KR101082078B1 - Power system loss factor calculation method using load pattern - Google Patents

Abstract

The present invention provides a method for calculating a loss factor of a power system, the method comprising: calculating a target load pattern by arranging magnitude values of load currents of a target power system, and a loss factor of a first reference pattern among first to third reference patterns Calculating a relative position of the target load pattern on the basis of; and applying the target load pattern to any one of the reference patterns according to the calculated relative position to calculate the characteristic coefficient, and applying the calculated characteristic coefficient to the loss coefficient of the reference pattern It relates to a method of calculating the loss factor of a power system comprising the step of calculating the loss factor of the target power system.

Loss factor

Description

Calculation method of loss factor of power system using load pattern {POWER SYSTEM LOSS FACTOR CALCULATION METHOD USING LOAD PATTERN}

The present invention relates to a method for calculating a loss factor of a power system using a load pattern.

In general, power is delivered to consumers through the process of power generation, distribution and faucet. At this time, power loss occurs in each stage during power generation, distribution and reception.

In addition, power loss occurs in power equipment such as transformers and shunts.

At this time, the power loss is calculated by multiplying the square of the load resistance and the internal resistance of the power line or power equipment. However, the load current flowing to the power plant fluctuates in real time, so an error occurs when calculating the power loss using the load current.

Conventionally, the maximum load current displayed during the calculation period is used instead of the instantaneous value of the load current when calculating the loss of the actual power system, and this value is approximated with the power loss actually generated. There is a problem of reliability.

In particular, although the loss coefficient was calculated using the Wolf's equation in the related art, there is a problem that the accuracy is low due to a large error from the measured value.

It is an object of the present invention to provide a method for calculating the loss factor of grid power using a reference pattern.

According to the present invention, a method for calculating a loss factor of a power system, the method comprising: (a) calculating a target load pattern by aligning magnitude values of load currents of a target power system; (b) calculating a relative position of the target load pattern based on a loss factor of the first reference pattern among the first to third reference patterns; And (c) calculating the characteristic coefficient by applying the target load pattern to any one of the reference patterns according to the calculated relative position, and applying the calculated characteristic coefficient to the loss coefficient of the reference pattern. A method of calculating a loss factor of a power system may be provided, comprising calculating a loss factor of.

In addition, the present invention has a merit that the measured value and the error are small by using the reference pattern, the relative position and the characteristic coefficient in the power system.

In addition, there is an advantage that the error between the measured value and the calculated value can be reduced by correcting the characteristic coefficient by applying the load ratio.

The present invention has the advantage of operating a reasonable and economical power system by accurately calculating the power loss generated in the power system.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. In the following description of the present invention, if it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

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.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described in the specification, and one or more other It is to be understood that the present invention does not exclude the possibility of the presence or the addition of features, numbers, steps, operations, components, parts, or a combination thereof.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In order to facilitate a thorough understanding of the present invention, the same reference numerals are used for the same means regardless of the number of the drawings.

1 is a flowchart illustrating a method of calculating a loss factor of a power system according to an embodiment of the present invention.

Referring to FIG. 1, generating a target load pattern by arranging load currents of a target system based on a magnitude value of the load current (S100), based on a loss factor of a first reference pattern among first to third reference patterns. Computing the relative position of the target load pattern (S200) and applying the target load pattern to any one of the reference pattern according to the calculated relative position to calculate the characteristic coefficient, and apply the calculated characteristic coefficient to the loss coefficient of the reference pattern Computing the loss coefficient of the target power system (S300).

Specifically, in the step S100 of generating a target load pattern by arranging the load current of the target system according to the magnitude value of the load current, receiving the real-time load current of the target system and arranging in order of the magnitude value of the load current. At this time, the magnitude value of the load current is sorted in descending order.

For example, the Jangnam D / L work load curve shown in FIG. 2 is arranged according to the magnitude value of the load current as in FIG. 3 to generate a target load pattern.

Next, the step (S200) of calculating the relative position of the target load pattern based on the loss factor of the first reference pattern among the first to third reference patterns, first, the first to third shown in FIGS. Compare the reference pattern with the target load pattern.

FIG. 4 is a diagram illustrating a first reference pattern, in which a load current decreases linearly, and FIG. 5 is a diagram illustrating a second reference pattern, in which a load current decreases logarithmically. The figure which shows a 3rd reference pattern shows that load current decreases exponentially.

In this case, the loss coefficient of the reference pattern (H _a) of Figure 4 may be represented as shown in equation (1).

[Equation 1]

The loss coefficient H _b of the second reference pattern of FIG. 5 is expressed by Equation 2 below.

[Equation 2]

6 is a pattern in which the load current of the power system decreases exponentially.

Here, the loss coefficient H _c of the third reference pattern of the pattern illustrated in FIG. 3 is expressed by Equation 3 below.

