KR20190033250A - Apparatus for assuring accuracy of harmonic frequency power, Method thereof, and Computer readable storage medium having the same - Google Patents

Abstract

The present invention relates to a harmonic wave power calculation technique and, more specifically, to a harmonic wave power calculation accuracy assurance device capable of extending accuracy assurance of harmonic wave power (reactive power) calculation to a range of degrees, a method thereof, and a computer readable storage medium storing the method. According to the present invention, when a sampling rate for extracting a value of a voltage and a value of a current per unit time is assumed as the same, accurate harmonic wave power (particularly, harmonic and reactive), which has up to a harmonic wave degree of at least twice (or more), can be calculated. Therefore, the accuracy of a power factor and the accuracy of apparent power can be increased. The harmonic wave power calculation accuracy assurance device includes a fundamental wave removal filter, a harmonic wave selection filter, a fundamental wave identification module, a passing signal generation module, a first sample extraction module, a second sample extraction module, a first average power calculation module, a second average power calculation module, and a total power calculation module.

Description

TECHNICAL FIELD The present invention relates to a harmonic power accuracy assurance device, a method thereof, and a computer-readable storage medium storing the method.

More particularly, the present invention relates to a harmonic power accuracy assurance device capable of expanding the accuracy of harmonic power (reactive power) calculation to a range of degrees, a method thereof, and a computer readable storage medium storing the method Capable storage medium.

In a general power quality measuring apparatus, there is a restriction that the sampling rate per unit time is increased in order to measure the reactive power as the harmonic order increases in order to calculate the harmonic reactive power.

Several studies have already revealed that harmonics shorten the life of many loads and make the system unstable. Especially, as the distributed power supply, the electric car charging station, and the use of the inverter are rapidly increased, harmonics are becoming more and more important to control the instability of the system.

However, it is difficult to economically implement the function of calculating the transmission and reverse power of the reactive power due to the harmonic current because it requires high hardware level for the device for calculating the amount of power. In the end, the harmonics of the whole system are increasing rapidly, but considering the economical efficiency, it is not easy to realize the amount of the harmonics in the electric power meter for power trading.

Technically, when the reactive power due to the harmonics is obtained, there is a restriction that the sampling number per unit time for the voltage current must be increased in direct proportion as the harmonic order increases. This is because when the reactive power is obtained, the voltage and current values must be sampled and calculated with a visual difference corresponding to a phase difference of 90 degrees between the voltage and the current.

Here, the reason why the number of samples is increased is that as the n-th order (higher order harmonic) becomes, the time difference corresponding to the phase difference of 90 degrees between the voltage and current decreases. Therefore, the number of sampling times per unit time increases in order to distinguish the time difference. This, in turn, means that the number of samples to be processed by the hardware increases, which is a big limitation.

Also, in low-performance devices for power quality measurement, there is THD (Total Harmonics Distortion) function that does not reflect the concept of voltage-current phase difference, but there is no function to check the amount of harmonic power generation. As mentioned above, since the phase difference must be reflected in order to directly obtain the reactive power amount, a high sampling rate is required, which requires high hardware performance.

In particular, the low-voltage electronic watt-hour meter, which includes a part of the power quality measurement function, does not have the function of confirming the generation / consumption (in particular, invalid) of the active power and the reactive power due to the harmonics due to hardware constraints. However, it does not reflect the phase concept, but the computational algorithm uses THD function which is relatively simple.

In fact, it is simple to calculate the effective power due to the harmonics, and many of them have been proposed in the prior art. The principle is briefly explained as follows: Since the fundamental wave is removed from the original signal (BPF, one band-pass filter is required) and then the voltage and current signals are sampled at the same point in time, only the average (dozens of cycles of fundamental waves) to be.

However, in order to accurately calculate the reactive power due to the harmonics, it is necessary to calculate the reactive power by multiplying the voltage and the current by a phase difference of 90 degrees, that is, a value sampled at another point in time. The harmonics of the fundamental wave are n times longer and the time is shorter). The voltage and current signals should be extracted for each harmonic order through a filter, and then the signal should be sampled and calculated.

In order to filter only specific harmonic orders (frequency bands), it is necessary to design a hardware filter by switching the frequency axis and the time axis or by the number of harmonic orders to be observed by each order. If there are more, there will be a constraint such as a surge in the amount of computation,

It is very difficult to obtain the total amount of reactive power.

Therefore, as mentioned above, THD (total harmonic distortion factor,%) technique is widely used to monitor the influence on harmonics. This can be expressed by the following equation.

However, if you only look at the THD for electrical quality, it is difficult to interpret the system effect on the harmonics perfectly. The reason is that the THD technique is missing the phase concept between voltage and current.

In other words, THD alone shows how much the voltage and current harmonics are generated relative to the fundamental wave (%). However, since there is no phase concept, it is not known how much harmonic active power or reactive power is consumed or supplied due to harmonic voltage current.

It is not known how the harmonics affect the power factor of the system based on the fundamental wave (60 h in Korea). Accordingly, it is impossible to know how much harmonic current / reactive power is supplied to the customer by the electric sales company as to whether the customer supplies the harmonic current / reactive power to the system.

