KR20210064732A - Apparatus and method for calculating local area governor free contribution - Google Patents

Abstract

Disclosed are a regional frequency tracking contribution level calculating device and a method thereof. According to the present invention, the regional frequency tracking contribution level calculating device comprises: a phasor measurement machine for acquiring a bus frequency and electrical output data of each generator; a grid frequency calculating unit for calculating a grid frequency from the bus frequency; a mechanical input estimating unit for estimating a regional mechanical input from the grid frequency and the electrical output data; an acceleration energy calculation unit for calculating a regional acceleration force and regional acceleration energy from the deviation of mechanical input and electrical output; and a contribution level detection unit that detects a contribution level to frequency tracking based on a change amount of the grid frequency and the regional acceleration energy.

Description

Apparatus and method for frequency tracking contribution by region {APPARATUS AND METHOD FOR CALCULATING LOCAL AREA GOVERNOR FREE CONTRIBUTION}

The present invention relates to an apparatus and method for calculating regional frequency tracking contribution, and more particularly, calculating the regional frequency tracking contribution from the bus frequency and electrical output data of the generator acquired through a phasor measuring device for a power system in which multiple generators are operating. It relates to an apparatus and method for calculating the frequency tracking contribution by region.

According to the electricity market operation rules, to maintain the frequency of the system within the maintenance range, it is necessary to secure a frequency adjustment reserve of 1,500MW or more.

Frequency adjustment reserve is divided into frequency maintenance reserve and frequency recovery reserve. Frequency maintenance reserve power is the reserve power input to the primary frequency response, and it is based on the frequency following operation (Governor Free, frequency following) response of the generator.

In order to secure reserve power, the operation power generation plan is established by applying the power generation constraint which sets the upper limit of the reference output to 95% of the bid supply capacity for most generators.

There is a provision for coal-fired power generators to set the upper limit of the standard output at 95% to 100% so that the reserve power can be secured first by generators other than coal-fired power plants, and for nuclear power generators, there is a provision to fix the output at 100% of the available bid supply capacity. . However, there is currently no provision on the criteria for selecting generators that should have reserve power in priority.

The background technology of the present invention is disclosed in 'Reserve Force Operation Variable Control Device' of Korean Patent Application Laid-Open No. 10-2014-0091951 (2014.07.23).

The present invention was devised to improve the above problems, and an object according to an aspect of the present invention is to track the frequency of each region from the bus frequency and the electrical output data of the generator acquired through the phasor measuring device for the power system in which several generators are operating. It is to provide an apparatus and method for calculating the contribution of frequency tracking by region for calculating the contribution.

According to an aspect of the present invention, there is provided a phasor meter for obtaining a bus frequency and electrical output of each generator; a grid frequency calculator for calculating a grid frequency from the bus frequency; a mechanical input estimator for estimating a regional mechanical input from the system frequency and electrical output; an acceleration energy calculation unit for calculating regional acceleration force and regional acceleration energy from the deviation of the mechanical input and the electrical output; and a contribution detection unit configured to detect a contribution to frequency tracking based on the change amount of the system frequency and the regional acceleration energy.

The grid frequency calculation unit of the present invention is characterized in that it calculates the grid frequency from the bus frequency and the capacity of the generator.

The contribution detection unit of the present invention is characterized in that it detects the contribution to the frequency tracking using a Kalman filter algorithm.

The Kalman filter algorithm of the present invention is characterized in that it is generated by the amount of change in the system frequency and the acceleration energy for each region.

The acceleration energy calculation unit of the present invention calculates the regional acceleration force from the deviation of the mechanical input and the electrical output, and calculates the regional acceleration energy by accumulating the regional acceleration force.

The contribution detection unit of the present invention comprises: a Kalman filter algorithm generator for generating a Kalman filter algorithm using the change amount of the system frequency and the regional acceleration energy; and a contribution calculation unit for calculating a contribution to the frequency tracking for each region from the Kalman filter algorithm.

The Kalman filter algorithm generator of the present invention determines and normalizes the length of data to be used in the Kalman filter algorithm.

In accordance with an aspect of the present invention, there is provided a method for calculating regional frequency tracking contribution, comprising: acquiring, by a phasor measuring device, a bus frequency and an electrical output of each generator; calculating, by a grid frequency calculator, a grid frequency from the bus frequency; estimating, by a mechanical input estimator, a regional mechanical input from the system frequency and electrical output; calculating, by an acceleration energy calculator, an acceleration force for each region and an acceleration energy for each region from the deviation between the mechanical input and the electrical output; and detecting, by a contribution detection unit, a contribution to frequency tracking based on the amount of change in the system frequency and the acceleration energy for each region.

