WO2014038742A1 - Apparatus and method for estimating section loads in power distribution system - Google Patents

Abstract

Provided are an apparatus and method for estimating section loads in a power distribution system, which involve detecting and replacing error data in an actual measurement, considering the deviation in a diversity factor of an individual section, using current data, voltage data and phase data, and reflecting the loss caused by impedance, thereby estimating section loads in the power distribution system. The provided apparatus for estimating section loads in a power distribution system comprises: an error data processing unit for processing error data of acquired data in order to calculate an individual section load; a voltage estimation unit for estimating a voltage based on the calculated individual section load; a section load calculation unit for calculating an individual section load based on the calculated individual section load and the estimated voltage; a power flow calculation unit for calculating a voltage and phase based on the calculated individual section load, and calculating power flow information for each line based on the calculated voltage and phase; and a load pattern generating unit for generating a load pattern based on the calculated power flow information.

Description

Apparatus and method for estimating load on distribution system

The present invention relates to a section load estimation apparatus and method for distribution system (APPARATUS AND METHOD FOR ESTIMATING SECTION LOADS IN POWER DISTRIBUTION SYSTEMS), and more specifically, the system by the recovery of power failure section and system reconstruction, bird flow calculation, etc. An apparatus and method for estimating the interval load of a distribution system for estimating the interval load for grasping the current state.

Distribution system refers to a power system that converts the high voltage supplied from the power transmission system to a low voltage used in the customer to supply to the customer.

As shown in FIG. 1, in the power transmission system, the section load is measured through the direct measurement 11 for the load. In addition, the transmission system measures the measurement (12) of the amount of generation and the outflow and inflow measurement (13) of the pure line with the load removed. Therefore, in the transmission system, when a problem occurs in the direct measurement of the load, it is possible to estimate the section load using the remaining measurement amount (for example, the inflow of power generation, the outflow of the line, etc.).

On the other hand, as shown in Figure 2, in the case of the distribution system there is no measuring point except for the automatic switch 21. That is, in the case of the distribution system, it is possible to measure the voltage, current, and phase in the automated switchgear 21, but it is impossible to measure the voltage, current, and phase at the point 23 where the manual switch 22 is installed. In addition, in the distribution system, many loads are distributed between the automation switch 21 and the automation switch 21, and the measurement value for the line between the automation switch 21 and the automation switch 21 includes loads. It is impossible to estimate the load. Therefore, in the case of the distribution system, the section load is estimated through estimation of the dumped loads for the section 24 between the automatic switchgear 21.

The estimation of distribution system section load has the following importance in terms of system analysis and control.

1) Interpretation of distribution system: Calculation of tidal current of distribution system is a basic solution for identifying weak points (voltage and line algae). Algae calculation is a technique to determine the current system state (voltage and phase) based on load, and accurate estimation of section load is very important. Misinterpretation results in a loss of system operation if the error is detected or not detected at certain points of voltage and violation of line birds.

2) Distribution system planning: Network reconfiguration, a typical distribution system planning solution, also minimizes this by calculating load leveling and tidal flow-based losses based on each D / L (distribution line) load. Since the objective function is used, accurate estimation of the section load is a very important factor. In case of system planning with wrong section load, economic loss such as unnecessary line and equipment construction is expected.

3) Control of distribution system: In the event of a failure of the distribution system, fault isolation by the protection device, isolation of the fault section by the automatic switchgear, and restoration of the interruption section are performed sequentially. In order to recover the blackout section, information on the load of the blackout section and the loads of nearby lines that can be transferred are determined. Through this, whether and how to recover the blackout section is determined. The establishment of tracks and automated switchgear in the case of non-recoverable cases is considered, so inaccurate estimates of section loads lead to economic losses.

Thus, in the distribution system, unlike the power transmission system, since the load cannot be measured directly, the section load is estimated. Estimation of the section load in the distribution system is an essential factor for grasping the current status of the system by restoring the power failure section, reconfiguring the system, and calculating the current in case of system failure.

3 is a conventional distribution system section load estimation system. As shown in FIG. 3, the conventional distribution system section load estimation system collects and processes acquisition data acquired by a plurality of acquisition devices 31 and a plurality of acquisition devices 31 for acquiring site data from a distribution system. Request data collection by transmitting a data scan command to the data processing device 32 and the field data processing device 32, and receiving the acquired data collected by the field data processing device 32 to perform the section load. It comprises a main device 33 for estimating. At this time, the main device 33 includes an interval load estimating apparatus 34 for estimating the interval load using the received acquisition data, and a storage database 35 (hereinafter, stored DB) for storing the received acquisition data and the estimated interval load. It is configured to include.

4 is a flowchart illustrating a section load estimation method using a conventional distribution system section load estimation system. As shown in FIG. 4, the distribution system section load estimation system classifies an inflow / outflow measurement apparatus (S10). At this time, the distribution system section load estimation system distinguishes the inflow / outflow measurement device of a specific section by searching a topology path from the power supply side (DL lead end) to the load side on the premise that the system configuration is radial. .

Then, the distribution system section load estimation system calculates the deviation between the inflow and outflow by using the current measurement values of the divided measuring devices (S20). That is, the distribution system section load estimation system calculates the inflow amount using the current measurement values of the measuring devices divided into the inflow measurement device. The distribution system section load estimating system calculates the outflow amount by using the current measurement values of the measuring devices divided into the outflow measuring device. Then, the distribution system section load estimation system calculates the deviation between the inflow and outflow based on the calculated inflow and outflow.

The distribution system section load estimating system distributes the calculated inflows and outflows into individual sections to calculate the loads for the individual sections (S30), and stores the calculated loads for the individual sections in the temporary data storage daily (S40). .

When the daily data storage is completed (S50; Yes), the distribution system section load estimation system calculates and stores the maximum value during the week and the maximum value on the weekend (S60). That is, the distribution system section load estimating system calculates the maximum value (ie, the maximum value during the week) of individual section loads during the last five days of the week during the specific time every day, and loads the individual section loads on the last four weeks on Saturday and Sunday. Calculate the maximum of the calculated value (ie, weekend maximum). The distribution system section load estimation system stores the calculated weekly maximums and weekend maximums, and uses the maximums stored in system restoration and reconstruction and protection coordination.

The low accuracy of the section load estimation has a significant impact on the reliability and economics of distribution system operation. However, when the above-described conventional section load estimation technique is used, the section load is lowered in the accuracy of estimation in the distribution system, resulting in a problem of lowering reliability and economic efficiency. Therefore, a technique for increasing the accuracy of estimating the section load in the distribution system has been developed.

For example, in Korean Patent Registration No. 10-1132015 (name: distribution automation server supporting the failure recovery of the distribution line and method), the maximum, minimum and average current is calculated using the measured current of each switch, and each section The technique of calculating the section load by using the difference between the maximum current of the power supply switch and the load switching period is described.

In addition, in Korean Patent Registration No. 10-1026238 (name: method and system for determining the installation position of the attenuator, and a recording medium including the same), the section load amount is calculated by subtracting the drawn current value from the draw current value drawn in each section. It mentions a technique to make.

However, there is a problem in the prior art that there is no detection and replacement of bad data. That is, in the conventional section load estimation method, section load is estimated using actual measurements of the distribution system, but a large amount of error data exists in the actual measurement of the distribution system. In the conventional section load estimation method, the section load is estimated using the actual measured value including the error data as it is, so that a large number of errors occur in the deviation between the inflow and outflow. Therefore, when using the conventional section load estimation method, there is an error in the estimation of the individual load, so a method of detecting and replacing error data in the actual measurement is required.

