JP2005311412A - Line state detecting apparatus, and transmitter and receiver in balanced transmission system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a line state detecting apparatus capable of detecting a balanced state of a transmission line and to provide a transmitter and a receiver for a balanced transmission system capable of controlling the balanced state in response to a detection result so as to enhance the balance. <P>SOLUTION: The line state detecting apparatus provided to a balanced transmission system includes: current transformers T11, T12 whose primary sides respectively inserted in series with the transmission line comprising a pair of conductors W1, W2 connected to a transmission section 13 and whose secondary sides are connected in series with each other so as to cancel currents or voltages of both the current transformers; and a detection section 11 for detecting the current or the voltage of the secondary side of the current transformers T11, T12. An output of the detection section 11 provides a difference between the currents or the voltages across the conductors W1, W2 of the transmission line so as to detect an unbalanced component between the conductors W1, W2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a line state detection device that detects a state of a transmission line in a balanced transmission system that performs data transmission using a pair of conductors, and a transmission device and a reception device of a balanced transmission system including the same.

  Conventionally, balanced transmission systems that perform data transmission using a pair of transmission lines in a balanced state have been widely used. In this type of balanced transmission system, a transmission line such as a dedicated communication line is often used, such as a telephone line, and a certain degree of balance is usually maintained.

  An example of the transmission part and transmission line of the conventional balanced transmission apparatus is shown in FIG. This balanced transmission device is configured to send a signal from a transmission unit 92 to a transmission line including a pair of conductors W1 and W2 via a transmission transformer T91. At this time, the current of the transmission signal transmitted from the transmission unit 92 depends on the characteristics of the transmission unit 92 and the transmission lines W1 and W2.

  The transmission line from the transmission unit to the reception unit is originally required to be perfectly balanced, but in reality, it is connected to the unbalanced elements in the transmission unit and the reception unit, the wiring conditions of the transmission line, and the middle. In reality, the current flowing through the conductors W1 and W2 of the transmission line is not completely balanced. When the current flowing through the transmission line is unbalanced in this way, a part of the transmission power leaks from the transmission line to the outside, so that the data transmission characteristics deteriorate and problems such as interference occur.

  Recently, a balanced transmission system has been proposed in which data transmission is performed by superimposing a high-frequency signal on a power line carrying power such as a commercial power source. In particular, since such a power line is not originally a communication line, the degree of balance may vary depending on the wiring situation in each house, equipment connected to the power source, and the like. For this reason, when a power line is used as a transmission line, the degree of balance may vary depending on each environment, and transmission characteristics may vary greatly.

  Therefore, in a balanced transmission system, it is preferable to improve the balance of the transmission line by detecting the state of the transmission line and controlling the current or voltage in the two lines. Detection and control were not done.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a line state detection device capable of detecting a balanced state of a transmission line in a balanced transmission system.

  Another object of the present invention is to provide a transmission device and a reception device for a balanced transmission system that can control the balanced state of the transmission line based on the detection result in the balanced transmission system and can improve the balance. To do.

The line state detection device of the present invention is a line state detection device that detects the state of a transmission line in a balanced transmission system that performs data transmission using a pair of conductors, and directly detects an unbalanced component between the pair of conductors. An unbalanced component detecting means is provided.
This makes it possible to detect an unbalanced state such as a current or voltage unbalanced component in the transmission line. For example, the degree of balance can be improved by controlling the balanced state of the transmission line based on the detection result.

Moreover, it is said line | wire state detection apparatus as 1 aspect of this invention, Comprising: The said pair of conductor shall be a power line.
Thereby, in a balanced transmission system using a power line as a transmission line, it is possible to detect an unbalanced state such as an unbalanced component of a current or voltage in the transmission line.

Also, as one aspect of the present invention, in the line state detection device described above, the unbalanced component detection means includes a primary winding inserted in series in each of the pair of conductors, and a secondary winding thereof. A current transformer connected in series with each other and a detection unit for detecting a current or voltage of the secondary winding connected in series, wherein the secondary winding of the current transformer cancels the current or voltage in both transformers It shall be connected as follows.
As a result, it is possible to extract the difference between the forward and return currents in the pair of conductors using the current transformer, and to directly detect the unbalanced state in the transmission line.

Further, as one aspect of the present invention, in the line state detection device described above, the unbalanced component detection unit includes a first and a second winding inserted in series in each of the pair of conductors, A common mode coil having a third winding for common mode detection and a detection unit for detecting a voltage or current induced in the third winding are included.
As a result, it is possible to extract the difference between the forward and backward currents in the pair of conductors using the common mode coil, and directly detect the unbalanced state in the transmission line.

In addition, the power connection device of the present invention is used in a line state detection device that detects a state of a transmission line in a balanced transmission system that performs data transmission using a pair of conductors, and directly detects an unbalanced component between the pair of conductors. A power supply connection device including an unbalanced component detecting means for detecting, wherein the unbalanced component detecting means includes a first mode and a second winding inserted in series in each of the pair of conductors, and common mode detection. A common mode coil having a third winding is provided. This power connection device can be applied to an inlet or plug for power connection.
As a result, the unbalanced component between the pair of conductors can be detected by the common mode coil, and by using such a power supply connection device, the unbalanced component can be easily detected while saving space, and the power line can be connected. When used for a transmission line, the detection portion can be arranged at a position closest to the transmission line, and detection can be performed with high accuracy.

Moreover, as one aspect of the present invention, in the above-described line state detection device, the unbalanced component detection unit includes an impedance provided between the pair of conductors, and a current or voltage between a midpoint of the impedance and the ground. And a detecting unit for detecting.
This makes it possible to extract the difference in current or voltage in a pair of conductors using the impedance of a resistor, transformer, coil, etc. provided between the pair of conductors, and to directly detect an unbalanced state in the transmission line. Become.

Further, as one aspect of the present invention, the line state detection device described above includes a detection transformer in which a primary winding is inserted between a midpoint of the impedance and a ground, and the detection unit includes the voltage detection It shall detect the current or voltage of the secondary winding of the transformer.
Thus, when an unbalanced component is detected using an impedance provided between a pair of conductors, the unbalanced state in the transmission line is detected in a state where the transmission line and the detection unit are separated via the detection transformer. Is possible.

Moreover, as one aspect of the present invention, in the line state detection device described above, the impedance also serves as a termination impedance of the transmission line.
Thereby, it is possible to reduce the number of parts and reduce the cost.

Also, as one aspect of the present invention, in the above-described line state detection device, the transmission line is connected to a transmission device or a reception device via a transmission transformer, and the unbalanced component detection means is the transmission device. An impedance connected to the midpoint of the transmission line side winding of the transformer, and a voltage detection unit that detects a voltage between the impedance and the ground are included.
Thereby, using the transmission transformer to be inserted into the transmission line and the impedance connected to the midpoint of the transmission line side winding of the transmission transformer, it is possible to extract the difference between the currents or voltages in the pair of conductors. It is possible to directly detect the unbalanced state at.

Also, as one aspect of the present invention, in the above-described line state detection device, the transmission line is connected to a transmission device or a reception device via a transmission transformer, and the unbalanced component detection means is the transmission device. It is assumed that a detector for detecting a current or voltage between the midpoint of the winding on the transmission line side of the transformer and the ground is included.
As a result, the current or voltage difference between the pair of conductors can be extracted by detecting the current or voltage between the midpoint of the transmission line side winding of the transmission transformer to be inserted into the transmission line and the ground. It becomes possible to directly detect the equilibrium state.

Also, as one aspect of the present invention, the line state detection device described above, including a detection transformer in which a primary winding is inserted between the midpoint of the transmission line side winding of the transmission transformer and the ground, The detection unit detects the current or voltage of the secondary winding of the detection transformer.
As a result, when the unbalanced component is detected using the midpoint of the transmission transformer inserted into the transmission line, the unbalanced state in the transmission line is maintained with the transmission line and the detection unit being separated via the detection transformer. It becomes possible to detect.

Moreover, as one aspect of the present invention, in the above-described line state detection device, the unbalanced component detection means calculates the magnitude and direction of the unbalanced component between the pair of conductors.
This makes it possible to detect the direction along with the magnitude of the unbalanced component in the transmission line.

Further, as one aspect of the present invention, in the above-described line state detection device, the unbalanced component detection unit includes a transmission signal output to the conductor and a difference current or voltage between a forward path and a return path in the conductor. Phase comparison shall be performed.
Thus, the direction of the unbalanced component in the transmission line can be detected by phase comparison between the transmission signal sent to the conductor and the current or voltage of the difference between the forward path and the return path in the conductor.

