JP3701797B2 - Power system power flow monitoring device - Google Patents

Description

（但し、Ｐ’；基準潮流データ格納部３４に格納されている当該負荷端の基準負荷）
次に、類似日Ｗｈ値の補正を行う（ステップＳ２）。
【００３９】
これは、上記Ｐwi、すなわち各末端負荷端の過去の負荷量の時間平均値（Ｗｈ）を、類似日Ｗｈ値を用いた以下の（４）式の補正計算により求める。
【数１】

尚、上記「前後移動平均値」とは、現在（例えば３：００）の有効電力（Ｗｈ）をＰ２とし、その前後の正時（正時０分の意味）、すなわち前正時（２：００）、後正時（４：００）の有効電力（Ｗｈ）を、それぞれＰ１、Ｐ３とした場合、前後移動平均値＝（Ｐ１＋Ｐ２＋Ｐ３）／３の計算式により得られる。
【００４０】
また、上記補正係数Ｋの算出には、過去記録データ格納部３６に格納されている末端負荷実績値（過去の各末端負荷量の時間平均値（Ｗｈ値））が用いられる。
【００４１】
次に、基準潮流データ格納部３４、設備データ格納部３５、及び過去記録データ格納部３６に格納されているデータに基づいて、各放射状系統の負荷総和（Ｗｈ値）を計算する（ステップＳ３）。
【００４２】
これは、上記ステップＳ２で補正した各末端負荷量の時間平均値（Ｗｈ値）ベースで、各放射状系統毎に、引き出し口送電線（又は系統変圧器）の潮流合計値（Ｗｈ値）を求め、この潮流合計値を上記ΣＰwi（過去の負荷量の時間平均値（Ｗｈ）の総和）とする。
【００４３】
そして、系統状態量格納部３１、及び設備データ格納部３５に格納されているデータに基づいて、末端負荷の供給源の自動探索を行う（ステップＳ４）。
これは、各負荷端が供給を受けている送電線引出し口、あるいは系統変圧器の常時計測値（テレメータ値；ＴＭ）を探索し、このテレメータ値を放射状系統の現在負荷量の合計値ΣＰn とするものである。このステップＳ４の処理については、後に図３を参照して詳細に説明する。
【００４４】
上記ステップＳ１〜ステップＳ４の処理によって、ΣＰn 、Ｐwi、ΣＰwiが求められたので、これより上記（２）式の演算を実行して各末端の負荷量（瞬時値）を推定計算できる（ステップＳ５）。
【００４５】
図３は、上記図２のステップＳ４の処理である末端負荷供給源の自動探索を行う処理を詳細に説明する為のフローチャートである。
同図において、まず、設備データ格納部３５に格納されているノード、ブランチ情報と、系統状態量格納部３１で収集／格納した系統状態を読み込む（ステップＳ１１）。
【００４６】
そして、負荷端の数の分だけ、以下のステップＳ１３〜ステップＳ１８の処理を繰り返し実行する（ステップＳ１２）。
すなわち、まず、当該ループ処理において処理対象とした負荷端が、既に探索済みのものであるか否かを判定する（ステップＳ１３）。探索済みである場合には（ステップＳ１３、ＹＥＳ）、次のループ処理へと移行する。
【００４７】
探索済みではない場合には（ステップＳ１３、ＮＯ）、続いて、当該負荷端に流れ込む各ブランチについて調べ、計測点のあるものを取出し（ステップＳ１４）、そこに実際に計測機器が装備されている（実装）か否かを判定する（ステップＳ１５）。
【００４８】
計測点に実際に計測機器が装備されている場合には（ステップＳ１５、ＹＥＳ）、当該計測点を当該放射状系統の電源供給源であると見做す（ステップＳ１６）。
【００４９】
計測機器が装備されていない場合には（ステップＳ１５、ＮＯ）、潮流が最大であるブランチの他端ノードを取出し（ステップＳ１７）、これを探索経路上（各末端負荷端から送電線引出し口または系統変圧器までに至る経路上）のノード情報としてメモする（ステップＳ１８）。
【００５０】
その後は、負荷端の数の分だけ、上記ステップＳ１３〜ステップＳ１８の処理を繰り返す。その際、上記メモしたノード情報を参照して利用する。
図４は、負荷予測部１３による末端負荷量の予測処理を説明する為のフローチャートである。
【００５１】
同図において、まず、管轄内総需要量の予測を行う（ステップＳ２１）。
これは、予め、至近過去の連続期間（例えば、２週間）の平日のみを対象にして、その気温（最高気温または最低気温）と管轄内総需要量との関係を近似した以下の線形回帰式（５）、（６）を、時間帯毎に（例えば１時間毎に）求めておく。
〈線形回帰式１〉
管轄内総需要_t ＝ａ_t ×最高気温＋ｂ_t （ｔ＝１〜２４）・・・（５）
〈線形回帰式２〉
管轄内総需要_t ＝ｃ_t ×最低気温＋ｄ_t （ｔ＝１〜２４）・・・（６）
そして、予測日の需要特性に応じて、以下の４つの予測式（７）〜（１０）のいずれかを選択／使用して、各時間帯の総需要予測値を計算する。その際、どの予測式を選択するかは、管轄内需要の変動特性に合わせて精度が良くなるように事前にオペレータ等が予測日の曜日種別、時間帯別に設定したデータに従って判断する。また、これら予測式では、予測対象日の予想気温、及び類似日の総需要と気温の実績を用いるが、これについても、類似日をいつにするかは（前日、前週、任意指定日等）、オペレータ等が事前に曜日種別または予測日個別に設定したデータに従って判断する。
〈予測式１〉

〈予測式２〉

〈予測式３〉
管轄内予測総需要_t ＝ａ_t ×予想最高気温＋ｂ_t （ｔ＝１〜２４）・・・（９）
〈予測式４〉
管轄内予測総需要_t ＝ｃ_t ×予想最低気温＋ｄ_t （ｔ＝１〜２４）・・・（１０）
尚、上記方法では、予め、線形回帰式を、平日のみのデータに基づいて求めているが、予測対象日は平日に限らない。土曜日、日曜日、祝日は、平日とは需要量が異なるが、上記平日のデータに基づいて作成された線形回帰式とほぼ平行な変化（傾きがほぼ同じ）になる傾向がある。これより、土曜日、日曜日、祝日についても、上記〈予測式１〉、〈予測式２〉のように、類似日実績と回帰式の傾きを用いて予測を行う式を用いれば、管轄内予測総需要_t を求めることができる。
【００５２】
上記ステップＳ２１の処理により管轄内総需要量の予測を行った後、続いて、各末端負荷量（瞬時値）を予測する（ステップＳ２２）。
これは、上記ステップＳ２１の処理によって求めた管轄内予測総需要量と、過去に負荷推定部１１によって推定され推定値格納部１２に蓄積されている末端負荷量（瞬時値）（以下、推定実績末端負荷量という）を用いて、以下の式（１１）によって各末端負荷量（瞬時値）を予測・演算する。その際、上記推定実績末端負荷量は類似日のものを用いるが、この類似日をいつにするか（前日、前週、任意日等）は、オペレータ等が事前に曜日種別または予測日個別に設定したデータにしたがって判断する。
【００５３】

（ｔ＝１〜２４，ｔｎ＝00:00 〜23:59 の60/n分間隔の時刻）
ここで、ｔｎ＝00:00 〜00:59 のｎ点は、ｔ＝１を使用
ｔｎ＝01:00 〜01:59 のｎ点は、ｔ＝２を使用
・ ・ ・ ・ ・
ｔｎ＝23:00 〜23:59 のｎ点は、ｔ＝２４を使用
そして、最後に、末端負荷量（瞬時値）の補正を行う（ステップＳ２３）。
【００５４】
これは、現予測時刻から過去のＮ周期分の予測値とその実績値との間の誤差を、予め設定されている許容値（実績値のｍ％）と比較して、この比較結果に応じて以下の補正を行う。