In addition, the conventional section load estimation method stores only the maximum values of the weekdays and weekends of each section, and thus does not take into account the variation in inequality for each section. Therefore, in the conventional section load estimation method, the excessive load is calculated, and there is a problem that a large number of errors occur during system restoration, reconfiguration, and protection coordination.

In addition, the conventional section load estimation method does not use voltage and phase data for estimating section load, but uses only current data as a measured value. That is, since the inflow and outflow are determined according to the flow direction of the current by the voltage and its phase, it is necessary to estimate the interval load in the unit of reactive power (P / Q) considering the voltage and phase in order to determine the flow by the distributed power supply. However, in the conventional section load estimation method, since only the current data is used as a measurement value, there is a problem that an error occurs in the section load calculation by the output of the distributed power source.

In addition, in the conventional section load estimation method, there is a problem that an error occurs in section load estimation because the loss due to impedance in the section is not considered.

The present invention has been proposed to solve the above-described problems, and an object of the present invention is to provide an apparatus and method for estimating a section load of a distribution system which detects and replaces error data in actual measurements of the distribution system to estimate the section load. do.

Another object of the present invention is to provide an apparatus and method for estimating a section load of a distribution system, which estimates a section load in consideration of variation in inequality rate of individual sections of a distribution system.

Another object of the present invention is to provide an apparatus and method for estimating a section load of a distribution system, which estimates the section load using current data, voltage data, and phase data of the distribution system.

Another object of the present invention is to provide an apparatus and method for estimating a section load of a distribution system, which estimates the section load by reflecting a loss due to impedance in a section of a distribution system.

In order to achieve the above object, the section load estimation apparatus of the distribution system according to an embodiment of the present invention, an error data processing unit for processing the error data of the acquired data received from the field data processing device to calculate the individual section load; A voltage estimating unit estimating a voltage based on the individual section loads calculated by the error data processing unit; A section load calculator configured to calculate the individual section loads based on the individual section loads calculated by the error data processor and the voltage estimated by the voltage estimator; A tidal current calculation unit that calculates a voltage and a phase based on the individual section loads calculated by the section load calculation unit, and calculates tidal current information of each line based on the calculated voltage and phase; And a load pattern generator for generating a load pattern based on the algae information calculated by the algal calculation processor.

The error data processing unit configures the switch group by using the DL drawing breaker and the switch processing results during initial driving.

The error data processing unit configures the switch group by using the measurement quality when it is not the initial driving, but selects the switch units whose measurement quality is set to be reliable by the user or the error data processing unit, and selects voltage quality and current quality among the selected switch units. And the switch groups using the switch devices whose phase quality is all set to be reliable by the user or the error data processing unit.

The error data processing unit processes the error data by performing a phase consistency check and a current consistency check for each configured switch group.

The error data processing unit calculates the total load for each switch group by using the deviations of the inflow and outflow amounts of each of the configured switch groups, calculates the total load for the switch groups by using the nominal voltage, and individually calculates the total load for the switch groups. Individual section loads are calculated by distributing to section loads.

The voltage estimator configures a gain matrix by performing preprocessing on the individual section loads and the voltage and transformer taps calculated by the error data processor, and calculates and observes the standard deviation based on the individual section loads and the quality calculated by the error data processor. A gender test is performed, a covariance is calculated by constructing the gain matrix and the inverse of the gain matrix, and voltage estimation is performed using the calculated covariance.

The section load calculation unit configures an automatic switch group based on the measurement quality and the section loss, calculates the section loss based on the inflow current, the outgoing current and the line impedance of the group, and calculates the section on the basis of the calculated section loss. The total load of the group is calculated and the individual loads are calculated by allocating the total load to the individual loads.

The section load calculation unit configures the switch group by using the measurement values of the DL drawer breaker and the DG switch during initial driving, and when the initial driving is not the initial driving, the section load calculation unit configures the switch group only by the switch set to be reliable by the error data processing unit. .

The tidal current calculation unit calculates the difference value between the reference value and the calculated power inflow value of each line, and calculates the voltage magnitude and the voltage The amount of change is calculated and based on the calculated voltage magnitude and voltage phase, information on tidal current including line flow and loss amount of each line is calculated.

The load pattern generator generates weekday and weekend load patterns using the track tide and the loss amount calculated by the tide calculator.

In order to achieve the above object, the section load estimation method of the distribution system according to the embodiment of the present invention, by the error data processing unit to process the error data of the acquired data received from the field data processing apparatus to calculate the individual section load step; Estimating a voltage based on the calculated individual section load by the voltage estimating unit; Calculating, by the section load calculator, the individual section loads based on the calculated individual section loads and the estimated voltages; Calculating, by the tidal current calculation unit, a voltage and a phase based on the individual section loads and the individual section loads calculated based on the estimated voltage, and calculating tidal current information of each line based on the calculated voltage and phase; And generating, by the load pattern generation unit, a load pattern based on the algae information calculated by the algal calculation processing unit.

The step of calculating the individual section load by processing the error data includes generating, by the error data processing unit, a switch group based on a current driving state of the distribution system. A switch group is formed using the DL drawout breaker and the switch processing result.

The step of calculating the individual section load by processing the error data includes the step of configuring the switchgear group by using the measurement quality when the error data processing unit is not the initial driving, and the step of configuring the switchgear group includes the error data Selecting, by the processing unit, switchgears having the measurement quality set to be reliable by the user or the error data processing unit; And configuring, by the error data processing unit, switch groups using the switch units in which the voltage quality, the current quality and the phase quality among the selected switches are all set to be reliable by the user or the error data processing unit.

The step of calculating the individual section load by processing the error data includes processing the error data by performing a phase consistency check and a current consistency check for each configured switch group by the error data processor.

The step of calculating the individual section load by processing the error data may include calculating, by the error data processing unit, the total load for each switch group by using deviations of the inflow and outflow amounts of the configured switch groups; And calculating, by the error data processing unit, the calculated total load for each switchgear group to the individual section loads, and calculating the individual section loads. Calculate the total load.

The estimating of the voltage may include: configuring, by the voltage estimating unit, a gain matrix by performing preprocessing on the calculated individual section load, the voltage, and the transformer tap; Performing a observability check by calculating, by the voltage estimating unit, a standard deviation based on the calculated individual section load and quality; Calculating a covariance by generating the configured gain matrix and the inverse of the gain matrix by the voltage estimating unit; And performing, by the voltage estimating unit, voltage estimation using the calculated covariance.

The step of calculating the individual section load based on the calculated individual section load and the estimated voltage includes: configuring, by the section load calculating unit, an automatic switch group based on the measured quality and the section loss; Calculating, by the section load calculation unit, a section loss based on the inflow current, the outflow current, and the line impedance of the configured auto switch group; Calculating, by the section load calculator, the total load of the group of automatic switchgears based on the calculated section loss; And distributing the calculated total load to the individual loads by the section load calculation unit to calculate the individual section loads.

The calculating of the individual section loads based on the calculated individual section loads and the estimated voltage includes: configuring, by the section load calculation unit, a switch group by using the measured values of the DL drawing breaker and the DG switch during initial driving; And configuring, by the section load calculation unit, the switch group only with the switch set in which the measurement quality is reliable by the error data processing unit when it is not the initial driving.

