JP4619101B2 - Circuit breaker with reclosing function - Google Patents

Description

The present invention relates to a circuit breaker with a reclosing function that automatically returns the circuit breaker to a closed state when the circuit breaker connected to the circuit is opened due to overcurrent, leakage current, lightning surge, etc. . In particular, the present invention relates to a circuit breaker with a reclosing function that can be installed at an unmanned base, etc., and can display the operation for each operation factor for the operation of the circuit breaker and can select whether or not the reclosing operation is performed for each operation factor. .

A circuit breaker with a reclosing function is usually installed in an unmanned base, etc., and is installed in a circuit breaker to automatically close the circuit when the circuit breaker is opened due to overcurrent, leakage current, lightning surge, etc. It acts to act on the operating handle to perform a closing operation.

As described in FIG. 1 of Patent Document 1 (Japanese Patent Laid-Open No. 2003-297217) shown in FIG. 12, the circuit breaker connected to the electric circuit and the operation handle of the circuit breaker are provided with a handle action unit. When the circuit breaker is opened, the circuit breaker is configured to include a reclosing means that acts on the operation handle to operate the electric circuit in a closed state.
An operation mechanism using a motor unit, a gear, a shaft, etc. is used for the operation of the handle action part of the reclosing means, and the gear part and the shaft are driven by the motor part, and the handle action part is applied to the operation handle to close the electric circuit. What is known to operate is known.

In addition, in such a circuit breaker with a reclosing function, it may be used in a mountainous area where the demand of power is expected to be low, and a high-voltage distribution line (6600V distribution line) from a substation is used. It is provided so as to intervene in a distribution line that is stepped down from a laid utility pole and distributed by a pole transformer provided on the utility pole. The distribution path is used in mountainous areas and the like, and since the line length becomes long, 400 V distribution that is not easily affected by a voltage drop is used. FIG. 9 shows a wiring connection diagram of a circuit breaker with a reclosing function in an electric circuit.

As shown in FIG. 9, the circuit breaker with a reclosing function is a part of the circuit breaker 100 indicated by a one-dot chain line in the drawing. The primary side of the circuit breaker with a reclosing function is provided with a transformer for stepping down from the high-voltage distribution line, and the secondary side is for stepping down to 100V or 200V to distribute power to a house or the like. The wiring is provided with a transformer.

For voltage step-down from the high-voltage distribution line, two pole transformers (6600V / 200V) are installed on the utility pole where the high-voltage distribution line (6600V) is laid, and the voltage input of the first and second transformers By connecting the output side in parallel to the electric circuit and connecting the output side in series, the connection is made so that the voltage across the output side is 400V.

The connection point on the voltage output side of the first transformer and the second transformer is grounded. The first transformer is provided with an output terminal for 100 V, and the control power from the ground point and the output terminal for 100 V of the first transformer to the reclosing means is acquired. In other words, the circuit breaker with a reclosing function needs to draw in the control power supply line in addition to the incoming and outgoing lines of the electric circuit, and it is necessary to draw / draw out the electric wires of the three paths in total. In addition, when installing a circuit breaker with a reclosing function, a dedicated distribution board was installed in the base station and installed in it.
JP 2003-297217 A (FIG. 1)

However, the conventional circuit breaker with a reclosing function described above is provided to automatically perform a reclosing operation when the circuit breaker operates.
Once the circuit breaker was activated, it would always be reclosed regardless of the operating factor.

Normally, when the circuit breaker operates unnecessarily, that is, when the circuit breaker operates due to lightning surge current, etc., the re-closing operation is automatically performed for the power supplier side and the power consumer side. Conveniently, for example, when the circuit breaker operates normally due to a continuous overcurrent in the circuit or a continuous short-circuit current, etc., it was provided to try again. There was a risk of increasing the number of overcurrent accidents and short circuit accidents, and there was a risk of circuit breakers breaking due to the load on the circuit breaker operation.

For this reason, if the circuit breaker immediately shuts down after the first reclosing operation as a protection against the occurrence of continuous overcurrent in the electric circuit or the continuous short circuit current, etc., it was shut down within 0.2 seconds. )), It is determined that an abnormal current such as overcurrent or short-circuit current continues to flow, and the program is controlled so that the subsequent reclosing operation is stopped (protection operation by the lock function). In situations where the IC operates normally, such as when an overcurrent, short-circuit current, or leakage current continues, it is possible to protect the circuit, the circuit breaker itself, or the human body due to an electric shock. It was provided.

In addition, when the reclosing operation is stopped as described above, that is, when the protection function by the lock function is activated, personnel are sent to the site where the circuit breaker with the reclosing function is installed, and the protection operation is performed. In addition to investigating the cause, it is necessary to release the lock function and reset the circuit breaker with reclosing function.

The cause of the operation at this time is unknown, so when investigating the cause, it may take time to investigate, and it takes time to restore power. There was a problem that supply was not performed.
That is, there is a problem that the time required for the survey increases and the work cost of personnel increases.

In addition, when the circuit breaker is activated, reclosing operation is performed. Depending on the magnitude of the overcurrent, for example, the circuit breaker may be a thermal electromagnetic type trip mechanism using a bimetal as the trip mechanism. When the circuit breaker having the above is used, there is a possibility that the reclosing operation may not be performed by performing the reclosing operation before the thermal deformation of the bimetal subsides. For this reason, if the reclosing operation fails and the circuit breaker immediately shuts off, the locking mechanism works, and there is a possibility that the subsequent reclosing operation is stopped. In this case, as in the case where the protective operation is performed by the lock mechanism as described above, there is a problem that work goes to the site where the person is installed to release the lock, which increases the work cost.

In addition, depending on the area and conditions where the circuit breaker with a reclosing function is installed, a large or small difference is expected in the frequency of lightning occurrence, and due to the characteristics of consumers, the possibility of electrical leakage and the occurrence of overcurrent are expected. If various conditions such as ease and whether or not a short circuit is likely to occur are known, it may be preferable to perform reclosing again depending on the situation, or conversely, once the circuit breaker is In some cases, it was preferable not to perform the reclosing operation.

