JP2008236700A - Method of investigating influence exerted upon power line communication by electric device, and noise measuring instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of easily and surely investigating the influence exerted upon power line communication by an electric device connected to a power line, and a noise measuring instrument therefor. <P>SOLUTION: A modulation signal generating section 4A generates a modulation signal under control of a control section 3, and a modulation signal transmitting section 4B transmits the modulation signal with predetermined output. A modulation signal receiving section 6B receives a power line communication signal superimposing a power line communication signal from the modulation signal transmitting section 4B and a signal (also including noise from power wiring connected to a power supply cable 1B and an outlet 2) passed through a coupling section 5. On the basis of an instruction of a personal computer 40, the control section 3 transmits a signal for measurement of predetermined output, acquires the status of a reception signal at that time from a modulation signal demodulating section 6A, and detects the status of noise passed through the coupling section 5. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for investigating the influence of electrical equipment connected to a power line on power line communication, and a noise measuring device for measuring the state of noise mixed in the power line performing power line communication.

  In power line communication, communication is performed using a power line for supplying commercial power as a transmission path. Since the power line used as the transmission line is for supplying power to other electric devices, the other electric devices are usually connected and in an operating state. Therefore, the influence by the electric equipment in operation (for example, the influence by the electromagnetic noise which an electric equipment emits) cannot be avoided. When the influence is great, it is necessary to take some measures such as stopping the use of the electrical equipment.

  Patent Documents 1 and 2 describe techniques for reducing the influence of electric equipment connected to indoor power wiring on power line communication. In the techniques described in these documents, a filter is inserted between the indoor wiring and the electric device to reduce electromagnetic noise entering and exiting from the electric device via the power line.

  In order to take these measures, it is necessary to identify an electrical device that has a great influence on power line communication, but a method for easily and accurately identifying it has not been proposed.

JP 2003-283390 A JP 2003-218754 A

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for easily and surely investigating the influence of electrical equipment connected to a power line on power line communication, and a noise measuring device therefor.

  The influence investigating method of the present invention is an influence investigating method for investigating the influence of electric equipment connected to a power line on power line communication, and the power in phase with the electric power supplied to the power wiring to which the electric equipment is connected. A transmission step of transmitting the power line communication signal by connecting the first power line communication device to the supplied power wiring, and reception of receiving the power line communication signal by the second power line communication device connected to the power wiring. And a noise information calculating step of calculating noise information in power line communication based on the power line communication signal received in the receiving step.

  ADVANTAGE OF THE INVENTION According to this invention, the influence which the electric equipment connected to the power line has on power line communication can be investigated easily and reliably. That is, the influence on the power line communication of the electrical equipment can be grasped from the noise information when the electrical equipment to be investigated is connected to the power wiring and operating.

  The influence investigation method of the present invention includes a method in which the first power line communication device is connected to a power wiring connected to the same circuit breaker as the power wiring to which the electric device is connected. ADVANTAGE OF THE INVENTION According to this invention, the influence which an electric equipment has on power line communication can be grasped | ascertained more accurately and easily. Here, the power wiring to which the first power line communication device is connected may be a power wiring branched from the power wiring connected to one circuit breaker.

  The influence investigation method of the present invention includes a method in which the first power line communication device and the second power line communication device are connected to the same outlet. According to the present invention, it is possible to grasp the influence of the electric appliance on the power line communication more reliably.

  The influence investigation method of the present invention further includes a noise information output step of outputting the noise information calculated in the noise information calculation step. According to the present invention, it is possible to quickly grasp the influence of electrical equipment on power line communication. When outputting the noise information, it is possible to display it later by simply taking a log at the time of investigation, or to display the noise level.

  In the influence investigating method of the present invention, the noise information calculating step calculates the noise information based on the power line communication signal in a predetermined period during which the electric device is operating, and the noise information output step includes the noise information Including output of time fluctuations. According to the present invention, it is possible to grasp the influence of the electric device based on fluctuations in noise information.

  The influence investigating method of the present invention includes a method in which the noise information calculating step calculates the noise information based on the power line communication signal when the electric device is operating and the power line communication signal when the electric device is not operating. According to the present invention, it is possible to estimate the amount of fluctuation of noise information during connection to, disconnection from, or operation and non-operation from the outlet as noise caused by the electric device, and more reliably investigate the influence of the electric device. be able to. In other words, since the influence of noise can be measured with high accuracy, it is possible to easily identify the noise source by determining the magnitude of the influence of the noise when the connection state of the electrical device that may be a noise source is changed. be able to.

  According to an influence investigation method of the present invention, the first power line communication device and the second power line communication device each include a transmission unit that transmits a power line communication signal and a reception unit that receives a power line communication signal. It is comprised by a communication apparatus, The said transmission part and the said receiving part include what can operate | move simultaneously.

  According to the influence investigation method of the present invention, the first power line communication device and the second power line communication device are connected to the same computer, and the first power line communication device is based on an instruction from the computer. A transmission step is executed, and the second power line communication device executes the reception step and the noise information calculation step based on an instruction from the computer.

  The influence investigation method of the present invention includes the method in which the noise information calculation step calculates a transmission rate of the power line communication signal or a ratio between the signal level of the power line communication signal and noise.

