KR102020654B1 - Method and apparatus for providing transmission loss factor based on power system component modeling and big data processing - Google Patents

Abstract

Provided are a transmission loss coefficient providing method and an apparatus for performing the same. This method is a transmission loss coefficient providing method performed in a transmission loss coefficient providing apparatus operated by at least one processor, the step of extracting data for calculating the transmission loss coefficient from the input power system data, the extracted power system data Varying the effective power load by a minute unit load among a plurality of power generation buses included, and performing a power current calculation to supply the variable effective power load and the validity of the arbitrary power generation buses Calculating an amount of change in the effective power generation amount of the slack bus caused by the change of the power load, using the amount of change in the unit load effective power of the arbitrary generation bus and the amount of change in the effective power generation amount of the slack bus Calculating the transmission loss coefficient of the bus bar, and The total loss factor and a step for outputting via the user interface.

Description

METHOD AND APPARATUS FOR PROVIDING TRANSMISSION LOSS FACTOR BASED ON POWER SYSTEM COMPONENT MODELING AND BIG DATA PROCESSING}

The present invention relates to a power transmission loss coefficient providing method through power system component modeling and big data processing.

Recently, due to environmental problems such as global warming and difficulty in securing a location for transmission network construction, demands for eco-friendly, high-efficiency, distributed power sources adjacent to demand are expanding. The combined heat and power plant (hereinafter referred to as 'CHP'), which is one of the distributed power sources and has high energy use efficiency, is located adjacent to the demand site, resulting in geographical benefits. Such geographic benefits include minimizing social costs due to the construction of the grid, avoiding the construction of new high-voltage power transmission lines, increasing the energy efficiency of the country due to low transmission losses, and the benefits of operating the grid such as transmission congestion.

Although CHP has advantages not only in geographical benefits but also in terms of energy efficiency and system stability, its fair value has not been systematically evaluated.

In addition, as competition for power generation costs intensifies in the power market, the ranking of feeds is being pushed back despite the high transmission loss factor (TLF) of CHP. Accordingly, it is necessary to lay the foundation for establishing investment and management measures for CHP through mid / long-term projections of transmission loss coefficient (TLF).

The feeder ranking and revenue of the generator are affected by the transmission loss factor (TLF). The dictionary definition of the transmission loss factor (TLF) refers to the transmission loss rate occurring on the transmission line from the generator end to the meter installation position. The transmission loss factor (TLF) is the marginal loss factor (MLF) of the generator and refers to the amount of generation of the reference bus required to supply the unit load of arbitrary buses.

The value of the transmission loss coefficient (TLF) changes depending on the state of the power system. The power system is continuously changing due to generator entry and transmission network construction. Accordingly, the transmission loss coefficient (TLF) is also changing every year, but it is difficult for power generation companies to predict the value due to the lack of related software.

The transmission loss factor (TLF) was derived from the Penalty Factor (PF) of the transmission loss index. The penalty factor (PF) is derived from the economic problem of power supply, which minimizes the fuel costs of the generator while powering the load across the system (Allen J. Wood, Bruce F. Wollenberg, POWER GENERATION, OPERATION, AND CONTROL, JOHN WILEY & SONS INC., 1984, p. 114-116).

Disclosed is a transmission loss coefficient (TLF) calculation and management program for a conventional Korean energy management system (hereinafter, referred to as 'EMS'). However, these programs are calculated inside the EMS, and it is not possible to calculate the transmission loss factor (TLF) for the point-in-time calculation by the real-time calculation program.

An object of the present invention is to provide a method and apparatus for processing power system data provided by a power exchange and calculating and providing power current calculation and transmission loss coefficient through component modeling included in the power system data. will be.

According to one aspect of the invention, the transmission loss coefficient providing method is a transmission loss coefficient providing method performed in the transmission loss coefficient providing apparatus operated by at least one processor, which is required for calculating the transmission loss coefficient from the input power system data Extracting data, varying an effective power load by a minute unit load with respect to an arbitrary power generation bus among the plurality of power generation buses included in the extracted power system data, and performing a power current calculation to perform the variable active power load Calculating an amount of change in the effective power generation amount of the slack bus, which is required to supply the power generation and is generated due to the change in the effective power load of the arbitrary generation bus, the amount of change in the unit load effective power of the arbitrary generation bus and the slack bus Any of the above generation models using the change amount of the effective power generation amount Step of calculating the transmission loss factor, and a step for outputting via the user interface, the transmission loss factor.

