circuit needs to be interrupted, the output of the MPU 4 is supplied to the alarm device driving circuit 17 to control the alarm circuits 9 and 10, and the external alarm device 50 Is performed. The alarm device drive circuit 17 and the alarm circuits 9 and 10 constitute alarm means. The alarm circuits 9 and 10 are constituted by contact relays or semiconductor switching elements such as transistors and SCRs, and the external alarm device 50 notifies that the current value is approaching the trip value by light, sound or both. Specifically, a display device using a light-emitting element such as a discharge lamp, a light bulb or an LED as a display device using light, a display device such as a CRT, a plasma or a liquid crystal display, a buzzer display device using a sound, Bells, chimes, sirens, etc. that physically generate sound, oscillators, ICs that generate sound electronically, recorded sounds that generate sound, and sounds that are electronically synthesized by ICs, etc. Those that generate sound and those that generate sound by computer software are used. Any one of the above light or sound displays may be used alone, or any combination of light and sound, light and light, and sound and sound may be used.
An example of a system using the circuit breaker of the present embodiment will be described with reference to FIGS.
In this system, a characteristic setting device 30 or 32 is connected via a communication cable 40 as a transmission means connected to a connector 12a connected to a data transmission / reception section 12 of a circuit breaker 20, and an external alarm device is connected to the alarm circuit 9. 50 is connected.
The characteristic setting devices 30 and 32 may be, for example, a general personal computer 30 installed in a central monitoring room or the like that is remote from the installation location of the circuit breaker 20, or may be a portable personal computer 32. It is only necessary to have the communication interfaces 30b and 32b as communication functions, the mouse 31 or the keyboard 33 as a data input device, and a function capable of activating a dedicated program for characteristic setting. As shown in FIG. 5, these characteristic setting devices include a CPU for performing arithmetic processing, a RAM and a ROM for storing arithmetic data or a program, an input device such as a mouse 31 or a keyboard 33, and the like. It has communication interfaces 30b and 32b, a CRT 30a as a display device, a liquid crystal display 32a, and an external storage device 35 such as a floppy disk drive. The transmission means is not limited to the communication cable 40, but may be one using optical transmission using an optical fiber or transmission using wireless communication using visible light, infrared light, electromagnetic waves, or the like.
In this embodiment, since data is input from the characteristic setting devices 30 and 32, it is not necessary to add an adjustment switch on the circuit breaker main body side, and it is possible to prevent an increase in the size of the circuit breaker main body.
In setting the time limit characteristics of the circuit breaker, it is important to ensure consistency between the overcurrent withstand capability of the circuit breaker itself and the characteristic curve to be set.
In this embodiment, the data of the overcurrent tolerance of the circuit breaker itself is held in the storage element 5 in the circuit breaker 20, and when the characteristic is set by the characteristic setting device 30 or 32 outside the circuit breaker, As shown in FIG. 6, an unsettable area V is displayed on the displays 30a and 32a. The time limit characteristic is set by inputting the time limit characteristic curve data of the circuit breaker to be set in the region where the characteristics displayed on the displays 30a and 32a are to be set from the input device as an aggregate of point cloud data. The CPU obtains the time limit characteristic curve by first-order complementing the input point cloud data. Even if the point group data is intentionally set in the non-settable area V, the security can be ensured by setting a characteristic setting program of the characteristic setting device so as not to accept the data.
Specifically, on the displays 30a and 32a of the characteristic setting devices 30 and 32, as shown in FIG. 6, a coordinate system in which the ordinate represents the operation time and the abscissa represents the load current is displayed. Above, a non-settable area V in which characteristics should not be set due to the overcurrent withstand capability of the circuit breaker itself and a boundary line IV thereof are displayed. The setting of the characteristics is performed by setting and inputting a plurality of points on a coordinate system through which the time limit characteristic curve of the circuit breaker to be set passes outside the non-settable region V. That is, the time limit characteristic curve data of the circuit breaker is given as an aggregate of data (point group data) of points on a plurality of coordinate systems through which the time limit characteristic curve passes. In this embodiment, data of points where the respective characteristic curves bend on the time characteristic curve III of the circuit breaker and the characteristic curves II and I of the alarm circuit output are given as point cloud data. The alarm circuit output characteristic I is an alarm with a low degree of urgency. When the circuit current reaches a predetermined ratio with respect to the current to be interrupted, an alarm device such as an indicator light to which this output is supplied is operated, and the alarm circuit output characteristic II is an alarm with a high degree of urgency, which activates an alarm device such as an electronic sound generator to which this output is supplied when the circuit current increases and approaches the current to be interrupted. In the example of FIG. 6, the alarm circuit output characteristic I and the alarm circuit output characteristic II intersect when the load current is around 100% of the rated current. However, such a setting is originally not preferable. In this embodiment, since the characteristic curve is displayed on the display 30a or 32a, in such a case, the alarm circuit output characteristic I and the alarm circuit output characteristic II may be reset so as not to intersect while checking on the display. . The time limit characteristic curve III of the circuit breaker is set so as not to cross any of the boundary line IV of the non-settable area V and the alarm circuit output II.