In the step of calculating the grid frequency of the present invention, the grid frequency calculator calculates the grid frequency from the bus frequency and the capacity of the generator.

In the step of detecting the contribution of the present invention, the contribution detecting unit is characterized in that it detects the contribution to the frequency tracking using a Kalman filter algorithm.

The Kalman filter algorithm of the present invention is characterized in that the system frequency change amount and the region acceleration energy data is generated.

In the step of calculating the regional acceleration force and regional acceleration energy of the present invention, the acceleration energy calculation unit calculates the regional acceleration force from the deviation of the mechanical input and the electrical output, and calculates the regional acceleration energy by accumulating the regional acceleration force characterized in that

The step of detecting the contribution of the present invention may include: generating, by a Kalman filter algorithm generating unit, a Kalman filter algorithm using the change amount of the system frequency and the acceleration energy for each region; and a contribution calculation unit calculating a contribution to the frequency tracking for each region from the Kalman filter algorithm.

In the generating of the Kalman filter algorithm of the present invention, the Kalman filter algorithm generator determines and normalizes the length of data to be used in the Kalman filter algorithm.

An apparatus and method for calculating regional frequency tracking contribution according to an aspect of the present invention improve the efficiency of a phasor measuring instrument capable of measuring the dynamic power generation characteristics of a power system, and reflect this to evaluate regional contribution to frequency tracking operation of a generator do.

An apparatus and method for calculating regional frequency tracking contribution according to another aspect of the present invention improves frequency stability in the event of an accident by planning a power generation source configuration based on regional frequency tracking contribution.

According to another aspect of the present invention, an apparatus and method for calculating regional frequency tracking base strength plan frequency adjustment reserve power based on regional frequency tracking contribution, so that it is possible to reduce the amount of reserve and reduce the purchase cost of the reserve.

1 is a block diagram of an apparatus for calculating regional frequency tracking contribution according to an embodiment of the present invention.
2 is a flowchart of a method for calculating regional frequency-following airways according to an embodiment of the present invention.
3 is a schematic diagram of a Kalman filter algorithm according to an embodiment of the present invention.
4 is a flowchart of a Kalman filter algorithm according to an embodiment of the present invention.
5 is a diagram illustrating an example of satisfying a fluctuation equation of frequency data according to an embodiment of the present invention.
6 is a diagram illustrating an example of normalizing data of a measurement vector over time according to an embodiment of the present invention.
7 is a diagram illustrating data according to time of an output matrix according to an embodiment of the present invention.
8 is a diagram illustrating a result of calculating a frequency tracking contribution by region according to an embodiment of the present invention.
9 is a diagram illustrating a system frequency when an amount of response by region is increased according to an embodiment of the present invention.
10 is a diagram illustrating a system frequency (expansion) when the response amount by region increases according to an embodiment of the present invention.
11 is a diagram illustrating a system frequency change when an accident occurs for each case.

Hereinafter, an apparatus and method for calculating regional frequency tracking contribution according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In this process, the thickness of the lines or the size of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, the terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to intentions or customs of users and operators. Therefore, definitions of these terms should be made based on the content throughout this specification.

Implementations described herein may be implemented in, for example, a method or process, an apparatus, a software program, a data stream, or a signal. Although discussed only in the context of a single form of implementation (eg, only as a method), implementations of the discussed features may also be implemented in other forms (eg, in an apparatus or a program). The apparatus may be implemented in suitable hardware, software and firmware, and the like. A method may be implemented in an apparatus such as, for example, a processor, which generally refers to a processing device, including a computer, microprocessor, integrated circuit or programmable logic device, or the like. Processors also include communication devices such as computers, cell phones, portable/personal digital assistants (“PDAs”) and other devices that facilitate communication of information between end-users.

1 is a block diagram of an apparatus for calculating regional frequency tracking contribution according to an embodiment of the present invention.

Referring to FIG. 1 , an apparatus for calculating regional frequency tracking contribution according to an embodiment of the present invention includes a phasor measuring device 10 , a system frequency calculation unit 20 , a mechanical input estimation unit 30 , and an acceleration energy calculation unit 40 . , and a contribution detection unit 50 .