Computing the tidal current information of each line, the tidal current calculation unit, the step of calculating the difference value between the power input amount reference value and the calculated value of each line; Calculating an amount of change in voltage magnitude and voltage phase on the basis of the calculated individual section load, the jacobean value, the jacobean inverse matrix, and the calculated difference value by the algal calculation processor; And calculating, by the tidal current calculation unit, tidal current information including line tides and loss amounts of each line based on the calculated voltage magnitude and voltage phase.

In the step of generating the load pattern, the load pattern generation unit generates the weekend and weekend load patterns using the calculated line current and loss amount.

According to the present invention, the apparatus and method for estimating the interval load of a distribution system can overcome the absence of an error data processing scheme of the distribution system of the existing system, thereby enabling more accurate load identification and data generation.

In addition, the section load estimation device and method of the distribution system can overcome the absence of the load pattern of the existing system to realize the system recovery, system reconfiguration and protection coordination correction through the supply of realistic load data considering the inequality rate There is.

The section load estimating apparatus and method of the distribution system will be able to calculate the load of the effective power unit considering the voltage, current and phase, and the load estimation considering the effect of the output of the distributed power supply. Accordingly, the apparatus and method for estimating the interval load of the distribution system can solve the problem that the load calculation using only the current data of the existing system does not reflect the distributed power output.

In addition, the apparatus and method for estimating the interval load of the distribution system can overcome the absence of the loss consideration of the existing system, and thus it is possible to calculate realistic load data considering the interval loss.

The section load estimating apparatus and method of the distribution system can more accurately calculate the line margin in the event of a system failure through more accurate section load calculation, thereby reducing the number of new lines and new equipment for system recovery.

The section load estimating apparatus and method of the distribution system can secure the economic feasibility of new line construction and equipment construction at the time of system planning or system reconstruction through more accurate section load estimation.

The device and method for estimating the section load of the distribution system can secure economic feasibility for new protection equipment by realizing protection coordination through more accurate section load calculation.

1 to 4 are diagrams for explaining a conventional section load estimation technique.

5 is a view for explaining a section load estimation apparatus of the power distribution system according to an embodiment of the present invention.

6 is a flowchart illustrating a method for estimating the interval load of a distribution system according to an embodiment of the present invention.

7 to 10 are flowcharts for explaining the error data processing step of FIG.

11 and 12 are flowcharts for describing the voltage estimation step of FIG. 6.

13 and 14 are flowcharts for explaining the section load calculation step of FIG. 6.

15 and 16 are flowcharts for explaining the tidal current information calculating step of FIG.

17 is a flowchart for explaining a load pattern generation step of FIG. 6;

18 and 19 are diagrams showing the results of testing by applying a random 10% change in the voltage, current and phase measurements of all automated switchgear.

20 and 21 are diagrams showing the results of testing by applying a random 20% change in the voltage, current and phase measurements of all automatic switchgear.

Hereinafter, the preferred 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 technical idea of the present invention. . First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

Hereinafter, a section load estimation apparatus for a distribution system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. 5 is a block diagram illustrating an apparatus for estimating the interval load of a power distribution system according to an embodiment of the present invention.

As shown in FIG. 5, the section load estimating system 100 of the distribution system includes a section load estimating apparatus 200 and a storage database 300 of the distribution system, and the section load estimating apparatus 200 of the distribution system is The error data processor 210, the voltage estimator 230, the section load calculator 250, the tidal current calculator 270, and the load pattern generator 290 are configured.

The error data processing unit 210 performs error data processing on the acquired data received from the field data processing apparatus 32.

The error data processing unit 210 generates a switch group according to a current driving state (that is, whether the error data processing is initially driven). To this end, the error data processing unit 210 processes the information related to the switch connected to the distributed power source (DG) in the distribution system. That is, the error data processing unit 210 searches for a switch and a line connected to the distributed power (hereinafter, referred to as a 'DG switch') when the distributed power is present in the distribution system. The error data processor 210 detects whether a line is pressurized by using a node and open / close state information of the switch. This is to prevent the section load calculation for the non-pressurized lines from among the lines of the distribution system.

Here, the error data processing unit 210 configures the switch group by using the processing result of the information related to the DL drawer breaker and the switch at the time of initial driving. That is, the error data processor 210 configures a switch group by using only the DL drawer and the previously detected DG switch.

The error data processor 210 selects a switch to participate in the configuration of the switch group by using the measurement quality when the initial driving is not performed. That is, the error data processing unit 210 selects the switch whose measurement quality is set to be reliable by the user or the error data processing unit 210 (that is, the switch whose measurement quality is "Good", "Manual", or "MGood"). do. Here, the measurement quality used in the embodiment of the present invention is as described in Table 1 below.

Table 1

number	Measurement quality	meaning	uses
One	Good	Reliable measurement	Use as is
2	Bad	The measure is not reliable	Discarded measure
3	Manual	User enters a value	Use input as is
4	Mgood	User forces the measure to be trusted	Use measure as is
5	MBad	User forces measure to untrusted	Discarded measure

The error data processor 210 detects the participating target switch based on the voltage quality, current quality and phase quality of the selected switch. At this time, the error data processor 210 detects a switch whose voltage quality, current quality and phase quality are set to be reliable by the modu user or the error data processor 210 among the selected switches as the participating target switch. The error data processor 210 configures a switch group by using the detected participation target switches.

The error data processor 210 performs a phase consistency check and a current consistency check for each switch group. That is, the error data processor 210 performs a phase consistency check based on the alga calculation result calculated in the previous execution. At this time, the error data processing unit 210 determines that the phase upper limit (1 to 4 upper limit) of the switch included in the switch group is different based on the tidal calculation result calculated in the previous execution, and determines the measurement quality of the phase as "Bad". Change to The error data processor 210 compares the inflow and outflow amounts of each switch group to perform a current consistency check for the switch group. At this time, the error data processing unit 210 changes the current measurement quality of all the switchgear of the corresponding switch group to "Bad" when the inflow amount is less than the outflow amount. At this time, if any of the consistency check results for each switch group is detected as a violation of the consistency check, the error data processing unit 210 repeatedly performs the selection or consistency check of the switch to participate in the switch group configuration described above.

The error data processing unit 210 calculates the total load of each generated group. That is, when the switch group configuration using the DL drawer breaker and the DG switch is completed or a consistency check violation does not occur, the error data processing unit 210 calculates the total load amount of each switch group. At this time, the error data processing unit 210 uses a deviation between the inflow and outflow amounts of the switch group, and in the case of voltage measurement, it is assumed that "Bad data" exists in almost all measurement values, and the switch is operated using a nominal voltage. Calculate the total load for each group. At this time, the error data processing unit 210 calculates the total load of each switch group through the following equation (1).

Equation 1

Here, SWGPi is the active power of the i-th automatic switchgear section, and SWGQi is the reactive power of the i-th automated switchgear section. aj is the inflow and outflow direction of the j-th automatic switchgear of the i-th section. In this case, aj is positive for inflow and aj is negative for outflow. Ij is the current of the j-th automated switch, and θj is the voltage / current phase difference of the j-th automated switch.

The error data processor 210 calculates the load of the individual sections by using the generated auto switch group and the total load of each group calculated. That is, the error data processing unit 210 distributes individual section loads by using the calculated total load for each switch group. At this time, the error data processing unit 210 distributes the individual section load through the following equation (2).