Accordingly, the present invention has been made in view of such a situation, and can clearly display the operation factor of the circuit breaker, and can select whether or not to perform the reclosing operation for each operation factor. By optimizing the time control until the reclosing operation is performed according to the load condition in the electric circuit, the reclosing operation can be performed reliably during the operation of the circuit breaker, and the cause of the operation can be accurately determined. Depending on the installation location and environment of the circuit breaker with a reclosing function, it can be selected whether or not to perform the reclosing operation for each operating factor, and the circuit breaker with a reclosing function can be restored at the installation site. An object of the present invention is to provide a circuit breaker with a reclosing function capable of reducing personnel costs for the purpose.

The circuit breaker with a reclosing function of the present invention has an operation handle which is interposed in the electric circuit and operates to turn on and off the power supply to the load side electric circuit. Circuit breaker that shuts off the power supply to the circuit, and the power supply to the load-side circuit is stopped by the switching operation of the circuit breaker In this case, a reclosing function including a reclosing control unit and a reclosing mechanism unit that automatically act on the operation handle of the circuit breaker and turn on the circuit breaker is provided. In circuit breaker,
In the reclosing controller,
An operation factor determining means for determining a factor causing the circuit breaker to be turned off and outputting a driving signal for reclosing the operation circuit of the circuit breaker by inserting the operation handle of the circuit breaker into the reclosing mechanism;
Provided as means for determining the factor,
Overcurrent detection means for detecting overcurrent in the electric circuit;
A short-circuit current detecting means for detecting a short-circuit current in the electric circuit;
A leakage current detecting means for detecting a leakage current in the electric circuit;
Lightning surge current detection means for detecting lightning surge current in the electric circuit;
Tracking short-circuit current detection means for detecting the tracking short-circuit current;
Connected to the operating factor determining means ,
The operation factor is listed and an LED lamp is provided for each of the operation factors, and an operation factor display unit that can distinguish and visually recognize the factor that has operated most recently by lighting and displaying the factor that has operated most recently,
A reclosing operation selecting means provided next to the operation factor display section for selectively selecting whether or not to perform the reclosing operation for each operation factor ;
A reclosing operation frequency display section provided next to the reclosing operation selection means and displaying the number of reclosing operations for each operation factor;
Further, in the reclosing control unit,
Connected to the operating factor discrimination means, the magnitude of the overcurrent at the time of overcurrent detection is compared with the rated current of the circuit breaker, and based on the ratio between the magnitude of the overcurrent and the rated current, A circuit breaker with a reclosing function, characterized in that an automatic reclosing time setting unit for changing a time from the operation to the output of a drive signal for reclosing is provided.

According to such a configuration, in the circuit breaker with a reclosing function, when the reclosing operation is stopped, that is, when the protective operation by the lock function is activated, the circuit breaker with a reclosing function is installed. It is necessary to go to a certain site to investigate the cause of the protective action, and to release the lock function and reset the circuit breaker with reclosing function. The cause of the action is displayed on the display. Therefore, personnel can quickly cope with the problem after identifying the operating factors.

In addition, depending on the area and conditions where the circuit breaker with a reclosing function is installed, a large or small difference is expected in the frequency of lightning occurrence, and due to the characteristics of consumers, the possibility of electrical leakage and the occurrence of overcurrent are expected. If various conditions such as ease and whether a short circuit is likely to occur are known, it is preferable to perform reclosing again, or conversely, once the circuit breaker is activated In some cases, it is preferable not to perform the closing operation. Depending on the environment in which the circuit breaker with the reclosing function is installed, it is preferable to select whether to perform the closing operation for each operation factor in advance. This can reduce the cost of dispatching personnel and investigating the cause of operation.

Also, in the event that causes the circuit breaker to operate, determine at least whether the operation is due to overcurrent, short-circuit current, leakage current, or lightning surge current. It is something that can be done.

The front in addition to the determination of the operation factor of the circuit breaker of the predicate, can discrimination of whether this is the operation by the current tracking short circuit has attracted attention as a cause of fire burning in recent path, more precisely circuit breaker It is possible to identify the operating factors.

Also, like the case of using the circuit breaker having a tripping mechanism of the thermally activated electromagnetic using bimetal tripping mechanism of the circuit breaker performs the reclosing operation according to the size of the overcurrent It is possible to eliminate the case where the reclosing operation cannot be performed by performing the reclosing operation after the thermal deformation of the bimetal has been cured based on a predetermined condition determined in advance. If the circuit breaker fails and the circuit breaker immediately shuts off, the locking mechanism will not work and the subsequent reclosing operation will not be stopped, and personnel will go to the site where the circuit breaker with reclosing function is installed to release the lock. The work is unnecessary and the work cost can be reduced.

In the circuit breaker with a reclosing function of the present invention, the operation factor of the circuit breaker can be clearly displayed, and it is possible to select whether or not to perform the reclosing operation for each of the operation factors. By optimizing the time control until the reclosing operation is performed according to the state, the reclosing operation can be performed reliably during the operation of the circuit breaker and the cause of the operation can be accurately performed. Depending on the installation location and environment of the attached circuit breaker, it is possible to select whether or not the reclosing operation is performed for each operating factor, thereby reducing the labor cost for the restoration work of the circuit breaker with the reclosing function at the installation site. A circuit breaker with a reclosing function that can be provided can be provided.

A circuit breaker with a reclosing function according to the best embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows the internal structure of a circuit breaker with a reclosing function.

The circuit breaker 1 with a reclosing function is disposed in a housing 10 composed of a case in which equipment is disposed and a door that is opened and closed by a hinge mechanism so as to cover the opening of the case. Is done.

In the lower part of the case, there are provided an entry hole 21 for drawing in the power supply side electric wire 2 and an outgoing line hole 31 for drawing out the load side electric wire 3, and the power supply side electric wire 2 and the load side electric wire 3 penetrate through the case, respectively. It is configured to be arranged. Resin packing is attached to the inlet hole 21 and the outlet hole 31 for waterproofing in the case.

In the case, a circuit breaker 100 is disposed so as to be interposed in an electric circuit constituted by the power supply side electric wire 2 and the load side electric wire 3, and a circuit reclosing means 200 for the circuit breaker is arranged.

