JP2009105483A - Pseudo communication network for power line communication - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pseudo communication network for power line communication for accurately measuring a disturbance wave generated on a power line. <P>SOLUTION: In the pseudo communication network for power line communication, a power terminal 110 for measurement is connected to a power line communication device 50. An impedance stabilizing circuit 120 holds a predetermined degree of balancing and impedance. A power line 130 for measurement connect the power terminal 110 for measurement to the impedance stabilizing circuit 120. A current probe 140 measures a current flowing through the power line 130 for measurement. A current measurement terminal 150 is for observing the current measured by the current probe 140. Here, the power terminal 110 for measurement, impedance stabilizing circuit 120, power line 130 for measurement, and current probe 140 are stored in a single metal housing. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power line communication pseudo communication circuit network for measuring an interference wave generated on a power line, and more particularly to a power line communication pseudo communication circuit network for accurately measuring an interference wave generated on a power line.

  In power line communications (PLC), a power line laid in a house is used as a communication transmission path to perform data communication. In a power line communication device that uses such a power line or a dedicated communication line as a communication transmission path, there is a possibility that a conducted interference wave leaks from the transmission path to the outside via the ground plane (ground return path). If this conducted disturbance becomes large, it may adversely affect the equipment installed in the vicinity, so it is generally regulated by laws and standards, and the conducted interference must be measured correctly. . A method for measuring a conducted interference wave in these power line communication devices is described in Non-Patent Document 1, for example.

In power line communication using a power line, there is a possibility that a conducted disturbance wave becomes large due to the influence of an unbalanced element caused by the power line, a home appliance connected to the power line, a switch, grounding, or the like. The main factor is that a high-frequency signal in balanced mode output on the power line as a signal for power line communication is converted into a high-frequency signal in unbalanced mode (that is, a conducted interference wave) due to the influence of the unbalanced element. is there. Therefore, in order to correctly measure the conducted interference wave, a pseudo communication network for power line communication in consideration of unbalance specific to the power line is required.
Notification of Ministry of Internal Affairs and Communications No. 520 (Provision of measurement method for current and voltage of conducted disturbances and electric field strength of radiated disturbances)

  However, the conventional pseudo communication network for power line communication generally uses an impedance stabilization circuit that defines power line balance and common mode impedance at a power supply terminal for measurement. FIG. 6 is a diagram illustrating an example of a method of measuring a conducted disturbance current in a conventional power line communication device. In the measurement method using the impedance stabilization circuit 620 shown in FIG. 6, the balance and the common mode impedance are ensured only at the measurement power terminal 610 to which the power plug of the power line communication device 50 as the device under test is connected. Met.

  Therefore, when actually measuring the conducted interference wave, a large measurement error may occur due to a slight difference in the arrangement of the measurement system, and the result is often different depending on the measurer. Further, the current probe 640 arranged 10 cm away from the power line terminal only measures the conducted interference wave of the power line that is a part of the power line communication device 50, and the conducted interference wave is originally increased. The value due to a potential power line unbalance factor could not be measured.

  In addition, in the conventional pseudo-communication network for power line communication, there is an impedance difference between each lead of the power line for measurement and the metal housing in order to reproduce the unbalance specific to the power line. The measurement result may differ depending on the insertion direction of the power plug of the power line communication device 50.

  Therefore, the object of the present invention is to provide a configuration that correctly reflects the unbalance of the power line transmission line and the common mode impedance in the measurement value, and regardless of the arrangement of the measurement system or the difference in the insertion direction of the power plug. An object is to provide a pseudo communication network for power line communication capable of highly reproducible measurement even when a measurer performs measurement.

  The present invention is directed to a power line communication device pseudo communication network for measuring an interference wave current of a power line communication device that performs communication via a power line. In order to achieve the above object, the power line communication pseudo-communication network of the present invention includes a power supply terminal for measurement connected to the power line communication device, an impedance stabilization circuit that holds a predetermined balance and impedance, and measurement. A measurement power supply line connecting the power supply terminal for measurement and the impedance stabilization circuit, a current probe for measuring a current flowing through the measurement power supply line, and a current measurement terminal for observing a current measured by the current probe. However, the measurement power supply terminal, the impedance stabilization circuit, the measurement power supply line, and the current probe are configured to be housed in a single metal casing.