Equation 2

Here, LDPij is the active power of the i-th automatic switchgear section, LDQij is the reactive power of the i-th automated switchgear section, and Ni is the number of individual loads in the section.

The voltage estimator 230 performs voltage estimation using the initial load data and other measurements calculated by the error data processor 210. That is, the voltage estimator 230 performs preprocessing on the initial load data and other measured values calculated by the error data processor 210. In this case, the voltage estimator 230 performs preprocessing on the load of the individual section, which is the initial load data calculated by the error data processor 210, and the voltage and the transformer tap, which are other measurement values. The voltage estimator 230 performs a zero impedance line (ZBR) process based on the line impedance and the tie switch. That is, the voltage estimator 230 processes the link switch between the lines having a very small line impedance and the substation as a zero impedance line in order to minimize the occurrence of an error in the inverse matrix operation.

The voltage estimator 230 constructs a gain matrix using preprocessed initial load data and other measurements. That is, the voltage estimator 230 calculates a standard deviation using the individual section load calculated by the error data processor 210 and its quality, and performs an observability test. In this case, the voltage estimator 230 applies the order of Equation 4 below to use the weight used for calculating the standard deviation according to the quality of the individual section load.

Equation 3

Where W _manual is the weight for the user input, W _Mgood is the weight for the value entered by the user as "Good", and W _Good is for the value calculated as "Good." W _Sgood is the weight for the value treated as "Suspected Good."

The voltage estimator 230 selects a reference bus and forms a gain matrix. Thereafter, the voltage estimator 230 changes the structure by extending the preformed gain matrix into a full matrix. The voltage estimator 230 calculates a value of the gain matrix through the voltage and phase partial derivatives of each measurement, and generates an inverse of the gain matrix.

The voltage estimator 230 calculates covariance using the gain matrix. That is, the voltage estimator 230 calculates a covariance value using the calculated gain matrix value and the inverse matrix.

The voltage estimator 230 estimates a voltage that is a state variable by using the calculated covariance. That is, the voltage estimator 230 updates the state variable by calculating the change amount of the state variable (voltage) using the covariance value. At this time, the voltage estimating unit 230 updates the voltage value by calculating a change amount of the voltage, which is a state variable, using the calculated covariance value. Here, the voltage estimator 230 performs voltage estimation using Equation 4 below.

Equation 4

Here, V _{i + 1} is a calculated voltage at time t + 1, and V _i is a calculated voltage at time t. G is a gain matrix, H is a Hessian matrix, T is a transpose of the matrix, and W is a weight matrix.

The voltage estimator 230 adjusts the transformer tap by using the updated voltage value. At this time, the voltage estimator 230 performs transformer tap adjustment by using Equation 5 below.

Equation 5

Here, TapIni is a tap position of the transformer before estimation, and TapEst is a tap position of the transformer after estimation. VIni is the corresponding transformer secondary voltage before estimation and VEst is the corresponding transformer secondary voltage after estimation. TapStep is the gap between the taps of the transformer. At this time, the unit of the interval between the voltage and the tap (Tap) is a PU, the calculation result is represented by an integer (Interger) by cutting off the decimal point.

When the estimated voltage satisfies the convergence condition, the voltage estimator 230 ends the voltage estimation. If the estimated voltage does not satisfy the convergence condition, the voltage estimator 230 re-performs the voltage estimation using the above-described gain matrix configuration or covariance.

The section load calculator 250 calculates the section load based on the processing results of the error data processor 210 and the voltage estimator 230. To this end, the section load calculator 250 performs the processing of the measurement quality QC processed by the error data processor 210. That is, the section load calculation unit 250 processes the DG switch information and determines whether the track is pressurized.

The section load calculator 250 configures an automatic switch group using the measurement quality and the section loss. In this case, in the initial driving situation of the DG switchgear, the section load calculation unit 250 configures the switchgear group using only the measured values of the DL withdrawal breaker and the DG switchgear. The section load calculator 250 selects a switch to participate in the switch group group by using the measured quality when the driving condition is not the initial driving situation. That is, the section load calculator 250 selects a switch to participate in the switch group group using the measurement quality processed by the error data processor 210. At this time, the section load calculation unit 250 configures the switch group by using only the switch (that is, the switch whose measurement quality is “Good”) in which all the measurement quality is set to be reliable by the error data processing unit 210. That is, the section load calculator 250 configures a switch group by using only the switch whose voltage quality, current quality, and phase quality are all set by the error data processor 210 to be reliable.

The section load calculator 250 calculates a section loss. To this end, the section load calculator 250 updates the estimated voltage estimated by the voltage estimator 230 with the voltage of the switch. The interval load calculation unit 250 updates the switch measurement voltage by replacing the estimated voltage estimated by the voltage estimator 230 with the nominal voltage when the error data is processed. The section load calculator 250 calculates a switch group loss (that is, a section loss). That is, the section load calculator 250 calculates section loss using the inflow current and the outflow current and the line impedance of the switch section.

The section load calculator 250 calculates the total load of each group. That is, the section load calculation unit 250 calculates the switch group total load using the calculated switch section loss.

The section load calculator 250 calculates individual section loads. That is, the section load calculation unit 250 calculates the individual section load by distributing the calculated switch group total load to the individual loads.

The algal calculation processing unit 270 calculates algal information of each track. The algal calculation processing unit 270 constitutes the Y matrix of the tracks. To this end, the tidal current calculation unit 270 performs a zero impedance line (ZBR) process based on the line impedance and the associated switch. At this time, the tidal current calculation unit 270 processes the link switch between the lines having a very small line impedance and the substation as a zero impedance line in order to minimize the occurrence of errors in the inverse matrix calculation. The algal calculation processing unit 270 selects a reference bus bar. At this time, the tidal current calculation processing unit 270 selects a generator bus having the largest active power output as a reference bus. The tidal current calculation processing unit 270 configures the Y matrix, and sets the active power inflow reference value, the reactive power inflow reference value, and the control amount of each bus to be used for the iterative operation. At this time, the tidal current calculation processing unit 270 sets the control amount of the control equipment, such as a generator, a transformer.

The algal calculation processor 270 generates a Jacobean matrix. The algal calculation processing unit 270 generates the structure of the J11 part of the Jacobean matrix, and reconstructs it into a Full Jacobean matrix.

The algal calculation processing unit 270 calculates an inverse of the parasitic Jacobean matrix. To this end, the algal calculation processing unit 270 calculates a difference value between the power input amount reference value and the calculated value. That is, the tidal current calculation processing unit 270 calculates a difference value (ie, mismatch) between the reference value of power inflow and the calculated value in each bus. The algal calculation processor 270 generates Jacobean values using the Full Jacobean matrix, and calculates the Jacobean inverse matrix.

The tidal current calculation processor 270 calculates a voltage and a phase in which an error is minimized (ie, entered into a convergence range) based on the individual section loads calculated by the section load calculator 250. That is, the algal calculation processing unit 270 calculates the state variable change amount using the Jacobean value, the Jacobean inverse matrix, and the calculated difference value. At this time, the tidal current calculation unit 270 calculates the amount of change in the voltage magnitude and voltage phase which are state variables.

