JPS61198070A - Control current monitor device for circuit breaker - Google Patents

Abstract

PURPOSE:To make a control current monitor device inexpensive by providing a measuring means for measuring a waveform of a control current, on a control power source side from the first branch point of the control power source side of a control power source bus. CONSTITUTION:An expensive measuring means 60 provided with a current sensor, and a data recording device for sampling and quantizing an analog waveform of a control current which has been detected by said sensor, and also converting it to strings of a series of discrete numerical values and storing it is provided on a control power source 1 side from the first branch point P1, of a control power source bus 2 which is led out of the control power source land makes a tripping control current and a closing control current branch and supplies them to plural circuit breakers. In this way, all the circuit breakers can be decided by only one measuring means at all times, irrespective of the number of sets of the circuit breaker.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] This invention is directed to a system in which each of a plurality of circuit breakers to which a control current is branched and supplied from a control power bus derived from a common control power source is expected to operate normally. The determination of whether or not the circuit breaker can be detected is made by measuring the waveform of the control current supplied to the circuit breaker in the plurality of circuit breakers that are the target of this determination, and using this measured waveform as the circuit breaker that is the target of the determination. The present invention relates to a control current monitoring device that performs comparison with a reference waveform that should be obtained when a device operates normally.

[Prior art and its problems]

In recent years, demands for the reliability of power circuit breakers, which constitute one element of the power system, have been increasing more and more, and in response to this,
The development of preventive maintenance technology that constantly monitors the state of the circuit breaker and determines whether or not the circuit breaker can be expected to operate normally is being actively promoted.

Conventionally, a method as shown in FIG. 2 has been known as one of the methods for making this determination. The figure shows a method for determining whether the opening operation of the circuit breaker is performed normally, and the control lines 31, 32, .・・・
, 3n are connected to relay contacts 41, 42, . 52 , . . . , 5n are provided with measuring means 61 , 62 , .

Now, it is assumed that it is determined whether a circuit breaker equipped with a tripping coil 51 can be expected to operate normally, and when the control switch 81 connected in parallel with the relay contact 41 is closed, the tripping coil 51 A trip control current 11 flows through. Reference numeral 7 denotes a sensor for detecting this tripping control current, and a non-inductive resistor with a small resistance value or a Hall element using a magnetic field generated by the tripping control current is used. The current detected by the sensor 7 is sent to the data recording device 91.
In this device, the analog quantity of the input current waveform is sampled and quantized, converted into a series of discrete numerical values, and stored. This stored numerical value string is subsequently transferred to the arithmetic unit 100, subjected to necessary processing, and then stored in a storage device (not shown). By comparing this memorized content with the memorized content obtained by similarly processing the straw waste waveform that should be obtained when the breaker that is the target of the judgment operates normally, it is possible to However, when the difference △■ exceeds the allowable value ΔIo, there is a malfunction in the tripping mechanism that is started by the tripping control current, and therefore normal operation cannot be expected. It is judged that it cannot be expected.

As described above, in the conventional method, a measuring means including a sensor and a data recording device is arranged for each circuit breaker, making the control current monitoring device including an arithmetic device extremely expensive. Furthermore, when additional circuit breakers were installed, it was necessary to add new measurement means.

[Purpose of the invention]

This invention eliminates the aforementioned drawbacks. The purpose is to provide an inexpensive control current monitoring device.

[Key points of the invention]

This invention makes it possible to determine whether or not each of a plurality of circuit breakers to which a control current is branched and supplied from a control power bus derived from a common control power source can be expected to operate normally. A standard that should be obtained when the waveform of the control current supplied to the circuit breakers in the plurality of circuit breakers is measured, and the measured waveform is assumed to be that the circuit breaker that is the subject of the determination operates normally. In the control current monitoring device that performs comparison with a waveform, a measuring means for measuring the waveform of the tripping control current or the closing control current is provided on the control power source side from the first branch point on the control power source side of the control power source bus. Accordingly, the above object is attempted to be achieved using only one measuring means.