  As a result, in the pseudo communication network for power line communication of the present invention, the measurement power supply terminal, the impedance stabilization circuit, the measurement power supply line, and the current probe are arranged in the same metal casing. Therefore, it is possible to perform conducted interference wave measurement with high reproducibility compared to conducted interference wave measurement on the power source line of the device under measurement whose measurement results depend on the discretion of the measurer and the conditions of the device under measurement.

  The measurement power line is a power line that is standardized so that the common mode impedance is smaller than a predetermined value and the degree of balance is larger than a predetermined value in all frequency bands used for power line communication. It is characterized by being.

  As a result, the pseudo communication network for power line communication of the present invention has the same value for the common mode impedance and balance as the impedance stabilization circuit even in the measurement power supply terminal connected to the impedance stabilization circuit via the measurement power supply line. Can be kept.

  Further, the current probe and the measurement power supply line are respectively fixed at predetermined positions in the metal casing, and the relative positions of the current probe, the measurement power supply line, and the metal casing are unchanged.

  Thereby, the pseudo communication network for power line communication according to the present invention does not cause a measurement error due to a difference in measurement position of the measurement power supply line penetrating the current probe. In addition, since errors due to electromagnetic coupling and induction occurring between the current probe, the measurement power supply line, and the metal casing do not occur, the reproducibility of measurement can be further improved.

  Further, the measurement power supply line has two conductors, and the power line communication pseudo-communication network further includes a phase switching circuit that switches between the two conductors of the measurement power supply line. Features.

  As a result, the pseudo communication network for power line communication according to the present invention eliminates a measurement error due to the difference in the insertion direction of the power plug caused by the unbalance specific to the power line, and enables more accurate measurement of conducted interference.

  The pseudo communication network for power line communication further includes a voltage measurement terminal to which the voltage measurement device is connected, and a voltage measurement transformer connected to the measurement power supply line and the voltage measurement terminal. The primary impedance on the measurement power line side is higher than the impedance on the measurement power line, and the secondary impedance on the voltage measurement terminal side is equal to the impedance of the voltage measurement device, and the voltage measurement terminal is connected to the voltage measurement transformer. It is connected to the secondary side.

  Accordingly, the pseudo communication network for power line communication according to the present invention can measure the conducted disturbance wave current and also measure the signal voltage injected into the power line.

  According to the present invention, conducted disturbances caused by power line transmission line imbalance and common mode impedance are correctly measured, and any measurer can measure regardless of the arrangement of the measurement system or the difference in the insertion direction of the power plug. Even with this, measurement with high reproducibility becomes possible.

  Hereinafter, a pseudo communication network for power line communication according to each embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1A is a block diagram illustrating an example of a configuration of a pseudo communication circuit network for power line communication 100 according to the first embodiment of the present invention. 1A, the power line communication pseudo communication network 100 includes a measurement power supply terminal 110, an impedance stabilization circuit 120, a measurement power supply line 130, a current probe 140, and a current measurement terminal 150.

  The power line communication pseudo communication network 100 is installed on a metal plate, and connects a power line communication device 50, which is a device under measurement, installed on an insulating table and a power line communication device 51, which is an auxiliary communication device. The power line communication pseudo-communication network 100 is a device for measuring a conducted disturbance wave current generated during communication from the power line communication device 50 to the power line communication device 51.

  The measurement power supply terminal 110 is connected to the power line communication device 50. The power supply terminal for measurement 110 is a power supply terminal to the power line communication device 50 and at the same time is a communication terminal for power line communication. The measurement power supply terminal 110 is connected to the impedance stabilization circuit 120 via the measurement power supply line 130.