The phasor meter 10 acquires the bus frequency and electrical output data of each generator.

The system frequency calculation unit 20 calculates a system frequency that can represent the system premise from the frequencies of each generator obtained by the phasor measuring device 10 .

The mechanical input estimator 30 estimates the regional mechanical input from the grid frequency calculated by the grid frequency calculator 20 and the electrical output data.

The acceleration energy calculation unit 40 calculates regional acceleration force and regional acceleration energy from the deviation between the mechanical input and the electrical output estimated by the mechanical input estimation unit 30 .

The contribution detection unit 50 detects the contribution to the frequency tracking by using the Kalman filter algorithm. The contribution detecting unit 50 includes a Kalman filter algorithm generating unit 51 and a contribution calculating unit 52 .

The Kalman filter algorithm generating unit 51 generates a Kalman filter algorithm by using the system frequency change amount and regional acceleration energy data based on the fluctuation equation.

The contribution calculation unit 52 calculates the contribution to frequency tracking by using the Kalman filter algorithm generated by the Kalman filter algorithm generation unit 51 .

Hereinafter, a method of calculating the frequency tracking contribution by region according to an embodiment of the present invention will be described in detail with reference to FIGS. 2 to 4 .

2 is a flowchart of a method for calculating regional frequency tracking airways according to an embodiment of the present invention, FIG. 3 is a schematic diagram of a Kalman filter algorithm according to an embodiment of the present invention, and FIG. 4 is a Kalman filter according to an embodiment of the present invention. A flowchart of the filter algorithm.

First, the phasor meter 10 acquires the bus frequency and electrical output data of each generator (S10).

Then, the system frequency calculation unit 20 calculates a system frequency that can represent the system premise from the frequencies of each generator obtained by the phasor measuring device 10 (S20).

The mechanical input estimator 30 estimates the regional mechanical input from the grid frequency calculated by the grid frequency calculator 20 and the electrical output data (S30). Since the mechanical input of the generator cannot be measured by the phasor measuring device 10 , the mechanical input can be estimated from the frequency and electrical output data acquired by the phasor measuring device 10 .

The acceleration energy calculation unit calculates regional acceleration force and regional acceleration energy from the deviation of the mechanical input and electrical output estimated by the mechanical input estimation unit 30 ( S40 ).

[rad],

[rad/sec], 기계적 입력과 전기적 출력을 각각

,

, 정규화된 관성정수를

[MJ/MVA]라 하면, 동요방정식은 수학식 1과 같다.The transient stability of a synchronous generator can be analyzed through the swing equation. The phase angle and angular velocity of the rotor are respectively

[rad],

[rad/sec], mechanical input and electrical output respectively

,

, the normalized constant of inertia

Speaking of [MJ/MVA], the fluctuation equation is the same as Equation 1.

,

라고 하면, 둘 사이의 관계는 수학식 2와 같다.The reference angular velocity of the rotor and the reference frequency of the system are respectively

,

, the relationship between the two is the same as in Equation 2.

가 변화하면 기계적 입력

과

의 편차에 따라 발전기 회전자의 회전이 가속 또는 감속한다. 따라서 기계적 입력

과 전기적 출력

의 편차를 가속력(또는 감속력)

로 정의하면, 가속력(또는 감속력)

는 수학식 3과 같이 표현된다. Electrical output by disturbance in the fluctuation equation

changes in mechanical input

and

The rotation of the generator rotor accelerates or decelerates according to the deviation of Therefore, mechanical input

and electrical output

The deviation of the acceleration force (or deceleration force)

If defined as , acceleration force (or deceleration force)

is expressed as Equation (3).

라고 하면, 시간

초부터

초까지 누적되는 가속(감속)에너지는 수학식 4와 같다.If the acceleration force is integrated with respect to time, it becomes an expression for the acceleration (deceleration) energy for the generator. acceleration (deceleration) energy

If you say, time

from the beginning

Acceleration (deceleration) energy accumulated up to seconds is expressed in Equation (4).

Next, the Kalman filter algorithm generating unit 51 generates a Kalman filter algorithm using the system frequency change amount and regional acceleration energy data based on the fluctuation equation (S50).