In the present embodiment, the circuit breaker 100 uses an earth leakage breaker, and the circuit breaker 100 includes a base having a base and a cover and has an insulating casing, and an electric circuit is provided in the casing. A plurality of contact devices for turning on and off, an opening / closing mechanism portion for acting on the contact device to open and close the contact device, a tripping mechanism acting on the opening / closing mechanism portion, and a contact acting on the opening / closing mechanism portion An operation handle 101 having an operation part protruding outside the housing is provided as well as an opening / closing operation of the apparatus, and a power supply side connection terminal portion 102 for connecting to an electric circuit at both ends of the circuit breaker housing. And a load-side connection terminal portion 103 is provided.

Further, the circuit breaker 100 has an operation state including an auxiliary switch configured using a micro switch that detects an on / off state of the contact device and an on / off state of the switching mechanism and a trip state in conjunction with the opening / closing mechanism unit. Detection means 111 is provided.

The microswitch used in the operation state detecting means 111 is always in a circuit-open state with the contact of the microswitch open, and an operation piece (not shown) provided so as to be interlocked with the contact of the microswitch. ) Is pressed to close the contacts of the microswitch, the circuit is closed.

The operation piece of the microswitch and the opening / closing mechanism of the circuit breaker 111 are connected to the opening / closing mechanism using an interlocking member (not shown), and the movement of the opening / closing mechanism is transmitted to the operation piece. When the device is in the open state, the interlocking member presses the operation piece and closes the contact of the micro switch to create a closed state in the circuit. When the contact device is in the closed state, the interlocking member is Is no longer pressed, and the contacts of the microswitch are opened, creating an open circuit.

For this reason, when the contact device of the circuit breaker 100 is opened, the operation state detection means 111 closes the contact of the microswitch, and the state changes from the open state to the closed state. As an output signal.

The circuit breaker 100 is provided with a leakage current detection means 112 including a zero-phase current transformer (ZCT) and a leakage detector. The leakage detector is electrically connected to the trip mechanism, and when a leakage current is generated in the circuit, the zero-phase current transformer (ZCT) is an unbalanced current in the current passing through the zero-phase current transformer. The leakage detector detects the occurrence of an unbalanced current based on the output from the zero-phase current transformer, and determines that a leakage current has occurred. When the magnitude of the leakage current exceeds a predetermined current value, an output signal is generated from the leakage detector toward the tripping mechanism, and the tripping mechanism that receives the output signal acts on the switching mechanism and contacts Open the device. The tripping mechanism may be a commonly used trip coil.

In addition, an output signal generated from the leakage detector is output to the trip mechanism and can be output to the outside of the circuit breaker, and is connected to a reclosing control unit 201 described later.

Current detection means 113 is provided on the load-side electric wire of the circuit breaker. The current detection means 113 comprises a current transformer (CT), and the current transformer is inserted through the load-side electric wire so that the electromotive force generated according to the magnitude of the flowing current changes. , The output of the voltage can be drawn to the outside. Based on the output from this current transformer, the magnitude of the current flowing through the electric circuit is detected by a reclosing control unit, which will be described later, and the occurrence of overcurrent, short circuit current, and tracking short circuit current is detected.

Now, the power supply side electric wire 2 drawn in from the inlet hole 21 is connected to the power supply side connection terminal portion 102 of the circuit breaker 100. The load-side electric wire 3 is connected to the load-side connection terminal portion 103 of the circuit breaker 100 and is drawn out of the housing from the output hole 31.

The energization in the electric circuit can be turned on and off by operating the operation handle 101 with the circuit breaker 100 to turn the circuit breaker on and off.

In the case, a circuit breaker reclosing means 200 is disposed. The reclosing means 200 mainly includes a reclosing control unit 201, a reclosing mechanism unit 202, and a transformer unit 203.

When the circuit breaker 100 is operated, the reclosing control unit 201 determines whether or not to perform the reclosing operation. When the circuit breaker 100 meets a predetermined condition, the reclosing mechanism unit 201 performs the reclosing operation. An operation signal is sent to 202.

The reclose mechanism 202 is driven by receiving an operation signal from the reclose controller 201 and acts on the operation handle 101 of the circuit breaker 100 to cause the circuit breaker 100 to reclose.

The transformer 203 is connected to the power supply side connection terminal 102 of the circuit breaker 100 on the power supply side, and connected to the reclose control unit 201 on the load side to transform the voltage of the electric circuit and is suitable for the reclose control unit. The voltage is stepped down. Specifically, the AC voltage (AC400V) of the electric circuit is stepped down to an AC voltage (AC100V) suitable for the control power supply of the reclosing controller by a transformer.

Further, the reclosing control unit 201 is provided with an operation factor display unit 2011, a reclosing operation selection unit 2012, and a reclosing operation number display unit 2013, which are provided so as to be visible from the outside when the housing door is opened. ing.

The operation factor display section 2011 lists factors that cause the circuit breaker to operate. In the present embodiment, each factor caused by overcurrent operation, short circuit current operation, leakage current operation, lightning surge current operation, and tracking short circuit current operation is listed. In addition, an LED lamp is provided, and the factor that has operated most recently is lit up so that the operating factor can be distinguished and visually recognized.

Further, next to the operation factor display unit 2011, reclosing operation selection means 2012 for selecting whether or not to perform the reclosing operation for each operation factor is provided, and whether or not to perform the reclosing operation. A changeover switch is provided so that can be selected alternatively.

Further, next to the reclosing operation selection means 2012, a reclosing operation number display unit 2013 for displaying the number of reclosing operations for each operation factor is provided. The re-closing operation number display unit 2013 is provided so that a past operation state can be grasped when a person goes to the installation location, such as when the operation of the circuit breaker with a re-closing function is locked and stopped. It has been.

In addition, the reclose control unit 201 is provided with a lock display unit 2014 and a reset switch unit 2015. The lock display unit 2014 stopped the subsequent operation when the circuit breaker immediately shuts off during the reclose operation. The reset switch unit 2015 is for releasing the lock of the reclosing control unit 201 in the locked state and returning it to the initial state.

Next, the connection between the reclosing means 200 and the circuit breaker 100 will be described with reference to FIG.
FIG. 2 is a block diagram of a circuit breaker with a reclosing function of the present invention.

