JPH04337471A - Graph display method for higher harmonics analysis data with wattmeter - Google Patents

Abstract

PURPOSE:To obtain the graph display method of higher harmonics analysis data with wattmeter. CONSTITUTION:The taken data to be measured is analyzed through a higher harmonics analyzing means 16, and among the higher harmonics analysis data after the analysis, the data having the positive polarity is displayed with bar chart of a first pattern 19, and the data having the negative polarity is displayed with bar chart of a second pattern 20, which can be discriminated from the first pattern 19, and they are output separately in order per a degree of the higher harmonics. Pattern of the bar chart output per a degree is discriminated to know that polarity of the higher harmonics analysis data of each degree is positive or negative, and analysis that a higher harmonics generating source exists in the power source side or the load side is thereby performed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for graphically displaying harmonic analysis data using a power meter.

0002

[Prior Art] Power calculation is performed using instantaneous values of voltage and current, and the power at that time is V・I・cos
It can be determined by the formula θ+V·I·cos (2ωt−θ), of which V·I·cos θ becomes the effective power value.

In this case, the phase angle θ is −90°≦θ≦90
When the power is within the range of 100°, the power is a positive value, indicating that power is being supplied from the power source to the load. In addition, the phase angle θ is 90°≦θ≦270° (−9
0°), the power has a negative value, indicating that power is being returned from the load side to the power source side.

[0004] Therefore, depending on whether the power is a positive value or a negative value, it can be determined whether the load side is consuming power or generating power. Become.

By the way, in recent years, harmonic interference has become a problem, such as equipment making abnormal noises and overcurrent relays malfunctioning.

Regarding the problem of such harmonic interference,
It is important to know whether the source of harmonics is on the power supply side or the load side, and the source can be easily determined by knowing the polarity of the power for the reason mentioned earlier. .

[0007]

[Problems to be Solved by the Invention] Normally, in a power meter, power calculation is not performed for each harmonic component (order), and the total harmonic distortion factor that is the total of harmonic components of all orders is calculated. In reality, the power is calculated as follows.

[0008] Therefore, depending on the wattmeter, it is not possible to know individual harmonic components (orders), so there is an inconvenience that harmonic analysis data for each order cannot be obtained.

[0009] Furthermore, in the case of the conventional method of outputting harmonic analysis data for each order, when each harmonic analysis data is displayed as a bar graph converted to logarithm (log) data, it is usually not correct. It is displayed as a numerical value, and it is not possible to know whether the polarity is positive or negative.Therefore, depending on this graph, it is not possible to analyze whether the harmonic generation source is on the power supply side or the load side. was there.

0010

[Means for Solving the Problems] The present invention has been made in view of the above-mentioned problems seen in the conventional methods, and its structural features include an input means for taking in data to be measured as an analog value, and A/ that converts measurement data into digital
D conversion means, memory means for storing digital data after conversion, harmonic analysis means for harmonic analysis of the measured data read from the memory means, and harmonic analysis means for harmonic analysis of the data to be measured read out from the memory means; A wattmeter comprising at least an output means for outputting harmonic analysis data in the form of a graph, and a CPU that centrally controls each of these constituent means, the harmonic analysis being performed through the harmonic analysis means. Among the data, data whose polarity is positive is displayed as a first pattern bar graph, and data whose polarity is negative is displayed as a second pattern bar graph that can be distinguished from the first pattern. The purpose is to output each item sequentially.

[0011]

[Operation] Therefore, by distinguishing the pattern of the bar graph output to the output means, it is possible to immediately know whether the polarity of the harmonic analysis data of the relevant order is positive or negative, and the harmonic generation source can be identified. You can easily analyze whether it is on the power supply side or the load side.

0012

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 shows an outline of a power meter used for carrying out the present invention, and the main body 11 of the device separately receives measured data for channels 1 to 3 as analog values via terminals T. A memory consisting of an input means 13 capable of inputting data, an A/D conversion means 14 for digitally converting the measured data of each channel separately, and a RAM etc. capable of separately storing each digital data after conversion. harmonic analysis means 16 consisting of a digital signal processor (DSP) or the like for performing harmonic analysis on the measured data read out from these memory means 15; It is provided with at least an output means 17 for outputting the harmonic analysis data obtained and a CPU 12 for controlling each of these constituent means in an integrated manner.

Note that the output means 17 in the present invention includes a CRT display, an EL display, a printer, etc., as well as a VRA for storing output data.
M is also included.