초까지의 주파수 변화량과 발전기의 가속에너지는 수학식 5와 같이 표현할 수 있다.When both sides of the fluctuation equation of Equation 1 are integrated, the relationship between the frequency change amount and the acceleration energy appears, from 0 second

The frequency change amount up to the second and the acceleration energy of the generator can be expressed as Equation 5.

When the power system is divided into a total of N regions, the contribution of regional frequency tracking is calculated between the amount of system frequency change and regional acceleration energy based on Equation 5.

Since the mechanical input of the generator cannot be measured by the phasor measuring device 10 , the mechanical input must be estimated from the frequency and power output data acquired by the phasor measuring device 10 , and the acceleration energy must be calculated using this.

,

라고 한다. 계통 주파수 변화량을

라고 하고, 지역별 추정 가속에너지를

, 지역별 주파수추종 기여도를

로 정의한다. 여기서

는 N개의 지역 중

번째 지역의 데이터를 의미한다. The estimated mechanical input and the estimated acceleration energy calculated using it

,

It is said system frequency change

, and the estimated acceleration energy for each region is

, the frequency tracking contribution by region

is defined as here

is among the N regions.

It means the data of the second region.

를 산출하는 것을 목표로 하며, 이를 표현하면 수학식 6과 같다. 도 3은 칼만 필터 알고리즘의 개요도이다. The Kalman filter algorithm shows the contribution of regional frequency tracking between the frequency change amount and regional acceleration energy.

It aims to calculate , which is expressed as Equation (6). 3 is a schematic diagram of the Kalman filter algorithm.

Equation 6 is a relational expression between the frequency change amount and the acceleration energy. Based on Equation 6, a system model of the Kalman filter algorithm can be constructed.

The Kalman filter algorithm estimates state variables from measured data over time based on a state space system model composed of state variables and measured data.

The state space system model consists of a state equation and a measurement equation, and is composed of a form including measurement noise and system noise.

When the state space system model is composed of N state variables and m measurement data, the state space system model expression at a specific time k is as shown in Equations 7 to 10.

In this case, the state space system model components are shown in Table 1.

Mark size name

N×1 state variable vector

m×1 output vector

m×1 measurement vector

N×N state matrix

m×N output matrix

N×1 system noise

N×N System Noise Covariance

m×1 measurement noise

m×m Measurement noise covariance

라고 정의할 때 수학식 7은 시간에 따른 상태변수의 변화를 나타내는 상태 방정식으로, 여기서

는 이전 상태에 기반한 상태전이 행렬이고,

는 시스템 잡음이다.the state variable vector at a specific time k

Equation 7 is a state equation representing the change of the state variable with time, where

is a state transition matrix based on the previous state,

is the system noise.

를 갖는 정규분포 잡음 변수로 시스템 모델과 실제 시스템의 차이에서 발생하는 부정확성, 시스템 자체의 잡음 등을 포함한다.System noise is mean 0, covariance matrix

As a normally distributed noise variable with , it includes inaccuracies caused by the difference between the system model and the actual system, and the noise of the system itself.

와 시스템의 출력 벡터

, 그리고 그 출력을 측정한 측정 벡터

의 관계를 나타낸 식이다. 여기서

는 상태변수 벡터와 시스템의 출력에 관계되는 출력 행렬이고,

는 측정 잡음으로, 평균 0, 공분산행렬

을 갖는 정규분포 잡음 변수이다.Equations 8 and 9 are state variable vectors

and the output vector of the system

, and the measurement vector measuring its output

is an expression expressing the relationship between here

is the output matrix related to the state variable vector and the output of the system,

is the measurement noise, mean 0, covariance matrix

It is a normally distributed noise variable with .

The estimation process of the Kalman filter algorithm at a specific time k is as shown in FIG. 4 and can be largely divided into a prediction step and a correction step.

In the prediction step, the predicted state variable at the current time k is calculated with respect to the state variable estimated at the previous time k-1, and this step is performed a priori.

In the correction step, the error is inductively corrected by using the error between the predicted value and the actual measured value in the prediction step.

The superscript - means that the value is a value calculated in the prediction step. The estimated value of the state variable vector is denoted by ^, and the error from the actual state variable is denoted by ~.

The state variable errors in the prediction step and the correction step are the same as in Equations 11 and 12, respectively, the error covariance means the covariance of the state variable error, and the error covariance in the prediction step and the calibration step is as shown in Equations 13 and 14.

The mean square error (MSE) of the state variable vector in the prediction step and the calibration step is expressed by Equations 15 and 16.