  The impedance stabilization circuit 120 presupposes an unbalanced element in the indoor power line system in the house, and defines the balance, the impedance in the common mode, and the differential mode. The impedance stabilization circuit 120 can be configured as shown in FIG. 1B, for example. FIG. 1B shows an example of the configuration of the impedance stabilization circuit 120. In the example shown in FIG. 1B, the impedance stabilization circuit 120 shows a case where the input impedance is 100Ω, the common-mode impedance between the input and GND is 25Ω, and the balance with respect to the input GND is 16 dB. The value is only an example.

  The measurement power line 130 simulates an indoor power line. With this configuration, the power line communication signal injected from the power line communication device 50 is converted into a conducted disturbance wave due to the unbalance of the impedance stabilization circuit 120, and the conducted disturbance wave flows to the measurement power supply line 130. Since the conduction interference wave generated in the measurement power supply line 130 is detected by the current probe 140, it can be observed from the current measurement terminal 150 connected to the current probe 140.

  As described above, according to the pseudo communication network for power line communication 100 according to the first embodiment of the present invention, the conduction disturbance generated by the mode conversion due to the unbalanced element peculiar to the power line is converted into the main body of the power line communication device 50. It is possible to easily measure without being affected by unbalanced elements and changes in common mode impedance caused by the installation status of the power supply and the handling of the power line.

  Further, as shown in FIG. 2, the power line communication pseudo-communication network 100 arranges the measurement power supply line 130 at the center of the current probe 140 so that an electromagnetic wave between the metal housing and the measurement power supply line 130 is obtained. It is possible to reduce measurement errors due to dynamic coupling or induction. Furthermore, even if the position of the current probe 140 in the metal casing is equidistant from all surfaces, the electromagnetic influence between the metal casing and the measurement power supply line 130 can be reduced, and the measurement error can be reduced. It becomes possible. In the above description, the distance between the impedance stabilization circuit 120 and the current probe 140 is not particularly defined. However, the measurement accuracy can be further improved by shortening the distance.

(Second Embodiment)
FIG. 3 is a block diagram showing an example of the configuration of a pseudo communication circuit network for power line communication 200 according to the second embodiment of the present invention. In FIG. 3, the power line communication pseudo communication network 200 includes a measurement power supply terminal 110, an impedance stabilization circuit 120, a measurement power supply line 230, a current probe 140, and a current measurement terminal 150. In the power line communication pseudo-communication network 200, components having the same functions as those of the power line communication pseudo-communication network 100 according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified. .

  In the power line communication pseudo-communication network 200, instead of the measurement power supply line 130 used in the first embodiment, the measurement power supply line 230 is standardized so that the common mode impedance is small and the balance is large. Is used. Examples of the measurement power supply line 230 include a twisted pair cable in which two wires are stranded. The method of measuring the conducted disturbance current in the power line communication pseudo communication network 200 is the same as that of the first embodiment.

  In other words, the power line communication pseudo-communication network 200 uses a twisted pair cable having a small common mode impedance and a high degree of balance as the measurement power supply line 230. Therefore, even in the measurement power supply terminal 110, the common mode impedance and The balance can maintain the same value as that of the impedance stabilization circuit 120. As a result, the effect of facilitating calibration while satisfying the standard as the pseudo communication network 200 for power line communication can be obtained.

  Furthermore, the conduction disturbance wave current generated by the mode conversion by the impedance stabilization circuit 120 may cause a slight error due to electromagnetic coupling or induction between the measurement power supply line 230 and the metal housing. In the measurement power supply line 230 having a small common mode impedance, these electromagnetic influences can be reduced, and the measurement accuracy can be further improved.

(Third embodiment)
FIG. 4A is a block diagram illustrating an example of a configuration of a pseudo communication circuit network for power line communication 300 according to the third embodiment of the present invention. 4A, the power line communication pseudo communication network 300 includes a measurement power supply terminal 110, an impedance stabilization circuit 120, a measurement power supply line 130, a current probe 140, a current measurement terminal 150, and a phase switching circuit 360. Is done. In the power line communication pseudo communication network 300, components having the same functions as those of the power line communication pseudo communication network 100 according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified. .

