JP2012198124A - Power distribution device and voltage measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power distribution device and a voltage measurement method that can simplify operation to measure a voltage.SOLUTION: The power distribution device includes a transformer 1 for instrument and a circuit part 4 having at least one voltage measurement circuit 41 connected between secondary-side lines 2, 2 of the transformer 1 for instrument. The voltage measurement circuit 41 includes a resistance 411 which has a predetermined resistance value, and a measurement part 412 which is so arranged that a current value can be measured by a clamp meter, and formed by insulating and covering a conductor. The measurement part 412 measures the current value, and calculates a voltage value based upon the measured current value and the resistance value of the resistance 411.

Description

  The present invention relates to a power distribution device comprising an instrument transformer and at least one voltage measurement circuit connected between secondary wires of the instrument transformer, and a voltage for measuring a voltage of a predetermined portion of the power distribution device. It relates to a measurement method.

  Conventionally, as a device for measuring a line voltage (interphase voltage) which is a voltage between each line of a three-phase three-wire system at a high voltage or extra high voltage, and a phase voltage (a ground voltage) which is a voltage between each line and the ground, Voltmeters are known. Such a voltmeter is connected between the secondary side wires of the instrument transformer by connecting to the test plug inserted into the test terminal of the switchboard via the voltage test terminal. Inter-voltage and phase voltage can be measured (for example, Patent Document 1).

JP 2007-147372 A

  By the way, in order to prevent the instrument transformer from being burned out or to keep the relay energized, use a tester to insert the test plug into the test terminal before inserting the test plug into the test terminal. It is necessary to check the short circuit condition. Therefore, there has been a problem that the operation of measuring the voltage becomes a very complicated operation.

  Therefore, in view of such circumstances, an object of the present invention is to provide a power distribution device and a voltage measurement method capable of simplifying the work of measuring a voltage.

  The power distribution device according to the present invention is a power distribution device including a meter transformer and a circuit unit having at least one voltage measurement circuit connected between the secondary side wires of the meter transformer. And a measuring part which is arranged so that a current value can be measured by a clamp meter and is formed by insulating a conductor.

  According to the power distribution device according to the present invention, the voltage measuring circuit connected between the secondary wires of the instrument transformer is provided with a resistor having a predetermined resistance value. As a result, a current corresponding to the voltage flows through the voltage measurement circuit. Therefore, by measuring the current value with a measuring unit arranged so that the current value can be measured by a clamp meter (overhead ammeter). The voltage value can be calculated. Moreover, since the measurement part is formed by insulatingly covering the conductor, it is possible to prevent an electric shock when measuring with a clamp meter.

  In the present invention, the “instrument transformer” includes not only an instrument transformer called VT (or PT) but also a grounded instrument transformer called EVT (or GVT or GPT). Is also included. Further, in the present invention, “between the secondary side lines of the instrument transformer” includes not only between the lines connected to the secondary terminal of the VT, but also between the lines connected to the secondary terminal of the EVT, Also included is the line connected to the tertiary terminal.

  Further, in the power distribution device according to the present invention, the relay connected between the secondary side wires of the instrument transformer, the circuit unit and the relay so as to be connected in parallel with the circuit unit with respect to the instrument transformer. While maintaining the connection, it is equipped with a power failure switching means that can switch between the energized state that applies the voltage of the instrument transformer to the relay and the power failure state that interrupts the energization, and the circuit unit applies the test voltage to the relay You may provide the test terminal part for connecting with the testing apparatus to do.

  According to the power distribution device having such a configuration, the relay is connected between the secondary lines of the instrument transformer. And since the power failure switching means can switch between the energized state where the voltage of the instrument transformer is applied to the relay and the power outage state where the current is interrupted, the repair and replacement of the relay can be performed by setting the relay to a power failure state. Etc. can be easily performed.

  Furthermore, the circuit unit and the relay are connected in parallel to the instrument transformer, and the circuit unit is provided with a test terminal unit for connection to a test apparatus. Then, the power failure switching means maintains the connection between the circuit portion and the relay, and after switching the relay to the power failure state, the test device applies a test voltage to the relay via the test terminal portion, whereby the relay Can be tested.