Here, tr means the diagonal trace of the matrix, and the mean square error of the state variable vector is the same as the diagonal sum of the error covariance matrix.

The Kalman filter algorithm performs estimation according to a calculation formula derived for the purpose of minimizing the mean square error of the estimated value of the state variable vector in the prediction step and the calibration step, respectively.

The prediction step consists of a priori state variable prediction and prediction error covariance calculation.

로부터 현재 시간 k의 상태변수 벡터 예측 값

을 계산한다.The a priori state variable prediction is as Equation 17, and the state variable vector estimated value estimated at the previous time k-1

state variable vector predicted value at current time k from

to calculate

For this, the error covariance of the predicted value of the state variable vector can be calculated as in Equation (18).

The correction step consists of calculating the prediction error of the measured data, calculating the optimal Kalman gain, correcting the inductive state variable, and calculating the correction error covariance.

는 수학식 (19)와 같이 계산된다.Prediction error of measurement data

is calculated as in Equation (19).

는 측정데이터의 예측 오차에 의한 보정의 가중치를 의미하며 수학식 20과 같이 계산된다.Optimal Kalman Gain

denotes a weight of correction due to the prediction error of the measurement data and is calculated as in Equation 20.

에 측정데이터의 예측 오차를 이용한 보정을 수행하여 최종 추정 값

를 구하는 방식으로 이루어지며, 수학식 21과 같이 계산된다.Inductive state variable correction is a state variable vector predicted value

The final estimated value by performing correction using the prediction error of the measured data

, and is calculated as in Equation 21.

에 대한 오차 공분산

는 수학식 22와 같이 계산되며, 그 값은 시간 k+1에서의 예측단계에서 사용된다.Corrected final state variable vector estimate

error covariance for

is calculated as in Equation 22, and its value is used in the prediction step at time k+1.

Next, the contribution calculation unit 52 calculates the contribution to the frequency tracking by using the Kalman filter algorithm generated by the Kalman filter algorithm generation unit 51 ( 60 ).

An example of applying the regional frequency tracking contribution calculation method proposed for the domestic nationwide system will be described.

5 is a diagram showing an example of satisfying the fluctuation equation of frequency data according to an embodiment of the present invention, and FIG. 6 is a diagram showing an example of normalizing data of a measurement vector over time according to an embodiment of the present invention, 7 is a diagram illustrating data over time of an output matrix according to an embodiment of the present invention, FIG. 8 is a diagram illustrating a frequency tracking contribution calculation result by region according to an embodiment of the present invention, and FIG. 9 is a diagram illustrating the present invention It is a diagram showing the system frequency when the response amount by region increases according to an embodiment of the present invention, FIG. 10 is a diagram showing the system frequency (enlarged) when the response amount by region increases according to an embodiment of the present invention, and FIG. 11 is a case-specific accident It is a diagram showing the system frequency change when it occurs.

The domestic system was divided into six regions: Seoul/Gyeonggi, Incheon, Gangwon, Chungcheong, Jeolla, and Gyeongsang. When the Shin-Kori #3 generator (1,400MW) dropped out in 10 seconds in the domestic power system, the data required for the Kalman filter algorithm was obtained.

와 지역별 추정 가속에너지 데이터가 필요하다. To construct the Kalman filter algorithm based on Equation 6, the amount of systematic frequency change

and estimated acceleration energy data for each region are required.

The frequency acquired by the phasor measuring instrument 10 has a different value for each bus according to the system configuration. Therefore, the frequency measured from a single bus does not satisfy the perturbation equation for the mechanical input and electrical output of the whole system.

)란 전체 전력계통을 대표할 수 있는 주파수를 의미한다.When constructing the Kalman filter algorithm, one representative frequency data is required. For this purpose, the grid frequency can be used. grid frequency (

) means a frequency that can represent the entire power system.

번째 지역 최대 용량 발전기 모선에서 측정한 주파수 데이터를

[Hz],

번째 지역 최대 용량 발전기의 용량를

[MVA]라고 하면, 계통 주파수를 수학식 23과 같이 계산할 수 있다.Calculate the grid frequency by measuring the frequency of the maximum capacity generator bus in each region.

Frequency data measured from the largest capacity generator bus in the second area

[Hz],

The capacity of the second regional maximum capacity generator

Referring to [MVA], the system frequency can be calculated as in Equation 23.