More precisely, if there is no phase difference between the voltages and currents of each order harmonic having a certain magnitude (exactly matched), the active power will be further consumed in the system due to harmonics for that system. In other words, it has a power factor increase effect from the customer's point of view.

On the other hand, if the harmonic voltage is higher by 90 degrees than the current, the reactive power will be consumed in the system due to the harmonics. In other words, there is an effect of lowering the power factor from the viewpoint of the customer.

In other words, even if the THD (%) is the same, the influence from the actual customer / system point of view may be different. Therefore, it is very important to measure the active power and the reactive power due to the harmonics from the viewpoint of system management.

Therefore, it is possible to accurately calculate the amount of wired / reactive power (in particular, the amount of reactive power) due to harmonics

The need is increasing.

1. Korean Patent Publication No. 10-2014-0013465 2. Korean Patent No. 10-1207495 3. Japanese Laid-Open Patent No. 1995-198764

The present invention has been proposed in order to solve the problem according to the above background art, and it is an object of the present invention to provide a harmonic power accuracy which can calculate accurate harmonic power (in particular, harmonic ineffectiveness) up to a harmonic degree of at least about 2 times (or more) And a computer-readable storage medium storing the method.

The present invention also provides a harmonic power accuracy assurance device capable of simultaneously reducing the amount of computation by obtaining reactive power for harmonics that may be sampled at the same time (timing), a method thereof, and a computer readable storage medium storing the method There are other purposes to provide.

Further, the present invention provides a harmonic power accuracy assurance device capable of calculating harmonic power by firmware (software) update at a hardware level of a commercially available electric quality meter without requiring high-performance hardware for a calculation amount, thereby enabling careful system management. And a computer-readable storage medium storing the method.

The present invention also provides a harmonic power accuracy assurance device capable of implementing an algorithm that can obtain the amount of energy without increasing the number of samples per unit time unconditionally in order to economically calculate the amount of reactive power for higher harmonics, It is another object to provide a computer-readable storage medium storing a method.

The present invention provides a harmonic power accuracy assurance device capable of calculating accurate harmonic power (in particular harmonic ineffectiveness) up to a high harmonic degree at least about two times (or more) in order to achieve the above-described problems.

The harmonic power accuracy assurance apparatus includes:

A fundamental wave removing filter for removing a fundamental wave from the original signal received from the input module to extract a plurality of harmonics;

A harmonic selection filter that deletes or extracts harmonics equal to or higher than a predetermined reference among the plurality of harmonics to generate a first community harmonic composed of specific order harmonics below the reference;

A fundamental wave identification module for identifying a fundamental wave in the original signal;

A transit signal generation module for generating a second community harmonic composed of specific orders except for the fundamental wave and the first community harmonic in the original signal;

A first sample extraction module for generating a first community signal composed of a first plurality of voltage and current samples through sampling from the one community harmonic;

A second sample extraction module for generating a second group signal comprising a second plurality of voltage samples and a second plurality of current samples through sampling from the second community harmonic;

A first average power calculation module for calculating a first valid and an invalid average power based on the first cluster signal;

A second average power calculation module for calculating a second valid and an invalid average power based on the second cluster signal; And

And a total power calculation module calculating the total power and the power factor using the first valid and invalid average power and the second valid and invalid average power.

The harmonic power accuracy assurance apparatus may further include a second harmonic generator for generating a third harmonic of harmonics of a harmonics level higher than the reference by generating a third group signal composed of a third plurality of voltage samples and a third plurality of current samples, Extraction module; A third average power calculation module for calculating a set difference ideal power set by using the third cluster signal and a preset difference over a preset difference using the third cluster signal; And a specific order over total power calculating module for calculating a set total difference total power and a power factor using the set difference ideal apparent power and the set difference over active power.

The set difference ideal power may be a product of a Root Means Square (RMS) value of a voltage sample of a third plurality and a RMS value of a voltage sample of a third plurality.

Also, the set-point abnormal power may be a value obtained by averaging the products of the third plurality of voltage samples and the third plurality of current samples at the same time.

In addition, it is preferable that the setting difference is 32 or more.

시간 지연되는 제 1 다수의 전류 샘플의 각각의 곱을 평균한 값과 상기 제 2 다수의 전압 샘플과 상기 기본파 기준 미리 설정되는

의 일정각도 시간 지연되는 제 2 다수의 전류 샘플의 각각의 곱을 평균한 값의 합인 것을 특징으로 할 수 있다.In addition, the reactive power may be determined based on the voltage samples of the first plurality,

Averaging a product of each of the first plurality of time samples delayed and a second multiple of the voltage samples and the fundamental

And a value obtained by averaging each product of the second plurality of current samples delayed by a predetermined angle of time.

로써 180도, 90도, 45도, 22.5도, 11.25도, 5.625도 등인 것을 특징으로 할 수 있다.In addition, the predetermined angles are sequentially determined as a fundamental wave reference

180 degrees, 90 degrees, 45 degrees, 22.5 degrees, 11.25 degrees, 5.625 degrees, and the like.