  The noise measurement device of the present invention is a noise measurement device that measures the state of noise mixed in a power line that performs power line communication, a signal generation unit that generates a first power line communication signal having a predetermined output, and the power line And a coupling unit that is connected to a line that can be connected to the signal line and that passes a signal in a frequency band that includes the frequency band of the first power line communication signal, and a signal that has passed through the coupling unit is superimposed on the first power line communication signal And a noise state detection unit for detecting a state of noise from the line based on the second power line communication signal.

  ADVANTAGE OF THE INVENTION According to this invention, the noise measuring device for investigating easily and reliably the influence which the electric equipment connected to the power line has on power line communication can be provided. By connecting this measuring device to a predetermined outlet and measuring the state of noise, turning on / off the electrical equipment connected to the same outlet, or connecting / disconnecting the electrical equipment from the outlet, the electrical equipment Whether or not it is a noise source can be determined. For example, if the state of noise hardly changes regardless of whether the operation of the electrical device is on or off, it can be determined that the electrical device is not a noise source. Further, when the noise greatly increases when the operation of the electric device is changed to ON, it can be determined that the electric device is a noise source.

  The noise measurement apparatus according to the present invention further includes an attenuation unit that attenuates a power line communication signal, and the attenuation unit includes one that is connected between the signal generation unit and the coupling unit. According to the present invention, the level of the transmitted power line communication signal is attenuated, so that it is easily affected by noise on the receiving side (noise detecting unit side), and therefore a small noise source can be specified.

  The noise measuring device of the present invention includes an apparatus in which the attenuation amount of the attenuation unit can be changed. According to the present invention, the influence of noise can be accurately detected by changing the level of the transmitted power line communication signal in accordance with the noise level to be detected. In other words, by adding a function for attenuating (variing), the signal level on the receiving side is small, so that even if the level of the noise source is small, it is easily affected. Therefore, even such a small noise source can be identified.

  The noise measuring device of the present invention further includes a noise measuring device that outputs a time variation of the noise state detected by the noise state detecting unit.

  In the noise measuring device of the present invention, the noise detecting unit calculates a transmission rate of the power line communication signal or a ratio between a signal level of the power line communication signal and noise.

  The noise measuring apparatus of the present invention is a noise measuring apparatus that measures the state of noise mixed in a power line that performs power line communication, and is connected to the power line and capable of transmitting at least a power line communication signal. Connected to the power line, the second power line communication apparatus capable of receiving at least a power line communication signal, connected to the first power line communication apparatus and the second power line communication apparatus, and mixed into the power line A control device that controls measurement of a noise state to be transmitted, wherein the control device instructs the first power line communication device to transmit a power line communication signal for measuring a noise state in power line communication. In addition, it instructs the second power line communication device to receive a power line communication signal and to calculate noise information in power line communication based on the received power line communication signal. Then, the first power line communication device generates and transmits a power line communication signal for measuring a noise state in the power line communication based on an instruction from the control device, and the second power line communication device Based on the instruction of the control device, the reception of the power line communication signal and the calculation of noise information in the power line communication based on the received power line communication signal are performed.

  ADVANTAGE OF THE INVENTION According to this invention, the noise measuring device for investigating easily and reliably the influence which the electric equipment connected to the power line has on power line communication can be provided. Moreover, since an existing apparatus is used as the power line communication apparatus constituting the measuring apparatus, it can be easily configured. By connecting this measuring device to a predetermined outlet and measuring the noise state, turning on / off the electrical equipment connected to the same outlet, or connecting / disconnecting the electrical equipment from the outlet, the electrical equipment Whether or not it is a noise source can be determined. For example, when the state of noise hardly changes regardless of whether the operation of the electric device is on or off, it can be determined that the electric device is not a noise source. Further, when the noise greatly increases when the operation of the electric device is changed to ON, it can be determined that the electric device is a noise source.

  The noise measuring device of the present invention includes a device in which the power cable of the first power line communication device and the power cable of the second power line communication device are connected to one power plug. According to the present invention, the structure becomes simple and the handling becomes easy.

  The noise measuring device of the present invention further includes an attenuator for attenuating a power line communication signal, and the attenuator includes one inserted in a power supply line of the first power line communication device. According to the present invention, the level of the transmitted power line communication signal is attenuated, so that it is easily affected by noise on the receiving side (noise detecting unit side), and therefore a small noise source can be specified.

  The noise measuring device of the present invention includes an apparatus in which the attenuation amount of the attenuation unit can be changed. According to the present invention, the influence of noise can be accurately detected by changing the level of the transmitted power line communication signal in accordance with the noise level to be detected. In other words, by adding a function for attenuating (variing), the signal level on the receiving side is small, so that even if the level of the noise source is small, it is easily affected. Therefore, even such a small noise source can be identified.

  The noise measurement device of the present invention further includes a device including a noise information output unit that outputs a temporal variation of the noise state detected by the second power line communication device.

  The noise measuring device of the present invention includes a device in which the second power line communication device calculates a transmission rate of the power line communication signal or a ratio between the signal level of the power line communication signal and noise.

  As is clear from the above description, according to the present invention, it is possible to provide a method for easily and surely investigating the influence of electrical equipment connected to a power line on power line communication, and a noise measuring device therefor.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of a wiring example for indoor power supply to which the influence investigation method of the present invention is applied. The influence investigating method of the present invention is to perform the influence of the electric equipment connected to the power wiring when performing power line communication via the power wiring as shown in FIG. 1 using a noise measuring device. . Although FIG. 1 shows a single-phase three-wire power supply, the power supply is not limited to a single-phase three-wire system. In the following explanation, as a general rule, the term “power line” refers to a general line that uses power transmission or supply, and “power wiring” is an individual that actually supplies power to electrical equipment or outlets in the home. Used to refer to the track.