（ａ）連続して（同方向に）許容値を越えた場合
現予測時刻の実績値と予測値の比率にしたがって、将来（本日分）の各時刻の末端予測負荷量を補正する。すなわち、以下の（１２）式により末端予測負荷量の補正値tnを求める。
【００５５】
補正値tn＝（現時刻の実績値／現時刻の予測値）×予測値tn ・・・（１２）
（ｂ）上記（ａ）以外の場合
補正しない
更に、急激な変化、緩やかな変化等に柔軟に対応する為に、監視周期と許容値の組合せを複数定義できるようにして、これにしたがって補正するようにしてもよい。この方法を用いれば、例えば急激に変化する場合には比較的短い周期で補正が行われ、緩やかな変化のときには比較的長い周期で補正が行われるように設定することができる。
【００５６】
図５は、本発明の電力系統潮流監視装置を実現する情報処理装置のハードウェア構成の一例を示す図である。
同図において、情報処理装置２０は、ＣＰＵ２１、記憶部２２（可搬記憶媒体２２ａを含む）、メモリ２３、入出力インタフェース部２４等より構成される。
【００５７】
ＣＰＵ２１は、情報処理装置２０全体を制御する中央処理装置である。
記憶部２２は、少なくとも、上述した本発明の電力系統潮流監視装置の機能を実現するためのプログラムが記憶されているＨＤＤ等の記憶装置である。または記憶部２２は可搬記憶媒体２２ａとその駆動読み取り装置の組合せ（例えば、フロッピディスク（ＦＤ）とフロッピーディスクドライブ（ＦＤＤ））であってもよい。可搬記憶媒体２２ａには上記ＦＤの他にＣＤ−ＲＯＭ、メモリカード、ＤＶＤ、ＭＯ等がある。
【００５８】
メモリ２３は、記憶部２２に格納されているプログラムを一時的に記憶し当該プログラムをＣＰＵ２１に実行させる為のＲＡＭ等である。尚、メモリ２３には、当該プログラムをＣＰＵ２１が実行中に生じる各種データ（中間結果データ等）を一時的に記憶する記憶領域も存在する。
【００５９】
入出力インタフェース部２４は、上述した系統状態量格納部３１が電力系統１の各状態量を収集する為に、外部のネットワーク等に接続されている入出力インタフェースである。
【００６０】
更に、特に図示していないが、ディスプレイやキーボード等を備えていてもよい。
本発明は、電力系統潮流監視装置それ自体に限らず、コンピュータにより使用されたときに、上述した本発明の各実施形態の機能を実現させる為のプログラムが格納されたコンピュータ読出し可能な記録媒体（記憶媒体）として構成することもできる。
【００６１】
【発明の効果】
以上、詳細に説明したように、本発明の電力系統潮流監視装置によれば、負荷系の電力系統の監視において、常時計測値のとれない末端負荷量等を推定できるようにすることにより、負荷系電力系統の全ての線路潮流の定量的な自動監視が可能となる。更に、将来の系統の状態についても予測可能とすることができ、系統監視の精度及び効率の向上に寄与する。
【図面の簡単な説明】
【図１】本実施形態による電力系統潮流監視装置の構成の一例を示すブロック図である。
【図２】末端負荷量の推定方法を説明する為のフローチャートである。
【図３】末端負荷供給源の自動探索を行う処理を詳細に説明する為のフローチャートである。
【図４】末端負荷量の予測処理を説明する為のフローチャートである。
【図５】電力系統潮流監視装置を実現する情報処理装置のハードウェア構成の一例を示す図である。
【図６】電力系統の一例を示す概念図である。
【図７】従来の電力系統潮流監視装置の構成の一例を示す機能ブロック図である。
【符号の説明】
１０ 電力系統潮流監視装置
１１ 負荷推定部
１２ 推定値格納部
１３ 負荷予測部
１４ 予測値格納部
１５ 潮流算出部
１６ 系統信頼度判断部
３１ 系統状態量格納部
３４ 基準潮流データ格納部
３５ 設備データ格納部
３６ 過去記録データ格納部
２０ 情報処理装置
２１ ＣＰＵ
２２ 記憶部
２２ａ 可搬記憶媒体
２３ メモリ
２４ 入出力インタフェース部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power system flow monitoring device in a load system.
[0002]
[Prior art]
FIG. 6 is a conceptual diagram illustrating an example of a power system.
As shown in the figure, the power system is generally divided into a main system and a load system. The main system is a loop system, and the main system power supply control station or the like monitors the system. The load system is a radial system, and the load system power supply control station monitors the system for each radial system. In the figure, an A load system power supply control station and a B load system power supply control station are shown as an example. The backbone system and the load system are connected by a system transformer, and each radial system is supplied with power from the transmission line outlet of the system transformer.
[0003]
The radial system includes nodes, branches, end load ends, and the like.
A node is generally a facility (node) where current is gathered, and includes, for example, a bus, a branch point of a transmission line, a generator, and a phase adjusting facility.
[0004]
A branch is a facility in a section in which a current flows between nodes, and includes, for example, a transmission line, a transformer (system transformer, distribution transformer, step-up transformer, etc.). The terminal load terminal means equipment such as a distribution transformer and an extra high-volume customer.