Further, as one aspect of the present invention, in the above-described line state detection device, the unbalanced component detection unit includes a transmission signal output to the conductor and a difference current or voltage between a forward path and a return path in the conductor. The product shall be calculated.
Thus, the direction and magnitude of the unbalanced component in the transmission line can be detected by the product of the transmission signal sent to the conductor and the current or voltage of the difference between the forward path and the return path in the conductor.

According to another aspect of the present invention, there is provided the line state detection apparatus as described above, wherein the transmission signal output to the conductor is adjusted to adjust a phase of at least one of a difference current or voltage between a forward path and a return path in the conductor. Compensation means shall be provided.
Thereby, it is possible to accurately detect the direction of the unbalanced component in the transmission line by performing phase comparison or product calculation after adjusting the phase shift by the phase shift means.

The transmission device of the present invention is a transmission device used in a balanced transmission system that performs data transmission using a pair of conductors, and includes a transmission-side line state detection device including any one of the above-described line state detection devices.
Thereby, in the transmission device, it becomes possible to detect an unbalanced state such as an unbalanced component of current or voltage in the transmission line. For example, the degree of balance can be improved by controlling the balanced state of the transmission line based on the detection result.

Further, as one aspect of the present invention, the transmission device includes a transmission signal control unit that controls a transmission signal output to the conductor based on an output of the transmission-side line state detection device.
As a result, by controlling the transmission signal output to the conductor based on the detection result of the unbalanced state in the transmission line detected by the line state detection device, the unbalanced component of the transmission line can be reduced, and the degree of balance can be reduced. It becomes possible to improve.

A receiving apparatus according to the present invention is a receiving apparatus used in a balanced transmission system that performs data transmission using a pair of conductors, the receiving-side line state detecting apparatus including any one of the above-described line state detecting apparatuses, and the receiving-side line. And a line state output unit that outputs a state detection signal indicating the line state of the transmission line based on the output of the state detection device.
As a result, the receiving device can detect an unbalanced state such as an unbalanced component of the current or voltage in the transmission line. For example, the degree of balance can be improved by transmitting the detection result to the transmission side and controlling the balanced state of the transmission line.

The transmission device of the present invention is a transmission device used in a balanced transmission system that performs data transmission using a pair of conductors, and is a transmission that outputs to the conductor based on the state detection signal output from the reception device. A transmission signal control unit for controlling the signal is provided.
Thus, by controlling the transmission signal output to the conductor based on the state detection signal detected by the receiving device, it is possible to reduce the unbalanced component of the transmission line and improve the balance.

A balanced transmission system according to the present invention is a balanced transmission system that performs data transmission using a pair of conductors, and includes a transmission-side line state detection device including any one of the above-described line state detection devices, and transmission output to the conductors. A transmission device including a transmission signal control unit for controlling a signal, a reception-side line state detection device including any one of the above-described line state detection devices, and a line of the transmission line based on an output of the reception-side line state detection device And a line state output unit that outputs a state detection signal indicating a state, and the transmission signal control unit is configured to output the state of the transmission side line state detection device and the state detection output from the reception device. The transmission signal output to the conductor is controlled based on the signal.
As a result, by controlling the transmission signal output to the conductor based on the detection result of the unbalanced state in the transmission line detected by the line state detection device, the unbalanced component of the transmission line can be reduced, and the degree of balance can be reduced. It becomes possible to improve.

  ADVANTAGE OF THE INVENTION According to this invention, the line state detection apparatus which can detect the balanced state of a transmission line can be provided in a balanced transmission system. Further, in the balanced transmission system, it is possible to provide a transmission device and a receiving device of the balanced transmission system that can control the balanced state of the transmission line based on the detection result and can improve the degree of balance.

  In an embodiment of the present invention, a line state detection device that detects a state of a transmission line in a balanced transmission system that performs data transmission through a balanced transmission line, and a transmitter and a receiver of a balanced transmission device that includes this line state detection device, In addition, a configuration example of a balanced transmission system having both the transmitter and the receiver is shown. The line state detection apparatus of this embodiment is applicable to a balanced transmission system such as a power line communication system using a power line as a transmission line. Moreover, as data communication, it is used suitably for data communication, such as power line communication which uses a frequency division multiplexing signal, OFDM (Orthogonal Frequency Division Multiplexing), or ADSL (Asymmetric Digital Subscriber Line).

  First, the outline | summary of the transmitter and receiver of the balanced transmission apparatus which concerns on embodiment of this invention, and a balanced transmission system is demonstrated.

  FIG. 1 is a diagram showing a schematic configuration of a transmitter of a balanced transmission apparatus according to an embodiment of the present invention. The transmitter 1 includes a line state detection device 2 that detects a state of a balanced transmission line composed of a pair of conductors W1 and W2 that are signal transmission lines, and a transmission unit that inputs transmission signal data and transmits a transmission signal. 3.

  The transmission signal output from the transmission unit 3 is sent to the conductors W1 and W2 via the line state detection device 2. The signals injected into the conductors W1 and W2 may be different from the values output from the transmitter 3 depending on the transmission impedance and transmission path impedance of the transmitter. The line state detection device 2 detects the current or voltage flowing through the conductors W1 and W2, or both levels, calculates a state detection signal indicating an unbalanced state of the transmission line, and feeds it back to the transmission unit 3. The transmission unit 3 has a function of a transmission signal control unit, and based on the fed back state detection signal, the transmission signal to be output is improved so that the balance of the signals actually transmitted to the conductors W1 and W2 is improved. Control level, ie current or voltage, or both.

  Thus, by detecting the balanced state of the transmission line at the transmitter and controlling the current or voltage of the signal sent to the transmission line, or both, the conductors W1 and W2 are actually connected to the conductors W1 and W2 according to the state of the transmission line. The transmission signal level to be transmitted can be adjusted, the common mode signal level in the transmission line can be reduced, and the balance seen from the transmitter can be improved.

  FIG. 2 is a diagram showing a schematic configuration of the receiver of the balanced transmission apparatus according to the embodiment of the present invention. The receiver 4 receives a transmission signal from the conductors W1 and W2 and outputs signal data by receiving a transmission line from the conductors W1 and W2 and a line state detection device 5 that detects the state of the balanced transmission line made up of a pair of conductors W1 and W2 that are signal transmission paths. And the receiving unit 6 that is configured. Further, the transmitter 1 has a configuration including a transmission unit 3 connected to the conductors W1 and W2 of the balanced transmission line.

  The transmission signal transmitted through the conductors W1 and W2 is input to the line state detection device 5. The line state detection device 5 detects the level of current and / or voltage flowing in from the conductors W1 and W2, or both levels, calculates a state detection signal indicating an unbalanced state of the transmission line, and sends the transmission unit 3 via the reception unit 6. To give feedback. At this time, the unbalanced component has a value as if the same signal was combined as a bias in each of the conductors W1 and W2, and thus this bias value is detected. The transmission unit 3 has a function of a transmission signal control unit. Based on the state detection signal fed back from the reception unit 6, for example, the level of the transmission signal to be output is reduced so that the bias value of the fed back in-phase component is reduced. Control.

  In this way, the balanced state of the transmission line is detected by the receiver, and by controlling the current or voltage of the signal sent to the transmission line or the signal flowing in from the transmission line, or both, according to the state of the transmission line, The reception signal level actually transmitted from the conductors W1 and W2 can be adjusted, the common mode signal level in the transmission line can be reduced, and the balance seen from the receiver can be improved.

  FIG. 3 is a diagram showing a schematic configuration of a balanced transmission system including a transmitter and a receiver according to the embodiment of the present invention. This balanced transmission system includes a transmitter 1 including a line state detection device 2 and a transmission unit 3, and a receiver 4 including a line state detection device 5 and a reception unit 6, and a pair of conductors W1 serving as signal transmission paths. , W2 is used for balanced data transmission.

  The signal data for transmission is input to the transmission unit 3 and output as a transmission signal, and is transmitted to the conductors W1 and W2 via the line state detection device 2. At this time, the signal level sent to the conductors W <b> 1 and W <b> 2 is detected by the line state detection device 2, and a state detection signal indicating an unbalanced state of the transmission line is calculated and fed back to the transmission unit 3. In the transmission unit 3, the level of the transmission signal to be output is adjusted based on the state detection signal, and is controlled so that the balance of the signals sent to the conductors W1 and W2 is improved.

