JP6375846B2 - Power measuring device, and method for determining connection state between AC circuit and power measuring device - Google Patents

Description

  The present invention measures the voltage and current of a three-wire AC circuit and measures and displays voltage, current, power, reactive power, power factor, frequency, energy, etc. This is related to the discrimination.

  In order to correctly calculate the measured value / measured value in an AC circuit, in general, input from a current transformer or transformer placed in the electric circuit is taken into the meter, but the connection is improper, so-called incorrect connection. If it is, proper display cannot be obtained.

  Therefore, the specific wiring status for the current transformer of the instrument (reverse connection or incorrect connection between R phase and S phase) is automatically determined from the phase angle between the current phases and the phase angle between the voltage and current. A three-phase, three-wire type power / watt-hour meter is proposed (for example, see Patent Document 1). At that time, a method of inputting a power factor condition to detect an erroneous connection even when the power factor is poor and automatically correcting the erroneous connection state is disclosed.

JP 2011-21986 (paragraphs 0018 to 0029, FIGS. 1 and 8 to 13)

  However, the above power / watt-hour meter can discriminate if there is a misconnection in the current transformer circuit.For example, even if the transformer is miswired, the current transformer is misidentified as having a misconnection. As a result, it was impossible to reliably determine misconnections. In other words, the method disclosed in Patent Document 1 cannot substantially accurately determine the erroneous connection, and cannot correct the error when there is an erroneous connection.

  The present invention has been made in order to solve the above-described problems. The power measuring device, the AC circuit, and the power measuring device capable of quickly determining the connection state and quickly correcting even if there is an erroneous connection. The purpose of this method is to obtain a connection state discrimination method.

  The power measurement device of the present invention is a power measurement device that is connected to a three-wire AC circuit and measures the power of the AC circuit, the voltage detection unit detecting a voltage signal of the AC circuit, and the AC circuit A current detection unit that detects a current signal of the current, and a measurement value calculation unit that calculates a measurement value of the power from the voltage signal detected by the voltage detection unit and the current signal detected by the current detection unit, For the phase equation, the combination of the input power factor condition and the voltage phase angle calculated using the detected voltage signal and current signal, the current phase angle, and the power phase angle is a single phase. For the equation, depending on whether the phase angle between the voltage and current calculated using the detected voltage signal and current signal, and the combination of the voltage values meet the respective criteria, the AC circuit Connection between the voltage detection unit and the current detection unit A connection state judgment unit for judging the state, and further comprising a.

  In the method for determining the connection state between the AC circuit and the power measuring device according to the present invention, when the AC circuit is a three-phase three-wire system, the power factor condition, the voltage phase angle, the current phase angle, and the power phase angle are used. If the combination is a single-phase three-wire system, the voltage detector and the current for the AC circuit depend on whether the phase angle between the voltage and the current and the combination of the voltage values meet the respective standards. It is characterized in that a connection state with a detection unit is determined.

  According to the method for determining the connection state between the power measuring device or the AC circuit and the power measuring device of the present invention, the connection state is determined based on whether or not the combination of data set in accordance with the phase wire system meets the standard. Therefore, it is possible to quickly determine the connection state and quickly correct even if there is an incorrect connection.

It is a block diagram for demonstrating the structure of the electric power measurement apparatus concerning Embodiment 1 of this invention. In the electric power measurement apparatus concerning Embodiment 1 of this invention, it is a figure which shows the screen display showing a misconnection. It is a figure which shows the state which connected the terminal of the electric power measurement apparatus concerning Embodiment 1 of this invention correctly to the transformer and the current transformer. It is a figure which shows a part of example of the connection pattern assumed in the electric power measurement apparatus concerning Embodiment 1 of this invention or the connection state determination method of an electric power measurement apparatus. It is a figure which shows a part of example of the connection pattern assumed in the electric power measurement apparatus concerning Embodiment 1 of this invention or the connection state determination method of an electric power measurement apparatus. It is a flowchart which shows the connection state discrimination | determination method of the electric power measurement apparatus concerning Embodiment 1 of this invention. It is a figure which shows the vector of a voltage and an electric current at the time of connecting the terminal of a transformer in a certain pattern with the terminal of electric power measurement apparatus. It is a figure which shows the vector of the electric power on a complex plane at the time of misconnecting the terminal of a transformer with a certain pattern to the terminal of electric power measurement apparatus. It is a block diagram for demonstrating the structure of the electric power measurement apparatus concerning Embodiment 2 of this invention. It is a figure which shows the example of the connection pattern assumed in the electric power measurement apparatus concerning Embodiment 3 of this invention or the connection state discrimination | determination method of an electric power measurement apparatus. It is a flowchart which shows the connection state discrimination | determination method of the electric power measurement apparatus concerning Embodiment 3 of this invention. It is a figure which shows the magnitude | size of a voltage and the vector of a voltage and an electric current at the time of connecting an electric circuit circuit incorrectly to the terminal of the electric power measurement apparatus concerning Embodiment 3 of this invention.

Embodiment 1 FIG.
FIGS. 1-8 is for demonstrating the structure of the electric power measurement apparatus concerning the Embodiment 1 of this invention or the connection state discrimination | determination method of an electric power measurement apparatus, and FIG. 1 is for demonstrating the structure of an electric power measurement apparatus. Fig. 2 is a diagram showing a screen display when the power measurement device detects a misconnection and switches from the measurement display to the misconnection display, and Fig. 3 shows the terminals of the power measurement device and the transformer to which the connection is made. FIG. 4 and FIG. 5 are diagrams showing examples of connection patterns assumed to be likely to occur in the connection work in the power measurement device or the connection state determination method of the power measurement device. FIG. 6 is a flowchart showing a method for determining the connection state of the power measuring device. 7 is a diagram showing voltage and current vectors when the terminals of the transformer are misconnected in the order of P2, P3, and P1 with respect to the P1, P2, and P3 terminals of the power measuring device, and FIG. These are the figures which show the vector of the electric power on a complex plane at the time of connecting the terminal of a transformer to the terminal of electric power measurement apparatus by the pattern mentioned above.

  As shown in FIG. 1, the power measuring apparatus 100 according to the first embodiment of the present invention detects the transformer output X200 and the current transformer output X300, generates (calculates) necessary data, and processes the data. Unit 1 and a display unit 2 for displaying the data processing result of the data processing unit 1. As will be described in detail later, the data processing unit 1 shown in FIG. 1 is necessary in the third to fifth embodiments in addition to the configuration (function) necessary for the power measuring device 100 according to the first embodiment. The structure which becomes is described.

