JP2002125312A - Electronic circuit breaker and regulator for tripping characteristics - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic tripping circuit and a regulator for circuit breaker, which can facilitate regulating work and has diagnostic functions as well. SOLUTION: This electronic circuit breaker 20 is provided with a memory section 29, which permits overcurrent tripping characteristic data to be written, and a regulating terminal section 31 for writing the data of the memory section 29 from the outside. The regulation terminal section 31 connected to IC 4, can monitor a current value I24, into which energizing current of a cable run 21 is converted. A regulator 40 is connected to the electronic circuit breaker 20 through the regulating terminal section 31 and adds a difference ΔI between the first current value I24 with IC 24 and a second current value I41 of the cable run with a highly precise CT 50 to the current parameters of overcurrent tripping characteristic data, for correcting the overcurrent tripping characteristics data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic circuit breaker having an electronic trip circuit.

[0002]

2. Description of the Related Art As an electronic circuit breaker of this type, for example, one disclosed in Japanese Patent Application Laid-Open No. 2000-113796 is known.

FIG. 5 is a block diagram showing a configuration of a conventional electronic circuit breaker. In FIG. 5, reference numeral 1 denotes an electric circuit of an electronic circuit breaker, 2 denotes a current detection CT for detecting an electric current flowing through the electric circuit 1, 3 denotes a rectifier circuit for rectifying the electric current input by CT2, and 4 denotes a rectifier circuit. 3 for converting the output of I.3 into an energized current value that can be processed by the microcomputer 5
Reference numerals C and 5 denote microcomputers, which illuminate an energizing current value input from the IC 4 with overcurrent tripping characteristic data set in the memory unit 9 and output a tripping signal according to the result. The overcurrent tripping characteristic data is obtained by converting a half-time characteristic of a so-called circuit breaker into data, and is determined by a current parameter and an operation time parameter. Reference numeral 6 denotes a trigger circuit for outputting a trigger signal for opening the opening / closing mechanism section 10 when a trip signal is input from the microcomputer 5, reference numeral 7 denotes a characteristic setting section for setting characteristics corresponding to the use state of the circuit breaker, and reference numeral 8 Is an adjusting unit for adjusting the variation of the tripping operation characteristic, and 9 is a memory unit for storing data.

In such an electronic circuit breaker,
Variations in the tripping operation characteristics of the circuit breaker mainly depend on individual components of the current detection CT2 other than the microcomputer 5 such as the current detection CT2, the rectifier circuit 3, the IC 4, the switching mechanism 10, and the like.

[0005]

In the conventional electronic circuit breaker, the microcomputer 5 outputs a trip signal to the trigger circuit 6 in light of preset overcurrent trip characteristic data. , Rectifier circuit 3, IC 4, opening and closing mechanism 10, etc.
There is a problem that the overcurrent tripping characteristics, particularly the long time-delay tripping characteristics, have a large variation if the initial setting is maintained because there are individual differences between the components. Therefore, in order to guarantee this accuracy, an actual current is supplied to the electric circuit 1 after assembling the electronic circuit breaker, and the adjustment unit 8 adjusts the tripping characteristics due to individual differences of these components within the guaranteed tolerance. For example, it is necessary to individually adjust by adjusting a trimmer, a fixed resistance, and the like. Alternatively, it is necessary to select high-precision parts in order to reduce individual differences.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a highly accurate electronic circuit breaker which can easily adjust trip characteristics and does not require component selection. And It is another object of the present invention to provide a tripping characteristic adjustment device that can easily adjust the tripping characteristics of an electronic circuit breaker.

[0007]

An electronic circuit breaker according to the present invention comprises: a current detector for detecting a current flowing through an electric circuit;
An opening / closing mechanism for energizing or interrupting the electric circuit by the opening / closing, a trigger circuit for giving an opening trigger to the opening / closing mechanism, and a memory for storing tripping characteristic data including a relationship between a current parameter and a tripping time parameter. An electronic circuit breaker comprising: a calculation unit for giving an operation command to the trigger circuit based on the energizing current value detected by the current detection unit and the tripping characteristic data; The trip characteristic data stored in the memory unit is corrected based on a difference between the detected current value and a second detected current value of the electric circuit by the high-precision current detection unit having higher detection accuracy than the current detection unit. It is configured so that

Further, the difference between the first detected current value and the second detected current value is tripped and added to the current parameter of the characteristic data.