Also, the average value may be inverted to -1.

Also, the effective power is calculated by averaging a product of each of the first plurality of current samples at the same time as the first plurality of voltage samples and a second plurality of current samples at the same time as the voltage samples of the second plurality And a value obtained by averaging the product of the two values.

The sampling may be performed every 0.000262416 seconds to acquire 64 samples in one cycle.

Further, the first harmonic is crowded, when sampled at 2 ⁿ number of times per second (second) 1 + 4n, 2 + 8n, 4 + 16n, 8 + 32n ... 2 k-1 + (2 K + 1 × n + ¹ , 2 + ^k + ¹ , 2 + 2, ^k + ^{1, k} + ^{1, K + 1} x n), where K is an integer of ¹ , and is characterized in that it is generated by filters having a characteristic capable of filtering a harmonic order.

On the other hand, another embodiment of the present invention provides a method of generating a fundamental wave, comprising: (a) extracting a plurality of harmonics by removing a fundamental wave from an original signal received from an input module; (b) generating a first community harmonic composed of specific order harmonics below the reference by removing or extracting harmonics of a predetermined reference among the plurality of harmonics; (c) the fundamental wave identification module identifies the fundamental wave in the original signal; (d) generating a second community harmonic composed of specific order harmonics except for the fundamental wave and the first community harmonic in the original signal; (e) a first sample extraction module generating a first population signal consisting of a first plurality of voltage and current samples through sampling from the one community harmonic; (f) generating a second cluster signal comprising a second plurality of voltage samples and a second plurality of current samples through sampling from the second cluster harmonic; (g) calculating a first valid and an invalid average power based on the first cluster signal; (h) a second average power calculation module calculating a second valid and invalid average power based on the second cluster signal; And (i) calculating a total power and a power factor using the first valid and invalid average power and the second valid and invalid average power, the total power calculation module being capable of providing a harmonic power accuracy guarantee method have.

In the method, the third sample extracting module extracts a third plurality of voltage samples and a third plurality of currents through sampling from a third community harmonic having harmonics above the reference, after the step (b) Generating a third cluster signal comprising a sample; A third average power calculation module for calculating a predetermined difference power or more and a predetermined difference or more effective power using the third cluster signal and a third average power calculation module using the third cluster signal; And calculating the total power and power factor over the set difference using the set power ideal power and the set power greater than the power difference set by the specific power total power calculation module.

On the other hand, another embodiment of the present invention can provide a computer-readable storage medium storing a program code for implementing a harmonic power accuracy assurance method.

According to the present invention, when it is assumed that the sampling rate for extracting the voltage and current value per unit time is the same, accurate harmonic power up to a harmonic degree of at least about 2 times (or more) ) Can be calculated. This improves the accuracy of the power factor and the accuracy of the apparent power.

In addition, because reactive power is calculated with accurate and low computational power in the fundamental wave and harmonic range, it is possible to accurately calculate the apparent power based on the reactive power and the reactive power even with low performance hardware. Accurate calculation of apparent power and effective power also improves the accuracy of the power factor that can be accurately calculated.

Because the harmonics are calculated more precisely, the metering / measurement reliability up to the higher order harmonics is higher than the conventional one (about 2 times), and it is possible to manage the system more closely.

Another advantage of the present invention is that it can be applied to all apparatuses for measuring electric quality (electric energy), and it is highly possible that the total amount of the harmonic power can be economically judged when the watt hour meter is applied have.

In addition, another effect of the present invention is that it is possible to make a reasonable charge that applies a more expensive charge to the cause of harmonic generation because the subject generating the harmonic becomes clear. In other words, with the adoption of harmonic pricing system, all customers (especially power generation companies) will make efforts to manage harmonics, which will improve the stability of the system.

In addition, if customers who generate a lot of harmonic power are disadvantaged in terms of fees, the harmonics customers will try to limit the harmonic power, which will improve the stability of the whole system. It is possible to expect a virtuous cycle effect that not only stable system operation but also load life is increased.

Further, as another effect of the present invention, in order to economically calculate the amount of reactive power for higher harmonics, the amount of the reactive power can be obtained without unconditionally increasing the number of samples per unit time. To put it more simply, the same physical performance can guarantee the yield of reactive power / reactive power up to a higher harmonic order than conventional.

1 is a structural block diagram of a harmonic power accuracy assurance apparatus according to an embodiment of the present invention.
2 is a detailed block diagram of the harmonic selective filter 120 shown in FIG.
3 is a detailed block diagram of the first sample extraction module 140-1 shown in FIG.
4 is a detailed block diagram of the total power calculation module 160-1 shown in FIG.
FIG. 5 is a detailed block diagram of the specific-order over-total power calculation module 160-3 shown in FIG.
6 is a flowchart illustrating a process of ensuring the accuracy of the harmonic power according to the temporary example of the present invention.
FIGS. 7 to 9 are examples of sampling and filtering the actual guarantee process shown in FIG. 6 at 4 kHz.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Like reference numerals are used for similar elements in describing each drawing. The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. The term "and / or" includes any combination of a plurality of related listed items or any of a plurality of related listed items.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Should not.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout.