  As shown in FIG. 1, the power supply to indoor rooms R1, R2, R3, R4, etc. is divided into a distribution board (breaker box) BB connected to a lead-in line (not shown), and power wiring L11, This is performed via L12, L13, L21, L22, and L23. In the distribution board BB, a main breaker (ampere breaker) AB, an earth leakage breaker ELCB, and a child breaker (wiring breaker, safety breaker) B11, B12, B13, B21, B22, B23 are provided. The lead-in wire (not shown) is connected to the main breaker AB, and then connected to the leakage breaker ELCB. The power wiring from the main breaker AB and the earth leakage breaker ELCB consists of the first voltage line L1, the second voltage line L2, and the neutral line N. The first power line L1 and the neutral line N are the child breakers B11, B12, and B13. The second power line L2 and the neutral line N are connected to the child breakers B21, B22, B23. Therefore, the power wirings L11, L12, and L13 connected to the child breakers B11, B12, and B13 and the power wirings L21, L22, and L23 connected to the child breakers B21, B22, and B23 supply power whose phases are reversed. It will be.

  The power wirings L11, L12, L13, L21, L22, and L23 are each connected to a specific room or an outlet for a specific device. In FIG. 1, the power wiring L11 is connected to the outlet C11 of the room R1, and the outlets C21 and C22 of the room R2, and the power wiring L21 is connected to the outlets C31 and C32 of the room R3 and the outlets C41 and C42 of the room R4. However, the other power wirings L12, L13, L22, and L23 are also connected to a specific outlet or the like (not shown).

  In FIG. 1, electric devices S1, S2, N1, N2, and N3 are connected to outlets C21, C31, C11, C32, and C41, respectively. Here, the electric devices S1 and S2 are electric devices that generate a relatively small amount of noise, and the electric devices N1, N2, and N3 are electric devices that generate a relatively large amount of noise. Also, PLC (Power Line Communication) modems PLCA and PLCB are connected to outlets C22 and C42, respectively, so that power line communication is possible. Therefore, data can be transmitted and received between the personal computer PCA connected to the PLC modem PLCA and the personal computer PCB connected to the PLC modem PLCB.

  When the electric devices S1, S2, N1, N2, and N3 are connected and operating, the power line communication between the modems PLCA and PLCB is affected in some way, and if the effect is large, measures must be taken. There is. As a method of investigating the influence of the electric devices S1, S2, N1, N2, and N3, data is transmitted from the personal computer PCA connected to the PLC modem PLCA in a plurality of states in which each device is operated or not operated. There is a method of measuring and displaying the data received by the personal computer PCB connected to the PLC modem PLCB, the level ratio between noise and signal, and the like. However, since the influence on the power line communication of the electronic device connected to the power wiring varies greatly depending on the connected wiring, it is difficult to specify an electronic device that is a noise source, in particular, an electronic device that is a plurality of noise sources. That is, the influence varies greatly depending on the phase difference of the power wiring, and also varies depending on the difference of the connected child breakers even if the power wiring has the same phase.

  As another method for investigating the influence of power line communication between the modems PLCA and PLCB from the electric devices S1, S2, N1, N2, and N3, the electric devices S1, S2, N1, N2, and N3, respectively. Is connected to or disconnected from the outlets C11, C21, C31 to C41, data is transmitted from the personal computer PCA connected to the PLC modem PLCA and received by the personal computer PCB connected to the PLC modem PLCB. It is conceivable to display the measured data and noise / signal level ratio.

  FIG. 2 shows an example of the connection state of the noise measuring apparatus when the influence investigation method of the present invention is implemented. The noise measuring device measures the state of noise mixed in a power line that performs power line communication, and includes a first PLC modem 51, a second PLC modem 52, and a personal computer 50. In FIG. Is for investigating the influence of the electrical equipment N2 connected to the outlet C41. The first PLC modem 51 functions as a first power line communication device for transmitting a power line communication signal to the power line L21, and the second PLC modem 52 is a second power line for receiving the power line communication signal. Functions as a power line communication device. The personal computer 50 calculates and outputs noise information in power line communication based on the power line communication signal received by the second PLC modem 52.

  When investigating the influence of the electric device N2, as will be described in detail later, noise information when the electric device N2 is connected and put into an operating state, and the electric device N2 in a non-operating state (the power switch of the electric device N2 is turned off) Or a state in which the power plug is removed from the outlet C41). For example, when the noise information largely fluctuates between the operating state and the non-operating state, it is determined that the influence on the power line communication of the electric device N2 is large.

  In this case, it is preferable to investigate the power wiring L21 without connecting other electrical devices (or with the power off), but this is not always necessary because there is attenuation due to the distance between the outlets. However, only the electric device (in this case, electric device N2) whose influence is to be investigated is connected to the outlet (in this case, outlet C41) to which the measuring device is connected. If the measuring device cannot be connected to the same outlet as the outlet to which the electrical device whose effect is to be investigated is connected, connect to the power wiring (in this case, the power wiring L21) connected to the same child breaker in the same phase. Connect the measuring device to an outlet as close as possible. Furthermore, when it cannot connect to the electric power wiring connected to the same child breaker, you may connect to a different child breaker with the same phase.