  The data processing unit 1 detects a transformer output X200 and outputs a voltage signal Sv, a current detection unit 12 that detects a current transformer output X300 and outputs a current signal Si, and various measurement values A measurement value that includes a calculation unit 131 and a power / reactive power calculation unit 132, and calculates measurement values such as voltage, current, power, reactive power, power factor, frequency, and energy from the voltage signal Sv and the current signal Si. Based on the determination unit 13, the determination data generation unit 14 that generates (calculates) determination data for determining the connection pattern from the voltage signal Sv and the current signal Si, and the determination data generated by the determination data generation unit 14. And a connection state determination unit 15 for determining the presence and type of the connection. Note that the phase wire type discriminating unit 17 that discriminates whether the connected power is three-phase or single-phase based on the phase angle of the voltage is necessary in the fifth embodiment to be described later. You may prepare in the form 1.

  The discrimination data generation unit 14 includes a voltage phase angle calculation unit 141 that calculates a voltage phase angle φV, a current phase angle calculation unit 142 that calculates a current phase angle φI, and a power phase angle φP on a complex plane. A power phase angle calculation unit 143 to calculate and a power factor condition input unit 144 to obtain a power factor condition by manual input or the like are provided. The voltage-current phase angle calculation unit 145 that calculates the phase angle between current and voltage is necessary in the third to fifth embodiments to be described later, but may be provided in the first embodiment. Good.

  The connection state determination unit 15 includes a connection pattern determination reference storage unit 152 that stores an assumed connection pattern determination reference (a combination of φV, φI, φP, and power factor), and determination data generated by the determination data generation unit 14. Based on the discrimination criteria stored in the connection pattern discrimination criteria storage unit 152, a connection pattern discrimination unit 151 that discriminates the presence / absence of an incorrect connection and the type (connection pattern) of the incorrect connection pattern is provided.

  The display unit 2 displays measurement values such as voltage, current, power, reactive power, power factor, frequency, and electric energy based on the output from the measurement value calculation unit 13 (generates data for use). Based on the output from the unit 22, the connection state determination unit 15, the erroneous connection determination display unit 23 that displays the state of the connection pattern (generates data for use), and the display screen 2 d (FIG. 2) displays “measurement value”. And a display mode switching unit 21 for switching to either “display mode: display data from the measurement value display unit 22” or “incorrect connection display mode: display data from the erroneous connection determination display unit 23”. For example, the display mode switching unit 21 is provided with an input button or the like (not shown). By operating the input button, the display screen 2d displays “measurement value display mode” or “incorrect connection display mode”. The measured value and the connection state are displayed in either of the above. Needless to say, the display mode switching unit 21 may be switched to a mode in which nothing is displayed.

Next, the operation will be described.
First, “measurement value display mode”, that is, an operation when measuring a normal power value will be described. For example, if the power measurement device 100 is set to be in the “measurement value display mode” as a default, the display unit 2 basically has the voltage, current, power, and power calculated by the measurement value calculation unit 13. Measurement values such as reactive power, power factor, frequency, and energy are displayed. Or you may make it display only when the input button of the display mode switching part 21 is pushed and it switches to "measurement value display mode". Since such an operation is the same as that of a conventional power measuring device, the details are omitted, and the “misconnection display mode” that is the feature of the first embodiment, that is, the connection pattern in the three-phase three-wire system is used. The operation at the time of determination will be described in detail.

In the “incorrect connection display mode”, the presence / absence of an incorrect connection and the connection pattern are determined, and the determination result is displayed. In this case, the voltage phase angle calculator 141 and the current phase angle calculator 142 receive the voltage signal Sv and the current signal Si from the voltage detector 11 and the current detector 12, respectively, and the power phase angle calculator 143 A power signal Sp is output from the power / reactive power calculation unit 132. Here, when V _ij is defined as a voltage between the i-side terminal and the j-side terminal, the voltage phase angle calculation unit 141 calculates, for example, a phase angle between V ₁₂ and V ₃₂ (simply expressed as φV). The calculation result φV is output to the connection pattern discriminating unit 151. Further, if I _i is defined as a current flowing through the i-side terminal, the current phase angle calculation unit 142 calculates a phase angle between I ₁ and I ₃ (simply expressed as φI), and connects φI as a calculation result. The data is output to the pattern determination unit 151. Further, the power phase angle calculation unit 143 calculates the phase angle φP of the power vector on the complex plane, and outputs φP as the calculation result to the connection pattern determination unit 151.

  The power factor condition input unit 144 also includes data for selecting whether the power factor condition of the measurement circuit is “delayed”, “high power factor”, or “advance”. The selected data is output to the connection pattern discrimination unit 151.

  The connection pattern discriminating unit 151 discriminates the presence / absence of an erroneous connection and the type of the connection pattern by comparing the φV, φI, φP, and power factor conditions with the connection pattern discrimination criteria. Then, the determination result is output to the erroneous connection determination display unit 23. The misconnection determination display unit 23 displays a misconnection pattern, for example, as shown in FIG. 2 based on the determination result. FIG. 2 is a display example when the “measurement value display mode” and the “incorrect connection display mode” are switched and displayed on one screen 2d, and the region Dm indicates the “incorrect connection display mode”. A connection pattern is shown in Ds. For example, the physical terminal types (P1, P2, P3) of the power measuring device 100 are shown on the left side of the area Ds in FIG. 2, and the terminals actually connected are shown on the right side. As a result, it can be seen that the terminals of the transformer are connected to “P1, P2, P3 terminals” in the order of “P2, P3, P1”.

Next, the details of the connection pattern discrimination as described above will be described.
The power measuring device 100 and the AC circuit are connected (connected) by four signal lines for detecting the current of the AC circuit and three signal lines for detecting the voltage. In the first embodiment, as shown in FIG. 3, in a three-phase three-wire arrangement, for example, four current transformers 300a and 300b (collectively current transformers 300) that convert current signals are used. Three signal lines from two transformers 200a and 200b (collectively transformer 200) for converting signal lines and voltage signals are connected to the seven terminals 1S, 1L, 3S, 3L, P1, P2, and P3 of the power measuring device 100. When connecting, we extracted patterns that were considered necessary for practical use from possible connection patterns.