  Further, in the power distribution device according to the present invention, the power distribution device includes a power distribution board having a housing that accommodates the test terminal portion, the housing includes an opening that exposes the test terminal portion, and the power distribution board is in a state of closing the opening. A cover portion that is displaceable with respect to the housing in order to switch between the open state and a preventing means for preventing the cover portion from switching from a state of closing the opening to a state of opening when the relay is energized. May be.

  According to the power distribution device having such a configuration, the housing that accommodates the test terminal portion is provided with the opening, and the cover portion is displaced with respect to the housing to close the opening. The state to be opened can be switched. Therefore, a test apparatus can be connected to a test terminal part by opening an opening part with a cover part and exposing a test terminal part through an opening part.

  Furthermore, the prevention means prevents the cover portion from switching from a state of closing the opening to a state of opening when the relay is energized. Thereby, since it can prevent that an opening part is open | released in the energized state of a relay, ie, the state which is supplying with electricity to a test terminal part, it can prevent making an electric shock in a test terminal part.

  The voltage measurement method according to the present invention is characterized in that a current value is measured by the measurement unit using a clamp meter, and a voltage value is calculated based on the measured current value and the resistance value of the resistor. To do.

  According to such a voltage measuring method, the voltage measuring circuit connected between the secondary wires of the instrument transformer is provided with a resistor having a predetermined resistance value. Current will flow. Therefore, the current value is measured by the measuring unit using the clamp meter, and the voltage value can be calculated based on the measured current value and the resistance value of the resistor.

  As described above, according to the power distribution device and the voltage measurement method according to the present invention, there is an excellent effect that the work of measuring the voltage can be simplified.

The expansion | deployment connection diagram of the power distribution apparatus which concerns on one Embodiment of this invention is shown. The expanded connection figure in the circuit part of the power distribution apparatus which concerns on the embodiment is shown. It is an expanded connection figure in the circuit part of the power distribution apparatus concerning the embodiment, (a) shows the state where a line voltage is measured, and (b) shows the state where a phase voltage is measured. It is a power distribution apparatus which concerns on the embodiment, Comprising: (a) is a whole front view, (b) shows the enlarged view of A area | region. It is an enlarged view of the B area of Drawing 4 of a power distribution device concerning the embodiment, (a) shows the state where a cover part closes an opening, and (b) shows the state where a cover opens an opening.

  Hereinafter, an embodiment of a power distribution apparatus according to the present invention will be described with reference to FIGS.

  As shown in FIGS. 1 to 5, the power distribution apparatus according to the present embodiment is connected to the instrument transformer 1 whose primary side is connected to the bus, and the secondary side lines 2 of the instrument transformer 1. And a plurality of relays 3. And a power distribution apparatus is provided with the circuit part 4 connected to the secondary side wire | line 2, ... of the transformer 1 so that it may connect in parallel with the relay 3 with respect to the transformer 1 for instruments.

  In addition, the power distribution device can switch between an energized state in which the voltage of the instrument transformer 1 is applied to each relay 3 and a power outage state in which the energization is interrupted while maintaining the connection between each relay 3 and the circuit unit 4. A power failure switching means 5 is provided. Furthermore, the power distribution apparatus includes a power distribution board 6 that accommodates the instrument transformer 1 and the like.

  In this embodiment, the instrument transformer 1 is a grounded instrument transformer (EVT) that is a star-star open delta connection. And in such an instrument transformer 1, between each phase of the secondary terminal (between uv, vw, wu), a line voltage, between each phase of the secondary terminal and the ground phase (between oo, vo, wo, Phase voltage between the terminals of the open delta of the tertiary terminal (between af), and the zero phase voltage can be taken out.

  Among the plurality of relays 3,... In this embodiment, between the secondary side lines 2 and 2 of each phase connected between the secondary terminals of the instrument transformer 1 (between uv, vw, and wu). In addition, an undervoltage relay is connected to each of the secondary side wires 2 and 2 (between af) connected to the open delta terminal of the tertiary terminal in the instrument transformer 1. It is connected. Each relay 3 is attached to the switchboard 6.

