JP3184024B2 - Harmonic source search display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for searching and displaying a harmonic source, which displays the direction of a harmonic source and the amount of harmonic power in a dendritic distribution line.

[0002]

2. Description of the Related Art In recent years, due to rapid technological innovation of power electronics and the like, semiconductor-applied devices ranging from industrial devices to home appliances and OA devices have become widespread. But,
These devices act as harmonic sources and the harmonics are superimposed on the distribution line. When many of these devices are connected to a distribution line, harmonics in the distribution line increase. As a result, harmonics are a serious problem, for example, a failure appears in a power factor improving capacitor or the like of a high-voltage facility having a small withstand harmonic.

Therefore, in order to identify the harmonic generation source, harmonic measurements are sequentially performed from the power supply side of the distribution line, and the dendritic line is carefully measured while determining the direction in which the harmonic current flows. Needed. Specifically, a sensor unit including a voltage transformer (PT) and a current transformer (CT) is arranged on a distribution line, and a phase current in each phase of the distribution line is detected by the sensor unit. Analyzes the harmonics,
The direction in which each harmonic power flows is output and displayed on a CRT screen, a liquid crystal screen, a print, or the like based on each harmonic wave voltage current phase difference. For example, the direction of the harmonic generation source is indicated by “+” on the power supply side and “−” on the load side, and the harmonic power is indicated by a numerical value.

[0004]

However, in this conventional harmonic measurement, since the exploration is performed by a single measuring device, a line branching at a complicated place such as a dendritic distribution line cannot be used. In addition, since the generation of harmonics of each order may vary greatly depending on the time zone, it is particularly difficult to determine the direction of the generation source.

The present invention has been made in view of such problems existing in the prior art. It is an object of the present invention to reduce the time required for discriminating the source of harmonics without increasing the tree length. It is an object of the present invention to provide a harmonic generation source search and display device capable of easily determining the generation direction at a branch point of a distribution line.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, an invention according to claim 1 is a detector for detecting a phase voltage and a phase current of a distribution line, and wirelessly transmitting a detection signal of the detector. A measuring unit comprising a transmitting unit, a receiving unit for receiving the detection signal, a calculating unit for calculating harmonic power for each harmonic order based on the received signal from the receiving unit, and a direction of a harmonic generation source. A direction discriminating means for discriminating, and an observation unit having a display means for displaying the harmonic power and the direction of the harmonic generation source calculated by the calculation means and the direction discriminating means, and the measuring unit is dendritic. Installed on each distribution line that constitutes a branch point of the distribution line, and each measurement unit is installed
The gist of the present invention is to display the direction of the harmonic generation source and the magnitude of the harmonic power for each order at the designated point on an arrow-shaped display unit.

Further, the invention according to claim 2 is characterized in that the display section displayed by the display means is displayed in a pattern or color that can be identified according to the harmonic order.

[0008]

According to the present invention constructed as described above, the detectors installed on each distribution line at the branch point of the distribution line are simultaneously operated to detect the phase voltage and the phase current of each distribution line. The direction determining means determines the direction of the harmonic generation source based on the detection signal. The calculating means calculates the harmonic power based on the detection signal. The display device has an arrow by a display means.
Display sign shape direction and the harmonic power of the harmonic source
The size is displayed for each order, and is displayed in an identifiable pattern or color for each order.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 2, the harmonic generation source exploration display device includes a plurality of measuring units 2, 3, 3 provided on a power distribution line 1 on a power supply side and a branch side at a branch point of a dendritic distribution line.
4 and an observation unit 5 installed on the ground. First, the measuring unit 2 will be described. Note that the other measuring units 3 and 4 have the same configuration as the measuring unit 2, and thus the description thereof is omitted.

As shown in FIG. 3, U, V,
A clamp-type detection body 6 is attached to the W phase. The detection body 6 includes an optical magnetic field sensor and an optical voltage sensor,
The voltage value and the current value of each phase can be detected. An O / E converter 7 common to each phase voltage and each phase current is connected to the detector 6 via an optical cable 6a. O /
A first signal control unit 10 is connected to the E converter 7 via an amplification filter 8 and an A / D converter 9. The first signal control unit 10 is common to each phase voltage and each phase current.
The first signal control unit 10 includes a first wireless device 1 as a transmitting unit.
1 is connected, and the detection signal can be transmitted to the observation unit 5 by the first wireless device 11.