  Specifically, 1 pattern of normal connection, 1 pattern of reverse phase order in which 1 and 3 of the electric circuit are switched, 2 patterns of 3 connections that are wrong on the secondary side of the transformer 200, and 3 voltage terminals are mistaken An example of selecting (extracting) 5 patterns and 14 patterns shown in FIGS. 4 and 5 as discrimination targets in 4 patterns in which the connections on the secondary side of the two current transformers 300 are mistaken is shown. Expressed in another way, from the possible connection patterns, the above-mentioned error connection overlap (multiple errors), voltage application to the current circuit, current application to the voltage circuit, etc. Excludes extreme cases where burning and destruction occur. Although it is possible to discriminate other than the extracted pattern, the extracted pattern is a pattern that is likely to occur even in a qualified person such as an electrician, for example (generally likely to occur in the market). Therefore, by this extraction, the presence / absence of erroneous connection and the type of erroneous connection can be reliably determined by the combination of the aforementioned φI, φV, φP, and power factor. Furthermore, it is possible to compensate for erroneous connection by changing the wiring route described in the second embodiment.

  A more specific processing procedure of the connection pattern determination performed by the connection pattern determination unit 151 will be described with reference to the flowchart of FIG. As shown in Table 1, the connection pattern discrimination reference storage unit 152 stores combinations of information (discrimination data) necessary for pattern discrimination with respect to combinations of the voltage phase angle φV and the current phase angle φI. Further, as shown in Tables 2 to 4, the connection pattern discrimination reference storage unit 152 stores reference values (alternative or range) of patterns that can be discriminated for each combination of discrimination data necessary for pattern discrimination. Has been.

  Thus, in steps S110 to S130, it is determined which combination of discrimination data is necessary (whether or not discrimination data is increased). First, it is determined whether it can be determined only by the combination of the voltage phase angle φV and the current phase angle φI (step S110). If the determination is possible (Yes), the combination of φV and φI is based on the reference values shown in Table 2. It is determined whether the pattern is 5 or 14 (step S210).

  If it cannot be discriminated (No), it is judged whether it can be discriminated by the combination of φV, φI and φP plus the power phase angle φP (step S120). If it can be discriminated (Yes), based on the reference values shown in Table 3 , ΦV, φI, and φP are determined as any one of patterns 2, 3, 11, and 12 (step S220).

If it cannot be discriminated (No), it is judged whether it can be discriminated by a combination of φV, φI, φP and power factor conditions to which a power factor condition is further added (step S130). Based on the reference value, it is determined as one of patterns 1 and 6 to 10 by a combination of φV, φI, φP, and power factor conditions (step S230). Here, when it cannot be determined (No), based on the reference values shown in Table 4, it can be narrowed down to any one of patterns 4 and 13 by a combination of φV, φI, φP, and a power factor condition (step S240). ). In Table 4, the angle is described with the delay direction as the positive direction.

  Then, the discrimination results from steps S210 to 230 or the narrowing-down result in step S240 are output from the connection pattern discrimination unit 151 to the erroneous connection discrimination display unit 23 and displayed on the screen as shown in FIG. 2 (step S310).

As a specific example of the pattern determination, a description will be given of a connection state determination procedure in a case where the pattern number 9 “P1, P2, P3 terminals is connected to the terminals of the transformer 200 in the order of P2P3P1” shown in the lowermost part of FIG. To do. It is assumed that the voltage / current is in a high power factor state, the vectors of voltage (V ₁₂ and V ₃₂ ) and the vectors of current (I ₁ and I ₃ ) are the states shown in FIG. 7, and the power vector on the complex plane is Assume that the state shown in FIG. In FIG. 8, the positive rotation shows a delay.

  First, as shown in FIG. 7, since the voltage phase angle φV is 300 ° and the current phase angle φI is 240 °, the process proceeds to steps S110, S120, and S130 in sequence, and a combination of φV, φI, φP, and power factor conditions is used. It is determined that it can be determined. As shown in FIG. 8, φP is 240 ° and the input power factor condition is a high power factor. No. 9 connection pattern (step S230) can be determined. 9 connection patterns are displayed (step S310).

  In the first embodiment, by using φI, φV, φP and the power factor condition as discrimination data, an example of detecting a connection pattern in which any of transformer 200, current transformer 300, or voltage terminal is misconnected is detected. showed that. According to the above, it is possible to automatically discriminate 14 erroneous connection patterns that are likely to occur in the market, and it is possible to simplify the work for the user to investigate the connection pattern when an erroneous connection is made. On the other hand, by using the φI, φV, φP and power factor conditions as discrimination data, it is also possible to detect a connection pattern in which the transformer 200, the current transformer 300, and the voltage terminal are connected in error. It is also possible to provide a range for the determination criteria of φV and φI. And the change of the range of the determination angle by the change of power factor conditions can be changed similarly.

  In addition, the “incorrect connection display mode” may be switched by, for example, the display mode switching unit 21 as described above, but is automatically switched when connection work is performed or when power is newly turned on. It may be. Alternatively, regardless of the mode, the above-described determination (data processing) may be performed and automatically displayed when an erroneous connection is detected.

  As described above, according to the power measuring device 100 according to the first embodiment of the present invention, the power measuring device 100 is connected to a three-phase three-wire AC circuit and measures the power of the AC circuit. A voltage detector 11 for detecting a voltage signal of the circuit (transformer output X200), a current detector 12 for detecting a current signal of the AC circuit (current transformer output X300), and a voltage signal detected by the voltage detector 11 From the current signal detected by the current detector 12, a measured value calculator 13 for calculating a measured value of power, the input power factor condition, and the phase angle φV of the voltage calculated using the detected voltage signal and current signal Depending on whether or not the combination of the current phase angle φI and the power phase angle φP matches the standard (stored in the connection pattern discrimination reference storage unit 152), the voltage detector 11 and the current for the AC circuit With detection unit 12 Since the connection state determination unit 15 for determining the connection state is provided, it is possible to quickly determine the connection state (presence / absence of erroneous connection and type of erroneous connection), and quickly correct even if there is an erroneous connection. Can do.

  As described above, according to the connection state determination method between the AC circuit and the power measurement device according to the first exemplary embodiment of the present invention, the three-phase three-wire AC circuit and the power measurement device that measures the power of the AC circuit 100 is a method for determining a connection state with 100, using a step of inputting a power factor condition, a voltage signal detected by the voltage detector 11 and a current signal detected by the current detector 12, and a voltage phase angle φV and The combination of the step of calculating the current phase angle φI and the power phase angle φP, the power factor condition, the voltage phase angle φV, the current phase angle φI, and the power phase angle φP is (connection A connection state determination step of determining a connection state between the voltage detection unit 11 and the current detection unit 12 with respect to the AC circuit depending on whether or not the reference (stored in the pattern determination reference storage unit 152) is met. Since it is configured, a three-phase three-wire AC circuit and power Measured quickly determine the connection state (erroneous presence and erroneous type of connection of the connection) with the device 100, even if there is improper wiring can be corrected quickly.