  The circuit unit 4 includes a plurality of voltage measurement circuits 41 connected between the secondary side lines 2 and 2 of the instrument transformer 1 and a connection switching means 42 for switching the connection of each voltage measurement circuit 41. Further, the circuit unit 4 includes a plurality of test terminal units 43,... For connection to a test apparatus (not shown and numbered) that applies a test voltage to each relay 3.

  Each voltage measurement circuit 41 includes a resistor 411 having a predetermined resistance value and a measurement unit 412 whose current value is measured by a clamp meter (not shown or numbered). Each voltage measuring circuit 41 is configured to be able to change between the connected secondary side lines 2 and 2, that is, between the secondary side lines 2 and 2 that are objects to be measured (measuring objects) by the connection switching means 42. Has been.

  In the present embodiment, each voltage measurement circuit 41 is connected to the open state (see FIG. 2) opened from the secondary side wires 2 and 2 of the instrument transformer 1 by the connection switching means 42 and each of the instrument transformer 1. Line connection state (see FIG. 3 (a)) connected between the secondary side lines 2 and 2 of the phase (between uv, vw, and wu), 2 of each phase of the instrument transformer 1 and the ground phase It is switched to the phase connection state (refer to FIG. 3B) connected between the secondary lines 2 and 2 (between uo, vo, and wo).

  In FIG. 3, the energized portion is shown by a solid line. Specifically, as shown in FIG. 3A, the secondary side lines 2, 2, and 2 of each phase (u, v, w) are delta-connected. As a result, the voltage measuring circuits 41 are connected to each other, and, as shown in FIG. 3B, the secondary wires 2, 2, and 2 of each phase (u, v, w) are star-connected. By connecting the secondary side wire 2 of the ground phase (o) to the neutral point of the star connection, each voltage measuring circuit 41 is in a phase connection state. Note that the power consumption by the resistor 411 can be prevented by opening each voltage measurement circuit 41.

  Each measuring unit 412 is formed by insulatingly covering a conductor. In the present embodiment, each measurement unit 412 is an insulated wire. Each measurement unit 412 is housed inside the switchboard 6.

  The connection switching means 42 includes a connection switching operation unit 421 operated by an operator, and each voltage measurement circuit 41 in an open state, a line connection state, and a phase connection state as the connection switching operation unit 421 is operated. And a connection changeover switch unit 422. The connection switching operation unit 421 is attached to the switchboard 6.

  In the present embodiment, the voltage measurement circuit 41 is opened by rotating the connection switching operation unit 421 so that the mark unit 421a of the connection switching operation unit 421 is set to the “disconnected” position. By aligning the position 421a with the “line-to-line” position, each voltage measurement circuit 41 is in the line-to-line connection state. It becomes.

  Each test terminal portion 43 is formed by exposing a conductor. In the present embodiment, each test terminal portion 43 is a bare wire. Each test terminal portion 43 is accommodated inside the switchboard 6. Note that a terminal of a test apparatus is connected to the test terminal unit 43 in order to test whether or not each relay 3 operates at a predetermined voltage value (set voltage value).

  The power failure switching means 5 is a power failure switching operation unit 51 operated by an operator and a communication device that switches the relays 3, ... between the energized state and the power failure state as the power failure switching operation unit 51 is operated. A power failure changeover switch unit 52. And the power failure switching operation part 51 is attached to the switchboard 6.

  In this embodiment, the power failure switching operation unit 51 is rotated and the mark unit 511 of the power interruption switching operation unit 51 is set to the “energized” position, whereby the relays 3,. By setting to the position of “power failure”, the relays 3,.

  The switchboard 6 includes a housing 61 that accommodates each voltage measurement circuit 41, each test terminal portion 43, and the like. The housing 61 is provided with a first opening 611 that exposes each test terminal portion 43, and A second opening 612 is provided through which each measurement unit 412 is exposed. In addition, the switchboard 6 includes a cover portion 62 that can close the first opening portion 611 and a prevention unit 63 that prevents the first opening portion 611 from being opened when the relay 3 is energized. .

  The first opening 611 exposes each test terminal portion 43 so that the test apparatus can be connected to each test terminal portion 43. And the 1st opening part 611 is arrange | positioned in the vicinity of the power failure switching operation part 51 in order to make the operation | work of the power failure switching operation part 51 and the test | work of the relay 3 smooth. Further, the first opening 611 is disposed on the lower side of the housing 61.