The circuit breaker 100 and the reclosing means 200 are connected by various signal transmission communication lines and a handle action portion acting on the operation handle 101 of the circuit breaker.

As a communication line for signal transmission, an output line of an operation state detection unit 111 that detects an operation state of the circuit breaker 100, an output line of a current detection current transformer (CT), and a leakage current detection unit 112 And output lines. These communication lines are input to the calculation unit 2010 in the reclosing control unit 201 inside the control unit.

The calculation unit 2010 is connected to the operation factor display unit 2011, the reclosing operation selection unit 2012, the reclosing operation number display unit 2013, and the lock display LED 2014, and inputs and outputs various signals.

In addition, the calculation unit 2010 is provided with a drive signal sending unit for driving the reclosing mechanism unit 202. The signal sent from the drive signal sending unit is once inputted to the relay 2020 connected to the drive motor 2021, and the drive motor 2021 is driven by driving the relay. The operation unit 2010 is provided with an operation factor determination unit, and the circuit from the operation state detection unit 111, the leakage current detection unit 112, and the current detection unit 113 is processed in a comprehensive manner. The operating factor of the circuit breaker 100 is determined.

Next, regarding the method of determining the operation factor, the operation due to overcurrent, the operation due to the short circuit current, and the operation due to the tracking short circuit current will be described.

As shown in FIG. 3, the current detection means 113 provided on the load-side electric wire of the circuit breaker 100 includes a current transformer 1131, a current-voltage conversion circuit 1132, and a rectifier circuit 1133. . The current transformer 1131 detects the current flowing through the electric circuit and outputs an alternating current.

The current-voltage conversion circuit 1132 converts the alternating current output from the current transformer 1131 into an alternating voltage, and specifically converts it into a voltage value via a resistor.

The rectifier circuit 1133 performs full-wave rectification on the output voltage of the current-voltage conversion circuit 1132 using a diode or the like. The rectifier circuit 1133 can halve the monitored voltage range when the voltage is not rectified. When the input voltage is digitized, the resolution of the A / D conversion value can be increased, and the current value is converted to an absolute value.

The arithmetic unit 2010 in FIG. 2 stores a program for determining an operation factor in a storage area. When the program is executed, the voltage value output from the rectifier circuit 1133 is constantly monitored, The magnitude of the current value is detected.

The arithmetic unit 2010 is configured by a microcomputer, and includes an A / D conversion unit 20101, an arithmetic circuit 20102, a register unit 20103, and a determination output unit 20104 in a part thereof.

The A / D converter 20101 divides the output voltage from the current detector 113 by a predetermined time width (sampling time) of several milliseconds or less, and converts the voltage magnitude into an A / D conversion value of a digital signal. To do. As an example, the sampling time is about 0.25 milliseconds.

As an example, if the maximum input voltage of the A / D converter 20101 is 5V and the resolution of digital conversion is 8 bits, the relationship between the voltage input to the A / D converter 20101 and the output is 0 when 0V. When 2.5V is 127, when 5V is 255. Here, when the current-voltage conversion unit 1132 is adjusted so that the 1-bit current value at the time of A / D conversion corresponds to 1 A, the performance of the A / D conversion unit 20101 is a measurement of a current waveform from 0 A to +255 A. Is possible. If the current-voltage conversion unit 1132 is adjusted so that the 1-bit current value corresponds to 2A, the A / D conversion unit 20101 can measure current waveforms from 0A to + 510A. In addition, in order to detect the current value more accurately, use two current transformers for small current and one for large current, and use a total of two dedicated A / D converters. Thus, it may be provided so that a change in the magnitude of the current value during normal use and a change in the magnitude of the overcurrent or the short-circuit current can be detected.

The calculation unit 20102 performs numerical calculation processing on the current magnitude data and the current fluctuation amount based on the A / D conversion value obtained by the A / D conversion unit 20101, and causes the register unit 20103 to perform the current fluctuation amount. Store the data. Also, the current magnitude data and current fluctuation data stored in the register unit 20103 are read, and the presence / absence of overcurrent and short-circuit current is determined by the program based on the current magnitude data. At the same time, the presence / absence of the tracking short-circuit current is determined based on the current fluctuation data.

The register unit 20103 stores current magnitude data for a predetermined time for each unit time. In this embodiment, the unit time is set to 10 ms, and the maximum current magnitude data is acquired during that time, and the maximum current magnitude data for 100 ms, that is, the ten maximum current magnitudes are stored. Accumulate current magnitude data for the latest 100 ms (about 5 peaks at commercial frequency). Then, an average value is calculated for the current magnitude data for 100 ms, and the average value is treated as current value data in the latest electric circuit.

When the circuit breaker is activated, the program obtains current value data in the latest electric circuit from the register unit 20103, and distinguishes whether the operation is due to overcurrent or short-circuit current depending on the magnitude. I do. For example, when the rated current of the circuit breaker is 40 A, the operation up to 320 A, which is eight times the rated current, is determined as an operation in the overcurrent region. If the current value is larger than that, that is, a current value larger than 320 A, the operation is determined as an operation in the short-circuit current region. The overcurrent area or short-circuit current area due to the difference in the rated current may be a fixed processing type (a form using a plurality of programs) that makes a judgment based on a predetermined rated current. A variable processing type (in which one program is used) may be provided in which setting means is provided and the setting value of the rated current is determined to be variable.

A tripping mechanism using a thermo-electromagnetic bimetal is often used as a tripping mechanism for a circuit breaker. The amount of thermal deformation (deflection) of the bimetal depends on the amount of overcurrent. Changes. That is, the larger the overcurrent, the greater the amount of thermal deformation of the bimetal. For this reason, depending on the magnitude of the overcurrent, there is a case where the trip mechanism is not reset and cannot be turned on even if the circuit breaker is operated immediately after the circuit breaker is operated.

