JP2016075600A - Current and phase measurement system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a current and phase measurement system that is easy to install while reducing the size and weight by a technique which does not take insulation into consideration.SOLUTION: Detection processing devices IR, IS, and IT each have reference time generation means 13, information processing means 12, and radio equipment 14, and are configured to send out a reference time signal for starting measuring current signals of different phase at the same time based upon time obtained by reference time generation means 13 so as to process a current and a current waveform. The information processing means 12 generates current signal data by processing the current and current waveform detected by a detection processing device installed for each power transmission line. The radio equipment 14 is configured to transmit the current signal data toward a ground-side data processing device, which is so configured to receive information sent over an arbitrary power distribution line from the data sent from the detection processing devices IR, IS, and IT so as to detect a current value of each power transmission line, a phase difference between phases, and waveform distortion.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a current / phase measurement system, and is particularly useful when applied to the case of detecting a phase between currents together with a current in a high-voltage transmission line.

  In a system aimed at examining ground faults, insulation defects, etc. of high-voltage power transmission lines, it is necessary to measure the current flowing through the power transmission lines. When measuring a current flowing through a transmission line, conventionally, a current transformer is attached to the transmission line to be measured, and a current signal detected by the current transformer is measured by a measurement unit on the ground. For this type of current transformer, for example, a split-type current transformer as disclosed in Patent Document 1 is used. In this case, a predetermined current signal is transmitted from the current transformer attached to the power transmission line to the measurement unit via the measurement cable.

  Further, Patent Document 2 exists as a current measurement device that measures a current flowing through a transmission line including a phase difference between phases. However, in the case of Patent Document 2, a predetermined current signal is transmitted from a coil mounted on a power transmission line and wound around a magnetic core serving as a current measurement unit to a measurement unit on the ground via a measurement cable. Yes. Thus, the phase between each phase is detected together with the current flowing through each phase of the transmission line. That is, the desired measurement information in this case is obtained by processing the current signal transmitted from the power transmission line via the measurement cable on the ground.

JP 2002-71727 A Japanese Patent Laid-Open No. 5-312846

  In the prior art as described above, a current signal detected by a current sensor such as a current transformer attached to a power transmission line is transmitted to a measurement unit on the ground via a measurement cable. For this reason, it is necessary to route a long measurement cable from a high-level transmission line to a measurement unit on the ground. Here, assuming the case where the voltage of the transmission line to be measured is 10 kV or higher, the above-described current transformer and measurement cable require high insulation performance. For this reason, the large current transformer which considered the insulation resistance and creepage distance, and the measurement cable considered similarly are required. As a result, since the size and weight of the measurement cable increase, a large-scale construction for installation is required, and it is not possible to perform measurement by simple manual installation. In short, by using cables, it is necessary to consider the insulation corresponding to the voltage of the transmission line to be measured. However, when high insulation is taken into account, the measurement cables, etc. are large and the weight is increased. I can't.

  In view of the above prior art, the present invention is a method that does not consider insulation even when measuring current and current phase waveform in a high-voltage power transmission line, and is easy to install after reducing size and weight. An object is to provide a current / phase measurement system.

The first aspect of the present invention for achieving the above object is as follows:
A current detection sensor that detects current and current waveform flowing in an arbitrary transmission line that transmits alternating current at the installation point, and a function for processing the current and current waveform. A current / phase measurement system comprising: a detection processing device having a function of wirelessly transmitting information on the current and current waveform to a data processing device; and power supply means for supplying driving power to the detection processing device,
The detection processing apparatus includes a reference time generation unit, an information processing unit, and a wireless transmission unit,
Further, the reference time generating means is a reference time signal representing a reference time for aligning the measurement start times of the current signals of the different phases with reference to the time obtained by the time measuring means for processing the current and the current waveform. Configured to send
The information processing means is configured to generate current signal data by processing current and current waveform detected by a detection processing device installed in each power transmission line,
The wireless transmission means is configured to wirelessly transmit the current signal data to the ground side data processing device,
The ground side data processing device receives information flowing in an arbitrary power transmission line from the data transmitted from the detection processing device, and based on the current and current waveform of each power transmission line and the time obtained by the reference time generating means. The current / phase measurement system is configured to detect a current value, a phase difference between phases, and a distortion of a waveform.

  According to this aspect, the predetermined current signal data can be transmitted without routing the measurement cable from the power transmission line side, so that desired current measurement can be performed safely and quickly. Here, the phases of the phases R, S, and T are aligned with the reference time signal, and the measurement period is specified using a predetermined reference point, so that the phase difference between the desired phases can be accurately detected. Can do.

The second aspect of the present invention is:
In the current / phase measurement system according to the first aspect,
The detection processing device is characterized in that reference time generating means, information processing means, and wireless transmission means are housed in a casing and are integrally disposed on the power transmission line together with the current detection sensor and power supply means. In the current / phase measurement system.

  According to this aspect, since the devices are collectively required for the measurement in the housing, it can be made compact and excellent in handleability as a whole.

The third aspect of the present invention is:
In the current / phase measurement system according to the first or second aspect,
In the current / phase measurement system, the reference time signal is a time data signal in GPS.