The extracting may include receiving power flow data in an Institute of Electrical and Electronics Engineers (IEEE) format of PSS / E (Power System Simulator for Engineering), and extracting data necessary for calculating the transmission loss coefficient from the power flow data. Extracting and classifying the extracted data into bus data, branch data, and bus name data; and the varying step includes: classifying the classified data. Can be performed on a basic basis.

After the classifying, the method may further include converting the classified data into a text format.

Before the calculating, the method may further include modeling the component according to the PSS / E, and the calculating may include applying the modeling according to the PSS / E to perform the power current calculation.

In the modeling step, the switched shunt capacitor may be modeled as a fixed shunt capacitor having a fixed final capacitance data.

The modeling may include modeling a flexible AC transmission system (FACTS) facility as a load consuming only reactive power.

In the modeling, the 2 Winding Transformer may be modeled as two shunt capacitors and one line admittance for inputting power current data of the PSS / E.

In the modeling step, a 3 Winding Transformer modeled as 3 2 Winding Transformers may be modeled as an admittance using PSS / E power current data using a Star Point Bus which is a virtual bus.

In the modeling, the high voltage direct current (HVDC) may be modeled as a virtual load using power current data of the PSS / E as an input.

According to another feature of the invention, the transmission loss coefficient providing apparatus is an input unit for receiving power flow data of the Institute of Electrical and Electronics Engineers (IEEE) format of the PSS / E (Power System Simulator for Engineering), the power generation bus of the power system An output unit for outputting a power transmission loss coefficient of the screen, a memory for storing a program for calculating and outputting the power transmission loss coefficient based on the power flow data, and at least one processor for executing the program; After changing the effective power load by the unit load of any power generation bus among the plurality of power generation buses included in the power system data necessary for calculating the transmission loss coefficient filtered from the input power system data, the power current calculation is performed. Is required to supply the variable active power load and to the variable of the active power load. Calculates the amount of change in the effective power generation amount of the slack bus generated by using the change amount of the unit load effective power of the arbitrary power generation bus and the amount of change in the effective power generation amount of the slack bus, It includes instructions to calculate and output through the user interface.

The program classifies the data necessary for calculating the transmission loss coefficient into bus data, branch data, and bus name data, and converts the classified data into a text format and stores the data. It may include instructions to.

The power current calculation is performed based on component modeling according to PSS / E, and the component modeling includes a switched shunt capacitor and a fixed shunt capacitor modeled in an admittance form having a fixed capacitance. At least one of Fixed Shunt Capacitor), Flexible AC Transmission System (FACTS) facility modeled as a load consuming only reactive power, and High Voltage Direct Current (HVDC) modeled as a virtual load that takes power current data of PSS / E. It may include.

According to the embodiment of the present invention, it is possible to calculate the transmission loss coefficient (TLF) that affects the profit of the generator to enable the medium and long term projection of the transmission loss coefficient (TLF), and further, the basis of the investment and operation plan and the countermeasures of the generator. Can be formulated.

1 is a block diagram schematically showing the configuration of a transmission loss coefficient (TLF) providing apparatus according to an embodiment of the present invention.
FIG. 2 is a flowchart illustrating a method of operating a transmission loss coefficient (TLF) providing apparatus of FIG. 1.
3 illustrates a data extraction and classification process according to an embodiment of the present invention.
FIG. 4 is a view illustrating modeling of a fixed shunt capacitor and a switched shunt capacitor according to an embodiment of the present invention.
FIG. 5 is a diagram illustrating FACTS (Flexible AC Transmission System) facility modeling according to an embodiment of the present invention.
6 is a diagram illustrating high voltage direct current (HVDC) modeling according to an embodiment of the present invention.
7 and 8 are diagrams illustrating 2 Winding Transformer modeling according to an embodiment of the present invention.
9 is a diagram illustrating 3 Winding Transformer modeling according to an embodiment of the present invention.
10 is a block diagram showing a hardware configuration of a transmission loss coefficient (TLF) providing apparatus according to another embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise. In addition, the terms “… unit”, “… unit”, “… module” described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software. Can be.

In the present specification, the power system or system refers to electrical equipment physically interconnected, that is, power generation equipment, power transmission equipment, power distribution equipment, and other auxiliary equipment for supplying electricity generated by a power plant to an electric user.

Transmission Loss Factor (TLF) is the transmission loss factor of the generator. The transmission loss factor (TLF) is the marginal loss factor (MLF) of the transmission loss index. The transmission loss factor (TLF) is defined as the generation of the reference bus required to supply the unit load of any bus. Here, the bus refers to a common conductor to which transmission and distribution lines, generators, transformers, and ancestor facilities are connected.

