WO2013030655A1 - Electricity meter - Google Patents

Electricity meter Download PDF

Info

Publication number
WO2013030655A1
WO2013030655A1 PCT/IB2012/001668 IB2012001668W WO2013030655A1 WO 2013030655 A1 WO2013030655 A1 WO 2013030655A1 IB 2012001668 W IB2012001668 W IB 2012001668W WO 2013030655 A1 WO2013030655 A1 WO 2013030655A1
Authority
WO
WIPO (PCT)
Prior art keywords
current
circuit
power
types
burden
Prior art date
Application number
PCT/IB2012/001668
Other languages
French (fr)
Japanese (ja)
Other versions
WO2013030655A4 (en
Inventor
明実 塩川
雄介 宮村
省互 一村
西川　誠
裕 荻野
Original Assignee
パナソニック株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by パナソニック株式会社 filed Critical パナソニック株式会社
Priority to CN201280040798.1A priority Critical patent/CN103748475A/en
Publication of WO2013030655A1 publication Critical patent/WO2013030655A1/en
Publication of WO2013030655A4 publication Critical patent/WO2013030655A4/en

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R21/00—Arrangements for measuring electric power or power factor
    • G01R21/133—Arrangements for measuring electric power or power factor by using digital technique
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
    • G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
    • G01R15/18—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using inductive devices, e.g. transformers

Definitions

  • the present invention current transformers: a power measuring device (CT Current Transformer) to be connected to measure the power of the circuit in such distribution board inside.
  • CT Current Transformer a power measuring device
  • a current transformer is used to expand the measurement range.
  • a power meter is connected to the receiving circuit of this current transformer, and the power meter inserts a burden resistor into the circuit connected to the current transformer, and detects the voltage across this burden resistor.
  • Electric power calculation can be performed by measuring the current value.
  • a pair 5A hereinafter referred to as a pair 5ACT
  • This pair 5ACT is a so-called standardized output method when current measurement of the distribution system is performed, and a flexible power measurement system can be configured by combining with a connectable power meter.
  • most of the power measurement of circuits in the distribution panel has been to measure only the main circuit through which a large current flows.
  • it is branched from the main circuit.
  • It is also necessary to measure the power of the branch circuit which is the terminal circuit in the distribution board. Since the current from the main circuit is divided into this branch circuit, for example, a current of about several tens of A flows.
  • a small current transformer (hereinafter referred to as a small CT) whose output current is about several mA is used instead of 5 ACT. Since the output current of this small CT is about 1000 times that of 5ACT, the iron core and the winding can be miniaturized. Therefore, the compact CT can be used for current measurement of a branch circuit or the like having a relatively low current in the distribution board at a location that cannot be used in the case of the pair 5ACT due to shape restrictions. Thus, it is necessary to use different types of current transformers according to the installation space in the distribution board. Next, the burden resistance connected to the current transformer and provided in the power meter will be described with reference to FIG. As shown in FIG.
  • the burden resistor 154 provided in the current detector 153 of the power measuring instrument 152 as a receiving circuit has a resistance value of several ⁇ . Is used.
  • the current detection unit 153 measures the current value by detecting the voltage across the burden resistor 154 and outputs the current value to the power calculation unit 155.
  • the output current of the pair 5ACT156 is 5A at the maximum, so it is connected to a shunt resistor 157 of several m ⁇ , and the current detection unit 153 detects the voltage across the shunt resistor 157.
  • the current value is measured and output to the power calculation unit 155. JP-A-7-229927
  • Patent Document 1 discloses a current transformer that is easy to assemble, requires a small installation area, has high measurement accuracy, and can be easily adapted to different detected currents.
  • size differs is implement
  • the present invention has been made in view of the above problems, and does not require the trouble of switching the circuit in the power meter, and allows any of a plurality of types of current transformers having different outputs to be connected to the current detection unit.
  • An object of the present invention is to provide a power meter capable of measuring the power of a circuit in a distribution board or the like.
  • a voltage detection unit that detects a voltage signal from a circuit
  • a current detection unit that detects a current signal based on an output from a current transformer attached to the circuit
  • the voltage A power calculation unit that calculates power based on the voltage signal and the current signal detected by the detection unit and the current detection unit, wherein the current detection unit includes at least two types of burden resistors and the variable resistor.
  • a signal processing circuit that performs signal processing on the output from the current transformer, and provides a current measuring unit to which at least two kinds of current transformers having different outputs can be connected.
  • the two types of burden resistors provided in the current detection unit are connected in series, and the two types of current transformers with different outputs are the predetermined positions of the burden resistors connected in series according to the types, or the predetermined positions. It is preferable to be connected to a different predetermined position.
  • Two types of burden resistors provided in the current detection unit are connected in series, and at least one of the burden resistors connected in series is connected to a conduction relay in parallel, and the current transformer Is preferably connected to both ends of the burden resistor connected in series.
  • the current detection unit is connected to one end of the burden resistor connected in series and is connected to a common connection terminal to which a signal line serving as a reference of outputs of the two types of current transformers having different outputs is connected, and the predetermined An individual connection terminal connected to a position and another signal line of the current transformer having two different outputs connected to the other predetermined position, and the signal connected from the individual connection terminal to the power calculation unit It is preferable to further include a multiplexer having a circuit switching function for selecting a line path. Two or more types of load resistors provided in the current detection unit are connected in series, and the load resistors connected in series are not shared by the different types of current transformers, but for each type of current transformer. It is preferable that two individual connection terminals are provided individually.
  • connection terminals provided at both ends of the burden resistor having the largest resistance value have a structure that cannot be connected except for a dedicated connector terminal.
  • the circuit includes a main circuit and a plurality of branch circuits branched from the main circuit, and the current detection unit further includes a plurality of connection terminals connected to signal lines of the current transformers having different outputs of at least two types.
  • the plurality of connection terminals are preferably arranged adjacent to each other for each of these circuits.
  • the plurality of connection terminals include a screw terminal connected to a signal line of the current transformer having a large output and a connector terminal connected to a signal line of the current transformer having a small output, and the signal line of the current transformer It is preferable that the connected plug has a structure that closes the other connection terminal when connected to one of the screw terminal or the connector terminal.
  • Two or more types of burden resistors provided in the current detection unit are connected in series, and a signal line on the reference potential side connected to the burden resistor connected in series is set to a predetermined reference potential other than 0 V that is a ground. It is preferable to connect.
  • the power measuring instrument is preferably capable of measuring multi-circuit power.
  • the current measuring device includes a current detection unit to which at least two types of burden resistors are connected, and the current transformer has a predetermined position of the burden resistor, or What is necessary is just to connect to another predetermined position different from a predetermined position. Therefore, different types of current transformers can be connected to the same power meter, and the power of the circuit in the distribution board can be measured.
  • 1 is an overall configuration diagram of a power measurement system including a power meter according to Embodiment 1 of the present invention. It is a functional block diagram of the power meter. It is a circuit diagram of the electric current detection part with which the said electric power measuring device is equipped. It is a circuit diagram of the electric current detection part with which the electric power meter which concerns on the modification 1 of the said Embodiment 1 is equipped. It is a circuit diagram of the electric current detection part with which the electric power meter which concerns on the modification 2 of the said Embodiment 1 is equipped.
  • the power measurement system S includes a distribution board 1, different types of current transformers 2 a and 2 b, a power meter 3, a monitoring device 4, a load 5, and breakers 6 a, 6 b and 6 c.
  • the power measurement system S monitors the power consumption of various loads 5 such as a lighting fixture or a personal computer that receives power supply from the distribution board 1 in an office building or a general house, for example.
  • FIG. 1 shows a configuration for measuring power from an electric wire using a three-phase three-wire system.
  • current transformers 2a and 2b are attached to the R / T phase and current values are measured. Is shown.
  • the distribution board 1 includes a main circuit that receives commercial power supplied from outside to the building or house on the primary side via the electric wires 7, and a plurality of electric circuits that are installed on the electric circuit branched from the secondary side of the main circuit. And a branch circuit.
  • Each branch circuit is connected to various loads 5 such as an air-conditioning device and an IH (Induction Heating) device in addition to a lighting fixture and a personal computer.
  • loads 5 such as an air-conditioning device and an IH (Induction Heating) device in addition to a lighting fixture and a personal computer.
  • IH Induction Heating
  • the breaker 6a is a main breaker connected to the electric wire 7 of the main circuit
  • the breaker 6b is a branch breaker disposed in a plurality of branch circuits branched from the main circuit.
  • Different types of current transformers 2a and 2b reduce the current of each circuit at a constant rate and supply it to the power meter 3 via the signal line 8 which is a dedicated cable.
  • the current transformer 2a is a 400 / 5A type penetration type
  • the number of turns of the coil is configured so that when a current of 400A flows through the electric wire 7 passing through the center portion, 5A flows through the signal line 8 on the output side. ing.
  • the current transformer 2a is installed to periodically measure the main current flowing through the main circuit through which a relatively large current flows.
  • the current transformer 2a is passed through each electric wire of the main circuit wiring to measure power.
  • the device 3 is connected to the signal line 8.
  • the current transformer 2b is installed in order to periodically measure the branch current flowing through each branch circuit through which a relatively small current flows for each branch circuit, and is passed through a predetermined position of the electric wire of the branch circuit. Connected by signal line 8.
  • the current transformers 2a and 2b can be easily attached to the main circuit 7 and the branch circuit wires 7 by a split type or the like, and by using a dedicated cable as the signal line 8, erroneous connection can be prevented.
  • the power measuring instrument 3 is connected to the current transformers 2a and 2b, and has a burden resistor to be inserted into a circuit connected to the current transformers 2a and 2b.
  • the power measuring instrument 3 supplies the power of the circuit in which the current transformers 2a and 2b are installed. measure.
  • the power meter 3 outputs the calculation result to the monitoring device 4 via the communication line.
  • the power measuring instrument 3 has a size of 10 ⁇ 10 cm, for example, and is installed at a predetermined location in the distribution board 1.
  • the monitoring device 4 is a dedicated personal computer or the like having a monitor, and is a monitoring unit that manages and displays energization information of each branch circuit.
  • the monitoring device 4 is connected to the power meter 3 via RS-485 communication or the like, collects data related to the power usage of each load 5, and displays a graph or the like for data analysis.
  • the monitoring device 4 automatically records, for example, data relating to power usage every hour or every day, performs collective energy management via a network connected to the power meter 3, and “visible” the efficient power usage is seen. Realization.
  • the load 5 is various electric devices such as an air conditioner and an IH device, in addition to a lighting device and a personal computer connected to the branch circuit.
  • FIG. 2 shows a configuration for power measurement for one current transformer 2a or 2b for convenience.
  • the power meter 3 includes a current detector 31 that detects a current signal from signals from the current transformers 2a and 2b, a voltage detector 32 that detects a voltage signal of the circuit, and a current and voltage detector 32 in the current detector 31.
  • a power calculation unit 33 that calculates power based on each voltage signal is provided.
  • the current detection unit 31 includes a burden resistor 311 inserted in a circuit connected to the current transformers 2a and 2b, a filter 312 that passes a signal in a predetermined frequency band, and a voltage value of a current signal that has passed through the filter 312 to a predetermined value.
  • An adder circuit 313 is provided.
  • the voltage detector 32 is connected to the electric wire 7 via a breaker 6c shown in FIG.
  • the power calculator 33 supplies the load 5 connected to the electric wire 7 to which the current transformers 2a and 2b are attached. It is a microcomputer that calculates the electric power.
  • the power calculation unit 33 includes A / D conversion units 331 and 332, a multiplication unit 333, and a transmission circuit unit 334.
  • the A / D converter 331 converts the analog signal received from the voltage detector 32 into a digital signal.
  • the A / D converter 332 converts the analog signal received from the current detector 31 into a digital signal.
  • the multiplier 333 is a circuit that multiplies the signals output from the A / D converters 331 and 332, that is, calculates power.
  • the transmission circuit unit 334 includes, for example, a two-wire serial communication circuit compliant with RS485 and transmits a power calculation value to the monitoring device 4 that can communicate with each other via a connected communication line.
  • the current detection unit 31 includes two types of burden resistors 311a and 311b connected in series and having different resistance values.
  • the burden resistor 311a is a 2.0 ⁇ resistor
  • the burden resistor 311b is a 1 m ⁇ shunt resistor.
  • the shunt resistor is a highly accurate resistor with a small resistance value made for current measurement of a circuit through which a large current flows.
  • the current detection unit 31 includes two types of burden resistors that can be connected to the two types of current transformers 2a and 2b, but three types that can be connected to three or more types of current transformers with different outputs. You may provide the above burden resistance.
  • the signal line on the reference potential side connected to the burden resistors 311a and 311b is connected to the 0V ground (GND) 314, and one end of the burden resistor 311a is connected to the adder circuit 313 side.
  • the current detection unit 31 includes a signal processing circuit that measures the voltages at both ends of the load resistors 311a and 311b inserted in the circuit and obtains a current value.
  • the power measuring instrument 3 includes connection terminals 3a to 3c that are connected to the ends of the load resistors 311a and 311b, respectively.
  • the current transformers 2a and 2b have two different outputs as described above, and the current transformers 2a and 2b are arranged at the extreme ends of the load resistors 311a and 311b connected in series according to the type. Or it connects to the predetermined position between the one end part of burden resistance 311a, 311b connected in series and burden resistance 311a, 311b. That is, the signal line from the pair 5ACT 2a that outputs a relatively large current is connected to the connection terminals 3b and 3c because it is necessary to reduce the burden resistance inserted in the circuit.
  • connection terminals 3a and 3c Connected to.
  • the connection terminal 3c is a common terminal for connecting the signal lines serving as the reference of the outputs of the current transformers 2a and 2b
  • the connection terminal 3a is an individual terminal for connecting other signal lines of the current transformer 2b
  • the connection terminal 3b is an individual terminal for connecting the other signal line of the current transformer 2a.
  • the connection positions of the signal lines of the different types of current transformers 2a and 2b are set according to the resistance values of the load resistors 311a and 311b connected in series. It can be adjusted by changing the connection terminals 3a to 3c provided. For this reason, in the electric power measuring device 3, the effort which switches a circuit is not required, the current transformers 2a and 2b from which an output differs can be connected to the same electric current detection part 31, and the electric power of the circuit in the distribution board 1 is made.
  • the current measuring device 3 can be reduced in size and cost.
  • the monitoring device 4 connected to the power meter 3 can “visualize” the power consumption of the load 5 and visually understand which load 5 the power should be reduced.
  • connection terminals 3a and 3c are respectively connected to the extreme ends of the load resistors 311a and 311b connected in series, and the current transformers 2a and 2b having different outputs are connected to the same connection terminals 3a and 3c.
  • a load resistor 311a having a large resistance value is arranged on the reference potential 314 side.
  • the second modification of the first embodiment is similar to the first embodiment except that, for example, a manually controlled multiplexer 316 is added to both ends of the burden resistor 311a.
  • the current detection unit 31 is connected to predetermined positions (that is, both ends of the load resistor 311a) at the ends of the two types of load resistors 311a and 311b connected in series, and power is supplied from the connection terminals 3a to 3c.
  • a multiplexer 316 having a circuit switching function for selecting a path of a signal line connected to the calculation unit 33 is further provided.
  • the signal multiplexer 316 is used as the circuit switch, and the current transformers 2a and 2b having different outputs can be connected to the same current detection unit 31.
  • the power of the circuit in the panel can be measured. Therefore, it is possible to reduce the size and cost of the power measuring instrument 3.
  • the current detection unit 31 further includes a programmable gain amplifier 317 capable of changing a signal amplification factor.
  • the programmable gain amplifier 317 is an amplifier circuit that can set the amplification factor from the outside using an analog switch or the like.
  • the outputs of the current transformers 2a and 2b differ depending on the rated current.
  • the gain is switched using the programmable gain amplifier 317, and a signal is input to the adder circuit 313 with an optimum signal.
  • the power calculation unit 33 can calculate the power.
  • a fourth modification of the first embodiment will be described with reference to FIG.
  • a signal line on the reference potential side connected to the burden resistors 311a and 311b is connected to a predetermined reference potential Vref other than 0V that is a ground.
  • the current detector 31 is connected to one end of each of the two load resistors 311a and 311b arranged in parallel, and is connected to the other end of the load resistors 311a and 311b to output the current transformers 2a and 2b.
  • the signal lines of the current transformers 2a and 2b are connected to the connection terminals 3a and 3c connected to both ends of the load resistors 311a and 311b connected in parallel, regardless of the type. For this reason, in this Embodiment 2, even if any of current transformer 2a, 2b is connected to the electric power measuring device 3, the appropriate load resistance according to the kind of current transformer 2a, 2b by the circuit switch 318 is shown. 311a and 311b can be connected. Therefore, the signal level of the current detection signal is raised to a predetermined level, the S / N ratio is improved, and the power can be accurately measured. (Embodiment 3) A power meter according to Embodiment 3 of the present invention will be described with reference to FIG.
  • connection terminals 3b and 3d provided between the load resistors 311a and 311b connected in series of the current detection unit 31 are not shared by the different types of current transformers 2a and 2b. Provided separately. That is, as shown in FIG. 9, the connection terminals 3a and 3d are connected to the signal line of the small CT 2b, and the connection terminals 3b and 3c are connected to the signal line of the pair 5ACT 2a.
  • the current transformers 2a and 2b having different outputs can be connected to the same current detection unit 31, the power of the circuit in the distribution board can be measured, and the current flow path from the current transformers 2a and 2b flows. Can be completely separated, and more accurate power measurement becomes possible.
  • connection terminals 3a and 3d connected to both ends of the burden resistor 311a having a larger resistance value are fitted to a structure in which only the dedicated connector terminal (plug) 9a can be connected, that is, the shape of the connector terminal 9a.
  • the connector shape is 3e.
  • the pair 5ACT 2a is connected to the burden resistor 311a having a large resistance value, and the burden resistor 311a is burned out, thereby preventing an accident due to erroneous connection.
  • the construction between the current transformers 2a and 2b and the power measuring device 3 can be improved by adopting the structure of the connector terminal 9a.
  • the connector terminal (plug) 9b has a structure to which signal lines from two or more current transformers (two small CTs 2b in this figure) can be connected.
  • the power measuring instrument 3 is formed with a connector connecting terminal 3f having a shape that fits with the connector terminal 9b on the side surface thereof.
  • FIG. 12 (a) is a front view of a power meter according to Embodiment 4 of the present invention
  • FIG. 12 (b) is a bottom view of the power meter
  • FIG. 12 (c) is a top view of the power meter. is there.
  • the power meter 3 according to the fourth embodiment includes a display unit 10, a switch unit 11, a voltage input terminal 12, a communication terminal 13, a pair 5ACT connection terminal 14, and a small CT connection terminal 15.
  • the display unit 10 is a liquid crystal panel or the like that displays a power measurement result in each circuit.
  • the switch unit 11 is an operation key for setting the types of the current transformers 2 a and 2 b and setting the display of the display unit 10.
  • the voltage input terminal 12 is an input terminal that is connected to an electric wire and detects a correlation voltage between the voltage electrode S and the voltage electrode T.
  • the communication terminal 13 is a screw terminal that is connected to the monitoring device 4 and connects a communication line used for RS-485 communication or the like.
  • the pair 5ACT connection terminal 14 is a screw terminal for connecting a signal line from the pair 5ACT2a.
  • the small CT connection terminal 15 is a connector terminal serving as an insertion port into which the connector terminal 9a from the small CT 2b is inserted.
  • a circuit composed of a main circuit and a plurality of branch circuits branched from the main circuit is arranged on the side surface of the power meter 3 adjacent in the left-right direction. And as shown to the area
  • connection terminals 14 that are screw terminals for connecting a signal line of a current transformer 2a having a large output and a signal line of a current transformer 2b having a small output.
  • a plurality of connection terminals 15 that are connector terminals are provided.
  • FIGS. 13A to 13C when the plug 16 connected to the signal line of the current transformers 2a and 2b is inserted into the connection terminal 15, the connector terminal 16b is inserted.
  • a projection 16a that closes the connection terminal 14 that is a screw terminal.
  • the plug 16 is described as having a protrusion 16a.
  • the plug 16 may have any structure as long as the connection terminal can be blocked. With this configuration, two types of current transformers 2a and 2b are not simultaneously connected in the same circuit, and erroneous connection due to simultaneous connection of the small CT 2b and the pair 5ACT 2a can be prevented.
  • the structure of the plug 16 is a structure that closes the connection terminal 15 that is a connector terminal when the connection terminal 14 that is a screw terminal is connected.
  • the main circuit and the branch circuit in the distribution board are measured, the main circuit has a larger rated current, so it is 5 ACT2a, and the branch circuit has a relatively low rated current, so a small CT 2b is selected and measured. Therefore, in the power meter 3, since the predetermined circuit is a selection formula of only the connection terminal 14 of the 5ACT2a and the predetermined circuit is a selection formula of the connection terminal 15 of the small CT2b or the connection terminal 14 of the pair 5ACT2a, all the circuits are selective formulas. It can be configured at a lower cost than the structure of the connection terminals 14 and 15. Although not shown, it is also conceivable that a part of the measurement circuit has only the connection terminal 15 for the small CT 2b.
  • the power measuring device 3 includes a plurality of connection terminal sets for measuring the power of a circuit composed of a main circuit and a branch circuit, and enables multi-circuit power measurement. This is because, when measuring from the main circuit to the branch circuit, it is necessary to measure a plurality of rated currents, and the power meter 3 can be miniaturized by enabling multi-circuit power measurement.
  • the present invention is not limited to the configuration of the embodiment described above, and various modifications can be made without departing from the spirit of the invention.
  • the types of current transformers 2a and 2b and burden resistors 311a and 311b are not limited to two types, and may be at least two types.
  • the type of current transformer is not limited to 5 ACT or small CT, and current transformers with rated currents of 50A, 250A, 600A can be used.
  • various types of different current transformers may be connected to a predetermined position of a plurality of burden resistors connected in series or another predetermined position different from the predetermined position, depending on the type. It is not limited to the positions at the extreme ends.
  • all of the above-described embodiments and their modifications can be combined with each other.
  • the preferred embodiments of the present invention have been described above, but the present invention is not limited to these specific embodiments, and various changes and modifications can be made without departing from the scope of the claims. It is also within the scope of the present invention.