The algae calculating unit 270 calculates algae information of each line by using the calculated voltage and phase. That is, the algal calculation processor 270 updates the state variable by using the calculated state variable change amount, and determines whether the state variable is completely converged. At this time, the tidal current calculation processing unit 270 calculates tidal current information including the line tidal current and loss amount using the renewed state variables (ie, voltage magnitude and voltage phase) when the state variables are completely converged. Here, the algae calculation processing unit 270 repeatedly calculates the inverse of the above-described Jacobean matrix and updates the state variables when it is not in full convergence.

The load pattern generator 290 generates a load pattern based on the result of calculating the tidal current information of the tidal current calculation processor 270. That is, the load pattern generation unit 290 generates the weekday and weekend load patterns using the line tide and the loss amount calculated by the tide calculation processor 270. Here, weekday and weekend load patterns are used for grid reconstruction, grid recovery and protection coordination. To this end, the load pattern generator 290 determines the update target load pattern and detects the load pattern at the update target time. That is, the load pattern generator 290 determines the processing time point of the current section load data and determines how many parking weekdays and weekend patterns of the year should be updated. The load pattern generator 290 detects load pattern data (weekday / weekend load pattern data of the week during the year) from the storage database 300 at the present time.

The load pattern generator 290 calculates a load pattern by using the existing load pattern and the current value, and updates the previously stored load pattern with the calculated load pattern. That is, the load pattern generator 290 calculates the weighted average of the previous value and the current value by the ratio specified by the user for the load pattern data. Through this, the load pattern generator 290 calculates a load pattern. The load pattern generator 290 updates the data of the storage database 300 at that time with the calculated load pattern data.

Hereinafter, the section load estimation method of the power distribution system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. 6 is a flowchart illustrating a section load estimation method of a distribution system according to an embodiment of the present invention. 7 and 10 are flowcharts for describing the error data processing step of FIG. 6, and FIGS. 11 and 12 are flowcharts for explaining the voltage estimation step of FIG. 6. 13 and 14 are flowcharts for describing the section load calculation step of FIG. 6, and FIGS. 15 and 16 are flowcharts for explaining the tidal flow information calculation step of FIG. 6. FIG. 17 is a flowchart for describing a load pattern generation step of FIG. 6.

First, the error data processing unit 210 performs error data processing on the acquired data received from the field data processing apparatus 32 (S100). That is, as shown in FIG. 7, the error data processor 210 determines the current driving state (S111). At this time, the error data processing unit 210 determines whether the initial run state of the error data processing (initial run). At this time, if the initial drive state (S111; Yes), the error data processing unit 210 forms an initial automated switch group, and calculates the total load of each group (S113). If not in the initial driving state (S111; No), the error data processing unit 210 performs a consistency check (consistency check) for the current and phase (S115). Thereafter, the error data processing unit 210 generates an automated crock group and calculates a total load of each group (S117). The error data processing unit 210 calculates the load of the individual sections by using the generated automatic switch group and the total load of each group calculated (S119).

Referring to the error data processing step (S100) in more detail with reference to the accompanying drawings as follows. As shown in FIG. 8, the error data processing unit 210 processes information related to a switch (hereinafter, referred to as a 'DG switch') connected to distributed power in the distribution system (S120). That is, the error data processing unit 210 searches for a switch and a line connected to the distributed power supply when there is a distributed power supply in the distribution system.

The error data processor 210 detects whether a line is pressurized by using a node and switch open / close state information (S125). This is to prevent the section load calculation for the non-pressurized lines from among the lines of the distribution system.

During initial driving (S130; YES), the error data processing unit 210 configures a switch group by using a result of processing information related to the DL draw breaker and the switch (S135). That is, the error data processor 210 configures a switch group by using only the DL drawer breaker and the DG switch detected in step S120.

If not the initial drive (S130; No), the error data processing unit 210 selects the switch to participate in the configuration of the switch group using the measurement quality (S140). That is, the error data processing unit 210 selects the switch whose measurement quality is set to be reliable by the user or the error data processing unit 210.

The error data processor 210 detects the participating target switch based on the voltage quality, current quality and phase quality of the selected switch. At this time, the error data processing unit 210 detects the switch which is set to be reliable by the user or the error data processing unit all of the voltage quality, current quality and phase quality among the switch selected in step S140 to the participating target switch. The error data processor 210 configures a switch group by using the detected participation target switches (S150). Here, the steps of configuring the switch group (that is, step S150) will be described in more detail with reference to FIGS. 9 and 10.

The error data processing unit 210 extracts the line and the transformer number (S151).

The error data processor 210 determines whether the extracted line is processed. At this time, the error data processing unit 210 determines that the processing status indicator (Flag) of the extracted line is "1", the processing state, and "0" determines that it is not processed.

If the extracted line is in the unprocessed state (S152; YES), the error data processor 210 allocates the extracted line and the transformer to the n-th line and the n-th switch of the N group (S153). To this end, the error data processing unit 210 increases the group number N, and assigns the extracted line and transformer numbers to the n-th line and switch numbers of the N groups.

The error data processing unit 210 extracts a starting node (From Node) and an ending node (To Node) number of the extracted line (S154). That is, the error data processor 210 extracts the number of the start node and the end node, which are electrical nodes of the extracted line.

If the extracted start node and the end node are in the unprocessed state (S155; YES), the error data processing unit 210 adds the extracted start node and the end node to the node list Node_List (S156).

The error data processing unit 210 changes the state of the extracted start node and end node to the processing state (S157). That is, the error data processing unit 210 changes the processing status indicator Flag of the extracted start node and end node to "1".

Thereafter, the error data processor 210 increments the leading indicators g_number_snodes of the extracted start node and end node by 1 (S158).

At this time, if the leading indicator is less than the trailing indicator (S159; No), the error data processing unit 210 stores the retrieved automation switch and the line number in the final breaker group Group_Last_CB and the last branch group Group_Last_BR of the switch list SW_List. (S160). Thereafter, the error data processing unit 210 performs the operation again from the above-described step S151.

If the leading indicator exceeds the trailing indicator (S159; YES), the error data processor 210 increments the trailing indicator (g_number_pnodes) by one (S161).

The error data processing unit 210 extracts a node corresponding to the position of the trailing indicator from the node list (S162), and extracts a switch list connected to the extracted node (S163).

The error data processor 210 adds the automated switch included in the extracted switch list to the switch group list Group_SW_List (S164).

The error data processing unit 210 changes the state of the switch which is in the unprocessed state and the unopened state among the switches included in the extracted switch list to the processed state (S165), adds the opposite node to the node list (Node_List), and then precedes the indicator. Increase (S166).

When the processing for all the switch list is completed (S167; YES), the error data processing unit 210 extracts the line list connected to the extracted node (S168).

At this time, the error data processing unit 210 changes the unprocessed line to the processing state (S169), adds the opposite node to the node list, and increases the leading indicator (S170).

When the process for the line and the transformer is completed (S171; Yes), the error data processing unit 210 ends the configuration of the switch group. At this time, the error data processing unit 210 performs the process again from the above-described step S151 when the process for the line and the transformer is not completed.

The error data processor 210 performs a phase consistency check and a current consistency check for each switch group (S170). That is, the error data processor 210 performs a phase consistency check based on the alga calculation result calculated in the previous execution. At this time, the error data processing unit 210 determines that the phase upper limit (1 to 4 upper limit) of the switch included in the switch group is different based on the tidal calculation result calculated in the previous execution, and determines the measurement quality of the phase as "Bad". Change to The error data processor 210 compares the inflow and outflow amounts of each switch group to perform a current consistency check for the switch group. At this time, the error data processing unit 210 changes the current measurement quality of all the switchgear of the corresponding switch group to "Bad" when the inflow amount is less than the outflow amount.