  Further, the transmission signal transmitted through the conductors W1 and W2 is received by the receiving unit 6 through the line state detection device 5, and signal data is acquired and output. At this time, the signal level transmitted on the conductors W1 and W2 is detected by the line state detection device 5, and a state detection signal indicating an unbalanced state of the transmission line is calculated and fed back to the transmission unit 3 via the reception unit 6. The In the transmission unit 3, the level of the transmission signal to be output is adjusted based on the state detection signal, and thereby, the balance of the signal received by the reception unit 6 via the conductors W1 and W2 is controlled to be improved.

  Thus, by detecting the balanced state of the transmission line at the transmitter and the receiver, and controlling the current or voltage of the signal on the transmission line, or both, the transmission signal on the conductors W1 and W2 according to the state of the transmission line The level can be adjusted, the common mode signal level in the transmission line can be reduced, and the balance seen from both the transmitter and the receiver can be improved.

  Next, some embodiments of the line state detection device of the present invention used in the transmitter and receiver of the balanced transmission device and the balanced transmission system as described above will be described. The line state detection apparatus according to the present embodiment detects a state related to the balance of the transmission line by directly detecting the voltage or current in the pair of conductors constituting the transmission line, or both unbalanced components. . In the following embodiment, a line state detection device applied to a transmitter is exemplified, but the same can be applied to a receiver.

(First embodiment)
FIG. 4 is a diagram illustrating a basic configuration of the line state detection device according to the first embodiment of the present invention. In the line state detection device according to the present embodiment, the primary side (primary winding) is inserted in series in each of the transmission line on the forward path side and the return path side including the pair of conductors W1 and W2 connected to the transmission unit 13. Current transformers T11 and T12 are provided. The secondary sides (secondary windings) of these current transformers T21 and T22 are connected in series so as to cancel the current or voltage in both transformers. Moreover, it has the detection part 11 which detects the electric current or voltage of the secondary side of current transformer T11, T12, and is comprised.

  In this configuration, the detection unit 11 can directly detect a common mode current (unbalanced current) that is a difference between the forward and return currents of the transmission line conductors W1 and W2 in a state separated from the transmission line. Therefore, it is possible to detect the unbalanced component of the transmission power from the transmission unit 13 with a simple configuration.

  FIG. 5 shows a first modification of the line state detection device according to the first embodiment. This first modification is a configuration in which one conductor W1 or W2 (W2 in the example in the figure) of the transmission line and the transmission unit 13 are connected to the detection unit 11 in the configuration of FIG. In this configuration, the detection unit 11 detects a current or voltage on the secondary side of the current transformers T11 and T12 and transmits a part of the transmission signal transmitted from the transmission unit 13 or the transmission signal transmitted through the conductor W1 or W2. , And the phase of the transmission signal or the signal transmitted through the conductor W1 or W2 and the current and / or voltage of the unbalanced component in the conductors W1 and W2 are compared. Thereby, the direction of the unbalanced current can be detected along with the magnitude of the unbalanced component between the conductors W1 and W2. Note that when the detection unit 11 compares the phases, the phase of one or both of the currents or voltages in the conductors W1 and W2 may be used instead of the transmission signal.

  5, the current or voltage of the unbalanced component in the conductors W1 and W2 detected by the detection unit 11 and the current or voltage of the transmission signal or the conductor W1 or W2 extracted from the transmission unit 13 The product may be calculated by the detection unit 11. Accordingly, the amount of unbalanced component between the conductors W1 and W2 of the transmission line can be detected by the calculated value of the product, and the direction of the unbalanced current can be detected by the sign of the calculated value.

  FIG. 6 shows a second modification of the line state detection device according to the first embodiment. In the second modification, in the configuration of FIG. 4, a part of the transmission signal transmitted from the transmission unit 13 is input, and the phase of the current or voltage of the transmission signal is shifted and output to the detection unit 11. The circuit P11 is provided. The phase shift circuit P11 may be either one that performs an analog phase shift using a delay element or the like, or one that performs a digital phase shift process using a digital circuit. In this configuration, the phase shift circuit P11 performs phase compensation by advancing or delaying the phase of the transmission signal extracted from the transmission unit 13. The detection unit 11 detects the current or voltage on the secondary side of the current transformers T11 and T12 and inputs the transmission signal phase-compensated by the phase shift circuit P11, and the current or voltage of the unbalanced component in the conductors W1 and W2. And the product of the current or voltage of the transmission signal. Thereby, it is possible to accurately detect the value of the unbalanced component and the direction of the unbalanced current between the conductors W1 and W2 of the transmission line.

  FIG. 7 shows a third modification of the line state detection device according to the first embodiment. This third modification is a configuration provided with a phase shift circuit P12 that shifts the phase of the voltage or current of the unbalanced component of the conductor W1 or W2 of the transmission line and outputs it to the detection unit 11 in the configuration of FIG. The phase shift circuit P12 may be either one that performs an analog phase shift using a delay element or the like, or one that performs a digital phase shift process using a digital circuit. In this configuration, the phase shift circuit P12 performs phase compensation by advancing or delaying the phase of the detected voltage or current of the unbalanced component of the conductors W1 and W2. The detection unit 11 detects the current or voltage on the secondary side of the current transformers T11 and T12, and sends from the transmission unit 13 the current or voltage of the unbalanced component in the conductor W1 or W2 phase-compensated by the phase shift circuit P12. And a part of the transmission signal to be inputted, and the product of these is calculated. Thereby, it is possible to accurately detect the value of the unbalanced component and the direction of the unbalanced current between the conductors W1 and W2 of the transmission line.

  According to such a line state detection apparatus of the first embodiment, the primary side is inserted in series with each of the conductors W1 and W2 constituting the transmission line, and the secondary side cancels the currents or voltages of both transformers. By detecting the current or voltage on the secondary side of the current transformers T11 and T12 connected in series by the detection unit 11, the difference between the forward and return currents between the conductors W1 and W2, that is, the unbalanced component, is transmitted from the transmission line. It can be detected directly in the separated state.

  In addition, the detection unit 11 compares the phase of the current of the unbalanced component detected in the above configuration with a part of the current or voltage of the transmission signal extracted from the transmission unit 13 or calculates the product of both. The direction of the unbalanced current can be detected along with the value of the unbalanced component between the conductors W1 and W2 of the transmission line. Further, the phase of the transmission signal taken out from the transmitter 13 or the phase or voltage of the unbalanced component in the conductors W1 and W2 is compensated by the phase shift circuit, and the current and voltage of the unbalanced component in the conductors W1 and W2 are transmitted. By calculating the product with the signal, the direction and absolute amount of the unbalanced component in the transmission line can be accurately detected.

(Second Embodiment)
FIG. 8 is a diagram showing a basic configuration of a line state detection device according to the second embodiment of the present invention. In the line state detection device according to the present embodiment, the first and second windings are respectively connected to the conductors W1 and W2 in the transmission line on the forward path side and the return path side including the pair of conductors W1 and W2 connected to the transmission unit 23. The common mode coil L21 is inserted in series and includes a third winding for detecting the common mode. Further, by detecting the voltage or current at both ends of the third winding of the common mode coil L21, detection for detecting the unbalanced current or unbalanced voltage between the conductors W1 and W2 induced in the third winding. The unit 21 is configured.

  In this configuration, the detection unit 21 can directly detect the common mode current (unbalanced current) in the conductors W1 and W2 of the transmission line in a state separated from the transmission line. Therefore, it is possible to detect the unbalanced component of the transmission power from the transmission unit 23 with a simple configuration. Further, the configuration of the second embodiment is simpler than the configuration using the current transformer of the first embodiment, and the detection is based on the difference in detection accuracy caused by the characteristic variation between the two current transformers. Errors are reduced, and detection sensitivity and detection accuracy are improved.

  Note that the common mode coil L21 can also be used as a common mode coil for countermeasures against unwanted radiation interference that is normally provided in communication equipment and the like, so that the number of parts can be reduced and the cost can be reduced. By configuring the common mode coil L21 with a toroidal core, detection accuracy can be improved. The arrangement position of the common mode coil L21 is provided in the vicinity of the input / output portion of the transmission line in the transmitter or receiver, and the detection accuracy can be further improved by bringing it as close to the transmission line as possible.

  FIG. 9 is a diagram illustrating a configuration example in which a common mode coil is provided in an inlet connector for connecting a power cord of the apparatus in a power line communication system using a power line as a transmission line. The transmitter 1 is provided with an inlet connector 15 to which a plug 14 of a power cord incorporating the conductors W1 and W2 is detachably connected, and the conductors W1 and W2 and the transmitter 23 are connected via the inlet connector 15. It has come to be. The inlet connector 15 has a built-in common mode coil L21. Based on the output of the common mode coil L21, the detection unit 21 can detect an unbalanced current or voltage between the conductors W1 and W2. In addition to the inlet connector, a common mode coil may be provided in a power cord plug or the like.