[0005]
Hereinafter, the jurisdiction range of each load system power supply control station is referred to as “within jurisdiction”.
Here, since the measurement points are always provided in the backbone system, all information necessary for system monitoring can be obtained. In addition, the place where the equipment that measures power, current, voltage, etc. is installed is called “measurement point”, and the “measurement point” where the measured value can be obtained every short period (unit: several seconds) " The data obtained at the “constant measurement point” is referred to as a constant measurement value (instantaneous value; telemeter value).
[0006]
On the other hand, in the load system, the measurement points are not always provided, and the entire system cannot be monitored quantitatively only by the system information obtained from such a small number of constant measurement points.
[0007]
In such a situation, a power system flow monitoring device that monitors the state of the load system is, for example, described below.
FIG. 7 is a functional block diagram showing an example of the configuration of a conventional power system flow monitoring device 30.
[0008]
The load system power system 1 is the power system of the load system described above, and is a power system in a certain jurisdiction (within the jurisdiction of the power system flow monitoring device 30).
The system state quantity storage unit 31 collects / stores state quantity data of each part of the load power system 1. For example, the load system power supply control center collects data indicating the system status within the jurisdiction (data such as power at the measurement point, current, voltage, etc., and data such as the open / close status of switches such as circuit breakers). Store.
[0009]
The system reliability determination unit 32 determines the reliability of the system based on the state quantity data of each part of the load system power system 1 stored in the system state quantity storage unit 31. Basically, the system reliability is judged by comparing the reference value of the facility reliability of the transmission line, transformer, etc. of the system with the current state quantity. However, this is performed only for a portion having a constant measurement value. If an overload occurs, the operator is notified by an alarm or the like.
[0010]
The HI device 33 is a human interface device (display or the like) that displays the state quantity data stored in the system state quantity storage unit 31, the reliability judgment result of the system (the place where the measured value is always present) by the system reliability judgment unit 32, and the like. ).
[0011]
The reference power flow data storage unit 34 stores reference system state data such as summer peak. For example, in the load system power supply control station, data indicating the state of the power system of a cross section (for example, a tidal current chart at the summer peak) serving as a reference created by past performance data and human estimation is stored.