Next, the observation section 5 will be described. As shown in FIG. 4, the observation unit 5 is provided with a second wireless device 12 as a receiving unit, and the second wireless device 12 controls each of the measurement units 2 to 2.
4 detection data can be collected. A computer 14 as a calculating means and a direction discriminating means is connected to the second wireless device 12 via a second signal control unit 13. Then, the computer 14 analyzes the harmonic source direction for each order and the harmonic power for each order in the measuring units 2 to 4 based on the detection data from the second signal control unit 13.

A printer 15 is connected to the computer 14, and the printer 15 can output detection data of the harmonic power source direction and the harmonic power for each order. Further, an output device 16 is connected to the computer 14, and the output device 16 is provided with a CRT display 17 as display means.

As shown in FIG. 1, a CRT display 1
On the screen 7, the power supply side and branch side distribution line display sections 18 can be displayed and controlled by the computer 14. Further, the computer 14 displays on the distribution line display unit 18 the harmonics for each order in the measuring units 2 to 4 .
Analysis processing data of source power and harmonic power for each order
Measuring device display unit 19-21 to be displayed, system impedance 22, dimming stand or the load display portion 23 and 24 of the harmonic generation load device such as a personal computer has become possible display control.

[0014] The computer 14, the display unit of the shown to arrow shape the size of the harmonic power of the harmonic source direction and for each order of each order in the vicinity of the measuring device the display unit 19 to 21 25 Can be displayed. That is, the arrow of the display unit 25 indicates the direction of the harmonic generation source, and the length indicates the magnitude of the harmonic power. In FIG. 1, the solid line display 25 indicates the third harmonic, the two-dot chain line display 25 indicates the fifth harmonic, and the dotted line display 25 indicates the seventh harmonic.

The display section 25 is distinguished by different colors for each order. The tertiary display unit 25 is displayed in blue, the quintic display unit 25 is displayed in red, and the tertiary display unit 25 is displayed in green.

The output device 16 is provided with an operation switch (not shown). The measurement parameters can be set by operating the operation switches. That is, switching between high pressure measurement or low pressure measurement, and current (500 A, 100 A, 50 A, and 10 A) during high pressure measurement
A) Switching, low-voltage measurement voltage (200 V and 100 V)
Switching of V) and switching of current (5 A and 1 A) at the time of low pressure measurement can be arbitrarily set. In addition, the display unit 25 of a desired order can be displayed by operating the operation switch.

In the measuring units 2 to 4 , the control power is secured by a battery (not shown).
5 and moving only the signal control circuitry which receives the operation signal from the high measuring operation of the battery consumption degree is adapted to operate only when it receives the operation signal from the observation unit 5, the power saving of the battery meter Have been.

Next, a description will be given of the measurement state of the harmonic generation source search and display device configured as described above with reference to the flowchart of FIG. Step 1 in this flowchart
(Hereinafter, the step is referred to as S.) is processing until the detection data from each of the measurement units 2 to 4 and the observation unit 5 is collected by the second signal control unit 13, and S2 to S11 are computers of the observation unit 5. 14 is a process performed.

In S1, the detector 6 of each of the measuring units 2 to 4
The voltage value and the current value detected at are converted from the optical signal to the electric signal by the O / E converter 7, and the first to the twentieth order (the fundamental wave is set to 60 Hz, and the fundamental wave is 20 times the fundamental wave) by the amplification filter 8. Only frequency components up to a certain 1.2 Kz) are extracted. Further, this signal is input to the A / D converter 9 and subjected to A / D conversion, and thereafter, detection data is sequentially collected by the first signal control unit 10 including the CPU. Then, the detection data is input to the second signal control unit 13 via the first and second wireless devices 11 and 12.

In step S2, the computer 14 converts the detection data input via the second signal control unit 13 into voltage waveform data and current waveform data and records the converted data. In S3, the waveform data is subjected to an FFT operation (Fast Fourier Transform) to calculate a real value and an imaginary value of each order. In S4, the computer 14 calculates the absolute value of each order based on the real and imaginary values. In S5, the computer 14 calculates the phase angle of each order based on the real and imaginary values. In S6 and S7, the content rate and the total harmonic amount (distortion rate) of each order are calculated based on the absolute value. S
At 8, an effective value is calculated based on the amplitude of each order.

In step S9, the computer 14 calculates a real part and an imaginary part of the frequency characteristic based on the voltage waveform in each order, and a real part and an imaginary part of the frequency characteristic based on the current waveform collected on the same time axis as the voltage waveform. , The product of both real parts and both imaginary parts, and U
The active power of the phase, V phase, and W phase is calculated. In S10, the computer 14 calculates the sum of the active power for each order in each of the measuring units 2 to 4. If the sum of the active power is a positive value, the computer 14 determines that the harmonic generation source is on the power supply side, and if the total value is a negative value, determines that the harmonic generation source is on the load side.