In such a case, in order to perform the reclosing operation reliably, the overcurrent-operation time correspondence data 2016 that adjusts the time until the reclosing operation is performed according to the magnitude of the overcurrent is provided as the reclosing control unit. 201. When the arithmetic circuit 20102 in the arithmetic unit 2010 determines that an overcurrent or a short-circuit current has occurred, if the reclosing operation selection unit 2012 is set to perform an operation, the current-operation time correspondence data 2016 is referred to. The optimum time until the reclosing operation is selected according to the magnitude of the current, and the reclosing operation is performed after waiting for a predetermined operation time until the reclosing operation.

Since the flowing current and the amount of deflection of the bimetal are proportional to the square of the current, the current-operation time correspondence data 2016 seems to have a longer operation time until the reclosing in proportion to the square of the magnitude of the overcurrent. It is a defined database. In this embodiment, 5 seconds for overcurrent up to 200% of the rated current, 20 seconds for overcurrent up to 400%, 50 seconds for overcurrent up to 600%, up to 800%. The reclosing time is automatically set as a time distribution with a self-propagation of 90 seconds for the overcurrent of 90 seconds and 180 seconds for the short-circuit current longer than that.

It should be noted that a function for selecting whether or not to read the overcurrent-operation time correspondence data 2016 is provided, and a function for setting the reclosing time to be short regardless of the magnitude of the current is provided. Also good.

Next, detection of the tracking short-circuit current will be described in detail.

The arithmetic circuit 20102 performs numerical arithmetic processing on the current fluctuation amount based on the A / D conversion value obtained by the A / D conversion unit 20101, and causes the register unit 20103 to store the current fluctuation amount data.
Here, the current fluctuation amount is obtained by extracting the current magnitude for each unit time divided into a plurality of predetermined times and calculating the change between the current current magnitude and the current magnitude immediately before. This is a value obtained by converting the obtained value into an absolute value. In this embodiment, the predetermined time is set to about 0.2 seconds (210 ms), and the unit time is set to about 30 ms. In this case, seven pieces of current fluctuation amount data in a predetermined time can be acquired, and the arithmetic circuit 20102 stores the current fluctuation amount data in the register unit in chronological order.

Each time a new current fluctuation amount value is output from the arithmetic circuit 20102, the register unit 20103 excludes the oldest current fluctuation amount value, and simultaneously calculates and obtains the newest current fluctuation amount value. Thus, a plurality of current fluctuation values within a new predetermined time are always stored in chronological order. Further, in order to increase the determination accuracy, it is preferable to provide seven or more always new current fluctuation values to be stored. It is preferable that a possible number can be stored in accordance with the storage capacity of the register unit 20103 and in accordance with the time taken for the determination.

When the arithmetic circuit 20102 determines various operating factors, the arithmetic circuit 20102 outputs a signal to the determination output circuit 20104. The determination output circuit 20104 sends a signal for each operating factor to the operating factor display unit 2011 to display the operating factor. In addition to the display, a signal for increasing the count is sent to the reclosing operation frequency display section according to the operation factor. Note that the reclosing operation transmits a drive signal to the relay 2020 when the operation is set based on the setting of “activate / do not perform” set by the reclosed operation selection means 2012. The drive motor 2021 is driven by driving the relay.

If it is determined that the tracking short-circuit current has occurred, the calculation unit 2010 outputs a trip signal to the trip mechanism, drives the trip mechanism, opens the circuit breaker, and starts from the tracking short-circuit current. Protects electrical circuits and load equipment.

For the data for each sampling time sent from the A / D converter 20101, the arithmetic circuit 20102 extracts the peak current value for each unit time (every 30 ms) and compares it with the peak current value extracted for the previous unit time. The difference is sent to the register unit 20103 as the magnitude of current change (current fluctuation amount). The register unit 20103 stores the magnitude of the current change per unit time as current fluctuation data for a predetermined time, and when the data is newly sent from the arithmetic circuit 20102, the oldest data is discarded, Get the latest data. The predetermined time is about 0.2 seconds. In addition, it is convenient to select the unit time to be about half the time of commercial AC.

The arithmetic circuit 20102 sends the latest data to the register unit 20103, and at the same time fetches data of a magnitude of current change for a predetermined time from the register unit 20103, and calculates the frequency (number) of data in a predetermined range from each data. To do. For example, FIG. 4 shows the magnitude of current change (current fluctuation amount) within a predetermined time in a frequency distribution, and shows a case where a tracking short-circuit current is generated.

FIG. 6 shows the frequency distribution of the magnitude of current change (current fluctuation amount) corresponding to FIG. 2 when no tracking short-circuit current is generated and the current flowing through the electric circuit is due to the use of home appliances. Is the situation. It can be seen that the magnitude of the current fluctuation amount is concentrated in the range of 0 to 4A. On the other hand, FIG. 2 shows that the current fluctuation amount is widely distributed unlike the distribution of home appliances, and the current fluctuation amount appears in a large amount in the range of 5 to 30A. Therefore, paying attention to the portion where the current fluctuation amount is 5 to 30 A, it is determined whether the frequency of the data included in the range exceeds the predetermined frequency within a predetermined time and the occurrence of the tracking short-circuit current is generated. Determine. Even if the magnitude of the current that flows is almost the same due to tracking short-circuiting and that due to the use of home appliances and cannot be distinguished, it is accurately determined whether the current is due to the use of home appliances or due to tracking short-circuiting it can.

This will be described in more detail with reference to FIGS. FIG. 6 is a conceptual diagram of a predetermined time as a unit time A (i), an extracted current magnitude IPA (i) per unit time, and a current change magnitude Delta IPA (i).
The predetermined time is divided into unit times A (i) (i = 1 to n) (n is a positive integer). IPA (i) is a current value extracted by the arithmetic circuit 20102 within the unit time A (i) upon receiving data transmission at every sampling time from the A / D conversion unit 20101 in FIG. 2, and in this example, Although the peak current value within the unit time A (i) is used, an average value within the unit time A (i) may be used. Delta IPA (i) is represented by the difference between IPA (i) and IPA (i-1) as the difference between the magnitude of current extracted for each unit time and the magnitude of current extracted for the previous unit time. .

In the conceptual diagram of FIG. 6, the register unit 20103 stores n pieces of delta IPA (1) to delta IPA (n) and data of IPA (n). In the initial state, each stored data value is zero.