  FIG. 10 shows a first modification of the line state detection device according to the second embodiment. This first modification is a configuration in which one conductor W1 or W2 (W2 in the example in the figure) of the transmission line or the transmission unit 23 is connected to the detection unit 21 in the configuration of FIG. In this configuration, the detection unit 21 detects the voltage or current at both ends of the third winding of the common mode coil L21 and transmits a part of the transmission signal transmitted from the transmission unit 23 or the conductor W1 or W2. The transmission signal is input, and the phase of the current and / or voltage of the unbalanced component in the conductors W1 and W2 detected by the third winding of the common mode coil L21 is compared with this transmission signal. Thereby, the direction of the unbalanced current can be detected along with the magnitude of the unbalanced component between the conductors W1 and W2. In addition, when the phase is compared in the detection part 21, you may use the phase of one or both the electric current or voltage in the conductors W1 and W2.

  10, the current or voltage of the unbalanced component in the conductors W1 and W2 detected by the third winding of the common mode coil L21 and the current or voltage of the transmission signal extracted from the transmission unit 23. The detection unit 21 may calculate the product of Accordingly, the amount of unbalanced component between the conductors W1 and W2 of the transmission line can be detected by the calculated value of the product, and the direction of the unbalanced current can be detected by the sign of the calculated value.

  FIG. 11 shows a second modification of the line state detection device according to the second embodiment. In the second modification, in the configuration of FIG. 8, a part of the transmission signal transmitted from the transmission unit 23 is input, and the phase of the current or voltage of the transmission signal is shifted and output to the detection unit 21. The circuit P21 is provided. The phase shift circuit P21 may be either one that performs an analog phase shift using a delay element or the like, or one that performs a digital phase shift process using a digital circuit. In this configuration, the phase shift circuit P21 performs phase compensation by advancing or delaying the phase of the transmission signal extracted from the transmission unit 23. The detection unit 21 detects the voltage or current at both ends of the third winding of the common mode coil L21, and inputs the transmission signal phase-compensated by the phase shift circuit P21, and the unbalanced component in the conductors W1 and W2 is detected. The product of the current or voltage and the current or voltage of the transmission signal is calculated. Thereby, it is possible to accurately detect the value of the unbalanced component and the direction of the unbalanced current between the conductors W1 and W2 of the transmission line.

  FIG. 12 shows a third modification of the line state detection device according to the second embodiment. This third modification is a configuration provided with a phase shift circuit P22 that shifts the phase of the voltage or current of the unbalanced component detected by the common mode coil L21 and outputs it to the detection unit 21 in the configuration of FIG. The phase shift circuit P22 may be either one that performs an analog phase shift using a delay element or the like, or one that performs a digital phase shift process using a digital circuit. In this configuration, the phase shift circuit P22 performs phase compensation by advancing or delaying the phase of the current or voltage of the unbalanced component detected by the common mode coil L21. The detection unit 21 detects the voltage or current at both ends of the third winding of the common mode coil L21, and from the unbalanced component current in the conductor W1 or W2 phase-compensated by the phase shift circuit P22 and the transmission unit 23 A part of a transmission signal to be transmitted is input and a product of these is calculated. Thereby, it is possible to accurately detect the value of the unbalanced component and the direction of the unbalanced current between the conductors W1 and W2 of the transmission line.

  According to such a line state detection apparatus of the second embodiment, the first and second windings are inserted into the conductors W1 and W2 constituting the transmission line, respectively, and the third winding for common mode detection is provided. By detecting the voltage or current at both ends of the third winding of the common mode coil L21 having a wire with the detection unit 21, the difference between the currents or voltages between the conductors W1 and W2, that is, the unbalanced component is detected from the transmission line. It can be detected directly in the separated state.

  Further, the detection unit 21 compares the phase of the current or voltage of the unbalanced component detected in the above configuration with a part of the current or voltage of the transmission signal extracted from the transmission unit 23, or calculates the product of both. Thus, the direction of the unbalanced current can be detected together with the value of the unbalanced component between the conductors W1 and W2 of the transmission line. Further, the phase of the current or voltage of the transmission signal taken out from the transmission unit 23 or the phase of the current or voltage in one of the conductors W1 and W2 is compensated by the phase shift circuit and detected by the common mode coil L21 in the conductors W1 and W2. By calculating the product of the unbalanced component current or voltage and the transmission signal, the direction and absolute amount of the unbalanced component in the transmission line can be accurately detected.

(Third embodiment)
FIG. 13 is a diagram showing a basic configuration of a line state detection device according to the third embodiment of the present invention. The line state detection device according to the present embodiment is inserted between the transmission line and the transmission unit 33 in the transmission line composed of a pair of conductors W1 and W2 connected to the transmission unit 33, and on the secondary side on the transmission line side. A transmission transformer T31 having a midpoint tap, an impedance Z31 inserted between the secondary midpoint tap of the transmission transformer T31 and the ground, and a detection unit 31 for detecting a voltage at both ends of the impedance Z31. Configured.

  In this configuration, the detection unit 31 can directly detect the common mode voltage (unbalanced voltage) at the conductors W1 and W2 of the transmission line by the voltage between the secondary side midpoint of the transmission transformer T31 and the ground potential. Therefore, it is possible to detect the unbalanced component of the transmission power from the transmission unit 33 with a simple configuration. In the configuration of the third embodiment, the configuration is further simplified by using a transmission transformer having a midpoint tap.

  FIG. 14 shows a first modification of the line state detection device according to the third embodiment. This first modification is a configuration in which one of the conductors W1 or W2 (W2 in the illustrated example) or the transmission unit 33 of the transmission line is connected to the detection unit 31 in the configuration of FIG. In this configuration, the detection unit 31 detects a voltage across the impedance Z31 and inputs a part of the transmission signal transmitted from the transmission unit 33 or a transmission signal transmitted through the conductor W1 or W2, and this signal and The phase of the voltage of the unbalanced component in the conductors W1 and W2 is compared. Thereby, the direction of the unbalanced voltage can be detected along with the magnitude of the unbalanced component between the conductors W1 and W2. In addition, when comparing the phase in the detection part 31, you may use the phase of the voltage of one or both in the conductors W1 and W2.

  In the line state detection apparatus of FIG. 14, the product of the voltage of the unbalanced component in the conductors W1 and W2 detected at the midpoint of the transmission transformer T31 and the voltage of the transmission signal extracted from the transmission unit 33 is detected by the detection unit 31. It is good also as a structure calculated in. Accordingly, the amount of unbalanced component between the conductors W1 and W2 of the transmission line can be detected by the calculated value of the product, and the direction of the unbalanced current can be detected by the sign of the calculated value.

  FIG. 15 shows a second modification of the line state detection device according to the third embodiment. In the second modification, a part of a transmission signal transmitted from a detection unit 31 that detects a voltage between the secondary side midpoint of the transmission transformer T31 and the ground potential and a transmission unit 33 is input, and the transmission signal And a phase shift circuit P31 that shifts the phase of the voltage and outputs it to the detector 31. The phase shift circuit P31 may be either one that performs an analog phase shift using a delay element or the like, or one that performs a digital phase shift process using a digital circuit. In this configuration, the phase shift circuit P31 performs phase compensation by advancing or delaying the phase of the transmission signal extracted from the transmission unit 33. The detection unit 31 detects the voltage between the secondary side midpoint of the transmission transformer T31 and the ground potential, and inputs the transmission signal phase-compensated by the phase shift circuit P31, and the unbalanced components in the conductors W1 and W2 are detected. The product of the voltage and the voltage of the transmission signal is calculated. Thereby, it is possible to accurately detect the value of the unbalanced component and the direction of the unbalanced current between the conductors W1 and W2 of the transmission line.

  FIG. 16 shows a third modification of the line state detection device according to the third embodiment. This third modification is configured to include a phase shift circuit P32 that shifts the phase of the unbalanced voltage of the transmission line taken out from the secondary side midpoint tap of the transmission transformer T31 and outputs the phase to the detection unit 31. The phase shift circuit P32 may be either one that performs an analog phase shift using a delay element or the like, or one that performs a digital phase shift process using a digital circuit. In this configuration, the phase shift circuit P32 performs phase compensation by advancing or delaying the phase of the voltage at the secondary midpoint of the transmission transformer T31. The detection unit 31 inputs the voltage between the secondary midpoint of the transmission transformer T31 phase-compensated by the phase shift circuit P32 and the ground potential, and a part of the transmission signal transmitted from the transmission unit 33. The product of is calculated. Thereby, it is possible to accurately detect the value of the unbalanced component and the direction of the unbalanced current between the conductors W1 and W2 of the transmission line.