  In addition to the configuration of the power line communication pseudo communication network 100 according to the first embodiment, the power line communication pseudo communication network 300 further includes a phase switching circuit 360. Examples of the phase switching circuit 360 include a configuration as shown in FIG. 4B. In the conducted interference wave current measurement in the power line communication pseudo communication network 300, the power line communication signal of the power line communication device 50 is transmitted to the impedance stabilization circuit 120 via the phase switching circuit 360.

Here, the conduction disturbance current generated by the impedance stabilization circuit 120 will be described with reference to FIG. 4C. In FIG. 4C, when a differential input (V _{PLC in the} figure) is injected into the unbalanced circuit, mode conversion is performed by the unbalanced circuit, and a common mode current IC is generated. Here, the common mode current IC is added to the differential currents I ₁ and I ₂ by the original differential input V _PLC as IC ₁ and IC ₂ , respectively. IC ₁ and IC ₂ are not necessarily equal because the circuit is unbalanced (ie, IC ₁ = IC ₂ is not true). The conduction disturbance current IC ′ observed by the current probe 140 is expressed as IC ′ = (I ₁ + IC ₁ ) − (I ₂ −IC ₂ ). At this time, if the power line communication device 50 is perfectly balanced, the power line communication signal V _PLC is a differential signal, so I ₁ = I ₂ , and the observed conducted disturbance current IC ′ is IC '= IC ₁ + IC ₂ = IC.

However, in general, it is difficult for the power line communication device 50 to maintain perfect balance, and I ₁ −I ₂ = I _PLC is generated as a common mode current due to an unbalanced component of the power line communication device 50. . In this case, the observed conducted disturbance current IC ′ is IC ′ = IC + I _PLC . When such an unbalanced current due to the power line communication device 50 is observed, assuming that the power plug of the power line communication device 50 is inserted in the opposite direction, the unbalanced phase is reversed, and thus the power line communication device 50 is unbalanced. The common mode current I _PLC resulting from the equilibrium is I _PLC = I ₂ −I ₁ . Therefore, the observed conducted interference wave current IC ′ is IC ′ = IC−I _PLC , and a different value is detected depending on the insertion direction of the power plug.

  In order not to cause a measurement error due to such a measurement method, it is necessary to perform measurement while fixing the insertion direction of the power plug. However, depending on the measurer, there is a high possibility that the insertion direction of the power plug is different. Therefore, in the present embodiment, the phase switching circuit 360 switches the phase of the power line communication signal within the power line communication pseudo communication network 300. As a result, it is possible to measure two conducted interference wave currents IC ′ generated by changing the insertion direction of the power plug without changing the insertion direction of the power plug, and accurately measure the conducted interference wave current. Can do.

  Note that the phase switching circuit 360 is not only capable of performing manual switching and performing two measurements, but can also perform automatic switching and measure only the larger conducted interference wave current.

(Fourth embodiment)
FIG. 5A is a block diagram showing an example of the configuration of a pseudo communication network 400 for power line communication according to the fourth embodiment of the present invention. 5A, the power line communication pseudo communication network 400 includes a measurement power supply terminal 110, an impedance stabilization circuit 420, a measurement power supply line 130, a current probe 140, a current measurement terminal 150, a voltage measurement terminal 470, and a voltage measurement transformer. 480. In the power line communication pseudo communication network 400, components having the same functions as those of the power line communication pseudo communication network 100 according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified. .

  In the power line communication pseudo-communication network 400, in addition to the function of measuring the conducted disturbance wave current, the voltage measurement transformer 480 is further provided to enable voltage measurement. In the voltage measurement transformer 480, the impedance on the primary side (power supply line side used for communication in this embodiment) is sufficiently higher than the impedance of the power supply line, and the impedance on the secondary side (voltage measurement terminal side) Uses a transformer having the same impedance as the voltage measuring machine connected to the voltage measuring terminal 470. For example, FIG. 5B is an example. FIG. 5B shows a configuration in which the voltage measurement transformer 480 is arranged inside the impedance stabilization circuit 420, but the voltage measurement transformer 480 is arranged anywhere as long as it is connected to the measurement power supply line 130. May be.