FIG. 1 is a flowchart showing a processing procedure as an embodiment of the method of the present invention, which is carried out using the wattmeter shown in FIG. According to the figure, first, "1" indicating the first order is set to a variable k prepared corresponding to harmonic orders 1 to n, and then harmonic analysis data corresponding to this "1" is set. (Hereinafter referred to as “analyze (k)
'') is a positive value (polarity) or a negative value (polarity).

[0016] At this time, "analyz" corresponding to "1"
If it is determined that "e (k)" is a positive value (polarity), a bar graph of a predetermined first pattern,
For example, as the bold line bar graph 19 in FIG. 3 is output to the output means 17 as a thin line bar graph 20.

Note that the first pattern bar graph and the second pattern bar graph in this case are not limited to the pattern example shown in FIG. 3; for example, the first pattern is a solid line bar graph and the second pattern is Any pattern, such as a bar graph with broken lines, can be adopted as long as it is possible to distinguish positive values from negative values and read them from the graph. Further, in FIG. 3, a bar graph is shown as an example in which the vertical axis is a log axis, but it is also possible to display a graph in a similar pattern with the vertical axis as a % axis.

Furthermore, the horizontal axis as the base axis in FIG. 3 is carried to the plus side in advance, and the bar graph of the first pattern showing positive values above the horizontal axis is moved downward to the negative value. This can also be done by displaying a second pattern of bar graphs representing the values.

Thus, "analy" corresponding to "1"
After the value of ``ze (k)'' is output to the output means 17 as a bar graph of either the first pattern or the second pattern, ``1'' is further added to the variable k, and this ``k+1'' is "anal" of the corresponding next order
yze (k) ” is a positive value (polarity) or a negative value (
After that, the process is sequentially repeated in the same way as when the variable k is "1".

[0020] A series of processes performed in this way are as follows:
This is repeated until it is determined that the variable k is "n" indicating the final degree, and "analyz" corresponding to "n" is
Main means 1: The value of ``e (k)'' is expressed as a bar graph of either the first pattern or the second pattern.
7, the output processing for each order of the harmonic components of the data to be measured is completed.

Since the present invention is configured as described above, the data to be measured taken in from each channel is analyzed via the harmonic analysis means 16, and then these harmonic analysis data are analyzed. As shown in FIG. 3, the harmonic analysis data with positive polarity is shown as a thick line bar graph 19 as the first pattern, and the harmonic analysis data with negative polarity is shown as the second pattern, thin line bar graph 20. can be outputted to the output means 17.

Therefore, for example, when the harmonic analysis orders are up to the 49th order, the analysis results can be output as a bar graph for each order as shown in FIG.

Furthermore, each bar graph output at this time is clearly divided into two types: thick lines indicating positive polarity and thin lines indicating negative polarity. By visually observing the different patterns, you can immediately know whether the polarity of the harmonic analysis data for each order is positive or negative, and whether the harmonic generation source is on the power supply side or the load side. Can be easily analyzed.

[0024]

[Effects of the Invention] As described above, according to the present invention, by distinguishing the bar graph pattern for each order outputted to the output means, the polarity of the harmonic analysis data of each order is positive or negative. Therefore, it is possible to easily analyze whether the harmonic generation source is on the power supply side or the load side.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing a processing procedure as an embodiment of the method of the present invention.

FIG. 2 is a configuration diagram showing an outline of an apparatus used for carrying out the method of the present invention.

FIG. 3 is an explanatory diagram showing a basic pattern of a graph diagram obtained by the method of the present invention.

FIG. 4 is a graph diagram as an example obtained by the method of the present invention.

[Explanation of symbols]

11　Device body 12 CPU 13 Input means 14 A/D conversion means 15 Memory means 16 Harmonic analysis means 17 Output means 19 Thick line bar graph 20 Thin line bar graph

Claims (1)

[Claims] [Claim 1] Input means for taking in data to be measured as an analog value, and A for converting data to be measured into a digital value.
/D conversion means, memory means for storing digital data after conversion, harmonic analysis means for harmonic analysis of the measured data read from the memory means, and harmonic analysis means for harmonic analysis of the data to be measured read out from the memory means; The harmonic analysis data analyzed through the harmonic analysis means in a power meter comprising at least an output means for outputting the harmonic analysis data as a graph, and a CPU that centrally controls each of these component means. Among them, data whose polarity is positive is displayed as a first pattern bar graph, and data whose polarity is negative is displayed as a second pattern bar graph that can be distinguished from the first pattern, for each harmonic order. A method for displaying a graph of harmonic analysis data using a wattmeter, characterized by sequentially outputting each item.