  According to such a line state detection device of the third embodiment, the transmission is inserted between the transmission line composed of the conductors W1 and W2 and the transmission unit 33 and has a midpoint tap on the secondary side on the transmission line side. By detecting the potential of the secondary side midpoint using the transformer T31, the detection unit 31 can directly detect the difference in current or voltage between the conductors W1 and W2, that is, the unbalanced component, with a simple configuration. Can do.

  Further, the detection unit 31 compares the phase of the voltage of the unbalanced component detected in the above configuration with the voltage of the transmission signal extracted from the transmission unit 33, or calculates the product of the two, thereby calculating the conductor of the transmission line. The direction of the unbalanced current can be detected along with the value of the unbalanced component between W1 and W2. Further, the phase of the voltage of the transmission signal taken out from the transmitter 33 or the phase of the midpoint voltage of the conductors W1 and W2 is compensated by the phase shift circuit, and the product of the midpoint voltage of these conductors W1 and W2 and the transmission signal is compensated. By calculating the direction and absolute amount of the unbalanced component in the transmission line.

(Fourth embodiment)
FIG. 17 is a diagram showing a basic configuration of a line state detection device according to the fourth embodiment of the present invention. In the fourth embodiment, an unbalanced component is detected via a transformer in addition to the configuration of the third embodiment. The line state detection device of the present embodiment is inserted between the transmission line and the transmission unit 43 in the transmission line composed of a pair of conductors W1 and W2 connected to the transmission unit 43, on the secondary side on the transmission line side. A transmission transformer T41 having a midpoint tap, a detection transformer T42 in which a primary winding is connected between the secondary side midpoint tap of the transmission transformer T41 and the ground, and a secondary winding of the detection transformer T42. And a detection unit 41 that detects current or voltage.

  In this configuration, the detection unit 41 detects the voltage or voltage of the secondary side midpoint of the transmission transformer T41 and the ground potential by detecting the current or voltage of the secondary winding of the detection transformer T42. To detect through. Thereby, the common mode voltage (unbalanced voltage) in the conductors W1 and W2 of the transmission line, that is, the unbalanced component of the transmission power from the transmitter 43 can be detected in a state separated from the transmission line. In the configuration of the fourth embodiment, since the detection unit for detecting the unbalanced component is provided in a form separated from the transmission line, the influence of the detection unit on the transmission line can be eliminated, and the transmission line is more accurately detected. It is possible to detect an unbalanced component in.

  FIG. 18 shows a first modification of the line state detection device according to the fourth embodiment. The first modification is a configuration in which the transmission unit 43 is connected to the detection unit 41 in the configuration of FIG. In this configuration, the detection unit 41 detects the current or voltage of the secondary winding of the detection transformer T42, and inputs a part of the transmission signal transmitted from the transmission unit 43. The transmission signal and the conductor W1, Compare the phase of the current and / or voltage of the unbalanced component at W2. Thus, the magnitude of the unbalanced component between the conductors W1 and W2 and the direction of the unbalanced current can be detected in a state separated from the transmission line.

  18, the detection unit 41 calculates the product of the voltage of the unbalanced component in the conductors W1 and W2 detected by the detection unit 41 and the current or voltage of the transmission signal extracted from the transmission unit 43. It is good also as composition to do. Accordingly, the amount of unbalanced component between the conductors W1 and W2 of the transmission line can be detected by the calculated value of the product, and the direction of the unbalanced current can be detected by the sign of the calculated value.

  FIG. 19 shows a second modification of the line state detection device according to the fourth embodiment. In the second modification, in the configuration of FIG. 17, a part of the transmission signal transmitted from the transmission unit 43 is input, and the phase of the current or voltage of the transmission signal is shifted and output to the detection unit 41. The circuit P41 is provided. The phase shift circuit P41 may be either one that performs an analog phase shift using a delay element or the like, or one that performs a digital phase shift process using a digital circuit. In this configuration, the phase shift circuit P41 performs phase compensation by advancing or delaying the phase of the transmission signal extracted from the transmission unit 43. The detection unit 41 detects the current or voltage of the secondary winding of the detection transformer T42 and inputs the transmission signal phase-compensated by the phase shift circuit P41, and transmits the voltage and transmission of the unbalanced component in the conductors W1 and W2. Calculate the product of the signal current or voltage. As a result, the value of the unbalanced component and the direction of the unbalanced current between the conductors W1 and W2 of the transmission line can be accurately detected in a state where it is separated from the transmission line.

  FIG. 20 shows a third modification of the line state detection device according to the fourth embodiment. This third modification is a configuration provided with a phase shift circuit P42 that shifts the phase of the current or voltage of the secondary winding of the detection transformer T42 and outputs the phase to the detection unit 41 in the configuration of FIG. The phase shift circuit P42 may be either one that performs an analog phase shift using a delay element or the like, or one that performs a digital phase shift process using a digital circuit. In this configuration, the phase shift circuit P42 performs phase compensation by advancing or delaying the phase of the current or voltage in the secondary winding of the detection transformer T42. The detection unit 41 inputs the current or voltage of the secondary winding of the detection transformer T42 phase-compensated by the phase shift circuit P42 and a part of the transmission signal transmitted from the transmission unit 43, and calculates the product of these products. calculate. As a result, the value of the unbalanced component and the direction of the unbalanced current between the conductors W1 and W2 of the transmission line can be accurately detected in a state where it is separated from the transmission line.

  According to the line state detection device of the fourth embodiment as described above, the transmission is inserted between the transmission line composed of the conductors W1 and W2 and the transmission unit 43 and has the midpoint tap on the secondary side on the transmission line side. Current or voltage of the secondary winding of the detection transformer T42 using the transformer T41 for detection and the detection transformer T42 in which the primary winding is connected between the secondary side midpoint tap of the transmission transformer T41 and the ground. By detecting with the detection part 41, the difference of the electric current or voltage between the conductors W1 and W2, ie, an unbalance component, can be detected in the state isolate | separated from the transmission line.

  Further, in the detection unit 41, the phase of the current or voltage of the unbalanced component detected in the above configuration and a part of the current or voltage of the transmission signal extracted from the transmission unit 43 is compared, or the product of both is calculated. Thus, the direction of the unbalanced current can be detected together with the value of the unbalanced component between the conductors W1 and W2 of the transmission line. Further, the phase of the current or voltage of the transmission signal taken out from the transmitter 43 or the phase of the current or voltage at the midpoint of the conductors W1 and W2 is compensated by the phase shift circuit, and the current at the midpoint of these conductors W1 and W2 Alternatively, by calculating the product of the voltage and the transmission signal, the direction and absolute amount of the unbalanced component in the transmission line can be accurately detected.

(Fifth embodiment)
FIG. 21 is a diagram showing a basic configuration of a line state detection device according to the fifth embodiment of the present invention. The line state detection apparatus according to the present embodiment includes a transmission transformer T51 inserted between the transmission line and the transmission unit 53 in a transmission line including a pair of conductors W1 and W2 connected to the transmission unit 53, and a transmission. And two impedances Z51 and Z52 connected in series between the conductors W1 and W2 on the transmission line side of the transformer T51, and a detection unit 51 that detects the voltage between the connection part of the impedances Z51 and Z52 and the ground potential. Composed. By using two impedances Z51 and Z52 having substantially the same characteristic values, it is possible to obtain the same action as the midpoint of the transmission transformer shown in the third embodiment. The impedances Z51 and Z52 are not limited to resistors having a resistance component, and those having a reactance component may be used.

  In this configuration, the detection unit 51 detects the voltage at the intersection of the impedances Z51 and Z52, that is, the midpoint voltage of the conductors W1 and W2 of the transmission line, thereby detecting the common mode voltage (unbalanced) in the conductors W1 and W2 of the transmission line. Voltage) can be detected directly. Therefore, it is possible to detect the unbalanced component of the transmission power from the transmission unit 53 with a simple configuration. In the configuration of the fifth embodiment, the configuration becomes simpler by using two impedances connected in series.

  In addition, it is possible to reduce the number of parts and reduce the cost by using the impedances Z51 and Z52 provided for detecting the unbalanced component of the transmission line as the termination impedance in the transmission line.