  According to this configuration, the primary impedance of the voltage measurement transformer 480 is sufficiently higher than the impedance of the measurement power supply line 130, and therefore affects the conducted disturbance current flowing in the measurement power supply line 130 and the power line communication signal. It is possible to measure the power line communication signal voltage between two lines of the measurement power line 130 without any problem.

  As a result, not only the measurement person's discretion, but also measurement of the conducted disturbance current of the power line communication device with high reproducibility is possible, and in addition, the power line communication signal voltage can be measured. It can be easily applied to the inspection when manufacturing the power line communication device without depending on the measurement according to the above.

  INDUSTRIAL APPLICABILITY The present invention is useful as a pseudo communication network or the like that can measure the conducted disturbance current of a power line communication device with high reproducibility.

The block diagram which shows an example of a structure of the pseudo | simulation communication network 100 for power line communications in the 1st Embodiment of this invention. The figure which shows an example of a structure of the impedance stabilization circuit 120 which concerns on the 1st Embodiment of this invention. The figure which shows the cross section of the pseudo | simulation communication network 100 for power line communications which concerns on the 1st Embodiment of this invention. The block diagram which shows an example of a structure of the pseudo | simulation communication network 200 for power line communications which concerns on the 2nd Embodiment of this invention. The block diagram which shows the structure of the pseudo | simulation communication network 300 for power line communications which concerns on the 3rd Embodiment of this invention. The figure which shows an example of a structure of the phase switching circuit 360 which concerns on the 3rd Embodiment of this invention. The figure explaining the conduction jamming current generated by the impedance stabilization circuit 120 concerning the 3rd Embodiment of this invention The block diagram which shows an example of a structure of the pseudo | simulation communication network 400 for power line communications which concerns on the 4th Embodiment of this invention. The figure which shows an example of a structure of the transformer for voltage measurement 480 which concerns on the 4th Embodiment of this invention. The figure which shows an example of the measuring method of the conduction disturbance wave current in the conventional power line communication apparatus

Explanation of symbols

100, 200, 300, 400 Pseudo communication network for power line communication 50, 51 Power line communication device 110, 610 Power supply terminal for measurement 120, 420, 620 Impedance stabilization circuit 130, 230 Power supply line for measurement 140, 640 Current probe 150 Current measurement Terminal 360 Phase switching circuit 470 Voltage measuring terminal 480 Voltage measuring transformer

Claims (5)

A pseudo-communication network for a power line communication device that measures a disturbance current of a power line communication device that performs communication via a power line,
A power supply terminal for measurement connected to the power line communication device;
An impedance stabilization circuit that maintains a predetermined balance and impedance;
A power line for measurement connecting the power terminal for measurement and the impedance stabilization circuit;
A current probe for measuring the current flowing in the measurement power line;
A current measuring terminal for observing a current measured by the current probe;
The pseudo power communication network for power line communication, wherein the power supply terminal for measurement, the impedance stabilization circuit, the power supply line for measurement, and the current probe are housed in a single metal casing.   The power supply line for measurement is a power supply line that is standardized so that the common mode impedance is smaller than a predetermined value and the degree of balance is larger than a predetermined value in all frequency bands used for power line communication. The pseudo-communication network for power line communication according to claim 1, wherein:   The current probe and the measurement power supply line are respectively fixed at predetermined positions in the metal casing, and the relative positions of the current probe, the measurement power supply line, and the metal casing are unchanged. The pseudo communication network for power line communication according to claim 1 or 2. The measurement power line has two conductors,
The pseudo-communication network for power line communication according to any one of claims 1 to 3, further comprising a phase switching circuit that switches between two conducting wires of the power supply line for measurement. A voltage measuring terminal to which a voltage measuring device is connected;
A voltage measurement transformer connected to the measurement power line and the voltage measurement terminal;
In the voltage measuring transformer, the primary impedance on the measurement power supply line side is higher than the impedance of the measurement power supply line, and the secondary impedance on the voltage measurement terminal side is equal to the impedance of the voltage measurement device. ,
5. The pseudo communication network for power line communication according to claim 1, wherein the voltage measurement terminal is connected to a secondary side of the voltage measurement transformer.

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