Since the transmission loss coefficient (TLF) is the limit loss coefficient (MLF), it is represented by the inverse of the penalty coefficient (PF), and is defined as in Equation (1).

Here, TLF _i is a transmission loss coefficient of i generator or i bus (hereinafter, collectively referred to as i bus). PF _i is the penalty coefficient of the i bus. P _i is the active power output by the i bus. P _loss is the total loss power of the system (hereinafter referred to as 'loss'). There are a total of N busbars in the line (i = 1, ..., N).

의 값을 계산해야 한다.

는 i 모선의 유효전력 변화량에 따른 계통 전체의 손실변화량이다. To calculate TLF _i

We need to calculate the value of.

Is the loss change of the whole system according to the active power change of i bus.

의 계산을 위해서는 계통의 손실에 관한 함수인 P_loss를 알아야 한다. 비선형성이 큰 전력계통의 특성상 P_loss 함수를 알기 어렵다. 그러나, 계통 해석 방법 중 하나인 전력조류계산을 수행하면, P_loss의 함수는 알 수 없어도, P_loss의 값은 구할 수 있다.

To calculate, we need to know P _loss which is a function of system loss. It is difficult to know the P _loss function due to the characteristics of power system with large nonlinearity. However, if we perform power flow calculation, one of the system analysis methods, the value of P _loss can be obtained even though the function of P _loss is unknown.

In order to use the P _loss obtained through the power current calculation, Equation 1 is modified and expressed as Equation 2.

The active power of the i bus is the active power generation of the i bus minus the active power load of the i bus. Therefore, the change amount of the active power of the i bus will be the change amount ΔP _{G, i} of the active power generation amount of the i bus or the change amount ΔP _{l, i} of the active power load of the i bus. When the change in the active power of the bus is regarded as the change in generation amount and the load change amount, the change amount is the same but the sign is reversed.

The loss change of the whole system refers to the change of the whole system loss when the change occurs by ΔP _{G, i} or ΔP _{l, i} in the i bus. This system-wide loss change can be calculated from the amount of effective power generation of the slack bus that covers the entire system loss in the power current calculation. If the power generation is increased by ΔP _{G, i} at the i bus and the power flow calculation is performed, the slack bus must bear all the changes in the system. Therefore, the effective power generation amount of the slack bus must be reduced from the existing generation amount by ΔP _{G, i,} which is the generation of the changed i bus, and must be additionally _handled by ΔP _loss , the loss of the entire system. This is in turn equal to the amount of change in the slack bus (ΔP _slack ). According to this process, the final equation is shown in Equation 3.

ΔP _{l, i} is the amount of change in the effective power load by the unit load of the i generation bus. ΔP _slack is the amount of slack bus power required to supply unit load of power bus. Equation 3 may be modified and expressed as Equation 4.

Here, P _{l, i} represents the active power load of the i bus that is changed after varying the load of the i power generation bus by a small unit. P _{l, base} represents the active power load of the i bus before changing the load of the i generation bus by a small unit. P _{slack, i} represents the effective power generation amount of the slack bus after the unit load of i generation bus is variable. P _{slack, base} represents the active power generation amount of the unit load variable electric power of the i power generation bus and the slack bus.

At this time, ΔP _{l, i} is a change amount artificially applied to the grid for calculating the transmission loss coefficient (TLF), and thus ΔP _slack is generated by ΔP _{l, i} . ΔP _slack is calculated by P _{slack, i} and _{P slack, base, P slack,} i and P _{slack, base} is calculated by the power flow computation.

)모선의 단위부하 변동에 따른 변화를 슬랙모선의 발전기가 전부 감당하게 된다. 이러한 특성 때문에 송전손실계수(TLF)는 슬랙모선에 따른 상대적인 값으로 나타나게 된다. 슬랙모선에서 단위부하가 변동하는 경우, 슬랙모선의 발전기가 변동한 단위부하에 손실없이 전력공급이 가능하기 때문에 슬랙모선의 송전손실계수(TLF)는 항상 1이다. 일반적으로, 부하집중지역에서 기준발전기에 비해 송전손실이 작은 발전기는 송전손실계수가 1보다 크고, 발전집중지역에 있어 기준발전기에 비해 송전손실이 큰 발전기는 송전손실계수가 1보다 작다.As described above, when calculating the transmission loss coefficient (TLF) using the power current calculation,

The generators of the Slack busbar are responsible for all the changes caused by the change in the unit load of the busbar. Because of this characteristic, the transmission loss coefficient (TLF) is expressed as a relative value along the slack bus. If the unit load in the slack bus fluctuates, the transmission loss coefficient (TLF) of the slack bus is always 1 because the generator of the slack bus can be supplied without loss in the fluctuating unit load. In general, a generator having a smaller transmission loss than a reference generator in a load intensive region has a larger transmission loss coefficient than 1, and a generator having a larger transmission loss than a reference generator in a power generation concentrated region has a transmission loss coefficient of less than one.