Abstract

An electricity meter (3) comprises: a current detection unit (31) that detects a current signal on the basis of output from a current transformers (2a, 2b); a voltage detection unit (32) that detects a voltage signal; and a power calculation unit (33) that calculates power on the basis of the voltage and current signals detected by the voltage detection unit (32) and current detection unit (31). The current detection unit (31) is provided with load resistors (311a, 311b). The current transformers (2a, 2b) have two types of different output, and depending on the type, are connected to the connection terminals (3a to 3c) on both ends of the load resistors (311a, 311b) or between the load resistors (311a and 311b). As a result of this configuration, the electricity meter (3) can connect current transformer (2a) and/or (2b), and can measure the electric power of a circuit within a distribution board.

Description

電力計測器Power meter
　本発明は、変流器（ＣＴ：Ｃｕｒｒｅｎｔ　Ｔｒａｎｓｆｏｒｍｅｒ）に接続されて分電盤内などにおける回路の電力を計測する電力計測器に関する。 The present invention, current transformers: a power measuring device (CT Current Transformer) to be connected to measure the power of the circuit in such distribution board inside.
　従来より、ビルディングなどの施設に設けられた分電盤内における回路の電力を計測する際、測定範囲拡大のために変流器が用いられる。この変流器の受け側回路には電力計測器が接続され、電力計測器は、変流器と接続される回路に負担抵抗を挿入して、この負担抵抗の両端の電圧を検出することで電流値を計測して電力演算を行うことができる。
　工場等では百Ａ~数百Ａの交流電流が通電されており、定格電流を通電すると５Ａの出力電流が得られる対５Ａと呼ばれる変流器（以下、対５ＡＣＴと記す）が使用される。この対５ＡＣＴは、配電系統の電流計測を行う際、いわゆる規格化された出力方式であり、接続可能な電力計測器と組み合わせることで、柔軟な電力計測システムの構成が可能となる。
　分電盤内における回路の電力計測には、従来、大きな電流が流れる主幹回路のみを計測する場合が殆どであるが、近年の消費電力の「見える化」の実現などのため、主幹回路から分岐された分電盤内の末端回路である分岐回路の電力も計測する必要がある。この分岐回路には、主幹回路からの電流が分流されるため、例えば数十Ａ程度の電流が流れる。なお、電力の「見える化」では、分電盤内の回路ごとの電力の情報を、ＬＡＮ経由でモニタを備えた管理装置などに表示する。
　そして、上記の対５ＡＣＴは、数百Ａといった定格電流の通電時に５Ａを出力するため、コアを大きくする必要があり、比較的形状が大きくなる。従って、定格電流が低い、分岐回路における数十Ａ程度の電流計測において、電流が通電される計測箇所に対５ＡＣＴを取付けようとした場合、形状が大きいために、取付けできない。また、分電盤内の複数の分岐回路の全ての電力計測を対５ＡＣＴで行うことは、分電盤内のスペース上問題がある。
　このため、分岐回路の電流計測においては、対５ＡＣＴではなく、出力電流が数ｍＡ程度である小型の変流器（以下、小型ＣＴと記す）が用いられる。この小型ＣＴの出力電流は、対５ＡＣＴの約１０００分の一であるため、鉄心コアや巻き線を小型化することができる。それゆえ、小型ＣＴは、分電盤内の比較的電流の低い分岐回路等の電流計測用として、対５ＡＣＴでは形状の制約上用いることができない箇所に用いることが可能となる。このように、分電盤内の設置スペースに応じて、種類の異なる変流器を使い分ける必要がある。
　次に、変流器に接続され、電力計測器に備わる負担抵抗に関して図１５を参照して説明する。図１５（ａ）に示すように、小型ＣＴ１５１は出力電流が数ｍＡとなるため、受け側回路である電力計測器１５２の電流検出部１５３に備える負担抵抗１５４には数Ωの抵抗値のものを用いる。電流検出部１５３は、この負担抵抗１５４の両端の電圧を検出することで電流値を計測し、電力演算部１５５に出力する。一方、図１５（ｂ）に示すように、対５ＡＣＴ１５６では出力電流が最大５Ａとなるため、数ｍΩのシャント抵抗１５７に接続され、電流検出部１５３は、このシャント抵抗１５７の両端の電圧を検出することで電流値を計測し、電力演算部１５５に出力する。
特開平７−２２９９２７号公報 Conventionally, when measuring the power of a circuit in a distribution board provided in a facility such as a building, a current transformer is used to expand the measurement range. A power meter is connected to the receiving circuit of this current transformer, and the power meter inserts a burden resistor into the circuit connected to the current transformer, and detects the voltage across this burden resistor. Electric power calculation can be performed by measuring the current value.
In factories and the like, an alternating current of hundred to several hundreds of A is energized, and a current transformer called a pair 5A (hereinafter referred to as a pair 5ACT) that can obtain an output current of 5A when a rated current is passed is used. This pair 5ACT is a so-called standardized output method when current measurement of the distribution system is performed, and a flexible power measurement system can be configured by combining with a connectable power meter.
In the past, most of the power measurement of circuits in the distribution panel has been to measure only the main circuit through which a large current flows. However, in order to realize “visualization” of power consumption in recent years, it is branched from the main circuit. It is also necessary to measure the power of the branch circuit which is the terminal circuit in the distribution board. Since the current from the main circuit is divided into this branch circuit, for example, a current of about several tens of A flows. In the “visualization” of power, information on the power for each circuit in the distribution board is displayed on a management device equipped with a monitor via the LAN.
And since said pair 5ACT outputs 5A at the time of energization of the rated current of several hundred A, it is necessary to enlarge a core, and a shape becomes comparatively large. Therefore, in a current measurement of about several tens of A in a branch circuit with a low rated current, when it is attempted to attach a pair 5ACT to a measurement location where current is applied, the shape is large and cannot be attached. In addition, there is a problem in terms of space in the distribution board that all power measurements of a plurality of branch circuits in the distribution board are performed with 5 ACT.
For this reason, in the current measurement of the branch circuit, a small current transformer (hereinafter referred to as a small CT) whose output current is about several mA is used instead of 5 ACT. Since the output current of this small CT is about 1000 times that of 5ACT, the iron core and the winding can be miniaturized. Therefore, the compact CT can be used for current measurement of a branch circuit or the like having a relatively low current in the distribution board at a location that cannot be used in the case of the pair 5ACT due to shape restrictions. Thus, it is necessary to use different types of current transformers according to the installation space in the distribution board.
Next, the burden resistance connected to the current transformer and provided in the power meter will be described with reference to FIG. As shown in FIG. 15A, since the small CT 151 has an output current of several mA, the burden resistor 154 provided in the current detector 153 of the power measuring instrument 152 as a receiving circuit has a resistance value of several Ω. Is used. The current detection unit 153 measures the current value by detecting the voltage across the burden resistor 154 and outputs the current value to the power calculation unit 155. On the other hand, as shown in FIG. 15 (b), the output current of the pair 5ACT156 is 5A at the maximum, so it is connected to a shunt resistor 157 of several mΩ, and the current detection unit 153 detects the voltage across the shunt resistor 157. Thus, the current value is measured and output to the power calculation unit 155.
JP-A-7-229927
　このように、小型ＣＴ及び対５ＡＣＴなどの種類の異なる変流器は、その出力電流がそれぞれ大きく異なるため、接続される回路の負担抵抗の抵抗値が異なる。具体的には、図１５に示すように、小型ＣＴ１５１と対５ＡＣＴ１５６とでは出力電流の大きさが１０００倍程度の差があり、対５ＡＣＴ１５６に接続される負担抵抗は数ｍΩ、小型ＣＴ１５１に接続される負担抵抗は数Ωとなる。このため、種類の異なる変流器を使用して回路の電力計測を行うには、変流器の種類に応じて、入力端子をそれぞれの出力電流の大きさで分けた別々の計測回路部、又は別々の電力計測器が必要となり、コストを要するという問題がある。
　ここで、組立てが容易で、取付所要面積が小さい、測定精度の高い、また被検出電流の大きさが異なっても容易に適合できる変流器が特許文献１に開示されている。
　しかしながら、上記特許文献１では、変流器を１種類使用して、抵抗器を切り替えることで大きさの異なる電流測定を実現するものであり、種類の異なる変流器を用いて電力を計測するものではない。 As described above, different types of current transformers such as the small CT and the pair 5 ACT have different output currents, so that the resistance values of the burden resistors of the connected circuits are different. Specifically, as shown in FIG. 15, there is a difference of about 1000 times in the output current between the small CT 151 and the pair 5 ACT 156, and the burden resistance connected to the pair 5 ACT 156 is several mΩ and is connected to the small CT 151. The burden resistance is several Ω. For this reason, in order to measure the power of the circuit using different types of current transformers, according to the type of current transformer, separate measurement circuit units that divide the input terminal by the size of each output current, Alternatively, there is a problem that a separate power meter is required and costs are increased.
Here, Patent Document 1 discloses a current transformer that is easy to assemble, requires a small installation area, has high measurement accuracy, and can be easily adapted to different detected currents.
However, in the said patent document 1, the current measurement from which a magnitude | size differs is implement | achieved by using one type of current transformers and switching a resistor, and electric power is measured using different types of current transformers. It is not a thing.
　本発明は、上記課題に鑑みてなされたものであり、電力計測器内の回路切替を行う手間を要せず、出力の異なる複数種の変流器のいずれをも電流検出部に接続可能とし、分電盤内などにおける回路の電力を計測できる電力計測器を提供することを目的とする。
　本発明の一実施の形態によれば、回路から電圧信号を検出する電圧検出部と、前記回路に取り付けられた変流器からの出力に基づいて電流信号を検出する電流検出部と、前記電圧検出部及び電流検出部で検出される電圧信号及び電流信号に基づいて電力演算する電力演算部と、を備える電力計測器において、前記電流検出部は、少なくとも２種類以上の負担抵抗と、前記変流器からの出力を信号処理する信号処理回路とを備え、前記電流検出部には、少なくとも２種類以上の出力の異なる変流器が接続できる電力計測器を提供する。
　前記電流検出部に備えられる２種類の負担抵抗は直列に接続され、前記２種類の出力の異なる変流器はその種類に応じて前記直列に接続された負担抵抗の所定位置、又は前記所定位置と異なる別の所定位置に接続される、ことが好ましい。
　前記電流検出部に備えられる２種類の負担抵抗は直列に接続され、前記直列に接続された負担抵抗のうち少なくとも１つの負担抵抗には、導通用のリレーが並列に接続され、前記変流器は前記直列に接続された負担抵抗の最両端に接続される、ことが好ましい。
　前記電流検出部は、前記直列接続された負担抵抗の一端部に接続されて前記２種類の出力の異なる変流器の出力の基準となる信号線が接続される共通の接続端子、及び前記所定位置及び前記別の所定位置に接続されて前記２種類の出力の異なる変流器の他の信号線が接続される個別の接続端子と、前記個別の接続端子から前記電力演算部に繋がる前記信号線の経路を選択する回路切替機能を有したマルチプレクサと、をさらに備える、ことが好ましい。
　前記電流検出部に備えられる２種類以上の負担抵抗は直列に接続され、前記直列に接続された負担抵抗間には、前記異なる種類の変流器で共用とせず、変流器の種類ごとに個別に２つの個別接続端子が設けられる、ことが好ましい。
　前記直列に接続された少なくとも２種類以上の負担抵抗のうち、抵抗値の最も大きな前記負担抵抗の両端に設けられる接続端子は、専用のコネクタ端子以外は接続できない構造を有する、ことが好ましい。
　前記回路は、主幹回路及び当該主幹回路から分岐した複数の分岐回路を含み、前記電流検出部は、前記少なくとも２種類以上の出力の異なる変流器の信号線に接続する複数の接続端子をさらに備え、前記複数の接続端子は、これら回路ごとに、隣接して配置される、ことが好ましい。
　前記複数の接続端子は、出力の大きな前記変流器の信号線に接続するネジ端子、及び出力の小さな前記変流器の信号線に接続するコネクタ端子を含み、前記変流器の信号線と接続されたプラグは、前記ネジ端子又は前記コネクタ端子の一方との接続を行うと、他方の接続端子を塞ぐ構造を有する、ことが好ましい。
　前記電流検出部に備えられる２種類以上の負担抵抗は直列に接続され、前記直列に接続された負担抵抗に接続される基準電位側の信号線を、グランドである０Ｖ以外の所定の基準電位に接続する、ことが好ましい。
　前記電力計測器は、多回路の電力計測が可能である、ことが好ましい。
　前記電流検出部に備えられる２種類以上の負担抵抗は並列に接続され、前記電流検出部は、前記並列に配置された負担抵抗の一端側に接続され、前記変流器の出力の電流経路を前記並列に接続された負担抵抗のいずれかの経路に切り替える回路切替器をさらに備え、前記少なくとも２種類以上の出力の異なる変流器は、前記並列に接続された負担抵抗の両端側に接続される、ことが好ましい。
発明の効果
　本発明に係る電力計測器によれば、少なくとも２種類以上の負担抵抗が接続された電流検出部を備え、変流器は、その種類に応じて、負担抵抗の所定位置、又は当該所定位置と異なる別の所定位置に接続すればよい。従って、種類の異なる変流器を同一の電力計測器に接続可能となり、分電盤内などにおける回路の電力を計測することができる。 The present invention has been made in view of the above problems, and does not require the trouble of switching the circuit in the power meter, and allows any of a plurality of types of current transformers having different outputs to be connected to the current detection unit. An object of the present invention is to provide a power meter capable of measuring the power of a circuit in a distribution board or the like.
According to an embodiment of the present invention, a voltage detection unit that detects a voltage signal from a circuit, a current detection unit that detects a current signal based on an output from a current transformer attached to the circuit, and the voltage A power calculation unit that calculates power based on the voltage signal and the current signal detected by the detection unit and the current detection unit, wherein the current detection unit includes at least two types of burden resistors and the variable resistor. And a signal processing circuit that performs signal processing on the output from the current transformer, and provides a current measuring unit to which at least two kinds of current transformers having different outputs can be connected.