&Quot; (3) "

은 최대 부하전류(I_max)를 최소부하전류(I_min)으로 나눈 값을 나타낸다.here,

Denotes the value obtained by dividing the maximum load current I _max by the minimum load current I _min .

Here, the reason why 1/3 in each of the equations (1) to (3) is to take the average of the values in the parentheses.

In this case, the target load pattern is generated similarly to any one of the first to third reference patterns illustrated in FIGS. 4 to 6. Next, the relative position of the target load pattern is calculated based on the first reference pattern.

The relative position P may be calculated as shown in Equation 4.

&Quot; (4) "

The relative position P of the target power system may be expressed as a relationship between the maximum (I _max ), the minimum (I _min ), the middle (I _mid ), and the average load current (I _avr ) of the power system as shown in Equation 4. .

At this time, the pattern relative position P becomes zero when the average load current I _avr and the intermediate load current I _mid of the power system are the same. In this case, the relative position P, which is the first reference pattern and is spaced apart in the direction of the second reference pattern or the third reference pattern around the first reference pattern, is used for the calculation of the loss factor H.

Calculating a characteristic coefficient by applying the target load pattern to any one of the reference patterns according to the calculated relative position, and calculating the loss coefficient of the target power system by applying the calculated characteristic coefficient to the loss coefficient of the reference pattern (S300). First, the characteristic coefficient is calculated by applying a value obtained by calculating a relative position based on a loss coefficient of one of the first to third reference patterns. Next, the loss coefficient H of the target system is calculated using the characteristic coefficient.

For example, when the target load pattern is in the third reference pattern direction based on the first reference pattern, the characteristic coefficient K is calculated using the loss factor of the first reference pattern.

를 나타낸다.FIG. 7 is a graph showing the correlation of loss coefficients of the first to third reference patterns.

Indicates.

일 때, 상대 위치(P)는 A/B의 위치에 있을 경우 대상 계통의 손실 계수 H는 H_c와 가까운 값을 가진다. Referring to Figure 7,

When the relative position P is at the position A / B, the loss factor H of the target system has a value close to H _c .

Here, the characteristic coefficient K is calculated as shown in equation (5).

[Equation 5]

At this time, the loss factor (H) of the target system is calculated by a value separated from Ha by a predetermined distance in the Hc direction, that is, Equation (6).

&Quot; (6) "

On the other hand, when the relative position is biased in the direction of the second reference pattern with respect to the first reference pattern, the characteristic coefficient K is calculated as in Equation (7).

[Equation 7]

Here, Equation 7 is a case where the average load current is smaller than the intermediate load current, and the relative position is a negative value.

The loss factor H of the target system at this time may be calculated as shown in Equation 8.

[Equation 8]

Table 1 shows the results calculated using data measured for one month in Kyonam D / L of KEPCO distribution system.

TABLE 1

circuit I _max I _min I _avr Jiaonan D / L 226.9 90.8 156.7

When the relative position of the target load pattern is obtained by using Equation 4, first, the load current intermediate value I _mid must be calculated. At this time, the load current intermediate value I _mid is 158.9A since it is the intermediate value between the maximum load current I _max and the minimum load current I _min .

When the relative position is calculated using Equation 4, it is -0.0314.

를 계산하면, 최소 부하 전류(I_min)을 최대 부하 전류(I_max)로 나눈 값이므로 0.4이다.And

When calculated, the minimum load current I _min divided by the maximum load current I _max is 0.4.

In this case, since the relative position P is negative, when the value is substituted into Equation 6, the loss factor H of the target load pattern may be 0.5037.

Table 2 is a table comparing the loss coefficient calculated by using the present invention with the loss coefficient calculated by the conventional method as data measured for one month in Kyonam D / L of KEPCO distribution system.

TABLE 2

Item Conventional method Example Actual value Calculation result 0.54527 0.50366 0.50498 error 0.04029 0.00132

As shown in Table 2, the loss coefficient according to the conventional method has an error of 0.04029 from the actual value, and the error between the loss coefficient and the actual value according to the present invention is 0.00132. Therefore, it can be seen that the error coefficient calculation according to the present invention has fewer errors than the prior art.

In addition, the present invention when the mean load current (I _avr) of the middle load current (I _mid) are to calculate the loss factor (H) of the target load pattern through the loss coefficient of the reference pattern (H _a).

On the other hand, the present invention can calculate a more accurate loss factor (H) by correcting the characteristic coefficient (K).

을 이용하여 계산할 수 있다.For example, the corrected characteristic coefficient K _c is equal to the load factor F

Can be calculated using.

The corrected characteristic coefficient K _c is expressed by Equation 9 below.

[Equation 9]

The load factor F is the average power divided by the maximum power or the average load current I _avr divided by the maximum load current I _max .

가 적용되어 특성 계수로 인한 오차를 보정할 수 있다.Accordingly, the load factor F and

Can be applied to correct the error due to the characteristic coefficient.