(First embodiment)
FIG. 3 shows a schematic functional block diagram of an example of a PLC modem that functions as the noise measurement apparatus according to the first embodiment of the present invention. The PLC modem is an example of a power line communication device, but a certain function is added to function as a noise measurement device.

  3 includes a control unit 3, a modulation signal generation unit 4A, a modulation signal transmission unit 4B, a coupling unit 5, a modulation signal reception unit 6B, a modulation signal demodulation unit 6A, and a display unit 7. The PLC modem 10 is connected to the outlet 2 (the outlet C41 to which the electric device N2 is connected in FIG. 2) via the power cable 1B and also connected to the personal computer 40.

  The modulation signal generation unit 4A generates a modulation signal modulated by data to be transmitted under the control of the control unit 3, and the modulation signal transmission unit 4B receives the modulation signal generated by the modulation signal generation unit 4A. It transmits with a predetermined output. The output of the transmission signal may be fixed or may be changed by an instruction from the control unit 3. Therefore, a power line communication signal having a predetermined output is generated by the modulation signal generation unit 4A and the modulation signal transmission unit 4B.

  The coupling unit 5 is connected to the modulation signal transmission unit 4B, the modulation signal reception unit 6B, and the power cable, and has a frequency band including the frequency band of the modulation signal (power line communication signal) transmitted from the modulation signal transmission unit 4B. The signal is passed. Therefore, the power line communication signal from the modulation signal transmission unit 4B is transmitted through the power wiring connected to the outlet 2 via the power cable 1B and is received by the modulation signal reception unit 6B.

  The modulation signal reception unit 6B receives at least a communication signal in the frequency band of the power line communication signal transmitted from the modulation signal transmission unit 4B. Therefore, the modulation signal receiving unit 6B receives the power line communication signal from the modulation signal transmission unit 4B and the signal that has passed through the coupling unit 5 (including noise from the power wiring connected to the power cable 1B and the outlet 2). The superimposed power line communication signal is received.

  The modulated signal demodulator 6A demodulates the power line communication signal from the modulated signal receiver 6B to obtain received data. The control unit 3 controls the overall operation of the PLC modem 10 and, when operating as a noise measuring device, causes a measurement signal having a predetermined output to be transmitted based on an instruction from the personal computer 40. Then, the state of the received signal at that time is acquired from the modulation signal demodulating unit 6A, and the state of the noise that has passed through the combining unit 5 is detected. The detection result may be displayed on the display unit 7 or may be sent to the personal computer 40 and output by the personal computer 40.

  The noise state is determined by calculating a signal level to noise ratio such as CINR (Carrier to Interferene and Noise Ratio), an error rate of transmission data, a transmission rate, and the like.

  Next, a specific configuration example of the PLC modem 10 shown in FIG. 3 is shown. 4A and 4B are views showing an overview of the PLC modem 10, in which FIG. 4A is an external perspective view showing the front, FIG. 4B is a front view, and FIG. 4C is a rear view. The PLC modem 10 shown in FIG. 4 has a housing 100. On the front surface of the housing 100, as shown in FIGS. 4 (a) and 4 (b), LEDs (Light Emitting Diodes) 23A, 23B, and 23C are provided. The display unit 23 is provided. Further, as shown in FIG. 4 (c), a power connector 21 and a modular jack 22 for LAN (Local Area Network) such as RJ45, and a changeover switch 101 for changing the operation mode are provided on the rear surface of the casing 100. Is provided. A power cable (not shown in FIG. 4) is connected to the power connector 21 and a LAN cable (not shown in FIG. 4) is connected to the modular jack 22. The PLC modem 10 may further be provided with a Dsub (D-subminiature) connector to connect a Dsub cable.

  FIG. 5 is a block diagram illustrating an example of hardware of the PLC modem 10. As shown in FIG. 5, the PLC modem 10 includes a circuit module 30 and a switching power supply 20. The switching power supply 20 supplies various (for example, + 1.2V, + 3.3V, + 12V) voltages to the circuit module 30, and includes, for example, a switching transformer and a DC-DC converter (none of which are shown). Consists of. Power is supplied to the switching power supply 20 from the power supply connector 21 via the impedance upper 27 and the AC / DC converter 24.

  The circuit module 30 includes a main IC (Integrated Circuit) 11, an AFE / IC (Analog Front END / Integrated Circuit) 12, a low-pass filter (LPF) 13, a driver IC 15, a coupler 16, a band-pass filter (BPF) 17, and a memory 18. And an Ethernet PHY IC (Physical Layer Integrated Circuit) 19 is provided. The coupler 16 is connected to the power connector 21 and further connected to the power line 1A via the power cable 1B, the power plug 25, and the outlet 2. The display unit 23 is connected to the main IC, and the modular jack 22 is connected to a LAN cable 26 for connecting to a device such as a personal computer. The main IC 11 functions as a control circuit when performing power line communication and when performing noise measurement.