The two types of burden resistors provided in the current detection unit are connected in series, and the two types of current transformers with different outputs are the predetermined positions of the burden resistors connected in series according to the types, or the predetermined positions. It is preferable to be connected to a different predetermined position.
Two types of burden resistors provided in the current detection unit are connected in series, and at least one of the burden resistors connected in series is connected to a conduction relay in parallel, and the current transformer Is preferably connected to both ends of the burden resistor connected in series.
The current detection unit is connected to one end of the burden resistor connected in series and is connected to a common connection terminal to which a signal line serving as a reference of outputs of the two types of current transformers having different outputs is connected, and the predetermined An individual connection terminal connected to a position and another signal line of the current transformer having two different outputs connected to the other predetermined position, and the signal connected from the individual connection terminal to the power calculation unit It is preferable to further include a multiplexer having a circuit switching function for selecting a line path.
Two or more types of load resistors provided in the current detection unit are connected in series, and the load resistors connected in series are not shared by the different types of current transformers, but for each type of current transformer. It is preferable that two individual connection terminals are provided individually.
Of the at least two types of burden resistors connected in series, it is preferable that the connection terminals provided at both ends of the burden resistor having the largest resistance value have a structure that cannot be connected except for a dedicated connector terminal.
The circuit includes a main circuit and a plurality of branch circuits branched from the main circuit, and the current detection unit further includes a plurality of connection terminals connected to signal lines of the current transformers having different outputs of at least two types. The plurality of connection terminals are preferably arranged adjacent to each other for each of these circuits.
The plurality of connection terminals include a screw terminal connected to a signal line of the current transformer having a large output and a connector terminal connected to a signal line of the current transformer having a small output, and the signal line of the current transformer It is preferable that the connected plug has a structure that closes the other connection terminal when connected to one of the screw terminal or the connector terminal.
Two or more types of burden resistors provided in the current detection unit are connected in series, and a signal line on the reference potential side connected to the burden resistor connected in series is set to a predetermined reference potential other than 0 V that is a ground. It is preferable to connect.
The power measuring instrument is preferably capable of measuring multi-circuit power.
Two or more types of burden resistors provided in the current detection unit are connected in parallel, and the current detection unit is connected to one end side of the load resistors arranged in parallel, and the current path of the output of the current transformer is It further comprises a circuit switcher for switching to one of the paths of the burden resistors connected in parallel, and the at least two types of current transformers having different outputs are connected to both ends of the load resistors connected in parallel. It is preferable that
Advantageous Effects of Invention According to the power measuring instrument of the present invention, the current measuring device includes a current detection unit to which at least two types of burden resistors are connected, and the current transformer has a predetermined position of the burden resistor, or What is necessary is just to connect to another predetermined position different from a predetermined position. Therefore, different types of current transformers can be connected to the same power meter, and the power of the circuit in the distribution board can be measured.
　本発明の目的及び特徴は以下のような添付図面と好ましい実施例の説明により明確になる。
本発明の実施の形態１に係る電力計測器を備えた電力計測システムの全体構成図である。 上記電力計測器の機能ブロック図である。 上記電力計測器に備わる電流検出部の回路図である。 上記実施の形態１の変形例１に係る電力計測器に備わる電流検出部の回路図である。 上記実施の形態１の変形例２に係る電力計測器に備わる電流検出部の回路図である。 上記実施の形態１の変形例３に係る電力計測器に備わる電流検出部の回路図である。 上記実施の形態１の変形例４に係る電力計測器に備わる電流検出部の回路図である。 本発明の実施の形態２に係る電力計測器に備わる電流検出部の回路図である。 本発明の実施の形態３に係る電力計測器に備わる電流検出部の回路図である。 上記実施の形態３の変形例１に係る電力計測器に備わる電流検出部の回路図である。 上記実施の形態３の変形例２に係る電力計測器に備わる電流検出部の回路図である。 （ａ）本発明の実施の形態４に係る電力計測器の正面図、（ｂ）同電力計測器の下面図、（ｃ）同電力計測器の上面図である。 （ａ）上記実施の形態４の変形例１に係る電力計測器に接続される変流器のプラグの側面図、（ｂ）同プラグの斜視図、（ｃ）同プラグの別の側面図である。 （ａ）上記実施の形態４の変形例２に係る電力計測器の正面図、（ｂ）同電力計測器の下面図、（ｃ）同電力計測器の上面図である。 （ａ）従来の電力計測器における電流検出部の回路図、（ｂ）従来の別の電力計測器における電流検出部の回路図である。 The objects and features of the present invention will become apparent from the following drawings and description of preferred embodiments.
1 is an overall configuration diagram of a power measurement system including a power meter according to Embodiment 1 of the present invention. It is a functional block diagram of the power meter. It is a circuit diagram of the electric current detection part with which the said electric power measuring device is equipped. It is a circuit diagram of the electric current detection part with which the electric power meter which concerns on the modification 1 of the said Embodiment 1 is equipped. It is a circuit diagram of the electric current detection part with which the electric power meter which concerns on the modification 2 of the said Embodiment 1 is equipped. It is a circuit diagram of the electric current detection part with which the electric power measuring device which concerns on the modification 3 of the said Embodiment 1 is equipped. It is a circuit diagram of the electric current detection part with which the electric power meter which concerns on the modification 4 of the said Embodiment 1 is equipped. It is a circuit diagram of the electric current detection part with which the electric power meter which concerns on Embodiment 2 of this invention is equipped. It is a circuit diagram of the electric current detection part with which the electric power measuring device which concerns on Embodiment 3 of this invention is equipped. It is a circuit diagram of the electric current detection part with which the electric power meter which concerns on the modification 1 of the said Embodiment 3 is equipped. It is a circuit diagram of the electric current detection part with which the electric power meter which concerns on the modification 2 of the said Embodiment 3 is equipped. (A) The front view of the electric power meter which concerns on Embodiment 4 of this invention, (b) The bottom view of the electric power meter, (c) The top view of the electric power meter. (A) The side view of the plug of the current transformer connected to the electric power meter which concerns on the modification 1 of the said Embodiment 4, (b) The perspective view of the plug, (c) With another side view of the plug is there. (A) The front view of the electric power measuring device which concerns on the modification 2 of the said Embodiment 4, (b) The bottom view of the same electric power measuring device, (c) The top view of the same electric power measuring device. (A) Circuit diagram of current detector in conventional power meter, (b) Circuit diagram of current detector in another conventional power meter.
　以下、本発明の実施の形態について添付図面に基づいて説明する。図面全体において同一又は類似する部分については同一参照符号を付して説明を省略する。
　（実施の形態１）
　本発明の実施の形態１に係る電力計測器について図面を参照して説明する。図１に示すように、電力計測システムＳは、分電盤１、種類の異なる変流器２ａ，２ｂ、電力計測器３、監視装置４、負荷５、及びブレーカ６ａ，６ｂ，６ｃを備える。この電力計測システムＳは、例えばオフィスビル内や一般住宅内において、分電盤１から電力供給を受ける照明器具やパソコンなどの様々な負荷５の消費電力を監視する。ここで、図１は三相３線式を用いる電線などからの電力計測のための構成を示しており、例えば、Ｒ／Ｔ相に変流器２ａ，２ｂを取付け、電流値を計測することを示している。
　分電盤１は、外部からビル内や宅内に供給される商用電源を、電線７を介して一次側に受ける主幹回路と、主幹回路の２次側から分岐した電路に介装される複数の分岐回路とを備える。各分岐回路には照明器具やパソコンのほか、空調機器やＩＨ（誘導加熱、Ｉｎｄｕｃｔｉｏｎ　Ｈｅａｔｉｎｇ）機器などの様々な負荷５が接続される。また、ブレーカ６ａは、主幹回路の電線７に接続された主幹ブレーカであり、ブレーカ６ｂは、主幹回路から分岐した複数の分岐回路に配設された分岐ブレーカである。
　種類の異なる変流器２ａ，２ｂは、各回路の電流を一定の割合で小さくして専用ケーブルである信号線８を介して電力計測器３に供給する。例えば変流器２ａは４００／５Ａ型の貫通式であれば、中心部を貫通する電線７に４００Ａの電流が流れた時に出力側の信号線８に５Ａが流れるようコイルの巻き数が構成されている。
　変流器２ａは、比較的大きな電流の流れる主幹回路を流れる主幹電流を定期的に計測するために設置され、本図においては、主幹回路の配線の１本ずつの電線に貫通され、電力計測器３と信号線８にて接続される。変流器２ｂは、比較的小さな電流の流れる各分岐回路を流れる分岐電流を分岐回路毎に定期的に計測するために設置され、分岐回路の電線の所定位置に貫通され、電力計測器３と信号線８にて接続される。なお、変流器２ａ，２ｂは、分割式などで主幹回路及び分岐回路の電線７に簡単に取り付けられ、信号線８として専用ケーブルを用いることで誤結線を未然に防止できる。
　電力計測器３は、変流器２ａ，２ｂと接続され、これら変流器２ａ，２ｂと接続される回路に挿入する負担抵抗を備え、変流器２ａ，２ｂが設置された回路の電力を計測する。電力計測器３は、通信線を介して監視装置４に演算結果を出力する。この電力計測器３は、例えば１０×１０ｃｍの大きさであり、分電盤１内の所定箇所に設置される。
　監視装置４は、モニタを有する専用のパソコンなどであり、各分岐回路の通電情報を管理し表示する監視ユニットである。監視装置４は、電力計測器３とＲＳ−４８５通信などでネットワーク接続され、各負荷５の電力使用に関するデータ収集を行い、データ解析のためグラフなどの表示を行う。監視装置４は、例えば一時間ごとや一日ごとの電力使用に関するデータを自動記録し、電力計測器３と接続されたネットワーク経由によるエネルギーの一括管理を行い、効率のよい電力使用量の「見える化」を実現する。
　負荷５は、分岐回路に接続された照明器具やパソコンのほか、空調機器やＩＨ機器などの様々な電気機器である。
　次に、本実施の形態１に係る電力計測器３の機能構成に関して図２を参照して説明する。図２は、便宜上、１つの変流器２ａまたは変流器２ｂについての電力計測のための構成を示している。電力計測器３は、変流器２ａ，２ｂの信号から電流信号を検出する電流検出部３１、回路の電圧信号を検出する電圧検出部３２、及び電流検出部３１における電流及び電圧検出部３２における電圧の各信号に基づいて電力演算する電力演算部３３を備える。
　電流検出部３１は、変流器２ａ，２ｂと接続される回路に挿入された負担抵抗３１１、所定周波数帯の信号を通過させるフィルタ３１２、及びフィルタ３１２を通過した電流信号の電圧値に所定値を加算する加算回路３１３を備える。
　電圧検出部３２は、図１に示すブレーカ６ｃなどを介して電線７と端子で接続され、電圧降圧回路３２１、フィルタ３２２、及び加算回路３２３を備える。電圧降圧回路３２１は、電圧を降圧させ、フィルタ３２２は、所定周波数帯の電圧信号を通過させ、加算回路３２３は、電圧波形が例えば０~５Ｖの範囲となるように電圧信号に適切なバイアスをかける。
　電力演算部３３は、電流検出部３１で計測された電流、及び電圧検出部３２で検出される電圧に基づいて、変流器２ａ，２ｂが取付けられた電線７に接続された負荷５に供給される電力を演算するマイコンである。この電力演算部３３は、Ａ／Ｄ変換部３３１，３３２、乗算部３３３、及び伝送回路部３３４を備える。
　Ａ／Ｄ変換部３３１は、電圧検出部３２から受信するアナログ信号をデジタル信号に変換する。Ａ／Ｄ変換部３３２は、電流検出部３１から受信するアナログ信号をデジタル信号に変換する。乗算部３３３は、Ａ／Ｄ変換部３３１及び３３２から出力される信号を乗算する回路であり、すなわち電力を算出する。伝送回路部３３４は、例えば、ＲＳ４８５などに準拠した２線式シリアル通信回路を有し、接続される通信線を介して相互に通信可能な監視装置４に電力演算値を送信する。
　次に、本実施の形態１に係る電力計測器３に備わる電流検出部３１の回路構成に関して図３を参照して説明する。電流検出部３１は、直列に接続された抵抗値の異なる２種類の負担抵抗３１１ａ，３１１ｂを備える。例えば、負担抵抗３１１ａは２．０Ωの抵抗、負担抵抗３１１ｂは１ｍΩのシャント抵抗である。なお、シャント抵抗は、大電流が流れる回路の電流計測用に作られた抵抗値が小さく高精度な抵抗器である。本実施の形態では電流検出部３１が２種類の変流器２ａ，２ｂに接続できる２種類の負担抵抗を備えることを説明したが、３種類以上の出力の異なる変流器に接続できる３種類以上の負担抵抗を備えても良い。
　また、負担抵抗３１１ａ，３１１ｂに接続される基準電位側の信号線は、０Ｖのグランド（ＧＮＤ）３１４に接続され、負担抵抗３１１ａの一端が加算回路３１３側に接続される。このように、電流検出部３１は、回路に挿入された負担抵抗３１１ａ，３１１ｂの最両端の電圧を測定して電流値を取得する信号処理回路を有する。