[0012]
The equipment data storage unit 35 stores equipment data indicating the characteristics of the system equipment and the system connection relation. For example, the constants, names, connection relations between facilities, belonging electric power plant data, and the like of the facilities (lines, buses, transformers, generators, phase adjusting facilities, etc.) constituting the power system are stored.
[0013]
The past record data storage unit 36 stores a time average value (Wh value) of the past end load amount and the like. For example, at a load system power supply control station, past power system state data (telemeter values such as power, current, and voltage at measurement points, switching values of switch values such as circuit breakers, Wh values of terminal loads (integrated values per hour) ), Total demand, weather information, etc.) are stored in a certain period.
[0014]
In the conventional power system power flow monitoring device 30 described above, it is possible to collect state quantity data and determine the reliability of the system and display it for a portion having a constant measurement value in the load power system. In the system power system 1, there are usually few measurement points at all times as described above, and it is impossible to quantitatively grasp the current on the track, the end load, and the like. (Regarding the amount of end load, instead of taking an instantaneous value, measure the Wh value (integrated value per hour) of the distribution transformer load every hour on the hour (24 hours a day from 0:00 to 23:00). , 24 points of data were saved a day). For this reason, the operator or the like is stored in the system state quantity storage unit 31, the reference tidal current data storage unit 34, the equipment data storage unit 35, the past record data storage unit 36, etc., at locations where there are no constantly measured values. Based on the data, qualitatively, the load, the trend of the tidal current, etc. were judged. This may depend on the experience and intuition of the operator, etc., or may be performed by off-line auxiliary calculation.
[0015]
[Problems to be solved by the invention]
As described above, in the conventional power system power flow monitoring method in the load system, since there are few constant measurement points, it is difficult to quantitatively grasp the current in the middle of the line, the end load, etc. It was compensated by qualitatively judging the load, the trend of the current flow, etc., from the information that the operator considered from experience and intuition. Or this was done using off-line auxiliary calculations. In any case, judgment / processing by humans (operators) is necessary.
[0016]
On the other hand, in recent years, the system operation conditions have become complicated due to the increase in demand for load systems and the requirement for high availability of equipment, and the above conventional method increases the burden on the operator and maintains appropriate monitoring and judgment. It's getting harder.
[0017]
An object of the present invention is to realize accurate and quantitative system monitoring without human intervention, particularly in a load power system, and to accurately and objectively grasp future power flow conditions of the entire system. It is to provide a power system power flow monitoring device capable of
[0018]
[Means for Solving the Problems]
The power system power flow monitoring device according to the present invention includes system state data storage means for collecting / storing system state data indicating the power flow state of the power system of the load system, and reference data for storing reference data indicating the system power flow state serving as a reference. Storage means; equipment data storage means for storing equipment data indicating characteristics of system equipment and system connection relation; past record data storage means for storing at least a time average value of each past end load; and the equipment data The reference data stored in the reference data storage means, the time average value of each past end load amount stored in the past record data storage means, and the data collected / stored by the system state data storage means Load estimation means that estimates the instantaneous value of the end load amount using the characteristics of the radial system using the measured value of the wire outlet or the system transformer. When there is a terminal load end in which the time average value of the past terminal load amount is not recorded, the load estimation unit determines the terminal load amount of the terminal load end without the record, the reference data and the system state The estimation is based on the constantly measured values collected / stored by the data storage means.
[0019]
According to the above power system power flow monitoring device, it is possible to estimate the load amount (instantaneous value) at the end, etc., for which measurement values cannot always be obtained, so the current power flow status of the entire system can be grasped accurately and quantitatively and objectively. It becomes possible to do. Furthermore, although the terminal load end has not measured the instantaneous load value, the load Wh value (integrated value for each time) has been measured / saved, but this end does not even measure this Wh value. It can cope with a load end.
[0020]
In the load estimating means, the estimation of the instantaneous value of each end load amount is, for example, calculated by the following formula for an arbitrary radial system,
Pni = ΣPn × Pwi ÷ ΣPwi
(However, Pni: Instantaneous value of the load amount at the i-th terminal load end
Pwi: Time average value of the past load amount at the i-th end load end
ΣPwi: Sum of time average values of past load
ΣPn: Total current load of the radial system)
[0021]
Further, for example, in the load estimation means, as the time average value Pwi of the past load amount at the i-th end load end, for each end load end, the current end load amount of the nearest number of cycles and the same date are similar. A ratio with the end load amount in the time zone may be used as a correction coefficient, and a correction value obtained by multiplying the correction coefficient by the moving average value of the end load amount at the same time as the current time on a similar day may be used. .
[0022]
Thereby, estimation accuracy improves.
In addition, the current measured value of the current power transmission line outlet or the system transformer is used, for example, by taking note of the node information being searched using the node and branch information stored in the facility data storage means. However, it is obtained by searching for a constant measurement point of the supply source to which the end load end is supplied.
[0023]
As a result, the load estimating means can cope with any system state change, and the efficiency is further improved.