  According to this aspect, since the existing GPS is used, the system configuration can be rationalized.

The fourth aspect of the present invention is:
In the current / phase measurement system according to any one of the first to third aspects,
In the current / phase measurement system, the power supply means is a current transformer attached to the power transmission line.

  According to this aspect, since a desired voltage can be generated using the current flowing through the current transformer, the necessary power can be easily obtained.

  According to the present invention, since current signal data including phase information can be transmitted wirelessly without routing a measurement cable from the power transmission line side, desired current measurement can be performed safely and quickly. Here, the phase of each phase of the transmission line at the time of current measurement is aligned with the reference time signal and the measurement period is specified using a predetermined reference point, so the phase difference between each phase is also accurately detected can do.

It is explanatory drawing shown notionally in the state which mounted | wore the power transmission line with the electric current and phase measurement system which concerns on embodiment of this invention. 1 is a block diagram showing a current / phase measurement system according to an embodiment of the present invention. It is a block diagram which extracts and shows the detection processing apparatus of the electric current and phase measurement system which concerns on embodiment of this invention in detail. It is a wave form diagram which shows the concept of the predetermined period which takes in a measurement start point and a current signal with the waveform of the current signal of each phase. It is a wave form diagram which shows a waveform at the time of synthesize | combining the electric current signal of each phase shown in FIG. 4 on the ground side.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same number is attached to the same part, and duplicate explanation is omitted.

  FIG. 1 is an explanatory diagram conceptually showing a current / phase measurement system according to an embodiment of the present invention mounted on a transmission line, and FIG. 2 is a block diagram showing the current / phase measurement system according to this embodiment. As shown in both figures, each of the phases R, S, T of the three transmission lines 1 suspended from the tower 100 so as to transmit three-phase AC power has a current transformer 2R, which is a current detection sensor. 2S, 2T, current transformers 3R, 3S, 3T constituting power supply means and a casing 18 in which detection processing devices IR, IS, IT are housed are fixed integrally. From the detection processing devices IR, IS, IT of the respective phases R, S, T, current signal data subjected to predetermined processing is transmitted as radio waves 15 toward the receiving means IV on the ground 17.

  In the case of the present embodiment, the receiving means IV on the ground 17 side is a terminal that processes the current signal data received by the receiving units IIR, IIS, IIT corresponding to the phases R, S, T and the receiving units IIR, IIS, IIT. And III. The terminal III detects the phase difference between the phases based on the currents of the phases R, S, and T and the currents based on the current signal data of the phases R, S, and T.

  FIG. 3 is a block diagram showing details of the detection processing device of the current / phase measurement system according to the present embodiment. As shown in the figure, current transformers 2R, 2S, and 2T, which are current detection sensors, are directly fixed to the transmission line 1, and the current flowing through the transmission line 1 (see FIG. 1 or 2; the same applies hereinafter) flows. Detect each. The detection processing devices IR, IS, and IT include a filter / amplifier / AD conversion unit 11, an information processing unit 12, a reference time generation unit 13, and a wireless device 14. Here, the filter / amplifier / AD converter 11 inputs a current signal representing the current flowing through the transmission line 1 detected by the current transformers 2R, 2S, 2T, removes noise by the filter, and performs predetermined amplification. Is performed and then converted into a digital signal. Therefore, a current signal converted into a digital signal is input to the information processing means 12 and stored as a digital signal in the data storage 12A. In the CPU 12B, a predetermined process for aligning the measurement start time points in the current signals of the phases R, S, T supplied from the data storage 12A based on the reference time signal supplied from the reference time generating means 13 (to be described in detail later). And current signal data of a predetermined period is processed with reference to the reference time to generate current signal data. Further, the CPU 12B in the present embodiment calibrates the delay of the signal from the current transformers 2R, 2S, 2T to the CPU 12B based on the calibration signal SC supplied via the interface IF. As a result, the measurement start point based on the reference time can be made more accurate, and the current signal data generated based on the reference time can be made more accurate.

  The reference time generating means 13 in this embodiment is composed of GPS. Therefore, the reference time signal is a time data signal in GPS. However, the reference time generating means 13 and the reference time signal need not be limited to this. There is no further limitation as long as it has the same function and gives an absolute time reference. Other radio clocks can be applied. The wireless device 14 constituting the wireless transmission means transmits a radio wave 15 so as to wirelessly transmit the current signal data generated by the CPU 12B to the reception means IV (see FIG. 2) on the ground side. In this case, the specific low power radio can be suitably applied to the radio transmission.

  Each device as described above of the detection processing devices IR, IS, and IT is driven by using a voltage generated by the power supply circuit 16. The power supply circuit 16 supplies the current flowing through the power transmission line 1 taken in by the current transformers 3R, 3S, and 3T disposed in the power transmission line 1 to, for example, the load resistance of the power supply circuit 16, thereby reducing the load resistance. A predetermined drive voltage is generated at both ends.