Since the transmission loss coefficient (TLF) is relative to the reference bus (slack bus), the value of the transmission loss coefficient (TLF) changes according to the position of the reference bus. The transmission loss factor of the current power exchange is calculated based on the high pressure of the surrounding pressure of the power plant, and the reference buses are set to Boryeong Thermal Power Plants 3 ~ 6 and Jeju Thermal Power. Reference bus (slack bus) in this specification also follows this setting.

Based on the above description, the transmission loss coefficient providing method and apparatus through power system component modeling and big data processing according to an embodiment of the present invention will be described.

1 is a block diagram schematically showing the configuration of a transmission loss coefficient (TLF) providing apparatus according to an embodiment of the present invention, Figure 2 is a flow chart showing an operation method of the transmission loss coefficient (TLF) providing apparatus of FIG. FIG. 3 illustrates a data extraction and classification process according to an embodiment of the present invention, and FIG. 4 illustrates modeling of a fixed shunt capacitor and a switched shunt capacitor according to an embodiment of the present invention. FIG. 5 is a diagram illustrating FACTS (Flexible AC Transmission System) facility modeling according to an embodiment of the present invention, and FIG. 6 is a diagram illustrating HVDC (High Voltage Direct current) modeling according to an embodiment of the present invention. 7 and 8 are diagrams illustrating 2 Winding Transformer modeling according to an embodiment of the present invention, and FIG. 9 is a diagram illustrating 3 Winding Transformer modeling according to an embodiment of the present invention.

First, referring to FIG. 1, the apparatus for providing a transmission loss coefficient (TLF) 100 calculates a data converter 101, a system configuration modeling unit 103, a power current calculation unit 105, and a transmission loss coefficient (TLF). The unit 107 and the output unit 109 is included. A description will be given of a series of processes in which these components are connected to each other to calculate and provide a transmission loss coefficient (TLF).

1 and 2, the data converter 101 receives power system data (S101). At this time, the power system data is used for the power system simulator for engineering of the power exchange (hereinafter referred to as 'PSS / E') system data to secure the reliability of the transmission loss coefficient (TLF). . Power system data includes bus information, generator information, line information and transformer information.

The PSS / E software tool is a power system analysis program developed by Siemens Power Technologies International. The PSS / E software tool is a software tool for simulating, interpreting, and optimizing power system characteristics, such as grid and power generation evaluation, in both steady and dynamic conditions. It can approximate the entire power system.

PSS / E system data is typically in the form of Power Flow Raw data. This type of data holds all the data for the input of the PSS / E. However, in order to utilize it, it is inefficient because all components supported by PSS / E must be modeled. PSS / E receives data in Power Flow Raw data format, performs power flow calculation, and then converts the result into Power Flow data format in Institute of Electrical and Electronics Engineers (IEEE) format. Can be stored. IEEE format data follows the configuration and format of the power flow calculation data standardized by the IEEE. PSS / E calculates and provides values in advance for some models in order to store data in accordance with IEEE format while raw data is input. Therefore, if the IEEE format is used, it is not necessary to model all the components supported by the PSS / E, and some components use the results already calculated in the PSS / E, so that modeling can be simplified and efficient. Therefore, IEEE format power flow data of PSS / E is used as input data.

The data conversion unit 101 extracts data necessary for calculating the transmission loss coefficient (TLF) from the data input in step S101 (S103).

As shown in (a) of FIG. 3, the PSS / E IEEE format power flow data includes data that is not necessary for calculating a transmission loss factor such as an area number, a zone number, a rate a, a rate b, a rate c, and the like. .

Therefore, the data converter 101 extracts only data necessary for calculating the transmission loss coefficient (TLF) in order to reduce the storage space of the apparatus 100 and improve the speed (S103). The extracted data is classified according to the type of data for easy input and processing by the transmission loss coefficient (TLF) calculation unit 107 developed by a commercial program MATLAB (S105). At this time, they are classified into letters and numbers according to the data format, and classified into BUS data and BRANCH data according to the type of data for efficient data processing. That is, the data converter 101 classifies the extracted data into three files of bus data, bus data, branch data, and bus name data. The classified file is stored in a text file (txt) format so that the classified file can be easily input from the matlab (S107).