  In particular, as a three-phase three-wire system, one pattern of reverse phase order in which 1 and 3 of the electric circuit are switched, two patterns that mistakenly connect the secondary side of the two transformers 200, and five patterns that mistakenly insert three voltage terminals Since a total of 14 patterns of 4 patterns and normal patterns that are mistaken in the connection on the secondary side of the two current transformers 300 are selected as discrimination targets, it is possible to reliably discriminate misconnections that are generally likely to occur in the market. .

Embodiment 2. FIG.
The power measuring device according to the second embodiment of the present invention is a device in which a function for correcting (automatically wiring) according to the determined misconnection pattern is added to the power measuring device according to the first embodiment. is there. Since other configurations and operations are the same as those in the first embodiment, description thereof is omitted. FIG. 9 is a block diagram for explaining the configuration of the power measurement device according to the second embodiment.

  As shown in FIG. 9, the power measuring device 100 according to the second embodiment of the present invention automatically causes erroneous connection to the data processing unit 1 described in FIG. 1 according to the first embodiment according to the connection pattern. A connection correction unit 16 to be corrected is additionally installed. More specifically, with respect to the data processing unit in the first embodiment, a part for detecting the transformer output X200 and the current transformer output X300 (voltage detection unit 11, current detection unit 12) and a part for performing arithmetic processing ( A connection correction unit 16 is provided (on the circuit) between the measurement value calculation unit 13 and the discrimination data generation unit 14). Further, the connection correction unit 16 receives the determination result from the connection state determination unit 15 so that the voltage and current can be corrected based on the connection pattern determined by the connection state determination unit 15 according to the correction method described later. It is connected to the.

  In addition to the configuration (function) required for the power measurement device 100 according to the second embodiment, the data processing unit 1 shown in FIG. The structure which becomes is described.

  The connection correction unit 16 includes the correction method selection unit 162 that selects a set correction method based on the determination result of the connection state determination unit 15 and the selection method selected by the correction method selection unit 162 as described above. A connection changing unit 161 that switches a wiring route (connection) between a part to be detected and a part to perform arithmetic processing is provided.

  The connection changing unit 161 is configured by a member that switches a wiring route such as a relay or a switch, and the correction method selecting unit 162 is a storage unit (not shown) that stores a pattern, or an input unit (not shown) that allows a user to input whether or not correction is possible. Etc. are constituted. In addition, although the example which switched the wiring path | route physically was shown in the figure, the change of a connection does not necessarily need to be the switching of a physical wiring path | route. For example, data may be switched or converted on software.

Table 5 is a correspondence table of correction (change) methods corresponding to the 14 connection patterns extracted for the three-phase three-wire system described in the first embodiment.

The connection pattern described in the first embodiment is No. An example in which it is determined that the terminal of the transformer is erroneously connected to P1, P2, and P3 terminals in the order of P2P3P1 will be described. When the connection state determination unit 15 determines that the connection pattern 9 is present, the information is output from the connection pattern determination unit 151 to the correction method selection unit 162. Then, the correction method selection unit 162, as a correction method corresponding to the connection pattern 9 in Table 5, V _3o (after correcting the incorrect connection) so that V _1o (V ₁₂ after correcting the incorrect connection) becomes V _3i −V _1i. The V ₃₂ ) is set to −V _1i so that the connection changing unit 161 is instructed. V _1i and V _3i respectively indicate V ₁₂ and V ₃₂ (in an erroneous connection state) input to the connection correction unit 16.

By changing the wiring path so that the connection changer 161 is in accordance with the instruction, the erroneous connection V ₃₂ and V ₁₂ input to the connection correction unit 16 are V _3o and V ₁₂ that are the original V ₃₂ and V _{12. 1o} is output to at least the measurement value calculation unit 13. Thereby, the measured value calculation part 13 can calculate a voltage, an electric current, electric power, reactive power, a power factor, a frequency, and electric energy similarly to having been normally connected.

  As described in the first embodiment, among the extracted 14 patterns, No. 4 and no. For 13, it is not possible to determine which pattern. However, in these patterns, the polarity of the voltage or the polarity of the current is reversed, and neither of them affects the calculation of the voltage value, the current value, and the frequency. Although it affects the calculation of power, reactive power, power factor, and energy, these can be calculated if the phase of the current with respect to the voltage is correct, so the method of reversing the polarity of the current or the method of reversing the polarity of the voltage But these measured and measured values can be calculated correctly. For this reason, the method is seemingly different as far as it is seen in the table. However, any method can be used to correct misconnections, so the correction method may be unified to either one. Or you may make it make a user select.

  In other words, it is possible to correct all the patterns for the extracted 14 patterns. As a result, the incorrect connection of the three-phase three-wire can be corrected automatically or with a simple operation that allows the user to select whether or not execution is possible. The work of reworking can be omitted.

  In the above description, an example in which correction is automatically performed when an erroneous connection can be determined has been described, but the present invention is not limited to this. For example, even when an erroneous connection is determined, correction may be performed after receiving permission (input) from the user. Further, when the data is corrected, it may be displayed that the data is correction data (physically there is an erroneous connection).

  The power measuring device 100 according to the second embodiment is connected between the voltage detection unit 11 and the measurement value calculation unit 13 and between the current detection unit 12 and the measurement value calculation unit 13 and is in a determined connection state. Accordingly, a connection correction unit 16 that corrects a wiring path between the voltage detection unit 11 and the measurement value calculation unit 13 or between the current detection unit 12 and the measurement value calculation unit 13 is provided. Even when an incorrect connection is made with a phase three-wire AC circuit, the power can be accurately measured without causing a power failure in the electric circuit and reconnection.

  In particular, as a three-phase three-wire system, one pattern of reverse phase order in which 1 and 3 of the electric circuit are switched, two patterns that mistakenly connect the secondary side of the two transformers 200, and five patterns that mistakenly insert three voltage terminals Since a total of 14 patterns of 4 patterns and normal patterns that are mistaken in the connection on the secondary side of the two current transformers 300 are selected as discrimination targets, the discriminated erroneous connection can be reliably corrected.