  FIG. 22 shows a first modification of the line state detection device according to the fifth embodiment. This first modification is a configuration in which one of the conductors W1 or W2 (W2 in the illustrated example) or the transmission unit 53 of the transmission line is connected to the detection unit 51 in the configuration of FIG. In this configuration, the detection unit 51 detects the voltage at the intersection of the impedances Z51 and Z52 and inputs a part of the transmission signal transmitted from the transmission unit 53 or a transmission signal transmitted through the conductor W1 or W2. The phase of the voltage of the unbalanced component in the conductors W1 and W2 is compared with the signal of the transmission signal or the conductor W1 or W2. Thereby, the direction of the unbalanced current can be detected along with the magnitude of the unbalanced component between the conductors W1 and W2. In addition, when the phase is compared in the detection part 51, you may use the phase of both voltages in the conductors W1 and W2.

  22, the detection unit 51 calculates the product of the voltage of the unbalanced component in the conductors W1 and W2 detected by the detection unit 51 and the voltage of the transmission signal extracted from the transmission unit 53. It is good. Accordingly, the amount of unbalanced component between the conductors W1 and W2 of the transmission line can be detected by the calculated value of the product, and the direction of the unbalanced current can be detected by the sign of the calculated value.

  FIG. 23 shows a second modification of the line state detection device according to the fifth embodiment. In the second modification, in the configuration of FIG. 21, a part of the transmission signal transmitted from the transmission unit 53 is input, and the phase of the voltage of the transmission signal is shifted and output to the detection unit 51. It is the structure provided with. The phase shift circuit P51 may be either one that performs an analog phase shift using a delay element or the like, or one that performs a digital phase shift process using a digital circuit. In this configuration, the phase shift circuit P51 performs phase compensation by advancing or delaying the phase of the transmission signal extracted from the transmission unit 53. The detector 51 detects the voltage between the intersection of the impedances Z51 and Z52 and the ground potential, and inputs the transmission signal phase-compensated by the phase shift circuit P51, and the unbalanced component voltage and the transmission signal in the conductors W1 and W2. The product with the voltage of is calculated. Thereby, it is possible to accurately detect the value of the unbalanced component and the direction of the unbalanced current between the conductors W1 and W2 of the transmission line.

  FIG. 24 shows a third modification of the line state detection device according to the fifth embodiment. This third modification is a configuration provided with a phase shift circuit P52 that shifts the phase of the unbalanced voltage of the transmission line due to the intersection voltage of the impedances Z51 and Z52 and outputs the phase to the detection unit 51 in the configuration of FIG. The phase shift circuit P52 may be either one that performs an analog phase shift using a delay element or the like, or one that performs a digital phase shift process using a digital circuit. In this configuration, the phase shift circuit P52 performs phase compensation by advancing or delaying the phase of the voltage at the intersection of the impedances Z51 and Z52. The detection unit 51 inputs the voltage between the intersection of the impedances Z51 and Z52 phase-compensated by the phase shift circuit P52 and the ground potential, and a part of the transmission signal transmitted from the transmission unit 53, and calculates the product of these. To do. Thereby, it is possible to accurately detect the value of the unbalanced component and the direction of the unbalanced current between the conductors W1 and W2 of the transmission line.

  According to the line state detection device of the fifth embodiment, the conductors W1 and W2 are provided on the transmission line side of the transmission transformer T51 inserted between the transmission line including the conductors W1 and W2 and the transmission unit 53. By detecting the potential at the intersection of the two impedances Z51 and Z52 connected in series between them with the detection unit 51, the difference in current or voltage between the conductors W1 and W2, that is, the unbalanced component is directly detected with a simple configuration. be able to.

  In addition, the detection unit 51 compares the phase of the voltage of the unbalanced component detected in the above configuration with the voltage of the transmission signal extracted from the transmission unit 53, or calculates the product of the two, thereby calculating the conductor of the transmission line. The direction of the unbalanced current can be detected along with the value of the unbalanced component between W1 and W2. Further, the phase of the voltage of the transmission signal taken out from the transmission unit 53 or the phase of the midpoint voltage of the conductors W1 and W2 is compensated by the phase shift circuit, and the product of the midpoint voltage of these conductors W1 and W2 and the transmission signal is compensated. By calculating the direction and absolute amount of the unbalanced component in the transmission line.

(Sixth embodiment)
FIG. 25 is a diagram showing a basic configuration of a line state detection device according to the sixth embodiment of the present invention. In the sixth embodiment, in addition to the configuration of the fifth embodiment, an unbalanced component is detected via a transformer. The line state detection device according to the present embodiment includes a transmission transformer T61 inserted between the transmission line and the transmission unit 63 in a transmission line including a pair of conductors W1 and W2 connected to the transmission unit 63, and a transmission. Two impedances Z61 and Z62 connected in series between the conductors W1 and W2 on the transmission line side of the transformer T61, and a detection transformer T62 in which a primary winding is connected between the intersection of the impedances Z61 and Z62 and the ground, and detection And a detector 61 that detects the current or voltage of the secondary winding of the transformer T62.

  In this configuration, the detection unit 61 detects the voltage at the intersection of the impedances Z61 and Z62, that is, the midpoint voltage of the conductors W1 and W2 of the transmission line, thereby detecting the common mode voltage (unbalanced) in the conductors W1 and W2 of the transmission line. Voltage) can be detected directly. Therefore, it is possible to detect the unbalanced component of the transmission power from the transmitter 63 in a state separated from the transmission line. In the configuration of the sixth embodiment, since the detection unit for detecting the unbalanced component is provided in a form separated from the transmission line, the influence of the detection unit on the transmission line can be eliminated, and the transmission line is more accurately detected. It is possible to detect an unbalanced component in.

  FIG. 26 shows a first modification of the line state detection device according to the sixth embodiment. The first modification is a configuration in which the transmission unit 63 is connected to the detection unit 61 in the configuration of FIG. In this configuration, the detection unit 61 detects the voltage at the intersection of the impedances Z61 and Z62, and inputs a part of the transmission signal transmitted from the transmission unit 63, and this transmission signal and the unbalanced components in the conductors W1 and W2 Compare the phase of the current and / or voltage. Thus, the magnitude of the unbalanced component between the conductors W1 and W2 and the direction of the unbalanced current can be detected in a state separated from the transmission line.

  26, the product of the current or voltage of the unbalanced component in the conductors W1 and W2 detected by the detection unit 61 and the current or voltage of the transmission signal extracted from the transmission unit 63 is detected by the detection unit 61. It is good also as a structure calculated in. Accordingly, the amount of unbalanced component between the conductors W1 and W2 of the transmission line can be detected by the calculated value of the product, and the direction of the unbalanced current can be detected by the sign of the calculated value.

  FIG. 27 shows a second modification of the line state detection device according to the sixth embodiment. In the second modification, in the configuration of FIG. 25, a part of the transmission signal transmitted from the transmission unit 63 is input, and the phase of the current or voltage of the transmission signal is shifted and output to the detection unit 61. The circuit P61 is provided. The phase shift circuit P61 may be either one that performs an analog phase shift using a delay element or the like, or one that performs a digital phase shift process using a digital circuit. In this configuration, the phase shift circuit P61 performs phase compensation by advancing or delaying the phase of the transmission signal extracted from the transmission unit 63. The detector 61 detects the voltage at the intersection of the impedances Z61 and Z62, and inputs the transmission signal phase-compensated by the phase shift circuit P61, and the current or voltage of the unbalanced component and the current of the transmission signal in the conductors W1 and W2. Alternatively, the product with the voltage is calculated. As a result, the value of the unbalanced component and the direction of the unbalanced current between the conductors W1 and W2 of the transmission line can be accurately detected in a state where it is separated from the transmission line.

  FIG. 28 shows a third modification of the line state detection device according to the sixth embodiment. This third modification is a configuration provided with a phase shift circuit P62 that shifts the phase of the unbalanced voltage of the transmission line due to the intersection voltage of the impedances Z61 and Z62 and outputs the phase to the detection unit 61 in the configuration of FIG. The phase shift circuit P62 may be either one that performs an analog phase shift using a delay element or the like, or one that performs a digital phase shift process using a digital circuit. In this configuration, the phase shift circuit P62 performs phase compensation by advancing or delaying the phase of the voltage at the intersection of the impedances Z61 and Z62. The detection unit 61 inputs the voltage between the intersection of the impedances Z61 and Z62 phase-compensated by the phase shift circuit P62 and the ground potential, and a part of the transmission signal transmitted from the transmission unit 63, and calculates the product of these. To do. As a result, the value of the unbalanced component and the direction of the unbalanced current between the conductors W1 and W2 of the transmission line can be accurately detected in a state where it is separated from the transmission line.