The loss coefficients are calculated by applying the error-corrected characteristic coefficients to Equations 10 and 11.

[Equation 10]

[Equation 11]

Equation 10 is a loss factor H when the relative position P is greater than zero, and Equation 11 is a loss factor H when the relative position P is smaller than zero.

Table 3 is a comparison table comparing the loss factor calculated by the conventional method, the loss factor calculated by the present invention and the actual measured value for each line.

[Table 3]

Line name Loss factor (H) error Measured value Conventional technology Example Conventional technology Example Improving Jiaonan 0.504980 0.545267 0.502424 0.040287 0.002556 0.037731 Doosan 0.505278 0.529595 0.519520 0.024317 0.014242 0.010075 Dry 0.222170 0.199834 0.199203 0.22337 0.022967 -0.000631 Seoul Station 0.422370 0.428139 0.404305 0.005770 0.018065 -0.012295 Western insect 0.300478 0.306836 0.300335 0.006359 0.000143 0.006216 transport 0.311288 0.344737 0.315852 0.033449 0.004564 0.028885 Shilla 0.569120 0.621028 0.593097 0.051908 0.023977 0.027931 By newspaper 0.307505 0.331108 0.313797 0.023603 0.006292 0.017311 kidney 0.062366 0.091810 0.077354 0.029444 0.014989 0.014455 Ahyeon 0.473263 0.520798 0.42180 0.047535 0.001083 0.046453 Exercise 0.282203 0.244806 0.237504 0.037397 0.044699 -0.007302 Country of origin 0.269182 0.308540 0.287616 0.39358 0.018434 0.020924 Yulgok 0.502512 0.545498 0.509307 0.042987 0.006795 0.036191 Wrought iron 0.063599 0.096947 0.79526 0.034347 0.06927 0.017421

As shown in Table 3, the loss factor calculation method according to the present invention can obtain a loss factor with improved accuracy due to less error than the conventional method. Accordingly, the accuracy of power system loss calculations can be improved to enable the construction and operation of economical and reasonable systems.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It will be understood that the invention may be varied and varied without departing from the scope of the invention.

1 is a flowchart illustrating a method of calculating a loss factor of a power system according to an embodiment of the present invention.

Figure 2 shows the Yunnan D / L work load curve measured in chronological order.

3 is a graph in which the load curve shown in FIG. 2 is arranged in descending order of magnitude values of the load current.

4 to 6 are graphs showing first to third reference patterns, respectively.

7 is a graph showing the correlation of loss coefficients of the first to third reference patterns.

Claims (9)

In the method of calculating the loss factor of the power system, (a) calculating a target load pattern by arranging magnitude values of load currents of the target power system; (b) calculating a relative position of the target load pattern based on a loss factor of the first reference pattern among the first to third reference patterns; And (c) calculating the characteristic coefficient by applying the target load pattern to any one of the first to third reference patterns according to the calculated relative position, and applying the calculated characteristic coefficient to the loss coefficient of the first reference pattern. Calculating a loss factor of the target power system by applying, The first reference pattern is a pattern in which the magnitude value of the load current decreases linearly. The second reference pattern is a pattern in which the magnitude value of the load current decreases logarithmically. And wherein the third reference pattern is a pattern in which the magnitude value of the load current decreases exponentially. delete The method of claim 1, The loss factor (H _a ) of the first reference pattern is

Calculated by The loss coefficient H _b of the second reference pattern is

Calculated by The loss coefficient H _c of the third reference pattern is

Loss coefficient calculation method of the power system, characterized in that calculated by the equation. (here,

Is the minimum load current divided by the maximum load current) The method of claim 1, The relative position (P) is

Loss coefficient calculation method of the power system, characterized in that calculated by the equation. Where I _avr is the average value of the load current, I _mid is the middle value of the load current, I _max is the maximum value of the load current, and I _min is the minimum value of the load current. The method of claim 4, wherein The characteristic coefficient K is greater than zero when the relative position

Loss coefficient calculation method of the power system, characterized in that calculated by the equation. The method of claim 4, wherein The characteristic coefficient K is when the relative position is less than zero,

Loss coefficient calculation method of the power system, characterized in that calculated by the equation. The method according to any one of claims 1, 3 and 4, Step (c) is Compensation coefficients are calculated by applying the load factor of the target power system to the characteristic coefficients, and calculating the loss coefficients of the target power system by applying the calculated correction characteristic coefficients to the loss coefficients of the first to third reference patterns. Loss coefficient calculation method of the power system, characterized in that. The method of claim 7, wherein The correction characteristic coefficient (K _c ) is

Loss coefficient calculation method of the power system, characterized in that calculated by the equation. Where K is the characteristic factor and F is the load factor. The method of claim 1, And calculating a loss factor of the target power system using a loss factor of the first reference pattern when the target load pattern is a linearly decreasing pattern.

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