Embodiment 3 FIG.
The power measurement device and the connection state determination method of the power measurement device according to the first embodiment correspond to the three-phase three-wire system, but the power measurement device and the power measurement device according to the third embodiment of the present invention. This connection state discrimination method corresponds to the single-phase three-wire system. 10 to 12 are diagrams for explaining the configuration of the power measuring device or the connection state determining method of the power measuring device according to the third embodiment of the present invention. FIG. 10 shows the power measuring device in the single-phase three-wire system. Or the figure which shows the example of the connection pattern assumed that it is easy to occur by the wiring operation | work in the connection state determination method of an electric power measurement apparatus, FIG. 11 is a flowchart which shows the connection state determination method of an electric power measurement apparatus, FIG. FIG. 6 is a diagram showing a voltage and current vector (left side) and a voltage magnitude (right side) when an electric circuit is misconnected in a certain pattern. In the third embodiment, FIGS. 1 to 3 used in the description of the first embodiment are also used.

In the power measuring apparatus 100 according to the third embodiment of the present invention, at least the voltage-current phase angle calculation unit (indicated as φVI calculation unit in the figure) 145 is provided in the discrimination data generation unit 14 shown in FIG. . In addition to the voltage / current phase angle (referred to as φVI) from the voltage / current phase angle calculation unit 145, the connection pattern determination unit 151 includes voltage data (V ₁₂ , V ₃₂ ) from various measurement value calculation units 131. ) Is also entered. The connection pattern discrimination reference storage unit 152 stores a reference value necessary for discrimination of the connection pattern extracted according to the single-phase three-wire system. That is, the connection pattern discriminating unit 151 discriminates the presence / absence of an erroneous connection and the type of the connection pattern by comparing the phase angle between voltage and current and the voltage level with the reference for determining the connection pattern. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

In the voltage-current between the phase angle calculating section _145, the phase angle between _{V 12} and _{I 1} and (designated .phi.V ₁ I _1.), The phase angle between _{V 12} and _{I 3} (designated φV ₁ I _3.) And the calculated φVI is output to the connection state determination unit 15. The connection state determination unit 15 also outputs the voltage levels of V ₁₂ and V ₃₂ (hereinafter abbreviated as V) calculated by various measurement value calculation units 131.

Next, the details of the connection pattern discrimination according to the single-phase three-wire system will be described.
Also in the third embodiment, in the single-phase three-wire arrangement, as shown in FIG. 3 which uses the read-out phase names, one pattern of normal connection, five patterns in which three voltage terminals are mistakenly inserted, and An example in which a total of 10 patterns shown in FIG. 10 are selected (extracted) as discrimination targets in 4 patterns in which the secondary side connection of the two current transformers 300 is wrong is shown. Expressed in another way, only one of “connection to current transformer” and “connection to voltage terminal of meter” is misconnected, that is, a general misconnection pattern (9) that does not consider multiple errors. Ten patterns combined with the normal connection pattern (1) were detected.

  Although it is possible to discriminate other than the extracted pattern, the extracted pattern is likely to occur even for a person who is qualified to execute a connection such as an electrician (generally likely to occur in the market). ) Pattern. Therefore, by this extraction, the presence / absence of erroneous connection and the type of erroneous connection can be reliably determined by the combination of φVI and V described above. Furthermore, it is possible to compensate for erroneous connection by exchanging data, which will be described later in the fourth embodiment.

A more specific processing procedure of the connection pattern determination performed by the connection pattern determination unit 151 will be described with reference to the flowchart of FIG. In the connection pattern discrimination reference storage unit 152, as shown in Table 6, a combination of information (discrimination data) necessary for pattern discrimination with respect to a combination of two voltage-current phase angles φV ₁ I ₁ and φV ₁ I ₃ is stored. It is remembered. Further, as shown in Tables 7 and 8, the connection pattern discrimination reference storage unit 152 stores reference values (alternative or range) of patterns that can be discriminated for each combination of discrimination data necessary for pattern discrimination. Has been. In the table, the angle is described with the delay direction as the positive direction.

  Therefore, as shown in Tables 6 to 8, the connection pattern discrimination reference storage unit 152 stores reference values of patterns that can be discriminated for each combination of discrimination data necessary for discrimination of 10 patterns.

Thus, in steps S410 to S420, it is determined which combination of discrimination data is necessary (whether the discrimination data should be increased). First, it is determined whether or not discrimination is possible only by a combination of φV ₁ I ₁ and φV ₁ I ₃ (step S410). If discrimination is possible (Yes), φV ₁ I ₁ and φV ₁ I ₁ are determined based on the reference values shown in Table 7. It is determined whether the pattern is 2 or 3 depending on the combination of φV ₁ I ₃ (step S510).

If it cannot be determined (No), it is determined whether it can be determined by a combination of φVI and V to which voltage data (V ₁₂ , V ₃₂ ) is added (step S420). If it can be determined (Yes), the criteria shown in Table 8 are used. Based on the value, it is determined as any one of patterns 1, 6, 7, 9, and 10 by a combination of φVI and V (step S520).

  Here, if it cannot be determined (No), based on the reference values shown in Table 8, the combination of φVI and V can be narrowed down to either pattern 4 or 5 or 8 (step S530).

  Then, the discrimination results from step S510 to 520 or the narrowing-down result by step S530 are output from the connection pattern discrimination unit 151 to the erroneous connection discrimination display unit 23 and displayed on the screen as shown in FIG. 2 for assistance (step S610). .

As a specific example of the pattern determination, a connection state determination procedure in the case of incorrect connection in the pattern number 9 “P1, P2, P3 terminals in order of P2P3P1” shown in the lowermost part of FIG. 10 and the lower part of Table 9 will be described. It is assumed that the voltage is 110 V AC between 1 phase and 2 phases, and 3 phases and 2 phases, and the voltage between 1 phase and 3 phases is AC220V. The vectors of currents (I ₁ and I ₃ ) and voltages (V ₁₂ and V ₃₂ ) are in the state shown in FIG. In FIG. 12, the positive rotation shows a delay.

First, as shown in FIG. 12 (left side), since V ₁ I ₁ is 0 ° and V ₁ I ₃ is 180 °, the process proceeds from step S410 to step S420, and it can be determined by the combination of φVI and V. To be judged. Then, _{V 12} as shown in FIG. 12 (right side) is _110V, since _{V 32} is a 220V, No. Table 8 9 can be determined (step S520), and the determination result No. 9 is obtained. 9 connection patterns are displayed (step S610).