In S11, the computer 14 displays a display section 25 on the CRT display 17 based on the direction of each harmonic generation source obtained in S9 and the active power of each harmonic. At the same time, the printer 15 outputs numerical data of the active power of each harmonic. Then, as shown in FIG. 1, the measurer looks at the arrow on the display unit 25 to determine where the harmonic generation source is. Therefore, the measurer can display the third harmonic by a display unit 2 shown by a solid line in FIG.
It can be determined from the arrow 5 that the load is present in the load display unit 24, it is possible to determine that the fifth harmonic indicated by the two-dot chain line is generated in the load display unit 23, and the seventh harmonic indicated by the dotted line is detected as the load. It can be determined that it has occurred on the display unit 23. In addition, in the case where the arrow of the display unit 25 of each of the measurement units 2 to 4 does not indicate a specific direction, the measurer indicates the display unit 25 having the higher harmonic active power among the same orders, that is, the arrow of the long display unit 25. Judge with priority.

As described above, since the direction of the harmonic generation source and the harmonic power are displayed on the display unit 25 on the CRT display 17, it is easy to understand where the harmonic generation source is. As a result, the operator can quickly search for the harmonic source of each order by just looking at the display unit 25.

Further, since the third, fifth and seventh display units 25 are displayed in different colors, even when the multi-order display unit 25 is displayed on the CRT display 17, it is easy to recognize which order arrow is. . For this reason, the display unit 25 of a desired order can be quickly identified by the color of the display unit 25 without being confused during the operation.

It should be noted that the present invention is not limited to the above-described embodiment, and may be appropriately changed as follows without departing from the spirit of the present invention. (1) As shown in FIG. 6, the display unit 25 may be provided with a pattern or displayed by hatching.

(2) In the above embodiment, the display unit 25 is connected to the CR
Although displayed on the T display 17, it may be displayed on the printer 15, a color liquid crystal display, or the like.

(3) Any color other than the display color of the display unit 25 shown in the above embodiment may be displayed. When a monochrome liquid crystal display is used, the brightness of the display unit 25 may be changed by contrast so that the display unit 25 in each order can be identified.

(4) Numerical data of harmonic power may be displayed at the end of the display section 25 of the CRT display 17. (5) If the direction of the arrow cannot be identified from the direction of the arrow on the display unit 25, the computer 14 may control the display unit 25 having the highest harmonic power of the order to be searched to blink.

[0029]

As described above in detail, according to the first aspect of the present invention, the generation direction at the branch point of the dendritic distribution line can be easily determined without spending much time determining the harmonic generation source. It has an excellent effect that it can be performed.

According to the second aspect of the present invention, there is an excellent effect that the display unit for each order displayed on the display means can be easily determined.

[Brief description of the drawings]

FIG. 1 is a front view of a CRT display according to an embodiment.

FIG. 2 is an overall configuration diagram of the harmonic search device.

FIG. 3 is a block diagram showing a measurement unit.

FIG. 4 is a block diagram showing an observation unit.

FIG. 5 is a flowchart for explaining measurement of a harmonic.

FIG. 6 is a front view of a CRT display showing another embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Distribution line, 2-4 ... Measurement part, 6 ... Detector, 11 ... 1st radio | wireless device (transmission means), 12 ... 2nd radio | wireless device (reception means),
14 ... Computer (arithmetic means, the direction determination hand stage), 17
... CRT display (display means), 25 ... Display unit

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Tsuzuki 1st character small needle in Inuyama City, Aichi Prefecture Energy Support Co., Ltd. (56) References JP-A-4-301777 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01R 31/00 G01R 31/08 G01R 23/20 G01R 29/00

Claims (2)

(57) [Claims] 1. A detecting unit for detecting a phase voltage and a phase current of a distribution line, a measuring unit including a transmitting unit for wirelessly transmitting a detection signal of the detecting unit, a receiving unit for receiving the detection signal, and the receiving unit Calculating means for calculating the harmonic power for each harmonic order based on the received signal from the first and second direction determining means for determining the direction of the harmonic generation source; and the harmonic calculated by the calculating means and the direction determining means. And an observation unit having display means for displaying the power and harmonic generation source directions, and the measurement unit is installed on each distribution line forming a branch point of the dendritic distribution line, and the measurement units are installed. It is harmonic source exploration display device and displaying the harmonic source direction and magnitude of the harmonic power of each order on the display unit of the arrow-shaped at the point. 2. The display apparatus according to claim 1, wherein the display section displayed by said display means is displayed in a pattern or color identifiable by harmonic order. .