  The second opening 612 exposes each measurement unit 421 so that the current value of each measurement unit 421 can be measured using a clamp meter (not shown and not picked). The second opening 612 is disposed in the vicinity of the connection switching operation unit 421 in order to facilitate the operation of the connection switching operation unit 421 and the current measurement in the measurement unit 412. Further, the second opening 612 is disposed on the lower side of the housing 61.

  The cover 62 is formed in a plate shape and is configured to be displaceable with respect to the housing 61. And the cover part 62 is connected with the power failure switching operation part 51 through the prevention means 63. FIG. Thereby, the cover part 62 is in the state which closes by covering the 1st opening part 611, and the state which opens the 1st opening part 611 in connection with the power failure switching operation part 51 being operated. Can be switched.

  Specifically, since the prevention means 63 connects the power failure switching operation part 51 and the cover part 62, when the mark part 511 of the power interruption switching operation part 51 is set to the position of “energization”, the cover part 62 Is in a state in which the first opening 611 is closed, and when the mark portion 511 of the power failure switching operation unit 51 is set to the position of “power failure”, the cover portion 62 opens the first opening 611. Become. Therefore, the prevention means 63 prevents the cover 62 from switching from a state of closing the first opening 611 to a state of opening when the relays 3,.

  As described above, according to the power distribution device according to the present embodiment, each voltage measurement circuit 41 connected between the secondary wires 2 and 2 of the instrument transformer 1 is provided with the resistor 411 having a predetermined resistance value. Therefore, a current corresponding to the voltage flows through each voltage measurement circuit 41. The measuring unit 412 is arranged so that the current value can be measured, and the measuring unit 412 is formed by insulating and covering the conductor, so that the current value of the measuring unit 412 can be measured with a clamp meter without electric shock. It can be measured.

  Thus, based on the current value flowing through the voltage measurement circuit 41 measured by the measurement unit 412 and the resistance value of the resistor 411 of the voltage measurement circuit 41, the voltage value between the secondary lines 2 and 2, for example, the line voltage And the phase voltage can be calculated. Therefore, the work of measuring the voltage can be simplified.

  Moreover, according to the power distribution apparatus which concerns on this embodiment, the relays 3 and ... are connected between the secondary side lines 2 and 2 of the transformer 1 for instruments. And since the power failure switching means 5 can switch between the energized state in which the voltage of the instrument transformer 1 is applied to each relay 3 and the power outage state in which the energization is interrupted, each relay 3 is brought into a power failure state. The relays 3 can be easily repaired and replaced.

  Furthermore, according to the power distribution apparatus according to the present embodiment, the circuit unit 4 and each relay 3 are connected in parallel to the instrument transformer 1, and the circuit unit 4 is connected to the test apparatus. Are provided with test terminal portions 43,. The power failure switching means 5 maintains the connection between the circuit unit 4 and each relay 3 while switching each relay 3 to a power failure state, and then the test apparatus relays the relay 3 via the test terminal portions 43,. An operation test of the relay 3 can be performed by applying a test voltage to the relay 3.

  Further, according to the power distribution device according to the present embodiment, the first opening 611 is provided in the housing 61 that accommodates each test terminal portion 43, and the cover 62 is located with respect to the housing 61. By displacing, the state of closing the first opening 611 and the state of opening can be switched. Therefore, the test device can be connected to each test terminal portion 43 by opening the first opening 611 with the cover portion 62 and exposing each test terminal portion 43 through the first opening 611.

  Furthermore, according to the power distribution apparatus according to the present embodiment, the prevention unit 63 prevents the cover 62 from switching from the state of closing the first opening 611 to the state of opening in the energized state of each relay 3. . Thereby, since it can prevent that the 1st opening part 611 is open | released in the energized state of each relay 3, ie, the state in which each test terminal part 43 is energized, it is made to receive an electric shock in each test terminal part 43. Can be prevented.