　電力計測器３は、それぞれが負担抵抗３１１ａ，３１１ｂの端部に接続された接続端子３ａ~３ｃを備える。変流器２ａ，２ｂは上述のように２種類の出力の異なるものであり、これら変流器２ａ，２ｂは、その種類に応じて、直列に接続された負担抵抗３１１ａ，３１１ｂの最両端、又は直列に接続された負担抵抗３１１ａ，３１１ｂの一端部と負担抵抗３１１ａ，３１１ｂとの間の所定位置に接続される。
　すなわち、比較的大きな電流を出力する対５ＡＣＴ２ａからの信号線は、回路に挿入される負担抵抗を小さくする必要があるため接続端子３ｂ，３ｃに接続される。一方、比較的小さな電流を出力する小型ＣＴ２ｂからの信号線は、変流器２ａ，２ｂと接続される回路に挿入される負担抵抗の抵抗値を大きくする必要があるため、接続端子３ａ，３ｃに接続される。このように、接続端子３ｃは、変流器２ａ，２ｂの出力の基準となる信号線を接続する共通の端子、接続端子３ａは、変流器２ｂの他の信号線を接続する個別の端子、接続端子３ｂは、変流器２ａの他の信号線を接続する個別の端子となる。
　以上のように、本実施の形態１に係る電力計測器３では、種類の異なる変流器２ａ，２ｂの信号線の接続位置を、直列に接続された負担抵抗３１１ａ，３１１ｂの抵抗値に応じて設けられた接続端子３ａ~３ｃを変更することで調節できる。このため、電力計測器３では、回路切替を行う手間を要せず、出力の異なる変流器２ａ，２ｂを同一の電流検出部３１に接続可能とし、分電盤１内における回路の電力を計測でき、電流計測器３の小型化や低コスト化を実現できる。
　さらに、電力計測器３に通信接続された監視装置４により、負荷５の消費電力を「見える化」して、どの負荷５の電力を削減すべきかを視覚的に理解できるなど、より効果的な省エネルギーを実現できる。
　なお、図３に示すように、複数の負担抵抗３１１ａ，３１１ｂの直列に接続する順序は、基準電位３１４側の負担抵抗３１１ｂの抵抗値を低くする。これにより、基準電位３１４に対して電圧降下を低く抑えることができ、電力計測器３の回路を安定に動作でき、ノイズ等の影響を低減できる。
　（第１の変形例）
　本実施の形態１の第１の変形例について、図４を参照して説明する。本変形例では、電流検出部３１は、直列に接続された負担抵抗３１１ａ，３１１ｂのうち、負担抵抗３１１ａには導通用のリレー３１５が並列に接続される。また、接続端子３ａ，３ｃは、直列に接続された負担抵抗３１１ａ，３１１ｂの最両端にそれぞれ接続され、出力の異なる変流器２ａ，２ｂは、同じ接続端子３ａ，３ｃに接続される。なお、本変形例では、上記実施の形態１とは異なり、直列に接続された負担抵抗３１１ａ，３１１ｂのうち、基準電位３１４側に抵抗値の大きい負担抵抗３１１ａが配置される。
　次に、本変形例に係る電力計測器３の動作に関して説明する。対５ＡＣＴ２ａが接続端子３ａ，３ｃに接続される場合には、リレー３１５が閉状態に、例えば、後述のスイッチ部１１（図１２参照）によって手動制御され、対５ＡＣＴ２ａからの出力電流がシャント抵抗３１１ｂのみを通過する回路となる。一方、小型ＣＴ２ｂが接続端子３ａ，３ｃに接続される場合には、リレー３１５が開状態に手動制御され、小型ＣＴ２ｂからの出力電流がシャント抵抗３１１ｂ及び負担抵抗３１１ａを通過する回路となる。このため、本変形例に係る電力計測器３では、１ａ接点構成を有するリレー３１５を用いた低コストの構成で、出力の異なる変流器２ａ，２ｂを同一の電流検出部３１に接続可能とする。
　（第２の変形例）
　本実施の形態１の第２の変形例について、図５を参照して説明する。本実施の形態１の第２の変形例は実施の形態１と類似しているが、例えば、手動制御されるマルチプレクサ３１６が負担抵抗３１１ａの両端に追加されたところが異なる。本変形例２において電流検出部３１は、直列に接続された２種類の負担抵抗３１１ａ，３１１ｂの端部の所定位置（つまり、負担抵抗３１１ａの両端）に接続され、接続端子３ａ~３ｃから電力演算部３３に繋がる信号線の経路を選択する回路切替機能を有したマルチプレクサ３１６をさらに備える。このため、本変形例２に係る電力計測器３では、回路切替器に信号用のマルチプレクサ３１６を使用し、出力の異なる変流器２ａ，２ｂを同一の電流検出部３１に接続可能として分電盤内における回路の電力を計測できる。従って、電力計測器３の小型化や低コスト化を実現できる。
　（第３の変形例）
　本実施の形態１の第３の変形例について、図６を参照して説明する。本変形例３において電流検出部３１は、上記変形例２の構成に加えて、信号の増幅率を可変可能なプログラマブルゲインアンプ３１７をさらに備える。このプログラマブルゲインアンプ３１７は、アナログスイッチ等を用いて増幅率を外部から設定できる増幅回路となる。変流器２ａ，２ｂの出力は、定格電流により異なるが、本変形例３に係る電力計測器３では、プログラマブルゲインアンプ３１７を用いてゲイン切替え、最適な信号で加算回路３１３に信号を入力し、電力演算部３３で電力演算することが可能となる。
　（第４の変形例）
　本実施の形態１の第４の変形例について、図７を参照して説明する。本変形例４では、負担抵抗３１１ａ，３１１ｂに接続される基準電位側の信号線を、グランドである０Ｖ以外の所定の基準電位Ｖｒｅｆに接続する。この構成により、電力演算部３３のＡＤ変換部３３２に信号を入力する際、基準電位Ｖｒｅｆを印加でき、負担抵抗３１１ａ，３１１ｂで得られる信号に対する加算回路３１３の構成が不要となり、信号線を直接、電力演算部３３のＡＤ変換部３３２に接続できる。従って、本変形例では、電流検出部３１の回路構成を簡略化して低コスト化を図り、且つ出力の異なる変流器２ａ，２ｂを同一の電流検出部３１に接続可能とし、分電盤内における回路の電力を計測できる。また、電力計測器３の小型化や低コスト化を実現できる。
　（実施の形態２）
　本発明の実施の形態２に係る電力計測器について、図８を参照して説明する。なお、上記実施の形態１と同様の構成には同一の符号を付し、その詳細な説明は省略する（以下同じ）。
　電流検出部３１は、それぞれの一端部に接続されて並列に配置された２つの負担抵抗３１１ａ，３１１ｂと、負担抵抗３１１ａ，３１１ｂの他端部に接続されて変流器２ａ，２ｂの出力の電流経路を負担抵抗３１１ａ，３１１ｂのいずれかとする回路構成を有する回路切替器（１ｃ接点構成の接触抵抗の低い有接点リレー）３１８と、加算回路３１３とを備える。変流器２ａ，２ｂの信号線は、その種類によらず、並列に接続された負担抵抗３１１ａ，３１１ｂの両端側に接続された接続端子３ａ，３ｃと接続される。
　このため、本実施の形態２では、変流器２ａ，２ｂのいずれを電力計測器３に接続しても、回路切替器３１８により、変流器２ａ，２ｂの種類に応じた適切な負担抵抗３１１ａ，３１１ｂに接続できる。従って、電流検出信号の信号レベルを所定のレベルまで上げて、Ｓ／Ｎ比を向上させて精度のよい電力の計測が可能となる。
　（実施の形態３）
　本発明の実施の形態３に係る電力計測器について、図９を参照して説明する。本実施の形態３では、電流検出部３１の直列に接続された負担抵抗３１１ａ，３１１ｂ間に設けられる接続端子３ｂ，３ｄは、異なる種類の変流器２ａ，２ｂで共用とせず、その種類ごとに個別に設けられる。すなわち、図９に示すように、小型ＣＴ２ｂの信号線と接続されるのは接続端子３ａ，３ｄであり、対５ＡＣＴ２ａの信号線と接続されるのは接続端子３ｂ，３ｃとなる。この構成により、出力の異なる変流器２ａ，２ｂを同一の電流検出部３１に接続可能とし、分電盤内の回路の電力を計測できると共に、変流器２ａ，２ｂからの電流の流れる経路を完全に別々にでき、より高精度な電力計測が可能となる。
　（第１の変形例）
　本実施の形態３の第１の変形例について、図１０を参照して説明する。本変形例では、抵抗値のより大きな負担抵抗３１１ａの両端に接続される接続端子３ａ，３ｄは、専用のコネクタ端子（プラグ）９ａ以外は接続できない構造、すなわちコネクタ端子９ａの形状と嵌合するコネクタ形状３ｅとなる。
　この構成により、本変形例では、対５ＡＣＴ２ａが、抵抗値の大きな負担抵抗３１１ａに接続され、負担抵抗３１１ａが焼損して誤結線による事故を未然に防ぐことが可能となる。また、コネクタ端子９ａの構造とすることで変流器２ａ，２ｂ及び電力計測器３間の施工性をよくすることができる。
　（第２の変形例）
　本実施の形態３の第２の変形例について、図１１を参照して説明する。本変形例では、コネクタ端子（プラグ）９ｂは、２以上の変流器（本図では小型ＣＴ２ｂの２台）からの信号線が接続可能な構造を有している。一方、電力計測器３には、その側面などにおいて、このコネクタ端子９ｂと嵌合する形状を有するコネクタ接続端子３ｆが形成される。この構成により、上記変形例１の効果に加えて、三相３線式を用いる電線などからの電力計測など、Ｒ／Ｓ／Ｔ相に取付けられる複数個の変流器２ａ，２ｂがセットとなった回路計測において、誤結線を未然に防止できる。
　（実施の形態４）
　本発明の実施の形態４に係る電力計測器について、図１２を参照して説明する。図１２（ａ）は本発明の実施の形態４に係る電力計測器の正面図、図１２（ｂ）は同電力計測器の下面図、図１２（ｃ）は同電力計測器の上面図である。本実施の形態４に係る電力計測器３は、表示部１０、スイッチ部１１、電圧入力端子１２、通信端子１３、対５ＡＣＴ接続端子１４、及び小型ＣＴ接続端子１５を備える。
　表示部１０は、各回路における電力計測結果を表示する液晶パネルなどである。スイッチ部１１は、変流器２ａ，２ｂの種類の設定、表示部１０の表示設定を行うための操作キーである。電圧入力端子１２は、電線と接続されて電圧極Ｓと電圧極Ｔの相関電圧などを検出するための入力端子である。通信端子１３は、監視装置４と接続され、ＲＳ−４８５通信などで用いる通信線を接続するネジ端子である。対５ＡＣＴ接続端子１４は、対５ＡＣＴ２ａからの信号線を接続するネジ端子である。小型ＣＴ接続端子１５は、小型ＣＴ２ｂからのコネクタ端子９ａが挿し込まれる差込口となるコネクタ端子である。
　主幹回路及び当該主幹回路から分岐した複数の分岐回路からなる回路は、左右方向に隣接して電力計測器３の側面に配置される。そして、点線Ｌの領域に示すように、接続端子１４、１５は、前後方向に、直線状に配置される。この配置構成により、本実施の形態４に係る電力計測器３では、同じ回路に、複数の変流器２ａ，２ｂを同時に接続することを視覚的に防止できる。また、本発明の実施の形態では上述の接続端子が電力計測器３の側面に配置されるものであると説明したが、上面、下面、または正面に配置されても良い。
　（第１の変形例）
　本実施の形態４の第１の変形例について、図１３を参照して説明する。電力計測器３は、上記図１２に示すように、出力の大きな変流器２ａの信号線を接続するネジ端子である複数の接続端子１４、及び出力の小さな変流器２ｂの信号線を接続するコネクタ端子である複数の接続端子１５を備えている。そして、本変形例では、図１３（ａ）~（ｃ）に示すように、変流器２ａ，２ｂの信号線に接続されるプラグ１６は、コネクタ端子１６ｂが接続端子１５に挿入されると、ネジ端子である接続端子１４を塞ぐ突起部１６ａを有している。また、本実施の形態ではプラグ１６が突起部１６ａを有する構造として説明したが、接続端子を塞ぐことができれば、プラグ１６の構造はどのような構造であっても構わない。
　この構成により、同じ回路において、同時に２種類の変流器２ａ，２ｂが接続されることがなくなり、小型ＣＴ２ｂと対５ＡＣＴ２ａの同時接続による誤接続を防止できる。なお、プラグ１６の構造を、ネジ端子である接続端子１４を接続するとコネクタ端子である接続端子１５を塞ぐ構造とすることも考え得る。
　（第２の変形例）
　本実施の形態４の第２の変形例について、図１４を参照して説明する。本変形例では、点線Ｌ２の領域で示すように、電力計測器３の接続端子は、変流器２ａ，２ｂで計測される一部の回路において、ネジ端子の接続端子１４のみの構成となる。
　これは、分電盤内の主幹回路と分岐回路を計測する際、主幹回路は定格電流が大きくなるため対５ＡＣＴ２ａで、分岐回路は定格電流が比較的低くなるため小型ＣＴ２ｂを選定し計測する。従って、電力計測器３では、所定の回路は５ＡＣＴ２ａの接続端子１４のみ、所定の回路は小型ＣＴ２ｂの接続端子１５又は対５ＡＣＴ２ａの接続端子１４の選択式とするため、全ての回路を選択式の接続端子１４，１５の構造にするよりも低コストで構成できる。なお、図示はしていないが、一部の計測回路を小型ＣＴ２ｂ用の接続端子１５のみの構成とすることも考え得る。
　そして、上記各実施の形態に係る電力計測器３は、主幹回路及び分岐回路からなる回路の電力を計測するための接続端子の組を複数備えて、多回路の電力計測を可能とする。これは、主幹回路から分岐回路までを計測する際、複数の定格電流の計測が必要であり、多回路の電力計測を可能とすることにより、電力計測器３の小型化を図れるためである。
　なお、本発明は、上記実施の形態の構成に限られず、発明の趣旨を変更しない範囲で種々の変形が可能である。例えば、変流器２ａ，２ｂや負担抵抗３１１ａ，３１１ｂの種類は２種類に限定されるものではなく、少なくとも２種類以上であればよい。また、変流器の種類は対５ＡＣＴや小型ＣＴに限定されるものではなく、定格電流５０Ａ，２５０Ａ，６００Ａなどの変流器を使用することもできる。さらに、様々な種類の異なる変流器は、その種類に応じて、直列に接続された複数の負担抵抗の所定位置、又は当該所定位置と異なる別の所定位置に接続されればよく、負担抵抗の最両端の位置に限定されるものではない。
　ここで、上述のすべての実施の形態及びその変形例は互いに組み合わせて行うことができる。
　以上、本発明の好ましい実施の形態が説明されているが、本発明はこれらの特定の実施の形態に限られるものではなく、請求範囲の範疇から離脱しない多様な変更及び変形が可能であり、それも本発明の範疇内に属する。 Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The same or similar parts throughout the drawings are denoted by the same reference numerals, and the description thereof is omitted.
(Embodiment 1)
A power meter according to Embodiment 1 of the present invention will be described with reference to the drawings. As shown in FIG. 1, the power measurement system S includes a distribution board 1, different types of current transformers 2 a and 2 b, a power meter 3, a monitoring device 4, a load 5, and breakers 6 a, 6 b and 6 c. The power measurement system S monitors the power consumption of various loads 5 such as a lighting fixture or a personal computer that receives power supply from the distribution board 1 in an office building or a general house, for example. Here, FIG. 1 shows a configuration for measuring power from an electric wire using a three-phase three-wire system. For example, current transformers 2a and 2b are attached to the R / T phase and current values are measured. Is shown.
The distribution board 1 includes a main circuit that receives commercial power supplied from outside to the building or house on the primary side via the electric wires 7, and a plurality of electric circuits that are installed on the electric circuit branched from the secondary side of the main circuit. And a branch circuit. Each branch circuit is connected to various loads 5 such as an air-conditioning device and an IH (Induction Heating) device in addition to a lighting fixture and a personal computer. Moreover, the breaker 6a is a main breaker connected to the electric wire 7 of the main circuit, and the breaker 6b is a branch breaker disposed in a plurality of branch circuits branched from the main circuit.
Different types of current transformers 2a and 2b reduce the current of each circuit at a constant rate and supply it to the power meter 3 via the signal line 8 which is a dedicated cable. For example, if the current transformer 2a is a 400 / 5A type penetration type, the number of turns of the coil is configured so that when a current of 400A flows through the electric wire 7 passing through the center portion, 5A flows through the signal line 8 on the output side. ing.
The current transformer 2a is installed to periodically measure the main current flowing through the main circuit through which a relatively large current flows. In the figure, the current transformer 2a is passed through each electric wire of the main circuit wiring to measure power. The device 3 is connected to the signal line 8. The current transformer 2b is installed in order to periodically measure the branch current flowing through each branch circuit through which a relatively small current flows for each branch circuit, and is passed through a predetermined position of the electric wire of the branch circuit. Connected by signal line 8. The current transformers 2a and 2b can be easily attached to the main circuit 7 and the branch circuit wires 7 by a split type or the like, and by using a dedicated cable as the signal line 8, erroneous connection can be prevented.
The power measuring instrument 3 is connected to the current transformers 2a and 2b, and has a burden resistor to be inserted into a circuit connected to the current transformers 2a and 2b. The power measuring instrument 3 supplies the power of the circuit in which the current transformers 2a and 2b are installed. measure. The power meter 3 outputs the calculation result to the monitoring device 4 via the communication line. The power measuring instrument 3 has a size of 10 × 10 cm, for example, and is installed at a predetermined location in the distribution board 1.
The monitoring device 4 is a dedicated personal computer or the like having a monitor, and is a monitoring unit that manages and displays energization information of each branch circuit. The monitoring device 4 is connected to the power meter 3 via RS-485 communication or the like, collects data related to the power usage of each load 5, and displays a graph or the like for data analysis. The monitoring device 4 automatically records, for example, data relating to power usage every hour or every day, performs collective energy management via a network connected to the power meter 3, and “visible” the efficient power usage is seen. Realization.
The load 5 is various electric devices such as an air conditioner and an IH device, in addition to a lighting device and a personal computer connected to the branch circuit.
Next, the functional configuration of the power meter 3 according to the first embodiment will be described with reference to FIG. FIG. 2 shows a configuration for power measurement for one current transformer 2a or 2b for convenience. The power meter 3 includes a current detector 31 that detects a current signal from signals from the current transformers 2a and 2b, a voltage detector 32 that detects a voltage signal of the circuit, and a current and voltage detector 32 in the current detector 31. A power calculation unit 33 that calculates power based on each voltage signal is provided.