Next, the arithmetic circuit 20102 that has received data transmission from the A / D conversion unit 20101 every sampling time extracts the peak current value IPA (n + 1) within the unit time A (n + 1), and at the same time, extracts one from the register unit 20103. The previous extracted current value (peak current value) IPA (n) is received, delta IPA (n + 1) = IPA (n + 1) −IPA (n) is calculated, and delta IPA (n + 1) is newly sent to the register unit 20103. . However, when the delta IPA (n + 1) becomes negative, it is replaced with a positive value and transmitted.

Before sending the delta IPA (n + 1) to the register unit 20103, the register unit 20103 stores the current fluctuation amounts delta IPA (1) to delta IPA (n) per unit time A (i) as shown in FIG. n data is stored, but when data transmission of a new current fluctuation amount delta IPA (n + 1) is received from the arithmetic circuit 20102, the oldest data delta IPA (1) is discarded and delta IPA (2 ) As delta IPA (1), delta IPA (3) as delta IPA (2)... Delta IPA (n + 1) as delta IPA (n), N current fluctuation amount data delta IPA (1) to delta IPA (n) received, and delta IPA (i) is not less than 5A and less than 30A And power by summing over data number, its frequency is in the case where n × 0.7 or more, and sends a determination signal that is a tracking circuit current in the decision output unit 20104. The unit time is about 3 half-waves of alternating current.

According to the tracking short-circuit current detection method described above, it is possible to determine whether or not the tracking short-circuit current is generated at a data frequency in which the magnitude of the current change is within a predetermined range.

In addition, in order to determine the occurrence of the tracking short-circuit current more accurately, in addition to the determination of the frequency where the magnitude of the current change is in the range of 5 to 30A, the magnitude of the current change is further in the range of 11A to 30A. A condition that whether or not a certain frequency is n × 0.4 or more may be added so that it is determined that a tracking short circuit has occurred when both conditions are satisfied. In this way, it is possible to further improve the determination accuracy of the current due to the use of home appliances and the current due to the tracking short circuit.

Further, FIG. 8 shows an explanatory diagram for increasing the sampling frequency of the A / D conversion unit 20101 and performing the determination with high accuracy. In this example, the unit time A (i) is further divided into m times (m is a positive integer) and divided into Ta (i, 1) to Ta (i, m) times. Ta (i, j) is approximately half the time of the frequency of commercial AC power. Since the period differs between 50 Hz and 60 Hz depending on the region, the middle is set to about 9 ms.

In FIG. 8, IPT (i, j) is a peak current value at the division time Ta (i, j), and delta IPT (i, j) = IPT (i, j) −IPT (i, j−1). is there. The arithmetic circuit 20102 to which data is sent from the A / D conversion unit 20101 at each sampling time extracts the peak current value IPT (i, j) within the divided time, and the previous IPT (i , J−1) and delta IPT (i, j) = IPT (i, j) −IPT (i, j−1) are calculated. If the delta IPT (i, j) becomes negative, it is replaced with a positive value.

In parallel with the extraction of IPA (i) for each unit time A (i), the arithmetic circuit 20102 divides the unit time A (i) into m times Ta (i, 1) to Ta ( For i, m), the delta IPT (i, j) described above is calculated, and if the calculated delta IPT (i, j) is equal to or greater than a certain value (in this embodiment, it is set to 5A), The calculation of the next delta IPT (i, j) is entered, and when the next delta IPT (i, j) is less than a certain value, all the processes are initialized, and the determination process is performed again. Is provided.

That is, if the delta IPT (i, 2) to the delta IPT (i, m) in the unit time A (i) are all equal to or greater than a certain value, the processing is continued and the IPA (in the unit time A (i) ( i) is extracted, and the difference from the adjacent IPA (i-1) is extracted and extracted as the magnitude of the current change in the register unit 20103. Otherwise, the data in the register unit 20103 is also initialized. Therefore, in order for the arithmetic circuit 20102 to finally output the determination that the flowing current is a tracking short circuit to the determination output unit 20104 in FIG. 2, the unit times A (1) to A (n) within a predetermined time ) In all cases, the condition that the delta IPT (i, 2) to the delta IPT (i, m) described in FIG. 8 are equal to or larger than a certain value and the processing is continued is required, and the unit time A (i ) To A (n) current variation When the magnitude of exceeds yet predetermined frequency is in the predetermined range, or it is necessary condition that if it exceeds more is in the predetermined range and yet plurality of predetermined frequency for each predetermined range. In tracking short-circuit, the delta IPT (i, j) often continues at a certain amount or more, and in this example, it becomes possible to more accurately determine whether the current flowing in the electric circuit is a tracking short-circuit current, It can be expected that there will be no malfunction.

Next, regarding the method of determining the operating factor, of the operating factors, the operation due to leakage current and the operation due to lightning surge current will be described.

Regarding the occurrence of the leakage current, the operating factor can be determined by receiving the output signal from the leakage current detection means 112 provided in the circuit breaker by the arithmetic unit 2010. However, as shown in FIG. 9, in the configuration diagram of the 400 V distribution, the varistor 90 is usually provided in the transformer portion arranged on the customer side. When a lightning surge current is generated, the varistor 90 is discharged to the ground, so that the lightning surge current is transferred from the power supply side connection terminal portion 102a of the circuit breaker 100 to the load side connection terminal portion. 103a, flows to the ground through the varistor 90, and an unbalanced current (unbalance) is generated in the current passing through the zero-phase current transformer (ZCT) of the leakage detecting means 112 provided in the circuit breaker 100. The circuit breaker operates in the same way as when current flows.

The connection in the distribution line of the circuit breaker 1 with a reclosing function of this invention is demonstrated easily. The circuit breaker 1 with a reclosing function according to the present invention has a 400V distribution line 92 that is not easily affected by a voltage drop even when a wiring length used in a mountainous area becomes long, a high voltage distribution line 91 (6600V) and a low voltage distribution line. It is used between the lines 93 (100 / 200V).

In order to step down the voltage of 6600V distributed in the high-voltage distribution line 91 to the 400V distribution line 92 that distributes the voltage at 400V, the first transformer 911 (6600 / 200V) is connected to the column branched from the high-voltage distribution line 91; A second transformer 912 (6600 / 200V) is provided. The power sources of the first transformer 911 and the second transformer 912 are provided in parallel to the high voltage distribution line 91. On the load side, the first transformer and the second transformer are connected in series, and the total output voltage is 400V. By using two transformers, a small transformer can be used, and installation on a pillar is simplified.