The point cloud data set in this way is represented by a set of data in which current point data on the load current axis and corresponding operating time point data on the operating time axis are paired as shown in FIG. . When setting the time limit characteristics for the circuit breaker, the collective data is transferred from the characteristic setting devices 30 and 32 to the circuit breaker 20 by data communication via the communication cable 40. In the circuit breaker 20, the received collective data is once stored in the storage element 5 and expanded on the RAM in the MPU 4 so as to be subjected to time limit characteristic calculation. As the storage element 5, for example, an EEPROM is used. By storing the program for restoring the characteristic curve from the point cloud data into the storage element 5, the MPU 4 can restore the point cloud data to the characteristic curve even if the point cloud data is directly given in the set table format as shown in FIG. Can be.
By storing the data of the devices connected to the upper and lower levels in the external storage device 35 of the characteristic setting devices 30 and 32, it is possible to confirm the protection coordination with the devices connected to the upper and lower levels when setting the characteristics of the circuit breaker. Can also be done easily. That is, as shown in FIG. 8, for example, a thermal characteristic curve VI of a higher-level device and an operating characteristic curve VIII of a lower-level device are stored, and these data are displayed when the characteristics of the circuit breaker are set. By displaying on the same screen of 30a and 32a and inputting the point group between them and setting the characteristic curve VII, it is possible to easily perform the characteristic setting while confirming the protection coordination. Become.
The flow of setting the characteristics of the MPU 4 will be described with reference to FIGS.
FIG. 9 shows a main routine for setting characteristics. The process starts in step 100, sets a time limit characteristic in step 101, and clears a characteristic reset flag in step 102. Next, in step 103, it is determined whether or not the characteristic resetting flag is set. If the flag is set, the flow returns to step 101 to set the reduction characteristic again, and then proceeds to step 102 to clear the characteristic resetting flag. And the process proceeds to step 103. In step 103, it is determined whether or not the characteristic resetting flag is set, and if the flag is not set, control is performed according to the time limit characteristic set in step 101, and the process returns to step 103 and the characteristic resetting flag is set to YES or NO. Proceed to step 101 or step 104.
FIG. 10 shows a flow of an interrupt process when data is received from the characteristic setting device. If there is an interruption of data reception in step 200, it is determined in step 201 whether reception of all data has been completed. If all data has not been received, the process proceeds to step 202, and the process ends. If all data has been received, the process proceeds to step 211, where it is determined whether or not data in the characteristic setting impossible area has been requested from the characteristic setting device. If the data of the characteristic setting impossible area has been requested, the process proceeds to step 212, the data of the characteristic setting impossible area is transmitted, the process proceeds to step 213, and the process ends. If the data of the property setting impossible area is not requested, the process proceeds to step 221 to determine whether or not the property setting point group data has been received. If the characteristic set point group data has been received, the process proceeds to step 222, where the point group data is complemented to set the characteristic. Next, the routine proceeds to step 223, where the characteristic reset flag is set, the routine proceeds to step 224, and the processing is terminated. If the characteristic set point group data has not been received, the process proceeds to step 231 to determine whether state information is requested. If the status information has been requested, the process proceeds to step 232, where the status information of the circuit breaker is transmitted, and the process proceeds to step 233 to end the process. If the status information has not been requested, the process proceeds to step 240, and the process ends.