At this time, if any of the consistency check results for each switch group is detected as a violation of the consistency check (S175; No), the error data processing unit 210 repeats the above steps S140 to S170.

When the switch group configuration using the DL drawer breaker and the DG switch is completed, or when the consistency check violation does not occur (that is, S175; YES), the error data processing unit 210 calculates the total load amount for each switch group (S180). At this time, the error data processing unit 210 uses a deviation between the inflow and outflow amounts of the switch group, and in the case of voltage measurement, it is assumed that "Bad data" exists in almost all measurement values, and the switch is operated using a nominal voltage. Calculate the total load for each group.

The error data processor 210 distributes individual section loads by using the calculated total load for each switch group (S185).

The voltage estimator 230 performs voltage estimation using the initial load data and other measurements calculated by the error data processor 210 (S200). That is, as shown in FIG. 11, the voltage estimator 230 is configured to calculate initial load data (ie, loads of individual sections) and other measurements (ie, voltage and transformer taps) calculated by the error data processor 210. The pretreatment is performed (S211). The voltage estimator 230 constructs a gain matrix using the preprocessed initial load data and other measurements (S213), and the voltage estimator 230 calculates covariance using the gain matrix. (S215). The voltage estimator 230 estimates a voltage that is a state variable using the calculated covariance (S217).

If the estimated voltage satisfies the convergence condition (S219; YES), the voltage estimator 230 ends the voltage estimation, and if the convergence condition is not satisfied, the above-described steps S213 to S217 are repeated to perform the voltage estimation again.

Referring to the voltage estimation step (S200) in more detail with reference to the accompanying drawings as follows. As shown in FIG. 12, the voltage estimator 230 performs a zero impedance line (ZBR) process based on a line impedance and a tie switch (S220). That is, the voltage estimator 230 processes the link switch between the lines having a very small line impedance and the substation as a zero impedance line in order to minimize the occurrence of an error in the inverse matrix operation.

The voltage estimator 230 calculates a standard deviation using the individual section load calculated by the error data processor 210 and the quality thereof, and performs an observability test (S225).

The voltage estimator 230 selects a reference bus (S230) and forms a gain matrix (S235). Thereafter, the voltage estimator 230 changes the structure by extending the preformed gain matrix into a full matrix (S240). The voltage estimator 230 calculates a value of the gain matrix through the voltage and the phase partial derivative of each measurement (S245) and generates an inverse of the gain matrix (S250).

The voltage estimator 230 calculates a covariance value using the calculated gain matrix value and the inverse matrix (S255), and calculates a state variable (voltage) change amount using the covariance value (S260). Update (S265). That is, the voltage estimator 230 updates the voltage value by calculating a change amount of the voltage, which is a state variable, by using the calculated covariance value.

Thereafter, the voltage estimator 230 adjusts the transformer tap Tap using the updated voltage value (S270).

When the voltage value is within the convergence range (S275; YES), the voltage estimator 230 ends the voltage estimation. If the voltage value does not fall within the convergence range (S275; NO), the voltage estimator 230 repeats the above-described step S245 to step S270 to perform the transformer tap adjustment again.

The section load calculator 250 calculates the section load based on the results of the error detection step S100 and the voltage estimating step S200 (S300). That is, as shown in FIG. 13, the section load calculation unit 250 performs the processing of the measurement quality QC processed in the error data processing step S100 (S312) and calculates the section loss (S314). . The section load calculator 250 configures an automatic switch group using the measured quality and the section loss, and calculates the total amount load of each group (S316). The section load calculation unit 250 calculates the individual load by distributing the calculated total load to the individual loads (S318).

The interval load calculation step S300 will be described in more detail with reference to the accompanying drawings. As shown in FIG. 14, the section load calculator 250 processes the DG switch information (S320), and determines whether the line is pressurized (S325).

If the initial driving situation (S330; Yes), the section load calculation unit 250 configures the switch group by using only the measurement value of the DL draw breaker and the DG switch (S335).

The section load calculator 250 selects a switch to participate in the switch group group using the measured quality when the driving condition is not the initial driving condition (S340). That is, the section load calculator 250 selects a switch to participate in the switch group group using the measurement quality processed by the error data processor 210.

In this case, the section load calculator 250 configures a switch group by using only the switch set to be reliable by the error data processor 210 (S345). That is, the section load calculator 250 configures a switch group by using only the switch whose voltage quality, current quality, and phase quality are all set by the error data processor 210 to be reliable.

The section load calculator 250 updates the estimated voltage estimated by the voltage estimator 230 with respect to the voltage of the switch (S350). The interval load calculation unit 250 updates the switch measurement voltage by replacing the estimated voltage estimated by the voltage estimator 230 with the nominal voltage when the error data is processed.

The section load calculation unit 250 calculates a switch group loss (S355). That is, the section load calculator 250 calculates section loss using the inflow current and the outflow current and the line impedance of the switch section.

The section load calculation unit 250 calculates the switch group total load amount (S360). That is, the section load calculation unit 250 calculates the switch group total load using the calculated switch group loss.

The section load calculator 250 calculates individual section loads (S365). That is, the section load calculation unit 250 calculates the individual section load by distributing the calculated switch group total load to the individual loads.

The algal calculation processing unit 270 calculates algal information of each track (S400). That is, as shown in Figure 15, the algal calculation processing unit 270 constitutes the Y matrix of the lines (S411), and generates a Jacobean matrix (S413). The algae calculation unit 270 calculates the inverse of the parasitic Jacobean matrix (S415), and the voltage of which the error is minimized (ie, in the convergence range) based on the individual section loads calculated by the section load calculation unit 250. And the phase (S417). The algae calculation processing unit 270 calculates algae information of each line using the calculated voltage and phase (S419).

Referring to the bird information calculating step (S400) in more detail with reference to the accompanying drawings as follows. As shown in FIG. 16, the tidal current calculation unit 270 performs a zero impedance line (ZBR) process based on the line impedance and the associated switch (S420). That is, the tidal current calculation processing unit 270 processes the link switch between the lines having a very small line impedance and the substation as a zero impedance line in order to minimize the occurrence of an error in the inverse matrix operation.

The algal calculation processing unit 270 selects a reference bus bar (S425). At this time, the tidal current calculation processing unit 270 selects a generator bus having the largest active power output as a reference bus.

The tidal current calculation processing unit 270 configures the Y matrix (S430), and sets the active power inflow reference value, the reactive power inflow reference value, and the control amount of each bus to be used for the iterative operation (S435). At this time, the tidal current calculation processing unit 270 sets the control amount of the control equipment, such as a generator, a transformer.

The algal calculation processing unit 270 generates the structure of the J11 portion of the Jacobean matrix (S440), and reconstructs it into a Full Jacobean matrix form (S445).

The tidal current calculation processing unit 270 calculates a difference value between the power input amount reference value and the calculated value (S450). That is, the tidal current calculation processing unit 270 calculates a difference value (ie, mismatch) between the reference value of power inflow and the calculated value in each bus.

The algal calculation processor 270 generates Jacobean values using the Full Jacobean matrix (S455) and calculates the Jacobean inverse matrix (S460).