This is because PSS / E IEEE format Power Flow data is difficult to receive data from MATLAB in DAT file format. The data conversion unit 101 is developed by Visual Studio C ++, which is a commercial program effective for reading PSS / E data, but is not limited thereto, and other programming languages may be used.

In this way, the storage space of the device 100 can be reduced and the speed can be improved.

On the other hand, in order to perform power flow calculation with PSS / E data, power system components must be modeled in the form of P, Q, V, δ, and Y in the same manner as PSS / E. The calculation of the transmission loss coefficient (TLF) is calculated by giving a small change to the system data converged by the power current calculation and performing the power current calculation again. Therefore, even if the model can be modeled exactly the same as the PSS / E, the calculation results are hardly changed since only a small change is given to the PSS / E IEEE format power flow data, which is already converged result data. Therefore, making all processes of power system components the same as PSS / E can slow down the computation by adding unnecessary calculations.

The system configuration modeling unit 103 models the components of the power system so that the power current calculation to be performed for the transmission loss coefficient calculation can be performed in a matlab environment (S109). In this case, in order to model the power system components, power system components are modeled through an efficient method so as to simplify the calculation process while achieving the purpose of calculating the transmission loss coefficient.

In order to perform power flow calculations for a real system, all components in the real system must be modeled. When constructing power system data with PSS / E, the power exchange modeled various components of the actual system in a form that can be interpreted in PSS / E. Therefore, since the device 100 uses the PSS / E data of the power exchange as an input, the system modeling unit 103 does not need to model all the actual system components, but only the components considered in the PSS / E data. Modeling can be limited. At this time, the modeling method of the components are various, but the components are modeled in the same way as the PSS / E in order to reduce the error with the PSS / E which is a proven system analysis program. Specific modeling is the same as FIG. 4, 5, 6.

First, referring to FIG. 4, modeling of a fixed shunt capacitor and a switched shunt capacitor is illustrated.

In the power system, a fixed shunt capacitor and a switched shunt capacitor are mainly connected in parallel to improve power factor as shown in FIG. In the case of a fixed shunt capacitor, the capacity of the connected capacitor is constant, whereas in a switched shunt capacitor, the capacity of the capacitor varies with the voltage of the bus. In PSS / E, both shunt capacitors are modeled as being connected in parallel to the bus bar of the system. Accordingly, the fixed shunt capacitor and the switched shunt capacitor may be represented in the form as shown in FIG. 4B, which is modeled as the admittance of the bus (y _{s, i} ).

If y _{s, i} is the shunt capacitor admittance of the i bus, and Y _ii is the i-th diagonal component of the Y bus matrix, the equations are as follows.

Here, G _{s, i} is the conductance of the shunt capacitor of the i bus, j is the symbol representing the imaginary power, and B _{s, i} is the susceptance of the shunt capacitor of the i bus.

Where y _ii is the self admittance of the i busbar.

In the case of switched shunt capacitors, the PSS / E data provides the last input capacity data into the system. The calculation of the transmission loss coefficient (TLF) has only a small change in the whole system, so the input capacity of the switched shunt capacitor is hardly changed. Accordingly, the system modeling unit 103 models the switched shunt capacitor as a fixed shunt capacitor having a fixed final capacitance data.

Next, referring to FIG. 5, modeling of a flexible AC transmission system (FACTS) facility is illustrated.

The PSS / E data of the power exchange for the actual system models all of the FACTS facilities as either Static Var Compensator (SVC) or Static Condenser (STATCON). As shown in (a) of FIG. 5, the two equipments SVC and STATCON supply the reactive power to the bus within the limit of the capacity of the equipment to keep the voltage of the bus constant. In addition, unlike the shunt capacitor (Shunt Capacitor) does not change the admittance of the bus. Therefore, the systemic modeling unit 103 may model the FACTS facility as a load Q _i that consumes only reactive power as shown in FIG. 5. 5 (a) shows a FACTS facility on PSS / E. Figure 5 (b) is modeled as a load of the free power supplied by the FACTS facility of Figure 5 (a).

When calculating the transmission loss factor (TLF), there is only a small change in the whole system, so that the voltage of the bus remains almost unchanged. Therefore, since the amount of reactive power supplied by the FACTS facility is hardly changed, the systemic modeling unit 103 models the FACTS facility as a load having a fixed value. The IEEE Format Power Flow data of the PSS / E does not distinguish the reactive power supplied by the FACTS facility, and stores the value of the reactive power added to the load of the bus. Since IEEE Format Power Flow data already calculates the reactive power amount and provides the value, detailed modeling for determining the reactive power amount is not necessary.

Referring to FIG. 6, high voltage direct current (HVDC) modeling is illustrated.