FIG. 11 shows a flow of processing of the characteristic setting device at the time of characteristic setting. The process starts in step 300, and in step 301, it is determined whether or not the mode is the characteristic setting mode. If it is the characteristic setting mode, the process proceeds to step 311 to transmit a code for requesting the data in the characteristic setting impossible area to the circuit breaker. Next, the process proceeds to step 312, where it is determined whether data reception is completed. If the data reception is not completed, the process returns to step 312 again. If the data reception is completed, the process proceeds to step 313 to read the characteristic data of the device connected to the upper or lower device from the external storage device 35. Next, the process proceeds to step 314, where the input of the characteristic data of the circuit breaker is received, and this data is displayed. Next, proceeding to step 315, it is determined whether or not the characteristic setting data is to be transmitted to the circuit breaker. If not, the process returns to step 314. When transmitting, the process proceeds to step 316 to transmit data. Next, the routine proceeds to step 317, where it is determined whether or not the characteristic setting mode has ended. If not, the process returns to step 314;
If it is not the characteristic setting mode in step 301, the process proceeds to step 302 to determine whether the mode is the state information display mode. If it is in the state information display mode, the process proceeds to step 321 to transmit a code for requesting the state information to the circuit breaker. Next, the process proceeds to step 322, where it is determined whether the reception of the status information data is completed. If the data reception has not been completed, the process returns to step 322 again. If the data reception has been completed, the process proceeds to step 323 to display the state information of the circuit breaker. Next, the routine proceeds to step 324, where it is determined whether or not the status display mode has ended. If not, the process returns to step 323;
In this embodiment, the MPU 4 of the circuit breaker 20 incorporates a program for returning the requested information in response to an information transfer request from an external device, and the circuit breaker 20 has a data communication function. For example, the state of the circuit breaker 20 after the start of energization can be remotely monitored by the characteristic setting devices 30 and 32. In this case, an ID number is assigned to each circuit breaker, and when a plurality of circuit breakers are connected to the characteristic setting device, a different ID number is given to each circuit breaker.
For example, with respect to the circuit breaker 20, a request for transferring current information is made from the characteristic setting device 30 to the circuit breaker with ID number 1 and a request for transferring trip information is made to the circuit breaker with ID number 2. In this case, as shown in FIGS. 12A and 12B, the state information of the circuit breaker with ID number 1 and the state information of the circuit breaker with ID number 2 are displayed on the display 30a of the characteristic setting device 30 at that time. Can be displayed.
Further, when the condition for generating the alarm signal is satisfied by the set alarm characteristic, the circuit is operated by the data communication function independently of driving the alarm circuits 9 and 10 provided in the circuit breaker 20. An alarm signal code can also be transmitted from the circuit breaker 20 to the characteristic setting devices 30, 32 or an external monitoring device.
INDUSTRIAL APPLICABILITY According to the present invention, the degree of freedom in setting the time limit characteristic of the circuit breaker can be easily expanded, and an effect that optimum protection coordination can be easily obtained is obtained.
In addition, since the data communication function is built in, it is possible to cope with an information network.

Claims (6)

And detecting means of the load current flowing through the path, and closing means for opening and closing the path, any and characteristic setting means for data is input to set the time characteristics, storage means for storing the input data in the characteristic setting unit When, performing the tripping of said switching means based on the output of the operational means and, said computing means for generating an output in accordance with the set time characteristics sets the time characteristics based on the data stored in the storage means tripping comprising means to display the setting impossible region on the display at the time of performing the characteristic setting in the circuit breaker externally of the characteristic setting unit, the calculating means on time characteristics curve inputted from the characteristic setting unit A circuit breaker configured to set a time limit characteristic based on data of a plurality of points. The characteristic setting means is provided independently of the main body of the circuit breaker, and data input to the characteristic setting means is configured to be input to the arithmetic means via transmission means. The circuit breaker according to claim 1. Means for detecting the load current flowing in the electric circuit, opening / closing means for opening / closing the electric circuit, characteristic setting means for inputting data for setting an arbitrary time limit characteristic, and storage means for storing data input to the characteristic setting means When an arithmetic means for generating an output in accordance with the set time characteristics sets the time characteristics based on the data stored in the storage means, when performing characteristic setting in the circuit breaker externally of the characteristic setting unit An alarm unit for displaying an unsettable area on a display and generating an alarm output based on the output of the arithmetic unit is provided. The arithmetic unit includes a plurality of points on the time-limit characteristic curve input from the characteristic setting unit. A circuit breaker characterized in that a time limit characteristic is set based on data. The characteristic setting means is provided independently of the main body of the circuit breaker, and data input to the characteristic setting means is configured to be input to the arithmetic means via transmission means. The circuit breaker according to claim 3. And detecting means of the load current flowing through the path, and closing means for opening and closing the path, any and characteristic setting means for data is input to set the time characteristics, storage means for storing the input data in the characteristic setting unit When, performing the tripping of said switching means based on the output of the operational means and, said computing means for generating an output in accordance with the set time characteristics sets the time characteristics based on the data stored in the storage means a tripping unit, to display the setting impossible region on the display at the time of performing the characteristic setting in the circuit breaker externally of the characteristic setting unit, the alarm output before operation of the means described above trip on the basis of the output of the arithmetic means Alarm means for issuing, and the arithmetic means is configured to set the time limit characteristic based on data of a plurality of points on the time limit characteristic curve input from the characteristic setting means. Circuit breaker according to symptoms. The characteristic setting means is provided independently of the main body of the circuit breaker, and data input to the characteristic setting means is configured to be input to the arithmetic means via transmission means. The circuit breaker according to claim 5.

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