The algal calculation processing unit 270 calculates the change amount of the state variable by using the Jacobean value, the Jacobean inverse matrix, and the calculated difference value (910). At this time, the tidal current calculation unit 270 calculates the amount of change in the voltage magnitude and voltage phase which are state variables.

The algal calculation processing unit 270 updates the state variable using the calculated state variable change amount (S470) and determines whether the state variable is completely converged (S475). At this time, if it is not a complete convergence (S475; No), the algal calculation processing unit 270 repeats the above-described step S450 to step S470. In the case of complete convergence (S475; Yes), tidal current information including track tide and loss amount is calculated using the updated state variable (S480).

The load pattern generator 290 generates a load pattern based on the result of calculating the tidal current information of the tidal current processor 270 (S500). That is, the load pattern generation unit 290 generates the weekday and weekend load patterns using the line tide and the loss amount calculated by the tide calculation processor 270. Here, weekday and weekend load patterns are used for grid reconstruction, grid recovery and protection coordination.

Referring to the load pattern generation step (S500) in more detail with reference to the accompanying drawings as follows. As shown in FIG. 17, the load pattern generator 290 determines an update target load pattern (S520). That is, the load pattern generator 290 determines the processing time point of the current section load data and determines how many parking weekdays and weekend patterns of the year should be updated.

The load pattern generator 290 detects a load pattern at an update target time point (S540). That is, the load pattern generator 290 detects load pattern data (weekday / weekend load pattern data of the week during the year) from the storage database 300 at the present time.

The load pattern generator 290 calculates a load pattern using the existing load pattern and the current value (S560). That is, the load pattern generator 290 calculates the weighted average of the previous value and the current value by the ratio specified by the user for the load pattern data. Through this, the load pattern generator 290 calculates a load pattern.

The load pattern generator 290 updates the previously stored load pattern with the calculated load pattern (S580). That is, the load pattern generation unit 290 updates the data of the storage database 300 at that time with the calculated load pattern data.

Hereinafter, a load estimation simulation result using the apparatus and method for estimating the interval load of a distribution system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In order to prove the technical improvements and effects of the apparatus and method for estimating the interval load of the distribution system according to the embodiment of the present invention, the estimation capability is verified using actual system data. The data used for verification uses actual data for 65 D / L of KJC jurisdiction. The load is randomly distributed using the measured data of the D / L lead-out end, the switch measurement is calculated through algae calculation, and the test is performed using the true value. Table 2 below describes the system data used in the test and its processing method.

TABLE 2

number	Item	Explanation
One	Target line	7 substations under KEPCO Jeju branch office and 65 D / L data
2	Test data	1-minute synchronous data for 2 weeks in November 2011 for each D / L (using D / L measurement data stored in EMS of power exchange)
3	Initial Automated Switch Measurement Method	1) The measurement data (P / Q) for each D / L is reported as the dump load of each D / L and distributed to the detailed load to perform algae calculation. Calculate Current and Phase
4	Calculation of Distributed Power Output	1) Add 4 distributed power sources (2 at Gimnyeong, 2 per Songd) and add 2 SVRs. 2) Simulate a situation where the output of distributed power varies by 25% in 5 minute increments.
5	Creating a Test Data Set	Prepare the true data set for every 5 minutes by using the result of 3 and 4 above.
6	Bad data test	1) Bad data injection test (observation test) of current and phase value: observation by inputting data of specific location 2) Current and phase QC bad data injection test (observation test): observation by inputting QC value of specific location 3) Random noise injection test: Test by injecting random noise into voltage / current / phase data of random location

1) Bad current value injection test result

Bad data was inserted in switch 252 of the test subject to be operated in Jeju branch and observe the estimated trend. As shown in Table 3 below, in case of switch 252, the true value is

TABLE 3

As a result, the estimated value at switch 252 was derived as shown in Table 4 below.

Table 4

As such, the test results using the apparatus and method for estimating the interval load of the distribution system according to the present invention estimate the value close to the true value, and it can be seen that there is no problem in the estimation of the measurement value of the automatic switchgear nearby.

2) Bad phase value injection test result

The bad phase data were inserted into switch 252 and switch 595 and the estimated trend was observed. As shown in Table 5 below, in case of switch 252, the true value is 182 degrees and the bad data of 92 degrees is input.

Table 5

As such, the test results using the apparatus and method for estimating the interval load of the distribution system according to the present invention estimate the value close to the true value, and it can be seen that there is no problem in estimating the measured value of the automatic switchgear nearby.

As shown in Table 6 below, in case of switch 595, the true value was 17.4 degrees and 197.4 degrees of bad data was input. As a result of the test using the apparatus and method for estimating the section load of the distribution system according to the present invention, a value close to the true value can be estimated, and it can be seen that there is no problem in the estimation of the measurement value of the automatic switchgear nearby.

Table 6

3) The situation where random noise is applied to voltage / current / phase measurement

18 and 19 are diagrams showing the results of testing the random 10% change in the voltage, current and phase measurements of all automatic switchgear. 18 is a diagram illustrating a voltage estimate, and FIG. 19 is a diagram illustrating a current estimate.

20 and 21 are diagrams showing the results of testing by applying a random 20% change value to the voltage, current and phase measurements of all automatic switchgear. 20 is a diagram illustrating a voltage estimate, and FIG. 21 is a diagram illustrating a current estimate.

As can be seen from the above technical verification, the section load estimation apparatus and method of the distribution system according to the present invention is the error data processing problem, which is the biggest vulnerability of the conventional method through detection and replacement of voltage, current and phase errors Overcome As shown in the above figure, we can see the result of following the true value even for the random noise of 20%. In addition, by performing the load estimation of the directional reactive power unit can be used directly in the analysis and control of the above-described distribution system, it can be used in power distribution planning, etc. by generating a load pattern. If the proposed system of the present invention is employed in the future, it will contribute to securing the efficiency and economics of the distribution system operation through more accurate grasp of the section load.

As described above, the apparatus and method for estimating the interval load of the distribution system can overcome the absence of the error data processing method of the distribution system of the existing system, thereby enabling more accurate load identification and data generation.

In addition, the section load estimation device and method of the distribution system can overcome the absence of the load pattern of the existing system to realize the system recovery, system reconfiguration and protection coordination correction through the supply of realistic load data considering the inequality rate There is.

The section load estimating apparatus and method of the distribution system will be able to calculate the load of the effective power unit considering the voltage, current and phase, and the load estimation considering the effect of the output of the distributed power supply. Accordingly, the apparatus and method for estimating the interval load of the distribution system can solve the problem that the load calculation using only the current data of the existing system does not reflect the distributed power output.

In addition, the apparatus and method for estimating the interval load of the distribution system can overcome the absence of the loss consideration of the existing system, and thus it is possible to calculate realistic load data considering the interval loss.

The section load estimating apparatus and method of the distribution system can more accurately calculate the line margin in the event of a system failure through more accurate section load calculation, thereby reducing the number of new lines and new equipment for system recovery.

The section load estimating apparatus and method of the distribution system can secure the economic feasibility of new line construction and equipment construction at the time of system planning or system reconstruction through more accurate section load estimation.

The device and method for estimating the section load of the distribution system can secure economic feasibility for new protection equipment by realizing protection coordination through more accurate section load calculation.

Although a preferred embodiment according to the present invention has been described above, it is possible to modify in various forms, and those skilled in the art to various modifications and modifications without departing from the claims of the present invention It is understood that it may be practiced.