At this time, the frequency measurement generator bus by region and the corresponding generator capacity are shown in Table 2.

area generator

[MVA]

[MVA] Seoul/Gyeonggi Wirye Cogeneration #1 476 Incheon Yeongheung #5 1,046 Gangwon Samcheok #1 1,230 Chungcheong Taean #9 1,254 Jeolla Hanbit #1 1,284 minor Hanul #4 1,220

Figure 5 (a) is a comparison of the frequency measured in Samcheonpo #1 generator bus and the total mechanical input and electrical output of the national generator, (b) is a comparison of the grid frequency and the total mechanical input and electrical output of the national generator . According to the fluctuation equation of Equation 1, when the rate of change of the frequency is 0, the values of the mechanical input and the electrical output should be the same.

It can be seen that the frequency measured from a single bus in (a) of FIG. 5 does not satisfy the fluctuation equation, whereas the system frequency in (b) satisfies the fluctuation equation.

Since the mechanical input of the generator cannot be measured by the phasor measuring device 10 , the mechanical input can be calculated from the frequency and power output data acquired by the phasor measuring device 10 . From the fluctuation equation, the regional mechanical input can be calculated as in Equation 24.

는 지역

의 평균 관성정수[MJ/MW]이며 수학식 25와 같이 계산된다. 여기서

는 지역

에 속하는 발전기의 번호이며,

는

발전기의 용량[MVA]이고

는

발전기의 관성정수[MJ/MW]이다.here

is the area

is the average inertia constant of [MJ/MW] and is calculated as in Equation 25. here

is the area

is the number of generators belonging to

is

is the capacity of the generator [MVA]

is

It is the inertia constant of the generator [MJ/MW].

Since the calculated mechanical input includes the noise generated in the process of calculating the rate of change of the system frequency, the Kalman filter can be applied to remove the noise. The system model of the Kalman filter algorithm for this is shown in Equations 26 and 27.

을 이용하여 지역별 추정 가속력, 추정 가속에너지를 수학식 28과 같이 계산할 수 있고, 이를 각각

,

라고 한다.Estimated mechanical input by region

Estimated acceleration force and estimated acceleration energy for each region can be calculated as in Equation 28 using

,

It is said

When the regional frequency tracking contribution can be expressed as in Equation 6, the Kalman filter algorithm system model for estimating it is as Equations 29 and 30.

는 지역별 주파수추종 기여도

로 구성된다. 전국계통을 6개 지역으로 구분하였으므로 상태변수 벡터는 6×1 행렬이다.State variable vector to be estimated

is the regional frequency tracking contribution

is composed of Since the national system is divided into 6 regions, the state variable vector is a 6×1 matrix.

는 6×6 행렬로, 시간에 따른 상태변수 벡터의 변화를 표현하며, 이를 단위행렬로 설정하여 주파수추종 기여도의 예측에 있어 시간에 따른 변화가 없다고 가정한다.state matrix

is a 6×6 matrix, which expresses the change of the state variable vector with time, and sets it as an identity matrix to assume that there is no change with time in the prediction of the frequency-following contribution.

은 6×1 행렬로,

는 지역별 주파수추종 기여도

에 대한 잡음으로 지역별 주파수추종 기여도의 예측 단계에 작용한다. 시스템 잡음의 공분산 행렬

는 6×6 행렬로, 수학식 31과 같이 파라미터

를 대각 성분으로 갖는다.system noise

is a 6×1 matrix,

is the regional frequency tracking contribution

It acts on the prediction stage of the frequency tracking contribution by region as noise for . Covariance Matrix of System Noise

is a 6×6 matrix, and is a parameter as shown in Equation 31.

has as a diagonal component.

는 1×1 행렬로, 계통 주파수

의 변화량

이며 기준 주파수인 60Hz에서 벗어난 값을 의미한다. measurement vector

is a 1×1 matrix, where the system frequency

change in

and means a value out of the reference frequency of 60Hz.

의 시간에 따른 데이터를 나타낸 것으로, 최종 값이 1이 되도록 정규화(Normalize)하였다.6 is a measurement vector

It shows the data according to time, and it was normalized so that the final value is 1.