The power system flow monitoring device according to the present invention further includes an estimated value storage means for storing an instantaneous value of the end load amount estimated by the load estimation means, and a jurisdiction total stored in the past record data storage means. Load prediction means for predicting the future end load amount based on the continuation data of demand and temperature within a certain period and the data stored in the estimated value storage means;
[0024]
The load prediction means includes a total demand prediction means for predicting the total demand within the jurisdiction from the relationship between the temperature in the nearest continuous period obtained based on the data stored in the past record data storage means and the total demand within the jurisdiction. , Based on the predicted total demand within the jurisdiction determined by the total demand prediction means, the actual total demand on the selected similar day, and the estimated actual end load on the similar day, It consists of prediction means to predict.
[0025]
Thereby, it becomes possible to predict the future end load amount.
The total demand forecasting means, for example, calculates the predicted temperature on the forecast target day based on a linear regression equation indicating the relationship between the temperature on weekdays in the nearest continuous period and the actual value of the total demand within the jurisdiction obtained in advance. A method of obtaining the predicted value of the total demand within the jurisdiction by substituting into the regression formula, and a value obtained by multiplying the temperature difference between the similar date and the forecast target date by the slope of the linear regression formula is used as the actual total demand on the similar date. One of the methods for obtaining the predicted value of the total demand within the jurisdiction by adding is selected and executed according to the characteristics of the forecast date.
[0026]
For example, when the predicted future end load amount exceeds a preset allowable value continuously for a plurality of periods, the load predicting unit is obtained for the actual value and the current time. A ratio with the predicted value that has been calculated is obtained, and the predicted future end load amount is corrected using the ratio.
[0027]
Thus, even when the predicted value and the actual value are greatly different due to some cause, the predicted value can be corrected, and the prediction accuracy can be improved.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing an example of the configuration of a power system flow monitoring device 10 according to the present embodiment. In the figure, components that are substantially the same as those of the conventional power system flow monitoring device 30 are given the same reference numerals, and detailed descriptions thereof are omitted.
[0029]
In the figure, the load estimation unit 11 is a radial system based on various data stored in the system state quantity storage unit 31, the reference power flow data storage unit 34, the equipment data storage unit 35, and the past record data storage unit 36. The current end load amount (instantaneous value) is estimated using the characteristics of. The processing of the load estimation unit 11 will be described in detail later with reference to FIG.
[0030]
The estimated value storage unit 12 accumulates / stores the current end load amount (instantaneous value) estimated by the load estimation unit 11 for a certain period.
The load predicting unit 13 predicts the future end load amount (that day, the next day) based on the estimation result obtained by the load estimating unit 11 and the data stored in the past record data storage unit 36. The “future” is not limited to the next day, but the next day is appropriate up to the next day if the accuracy of the prediction is taken into consideration from the relationship of the accuracy such as the predicted temperature described later.
[0031]
The predicted value storage unit 14 stores the predicted value of the end load amount predicted by the load predicting unit. The process of the predicted value storage unit 14 will be described in detail later with reference to FIG. Based on the data stored in the system state quantity storage unit 31 and the predicted value storage unit 14 and the current end load amount (instantaneous value) estimated by the load estimation unit 11, the tidal current calculation unit 15 Calculate future tidal conditions. This is performed by, for example, a known DC method power flow calculation method.
[0032]
The system reliability determination unit 16 basically has substantially the same function as the conventional system reliability determination unit 32, but the system reliability determination unit 32 always makes a determination based only on the measured value. For this reason, since the entire target system could not be monitored, it can be determined including the estimation result by the load estimator 11 and so on, so that the reliability of the entire target system can be determined. Furthermore, by determining based on the load prediction result, it is possible to determine the reliability of the entire future target system.
[0033]
Below, the load estimation method in the load estimation part 11 is demonstrated in detail first.
As described above, the load estimation unit 11 estimates the current current end load amount (instantaneous value) using the characteristics of the radial system. This is because of the strong correlation between the power flow at the inlet of the radial system (transmission line outlet or secondary side of the system transformer) and each end load in the radial system. Each end load is estimated by a method of calculating each end load from the inlet flow (end load source).
[0034]
That is, the total load value of a certain radial system (partial system) can be obtained by the following equation (1) when the loss of active power is ignored.
ΣPn = ΣPi−ΣPo + ΣPg (1)
(ΣPn: Total current load value of the subsystem
ΣPi: active power total value flowing into the partial system
ΣPo: Active power total value flowing out from the partial system
ΣPg; active power total value generated in the partial system)
Then, each end load amount can be estimated by the following equation (2) from the load amount total value of the partial system obtained by the above equation (1).
[0035]
Pni = ΣPn × Pwi ÷ ΣPwi (2)
(Pni: load amount at the i-th end load end (end load amount; instantaneous value)
Pwi: Time average value (Wh value) of the past load amount at the i-th end load end
ΣPwi: Sum of time average value (Wh value) of past load)
The terminal load amount estimation processing by the load estimation unit 11 using these equations (1) and (2) will be described below.
[0036]
FIG. 2 is a flowchart showing the end load amount estimation processing by the load estimation unit 11 of FIG.
In the figure, first, the load at the end load end having no actual load value (Wh value) based on the data stored in the system state quantity storage unit 31, the reference power flow data storage unit 34, and the facility data storage unit 35. Estimation is performed (step S1). As described above, although the terminal load end has not measured the instantaneous load value as described above, the load Wh value (integrated value for each time) has been measured / saved, but this load (Wh This is a process considering that there is a terminal load end for which (value) is not measured.