The trip characteristic adjusting device according to the present invention includes a current detector for detecting a current flowing through the electric circuit, an opening / closing mechanism for energizing or interrupting the electric circuit by opening / closing the circuit, and an opening / closing mechanism for the opening / closing mechanism. A trigger circuit for giving a trigger, a memory unit for storing trip characteristic data including a relationship between a current parameter and a trip time parameter,
Based on the energizing current value detected by the current detection unit and the tripping characteristic data, a tripping characteristic of an electronic circuit breaker that adjusts the tripping characteristic of an electronic circuit breaker including an operation unit that gives an operation command to the trigger circuit. An adjustment device, which has higher detection accuracy than the current detection unit of the electronic circuit breaker,
And a high-precision current detection unit for detecting a current flowing through the electric circuit, a first detection current value by the current detection unit of the electronic circuit breaker, and a second detection current value by the high-precision current detection unit. And a comparison operation unit for obtaining a correction value of the trip characteristic data by comparing these input current values and writing the correction value to the memory unit via the adjustment terminal unit of the electronic circuit breaker. It is.

[0010]

FIG. 1 is a block diagram showing the configuration of an electronic circuit breaker according to Embodiment 1 of the present invention. FIG. 2 is a diagram for explaining the overcurrent tripping characteristic of the electronic circuit breaker of FIG. 1. The vertical axis represents the operation time t until tripping, and the horizontal axis represents the current I, which is expressed in logarithm. Reference numeral 20 denotes an electronic circuit breaker, which is an example of a three-phase four-wire system. 21 is an electronic circuit breaker 20
Reference numeral 22 denotes a current detection CT for detecting an energizing current flowing through the electric circuit 21, and 23 denotes a rectifier circuit for rectifying the energizing current input by the current detection CT22. 24 is IC
(Integrated circuit), which outputs a phase selection sampling circuit for selecting the input phase of the rectifier circuit 23 and a trigger signal for operating the trigger circuit 26 when the input value of the phase selection sampling circuit exceeds a predetermined value. (That is, a trigger signal is output when a large current flows instantaneously in the electric circuit 1) A current value I obtained by A / D (analog / digital) conversion of the output of the instantaneous circuit and the phase selection sampling circuit
₂₄ (a first current value) to the microcomputer 25; a constant voltage circuit for maintaining the input (current) from the rectifier circuit 23 at a constant voltage by, for example, a capacitor and a diode; , A drive power supply unit for supplying drive power to electronic circuits such as the microcomputer 25 and the memory unit 29. Note that a current detection unit is configured by the current detection CT22, the rectifier circuit 23, and the IC24. Reference numeral 25 denotes a microcomputer (arithmetic unit) which stores a current value inputted from the IC 24 in the memory unit 2.
Then, the trip signal is output in accordance with the overcurrent trip characteristic data set in step 9.

Here, as shown in FIG. 2, the overcurrent trip characteristic data is obtained by converting the half-time characteristic of a so-called circuit breaker into data. If it exceeds, the data indicates that the trigger circuit 26 is operated. In FIG. 2, I ₀₁ , I ₀₂ , and I ₀₃ are current values related to instantaneous trip, short time trip, and long time trip, respectively.
100A, 200A and 1000A. Also, t ₀₁ ,
t _02, t ₀₃ are each, long-time pull-off, short time limit tripping,
Operating time for instantaneous trip, 5 minutes, 0.1 seconds,
0.01 second.

Reference numeral 26 denotes a trigger circuit for outputting a trigger signal for opening the opening / closing mechanism 30 when a trip signal is input from the microcomputer 25. Reference numeral 27 denotes a characteristic corresponding to the use state of the electronic circuit breaker 20, for example. A characteristic setting unit for setting characteristics corresponding to the rated current of the electric circuit 21;
Reference numeral 29 denotes a rewritable memory unit for storing overcurrent trip characteristic data, for example, an EEPROM. An adjustment terminal unit 31 is provided on a housing of the electronic circuit breaker 20 and connected to an adjustment device 40 for changing overcurrent tripping characteristic data of the memory unit 29 from outside the electronic circuit breaker 20, for example, a connection. Connector. An adjusting device 40 corrects the overcurrent tripping characteristic data stored in the memory unit 29 and adjusts the overcurrent tripping characteristic of the electronic circuit breaker 20, and converts an input from the high-sensitivity CT50 into a current value. Current detection section 41, the detected current value I ₄₁ by the high-precision CT 50 input from the current detection section ₄₁ and the current detection CT 22
Depending on the comparison result detected current value I ₂₄ by, and a comparing unit 42 for correcting the overcurrent trip characteristic data. Reference numeral 50 denotes a high-precision CT having higher detection accuracy than the current detection CT 22.