In the PSS / E power system data, the active power transmitted from the bus to the HVDC line is controlled to always transmit the same amount of active power. Therefore, as shown in (a) of FIG. 6, the amount of active power transmitted from the power transmission stage and the amount of active power received from the power receiver are constant. In addition, since there is only a small change in the entire system when calculating the transmission loss coefficient (TLF), the amount of reactive power appearing at the entrance and exit of the HVDC is hardly changed. Accordingly, the systemic modeling unit 103 models the HVDC as a virtual load that receives the IEEE Format Power Flow data of the PSS / E. Here, the virtual load is modeled as a load that consumes algae exiting the DC line from the power transmission bus and a negative load supplying the algae coming from the DC line to the power receiving bus, as shown in FIG.

Here, P _{DC, i} is the active power outgoing from the i bus to the DC line, P _ij is the i-bus virtual load active power of the HVDC transmitting power from the i bus to j bus.

Here, P _{DC, j} is the active power coming into the j bus from the DC line, P _ji is the j bus virtual load active power of the HVDC transmitting power from the i bus to j bus.

Here, Q _{DC, i} is reactive power outgoing from the i bus to the DC line, and Q _ij is the i-bus virtual load reactive power of the HVDC transmitting power from the i bus to the j bus.

Here, Q _{DC, i} is reactive power coming into the j bus from the DC line, and Q _ji is the j bus virtual load reactive power of the HVDC transmitting power from the i bus to the j bus.

Algae flowing through the HVDC also hardly change, since there is only a small change in the overall system when calculating the transmission loss coefficient (TLF). Therefore, the magnitudes of the two loads, the equivalent model of HVDC, are constant when calculating the transmission loss coefficient (TLF). HVDC, as with the FACTS facility, uses the PSS / E's IEEE Format Power Flow data to provide two virtual loads in addition to each bus's load. Since IEEE Format Power Flow data of PSS / E is already provided by calculating the current value flowing through HVDC, detailed modeling considering Rectifier, Inverter, etc. is not necessary.

7 and 8, 2 Winding Transformer modeling is shown. The 2 Winding Transformer data of the PSS / E includes information on the equivalent impedance (admittance) of the Transformer and the Turn Ratio of the primary and secondary transformers, which can be expressed as shown in FIG. 7.

If y _ij is the equivalent admittance of the transformer, a _ij is the Turn Ratio, and V _i and V _j are the voltages of the i bus and the j bus, the currents I _ij and I _ji are

The right side left matrix of Equation 11 represents a Y Bus Matrix. Accordingly, the 2 Winding Transformer may be equivalent to two shunt capacitors and one line admittance as shown in FIG. 8.

The equivalent admittance is represented by y '.

Finally, referring to FIG. 9, 3 Winding Transformer modeling is shown. In PSS / E, 3 Winding Transformer was modeled as 3 2 Winding Transformers by adopting a virtual point star point bus. PSS / E data provides information about the Star Point Bus. The Star Point Bus is modeled as the secondary side load bus of three 2 Winding Transfomers.

Referring back to FIGS. 1 and 2, the power flow calculator 105 performs power flow calculation by applying component modeling in operation S109.

Power current calculation is calculated using only P, Q, V, δ, and Y. 4 to 9, the power system components are converted into elements of P, Q, V, δ, and Y.

The power current calculation unit 105 calculates P _slack through the power current calculation (S111 and S113).

)을 증가시킨다(S111). 이때, 단위부하의 유효전력 변화량은 PSS/E 데이터의 부하 단위가 MW임을 고려하여 1MW의 부하 증가로 설정될 수 있다.At this time, P _slack includes a change that occurs due to the variable unit load of the power generation bus. Accordingly, the power current calculation unit 105 sequentially changes the effective power load by the unit load for all power generation buses included in the system data.

Increase (S111). At this time, the amount of change in the effective power of the unit load may be set to increase the load of 1MW considering that the load unit of the PSS / E data is MW.

The power flow calculator 105 calculates the P _slack through the power flow calculation after the unit load is varied in step S111 (S113). Here, P _slack is generated by ΔP _{l, i} increased (S111), as described in Equation 4. Since ΔP _slack is calculated by P _{slack, i} and P _{slack, base} , the power flow calculator 105 calculates P _{slack, i} (after unit load variable) and P _{slack, base} (before unit load variable). .