[0037]
That is, while referring to the equipment data stored in the equipment data storage unit 35, reference system state data (reference current, reference load data) such as summer peak stored in the data reference current data storage unit 34, and Based on the current power flow data (telemeter value) of the current system transformer collected / stored in the system state quantity storage unit 31, the terminal load end having no actual load value (Wh value) is obtained by the following equation (3): And so on.
[0038]

(However, P ′; the reference load at the load end stored in the reference flow data storage unit 34)
Next, the similar day Wh value is corrected (step S2).
[0039]
This calculates | requires the said Pwi, ie, the time average value (Wh) of the past load amount of each terminal load end, by the correction calculation of the following (4) Formula which used the similar day Wh value.
[Expression 1]

Note that the above-mentioned “front-rear moving average value” means that the active power (Wh) at the present time (for example, 3:00) is P2, and the current time before and after (meaning 0 minutes on the hour), that is, the previous hour (2: 00), when the active power (Wh) at the later hour (4:00) is P1 and P3, respectively, the forward / backward moving average value = (P1 + P2 + P3) / 3.
[0040]
In addition, the end load actual value (time average value (Wh value) of each past end load amount) stored in the past record data storage unit 36 is used to calculate the correction coefficient K.
[0041]
Next, the load sum (Wh value) of each radial system is calculated based on the data stored in the reference power flow data storage unit 34, the facility data storage unit 35, and the past record data storage unit 36 (step S3). .
[0042]
This is based on the time average value (Wh value) of each end load corrected in step S2 above, and finds the total power flow value (Wh value) of the outlet transmission line (or system transformer) for each radial system. The total tidal current value is referred to as ΣPwi (the sum of the time average values (Wh) of past loads).
[0043]
Then, based on the data stored in the system state quantity storage unit 31 and the equipment data storage unit 35, an automatic search for the supply source of the end load is performed (step S4).
This searches for the constantly measured value (telemeter value; TM) of the transmission line outlet to which each load end is supplied or the system transformer, and calculates this telemeter value as the total value ΣPn of the current load amount of the radial system. To do. The process of step S4 will be described in detail later with reference to FIG.
[0044]
Since ΣPn, Pwi, and ΣPwi are obtained by the processes in steps S1 to S4, the load of each end (instantaneous value) can be estimated and calculated by executing the calculation of the above equation (2) (step S5). ).
[0045]
FIG. 3 is a flowchart for explaining in detail the process for automatically searching for the end load supply source, which is the process in step S4 of FIG.
In the figure, first, the node and branch information stored in the equipment data storage unit 35 and the system state collected / stored by the system state quantity storage unit 31 are read (step S11).
[0046]
Then, the following steps S13 to S18 are repeatedly executed by the number of load ends (step S12).
That is, first, it is determined whether or not the load end to be processed in the loop process has already been searched (step S13). If the search has been completed (step S13, YES), the process proceeds to the next loop process.
[0047]
If the search has not been completed (NO in step S13), each branch that flows into the load end is checked, and a branch with a measurement point is taken out (step S14), and a measuring device is actually installed therein. It is determined whether or not (implementation) (step S15).
[0048]
If the measurement point is actually equipped with a measurement device (step S15, YES), the measurement point is regarded as the power supply source of the radial system (step S16).
[0049]
When the measuring device is not equipped (step S15, NO), the other end node of the branch having the maximum power flow is taken out (step S17), and this is taken on the search path (from each end load end to the transmission line outlet port or The node information on the route to the system transformer is recorded (step S18).
[0050]
Thereafter, the processes in steps S13 to S18 are repeated for the number of load ends. At that time, the node information noted above is referred to and used.
FIG. 4 is a flowchart for explaining end load amount prediction processing by the load prediction unit 13.
[0051]
In the figure, first, the total demand within the jurisdiction is predicted (step S21).
This is the following linear regression equation that approximates the relationship between the temperature (maximum temperature or minimum temperature) and the total demand in the jurisdiction only for weekdays in the last consecutive period (for example, 2 weeks). (5) and (6) are obtained for each time zone (for example, every hour).
<Linear regression equation 1>
Total demand within the jurisdiction _t = A _t × Maximum temperature + b _t (T = 1-24) (5)
<Linear regression equation 2>
Total demand within the jurisdiction _t = C _t × Minimum temperature + d _t (T = 1-24) (6)
And according to the demand characteristic of a forecast day, either of the following four forecast formulas (7)-(10) is selected / used, and the total demand forecast value of each time slot | zone is calculated. At this time, which prediction formula is selected is determined according to data set in advance by the day type and time zone of the forecast day so that the accuracy is improved in accordance with the fluctuation characteristics of the in-jurisdiction demand. In addition, these forecast formulas use the forecast temperature of the forecast target day, and the actual demand and temperature of the similar day, but also when to make the similar day (the previous day, the previous week, any designated day, etc.) The determination is made according to the data set by the operator in advance for each day type or forecast date.