Next, correction of the overcurrent trip characteristic data will be described. FIG. 3 is a flowchart for explaining the correction of the overcurrent tripping characteristic data of the electronic circuit breaker of FIG. FIG. 4 is a table illustrating an example of correcting the overcurrent tripping characteristic data of the electronic circuit breaker of FIG. The adjustment device 40 is connected to the adjustment terminal unit 31 when correcting the overcurrent tripping characteristic data, for example, during a test before shipping the product. Thereafter, a current is supplied to the electric circuit 21 of the electronic circuit breaker 20 (S10). At this time, the comparison operation unit 4 of the adjustment device 40
2 reads the electric current value I ₄₁ of an electronic circuit breaker 20 which is detected by a high-precision current detecting CT50 (S2
0). At the same time, the current I ₂₄ detected by the current detection CT 22 is read from the IC ₂₄ (S22).

Next, the comparison operation unit 42 determines that the current
₄₁ and obtains a difference [Delta] I = I ₄₁ -I ₂₄ of the energization current I ₂₄ (S3
0), the absolute value of the difference ΔI is compared with the magnitude of the predetermined value X (S32). That is, the current CT22, the rectifier circuit 23,
An error generated by an individual difference of the IC 24 or the like is detected. S
If the absolute value of the difference ΔI is equal to or larger than the predetermined value X according to S <b> 32, an error is displayed on an error display unit (not shown) of the adjustment device 40 (S <b> 34). At this time, it is determined that the electronic circuit breaker 20 has some abnormality. On the other hand, when the absolute value of the difference ΔI is less than the predetermined value X in S32, the difference ΔI is added to the current parameter of the overcurrent tripping characteristic data to correct the current parameter (S36), and is written in the memory unit 29 (S40). ).

By the corrections in S36 and S40, for example, the current values for the instantaneous trip, the short time trip, and the long time trip are obtained by adding ΔI to I ₀₁ , I ₀₂ , and I ₀₃ as shown in FIG. Value. At this time, the operation time parameter remains at the initial setting. In other words, instantaneous trip,
The current value for short time trip and long time trip is 100
A, 200A, 1000A, ΔI is-(minus) 5
At the time of A, the current values relating to the instantaneous trip, the short time trip, and the long time trip are respectively 95 A, 195 A,
995A. With this configuration, it is possible to easily adjust so as to suppress the variation in the tripping characteristics due to the individual component difference. Further, it is not necessary to adjust the trimmer, the fixed resistor, and the like by the adjusting unit, so that an electronic circuit breaker with high tripping characteristics and high accuracy can be obtained. In addition, since the difference ΔI is added to all the current parameters, it is possible to obtain an electronic circuit breaker having particularly high long-time tripping characteristic accuracy.

Further, in the electronic circuit breaker 20 which has already been shipped as a product and is actually operating, maintenance or failure diagnosis can be performed. The adjustment device 40 is connected to the adjustment terminal 31 of the electronic circuit breaker 20, the current parameter data of the overcurrent trip characteristic data of the memory unit 29 set at the time of shipment is read, and the difference ΔI is obtained in the same manner as described above. . When the absolute value of the difference ΔI is extremely large, that is, when the absolute value is equal to or more than the predetermined value X, a failure is diagnosed and the electronic circuit breaker 20 is replaced. When the difference ΔI = 0 or the absolute value of the difference ΔI is less than the predetermined value X, the current parameter of the overcurrent trip characteristic data is corrected. At this time, the original data, the correction value (difference ΔI), the correction date and the like are written and used as reference data for the next diagnosis.

The adjustment terminal 31 is connected to, for example, Devicene.
t, Interbus, Profibus, and other existing network protocols.
Has the same functions as the current detection section 41 and the comparison operation section 42, so that the adjustment terminal section 31 and the high-precision CT
The maintenance current or the failure diagnosis can be automatically performed by inputting the conduction current from 50 and performing S10 to S40 described above.
At this time, as the high-precision CT 50, a high-precision current detection CT 12 using an existing measurement CT or transducer may be used. Further, the example in which the current parameter is corrected based on the difference ΔI has been described. However, the current parameter may be corrected, or both the current parameter and the operation time parameter may be corrected.
In addition, although the overcurrent tripping characteristic has been described as an example of the tripping characteristic, another tripping characteristic such as an earth leakage tripping characteristic may be used. The adjusting device 40 is I
Since the input current value I ₂₄ by C24, may be provided circuitry and a display unit for appropriately monitoring the current value I _24.