Claims (20)

1. An error data processing unit for processing the error data of the acquired data received from the field data processing apparatus to calculate an individual section load;

   A voltage estimating unit estimating a voltage based on the individual section loads calculated by the error data processing unit;

   A section load calculator configured to calculate the individual section load based on the individual section load calculated by the error data processor and the voltage estimated by the voltage estimator;

   A tidal current calculation unit calculating a voltage and a phase based on the individual section loads calculated by the section load calculation unit, and calculating tidal current information of each line based on the calculated voltage and phase; And

   And a load pattern generator for generating a load pattern based on the tidal current information calculated by the tidal current calculating unit.
2. The method according to claim 1,

   The error data processing unit,

   An apparatus for estimating the load of a distribution system according to claim 8, wherein the switch group is configured by using a DL draw breaker and a switch processing result.
3. The method according to claim 2,

   The error data processing unit,

   If it is not the initial driving, configure the switch group using the measurement quality, but select the switches whose measurement quality is set to be reliable by the user or the error data processing unit, and among the selected switches, voltage quality, current quality and phase quality All of the apparatus for estimating the load distribution of a distribution system using switchgears which are all set as reliable by a user or the error data processor.
4. The method according to claim 2 or 3,

   The error data processing unit,

   Section load estimation device of the distribution system characterized in that for processing the error data by performing the phase consistency check and the current consistency check for each configured switch group.
5. The method according to claim 2 or 3,

   The error data processing unit,

   Computing the total load for each switch group by using the deviation of the inflow and outflow amount of each of the configured switch group, using the nominal voltage to calculate the total load for each switch group,

   And calculating the individual section load by distributing the calculated total load for each switch group to the individual section loads.
6. The method according to claim 1,

   The voltage estimator,

   Preprocess the individual section load and voltage and transformer tap calculated by the error data processor to construct a gain matrix, and calculate the standard deviation based on the individual section load and quality calculated by the error data processor to observe the observability And calculating the covariance by generating the configured gain matrix and the inverse of the gain matrix, and performing voltage estimation using the calculated covariance.
7. The method according to claim 1,

   The section load calculation unit,

   Comprising the automatic switch group based on the measurement quality and section loss, calculate the section loss based on the inflow current and the outgoing current and the line impedance of the automation switch group,

   And calculating the total load of the automation switch group based on the calculated section loss and distributing the total load to the individual loads to calculate the individual section loads.
8. The method according to claim 7,

   The section load calculation unit,

   In the initial operation, the switch group is formed by using the measurement values of the DL drawer breaker and the DG switch.

   In the case of not the initial drive, the load distribution unit of the distribution system, characterized in that for configuring the switch group only the switch set the measurement quality is reliable by the error data processing unit.
9. The method according to claim 1,

   The algal calculation processing unit,

   The difference between the reference value and the calculated power inflow reference value of each line is calculated, and the variation in voltage magnitude and voltage phase is calculated based on the individual section load, the jacobean value, the jacobean inverse matrix, and the calculated difference value calculated by the section load calculation unit. And tide information including line tide and loss amount of each line based on the calculated voltage magnitude and voltage phase.
10. The method according to claim 9,

    The load pattern generator,

    Section load estimation device of the distribution system, characterized in that for generating the week and weekend load pattern using the line tide and loss amount calculated by the tide calculation processing unit.
11. Calculating, by the error data processing unit, the error data of the acquired data received from the field data processing apparatus to calculate the individual section loads;

    Estimating a voltage based on the calculated individual section load by a voltage estimating unit;

    Calculating, by the section load calculator, the individual section loads based on the calculated individual section loads and the estimated voltage;

    A current calculation processing unit calculates a voltage and a phase based on the individual section load and the individual section load calculated based on the estimated voltage, and calculates the current information on each line based on the calculated voltage and phase. step; And

    And a load pattern generating unit, generating a load pattern based on the tidal current information calculated by the tidal current calculating unit.
12. The method according to claim 11,

    The step of calculating the individual section load by processing the error data,

    Generating, by the error data processing unit, a switch group based on a current driving state of a distribution system;

    In the generating of the switch group, the load distribution estimating method of the distribution system, characterized in that for configuring the switch group by using the DL draw breaker and the switch processing results.
13. The method according to claim 12,

    The step of calculating the individual section load by processing the error data,

    By the error data processing unit, if it is not the initial drive comprises the step of configuring a switch group using the measurement quality,

    Configuring the switch group,

    Selecting, by the error data processing unit, switchgears whose measurement quality is set to be reliable by a user or the error data processing unit; And

    And configuring, by the error data processing unit, switch groups using switchgears of which voltage quality, current quality and phase quality are all set to be reliable by the user or the error data processing unit among the selected switches. Section load estimation method of the distribution system.
14. The method according to claim 12 or 13,

    The step of calculating the individual section load by processing the error data,

    And a step of processing the error data by performing a phase consistency check and a current consistency check for each configured switch group by the error data processor.
15. The method according to claim 12 or 13,

    The step of calculating the individual section load by processing the error data,

    Calculating, by the error data processing unit, the total load for each switch group by using deviations of the inflow and outflow amounts of the configured switch groups; And

    Comprising the step of calculating the individual section load by distributing the calculated total load for each switch group to the individual section load by the error data processing unit,

    In calculating the total load for each switch group, the section load estimation method of the distribution system, characterized in that for calculating the total load for each switch group using a nominal voltage.
16. The method according to claim 11,

    Estimating the voltage,

    Configuring a gain matrix by performing the preprocessing on the calculated individual section load, the voltage, and the transformer tap by the voltage estimating unit;

    Performing a observability check by calculating a standard deviation based on the calculated individual section load and quality by the voltage estimating unit;

    Calculating a covariance by generating the configured gain matrix and the inverse of the gain matrix by the voltage estimating unit; And

    And performing a voltage estimation by the voltage estimating unit using the calculated covariance.
17. The method according to claim 11,

    Computing the individual section load based on the calculated individual section load and the estimated voltage,

    Configuring, by the section load calculation unit, an automatic switch group based on the measurement quality and the section loss;

    Calculating, by the section load calculation unit, a section loss based on the inflow current, the outflow current, and the line impedance of the configured auto switch group;

    Calculating, by the section load calculation unit, the total load of the group of automatic switches based on the calculated section loss; And

    And distributing the calculated total load to individual loads to calculate individual section loads by the section load calculating section.
18. The method according to claim 17,

    Computing the individual section load based on the calculated individual section load and the estimated voltage,

    Configuring a switch group by the section load calculation unit by using measurements of the DL draw breaker and the DG switch during initial driving; And

    The step load estimating method of the power distribution system, characterized in that the step load calculation unit, if the initial drive is not the initial drive, the step of configuring the switch group only with the switch is set to be reliable by the error data processing unit .
19. The method according to claim 11,

    Computing the tidal current information of each line,

    Calculating, by the tidal current calculation unit, a difference value between a reference value of power input of each line and a calculated value;

    Calculating an amount of change in voltage magnitude and voltage phase on the basis of the calculated individual section load, jacobean value, jacobean inverse matrix, and the calculated difference value by the algal calculation processor; And

    And calculating, by the tidal current calculation unit, tidal flow information including line tides and loss amounts of each line based on the calculated voltage magnitude and voltage phase.
20. The method according to claim 19,

    In the step of generating the load pattern,

    And the load pattern generation unit generates weekday and weekend load patterns using the calculated line current and loss amount.

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