The current detection unit 31 includes a burden resistor 311 inserted in a circuit connected to the current transformers 2a and 2b, a filter 312 that passes a signal in a predetermined frequency band, and a voltage value of a current signal that has passed through the filter 312 to a predetermined value. An adder circuit 313 is provided.
The voltage detector 32 is connected to the electric wire 7 via a breaker 6c shown in FIG. 1 and the like, and includes a voltage step-down circuit 321, a filter 322, and an adder circuit 323. The voltage step-down circuit 321 steps down the voltage, the filter 322 passes a voltage signal in a predetermined frequency band, and the addition circuit 323 applies an appropriate bias to the voltage signal so that the voltage waveform is in the range of, for example, 0 to 5V. Call.
Based on the current measured by the current detector 31 and the voltage detected by the voltage detector 32, the power calculator 33 supplies the load 5 connected to the electric wire 7 to which the current transformers 2a and 2b are attached. It is a microcomputer that calculates the electric power. The power calculation unit 33 includes A / D conversion units 331 and 332, a multiplication unit 333, and a transmission circuit unit 334.
The A / D converter 331 converts the analog signal received from the voltage detector 32 into a digital signal. The A / D converter 332 converts the analog signal received from the current detector 31 into a digital signal. The multiplier 333 is a circuit that multiplies the signals output from the A / D converters 331 and 332, that is, calculates power. The transmission circuit unit 334 includes, for example, a two-wire serial communication circuit compliant with RS485 and transmits a power calculation value to the monitoring device 4 that can communicate with each other via a connected communication line.
Next, the circuit configuration of the current detection unit 31 provided in the power meter 3 according to the first embodiment will be described with reference to FIG. The current detection unit 31 includes two types of burden resistors 311a and 311b connected in series and having different resistance values. For example, the burden resistor 311a is a 2.0Ω resistor, and the burden resistor 311b is a 1 mΩ shunt resistor. Note that the shunt resistor is a highly accurate resistor with a small resistance value made for current measurement of a circuit through which a large current flows. In the present embodiment, it has been described that the current detection unit 31 includes two types of burden resistors that can be connected to the two types of current transformers 2a and 2b, but three types that can be connected to three or more types of current transformers with different outputs. You may provide the above burden resistance.
Further, the signal line on the reference potential side connected to the burden resistors 311a and 311b is connected to the 0V ground (GND) 314, and one end of the burden resistor 311a is connected to the adder circuit 313 side. As described above, the current detection unit 31 includes a signal processing circuit that measures the voltages at both ends of the load resistors 311a and 311b inserted in the circuit and obtains a current value.
The power measuring instrument 3 includes connection terminals 3a to 3c that are connected to the ends of the load resistors 311a and 311b, respectively. The current transformers 2a and 2b have two different outputs as described above, and the current transformers 2a and 2b are arranged at the extreme ends of the load resistors 311a and 311b connected in series according to the type. Or it connects to the predetermined position between the one end part of burden resistance 311a, 311b connected in series and burden resistance 311a, 311b.
That is, the signal line from the pair 5ACT 2a that outputs a relatively large current is connected to the connection terminals 3b and 3c because it is necessary to reduce the burden resistance inserted in the circuit. On the other hand, since the signal line from the small CT 2b that outputs a relatively small current needs to increase the resistance value of the burden resistance inserted in the circuit connected to the current transformers 2a and 2b, the connection terminals 3a and 3c Connected to. As described above, the connection terminal 3c is a common terminal for connecting the signal lines serving as the reference of the outputs of the current transformers 2a and 2b, and the connection terminal 3a is an individual terminal for connecting other signal lines of the current transformer 2b. The connection terminal 3b is an individual terminal for connecting the other signal line of the current transformer 2a.
As described above, in the power measuring instrument 3 according to the first embodiment, the connection positions of the signal lines of the different types of current transformers 2a and 2b are set according to the resistance values of the load resistors 311a and 311b connected in series. It can be adjusted by changing the connection terminals 3a to 3c provided. For this reason, in the electric power measuring device 3, the effort which switches a circuit is not required, the current transformers 2a and 2b from which an output differs can be connected to the same electric current detection part 31, and the electric power of the circuit in the distribution board 1 is made. The current measuring device 3 can be reduced in size and cost.
Furthermore, the monitoring device 4 connected to the power meter 3 can “visualize” the power consumption of the load 5 and visually understand which load 5 the power should be reduced. Energy saving can be realized.
As shown in FIG. 3, the order of connecting the plurality of burden resistors 311a and 311b in series lowers the resistance value of the burden resistor 311b on the reference potential 314 side. Thereby, a voltage drop can be suppressed low with respect to the reference potential 314, the circuit of the power meter 3 can be stably operated, and the influence of noise and the like can be reduced.
(First modification)
A first modification of the first embodiment will be described with reference to FIG. In the present modification, in the current detection unit 31, among the load resistors 311a and 311b connected in series, a conduction relay 315 is connected in parallel to the load resistor 311a. The connection terminals 3a and 3c are respectively connected to the extreme ends of the load resistors 311a and 311b connected in series, and the current transformers 2a and 2b having different outputs are connected to the same connection terminals 3a and 3c. In this modification, unlike the first embodiment, among the load resistors 311a and 311b connected in series, a load resistor 311a having a large resistance value is arranged on the reference potential 314 side.
Next, the operation of the power meter 3 according to this modification will be described. When the pair 5ACT 2a is connected to the connection terminals 3a, 3c, the relay 315 is closed, for example, manually controlled by a switch unit 11 (see FIG. 12) described later, and the output current from the pair 5ACT 2a is shunt resistance 311b. It becomes a circuit that passes only. On the other hand, when the small CT 2b is connected to the connection terminals 3a and 3c, the relay 315 is manually controlled to be in an open state, and the output current from the small CT 2b passes through the shunt resistor 311b and the burden resistor 311a. For this reason, in the power meter 3 according to this modification, the current transformers 2a and 2b having different outputs can be connected to the same current detection unit 31 with a low-cost configuration using the relay 315 having the 1a contact configuration. To do.
(Second modification)
A second modification of the first embodiment will be described with reference to FIG. The second modification of the first embodiment is similar to the first embodiment except that, for example, a manually controlled multiplexer 316 is added to both ends of the burden resistor 311a. In the second modification, the current detection unit 31 is connected to predetermined positions (that is, both ends of the load resistor 311a) at the ends of the two types of load resistors 311a and 311b connected in series, and power is supplied from the connection terminals 3a to 3c. A multiplexer 316 having a circuit switching function for selecting a path of a signal line connected to the calculation unit 33 is further provided. For this reason, in the power measuring instrument 3 according to the second modification, the signal multiplexer 316 is used as the circuit switch, and the current transformers 2a and 2b having different outputs can be connected to the same current detection unit 31. The power of the circuit in the panel can be measured. Therefore, it is possible to reduce the size and cost of the power measuring instrument 3.
(Third Modification)
A third modification of the first embodiment will be described with reference to FIG. In the third modification, in addition to the configuration of the second modification, the current detection unit 31 further includes a programmable gain amplifier 317 capable of changing a signal amplification factor. The programmable gain amplifier 317 is an amplifier circuit that can set the amplification factor from the outside using an analog switch or the like. The outputs of the current transformers 2a and 2b differ depending on the rated current. However, in the power measuring instrument 3 according to the third modification, the gain is switched using the programmable gain amplifier 317, and a signal is input to the adder circuit 313 with an optimum signal. The power calculation unit 33 can calculate the power.
(Fourth modification)
A fourth modification of the first embodiment will be described with reference to FIG. In the fourth modification, a signal line on the reference potential side connected to the burden resistors 311a and 311b is connected to a predetermined reference potential Vref other than 0V that is a ground. With this configuration, when a signal is input to the AD conversion unit 332 of the power calculation unit 33, the reference potential Vref can be applied, the configuration of the addition circuit 313 for the signals obtained by the burden resistors 311a and 311b is not required, and the signal line is directly connected. The AD converter 332 of the power calculator 33 can be connected. Therefore, in this modification, the circuit configuration of the current detection unit 31 is simplified to reduce the cost, and the current transformers 2a and 2b having different outputs can be connected to the same current detection unit 31. The power of the circuit can be measured. Further, the power meter 3 can be reduced in size and cost.