  In the third embodiment, an example in which a connection pattern in which either the current transformer 300 or the voltage terminal is erroneously connected is detected by using the voltage-current phase angle φVI and the voltage V as discrimination data has been described. As described above, it is possible to automatically discriminate 10 erroneous connection patterns that are likely to occur in the market, and it is possible to simplify the work for the user to investigate the connection pattern when an erroneous connection is made. On the other hand, by using the voltage-current phase angle φVI and the voltage V as discrimination data, it is also possible to detect a connection pattern in which the transformer 200, the current transformer 300, and the voltage terminal are connected in error. It is also possible to provide a range for the criterion for determining the voltage-current phase angle φVI and the voltage V. In the third embodiment, the reference voltage V is AC 110V. However, the reference voltage V can be changed in accordance with the target electric circuit.

  As described above, according to the power measuring device 100 according to the third embodiment of the present invention, the power measuring device 100 is connected to a single-phase three-wire AC circuit and measures the power of the AC circuit. A voltage detector 11 for detecting a voltage signal of the circuit (transformer output X200), a current detector 12 for detecting a current signal of the AC circuit (current transformer output X300), and a voltage signal detected by the voltage detector 11 A measured value calculation unit 13 for calculating a measured value of power from the current signal detected by the current detection unit 12, and a phase angle between the voltage and the current calculated using the detected voltage signal and the current signal (phase angle between voltage and current) φIV) and the voltage value V are connected with the voltage detection unit 11 and the current detection unit 12 for the AC circuit depending on whether or not the combination (stored in the connection pattern discrimination reference storage unit 152) matches the reference. Determine the state A line state judgment unit 15, since it is configured to include, to determine the connection state (erroneous existence of connection and erroneous type of connection) quickly, even with improper wiring can be corrected quickly.

  As described above, according to the connection state determination method for the power measurement device according to the third embodiment of the present invention, the connection between the single-phase three-wire AC circuit and the power measurement device 100 that measures the power of the AC circuit. A method for determining a state, a step of calculating a phase angle φVI between a voltage and a current and a voltage value V using the voltage signal detected by the voltage detector 11 and the current signal detected by the current detector 12; Depending on whether or not the combination of the phase angle φVI between the voltage and the current and the voltage value V matches the reference (stored in the connection pattern discrimination reference storage unit 152), the voltage detector 11 and the current for the AC circuit And a connection state determination step for determining a connection state with the detection unit 12. Therefore, the connection state between the single-phase three-wire AC circuit and the power measuring device 100 (presence / absence of incorrect connection and incorrect connection) Type) quickly, incorrect connection Even if there is, it can be corrected quickly.

  In particular, for the single-phase, three-wire system, 5 patterns in which three voltage terminals are mistakenly inserted, and four patterns in which the connections on the secondary side of the two current transformers 300 are mistaken and normal patterns are selected as a discrimination target. Therefore, it is possible to reliably determine misconnections that are likely to occur in the market.

Embodiment 4 FIG.
As in the second embodiment, the power measuring device according to the fourth embodiment of the present invention is different from the power measuring device according to the third embodiment in accordance with the determined misconnection pattern (wiring is automatically performed). A function to be corrected is added. That is, an erroneous connection is determined corresponding to the single-phase three-wire system, and the wiring route is changed according to the determined connection pattern. Since other configurations and operations are the same as those in the third embodiment, the description thereof is omitted. And in this Embodiment 4, FIG. 9 and FIG. 10 which were used in Embodiment 2 are used.

  Also in the fourth embodiment, the connection correction unit 16 selects the correction method selection unit 162 that selects the set correction method and the correction method selection unit 162 based on the determination result of the connection state determination unit 15. In accordance with the selection method, there is provided a connection changing unit 161 that switches a wiring path (connection) between the portion to be detected and the portion that performs arithmetic processing. Based on the connection pattern determined by the connection state determination unit 15, the connection correction unit 16 receives the determination result from the connection state determination unit 15 so that the voltage and current can be corrected according to the correction method according to the single-phase three-wire system. Connected to input.

  Table 9 is a correspondence table of correction (change) methods according to ten connection patterns extracted for the single-phase three-wire system described in the third embodiment.

The connection pattern described in the third embodiment is No. An example when it is determined that the electric circuit voltage is 9 (in order of P2P3P1 to the P1P2P3 terminal) will be described. When the connection state determination unit 15 determines that the connection pattern 9 is present, the information is output from the connection pattern determination unit 151 to the correction method selection unit 162. Then, the correction method selection unit 162, as a correction method corresponding to the connection pattern 9 in Table 9, V ₃₂ after correcting the erroneous connection so that V _1o, which is V ₁₂ after correcting the erroneous connection, becomes V _3i −V _1i. An instruction is given to the connection changing unit 161 so that V _3o becomes −V _1i .

By changing the wiring path so that the connection changer 161 is in accordance with the instruction, the erroneous connection V ₃₂ and V ₁₂ input to the connection correction unit 16 are V _3o and V ₁₂ that are the original V ₃₂ and V _{12. 1o} is output to at least the measurement value calculation unit 13. Thereby, the measured value calculation part 13 can calculate voltage, electric current, electric power, frequency, and electric energy similarly to having been normally connected.

  As described in the third embodiment, among the extracted 10 patterns, No. 4 and no. 5 and no. For 8, it is not possible to determine which pattern. Of these, No. 5 and no. As for 8, the calculation of the voltage value, current value, and frequency is not affected by using any pattern as in 4 and 13 in the second embodiment. Although it affects the calculation of electric power and electric energy, these can be calculated if the phase of the current with respect to the voltage is correct, so these measured values can be obtained either by reversing the polarity of the current or by reversing the polarity of the voltage. The measured value can be calculated correctly.

  On the other hand, no. No. 4 pattern is No. 5 or No. Unlike the correction method of 8, it is necessary to select another correction method. However, whether the pattern is one of the three narrowed-down patterns can be distinguished by simply observing the connection state without checking data or the like. Therefore, no. Whether or not it is 4 is determined by the user, and a correction method is selected (input). In addition, No. 5 and no. The correction method for any one of 8 may be unified to either one, but the user may be allowed to select.

  That is, among the extracted 10 patterns, at least 7 patterns can be automatically determined, and the patterns can be automatically corrected. In addition, the three patterns that have been narrowed down can be easily distinguished from each other without the need to power out the electric circuit. As a result, the erroneous connection of the single-phase three-wire can be corrected automatically or with a simple operation that allows the user to select whether to execute or not. Therefore, when an incorrect connection is made, it is possible to omit the work of the user powering down the electric circuit and reconnecting.

  In the fourth embodiment, an example in which correction is automatically performed when an erroneous connection can be determined has been described. However, the present invention is not limited to this. For example, even when an erroneous connection is determined, correction may be performed after receiving permission (input) from the user. Further, when the data is corrected, it may be displayed that the data is correction data (physically there is an erroneous connection). In the fourth embodiment, as in the second embodiment, the correction of the wiring path is not limited to a physical change and can be performed on software.