  The main IC 11 is constituted by a CPU (Central Processing Unit) 11A, a PLC / MAC (Power Line Communication / Media Access Control Layer) block 11C1, 11C2, and a PLC / PHY (Power Line Communication / Physical 1) block 11B. Yes. The CPU 11A has a 32-bit RISC (Reduced Instruction Set Computer) processor. The PLC / MAC block 11C2 manages the MAC layer (Media Access Control layer) of the transmission signal, and the PLC / MAC block 11C1 manages the MAC layer of the reception signal. The PLC / PHY block 11B2 manages a PHY layer (Physical layer) of a transmission signal, and the PLC / PHY block 11B1 manages a PHY layer of a reception signal. The AFE / IC 12 includes a DA converter (DAC) 12A, an AD converter (ADC) 12D, and variable amplifiers (VGA) 12B and 12C. The coupler 16 includes a coil transformer 16A and coupling capacitors 16B and 16C. The CPU 11A uses the data stored in the memory 18 to control the operation of the PLC / MAC blocks 11C1 and 11C2 and the PLC / PHY blocks 11B1 and 11B2, and also controls the entire PLC modem 10.

  Each element in the PLC modem 10 shown in FIG. 3 roughly corresponds to the element shown in FIG. That is, the control unit 3 corresponds to the CPU 11 </ b> A, the coupling unit 5 corresponds to the coupler 16, and the display unit 7 corresponds to the display unit 23. The modulation signal generation unit 4A and the modulation signal transmission unit 4B correspond to the PLC / MAC block 11C2, the PLC / PHY block 11B2, the DAC 12A, the variable amplifier 12B, the low-pass filter 13, and the driver IC 15, and correspond to the modulation signal demodulation unit 6A. The signal receiving unit 4B corresponds to the PLC / MAC block 11C1, the PLC / PHY block 11B1, the ADC 12D, the variable amplifier 12C, and the band-pass filter 17.

  Communication by the PLC modem 10 is performed as follows. Data input from the modular jack 22 is sent to the main IC 11 via the Ethernet PHY IC 19, and a digital transmission signal is generated by performing digital signal processing. The generated digital transmission signal is converted into an analog signal by the DA converter (DAC) 12A of the AFE / IC 12, and the low-pass filter 13, the driver IC 15, the coupler 16, the power connector 21, the power cable 1B, the power plug 25, the outlet 2 Is output to the power line 1A.

  The signal received from the power line 1A is sent to the band pass filter 17 via the coupler 16, and after the gain is adjusted by the variable amplifier (VGA) 12C of the AFE / IC 12, it is digitalized by the AD converter (ADC) 12D. Converted to a signal. The converted digital signal is sent to the main IC 11 and converted into digital data by performing digital signal processing. The converted digital data is output from the modular jack 22 via the Ethernet PHY • IC 19.

  FIG. 6 shows a schematic operation flow when the state of noise mixed in the power line is measured using the PLC modem 10 described above. When measuring the state of noise mixed in the power line, the PLC modem 10 of FIG. 3 is connected to the outlet 2, and the noise measurement operation is started by the personal computer 40. Note that the function of the personal computer 40 can also be realized by the PLC modem 10.

  In step S101, a CE (Channel Estimation) command issuance period and an information reading period are set. This setting content is stored in a memory of a personal computer (not shown). In step S102, a CE command is issued to the PLC modem 10.

  The PLC modem 10 that has received the CE command performs transmission / reception of a power line communication signal for noise measurement, and calculation and storage of noise information under the control of the control device 3. Specifically, a power line communication signal with a predetermined output is transmitted from the modulation signal transmission unit 4B, and the modulation signal reception unit 6B is simultaneously operated to receive a power line communication signal on which noise is superimposed via the power cable 1B. . Then, the received signal is demodulated, carrier detection, synchronization detection, and error detection are performed, and noise information is calculated. The noise information is, for example, CINR. The calculated noise information is stored in the memory 18.

  The personal computer 40 reads the noise information stored in the memory 18 in step S103. In step S104, the received data is output or displayed. In step S105, it is determined whether or not the set period has elapsed. If it has elapsed, the process returns to step S102 and is repeated. If it has not elapsed, data is transmitted (step S106), and it is determined whether the end of measurement is instructed. If the end of measurement is instructed, the measurement is ended. If not instructed, the process returns to step S105. Note that step S106 may be omitted depending on the noise measurement method.

  In this flow, the personal computer reads out and uses the noise information calculated by the modulation signal demodulator 6A. However, the personal computer reads out the statistical information of the PLC / PHY block 11B1 constituting the modulation signal demodulator 6A, and the personal computer Information may be calculated.

  It is also possible to use an error amount for data received as noise information. When determining the noise mixed in the power line by the error amount, it is necessary to transmit a certain amount of data packets. Therefore, in step S101, it is also preferable to perform not only the CE command but also a command for continuously transmitting data. .

  Next, a schematic operation in the case of measuring the state of noise mixed in the power line performing power line communication using this PLC modem 10 and specifying an electric device that is a noise generation source will be described. FIG. 7 is a diagram showing a schematic procedure for investigating the influence of electrical equipment connected to power wiring on power line communication.

  In step S201, the PLC modem 10 is connected to the outlet 2 to which the electrical device to be measured is connected. Next, in step S202, an electrical device to be measured is connected to the outlet 2, and the power supply is turned on to enter an operating state (hereinafter simply referred to as “connection”). In this state, noise measurement is instructed from the computer 40 connected to the PLC modem 10, and noise measurement is started (step S203). The process of step S203 is performed in the procedure as shown in FIG. In step S204, the measurement result during operation of the electrical equipment connected to the outlet 2 is acquired from the PLC modem 10 and output.