<Prediction formula 1>

<Prediction formula 2>

<Prediction formula 3>
Predicted total demand within jurisdiction _t = A _t × Expected maximum temperature + b _t (T = 1-24) (9)
<Prediction formula 4>
Predicted total demand within jurisdiction _t = C _t × Expected minimum temperature + d _t (T = 1-24) (10)
In the above method, the linear regression equation is obtained in advance based on data only on weekdays, but the prediction target day is not limited to weekdays. Saturdays, Sundays, and holidays have different demands from weekdays, but tend to change almost in parallel (with the same slope) as the linear regression equation created based on the weekday data. Thus, for Saturdays, Sundays, and holidays, if a formula that predicts using the similar day results and the slope of the regression formula is used, as in <Prediction Formula 1> and <Prediction Formula 2>, demand _t Can be requested.
[0052]
After predicting the total demand within the jurisdiction through the process of step S21, each terminal load amount (instantaneous value) is predicted (step S22).
This is because the predicted total demand amount within the jurisdiction obtained by the processing of step S21 and the end load amount (instantaneous value) estimated by the load estimation unit 11 and accumulated in the estimated value storage unit 12 in the past (hereinafter, estimated results). Each terminal load amount (instantaneous value) is predicted and calculated using the following equation (11). At that time, the estimated actual end load amount is the one on the similar date, but when the similar date is to be used (the previous day, the previous week, any day, etc.), the operator etc. sets in advance the day of the week type or the forecast date individually. Judge according to the data.
[0053]

(Time at 60 / n minute interval from t = 1 to 24, tn = 00: 00 to 23:59)
Here, t = 1 is used for the n point from tn = 00: 00 to 00:59
Use t = 2 for n points between tn = 01: 00 and 01:59
・ ・ ・ ・ ・ ・
For n point from tn = 23: 00 to 23:59, use t = 24
Finally, the end load amount (instantaneous value) is corrected (step S23).
[0054]
This is because the error between the predicted value for the past N cycles from the current predicted time and the actual value is compared with a preset allowable value (m% of the actual value), and according to this comparison result. Make the following corrections.
(A) When the allowable value is exceeded continuously (in the same direction)
The terminal predicted load amount at each time in the future (for today) is corrected according to the ratio between the actual value at the current predicted time and the predicted value. That is, the correction value tn of the terminal predicted load amount is obtained by the following equation (12).
[0055]
Correction value tn = (actual value at current time / predicted value at current time) × predicted value tn (12)
(B) In cases other than (a) above
Do not correct
Furthermore, in order to flexibly cope with a sudden change, a gradual change, etc., a plurality of combinations of monitoring periods and allowable values can be defined, and correction may be made accordingly. If this method is used, for example, the correction can be performed with a relatively short period when the change is abrupt, and the correction can be performed with a relatively long period when the change is gradual.
[0056]
FIG. 5 is a diagram illustrating an example of a hardware configuration of an information processing device that implements the power system flow monitoring device of the present invention.
In the figure, the information processing apparatus 20 includes a CPU 21, a storage unit 22 (including a portable storage medium 22a), a memory 23, an input / output interface unit 24, and the like.
[0057]
The CPU 21 is a central processing unit that controls the entire information processing apparatus 20.
The storage unit 22 is a storage device such as an HDD in which a program for realizing at least the function of the power system flow monitoring device of the present invention described above is stored. Alternatively, the storage unit 22 may be a combination of the portable storage medium 22a and its drive reading device (for example, a floppy disk (FD) and a floppy disk drive (FDD)). In addition to the FD, the portable storage medium 22a includes a CD-ROM, a memory card, a DVD, an MO, and the like.
[0058]
The memory 23 is a RAM or the like for temporarily storing the program stored in the storage unit 22 and causing the CPU 21 to execute the program. The memory 23 also has a storage area for temporarily storing various data (intermediate result data and the like) generated while the CPU 21 is executing the program.
[0059]
The input / output interface unit 24 is an input / output interface connected to an external network or the like so that the above-described system state quantity storage unit 31 collects each state quantity of the power system 1.
[0060]
Further, although not particularly illustrated, a display, a keyboard, or the like may be provided.
The present invention is not limited to the power system power flow monitoring device itself, and when used by a computer, a computer-readable recording medium storing a program for realizing the functions of the above-described embodiments of the present invention ( Storage medium).
[0061]
【The invention's effect】
As described above in detail, according to the power system power flow monitoring device of the present invention, it is possible to estimate the end load amount or the like that cannot always be measured in the monitoring of the load power system. Quantitative automatic monitoring of all power lines in the power system is possible. Furthermore, it is possible to predict the state of the future system, which contributes to improvement of the accuracy and efficiency of system monitoring.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating an example of a configuration of a power system power flow monitoring device according to an embodiment.
FIG. 2 is a flowchart for explaining a terminal load amount estimating method;
FIG. 3 is a flowchart for explaining in detail processing for automatically searching for a terminal load supply source;
FIG. 4 is a flowchart for explaining end load amount prediction processing;
FIG. 5 is a diagram illustrating an example of a hardware configuration of an information processing device that realizes a power system flow monitoring device.
FIG. 6 is a conceptual diagram showing an example of a power system.
FIG. 7 is a functional block diagram showing an example of the configuration of a conventional power system power flow monitoring device.