[Embodiments of the invention]

FIG. 1 shows an embodiment of an aIIc flow monitoring device constructed in accordance with the present invention. A control current sensor 7 is provided on the side of the control power supply 1 from the first branch point P of the control power supply bus 2 derived from the control power supply l, and the 'l1iI flow detected by this sensor is sent to the data recording device 90. In this device, the analog quantities of the input kagome shapes are sampled and quantized, converted into a series of discrete numerical values, and stored. This memorized numerical sequence continues to perform
After being transferred to the device 100 and undergoing necessary processing,
It is stored in a storage device (not shown). However, simply by storing the data in this way, it is not possible to distinguish which circuit breaker the stored contents belong to, so when processing the data in the data recording device (a), it is necessary to It must be clearly indicated whether it is a circuit breaker or not.

As is well known, a % circuit breaker is equipped with an auxiliary contact on its ground potential side that opens or closes in conjunction with the main contact to which high voltage is applied, so when the circuit breaker opens, For example, the b contact 101 which is closed by this operation,
102, -, 10n, the code transmitter 301 operates with a small current that does not affect the control current waveform detected by the sensor 7 from the control power supply 1 side 62, and transmits a code unique to each circuit breaker.゜If electric power is supplied to 302, . It is possible to easily distinguish which circuit breaker the data belongs to. That is,
The memory contents stored in the storage device (not shown) with this code are stored by similarly processing the reference waveform of the tripping control current that should be obtained when this circuit breaker operates normally. This makes it easy to compare the content with the original content.

In the explanations above, control switches 81 and 8 are used to determine whether or not the circuit breaker can be expected to operate normally.
2, ..., 13n was assumed to be operated, but
When the relay arranged in each circuit breaker operates and any of its contacts 41, 42,...t4n operates, the waveform of the control current of the operated circuit breaker is automatically measured. Since the waveform is compared with the reference waveform, it is determined whether the circuit breaker can operate normally during the next operation.

〔Effect of the invention〕

As described above, according to the present invention, a sensor detects a control current, and an analog waveform of the control current detected by the sensor is sampled and quantized, and a series of discrete An expensive measuring device equipped with a data recording device that converts the value into a string of numerical values and stores it, is used to control the branching and supplying of tripping control current and closing control current derived from the control power source to multiple circuit breakers. Since the control is installed on the source side from the first branch point on the control power supply side of the source bus, regardless of the number of circuit breakers that are subject to judgment, one
It is now possible to judge all circuit breakers using only one measurement means, and even if a circuit breaker is added, it is possible to judge the added circuit breaker by simply adding a code transmitter specific to the circuit breaker. Effects can be obtained.

In the above-described embodiment, a code transmitter that transmits a code unique to the circuit breaker is used to identify the circuit breaker that is the target of the 1 determination, but the B contacts 101, 102,
It is also possible to connect the negative terminals of - and lOn to the arithmetic device 100 by providing input terminals corresponding to the negative terminals in a ratio of 31 pairs, respectively, and to make the determination inside the arithmetic device 100. Of course, the advantage of this is that no additional equipment is required on the circuit breaker side.

It gives rise to It is clear that the present invention is also applicable to switching devices other than circuit breakers, such as load switches and disconnectors, whose opening or closing operations are controlled by the control AT flow 1.

[Brief Description of the Drawings] Fig. 1 is a circuit diagram showing an embodiment of a control current monitoring device according to the present invention, Fig. 2 is a circuit diagram showing an example of a conventional control current monitoring device, and Fig. 3 is a circuit diagram showing an example of a conventional control current monitoring device. FIG. 2 is an explanatory diagram showing a comparison between a basic waveform of a circuit breaker trip control current and a determined waveform. 1... Control power supply, 2... Control power supply bus, 90, 9
1, 92. ..., 9n...Measuring means, Pl...First branch point on the control power supply side.

Claims (1)

[Claims] 1) Determine whether or not each of the multiple circuit breakers to which control current is branched and supplied from the control power bus derived from the common control power source can be expected to operate normally. The waveform of the control current supplied to the circuit breaker among the plurality of circuit breakers is measured, and the measured waveform is used as the reference waveform that should be obtained when the circuit breaker that is the target of the determination operates normally. A control current monitoring device for comparison, characterized in that a measuring means for measuring the waveform of the control current is provided on the control power supply side from the first branch point on the control power supply side of the control power supply bus. Current monitoring device.