  Next, the electrical device to be measured is disconnected from the outlet 2 (step S205). Note that this step may be a process of turning off the power of the electric device with the power plug connected (hereinafter simply referred to as “disconnection” or “non-operation”). Then, noise measurement is started in step S206, and a measurement result is acquired and output in step S207. Steps S206 and S207 are the same processing as steps S203 and S204.

  Note that the order of the series of processes in steps S202 to S204 and the series of processes in steps S205 to S207 is arbitrary. That is, steps S205 to S207 may be executed first. Further, step S204 and step S207 may be common steps, and output at the time of connection and disconnection may be performed simultaneously.

  When noise information is measured according to the procedure described above, if the electrical device to be measured is an electrical device that is a noise source (an electrical device that generates a large amount of noise), the electrical device is disconnected from the connected state. The amount of noise detected varies greatly depending on the state. By referring to this variation, it is possible to easily and quickly determine whether or not the electrical device to be measured is a noise source.

  In the procedure shown in FIG. 7, noise measurement was performed in two states, that is, when the electrical device to be measured was connected and when the electrical device was disconnected, but the noise was continuously measured for a certain period of time with the electrical device connected. Measurement may be performed. Since noise from an electric device fluctuates with time, it can be determined whether the noise is large enough to be a noise source.

  FIG. 8 shows a schematic functional block diagram of another example of the PLC modem functioning as the noise measuring apparatus according to the first embodiment of the present invention. The PLC modem 10 of FIG. 8 is the same as that of FIG. 3 except that the attenuation unit 8 is inserted between the variable signal transmission unit 4B and the coupling unit 5. In this PLC modem, since the level of the transmission signal from the modulation signal transmission unit 4B can be reduced, even if the level of noise mixed in the power line is small, the influence of noise on the signal received by the modulation signal reception unit 6B increases. It is also possible to identify electrical equipment that is a small noise source.

  The attenuation amount of the attenuator 8 is variable, and can be set to a level that is most easily detected according to the noise level of the electric device. Further, when used as an ordinary PLC modem, power line communication is not affected by setting the actual attenuation amount to zero.

(Second Embodiment)
FIG. 9 shows a schematic functional block diagram of an example of the noise measuring apparatus according to the second embodiment of the present invention. The noise measuring device in FIG. 9 includes a first power line communication device that transmits a power line communication signal and a second power line communication device that receives a power line communication signal.

  The measurement apparatus of FIG. 9 includes a first PLC modem 51, a second PLC modem 52, and a personal computer 50, which are examples of a power line communication apparatus. The first PLC modem 51, the second PLC modem 52, and the personal computer 50 may be housed in separate housings or in the same housing.

  The first PLC modem 51 and the second PLC modem 52 are connected to the table tap 70 via power cables 61 and 62, respectively. The power cable 71 of the table tap 70 is connected to the outlet 2 (in FIG. Connected to outlet C41) to which N2 is connected. Note that the power strips 61 and 62 may be connected together to one power plug so that a table tap is not necessary. Further, the plugs of the power cables 61 and 62 may be directly connected to the outlet 2.

  The personal computer 50 functions as a control device that controls the entire measuring apparatus. At the time of noise measurement, the personal computer 50 instructs the first PLC modem 51 to transmit a power line communication signal for measuring the state of noise in the power line communication, and also notifies the second PLC modem 52 of the power line communication signal. And calculation of noise information in power line communication based on the received power line communication signal.

  Further, the first PLC modem 51 generates and transmits a power line communication signal for measuring the noise state in the power line communication based on an instruction from the personal computer 50, and the second PLC modem 52 Based on the instruction of the computer 50, the reception of the power line communication signal and the calculation of noise information in the power line communication based on the received power line communication signal are performed. The generation and transmission of the power line communication signal is basically the same as the processing performed by the modulation signal generation unit 4A and the modulation signal transmission unit 4B in FIG. Also, the reception of the power line communication signal and the calculation of noise information in the power line communication based on the received power line communication signal are basically the same as the processing performed by the modulation signal demodulation unit 6A and the modulation signal reception unit 6B in FIG. Detailed description will be omitted.

  FIG. 10 is a block diagram showing an example of hardware of the PLC modem 10 constituting the measuring apparatus shown in FIG. As is apparent from the figure, the PLC modem of FIG. 10 is the same as the PLC modem of FIG. 5 except that the main IC 11 is provided with one PLC / MAC block 11C and one PLC / PHY block 11B. . Therefore, the PLC / MAC block 11C and the PLC / PHY block 11B are used for both transmission and reception. Except for this point, there is no difference in operation, and the description is omitted.

  Moreover, since the outline procedure which investigates the influence which the electric equipment connected to electric power wiring has on electric power line communication using this measuring apparatus is the same as the procedure shown in FIG. 7, description is abbreviate | omitted.

  FIG. 11 shows a schematic functional block diagram of another example of the noise measuring apparatus according to the second embodiment of the present invention. The noise measuring apparatus in FIG. 11 is the same as the noise measuring apparatus in FIG. 9 except that an attenuator 80 is inserted in the power cable 51 of the first PLC modem 51. As described above, the level of the power line communication signal to be transmitted can be reduced by inserting the attenuator 80. Therefore, even if the level of noise mixed in the power line is small, the signal received by the modulation signal receiving unit 6B can be reduced. The influence of noise is increased, and an electrical device that is a small noise source can be identified.