In the 400V distribution line 92, the circuit breaker with a reclosing function of the present invention is installed on the line. In installation, the electric wire on the power supply side of the electric circuit is drawn into the inlet hole of the casing, and the electric wire on the load side is inserted into the outlet hole to connect to the power supply side and load side connection terminal portions of the circuit breaker 100. . At this time, in the power supply side connection terminal portion, in order to acquire the control power supply of the reclosing means 200 of the circuit breaker, the power supply side of the transformer 203 is connected so as to be tightened with the electric wire.

The 400V distribution line is laid to the vicinity of the customer, and the voltage is lowered from 400V to 100 / 200V by the transformer near the customer, and the 100 / 200V distribution line 93 is distributed to the customer.

Now, it is necessary to distinguish between the operation due to the leakage current in the circuit and the operation due to the lightning surge current. In this example, the leakage current due to the abnormality in the circuit continues and the lightning surge current is transient. Assumes. For this reason, the arithmetic circuit 20102 is driven to perform the reclosing operation once when operated by the input signal from the leakage current detecting means 112, and the leakage current is detected when the circuit breaker is immediately interrupted by the reclosing operation. A program should be provided so that it is determined that a lightning surge current has occurred unless it is immediately shut off. When the reclosing operation selection means 2012 provided in the reclosing control unit 201 is selected to “do not perform the reclosing operation”, the trip mechanism unit is determined again after determining that a lightning surge current has occurred. A trip signal is sent out to make the circuit breaker open, and the subsequent operation is stopped.

As described above, in the operation of the circuit breaker, it is possible to determine the operation due to overcurrent, the operation due to the short circuit current, the operation due to the tracking short circuit current, the operation due to the leakage current, and the operation due to the lightning surge current.

For lightning surge current discrimination, a varistor is installed in the circuit breaker housing with a reclosing function to detect and acquire the current flowing through the varistor. A determination unit may be provided. In this way, it is possible to determine the occurrence of lightning surge current and leakage current without performing reclosing operation to distinguish between leakage current and lightning surge current.

Next, the operation of the mechanical part of the circuit breaker with a reclosing function will be described.
In FIG. 2, the reclosing control unit 201 is supplied with AC power (AC 100 V) via a control power switch 204 that is provided on the load side of the transformer 203 and turns on / off the power supply to the control unit 201. The AC power supplied from the control power switch 204 is input to the control power supply unit 205 and transformed into a DC voltage (DC12V) used in the control circuit by the control power supply unit 205.
The control power supply unit 205 supplies a reclosing control unit 201, a reclosing mechanism unit 202, and a relay 2020 power supply.

FIG. 10 is a view of the reclosing mechanism 202 as seen from the side. The reclosing mechanism 202 includes a driving motor 2021, a rotating plate 2022 fixed to the driving motor 2021, a connecting arm 2023 having one end connected to the rotating plate 2022 via a connecting portion 20221, and the connection The arm 2025 is connected to the other end of the arm 2023 via a rotary bearing 2024, and an action unit 315 fixed to the arm 2025 and acting on the operation handle 101 is configured.

The driving motor 2021 is connected to the relay 2020. When the driving signal for performing the reclosing operation is transmitted from the arithmetic unit 2010, the relay 2020 is operated, and power is supplied from the control power source unit 205. Drive.

Next, the operation of the circuit breaker with a reclosing function will be described.
Normally, the reclosing mechanism 202 is in a positional relationship with the operation handle 101 of the circuit breaker 100 as shown in FIG. 10A (standby state). The operation handle 101 of the circuit breaker 100 is in the on position.

Now, when the circuit breaker 100 operates due to an abnormal current (overcurrent or short-circuit current), tracking short-circuit current, leakage current or lightning surge that flows through the circuit, The fact that the contact of the micro switch provided in the operating state detecting means that is interlocked is closed and closed in a circuit is input to the calculation unit 2010 of the reclose control unit 201 through the signal line. At this time, the operation handle 101 of the circuit breaker 100 is in the cut position, that is, the positional relationship as shown in FIG.

Receiving the input, the arithmetic circuit 20102 performs determination processing based on the programmed contents, and sends a drive signal for performing the reclosing operation to the relay 2020.

Upon receiving the drive signal, the relay 2020 closes the relay contact, and supplies the power supplied from the control power supply unit 205 to the drive motor 2021 of the reclosing mechanism unit 202.

The driving motor 2021 that has received the power supply starts rotating (FIG. 11). As a result, the rotating plate 2022 fixed to the driving motor 2021 also starts to rotate in the direction of the arrow in the figure, and the connecting arm 2023 connected via the connecting portion 20221 draws an arc in the left direction in the figure. Extruded.

In conjunction with the operation of the connecting arm 2023, the arm 2025 moves through an arm rotation bearing 2024 provided at one end so as to draw a circular arc in the left direction in the figure around the arm rotation center 20251. The handle operation unit 2026 provided on the arm also moves in the left direction in the figure.

Along with the movement of the arm 2025, the handle operating unit 2026 pushes and moves the operation handle 101 in the direction of closing the circuit breaker 100, so that the circuit breaker 100 is turned on.

When the drive motor 2021 continues to rotate, the rotation of the rotating plate 2022 causes the connecting portion 20221 to move so as to draw a downward arc locus in the direction of the arrow indicated by the dotted line in FIG. The arm 2025 and the handle action unit 2026 operate in the right direction (the direction away from the operation handle 101). In this case, the operation handle 101 remains stopped at the closed position (entering position) because the operation is performed without interference that does not interfere with the operation handle 101.

When the rotating plate 2022 rotates once and rotates to the original position, the calculation unit stops sending the drive signal and enters the standby state again.

That is, when the operation handle 101 of the circuit breaker 20 is in the closed position (on position), even if the reclosing means of the circuit breaker performs a series of operations, the operation of the circuit breaker 20 is not affected. Only when the handle 101 is in the cut position, the operation handle is operated.