At this time, according to an embodiment, the power current calculation unit 105 may use the Full AC power current calculation method, and may use the Newton-Raphson method as a solution of the power current calculation. Here, the Newton-Raphson method is used for large scale systematic analysis because of its good convergence. Using the Newton-Raphson method, the speed of the transmission loss factor calculation program is determined by the computational speed associated with the Jacobian matrix. One of the commercial programs, MATLAB, uses a matrix-based language and provides functions for inverse matrix solving and AX = B matrix equations. Using these functions can shorten the time required for calculations related to Jacobian matrices, so that the power flow calculator 105 can perform operations using MATLAB.

In addition, the power current calculation unit 105 calculates the P _{slack, the base} and the slack bus first in consideration of the efficiency of the transmission loss coefficient calculation, the simplicity of programming, the ease of comparison between the transmission loss coefficient. P _{slack, base} is the amount of active power generation of the slack bus when there is no fluctuation of micro load. P _{slack, i} should be calculated every time by changing the current i, but P _{slack, base} always has the same value regardless of i. Therefore _, it is inefficient to recalculate P _{slack, base} every i-th, so the value is stored and used after one calculation. The calculation point of P _{slack, base} is that the transmission loss coefficient of Slack bus is always 1. If we set the slack bus to be i = 1, it is meaningless to calculate P _{slack, i} since we know that the result of the transmission loss factor at i = 1 is 1. Instead, when i = 1, if P _{slack, base} is calculated without any load change on any bus, there is no need to program coding to get P _{slack, base} for calculating the transmission loss factor from i = 2. The efficiency of transmission loss factor calculation and the simplicity of programming are increased. In addition, since the information about the name of the bus, PSS / E bus number, and transmission loss coefficient (= 1), which is the basis of the transmission loss coefficient, is outputted first as a result, the ease of comparison between the transmission loss coefficients is increased.

The convergence condition of the power current calculation takes into account that the transmission loss coefficient is determined by the amount of active power generation of the slack bus. Therefore, the termination condition is used as the deviation of the active power and the reactive power, not the deviation of the voltage and phase angle. Can be.

의 값은 전력조류계산의 정확성과 수렴성 및 속도를 고려하여 실험적으로 결정한다. 이때, 본 발명의 실시예에서

값은 10^-7으로 설정하였다.

The value of is determined experimentally taking into account the accuracy, convergence and speed of the power current calculation. At this time, in the embodiment of the present invention

The value was set to 10 ⁻⁷ .

The transmission loss coefficient (TLF) calculation unit 107 calculates a transmission loss coefficient (TLF) of an arbitrary (i) power generation bus based on the calculated effective power generation amount P _{slack, i} of the Slack bus (S113) ( S115).

The output unit 109 outputs a transmission loss coefficient (TLF) for each bus line on the screen (S117).

The transmission loss coefficient (TLF) calculation unit 107 increases the index i of the bus bar by one (i + 1) (S119). The transmission loss coefficient (TLF) calculation unit 107 determines whether the increased index i is smaller than the total number of power generation buses included in the PSS / E IEEE format system data input in step S101 (S121). If small, it starts again from step S111. If not small, the output unit 109 outputs the transmission loss coefficient (TLF) calculation result calculated in step S115.

Then, the output unit 109 stores the transmission loss coefficient (TLF) calculation result for each bus index in an Excel format file (S123). That is, the bus name, PSS / E power generation bus number, and transmission loss coefficient (TLF) may be generated and stored in an Excel format file for each bus index. According to one embodiment, the output unit 109 transmits the final result of the transmission loss coefficient (TLF) provided from the transmission loss coefficient (TLF) calculation unit 107 PSS / E power generation bus number, power generation bus name, power transmission loss coefficient (TLF) can be saved as 'result_TLF.csv', an Excel file.

In addition, the output unit 109 may output the calculation progress up to the present through the user interface, for example, immediately after the steps S115 and S121 during the calculation process. At this time, the output unit 109 sequentially displays the transmission loss coefficient (TLF) calculation information including the bus name, the bus index, the transmission loss coefficient (TLF) calculation progress rate, the power current calculation result, and the transmission loss coefficient according to the bus index. Can be marked on.

Here, the transmission loss coefficient (TLF) calculation progress rate is calculated as the ratio of the current bus index and the number of power generation buses to be calculated for the transmission loss coefficient (TLF). That is, the current bus order is calculated by dividing the total transmission loss coefficient (TLF) by the number of buses.

10 is a block diagram showing a hardware configuration of a transmission loss coefficient (TLF) providing apparatus according to another embodiment of the present invention, and shows a configuration of the transmission loss coefficient (TLF) providing apparatus 100 described with reference to FIG. 1.