(Noise measurement example)
12 to 13 show the results of noise measurement using the noise measurement apparatus according to the second embodiment of the present invention. As shown in FIG. 2, this result is a result of measurement by connecting a noise measuring device to the outlet C41 and changing the connection of the electrical equipment. In the figure, the horizontal axis is a carrier number in multi-carrier communication and corresponds to a frequency. The vertical axis represents CINR (Carrier to Interference and Noise Ratio). In the figure, the line indicated by the symbol X is the CINR when the signal level is maximum, the line indicated by the symbol Y is the CINR when the signal level is minimum, and the line indicated by the symbol Z is the CINR measured during a certain period.

  In FIG. 12, the electric devices N2 and N3 are disconnected (non-operating), and the electric device N1 (electric device with a large noise generation) is operating (FIG. 12 (a)) and not operating (FIG. 12 (b)). It is the result measured by. As apparent from FIG. 12, although there is a slight difference, there is no difference between during operation and during non-operation. This indicates that there is little influence even if there is a noise generation source in the power wiring with different child breakers. Therefore, in the noise measurement, it is not necessary to consider the influence of the electric equipment connected to the power wiring connected to different child breakers.

  FIG. 13 shows measurement results when the operating states of the electric devices N2 and N3 connected to the power wiring L21 are changed. FIG. 13A shows the result when both the electric devices N2 and N3 are inactive. FIG. 13B shows the result when the electric device N2 is inactive and N3 is in operation. FIG. FIG. 13 (d) shows the result when both the electric devices N2 and N3 are operated, as a result when the electric device N2 is operated and N3 is not operated.

  When there are electrical devices N2 and N3 that are a plurality of noise sources, even if the magnitude of the noise is approximately N2 = N3, the effect is greater when they are connected to the same outlet. As described above, when the outlet connected to the power wiring connected to the same-phase identical child breaker is used, it is possible to identify the electrical device that becomes the noise source.

  INDUSTRIAL APPLICABILITY The present invention is useful as a method for easily and surely investigating the influence of electrical equipment connected to a power line on power line communication, and a noise measuring device for that purpose.

The figure which shows schematic structure of the example of wiring of the electric power supply to the indoor where the influence investigation method of this invention is applied The figure which shows an example of the connection state of a noise measuring device in the case of implementing the influence investigation method of this invention 1 is a schematic functional block diagram of an example of a PLC modem that functions as a noise measurement device according to a first embodiment of the present invention. The figure which shows the external appearance of the PLC modem of the 1st Embodiment of this invention The block diagram which shows an example of the hardware of the PLC modem of the 1st Embodiment of this invention The figure which shows schematic operation | movement flow in the case of measuring the state of the noise mixed in a power line using the PLC modem of the 1st Embodiment of this invention. The figure which shows the general | schematic procedure which investigates the influence which an electric equipment has on power line communication using the PLC modem of the 1st Embodiment of this invention. Schematic functional block diagram of another example of a PLC modem functioning as a noise measuring device according to the first embodiment of the present invention The figure which shows the schematic functional block diagram of an example of the noise measuring apparatus of the 2nd Embodiment of this invention. The block diagram which shows an example of the hardware of the PLC modem which comprises a part of noise measurement apparatus of the 2nd Embodiment of this invention The figure which shows the schematic functional block diagram of the other example of the noise measuring apparatus of the 2nd Embodiment of this invention. The figure which shows an example of the result of having performed noise measurement using the noise measuring apparatus of the 2nd Embodiment of this invention. The figure which shows the other example of the result of having performed noise measurement using the noise measuring apparatus of the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1A ... Power line 1B ... Power supply cable 2 ... Outlet 3 ... Control part 4A ... Modulation signal generation part 4B ... Modulation signal transmission part 5 ... Coupling part 6A ... Modulation signal Demodulator 6B ... Modulated signal receiver 7 ... Display 8 ... Attenuator 10 ... PLC modem 11 ... Main IC
11A ... CPU
11B, 11B1, 11B2 ... PLC / PHY block 11C, 11C1, 11C2 ... PLC / MAC block 12 ... AFE / IC
12A ... DA converter (DAC)
12B, 12C ... Variable amplifier (VGA)
12D AD converter (ADC)
13 ... Low-pass filter 15 ... Driver IC
16 ... coupler 16A ... coil transformer 16B, 16C ... coupling capacitor 17 ... band pass filter 18 ... memory 19 ... Ethernet PHY / IC
DESCRIPTION OF SYMBOLS 20 ... Switching power supply 21 ... Power supply connector 22 ... Modular jack 23 ... Display part 23A, 23B, 23C ... LED
24 ... AC / DC converter 25 ... Power plug 26 ... LAN cable 27 ... Impedance upper 27A, 27B ... Coil 30 ... Circuit module 40 ... Personal computer 50 ... Personal Computer 51 ... First PLC modem 52 ... Second PLC modem 61, 62, 71 ... Power cable 70 ... Table tap 80 ... Attenuator 100 ... Case 101 ...・ Changeover switch BB ... Distribution board (breaker box)
AB ... Main breaker (ampere breaker)
ELCB ... Earth leakage breaker B11, B12, B13, B21, B22, B23 ... Child breaker (safety breaker)
L11, L12, L13 ... Power wiring (L1 phase wiring)
L21, L22, L23 ... Power wiring (L2 phase wiring)
R1, R2, R3, R4 ... Chamber C11, C21, C22, C31, C32, C41, C42 ... Outlet N1, N2, N3 ... Electrical equipment (large noise generation)
S1, S2, S3 ... Electric equipment (small noise generation)
PLCA, PLCB ... PLC modem PCA, PCB ... Personal computer