(Embodiment 2)
A power meter according to Embodiment 2 of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the structure similar to the said Embodiment 1, and the detailed description is abbreviate | omitted (hereinafter the same).
The current detector 31 is connected to one end of each of the two load resistors 311a and 311b arranged in parallel, and is connected to the other end of the load resistors 311a and 311b to output the current transformers 2a and 2b. A circuit switcher (a contact relay with a low contact resistance having a 1c contact configuration) 318 having a circuit configuration in which the current path is one of the burden resistors 311a and 311b, and an adder circuit 313 are provided. The signal lines of the current transformers 2a and 2b are connected to the connection terminals 3a and 3c connected to both ends of the load resistors 311a and 311b connected in parallel, regardless of the type.
For this reason, in this Embodiment 2, even if any of current transformer 2a, 2b is connected to the electric power measuring device 3, the appropriate load resistance according to the kind of current transformer 2a, 2b by the circuit switch 318 is shown. 311a and 311b can be connected. Therefore, the signal level of the current detection signal is raised to a predetermined level, the S / N ratio is improved, and the power can be accurately measured.
(Embodiment 3)
A power meter according to Embodiment 3 of the present invention will be described with reference to FIG. In the third embodiment, the connection terminals 3b and 3d provided between the load resistors 311a and 311b connected in series of the current detection unit 31 are not shared by the different types of current transformers 2a and 2b. Provided separately. That is, as shown in FIG. 9, the connection terminals 3a and 3d are connected to the signal line of the small CT 2b, and the connection terminals 3b and 3c are connected to the signal line of the pair 5ACT 2a. With this configuration, the current transformers 2a and 2b having different outputs can be connected to the same current detection unit 31, the power of the circuit in the distribution board can be measured, and the current flow path from the current transformers 2a and 2b flows. Can be completely separated, and more accurate power measurement becomes possible.
(First modification)
A first modification of the third embodiment will be described with reference to FIG. In this modification, the connection terminals 3a and 3d connected to both ends of the burden resistor 311a having a larger resistance value are fitted to a structure in which only the dedicated connector terminal (plug) 9a can be connected, that is, the shape of the connector terminal 9a. The connector shape is 3e.
With this configuration, in this modified example, the pair 5ACT 2a is connected to the burden resistor 311a having a large resistance value, and the burden resistor 311a is burned out, thereby preventing an accident due to erroneous connection. Moreover, the construction between the current transformers 2a and 2b and the power measuring device 3 can be improved by adopting the structure of the connector terminal 9a.
(Second modification)
A second modification of the third embodiment will be described with reference to FIG. In this modification, the connector terminal (plug) 9b has a structure to which signal lines from two or more current transformers (two small CTs 2b in this figure) can be connected. On the other hand, the power measuring instrument 3 is formed with a connector connecting terminal 3f having a shape that fits with the connector terminal 9b on the side surface thereof. With this configuration, in addition to the effect of the first modification, a plurality of current transformers 2a and 2b attached to the R / S / T phase, such as power measurement from a wire using a three-phase three-wire system, are set. In the circuit measurement, it is possible to prevent erroneous connection.
(Embodiment 4)
A power meter according to Embodiment 4 of the present invention will be described with reference to FIG. 12 (a) is a front view of a power meter according to Embodiment 4 of the present invention, FIG. 12 (b) is a bottom view of the power meter, and FIG. 12 (c) is a top view of the power meter. is there. The power meter 3 according to the fourth embodiment includes a display unit 10, a switch unit 11, a voltage input terminal 12, a communication terminal 13, a pair 5ACT connection terminal 14, and a small CT connection terminal 15.
The display unit 10 is a liquid crystal panel or the like that displays a power measurement result in each circuit. The switch unit 11 is an operation key for setting the types of the current transformers 2 a and 2 b and setting the display of the display unit 10. The voltage input terminal 12 is an input terminal that is connected to an electric wire and detects a correlation voltage between the voltage electrode S and the voltage electrode T. The communication terminal 13 is a screw terminal that is connected to the monitoring device 4 and connects a communication line used for RS-485 communication or the like. The pair 5ACT connection terminal 14 is a screw terminal for connecting a signal line from the pair 5ACT2a. The small CT connection terminal 15 is a connector terminal serving as an insertion port into which the connector terminal 9a from the small CT 2b is inserted.
A circuit composed of a main circuit and a plurality of branch circuits branched from the main circuit is arranged on the side surface of the power meter 3 adjacent in the left-right direction. And as shown to the area | region of the dotted line L, the connection terminals 14 and 15 are arrange | positioned at linear form in the front-back direction. With this arrangement configuration, the power meter 3 according to the fourth embodiment can visually prevent a plurality of current transformers 2a and 2b from being connected to the same circuit at the same time. Moreover, although the above-mentioned connection terminal demonstrated that it was arrange | positioned at the side surface of the electric power measuring device 3 in embodiment of this invention, you may arrange | position to an upper surface, a lower surface, or a front.
(First modification)
A first modification of the fourth embodiment will be described with reference to FIG. As shown in FIG. 12, the power meter 3 connects a plurality of connection terminals 14 that are screw terminals for connecting a signal line of a current transformer 2a having a large output and a signal line of a current transformer 2b having a small output. A plurality of connection terminals 15 that are connector terminals are provided. In this modification, as shown in FIGS. 13A to 13C, when the plug 16 connected to the signal line of the current transformers 2a and 2b is inserted into the connection terminal 15, the connector terminal 16b is inserted. And a projection 16a that closes the connection terminal 14 that is a screw terminal. In the present embodiment, the plug 16 is described as having a protrusion 16a. However, the plug 16 may have any structure as long as the connection terminal can be blocked.
With this configuration, two types of current transformers 2a and 2b are not simultaneously connected in the same circuit, and erroneous connection due to simultaneous connection of the small CT 2b and the pair 5ACT 2a can be prevented. In addition, it can also be considered that the structure of the plug 16 is a structure that closes the connection terminal 15 that is a connector terminal when the connection terminal 14 that is a screw terminal is connected.
(Second modification)
A second modification of the fourth embodiment will be described with reference to FIG. In this modification, as shown by the area of the dotted line L2, the connection terminal of the power measuring instrument 3 has only the connection terminal 14 of the screw terminal in some circuits measured by the current transformers 2a and 2b. .
This is because when the main circuit and the branch circuit in the distribution board are measured, the main circuit has a larger rated current, so it is 5 ACT2a, and the branch circuit has a relatively low rated current, so a small CT 2b is selected and measured. Therefore, in the power meter 3, since the predetermined circuit is a selection formula of only the connection terminal 14 of the 5ACT2a and the predetermined circuit is a selection formula of the connection terminal 15 of the small CT2b or the connection terminal 14 of the pair 5ACT2a, all the circuits are selective formulas. It can be configured at a lower cost than the structure of the connection terminals 14 and 15. Although not shown, it is also conceivable that a part of the measurement circuit has only the connection terminal 15 for the small CT 2b.
The power measuring device 3 according to each of the above embodiments includes a plurality of connection terminal sets for measuring the power of a circuit composed of a main circuit and a branch circuit, and enables multi-circuit power measurement. This is because, when measuring from the main circuit to the branch circuit, it is necessary to measure a plurality of rated currents, and the power meter 3 can be miniaturized by enabling multi-circuit power measurement.
The present invention is not limited to the configuration of the embodiment described above, and various modifications can be made without departing from the spirit of the invention. For example, the types of current transformers 2a and 2b and burden resistors 311a and 311b are not limited to two types, and may be at least two types. Moreover, the type of current transformer is not limited to 5 ACT or small CT, and current transformers with rated currents of 50A, 250A, 600A can be used. Furthermore, various types of different current transformers may be connected to a predetermined position of a plurality of burden resistors connected in series or another predetermined position different from the predetermined position, depending on the type. It is not limited to the positions at the extreme ends.
Here, all of the above-described embodiments and their modifications can be combined with each other.
The preferred embodiments of the present invention have been described above, but the present invention is not limited to these specific embodiments, and various changes and modifications can be made without departing from the scope of the claims. It is also within the scope of the present invention.