[Explanation of symbols]
10 Power system power flow monitoring device
11 Load estimation unit
12 Estimated value storage
13 Load prediction section
14 Predicted value storage
15 Tidal current calculator
16 System reliability judgment part
31 System state quantity storage
34 Reference current data storage
35 Equipment data storage
36 Past record data storage
20 Information processing device
21 CPU
22 Memory unit
22a Portable storage medium
23 memory
24 I / O interface section

Claims (11)

System state data storage means for collecting / storing system state data indicating the power flow state of the load system power system;
Reference data storage means for storing reference data indicating a system power flow state as a reference;
Facility data storage means for storing facility data indicating characteristics of system facilities and system connection relations;
Past record data storage means for storing at least a time average value of each past end load,
Collected by the facility data, the reference data stored in the reference data storage means, the time average value of each past end load amount stored in the past record data storage means, and the system state data storage means A load estimation means for estimating the instantaneous value of the end load amount using the characteristics of the radial system using the transmission line outlet to store or the constantly measured value of the system transformer,
When there is a terminal load end in which the time average value of the past terminal load amount is not recorded, the load estimation unit determines the terminal load amount of the terminal load end without the record, the reference data and the system state An electric power system power flow monitoring device that estimates based on the constantly measured values collected / stored by a data storage means . In the load estimation means, the estimation of the instantaneous value of each end load amount is calculated by the following formula for an arbitrary radial system,
P ni = ΣP n × P wi ÷ ΣP wi
(However, P ni ; Instantaneous value of the load amount at the i-th end load end
P wi ; Time average value of past load amount at the i-th end load end
ΣP wi ; Sum of time average values of past loads
ΣP n ; Total load value of the radial system)
The power system power flow monitoring device according to claim 1. In the load estimation means, as the time average value P wi of the past load amount at the i-th end load end , for each end load end, the current end load amount of the nearest several cycles and the same time zone of the similar day 3. The correction value obtained by multiplying the correction coefficient by a ratio with the end load amount and multiplying the correction coefficient by the front-rear moving average value of the end load amount at the same time on a similar day is used. The power system power flow monitoring device described. The current measured value of the current power transmission line outlet or the system transformer is the end load, while using the node and branch information stored in the facility data storage means and taking note of the node information during the search. determined by searching constantly measuring point sources which ends are supplied, according to claim 2, characterized in that the continuously measured values obtained the current load sum value .SIGMA.P n of the radial line Power system power flow monitoring device. The reference data includes reference load data and reference load data at the end load end without the record, and the arbitrary radial system is connected to the main system by an arbitrary system transformer,
In the load estimation means, the end load amount at the end load end without the record is calculated by the following equation.
End load = (Current system transformer ΣP (telemeter value))
÷ (ΣP of the reference power flow data of the transformer in question) × P '
(However, P '; Reference load data at the end load end without the above record)
The power system power flow monitoring device according to claim 1. Estimated value storage means for storing an instantaneous value of the end load amount estimated by the load estimation means;
Load prediction means for predicting the future end load amount based on the total demand within the jurisdiction stored in the past record data storage means, the continuation data for a certain period of temperature, and the data stored in the estimated value storage means When,
The power system flow monitoring device according to claim 1, further comprising: The load forecasting means is a total demand forecasting means for forecasting the total demand in the jurisdiction from the relationship between the temperature in the nearest continuous period obtained based on the data stored in the past record data storage means and the total demand in the jurisdiction. , Based on the predicted total demand in the jurisdiction determined by the total demand forecasting means, the actual total demand on the selected similar day, and the estimated actual end load on the similar day, 7. The power system power flow monitoring device according to claim 6 , further comprising prediction means for predicting. The total demand forecasting means is based on a linear regression equation indicating the relationship between the temperature on weekdays in the nearest continuous period and the actual value of the total demand within the jurisdiction obtained in advance, and the predicted temperature on the forecast target day is expressed by the linear regression equation. Substituting into a method for obtaining a predicted value of the total demand within the jurisdiction, and adding a value obtained by multiplying the temperature difference between the similar date and the prediction target date by the slope of the linear regression equation to the actual total demand on the similar date 8. The power system power flow monitoring device according to claim 7, wherein one of the methods for obtaining the predicted value of the total demand within the jurisdiction is selected and executed according to the characteristic of the predicted date. The load predicting means has been obtained for the actual value and the current time when the predicted future end load amount exceeds a preset allowable value continuously for a plurality of periods. 8. The power system power flow monitoring device according to claim 7 , wherein a ratio with a predicted value is obtained, and the predicted future end load amount is corrected using the ratio. Optionally leave further store actual values for the specified day, the load prediction means, claim the optional day also characterized in that to predict similar date regarded to future each end load 6 Or the electric power system power flow monitoring apparatus of 7 . Predicted value storage means for storing a future end load amount predicted by the load prediction means;
Based on the system state data stored in the system state data storage means, the future end load amount stored in the predicted value storage means, and the instantaneous value of the end load amount estimated by the load estimation means, Tidal current calculation means for calculating current or future tidal current conditions;
Reliability determination monitoring means for determining the reliability of the power system based on the current or future power flow status calculated by the power flow calculation means;
The power system power flow monitoring device according to claim 6 , further comprising:

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