Referring to FIG. 10, the apparatus 200 for transmitting power loss coefficient (TLF) provides a memory 201, a storage device 203, an input device 205, an output device 207, and at least one processor 209. It is composed of the hardware included, the program is stored in the specified place to be executed in combination with the hardware.

The processor 209 executes a program stored in the memory 201. The program includes instructions for executing the configuration and / or the method according to the embodiments described with reference to FIGS. 1 to 9, and the processor 209 may be combined with hardware such as the memory 201 to implement the present invention. Run

The storage device 203 stores the operation result of the processor 209. For example, you can store the results of the TTL calculation in Excel file format.

The input device 205 is connected to the processor 209 and is a means for inputting data of a user according to the embodiments described with reference to FIGS. 1 to 9. The output device 207 is connected to the processor 209 to output data according to the embodiments described with reference to FIGS. 1 to 9 on the screen. For example, the output device 207 outputs the generation amount of the slack bus, the transmission loss coefficient, and the like for calculating the transmission loss coefficient on the screen.

The embodiments of the present invention described above are not only implemented through the apparatus and the method, but may be implemented through a program for realizing a function corresponding to the configuration of the embodiments of the present invention or a recording medium on which the program is recorded.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

Claims (12)

A transmission loss coefficient providing method performed in a transmission loss coefficient providing apparatus operated by at least one processor,
Receiving power flow data calculated through PSS / E (Power System Simulator for Engineering) and in the Institute of Electrical and Electronics Engineers (IEEE) format;
Classifying the power flow data into bus data, branch data, and bus name data;
Convert the categorized data into a text (txt) file format,
Modeling a component of a power system as a component according to the PSS / E based on the data converted into the text file format;
Varying an effective power load by a minute unit load with respect to an arbitrary power generation bus among a plurality of power generation buses included in the converted data,
Calculating an amount of change in the effective power generation amount of the slack bus required for supplying the variable effective power load and generated due to the change in the effective power load of the arbitrary power generation bus,
Calculating a transmission loss coefficient of the arbitrary power generation bus using the change amount of the unit load effective power of the arbitrary power generation bus and the change amount of the effective power generation power of the slack bus, and
Outputting the power loss factor through a user interface;
The variable step,
Each time the index of the arbitrary power generation bus increases, the effective power of the unit load is sequentially increased by 1MW,
The component modeling,
Switched Shunt Capacitors and Fixed Shunt Capacitors Modeled as Admittance with Fixed Capacitance, Flexible AC Transmission System (FACTS) Modeled as Reactive Power-Only Load, and PSS / A transmission loss coefficient providing method comprising at least one of a high voltage direct current (HVDC) modeled as a virtual load that takes the power flow data of E as an input. delete delete delete In claim 1,
The modeling step,
A method of providing a transmission loss coefficient for modeling a switched shunt capacitor as a fixed shunt capacitor having a fixed final capacity data. delete In claim 1,
The modeling step,
2 Power transmission loss factor providing method for modeling Winding Transformer with two shunt capacitors and one line admittance that input power flow data of PSS / E. In claim 1,
The modeling step,
A method of providing a transmission loss coefficient, which models a 3 Winding Transformer modeled as 3 2 Winding Transformers using an imaginary busbar as an admittance using PSS / E power flow data. delete Input unit that receives power flow data, which is calculated through PSS / E (Power System Simulator for Engineering) and is in the Institute of Electrical and Electronics Engineers (IEEE) format,
Output section for outputting the transmission loss coefficient of the power generation bus of the power system,
A memory for storing a program for calculating and outputting the transmission loss coefficient based on the power current data; and
At least one processor for executing the program,
The program,
The power current data is classified into bus data, branch data, and bus name data, and then the classified data is converted into a text file format.
Based on the data converted into the text file format, only a switched shunt capacitor, a fixed shunt capacitor, and a reactive power modeled in the form of an admittance form of a component of a power system with a fixed capacity According to the PSS / E including at least one of a flexible AC transmission system (FACTS) modeled as a consuming load, and a high voltage direct current (HVDC) modeled as a virtual load that inputs power flow data of the PSS / E. Model it as a component,
Based on the modeling, the effective power load of any power generation bus among the plurality of power generation buses included in the converted data is sequentially increased by 1 MW every time the index of the power generation bus is increased, and then the power current calculation Then,
Calculating the amount of change in the effective power generation amount of the slack bus that is required to supply the variable active power load and is generated due to the change of the active power load,
The transmission loss coefficient of the arbitrary power generation bus is calculated using the change amount of the unit load effective power of the arbitrary power generation bus and the change of the effective power generation amount of the slack bus, and the instructions are outputted through a user interface. Including, transmission loss coefficient providing apparatus.



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