  As described above, according to the power measuring apparatus 100 according to the fourth embodiment, the connection is made between the voltage detection unit 11 and the measurement value calculation unit 13 and between the current detection unit 12 and the measurement value calculation unit 13. And a connection correction unit 16 that corrects a wiring path between the voltage detection unit 11 and the measurement value calculation unit 13 or between the current detection unit 12 and the measurement value calculation unit 13 according to the determined connection state. Since it is provided, even when an incorrect connection is made with a single-phase three-wire AC circuit, the electric power can be accurately measured without causing a power failure in the electric circuit and reconnection.

  In particular, for the single-phase, three-wire system, 5 patterns in which three voltage terminals are mistakenly inserted, and four patterns in which the connections on the secondary side of the two current transformers 300 are mistaken and normal patterns are selected as a discrimination target. Therefore, the determined erroneous connection can be reliably corrected.

Embodiment 5. FIG.
In the said Embodiment 1-4, the structure corresponding to the phase wire type of either one phase or three phases was demonstrated. In the power measuring device and the method for determining the connection state of the power measuring device according to the fifth embodiment, it is determined by automatically determining whether the electric circuit provided with the meter is a three-phase three-wire type or a single-phase three-wire type. The pattern is discriminated in accordance with the phase line type, and in some cases, further correction can be made. The configuration of the power measuring device according to the fifth embodiment will be described with reference to FIG. 1 or FIG. 9 used in the first or second embodiment.

  As shown in FIG. 1 or FIG. 9, the power measuring device 100 according to the fifth embodiment of the present invention adds a phase / line type determination unit 17 to the data processing unit 1 described in the first to fourth embodiments. It is a thing. More specifically, the phase and wire type discriminating unit 17 receives the output (φV) from the voltage phase angle calculating unit 141, discriminates the phase and wire type based on the inputted φV, and determines the discrimination result Ip. It arrange | positions so that it may output to the measured value calculating part 13 and the connection state discrimination | determination part 15. FIG.

  The measurement value calculation unit 13 is set to switch the calculation method according to the phase-wire type discrimination result Ip. In addition, the connection pattern discrimination reference storage unit 152 stores both the single-phase reference value and the three-phase reference value, and the connection pattern discrimination unit 151 stores the phase-line discrimination result Ip. Accordingly, the data used for discrimination and the discrimination method are switched. The discrimination data generation unit 14 includes the calculation units (141 to 145) described in FIGS. 1 and 9 and outputs necessary discrimination data in response to a request from the connection pattern discrimination unit 151.

  In the fifth embodiment as well, in FIG. 9 to be used, the correction method selection unit 162 stores the correction methods corresponding to both phase line types, and not only the determined pattern number but also the phase line. If the formula discrimination result Ip is also input, the erroneous connection can be corrected according to the discriminated phase line formula and pattern as described in the second or fourth embodiment.

  Next, processing of the phase wire type determination unit 17 will be described. When the single-phase three-wire system is normal, the phase angle between the two-side reference one-side voltage and the two-side reference three-side voltage is 180 °, so that φV is 0 ° or 180 °. In the three-phase three-wire system, the phase angle between the two-side reference one-side voltage and the two-side reference three-side voltage is 300 °, and φV can be 0 ° or 180 ° even if miswired Absent. Therefore, the phase wire type discriminating unit 17 discriminates a single phase three wire type if φV is 0 ° or 180 °, and a three phase three wire type otherwise.

  As described above, in either the three-phase three-wire type or single-phase three-wire type electric circuit, the phase wire type can be automatically discriminated by one power measuring device 100 without changing the meter, and the measurement / measurement is performed. Can be done.

  As described above, according to the power measuring device 100 according to the fifth embodiment, the power measuring device 100 is connected to the three-wire AC circuit and measures the power of the AC circuit, and the voltage signal of the AC circuit is measured. Based on the voltage detector 11 that detects (transformer output X200), the current detector 12 that detects the current signal (current transformer output X300) of the AC circuit, and the voltage signal detected by the voltage detector 11, the AC circuit A phase wire type discriminating unit 17 for discriminating the phase wire type, a voltage signal and the current signal detected by the current detecting unit 12, and a measured value calculating unit 13 for calculating a measured value of power from the discriminated phase wire type; If the determined phase wire type is a three-phase type, the input power factor condition, the voltage phase angle φV calculated using the detected voltage signal and current signal, the current phase angle φI, and the power phase angle The combination of φP meets the standard for three-phase type If the determined phase wire type is a single-phase type, the phase angle between the voltage and current calculated using the detected voltage signal and current signal (voltage-current phase angle φIV), and the voltage value V It is configured to include a connection state determination unit 15 that determines a connection state between the voltage detection unit 11 and the current detection unit 12 with respect to the AC circuit depending on whether or not the combination meets the single-phase standard. Therefore, it is possible to quickly determine the connection state regardless of which phase line type AC circuit is connected, and to quickly correct any erroneous connection.

  In particular, the voltage detection unit 11 and the measurement value calculation unit 13 are connected between the voltage detection unit 11 and the measurement value calculation unit 13 and between the current detection unit 12 and the measurement value calculation unit 13, and the voltage detection unit 11 and the measurement value calculation unit according to the determined connection state. 13, or a connection correction unit 16 that corrects a wiring path between the current detection unit 12 and the measurement value calculation unit 13. Even when an incorrect connection is made, it is possible to accurately measure the electric power without causing a power failure in the electric circuit and reconnection.

  Moreover, according to the connection state determination method between the AC circuit and the power measurement device according to the fifth exemplary embodiment of the present invention, the connection state between the 3-wire AC circuit and the power measurement device 100 that measures the power of the AC circuit. A phase line type determining step for determining the phase line type of the AC circuit based on the voltage signal detected by the voltage detection unit 11 of the power measuring device 100, and the determined phase line type is a three-phase type. In this case, the input power factor condition, the voltage phase angle φV calculated using the voltage signal detected by the voltage detection unit 11 and the current signal detected by the current detection unit 12, the phase angle φI of the current, the power If the determined phase wire type is a single phase type depending on whether or not the combination of the phase angles φP matches the standard for the three-phase type, the voltage and current calculated using the detected voltage signal and current signal Phase angle (phase angle between voltage and current φIV) and voltage value V A connection state determination step of determining a connection state between the voltage detection unit 11 and the current detection unit 12 with respect to the AC circuit depending on whether or not the combination meets a single-phase type standard. Therefore, it is possible to quickly determine the connection state regardless of which phase line type AC circuit is connected, and to quickly correct any erroneous connection.