  In addition, the power distribution apparatus and the voltage measurement method according to the present invention are not limited to the above-described embodiments, and it is needless to say that various changes can be made without departing from the scope of the present invention. Moreover, it is needless to say that configurations, methods, and the like according to various modifications described below may be arbitrarily selected and employed in the configurations, methods, and the like according to the above-described embodiments.

  For example, in the power distribution device and the voltage measuring method according to the present invention, the clamp meter displays the measured current value, and calculates the voltage value based on the displayed current value and the resistance resistance value ( Method), and by inputting the resistance value of the resistor to the clamp meter, the clamp meter automatically calculates the voltage value based on the measured current value and the input resistance value. A configuration (method) in which the voltage value is displayed may be used.

  Further, in the power distribution device and the voltage measurement method according to the above embodiment, the configuration in which the instrument transformer 1 is a grounded instrument transformer called EVT (or GVT or GPT) has been described. It is not limited to the configuration. For example, the configuration may be such that the instrument transformer is an instrument transformer called VT (or PT).

  Further, in the power distribution device and the voltage measurement method according to the above embodiment, the configuration in which the circuit unit 4 is connected to the secondary side wires 2 connected to the secondary terminal of the instrument transformer 1 has been described. It is not limited to such a configuration. For example, the circuit unit 4 may be configured to be connected to the secondary side wires 2,... Connected to the tertiary terminal of the instrument transformer 1, and is connected to the tertiary terminal of the instrument transformer 1. The structure connected only to the secondary side line 2, ... may be sufficient.

  Moreover, in the power distribution apparatus and voltage measuring method according to the above embodiment, the undervoltage relay 3 is connected between the secondary side wires 2 and 2 of each phase connected to the secondary terminal in the instrument transformer 1. In addition, the configuration in which the ground fault overvoltage relay is connected between the secondary side wires 2 and 2 connected to the open delta terminal of the tertiary terminal in the instrument transformer 1 has been described. I can't. For example, a configuration in which an overvoltage relay or a directional distance relay is connected between the secondary side wires 2 and 2 of each phase connected to the secondary terminal in the instrument transformer 1 may be used. A configuration in which a circuit selection relay or a ground fault sequence interruption relay is connected between the secondary side wires 2 and 2 connected to the terminals may be employed.

  Moreover, in the power distribution apparatus and voltage measuring method according to the above-described embodiment, the connection switching means 42 causes each voltage measurement circuit 41 to be in an open state, a line connection state (a connection state in which line voltage can be measured), and a phase connection state. Although the structure which can be switched to (the connection state in which the phase voltage can be measured) has been described, the present invention is not limited to such a structure. For example, the voltage measurement circuit may be configured to be switchable between an open state and a line connection state, may be configured to be switchable between an open state and a phase connection state, and is always in a line connection state. A configuration or a configuration in which the phases are always connected may be used.

  Moreover, in the power distribution apparatus and voltage measuring method which concern on the said embodiment, although the measurement part 412 demonstrated the structure which is an insulated wire, it is not restricted to such a structure. For example, the measurement unit may be configured such that a conductive bar or plate is covered with an insulating material. In short, the measurement unit may be configured so that the operator does not get an electric shock even if the voltage measurement circuit is measured by the clamp meter when the voltage measurement circuit is energized.

  In the power distribution device and the voltage measurement method according to the above embodiment, the measurement unit 412 is disposed inside the housing 61 and the measurement unit 412 is exposed through the second opening 612 of the housing 61. Therefore, the configuration that can be measured in the clamp meter has been described, but the configuration is not limited thereto. For example, the measurement unit may be arranged outside the housing 61 and arranged so as to be always exposed.

  Further, in the power distribution device and the voltage measurement method according to the above-described embodiment, the configuration in which the second opening 612 that exposes the measurement unit 412 is always open has been described, but the configuration is not limited thereto. For example, the switchboard may include a cover member that can cover the second opening 612 and may be configured to open and close the second opening 612 as necessary.

  Moreover, in the power distribution apparatus and voltage measuring method which concern on the said embodiment, one switchboard 6 is provided, and the transformer 1 for an instrument, the measurement part 412, and the test terminal part 43 are in the common switchboard 6 (the same switchboard 6). Although the structure accommodated was demonstrated, it is not restricted to such a structure. For example, the power distribution device may be provided with a plurality of power distribution panels, and the instrument transformer, the measurement unit 412 and the test terminal unit may be accommodated in different power distribution panels.