In one embodiment of the present invention, the higher harmonics are used to obtain the reactive power

The time difference between the voltage sampling time and the current sampling time must be shortened.

It is to avoid the basic constraint as much as possible.

Also, in one embodiment of the present invention, one or more harmonic orders that may be sampled at the same time may be calculated simultaneously to reduce the number of calculations.

Also, it is aimed to reduce the number of calculations in order to obtain the reactive power by selecting the method of continuously excluding the harmonic orders obtained from the reactive power sequentially from the original signal.

1 is a block diagram of a harmonic power accuracy assurance apparatus 100 according to an embodiment of the present invention. Referring to FIG. 1, an input module 110 for receiving an original signal, a fundamental wave removing filter 120 for removing a fundamental wave from a circular signal to extract a plurality of harmonics, A harmonic selective filter (120) for generating a first community harmonic composed of specific order harmonics below the reference, a fundamental wave identification module (170) for identifying a fundamental wave in the original signal, And a second signal generating module 180 for generating a second community harmonics except for the first community harmonics, a second community noise generating module 180 for generating a first community signal including a first plurality of voltage and current samples through sampling from the first community harmonics, 1 sample extraction module (140-1), a second cluster neuron consisting of a second plurality of voltage samples and a second plurality of current samples through sampling from the second community harmonic A first average power calculation module 150-1 for calculating a first effective and an ineffective average power based on the first cluster signal, A second average power calculation module 150-2 for calculating a second effective and an invalid average power based on the first and second effective and ineffective average powers, The total power calculation module 160-1, and the like.

시간 지연된 전류 샘플(값)의 곱을 평균한 값이다.The first average power calculation module 150-1 also has a function of calculating average values using the first plurality of voltage samples, the first plurality of current samples, the second plurality of voltage samples, and the second plurality of current samples . That is, the voltage sample (value)

Time delayed current samples (values).

시간 지연되는 제 1 다수의 전류 샘플의 각각의 곱을 평균한 값과 상기 제 2 다수의 전압 샘플과 상기 기본파 기준

시간 지연되는 제 2 다수의 전류 샘플의 각각의 곱을 평균한 값의 합이 된다.In other words, the reactive power is determined by the voltage samples of the first plurality and the fundamental wave criterion

Averaging a product of each of the first plurality of current samples delayed and a second plurality of voltage samples,

The sum of the products of the respective products of the second plurality of current samples delayed by time.

That is, the total power calculation module 160-1 calculates the final reactive power by summing the average values of the respective reactive power calculated in the first average power calculation module 150-1.

Also, the effective power is calculated by averaging a product of each of the first plurality of current samples at the same time as the first plurality of voltage samples and a second plurality of current samples at the same time as the voltage samples of the second plurality And the average of the products of the two products.

That is, the total power calculation module 160-1 calculates the final effective power by summing the average values of the respective active powers calculated in the first average power calculation module 150-1.

Although the first and second average power calculation modules 150-1 and 150-2 and the total power calculation module 160-1 are shown separately in FIG. 1 for the sake of understanding, It is possible. That is, the first power calculation module 150-1 and / or the second average power calculation module 150-2 may be integrated into the total power calculation module 160-1.

 Of course, the harmonic power accuracy assurance apparatus 100 generates a third cluster signal composed of a third plurality of voltage samples and a third plurality of current samples through sampling from a third cluster harmonic of harmonics above the reference A third sample extracting module 140-3 for calculating a third difference value between the first difference signal and the third difference signal, Module 150-3, a specific order over total power calculation module 160-3 that calculates the total power and power factor over the set difference using the set difference ideal power and the set difference or more effective power, and the like .

Here, the set abnormal power is a product of a root mean square (RMS) value of a voltage sample of a third plurality and a RMS value of a voltage sample of a third plurality.

The set abnormal power may be a value obtained by averaging the products of the third plurality of voltage samples and the third plurality of current samples at the same time.

At this time, the setting difference may be 32 or more.

2 is a detailed block diagram of the harmonic selective filter 120 shown in FIG. Referring to FIG. 2, the harmonic selective filter 120 includes a harmonic erasure filter 210 for eliminating harmonics over a maximum harmonic observation range, a harmonic extraction filter 220 for extracting harmonics over a maximum harmonic observation range, and the like . Therefore, the harmonic erasure filter 210 passes harmonics below the maximum harmonic observation range.

3 is a detailed block diagram of the first sample extraction module 140-1 shown in FIG. Referring to FIG. 3, the first sample extracting module 140-1 includes a cluster voltage pass filter block 310-1 for passing only specific voltages from the cluster harmonics to generate a cluster voltage, A population sampling module 320-1 for generating samples, a cluster current passing filter block 310-2 for generating a cluster current by passing only specific currents from the cluster harmonics, and a current sample from the cluster current through sampling A current sampling module 320-1, and the like.

A sample means to obtain its sign and magnitude at an arbitrary point in time for an arbitrary signal.