  In each of the above-described embodiments, an example is shown in which discrimination data is determined based on specific phases or data between phases, but it goes without saying that the combination of phases may be changed as appropriate.

1: Data processing unit 2: Display unit 2d: Display screen 11: Voltage detection unit 12: Current detection unit 13: Measurement value calculation unit 14: Discrimination data generation unit 15: Connection state determination unit 16 : Connection correction unit, 17: phase wire type determination unit, 21: display mode switching unit, 22: measurement value display unit, 23: erroneous connection determination display unit, 100: power measuring device,
131: Various measurement value calculation units, 132: Power / reactive power calculation units,
141: voltage phase angle calculation unit, 142: current phase angle calculation unit, 143: power phase angle calculation unit, 144: power factor condition input unit, 145: voltage-current phase angle calculation unit,
151: Connection pattern determination unit, 152: Connection pattern determination reference storage unit,
161: Connection change unit 162: Correction method selection unit,
300: current transformer, 300a: I1 current transformer, 300b: I3 current transformer,
Dm: Mode display, Ds: Connection status display,
I _i : current of i phase, Ip: discrimination result of phase wire system, P _i : power of i phase, Si: current signal, Sp: power signal, Sv: voltage signal, V _ij : voltage between i phase and j phase , (The subscript i or j is one of 1, 2, 3), X200: transformer output, X300: current transformer output,
φI: (for example) current phase angle between 1 phase and 3 phase, φP: power phase angle between 1 phase and 3 phase (for example) on complex plane, φV: (for example) voltage between 1 phase and 2 phase and 3 phase Voltage phase angle between two phases, φV ₁ I ₁ : phase angle between V ₁₂ and I ₁ , φV ₁ I ₃ : phase angle between V ₁₂ and I ₃

Claims (7)

A power measuring device connected to a three-phase three-wire AC circuit and measuring the power of the AC circuit,
A voltage detector for detecting a voltage signal of the AC circuit;
A current detector for detecting a current signal of the AC circuit;
From the voltage signal detected by the voltage detection unit and the current signal detected by the current detection unit, a measurement value calculation unit that calculates the measurement value of the power,
Depending on the input power factor condition and whether the combination of the voltage phase angle calculated using the detected voltage signal and current signal, the current phase angle, and the power phase angle meets the criteria. A connection state determination unit for determining a connection state between the voltage detection unit and the current detection unit with respect to the AC circuit;
A power measuring device characterized by comprising: A power measuring device connected to a single-phase three-wire AC circuit and measuring the power of the AC circuit,
A voltage detector for detecting a voltage signal of the AC circuit;
A current detector for detecting a current signal of the AC circuit;
From the voltage signal detected by the voltage detection unit and the current signal detected by the current detection unit, a measurement value calculation unit that calculates the measurement value of the power,
The voltage detection unit for the AC circuit and the phase angle between two voltage currents calculated using the detected voltage signal and current signal, and whether a combination of two voltage values meets a reference or not. A connection state determination unit for determining a connection state with the current detection unit;
A power measuring device characterized by comprising: A power measuring device connected to a three-wire AC circuit and measuring the power of the AC circuit,
A voltage detector for detecting a voltage signal of the AC circuit;
A current detector for detecting a current signal of the AC circuit;
A phase wire type discriminating unit for discriminating a phase wire type of the AC circuit based on the voltage signal detected by the voltage detecting unit;
From the voltage signal detected by the voltage detection unit, the current signal detected by the current detection unit, and the determined phase wire type, a measurement value calculation unit that calculates the measurement value of the power,
When the determined phase wire type is a three-phase type, the input power factor condition, the voltage phase angle calculated using the detected voltage signal and current signal, the current phase angle, and the power phase angle Depending on whether or not the combination of these matches the standard for the three-phase system,
When the determined phase wire type is a single phase type, the phase angle between the voltage and current calculated using the detected voltage signal and current signal, and the combination of the voltage values match the standard for the single phase type. Depending on whether or not
A connection state determination unit for determining a connection state between the voltage detection unit and the current detection unit with respect to the AC circuit;
A power measuring device characterized by comprising: The voltage detection unit and the measurement value calculation unit are connected between the voltage detection unit and the measurement value calculation unit, and between the current detection unit and the measurement value calculation unit, and according to the determined connection state, the voltage detection unit and the measurement value calculation unit, Or a connection correction unit that corrects a wiring path between the current detection unit and the measurement value calculation unit,
The power measuring device according to any one of claims 1 to 3, further comprising: A method for determining a connection state between a three-phase three-wire AC circuit and a power measuring device for measuring the power of the AC circuit,
Entering a power factor condition;
Calculating a voltage phase angle, a current phase angle, and a power phase angle using the voltage signal detected by the voltage detection unit of the power measuring device and the current signal detected by the current detection unit;
Depending on whether a combination of the power factor condition, the phase angle of the voltage, the phase angle of the current, and the phase angle of the power meets a standard, the voltage detection unit and the current for the AC circuit A connection state determination step for determining a connection state with the detection unit;
A method for determining a connection state between an AC circuit and a power measuring device. A method for determining a connection state between a single-phase three-wire AC circuit and a power measuring device for measuring the power of the AC circuit,
Using the voltage signal detected by the voltage detection unit of the power measuring device and the current signal detected by the current detection unit to calculate two voltage-current phase angles and two voltage values;
Connection for determining a connection state between the voltage detection unit and the current detection unit with respect to the AC circuit depending on whether a combination of the phase angle between the two voltage currents and the two voltage values meets a reference A state determination step;
A method for determining a connection state between an AC circuit and a power measuring device. A method for determining a connection state between a three-wire AC circuit and a power measuring device for measuring the power of the AC circuit,
Based on the voltage signal detected by the voltage detector of the power measuring device, a phase wire type determination step of determining the phase wire type of the AC circuit;
When the determined phase wire type is a three-phase type, the input power factor condition, the phase angle of the voltage calculated using the detected voltage signal and the current signal detected by the current detection unit, and the phase angle of the current And depending on whether the combination of phase angle of power meets the standard for three-phase type,
When the determined phase wire type is a single phase type, the phase angle between the voltage and current calculated using the detected voltage signal and current signal, and the combination of the voltage values match the standard for the single phase type. Depending on whether or not
A connection state determination step of determining a connection state between the voltage detection unit and the current detection unit with respect to the AC circuit;
A method for determining a connection state between an AC circuit and a power measuring device.

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