는 1×6 행렬로, 수학식 6을 나타내는 행렬이다. 지역별 추정 가속에너지

와 지역별 주파수추종 기여도

를 통해 계통 주파수의 변화를 나타낸다.output matrix

is a 1×6 matrix, which is a matrix represented by Equation (6). Estimated Acceleration Energy by Region

and frequency tracking contribution by region

represents the change in the system frequency through

의 시간에 따른 데이터를 나타낸 것으로, 각각 같은 값으로 정규화하였다.7 is an output matrix

data over time, each normalized to the same value.

은 1×1 행렬이므로 측정 잡음의 공분산 행렬

또한 1×1 행렬로, 하나의 파라미터

을 갖는다.measurement noise

is a 1×1 matrix, so the covariance matrix of the measurement noise

Also a 1×1 matrix, one parameter

has

The Kalman filter algorithm is applied to the above data to estimate the regional frequency tracking contribution, and the estimation is repeatedly performed so that the value converges.

8 and Table 3 show the results of the convergence of regional frequency tracking contributions by repeating the estimation process 70 times for the data set and the regional rankings.

area Frequency tracking contribution ranking Seoul, Gyeonggi 0.4886 One Jeolla 0.2738 2 Chungcheong 0.150 3 Incheon 0.0421 4 Gangwon 00415 5 minor 0.0293 6

For the same accident, by adjusting the droop coefficient of the generator, the response amount was increased by 35 MW by region, and the rise of the lowest frequency was compared.

9 shows the change of the system frequency when the response amount of each region increases by 35 MW, and FIG. 10 is an enlarged view of this.

Table 4 shows the increase of the lowest point of the system frequency and the increase of the lowest point of the system frequency compared to the case where the response amount is not increased when the response amount is increased by 35MW by region.

Area of increase in response frequency trough
[Hz] Frequency Lowest Rise [Hz] ranking does not increase 59.9220 - - Seoul, Gyeonggi 59.9272 0.0052 One Jeolla 59.9262 0.0042 2 Chungcheong 59.9260 0.0040 3 Incheon 59.9258 0.0038 4 Gangwon 59.9257 0.0037 5 minor 59.9248 0.0024 6

Since the increased response amount (35MW) is small compared to the dropped generator capacity (1,400MW), the increase in the frequency lowest point is small, but there is a difference by region.

The same ranking was found when comparing the regional frequency tracking contribution ranking and the system frequency lowest point increase when the response amount increased by region.

Therefore, it is possible to evaluate the contribution to the system frequency recovery, especially the lowest frequency, by calculating the regional frequency tracking contribution through the proposed regional frequency tracking contribution calculation method in the event of an accident.

Meanwhile, according to the regional frequency tracking contribution rankings in Table 3, the Seoul and Gyeonggi regions have the highest frequency tracking contribution and the Gyeongsang region have the lowest frequency tracking contribution.

In order to check the effect of the frequency tracking contribution of the Seoul/Gyeonggi region and the Gyeongsang region on the frequency recovery, the cases showing the same frequency response by adjusting the droop coefficient of the generator in the region to increase the response amount were compared.

Case 1: Initial setting state

Case 2: Set to add 68.68MW of frequency tracking response in Seoul/Gyeonggi area

Case 3: Set to add 112.08MW of frequency tracking response in Gyeongsang area

For the three cases, the lowest frequency and the first recovery frequency are shown in FIG. 11 and Table 5.

Case 1 Case 2 Case 3

[Hz]

[Hz] 59.8492 59.8586
(+0.0094) 59.8587
(+0.0095)

[Hz] 59.9040 59.9099
(+0.0059) 59.9120
(+0.0080)

In Cases 2 and 3, since the frequency-following response was set to increase in the Seoul/Gyeonggi and Gyeongsang regions, respectively, it can be seen that both the lowest frequency and the primary recovery frequency increased compared to Case 1, which is the initial setting state.

In Cases 2 and 3, the frequency lowest point rose by 0.0094 Hz and 0.0095 Hz, respectively, showing almost the same rise.

In Case 2, the frequency tracking response in the Seoul and Gyeonggi regions increased by 68.68MW, and in Case 3, the frequency tracking response in the Gyeongsang region increased by 112.08MW.

Despite the difference in the additional frequency tracking response of 34.60MW, the frequency lowest point is the same, so it can be judged that the frequency tracking response in the Seoul and Gyeonggi regions has a greater contribution to frequency recovery than in the Gyeongsang region.