2 + 8n, 4 + 16n, 8 + 32n ... ^2k when sampled at ²ⁿ in a cycle, the cluster voltage transit filter block 310-1 and the cluster current transit filter block 310-2, ^{-1 + (2 K + 1 ×} n), the filter having a property that can filter out the harmonic order of the integer and where K≥1 3 + 4n, 6 + 8n, 12 + 16n, 24 + 32n ... 3 × 2 ^k-1 + (2 ^{K + 1} × n), where K is an integer of ¹ .

The filter, of course, can be tailored to suit the design as the number of samples per cycle changes.

In one embodiment of the present invention, it is possible to calculate the power up to about two times higher harmonic order even at the same sampling rate. For the sake of understanding, the meaning of acquiring 64 samples per cycle in a 60-hz frequency environment means that sampling is performed every 0.000262416 sec.

1 / 60Hz x 1/64 sample = 0.000262416 ... sec, it means that sampling (signal acquisition) should be performed every about 0.000262416sec to acquire 64sample in one cycle.

On the other hand, a computing unit having a 4 kHz sampling rate capability is 1/4 khz = 0.00025 sec. Therefore, if sampling is performed fastest, data can be acquired every 0.00025 sec. This means that the sampling interval is faster than about 0.000262416 sec, so you can acquire 64 samples or more in a cycle without difficulty.

However, the reason why the ineffective power of 17 harmonics can not be obtained at the resolution of 4 kHz is that the time of 90 ° phase difference of 17 harmonics is 1 / 60Hz × 90/360 × 1/17 _order = 0.000245 ... sec, (Fast, precise) value that is less than the highest precision interval of 0.00025 sec. Therefore, the reactive power due to harmonics in the 17th order can not be obtained with the 4 kHz resolution.

Because of this, power factor and apparent power can not be precisely shown in a chain. However, in one embodiment of the present invention, sampling is performed not only at 90 degrees but also at (180n + 90) degrees, (360n + 90) degrees, The reason is that all the signals are implemented as the sum of the SIN function and the COS function, so that the same value repeatedly appears at a point of 360 ° difference as a periodic function. Of course, a 180-degree-difference signal can perform inverting (transcoding).

17 Harmonics In detail, the value at 1,530 degrees (360X4 + 90 degrees) of the sinusoidal wave (sin, cos) from the 17 harmonic viewpoint is the same as the 90 degree value from the point of view of 17 harmonics. 17 is to sample at 1,530 degrees of 17 harmonics without sampling at 90 degrees which is a harmonic point of view. That is, the concept of obtaining the reactive power by acquiring the voltage current value at a visual difference corresponding to the phase difference of 1,530 degrees (360n + 90), rather than obtaining the voltage current value with a visual difference corresponding to the phase difference of 90 degrees between voltage and current to be.

The visual difference corresponding to 1,530 degrees of harmonics is 1 / 60Hz × (90 × 17) / 360 × 1/17 _order = 0.0041666 ... sec. This value is the fastest sampling rate of the arithmetic unit with 4 kHz sampling rate performance Is greater than 0.00025 sec (because it is slow), it is possible to calculate the reactive power without difficulty.

As a general technique, the reactive power due to 17 harmonics can not be obtained while having a sampling rate of 4 kHz. By applying this principle, it is possible to obtain 17 harmonic reactive power, and it is possible to calculate the power up to about two times higher harmonic order even at the same sampling rate.

It is also possible to reduce the amount of computation by filtering several different harmonic orders simultaneously to obtain reactive power. That is, in one embodiment of the present invention, several signals having harmonic orders different from each other are filtered at the same time in order to reduce computation and obtain reactive power.

Further, in order to obtain the total reactive power of the harmonic orders to be observed in the related art, the reactive power has to be obtained for each harmonic order for each harmonic order. Accordingly, there is a problem that the number of operations is increased by repeating the algorithm as many times as the number of harmonic orders to be observed with the same algorithm.

In one embodiment of the present invention, the harmonics, which may be sampled at the same time (timing), simultaneously calculate the reactive power to reduce the amount of computation. The drawing showing this is shown in Figs. Assuming that there is a signal obtained by adding a voltage current having an A-order (for example, a fundamental wave) to a voltage current having a B-order (for example, 5 harmonics) and a C-order (for example, 9 harmonics) The current and the voltage at the point where the phase difference is 90 degrees in each of the A-order and the B-order C-order points should be obtained.

On the other hand, when the voltage fundamental wave is sin (t) and the current fundamental wave is sin (t + φ), the voltage 5 harmonic can be expressed by sin (5t) and the ninth harmonic can be expressed by sin (9t). Here, A, B, and C order values are 90 degrees when viewed from the fundamental wave.

-> order A = fundamental wave: sin (-90) = - 1

-> B order = 5 Harmonic: sin (-5 * 90) = sin (-450) = sin (-360-90) = sin

-> C order = 9 harmonic sin (-9 * 90) = sin (-810) = sin (-720-90) = sin

What this means is that when sampling a voltage value 90 times faster than the fundamental wave, the 5th harmonic and the 9th harmonic are normally sampled normally at a value of -1 at the 5th harmonic and at a rate of 90 degrees at the 9th harmonic current .