[0018]

According to the present invention, there is provided an electronic circuit breaker comprising: a current detector for detecting a current flowing through an electric circuit; an opening / closing mechanism for energizing or interrupting the electric circuit by opening / closing the circuit; And a memory unit for storing tripping characteristic data comprising a relationship between a current parameter and a tripping time parameter, based on the energizing current value detected by the current detection unit and the tripping characteristic data, In the electronic circuit breaker provided with a calculation unit for giving an operation command to the trigger circuit, a first detection current value by the current detection unit and a high-precision current detection unit with higher detection accuracy than the current detection unit Second of electric circuit
Is configured to correct the tripping characteristic data stored in the memory unit based on the difference from the detected current value, so that the tripping characteristics can be easily adjusted, and high accuracy can be achieved without performing component selection. An electronic circuit breaker can be obtained.

Further, since the difference between the first detected current value and the second detected current value is added to the current parameter of the trip characteristic data, the trip characteristic can be easily adjusted.

The trip characteristic adjusting device according to the present invention includes a current detector for detecting a current flowing through the electric circuit, an opening / closing mechanism for energizing or interrupting the electric circuit by opening / closing the circuit, and an opening / closing mechanism for the opening / closing mechanism. A trigger circuit for giving a trigger, a memory unit for storing trip characteristic data including a relationship between a current parameter and a trip time parameter,
Based on the energizing current value detected by the current detection unit and the tripping characteristic data, a tripping characteristic of an electronic circuit breaker that adjusts the tripping characteristic of an electronic circuit breaker including an operation unit that gives an operation command to the trigger circuit. An adjustment device, which has higher detection accuracy than the current detection unit of the electronic circuit breaker,
And a high-precision current detection unit for detecting a current flowing through the electric circuit, a first detection current value by the current detection unit of the electronic circuit breaker, and a second detection current value by the high-precision current detection unit. And a comparison operation unit for obtaining a correction value of the trip characteristic data by comparing these input current values and writing the correction value to the memory unit via the adjustment terminal unit of the electronic circuit breaker. In addition, it is possible to obtain a tripping characteristic adjusting device that can easily adjust the tripping characteristics of the electronic circuit breaker.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an electronic circuit breaker according to Embodiment 1 of the present invention.

FIG. 2 is a diagram illustrating overcurrent tripping characteristics of the electronic circuit breaker of FIG. 1; 50

FIG. 3 is a flowchart illustrating correction of overcurrent tripping characteristic data of the electronic circuit breaker of FIG. 1;

4 is a table illustrating an example of correcting overcurrent tripping characteristic data of the electronic circuit breaker of FIG. 1;

FIG. 5 is a block diagram showing a configuration of a conventional electronic circuit breaker.

[Explanation of symbols]

Reference Signs List 20 electronic circuit breaker, 21 electric circuit, 22
Current detection CT, 23 rectifier circuit, 24 IC,
25 microcomputer, 26 trigger circuit,
27 characteristic setting section, 29 memory section, 30
Opening / closing mechanism section, 31 adjustment terminal section, 40 adjustment device, 41 current detection section, 42 comparison operation section, 5
0 High precision CT

Claims (3)

[Claims] 1. A current detector for detecting a current flowing through an electric circuit, an opening / closing mechanism for energizing or interrupting the electric circuit by opening / closing the electric circuit, a trigger circuit for giving an opening trigger to the opening / closing mechanism, a current parameter and tripping. A memory unit that stores tripping characteristic data having a relationship with a time parameter, and a calculation unit that provides an operation command to the trigger circuit based on the energizing current value detected by the current detection unit and the tripping characteristic data. A difference between a first detection current value detected by the current detection unit and a second detection current value of the electric circuit detected by the high-precision current detection unit having higher detection accuracy than the current detection unit. An electronic circuit breaker configured to correct the tripping characteristic data stored in the memory unit based on the following. 2. The electronic circuit breaker according to claim 1, wherein a difference between the first detected current value and the second detected current value is added to a current parameter of the characteristic data. 3. A current detector for detecting a current flowing through an electric circuit, an opening / closing mechanism for energizing or interrupting the electric circuit by opening / closing the circuit, a trigger circuit for giving an opening trigger to the opening / closing mechanism, and a current parameter and tripping. A memory unit that stores tripping characteristic data having a relationship with a time parameter, and a calculation unit that provides an operation command to the trigger circuit based on the energizing current value detected by the current detection unit and the tripping characteristic data. An adjustment device for a tripping characteristic for adjusting a tripping characteristic of an electronic circuit breaker, comprising: a detection accuracy higher than a current detection unit of the electronic circuit breaker; and a detection of a current flowing through the electric circuit. A high-precision current detection unit, a first detection current value by the current detection unit of the electronic circuit breaker, and a second detection current value by the high-precision current detection unit. A comparison operation unit for obtaining a correction value of the trip characteristic data by comparing these input current values, and writing the correction value to the memory unit via the adjustment terminal unit of the electronic circuit breaker. Adjustment device for tripping characteristics.