  According to the line state detection device of the sixth embodiment, the conductors W1 and W2 are provided on the transmission line side of the transmission transformer T61 inserted between the transmission line composed of the conductors W1 and W2 and the transmission unit 63. By detecting the potential at the intersection of the two impedances Z61 and Z62 connected in series between them with the detection unit 61, the difference in current or voltage between the conductors W1 and W2, that is, the unbalanced component is separated from the transmission line. Can be detected.

  In addition, the detection unit 61 compares the phase of the voltage of the unbalanced component detected in the above configuration with the voltage of the transmission signal extracted from the transmission unit 63, or calculates the product of the two, thereby calculating the conductor of the transmission line. The direction of the unbalanced current can be detected along with the value of the unbalanced component between W1 and W2. Further, the phase of the voltage of the transmission signal taken out from the transmission unit 63 or the phase of the midpoint voltage of the conductors W1 and W2 is compensated by the phase shift circuit, and the product of the midpoint voltage of these conductors W1 and W2 and the transmission signal is compensated. By calculating the direction and absolute amount of the unbalanced component in the transmission line.

(Seventh embodiment)
FIG. 29 is a diagram showing a basic configuration of a line state detection device according to the seventh embodiment of the present invention. The line state detection apparatus of the present embodiment includes a transmission transformer T71 inserted between the transmission line and the transmission unit 73 in a transmission line composed of a pair of conductors W1 and W2 connected to the transmission unit 73, and transmission. Two coils L71 and L72 connected in series between the conductors W1 and W2 on the transmission line side of the transformer T71, and a detector 71 for detecting the voltage between the connection between the coils L71 and L72 and the ground potential It is comprised.

  In this configuration, the detection unit 71 detects the voltage at the intersection of the coils L71 and L72, that is, the midpoint voltage of the transmission line conductors W1 and W2, thereby detecting the common mode voltage (unbalanced) in the transmission line conductors W1 and W2. Voltage) can be detected directly. Therefore, it is possible to detect the unbalanced component of the transmission power from the transmission unit 73 with a simple configuration. In the configuration of the seventh embodiment, the configuration is further simplified by using two coils connected in series.

  As a first modification, a detection transformer having a primary winding connected between the intersection of the coils L71 and L72 and the ground is provided, and the current or voltage of the secondary winding of the detection transformer is detected by the detection unit 71. It is good also as composition to do. Thereby, an unbalanced component can be detected in a state separated from the transmission line.

  As a second modification, a part of the transmission signal transmitted from the transmission unit 73 and a transmission signal transmitted through the conductor W1 or W2 are input to the detection unit 71, and the transmission signal and the non-transmission in the conductors W1 and W2 are input. The phase of the voltage of the equilibrium component may be compared by the detection unit 71. Thereby, the direction of the unbalanced current can be detected along with the magnitude of the unbalanced component between the conductors W1 and W2. In addition, when comparing the phase in the detection part 71, you may use the phase of any one or both of the voltage in the conductors W1 and W2.

  As a third modification, the detector 71 may calculate the product of the voltage of the unbalanced component in the conductors W1 and W2 detected by the detector 71 and the voltage of the transmission signal extracted from the transmitter 73. . Accordingly, the amount of unbalanced component between the conductors W1 and W2 of the transmission line can be detected by the calculated value of the product, and the direction of the unbalanced current can be detected by the sign of the calculated value.

  According to the line state detection apparatus of the seventh embodiment, the conductors W1 and W2 are provided on the transmission line side of the transmission transformer T71 inserted between the transmission line including the conductors W1 and W2 and the transmission unit 73. By detecting the potential of the intersection of the two coils L71 and L72 connected in series between them with the detection unit 71, it is possible to detect a difference in current or voltage between the conductors W1 and W2, that is, an unbalanced component with a simple configuration. Can do.

(Eighth embodiment)
FIG. 30 is a diagram showing a basic configuration of a line state detection device according to the eighth embodiment of the present invention. The line state detection device according to the present embodiment includes a transmission transformer T81 inserted between the transmission line and the transmission unit 83 in a transmission line including a pair of conductors W1 and W2 connected to the transmission unit 83, and a transmission. Coil L81 having a midpoint tap connected between conductors W1 and W2 on the transmission line side of transformer T81, and a detector 81 for detecting the voltage between the midpoint of coil L81 and the ground potential. The

  In this configuration, the detection unit 81 detects the voltage at the midpoint of the coil L81, that is, the midpoint voltage of the transmission line conductors W1 and W2, thereby detecting the common mode voltage (unbalanced voltage) at the transmission line conductors W1 and W2. ) Can be detected directly. Therefore, it is possible to detect the unbalanced component of the transmission power from the transmission unit 83 with a simple configuration. In the configuration of the eighth embodiment, the configuration becomes simpler by using a coil having a midpoint tap.

  As a first modification, a detection transformer in which a primary winding is connected between the middle point of the coil L81 and the ground is provided, and the current or voltage of the secondary winding of the detection transformer is detected by the detection unit 81. It is good also as a structure. Thereby, an unbalanced component can be detected in a state separated from the transmission line.

  As a second modification, a part of the transmission signal transmitted from the transmission unit 83 or a transmission signal transmitted to the conductor W1 or W2 is input to the detection unit 81, and the transmission signal and the non-transmission in the conductors W1 and W2 are input. The phase of the voltage of the equilibrium component may be compared by the detection unit 81. Thereby, the direction of the unbalanced current can be detected along with the magnitude of the unbalanced component between the conductors W1 and W2. In addition, when comparing the phase in the detection part 81, you may use the phase of any one or both of the voltage in the conductors W1 and W2.

  As a third modification, the detection unit 81 may calculate the product of the voltage of the unbalanced component in the conductors W1 and W2 detected by the detection unit 81 and the voltage of the transmission signal extracted from the transmission unit 83. . Accordingly, the amount of unbalanced component between the conductors W1 and W2 of the transmission line can be detected by the calculated value of the product, and the direction of the unbalanced current can be detected by the sign of the calculated value.

  According to the line state detection apparatus of the eighth embodiment, the conductors W1 and W2 are provided on the transmission line side of the transmission transformer T81 inserted between the transmission line including the conductors W1 and W2 and the transmission unit 83. By detecting the potential of the middle point of the coil L81 connected between the detectors 81, the difference in current or voltage between the conductors W1 and W2, that is, the unbalanced component can be detected with a simple configuration.

  In the first to eighth embodiments, the transmission signal transmitted from the transmission unit may be used to detect the unbalanced component between the conductors W1 and W2 in consideration of the output timing of the transmission signal. Good. For example, when the transmission signal is not output, the operation of the detection unit and the difference circuit is stopped, or the output of the difference circuit is turned off to detect the unbalanced component between the conductors W1 and W2 during non-transmission. Output can be excluded.

  Further, in the first to eighth embodiments, each configuration element has been described as a configuration example expressed by an electronic element such as a circuit block or a transformer. However, the above configuration example is applicable as long as it has a similar function or function. However, the present invention is not limited to this, and can be realized by various configurations such as an analog circuit, a digital circuit, and a combination of electronic elements. In addition, the function of each component may be realized by hardware processing, software processing, or the like. It is also possible to reduce the size of the device by integrating part or all of the circuit.

  In addition, when performing corrections such as phase compensation when detecting unbalanced components, and control of transmission line balance based on the detected unbalanced components, the amount of deviation from the correction target value is corrected as a correction amount. Alternatively, on the contrary, a configuration in which the difference between the correction target value and the deviation amount is corrected as the correction amount may be employed.

  As described above, according to the present embodiment, the balanced state of the transmission line in the balanced transmission system can be detected, and based on the detection result, the level of the transmission signal sent to the transmission line is adjusted, for example, to balance the transmission line. The state can be controlled and the balance can be improved. Thereby, leakage power from the transmission line to the outside can be reduced, and deterioration of data transmission characteristics and interference with others can be suppressed. For example, when applied to a balanced transmission system such as a power line communication system using a power line as a transmission line, a more remarkable effect can be obtained.

  The present invention has an effect that it is possible to detect a balanced state of a transmission line in a balanced transmission system that performs data transmission using a pair of conductors. It can be controlled based on the detection result, and has the effect of improving the balance, and is useful for a line state detection device in a balanced transmission system, and a transmission device and a reception device of a balanced transmission system including the same. It is.