Claims (11)

  1. 　回路から電圧信号を検出する電圧検出部と、前記回路に取り付けられた変流器からの出力に基づいて電流信号を検出する電流検出部と、前記電圧検出部及び電流検出部で検出される電圧信号及び電流信号に基づいて電力演算する電力演算部と、を備える電力計測器において、
    　前記電流検出部は、少なくとも２種類以上の負担抵抗と、前記変流器からの出力を信号処理する信号処理回路とを備え、
    　前記電流検出部には、少なくとも２種類以上の出力の異なる変流器が接続できることを特徴とする電力計測器。     A voltage detector for detecting a voltage signal from the circuit; a current detector for detecting a current signal based on an output from a current transformer attached to the circuit; and a voltage detected by the voltage detector and the current detector. In a power measuring instrument comprising a power calculation unit that calculates power based on a signal and a current signal,
    The current detection unit includes at least two types of burden resistors and a signal processing circuit that performs signal processing on an output from the current transformer,
    The current detector can be connected to at least two types of current transformers having different outputs.
  2. 　前記電流検出部に備えられる２種類の負担抵抗は直列に接続され、
    　前記２種類の出力の異なる変流器はその種類に応じて前記直列に接続された負担抵抗の所定位置、又は前記所定位置と異なる別の所定位置に接続される、ことを特徴とする請求項１に記載の電力計測器。     Two types of burden resistors provided in the current detection unit are connected in series,
    The two types of current transformers having different outputs are connected to a predetermined position of the load resistor connected in series according to the type or another predetermined position different from the predetermined position. The power measuring instrument according to 1.
  3. 　前記電流検出部に備えられる２種類の負担抵抗は直列に接続され、
    　前記直列に接続された負担抵抗のうち少なくとも１つの負担抵抗には、導通用のリレーが並列に接続され、
    　前記変流器は前記直列に接続された負担抵抗の最両端に接続される、ことを特徴とする請求項１記載の電力計測器。     Two types of burden resistors provided in the current detection unit are connected in series,
    A relay for conduction is connected in parallel to at least one burden resistor among the burden resistors connected in series,
    The power measuring device according to claim 1, wherein the current transformer is connected to both ends of the burden resistor connected in series.
  4. 　前記電流検出部は、
    　前記直列接続された負担抵抗の一端部に接続されて前記２種類の出力の異なる変流器の出力の基準となる信号線が接続される共通の接続端子、及び前記所定位置及び前記別の所定位置に接続されて前記２種類の出力の異なる変流器の他の信号線が接続される個別の接続端子と、
    　前記個別の接続端子から前記電力演算部に繋がる前記信号線の経路を選択する回路切替機能を有したマルチプレクサと、をさらに備える、ことを特徴とする請求項２に記載の電力計測器。     The current detector is
    A common connection terminal connected to one end of the burden resistor connected in series and connected to a signal line serving as a reference for outputs of the two types of current transformers having different outputs, and the predetermined position and the other predetermined A separate connection terminal to which the other signal line of the current transformer of the two kinds of outputs connected to the position is connected;
    The power meter according to claim 2, further comprising: a multiplexer having a circuit switching function for selecting a path of the signal line connected to the power calculation unit from the individual connection terminal.
  5. 　前記電流検出部に備えられる２種類以上の負担抵抗は直列に接続され、
    　前記直列に接続された負担抵抗間には、前記異なる種類の変流器で共用とせず、変流器の種類ごとに個別に２つの個別接続端子が設けられる、ことを特徴とする請求項１に記載の電力計測器。     Two or more types of burden resistors provided in the current detection unit are connected in series,
    2. The load resistors connected in series are not shared by the different types of current transformers, but are provided with two individual connection terminals for each type of current transformer. The power meter described in 1.
  6. 　前記直列に接続された少なくとも２種類以上の負担抵抗のうち、抵抗値の最も大きな前記負担抵抗の両端にに接続された接続端子は、専用のコネクタ端子以外は接続できない構造を有する、ことを特徴とする請求項５記載の電力計測器。 Of the at least two types of burden resistors connected in series, the connection terminals connected to both ends of the burden resistor having the largest resistance value have a structure that cannot be connected except for a dedicated connector terminal. The power measuring instrument according to claim 5.
  7. 　前記回路は、主幹回路及び当該主幹回路から分岐した複数の分岐回路を含み、
    　前記電流検出部は、前記少なくとも２種類以上の出力の異なる変流器の信号線に接続する複数の接続端子をさらに備え、
    　前記複数の接続端子は、これら回路ごとに、隣接して配置される、ことを特徴とする請求項１に記載の電力計測器。     The circuit includes a main circuit and a plurality of branch circuits branched from the main circuit,
    The current detection unit further includes a plurality of connection terminals connected to the signal lines of the current transformers having different outputs of the at least two types.
    The power measuring device according to claim 1, wherein the plurality of connection terminals are arranged adjacent to each other for each of these circuits.
  8. 　前記複数の接続端子は、出力の大きな前記変流器の信号線に接続するネジ端子、及び出力の小さな前記変流器の信号線に接続するコネクタ端子を含み、
    　前記変流器の信号線と接続されたプラグは、前記ネジ端子又は前記コネクタ端子の一方との接続を行うと、他方の接続端子を塞ぐ構造を有する、ことを特徴とする請求項７記載の電力計測器。     The plurality of connection terminals include a screw terminal connected to a signal line of the current transformer having a large output, and a connector terminal connected to a signal line of the current transformer having a small output,
    The plug connected to the signal line of the current transformer has a structure that closes the other connection terminal when connected to one of the screw terminal or the connector terminal. Power meter.
  9. 　前記電流検出部に備えられる２種類以上の負担抵抗は直列に接続され、
    　前記直列に接続された負担抵抗に接続される基準電位側の信号線を、グランドである０Ｖ以外の所定の基準電位に接続する、ことを特徴とする請求項１乃至８のいずれか一項に記載の電力計測器。     Two or more types of burden resistors provided in the current detection unit are connected in series,
    9. The signal line on the reference potential side connected to the burden resistor connected in series is connected to a predetermined reference potential other than 0 V, which is a ground. 9. The power meter described.
  10. 　前記電力計測器は、多回路の電力計測が可能である、ことを特徴とする請求項１乃至８のいずれか一項に記載の電力計測器。 The power meter is capable of power measurement of multiple circuits, power meter according to any one of claims 1 to 8, characterized in that.
  11. 　前記電流検出部に備えられる２種類以上の負担抵抗は並列に接続され、
    　前記電流検出部は、前記並列に配置された負担抵抗の一端側に接続され、前記変流器の出力の電流経路を前記並列に接続された負担抵抗のいずれかの経路に切り替える回路切替器をさらに備え、
    　前記少なくとも２種類以上の出力の異なる変流器は、前記並列に接続された負担抵抗の両端側に接続される、ことを特徴とする請求項１に記載の電力計測器。     Two or more types of burden resistors provided in the current detection unit are connected in parallel,
    The current detection unit is connected to one end side of the burden resistor arranged in parallel, and a circuit switch that switches a current path of an output of the current transformer to any one of the burden resistors connected in parallel. In addition,
    2. The power meter according to claim 1, wherein the at least two types of current transformers having different outputs are connected to both ends of the burden resistor connected in parallel.
PCT/IB2012/001668 2011-08-31 2012-08-30 Electricity meter WO2013030655A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201280040798.1A CN103748475A (en) 2011-08-31 2012-08-30 Electricity meter