Conventionally, when sampling 5 harmonic voltages, it is necessary to sample the voltage value 18 times faster than the 5 harmonic current (-18 * 5 = -90) from the viewpoint of the fundamental wave. 5 From the harmonic viewpoint, 5 Harmonic Reactive power was obtained 18 times faster in terms of fundamental wave.

In the embodiment of the present invention, even when the 5th harmonic reactive power is obtained, the reactive power is obtained by obtaining a value 90 degrees higher than the fundamental wave (5 * 90 = 450 degrees from the 5th harmonic viewpoint) Values are the same)

Conventionally, when sampling the 9 harmonic voltage, it is necessary to sample the voltage value 10 times faster than the 9 harmonic current (-10 * 5 = -90) from the viewpoint of the fundamental wave. (9 * 90 = 720 + 90 = 810 degrees in terms of 9 harmonics) in the fundamental wave view in the embodiment of the present invention. However, in the embodiment of the present invention, And obtains the reactive power, so that the algorithm is implemented by the corresponding method.

In order to obtain the reactive power of the higher harmonics, it is not necessary to calculate the time difference between the acquisition time of the voltage and the current value at the time difference corresponding to the phase difference of 90 degrees from the harmonic viewpoint, And 360n + 90 degree phase difference, respectively, so as to avoid unconditionally increasing the sampling frequency for the reactive power of the higher harmonics.

4 is a detailed block diagram of the total power calculation module 160-1 shown in FIG. Referring to FIG. 4, the total power calculation module 160-1 includes a reactive power calculation module 410 and an active power calculation module 420. On the other hand, an inverter 401 is configured to perform inverting (sign conversion) in order to generate a signal having a phase difference of 180 degrees. In a discrete environment, the AC voltage current values that instantaneously change in the universal technology of the reactive / reactive power measurement are respectively sampled, and the voltage and current are sampled and multiplied for calculating the effective power, I ask. This can be expressed by the following equation.

On the other hand, in order to calculate the reactive power, the reactive power is calculated by multiplying the current value sampled at the point A and the voltage sample value (the time corresponding to the phase difference of 90 degrees) temporally before the point A at the sampling point.

As a result, the fact that the value obtained by multiplying the voltage and the current sample value of the time difference corresponding to the 90-degree phase difference becomes the reactive power can be proved by the equation and is a universal technology presented in many existing documents. Therefore, .

FIG. 5 is a detailed block diagram of the specific-order over-total power calculation module 160-3 shown in FIG. Referring to FIG. 5, the specific order over total power calculating module 160-3 includes an nth order ideal apparent power calculating module 510 for calculating the nth order ideal apparent power and a nth order ideal ideal power calculating module And a power calculation module 520.

6 is a flowchart illustrating a process of ensuring the accuracy of the harmonic power according to the temporary example of the present invention. Referring to FIG. 6, the input module (110 in FIG. 1) outputs the original signal (step S601). Thereafter, the fundamental wave elimination filter 120 removes the fundamental wave from the original signal received from the input module 100 to extract a plurality of harmonics (step S602). Of course, the fundamental wave is removed by the fundamental wave elimination filter 120, and the fundamental wave identification module 170 identifies the fundamental wave in the original signal (step S603).

Thereafter, the harmonic selective filter 130 deletes and / or extracts harmonics of a predetermined reference or more among the plurality of harmonics, and generates a first community harmonic having specific harmonics below the reference (step 611).

The pass-through signal generation module 180 generates a second community harmonic except for the fundamental wave and the first community harmonic identified in the original signal (step S630).

에 해당하는 시간 지연된 전류 샘플값과 동일 시점의 전류 샘플값을 각 각 산출한다(단계 S640-1, S640-2).Thereafter, the first sample extracting module 140-1 generates a first cluster signal consisting of a first plurality of voltage samples and a first plurality of current samples through sampling and a second plurality of sampling signals from the second cluster harmonic (S621-1, S621-2, S622-1, S622-2, and S640-1), which are composed of the voltage samples of the first and second pluralities of current samples. Subsequently,

(Step S640-1, step S640-2). The current sample value at the same time as the current sample value at the same time is calculated.

Thereafter, the total power calculation module 160-1 calculates the reactive power and the active power using the first cluster signal and the second cluster signal (steps S651, S652, S661, and S662).

시간 지연되는 제 1 다수의 전류 샘플의 각각의 곱을 평균한 값과 상기 제 2 다수의 전압 샘플과 상기 기본파 기준 미리설정되는

만큼 일정 각도에 해당하는 시간 지연되는 제 2 다수의 전류 샘플의 각각의 곱을 평균한 값의 합이 된다. 물론, 평균한 값은 -1로 인버팅되는 과정이 수행될 수 있다(단계 S606).Herein, the reactive power is a sum of the voltage samples of the first plurality and the fundamental wave reference

Averaging a product of each of the first plurality of time samples delayed and a second multiple of the voltage samples and the fundamental

And the average of the products of the second plurality of current samples delayed by a predetermined angle. Of course, the process of inverting the averaged value to -1 may be performed (step S606).