  The generation of the current signal data in the CPU 12 is performed with reference to the reference time signal. The manner of generating such current signal data will be described in detail with reference to FIG. FIG. 4 is a waveform diagram showing the concept of a measurement start point and a predetermined period for capturing a current signal, along with the waveforms of the current signals of the phases R, S, and T. (a) is the R phase, and (b) is the S phase. Phase (c) shows a T-phase current signal. Each phase R.D. S. The delay of the signal from the current transformers 2R, 2S, 2T to the CPU 12B is already calibrated in the CPU 12 based on the calibration signal SC supplied through the interface IF.

  In this state, a common start point SP (black triangle point in the figure) for each phase R, S, T is determined based on a reference time signal that is an output signal of GPS. Next, the first reference points SR, SS, ST are detected on the time axis of each phase R, S, T after the start point SP for each phase R, S, T. As a result, for the R phase, the current value is detected at the level of the current signal after the start point SP, and the first reference point SR becomes the reference phase. For the S phase, the current value is detected at the level of the current signal from the start point SP, and the phase difference between the first reference point SS and the reference point SR becomes the phase difference between the R phase and the S phase. For the T phase, the current value is detected at the level of the current signal from the start point SP, and the phase difference between the first reference point ST and the reference point SR becomes the phase difference between the R phase and the T phase. Here, the current signal data in this embodiment is generated based on current signals of three periods after the reference points SR, SS, ST. The current signal data includes not only current value data based on the current signals of the phases R, S, and T but also accurate phase information obtained from the result of a predetermined calculation in the CPU 12.

  FIG. 5 is a waveform diagram when the current signals of the respective phases shown in FIGS. 4A to 4C are combined on the ground side. As shown in the figure, the phases of the S phase and the T phase with respect to the R phase can be detected at intervals of white triangles in the figure. By utilizing this relationship, the phase between the S phase and the T phase can also be detected. In this embodiment, the terminal III of the receiving means IV on the ground 17 side calculates a predetermined phase difference between the phases R, S, and T based on the phase information transmitted by radio transmission from the power transmission line 1 side.

  Thus, according to the present embodiment, current signal data including phase information can be transmitted wirelessly without routing the measurement cable from the transmission line 1 side, so that desired current measurement can be performed safely and quickly. . Here, the phases of the phases R, S, and T are aligned with the reference time signal, and the measurement period is specified using a predetermined reference point. Therefore, the phases (R, S), (S, T ) And (T, R) can also be detected accurately.

  The phase difference is obtained for all the phases (R, S), (S, T), (T, R). However, if necessary, the phase differences (R, S), (S, T ), (T, R). For example, when a ground fault or the like occurs, the phase difference may be detected for a specific two phase. The current may be detected for at least one of the R, S, and T phases.

  Although the current sensor is formed of a current transformer in the above embodiment, it is not necessarily limited to this. Further, the power supply means need not be limited to the current transformer. In addition, as a power source means, a power source by an electromagnetic induction system, an environmental magnetic field power generation system, or a solar energy system can be considered.

  INDUSTRIAL APPLICABILITY The present invention can be effectively used in the electric power industry that performs high-voltage power transmission and the industrial field that performs maintenance and inspection of this type of high-voltage power transmission line.

IR, IS, IT detection processor
IIR, IIS, IIT receiver
III terminal
IV receiving means 1 power transmission line 2R, 2S, 2T current transformer 3R, 3S, 3T current transformer 12 information processing means 13 reference time generating means 14 radio equipment 15 radio wave 16 power supply circuit
17 Above ground 18 Case 100 Steel tower R, S, T phase

Claims (4)

A current detection sensor that detects current and current waveform flowing in an arbitrary transmission line that transmits alternating current at the installation point, and a function for processing the current and current waveform. A current / phase measurement system comprising: a detection processing device having a function of wirelessly transmitting information on the current and current waveform to a data processing device; and power supply means for supplying driving power to the detection processing device,
The detection processing apparatus includes a reference time generation unit, an information processing unit, and a wireless transmission unit,
Further, the reference time generating means is a reference time signal representing a reference time for aligning the measurement start times of the current signals of the different phases with reference to the time obtained by the time measuring means for processing the current and the current waveform. Configured to send
The information processing means is configured to generate current signal data by processing a current and a current waveform detected by a detection processing device installed in each power transmission line,
The wireless transmission means is configured to wirelessly transmit the current signal data to the ground side data processing device,
The ground side data processing device receives information flowing in an arbitrary power transmission line from the data transmitted from the detection processing device, and based on the current and current waveform of each power transmission line and the time obtained by the reference time generating means. And a current / phase measurement system configured to detect a current value, a phase difference between phases, and a waveform distortion. In the current / phase measurement system according to claim 1,
The detection processing device is characterized in that reference time generating means, information processing means, and wireless transmission means are housed in a casing and are integrally disposed on the power transmission line together with the current detection sensor and power supply means. Current / phase measurement system. In the current / phase measurement system according to claim 1 or 2,
The current / phase measurement system, wherein the reference time signal is a time data signal in GPS. In the current / phase measurement system according to any one of claims 1 to 3,
The current / phase measurement system, wherein the power supply means is a current transformer attached to the power transmission line.

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