Claims (20)

An impact investigation method for investigating the influence of electrical equipment connected to a power line on power line communication,
A transmission step of transmitting a power line communication signal by connecting the first power line communication device to a power wiring supplied with power in phase with the power supplied to the power wiring to which the electrical device is connected;
A receiving step of receiving the power line communication signal by a second power line communication device connected to the power wiring;
A noise information calculating step of calculating noise information in power line communication based on the power line communication signal received in the receiving step. An impact investigation method according to claim 1,
The first power line communication device is an influence investigation method connected to a power wiring connected to the same circuit breaker as the power wiring to which the electric device is connected. An impact investigation method according to claim 2,
An influence investigation method in which the first power line communication device is connected to the same outlet. An impact investigation method according to any one of claims 1 to 3,
And a noise information output step for outputting the noise information calculated in the noise information calculation step. An impact investigation method according to claim 4,
The noise information calculation step calculates the noise information based on the power line communication signal in a predetermined period during which the electric device is operating,
The noise information output step is an influence investigation method for outputting a temporal variation of the noise information. An influence investigation method according to any one of claims 1 to 4,
The noise information calculating step is an influence investigating method in which the noise information is calculated based on the power line communication signal during operation of the electric device and the power line communication signal during non-operation. An impact investigation method according to any one of claims 1 to 6,
The first power line communication device and the second power line communication device are configured by a single power line communication device including a transmission unit that transmits a power line communication signal and a reception unit that receives a power line communication signal. Investigation method that can be operated at the same time. An impact investigation method according to any one of claims 1 to 6,
The first power line communication device and the second power line communication device are connected to the same computer,
The first power line communication device executes the transmission step based on an instruction from the computer,
The influence investigation method in which the second power line communication device executes the reception step and the noise information calculation step based on an instruction from the computer. An impact investigation method according to any one of claims 1 to 8,
The noise information calculation step is an influence investigation method for calculating a ratio between a transmission rate of the power line communication signal or a signal level of the power line communication signal and noise. A noise measuring device for measuring a state of noise mixed in a power line performing power line communication,
A signal generator for generating a first power line communication signal having a predetermined output;
A coupling unit that is connected to a line that can be connected to the power line, and that passes a signal in a frequency band including a frequency band of the first power line communication signal;
A noise measurement comprising: a noise state detection unit that detects a state of noise from the line based on a second power line communication signal obtained by superimposing the first power line communication signal and a signal that has passed through the coupling unit. apparatus. The noise measuring device according to claim 10,
Furthermore, an attenuation unit that attenuates the power line communication signal is provided,
The attenuation unit is a noise measuring device connected between the signal generation unit and the coupling unit. The noise measuring device according to claim 11,
A noise measuring device capable of changing an attenuation amount of the attenuation unit. The noise measuring device according to any one of claims 10 to 12, further comprising:
A noise measurement device comprising a noise information output unit that outputs temporal fluctuations of a noise state detected by the noise state detection unit. The noise measuring device according to any one of claims 10 to 13,
The noise detection unit is a noise measurement device that calculates a transmission rate of the power line communication signal or a ratio between a signal level of the power line communication signal and noise. A noise measuring device for measuring a state of noise mixed in a power line performing power line communication,
A first power line communication device connected to the power line and capable of transmitting at least a power line communication signal;
A second power line communication device connected to the power line and capable of receiving at least a power line communication signal;
A control device that is connected to the first power line communication device and the second power line communication device and controls measurement of a state of noise mixed in the power line;
The control device instructs the first power line communication device to transmit a power line communication signal for measuring a noise state in the power line communication, and provides power line communication to the second power line communication device. Instructing the calculation of noise information in power line communication based on the reception of the signal and the received power line communication signal,
The first power line communication device generates and transmits a power line communication signal for measuring a noise state in power line communication based on an instruction from the control device,
The second power line communication device is a noise measurement device that receives a power line communication signal and calculates noise information in power line communication based on the received power line communication signal based on an instruction from the control device. The noise measuring device according to claim 15,
The power measuring cable for the first power line communication device and the power cable for the second power line communication device are connected to a single power plug. The noise measuring device according to claim 15 or 16,
Furthermore, an attenuator that attenuates the power line communication signal is provided,
The attenuator is a noise measuring device inserted in a power supply line of the first power line communication device. The noise measuring device according to claim 17,
A noise measuring device capable of changing an attenuation amount of the attenuation unit. The noise measuring device according to any one of claims 15 to 18, further comprising:
A noise measurement device comprising a noise information output unit that outputs a temporal variation in a noise state detected by the second power line communication device. The noise measuring device according to any one of claims 15 to 19,
The second power line communication device is a noise measurement device that calculates a transmission rate of the power line communication signal or a ratio between a signal level of the power line communication signal and noise.

Images