Wherein the effective power is calculated by averaging a product of each of the first plurality of current samples at the same time as the first plurality of voltage samples and a second plurality of current samples of the second plurality of current samples at the same time as the voltage samples of the second plurality It is the sum of the products averaged.

On the other hand, the third sample extracting module 140-3 generates a third plurality of voltage samples and a third plurality of current samples through sampling from a third community harmonic composed of harmonics above the reference by steps S611 and S612 Steps S670-1 and S670-2).

Thereafter, the third average power calculation module 150-3, the specific order over total power calculation module 160-3, and the third and fourth plurality of voltage samples, (Step S680-1, 680-2, S691, and S692) using the third plurality of current samples and the third plurality of current samples.

The apparent power is determined by multiplying the root mean square (RMS) value of the voltage sample of the third plurality by the RMS value of the voltage sample of the third plurality. Also, the effective power is the average of the product of the voltage samples of the third plurality and the current samples of the third plurality at the same time.

FIGS. 7 to 9 are examples of sampling and filtering the actual guarantee process shown in FIG. 6 at 4 kHz. Referring to FIGS. 7 to 9, 64 samples are sampled in one cycle and classified by (1, 5, 9, 13, 17) filters and (2, 10, 18, 26, 34) It is an example.

Therefore, in one embodiment of the present invention,

By utilizing the periodicity of the sinusoidal wave without utilizing the phase difference, the constraint can be avoided by utilizing the phase difference of 90 + 180 = 270 degrees or 90 + 360 = 450 degrees. Applying one embodiment of the present invention with a computing unit having the same resolution (Sampling Rate (kHz)) through this, the maximum harmonic order for guaranteeing the amount of power is about twice as high as the conventional one (exactly two times - one order = ).

Therefore, if the generation of wired / reactive power due to harmonics or the function of checking the consumption amount is implemented without improving the hardware performance, the system management can be closely examined. Also, the power factor and the measurement reliability will be enhanced by guaranteeing the power for higher harmonics.

The term "module" or the like in the description means a unit for processing at least one function or operation, and may be implemented by hardware, software, or a combination of hardware and software.

(DSP), a programmable logic device (PLD), a field programmable gate array (FPGA), a processor, a controller, a microprocessor, and the like, which are designed to perform the above- , Other electronic units, or a combination thereof. In software implementation, it may be implemented as a module that performs the above-described functions. The software may be stored in a memory unit and executed by a processor. The memory unit or processor may employ various means well known to those skilled in the art.

The method of ensuring harmonic power accuracy according to the present invention can be implemented in the form of a program instruction that can be executed through various computer means and recorded in a computer readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination.

The program instructions recorded on the medium may be those specially designed and constructed for the present invention or may be available to those skilled in the art of computer software. Examples of the computer-readable recording medium include magnetic media such as a hard disk, a floppy disk, and a magnetic tape; optical media such as CD-ROM and DVD; magnetic recording media such as a floppy disk; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like.

The medium may be a transmission medium such as an optical or metal line, a wave guide, or the like, including a carrier wave for transmitting a signal designating a program command, a data structure, or the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

100: Harmonic power accuracy assurance device
110: input module
120: Basic Wave Excision Filter
130: Harmonic selective filter
140-1: First sample extraction module 140-2: Second sample extraction module
140-3: Third sample extraction module
150-1: first average power calculation module 150-2: second average power calculation module
150-3: Third Average Power Calculation Module
160-1: total power calculation module
160-3: Total power calculation module over a specific order
170: Basic wave identification module
180: Pass-through signal generation module

Claims (20)

A fundamental wave removing filter for removing a fundamental wave from the original signal received from the input module to extract a plurality of harmonics;
A harmonic selection filter that deletes or extracts harmonics equal to or higher than a predetermined reference among the plurality of harmonics to generate a first community harmonic composed of specific order harmonics below the reference;
A fundamental wave identification module for identifying a fundamental wave in the original signal;
A pass signal generation module for generating a second community harmonic composed of specific order harmonics excluding the fundamental wave and the first community harmonic in the original signal;
A first sample extraction module for generating a first community signal composed of a first plurality of voltage and current samples through sampling from the one community harmonic;
A second sample extraction module for generating a second group signal comprising a second plurality of voltage samples and a second plurality of current samples through sampling from the second community harmonic;
A first average power calculation module for calculating a first valid and an invalid average power based on the first cluster signal;
A second average power calculation module for calculating a second valid and an invalid average power based on the second cluster signal; And
A total power calculation module capable of calculating a total power and a power factor using the first valid and invalid average power and the second valid and invalid average power;
Wherein the harmonic power accuracy guarantee device comprises:
The method according to claim 1,
A third sample extracting module for generating a third group signal consisting of a third plurality of voltage samples and a third plurality of current samples through sampling from a third community harmonic of harmonics above the reference; A third average calculation module for calculating a predetermined difference or more apparent power using the third cluster signal and a preset difference or more effective power using a third cluster signal; And a specific order over total power calculating module that calculates a total power and a power factor over a set difference using the set difference ideal power and the set difference over active power.
3. The method of claim 2,
Wherein the setpoint ideal apparent power is a product of an RMS (root mean square) value of a voltage sample of a third plurality and a RMS value of a voltage sample of a third plurality.
3. The method of claim 2,
Wherein the setpoint difference active power is a value obtained by averaging a product of a voltage sample of a third plurality and a current sample of a third plurality at the same time point.
3. The method of claim 2,
And the set difference is 32 or more.
The method according to claim 1,
Wherein the reactive power is a sum of the voltage samples of the first plurality and the fundamental wave criterion