It should be noted that the present invention is not limited to the embodiment, and can be freely improved and modified as necessary without departing from the gist of the invention. For example, the AC voltage of the circuit (AC400V) When the voltage is stepped down in the housing, it may be configured using a transformer that directly converts the direct current voltage (DC12V) used for the operation of the control circuit. With this configuration, it is not necessary to transform AC 100 V to DC 12 V in the control power supply unit 205, the number of transformers in the housing can be reduced by one, and the cost of the circuit breaker with a reclosing function can be reduced. Can be done.

In addition, in the operation unit 2010, when the circuit breaker 100 is immediately shut off when the circuit breaker 100 is reclosed, when a protection operation is performed to stop the subsequent reclosing operation, a circuit breaker with a reclosing function is installed. It is necessary to reset to enable the reclosing operation to be performed again by releasing the protective action of the circuit breaker with the reclosing function, and the reset part that performs this reset operation is located outside the housing. By installing a reset part in the middle part of the pillar so that it can be easily operated from the upper part of the pillar where the circuit breaker with drawer and normal reclosing function is installed, it is possible to avoid adverse environments such as rain and snow. Even inside, a circuit breaker with a reclosing function can be provided so that personnel who go to the site can easily perform a reset operation.

Further, the circuit breaker reclosing means 200 is a unit that completes the arrangement of the circuit breaker reclosing means 200 and the power supply acquisition within the casing, so that the circuit breaker may be deteriorated due to lightning surge or deterioration over time. If the reclosing means breaks down, the unit can be replaced and replaced, so that there is no need for wiring connection work on the pole transformer or replacement of the housing itself, and the reclosing function can be easily achieved. Restoration can be performed.

Since the circuit breaker with a reclosing function of the present invention can accurately determine the operation factor of the circuit breaker and is provided with a selection means for performing the reclosing operation for each operation factor, However, when the circuit breaker operates by separately inputting a signal to be output as a result of the operation selection means to the communication device, the usage can be expanded to notify the remote device that the circuit breaker has been operated. It is a possibility.

It is an internal structure figure of the circuit breaker with a reclosing function which concerns on embodiment of this invention. It is a block block diagram of the circuit breaker with the same reclosing function. It is a block block diagram of an electric current detection means. Distribution of current fluctuation amount under the condition that tracking short-circuit current is generated. Distribution of current fluctuations under the condition that no tracking short-circuit current occurs. The conceptual diagram which showed the detection method of tracking short circuit current. The conceptual diagram which showed the detection method of tracking short circuit current. The conceptual diagram which showed the detection method of tracking short circuit current. The connection wiring diagram of the circuit breaker with a reclosing function in a 400V electric circuit. The figure which showed the reclosing mechanism part. The figure which showed the reclosing mechanism part. It is the figure which showed the prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Circuit breaker with a reclosing function 2 Power supply side electric wire 21 Inlet hole 3 Load side electric wire 31 Outlet hole 100 Circuit breaker 101 Operation handle 102 Power supply side connection terminal part 103 Load side connection terminal part 111 Operation state detection means

112 Current leakage detection means 113 Current detection means 1131 Current transformer 1132 Current-voltage conversion means 1133 Rectifier circuit 200 Reclosing means 201 Reclosing control section 202 Reclosing mechanism section 203 Transformer section 204 Control power switch 205 Control power supply section 2010 Calculation section 2011 Operation factor display unit 2012 Reclosing operation selection means 2013 Reclosing operation frequency display unit 2014 Lock display unit 2015 Reset switch 2016 Overcurrent-operation time correspondence data 20101 A / D conversion unit 20102 Arithmetic circuit 20103 Register unit 20104 Determination output unit 202 Reclosing mechanism 2021 Driving motor 2022 Rotating plate 2023 Connection arm 2024 Rotating bearing 2026 Handle action unit 2025 Arm 20251 Rotation center 20221 Connection unit 91 High voltage distribution line 911 First transformer 912 First Two transformers 92 400V distribution line 921 400/100 / 200V transformer 93 100 / 200V distribution line

Claims (1)

There is an operation handle that is interposed in the electric circuit and operates to turn on and off the power to the load side electric circuit. When an abnormal current in the electric circuit is detected, an opening / closing mechanism provided inside and a tripping mechanism that acts on the opening / closing mechanism are provided. A circuit breaker that shuts off the power supply to the electric circuit by being activated, and a circuit breaker that automatically turns off when the power supply to the load side electric circuit is stopped by the cutting operation of the circuit breaker. A circuit breaker with a reclosing function comprising a reclosing control unit having a reclosing control unit and a reclosing mechanism unit that act on the operation handle of the circuit and to turn on the circuit breaker.
In the reclosing controller,
An operation factor determining means for determining a factor causing the circuit breaker to be turned off and outputting a driving signal for reclosing the operation circuit of the circuit breaker by inserting the operation handle of the circuit breaker into the reclosing mechanism;
Provided as means for determining the factor,
Overcurrent detection means for detecting overcurrent in the electric circuit;
A short-circuit current detecting means for detecting a short-circuit current in the electric circuit;
A leakage current detecting means for detecting a leakage current in the electric circuit;
Lightning surge current detection means for detecting lightning surge current in the electric circuit;
Tracking short-circuit current detection means for detecting the tracking short-circuit current;
Connected to the operating factor determining means ,
The operation factor is listed and an LED lamp is provided for each of the operation factors, and an operation factor display unit that can distinguish and visually recognize the factor that has operated most recently by lighting and displaying the factor that has operated most recently,
A reclosing operation selecting means provided next to the operation factor display section for selectively selecting whether or not to perform the reclosing operation for each operation factor ;
A reclosing operation frequency display section provided next to the reclosing operation selection means and displaying the number of reclosing operations for each operation factor;
Further, in the reclosing control unit,
Connected to the operating factor discrimination means, the magnitude of the overcurrent at the time of overcurrent detection is compared with the rated current of the circuit breaker, and based on the ratio between the magnitude of the overcurrent and the rated current, A circuit breaker with a reclosing function, characterized in that an automatic reclosing time setting unit is provided for changing a time from the operation to the output of a drive signal for reclosing.