The figure which shows schematic structure of the transmitter of the balanced transmission apparatus which concerns on embodiment of this invention. The figure which shows schematic structure of the receiver of the balanced transmission apparatus which concerns on embodiment of this invention. The figure which shows schematic structure of the balanced transmission system provided with the transmitter and receiver which concern on embodiment of this invention. The figure which shows the basic composition of the track | line state detection apparatus which concerns on the 1st Embodiment of this invention. The figure which shows the 1st modification of the track | line state detection apparatus which concerns on 1st Embodiment. The figure which shows the 2nd modification of the track | line state detection apparatus which concerns on 1st Embodiment. The figure which shows the 3rd modification of the track | line state detection apparatus which concerns on 1st Embodiment. The figure which shows the basic composition of the track | line state detection apparatus which concerns on the 2nd Embodiment of this invention. The figure which shows the structural example which provided the common mode coil which concerns on 2nd Embodiment in the inlet connector for the power cord connection of the apparatus in the power line communication system which used the power line for the transmission line The figure which shows the 1st modification of the track | line state detection apparatus which concerns on 2nd Embodiment. The figure which shows the 2nd modification of the track | line state detection apparatus which concerns on 2nd Embodiment. The figure which shows the 3rd modification of the track | line state detection apparatus which concerns on 2nd Embodiment. The figure which shows the basic composition of the track | line state detection apparatus which concerns on the 3rd Embodiment of this invention. The figure which shows the 1st modification of the track | line state detection apparatus which concerns on 3rd Embodiment. The figure which shows the 2nd modification of the track | line state detection apparatus which concerns on 3rd Embodiment. The figure which shows the 3rd modification of the track | line state detection apparatus which concerns on 3rd Embodiment. The figure which shows the basic composition of the track | line state detection apparatus which concerns on the 4th Embodiment of this invention. The figure which shows the 1st modification of the track | line state detection apparatus which concerns on 4th Embodiment. The figure which shows the 2nd modification of the track | line state detection apparatus which concerns on 4th Embodiment. The figure which shows the 3rd modification of the track | line state detection apparatus which concerns on 4th Embodiment. The figure which shows the basic composition of the track | line state detection apparatus which concerns on the 5th Embodiment of this invention. The figure which shows the 1st modification of the track | line state detection apparatus which concerns on 5th Embodiment. The figure which shows the 2nd modification of the track | line state detection apparatus which concerns on 5th Embodiment. The figure which shows the 3rd modification of the track | line state detection apparatus which concerns on 5th Embodiment. The figure which shows the basic composition of the track | line state detection apparatus which concerns on the 6th Embodiment of this invention. The figure which shows the 1st modification of the track | line state detection apparatus which concerns on 6th Embodiment. The figure which shows the 2nd modification of the track | line condition detection apparatus which concerns on 6th Embodiment. The figure which shows the 3rd modification of the track | line state detection apparatus which concerns on 6th Embodiment. The figure which shows the basic composition of the track | line state detection apparatus which concerns on the 7th Embodiment of this invention. The figure which shows the basic composition of the track | line state detection apparatus which concerns on the 8th Embodiment of this invention. The figure which shows an example of the transmission part and transmission line of the conventional balanced transmission apparatus

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transmitter 2, 5 Line state detection apparatus 3, 13, 23, 33, 43, 53, 63, 73, 83 Transmitter 4 Receiver 6 Receiver 11, 21, 31, 41, 51, 61, 71, 81 Detector L21 Common mode coil L71, L72, L81 Coil T11, T12 Current transformer T31, T41, T51, T61, T71, T81 Transmission transformer T42, T62 Detection transformer W1, W2 Conductors Z31, Z51, Z52, Z61, Z62 Impedance P11, P12, P21, P22, P31, P32, P41, P42, P51, P52, P61, P62 Phase shift circuit

Claims (20)

A line state detection device for detecting a state of a transmission line in a balanced transmission system that performs data transmission using a pair of conductors,
A line state detecting device comprising unbalanced component detecting means for directly detecting an unbalanced component between the pair of conductors. The line state detection device according to claim 1,
The pair of conductors is a line state detection device which is a power line. The line state detection device according to claim 1 or 2,
The unbalanced component detection means includes a current transformer in which a primary winding is inserted in series in each of the pair of conductors and the secondary windings are connected in series, and the secondary winding connected in series. A detection unit for detecting current or voltage,
The secondary winding of the current transformer is a line state detection device connected so as to cancel the currents or voltages in both transformers. The line state detection device according to claim 1 or 2,
The unbalanced component detecting means includes a common mode coil having a first winding and a second winding inserted in series in each of the pair of conductors, and a third winding for detecting a common mode, A line state detection device including a detection unit that detects a voltage or current induced in the third winding. A power supply comprising an unbalanced component detecting means for directly detecting an unbalanced component between the pair of conductors, used in a line state detecting device for detecting a state of a transmission line in a balanced transmission system for performing data transmission using a pair of conductors A connected device,
As the unbalanced component detecting means, a power supply including a common mode coil having a first winding and a second winding inserted in series in each of the pair of conductors and having a third winding for common mode detection Connected equipment. The line state detection device according to claim 1 or 2,
The unbalanced component detection unit is a line state detection device including an impedance provided between the pair of conductors and a detection unit that detects a current or voltage between a midpoint of the impedance and the ground. The line state detection device according to claim 6,
A line state detection device having a detection transformer in which a primary winding is inserted between the middle point of the impedance and the ground, and the detection unit detects a current or a voltage of a secondary winding of the detection transformer. The line state detection device according to claim 6,
The impedance is a line state detection device that also serves as a termination impedance of the transmission line. The line state detection device according to claim 1 or 2,
The transmission line is connected to a transmission device or a reception device via a transmission transformer,
The unbalanced component detection means is a line state detection device including an impedance connected to a midpoint of a transmission line side winding of the transmission transformer and a voltage detection unit for detecting a voltage between the impedance and the ground. The line state detection device according to claim 1 or 2,
The transmission line is connected to a transmission device or a reception device via a transmission transformer,
The unbalanced component detecting means is a line state detecting device including a detecting unit for detecting a current or voltage between a midpoint of a transmission line side winding of the transmission transformer and a ground. The line state detection device according to claim 9 or 10,
The detection transformer includes a detection transformer in which a primary winding is inserted between a midpoint of the transmission line side winding of the transmission transformer and the ground, and the detection unit outputs a current or a voltage of the secondary winding of the detection transformer. Line state detection device to detect. The line state detection device according to any one of claims 1 to 4 or claims 6 to 11,
The unbalanced component detecting means is a line state detecting device that calculates the magnitude and direction of the unbalanced component between the pair of conductors. The line state detection device according to claim 12,
The unbalanced component detection unit is a line state detection device that performs phase comparison between a transmission signal output to the conductor and a current or voltage of a difference between a forward path and a return path in the conductor. The line state detection device according to claim 12,
The unbalanced component detection means is a line state detection device that calculates a product of a transmission signal output to the conductor and a current or voltage of a difference between the forward path and the return path in the conductor. The line state detection device according to claim 12,
A line state detection device comprising phase shift means for adjusting a phase of at least one of a transmission signal output to the conductor and a difference current or voltage between a forward path and a return path in the conductor. A transmission device for use in a balanced transmission system that performs data transmission using a pair of conductors,
A transmission apparatus provided with the transmission side line state detection apparatus which consists of a line state detection apparatus as described in any one of Claims 1 thru | or 4 or claim 6 thru | or 15. The transmission device according to claim 16, comprising:
A transmission apparatus comprising a transmission signal control unit for controlling a transmission signal output to the conductor based on an output of the transmission-side line state detection apparatus. A receiving device used in a balanced transmission system that performs data transmission using a pair of conductors,
A reception-side line state detection device comprising the line state detection device according to any one of claims 1 to 4 or claims 6 to 15,
A receiving apparatus comprising: a line state output unit that outputs a state detection signal indicating a line state of the transmission line based on an output of the receiving side line state detecting apparatus. A transmission device for use in a balanced transmission system that performs data transmission using a pair of conductors,
A transmission apparatus comprising a transmission signal control unit that controls a transmission signal output to the conductor based on the state detection signal output from the reception apparatus according to claim 18. A balanced transmission system that performs data transmission using a pair of conductors,
A transmission-side line state detection device comprising the line state detection device according to any one of claims 1 to 4 or claim 6 to 15, and a transmission signal control unit that controls a transmission signal output to the conductor. A transmission device comprising:
A line condition of the transmission line based on an output of the reception-side line condition detection apparatus comprising the line condition detection apparatus according to any one of claims 1 to 4 or claims 6 to 15, and an output of the reception-side line condition detection apparatus. A line state output unit that outputs a state detection signal indicating a receiving device,
The transmission signal control unit is a balanced transmission system that controls a transmission signal output to the conductor based on an output of the transmission-side line state detection device and the state detection signal output from the reception device.

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