And a value obtained by averaging each product of the first plurality of current samples delayed by a predetermined number of times,

And a value obtained by averaging each of the products of the second plurality of current samples delayed by a predetermined angle.
The method according to claim 6,
The predetermined angles are sequentially

Wherein the harmonic power accuracy is 360 degrees, 180 degrees, 90 degrees, 45 degrees, 22.5 degrees, 11.25 degrees, and 5.625 degrees.
The method according to claim 6,
And the averaged value is inverted to -1.
The method according to claim 1,
Wherein the effective power is a product of averaging each product of a first plurality of current samples at the same time as the first plurality of voltage samples and a product of a second plurality of current samples at the same time as the voltage samples of the second plurality And the average value of the harmonic power.
The method according to claim 1,
Wherein the sampling is performed every 0.000262416sec to acquire 64 samples in one cycle.
The method according to claim 1,
The first cluster harmonic 1 + 4n, 2 + 8n, 4 + 16n, (2 K + 1 × n) 8 + 32n ... 2 k-1 + 2 ⁿ number of times when the samples to a second (second) 3 + ^2k-1 + (2K + 2n + 2n + 2n + 2n + 2n ^{+ 1} x n), where K > = ¹ , in the harmonic power accuracy guarantee device.
(a) extracting a plurality of harmonics by removing a fundamental wave from an original signal received from an input module;
(b) generating a first community harmonic composed of specific order harmonics below the reference by removing or extracting harmonics of a predetermined reference among the plurality of harmonics;
(c) the fundamental wave identification module identifies the fundamental wave in the original signal;
(d) generating a second community harmonic composed of specific order harmonics except for the fundamental wave and the first community harmonic in the original signal;
(e) a first sample extraction module generating a first population signal consisting of a first plurality of voltage and current samples through sampling from the one community harmonic;
(f) generating a second cluster signal comprising a second plurality of voltage samples and a second plurality of current samples through sampling from the second cluster harmonic;
(g) calculating a first valid and an invalid average power based on the first cluster signal;
(h) a second average power calculation module calculating a second valid and invalid average power based on the second cluster signal; And
(i) calculating a total power and a power factor using the first valid and invalid average power and the second valid and invalid average power;
Wherein the harmonic power accuracy guarantee method comprises:
13. The method of claim 12,
After the step (b)
Generating a third cluster signal comprising a third plurality of voltage samples and a third plurality of current samples through sampling from a third community harmonic of harmonics above the reference;
A third average calculation module for calculating a predetermined difference or more apparent power using the third cluster signal and a preset difference or more effective power using the third cluster signal; And
And calculating a total power and power factor over the set difference by using the set power difference ideal power and the set power difference more than the set power difference and the total power and the power factor.
14. The method of claim 13,
Wherein the setpoint ideal apparent power is a product of an RMS (root mean square) value of a third plurality of voltage samples and an RMS value of a third plurality of voltage samples.
14. The method of claim 13,
Wherein the set abnormal power is a value obtained by averaging a product of a third plurality of voltage samples and a third plurality of current samples at the same time point.
13. The method of claim 12,
Wherein the reactive power is a sum of the voltage samples of the first plurality and the fundamental wave criterion

And a value obtained by averaging each product of the first plurality of current samples delayed by a predetermined number of times,

And a value obtained by averaging each product of a second plurality of current samples delayed by a predetermined angular time corresponding to the first and second current samples.
17. The method of claim 16,
The predetermined angles are sequentially

Wherein the harmonic power accuracy is 360 degrees, 180 degrees, 90 degrees, 45 degrees, 22.5 degrees, 11.25 degrees, and 5.625 degrees.
13. The method of claim 12,
Wherein the effective power is a product of averaging each product of a first plurality of current samples at the same time as the first plurality of voltage samples and a product of a second plurality of current samples at the same time as the voltage samples of the second plurality And a mean value of the harmonic power.
13. The method of claim 12,
The first cluster harmonic 1 + 4n, 2 + 8n, 4 + 16n, (2 K + 1 × n) 8 + 32n ... 2 k-1 + 2 ⁿ number of times when the samples to a second (second) 3 + ^2k-1 + (2K + 2n + 2n + 2n + 2n + 2n ^{+ 1} x n), where K > = ¹ , and wherein the harmonic power accuracy is generated by filters having characteristics capable of filtering harmonic orders of integers where K > = ¹ . A computer-readable storage medium storing program code for implementing the harmonic power accuracy assurance method of any one of claims 12 to 19.

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