As described above, the apparatus and method for calculating the contribution of regional frequency tracking according to an embodiment of the present invention improve the efficiency of the phasor measurer 10 capable of measuring the power generation dynamic characteristics of the power system, and reflect this to drive the frequency tracking of the generator to evaluate the regional contribution to

In addition, the apparatus and method for calculating regional frequency tracking contribution according to an embodiment of the present invention plan the configuration of a power generation source based on regional frequency tracking contribution to improve frequency stability in case of an accident.

In addition, the apparatus and method for calculating the frequency following frequency by region according to an embodiment of the present invention makes it possible to reduce the amount of reserve and reduce the purchase cost of the reserve by planning the frequency adjustment reserve based on the contribution of frequency following by region.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary and those skilled in the art to which the art pertains can make various modifications and equivalent other embodiments therefrom. will understand Accordingly, the true technical protection scope of the present invention should be defined by the following claims.

10: phasor meter
20: system frequency calculation unit
30: mechanical input estimator
40: acceleration energy calculation unit
50: contribution detection unit
51: Kalman filter algorithm generating unit
52: contribution calculator

Claims (14)

a phasor meter that acquires the bus frequency and electrical output of each generator;
a grid frequency calculator for calculating a grid frequency from the bus frequency;
a mechanical input estimator for estimating a regional mechanical input from the system frequency and electrical output;
an acceleration energy calculation unit for calculating regional acceleration force and regional acceleration energy from the deviation of the mechanical input and the electrical output; and
and a contribution detection unit configured to detect a contribution to frequency tracking based on the change amount of the system frequency and the acceleration energy for each region. The method of claim 1, wherein the system frequency calculator
Frequency tracking contribution calculation device for each region, characterized in that calculating the grid frequency from the bus frequency and the capacity of the generator.
The method of claim 1, wherein the contribution detection unit
A frequency tracking contribution calculation device for each region, characterized in that the contribution to the frequency tracking is detected by using a Kalman filter algorithm. [4] The apparatus of claim 3, wherein the Kalman filter algorithm is generated from the change amount of the system frequency and the acceleration energy for each region. The method of claim 1, wherein the acceleration energy calculation unit
and calculating the regional acceleration force from the deviation of the mechanical input and the electrical output, and accumulating the regional acceleration force to calculate the regional acceleration energy. The method of claim 1, wherein the contribution detection unit
a Kalman filter algorithm generator for generating a Kalman filter algorithm by using the change amount of the system frequency and the regional acceleration energy; and
and a contribution calculation unit for calculating a contribution to the frequency tracking for each region from the Kalman filter algorithm. The apparatus of claim 6, wherein the Kalman filter algorithm generator determines and normalizes the length of data to be used in the Kalman filter algorithm. obtaining, by a phasor meter, a bus frequency and an electrical output of each generator;
calculating, by a grid frequency calculator, a grid frequency from the bus frequency;
estimating, by a mechanical input estimator, a regional mechanical input from the system frequency and electrical output;
calculating, by an acceleration energy calculator, an acceleration force for each region and an acceleration energy for each region from the deviation between the mechanical input and the electrical output; and
and detecting, by a contribution detection unit, a degree of contribution to frequency tracking based on the amount of change in the system frequency and the acceleration energy for each region. The method of claim 8, wherein in the step of calculating the grid frequency,
The grid frequency calculator calculates the grid frequency from the bus frequency and the capacity of the generator.
The method of claim 8, wherein in the step of detecting the contribution,
and the contribution detection unit detects the contribution to the frequency tracking by using a Kalman filter algorithm. 11. The method of claim 10, wherein the Kalman filter algorithm is
A method of calculating the contribution of frequency tracking by region, characterized in that it is generated from system frequency change amount and regional acceleration energy data. The method of claim 8, wherein in the step of calculating the regional acceleration force and the regional acceleration energy,
The acceleration energy calculation unit calculates the regional acceleration force from the deviation of the mechanical input and the electrical output, and accumulates the regional acceleration force to calculate the regional acceleration energy. The method of claim 8, wherein the detecting of the contribution
generating, by a Kalman filter algorithm generating unit, a Kalman filter algorithm by using the change amount of the system frequency and the acceleration energy for each region; and
A method for calculating the contribution to frequency tracking by region, characterized in that the contribution calculator calculates the contribution to the frequency tracking for each region from the Kalman filter algorithm. 14. The method of claim 13, wherein in generating the Kalman filter algorithm,
The Kalman filter algorithm generator determines the length of data to be used in the Kalman filter algorithm and normalizes the data length.

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