  Moreover, in the power distribution apparatus and voltage measurement method according to the above-described embodiment, the configuration in which the cover unit 62 rotates in conjunction with the rotation operation of the power failure switching operation unit 51 has been described, but the configuration is not limited thereto. For example, the power failure switching operation unit is configured to be movable in a straight line (vertical direction, lateral direction) with respect to the housing 61, and the cover unit is linearly linked with the operation of the power failure switching operation unit. It may be configured to move in the shape (vertical direction, horizontal direction).

  Further, in the power distribution device and the voltage measurement method according to the above-described embodiment, the cover 62 is switched between a state in which the first opening 611 is closed and a state in which the first opening 611 is opened, and the first opening 611 is opened. Although the configuration in which the test terminal portion 43 is exposed has been described, the configuration is not limited to such a configuration. For example, the power distribution device is provided with a cylindrical covering member that is inserted into the test terminal portion 43 with respect to a configuration in which the cover portion 62 is not provided and the first opening 611 is always opened. The cover terminal may be displaced (slid) with respect to the test terminal portion 43 so that the test terminal portion 43 is exposed through the first opening 611.

  Moreover, in the power distribution apparatus and the voltage measurement method according to the above-described embodiment, the prevention unit 63 connects the power failure switching operation unit 51 and the cover unit 62 so that the cover unit 62 is not in the energized state. Although the configuration for preventing the first opening 611 from being switched from the closed state to the opened state has been described, the configuration is not limited thereto. For example, the switchboard includes a regulation unit that regulates movement with respect to the casing 61 by locking the cover 62 when the relay 3 is energized, and the regulation unit includes the relay 3 being in a power outage state. In this case, a configuration for releasing the restriction may be used.

  Moreover, in the power distribution apparatus and voltage measuring method which concern on the said embodiment, although the test terminal part 43 demonstrated the structure which is a bare wire, it is not restricted to such a structure. For example, when the terminal of the test apparatus is a Y terminal or a round terminal, the test terminal portion includes a pedestal and a screw that is screwed to the pedestal, and the terminal of the test apparatus is sandwiched between the pedestal and the screw, so-called, The structure provided with a screw-type terminal mechanism may be sufficient.

  DESCRIPTION OF SYMBOLS 1 ... Instrument transformer, 2 ... Secondary side line, 3 ... Relay, 4 ... Circuit part, 5 ... Power failure switching means, 6 ... Distribution board, 41 ... Voltage measurement circuit, 43 ... Test terminal part, 61 ... Housing, 62 ... cover part, 63 ... prevention means, 411 ... resistance, 412 ... measurement part, 611 ... (first) opening

Claims (4)

In a power distribution apparatus comprising an instrument transformer and a circuit unit having at least one voltage measurement circuit connected between secondary lines of the instrument transformer,
The voltage measurement circuit includes a resistor having a predetermined resistance value, and a measurement unit that is arranged so that a current value can be measured by a clamp meter and is formed by insulating a conductor. Maintaining the connection between the relay connected to the secondary line of the instrument transformer and the circuit section and the relay so that the instrument transformer is connected in parallel with the circuit section, the relay is connected to the instrument transformer. A power failure switching means capable of switching between an energized state in which the voltage of the vessel is applied and a power failure state in which the energization is cut off,
The power distribution device according to claim 1, wherein the circuit unit includes a test terminal unit to be connected to a test device that applies a test voltage to the relay. Provided with a switchboard having a housing for accommodating the test terminal portion,
The housing includes an opening that exposes the test terminal portion,
The switchboard changes from a state in which the cover portion closes the opening portion to a state in which the cover portion is closed in the energized state of the cover portion that can be displaced with respect to the housing and the relay in order to switch between the state in which the opening portion is closed and the state in which the opening portion is opened. The power distribution device according to claim 2, further comprising prevention means for preventing switching.   A current value is measured by the measuring unit according to any one of claims 1 to 3 using a clamp meter, and a voltage value is calculated based on the measured current value and a resistance value of a resistor. Voltage measurement method.

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