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2011-188529 2011-08-31
JP2011188529A JP2013050385A (en) 2011-08-31 2011-08-31 Power measuring instrument

Publications (2)

Publication Number Publication Date
WO2013030655A1 true WO2013030655A1 (en) 2013-03-07
WO2013030655A4 WO2013030655A4 (en) 2013-05-02

Family

ID=47755400

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2012/001668 WO2013030655A1 (en) 2011-08-31 2012-08-30 Electricity meter

Country Status (4)

Country Link
JP (1) JP2013050385A (en)
CN (1) CN103748475A (en)
TW (1) TWI458991B (en)
WO (1) WO2013030655A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105247375A (en) * 2013-06-13 2016-01-13 三菱电机株式会社 Power measurement device, determination method, and program

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015210232A (en) * 2014-04-30 2015-11-24 三菱電機株式会社 Electric power measurement device and electric power measurement system
CN106961155A (en) * 2017-03-30 2017-07-18 华映科技（集团）股份有限公司 A kind of intelligent power distribution access system for possessing electricity consumption data monitoring and security function
DE102017221173A1 (en) * 2017-11-27 2019-05-29 Siemens Aktiengesellschaft Current measuring device
JP7228799B2 (en) * 2018-03-13 2023-02-27 パナソニックＩｐマネジメント株式会社 measurement system
JP7001282B2 (en) * 2019-09-24 2022-02-03 株式会社Wave Energy Wattmeter relays, panels, and self-consumed power systems

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001208778A (en) * 2000-01-25 2001-08-03 Matsushita Electric Works Ltd Detected current combining apparatus and distribution board
JP2002075542A (en) * 2000-09-01 2002-03-15 Fci Japan Kk Polarity plug-in connector
JP3094528U (en) * 2002-12-06 2003-06-27 株式会社エム・システム技研 Multi-function signal converter
JP2005241305A (en) * 2004-02-24 2005-09-08 Matsushita Electric Works Ltd Phase adjustment circuit of watthour meter
JP2007205971A (en) * 2006-02-03 2007-08-16 Tohoku Electric Power Co Inc Current transformer, and instrument for measuring alternating current electric energy
JP2008203116A (en) * 2007-02-21 2008-09-04 Yokogawa Electric Corp Electrical quantity integrating device

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1069342A (en) * 1991-08-04 1993-02-24 郝天然 Pliers type electric power meter
JPH07229927A (en) * 1994-02-22 1995-08-29 Mitsubishi Electric Corp Current sensor
CN2192889Y (en) * 1994-05-27 1995-03-22 车仁生 Automatic copytype intelligence watt-hour meter for multi-house centralized measuring
JP2002027656A (en) * 2000-07-06 2002-01-25 Fuji Electric Co Ltd Overcurrent detecting method utilizing current transformer, and electronic circuit breaker using the same method
US7075288B2 (en) * 2003-07-01 2006-07-11 Itron, Inc. System and method for acquiring voltages and measuring voltage into and electrical service using a non-active current transformer
CN1570653A (en) * 2004-05-14 2005-01-26 杭州利尔达单片机技术有限公司 MSP430FE42x single phase multifunctional electric energy meter and metering method
CN1808507A (en) * 2005-01-17 2006-07-26 梅中健 Modular multiple-user KWH meter
EP1855122B1 (en) * 2005-01-31 2011-12-28 Toyotsugu Atoji Leak current breaker and method
UA93070C2 (en) * 2005-12-20 2011-01-10 Бредли Лейтон Росс Power distribution system having plurality of isolatable functional nodes
AU2009211720B2 (en) * 2008-02-06 2012-08-23 Mitsubishi Electric Corporation Power measuring system, measuring apparatus, load terminal, and device control system
US7719258B2 (en) * 2008-10-13 2010-05-18 National Taiwan University Of Science And Technology Method and apparatus for current measurement using hall sensors without iron cores
CN102023270A (en) * 2010-11-22 2011-04-20 李颖 Intelligent power network parameter sensor

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001208778A (en) * 2000-01-25 2001-08-03 Matsushita Electric Works Ltd Detected current combining apparatus and distribution board
JP2002075542A (en) * 2000-09-01 2002-03-15 Fci Japan Kk Polarity plug-in connector
JP3094528U (en) * 2002-12-06 2003-06-27 株式会社エム・システム技研 Multi-function signal converter
JP2005241305A (en) * 2004-02-24 2005-09-08 Matsushita Electric Works Ltd Phase adjustment circuit of watthour meter
JP2007205971A (en) * 2006-02-03 2007-08-16 Tohoku Electric Power Co Inc Current transformer, and instrument for measuring alternating current electric energy
JP2008203116A (en) * 2007-02-21 2008-09-04 Yokogawa Electric Corp Electrical quantity integrating device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105247375A (en) * 2013-06-13 2016-01-13 三菱电机株式会社 Power measurement device, determination method, and program

Also Published As

Publication number Publication date
TW201323885A (en) 2013-06-16
TWI458991B (en) 2014-11-01
CN103748475A (en) 2014-04-23
WO2013030655A4 (en) 2013-05-02
JP2013050385A (en) 2013-03-14

Similar Documents

Publication Publication Date Title
WO2013030655A1 (en) Electricity meter
US20190324064A1 (en) Reduced cost ratio metric measurement technique for tariff metering and electrical branch circuit protection
US11215650B2 (en) Phase aligned branch energy meter
US9146264B2 (en) Current meter with on board memory
US8570715B2 (en) Load center with branch-level current sensors integrated into power buses on a unit with on-board circuit breaker mounts
US9804211B2 (en) Indicators for a power meter
US10006948B2 (en) Current meter with voltage awareness
JP5939304B2 (en) Distribution board, power consumption management system, and manufacturing method thereof
JP5258815B2 (en) Power measurement system
JPWO2012133756A1 (en) Power consumption management system
US11137421B1 (en) Non-contact voltage sensing system
JP2003222645A (en) Multicircuit power measuring device
US7928722B2 (en) Apparatus and method for voltage sensing in electrical metering systems
JP6548105B2 (en) Power measurement apparatus and power measurement system using the same
WO2013121507A1 (en) Current detector
JP2001208778A (en) Detected current combining apparatus and distribution board
JP6471990B2 (en) Conductive bar, distribution board cabinet and distribution board
CA2808735A1 (en) Load center with branch-level current sensors integrated into power buses on a unit with on-board circuit breaker mounts
US20190187191A1 (en) Energy metering for a building
JP6528322B2 (en) Measurement system, distribution board, and construction method of measurement system
JP6968629B2 (en) Distribution board
JP6260822B2 (en) Distribution board cabinet and distribution board
JP6876959B2 (en) Circuit judgment system, circuit judgment method, and program
JP6447910B2 (en) Setting device, distribution board, and measurement system
JP2019068668A (en) Distributing board

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 12828513

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 12828513

Country of ref document: EP

Kind code of ref document: A1