JP2006333575A

JP2006333575A - Power supply shut-down detection device and power supply shut-down amount calculation device

Info

Publication number: JP2006333575A
Application number: JP2005150870A
Authority: JP
Inventors: Yasuyuki Kowada; 靖之小和田; Takashi Sasaki; 孝志佐々木
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2005-05-24
Filing date: 2005-05-24
Publication date: 2006-12-07

Abstract

PROBLEM TO BE SOLVED: To provide a power supply shut-down detection device and a power supply shut-down amount calculation device that can detect power supply shut-down and calculate a power supply shut-down amount, by using an effective power flow at a connecting point with the other power system and the information of a frequency. SOLUTION: The effective power flow Pi that flows in and out at the connecting point of an own power system and the other power system is measured and collected to an information accumulation means 11 via an information transmission means 4. An effective power flow addition means 12 calculates the sum PT=ΣPi of the effective power flow Pi that flows in and out between the other system and the own system. A difference calculation means 14 calculates a difference DP between the sum PT(t) of the calculated newest effective power flow and the sum PT(t▵-t) of the effective power flow that is calculated a fixed time (▵t) before. A power supply shut-down determination means 16 compares the difference DP of the sum of the effective power flow and a prescribed threshold DP_limit, determines that there arises the power supply shut-down when the difference DP is not smaller than the prescribed threshold, and detects the power supply shut-down in the own power system. COPYRIGHT: (C)2007,JPO&INPIT

Description

この発明は、例えば電力系統の安定度を維持する系統安定化装置に用いられる電源脱落検出装置及び電源脱落量算出装置に係わり、特に比較的少ない情報に基づき動作可能な電源脱落検出装置及び電源脱落量算出装置に関するものである。 The present invention relates to a power loss detection device and a power loss amount calculation device used in, for example, a power system stabilization device that maintains the stability of a power system, and more particularly to a power loss detection device and a power loss that are operable based on relatively little information. The present invention relates to a quantity calculation device.

従来、電源脱落検出や電源脱落量算出は、発電所近傍もしくは発電所と基幹系統とを結ぶ電源線に何らかの計測端末を設置し、電源脱落発生前の有効電力潮流を把握しておくとともに、電源脱落発生時には、電源脱落の事象そのものを捉えて検出し、事前と事後の有効電力潮流の差を電源脱落量として算出する方法が一般的である（例えば、特許文献１参照）。 Conventionally, power loss detection and power loss amount calculation have been done by installing a measurement terminal near the power plant or on the power line connecting the power plant and the main system, and grasping the active power flow before the power loss occurs. In general, when a power loss occurs, a method of detecting and detecting the power loss event itself and calculating the difference between the previous and subsequent active power flows as the power loss amount is common (see, for example, Patent Document 1).

特開平１１−２３４９０４号公報（第３頁右欄第２６〜第２７行目、同第４６行目〜第４９行目、第４頁第（２）式及び図１）。JP-A-11-234904 (right column on page 3, lines 26-27, lines 46-49, page 4, expression (2) and FIG. 1).

従来の電源脱落検出は、上述のように電源脱落が生じうる箇所にあらかじめ何らかの計測端末を設置し、この情報に基づき判断を実施していた。この方法は確実に検出が行える反面、電源脱落を検出すべき全ての箇所に計測端末を備える必要があり、システムが大規模化するという欠点があった。また、状況変化により電源脱落を検出すべき箇所は変化する可能性があるが、その度に計測端末の新設や撤去を行う必要があり、システム維持に手間がかかるという問題点があった。
この発明は、上記のような問題点を解決するためになされたものであり、比較的少ない情報量に基づいて、具体的には他の電力系統との連系点における有効電力潮流や周波数の情報に基づいて、電源脱落検出及び電源脱落量算出が可能な電源脱落検出装置及び電源脱落量算出装置を得ることを目的とする。 In the conventional power-off detection, as described above, some measurement terminal is installed in advance at a place where the power-off may occur, and a determination is made based on this information. While this method can reliably detect, it is necessary to provide measurement terminals at all locations where power loss should be detected, and there is a drawback that the system becomes large-scale. In addition, the location where the power loss should be detected may change depending on the situation change. However, it is necessary to newly install or remove the measurement terminal each time, and there is a problem that it takes time to maintain the system.
The present invention has been made to solve the above-described problems, and based on a relatively small amount of information, specifically, the effective power flow and frequency at a connection point with another power system. It is an object of the present invention to provide a power-off detection device and a power-off-amount calculation device capable of detecting a power-off and calculating a power-off amount based on information.

この発明に係る電源脱落検出装置においては、自己の電力系統と他の電力系統との連系点を通過する有効電力潮流に基づいて自己の電力系統内における電源脱落の有無を判定するものである。 In the power supply loss detection device according to the present invention, the presence or absence of power supply loss in the own power system is determined based on the active power flow passing through the connection point between the own power system and another power system. .

また、この発明に係る電源脱落量算出装置においては、自己の電力系統と他の電力系統との連系点を通過する有効電力潮流の和を算出する有効電力潮流加算手段と連系点における周波数の時間微分値を求める周波数時間微分値算出手段とを有し有効電力潮流の和と周波数の時間微分値とに基づいて自己の電力系統内における需給アンバランス量を算出する需給アンバランス量算出手段と、需給アンバランス量に基づいて自己の電力系統内に発生した電源脱落量を求める電源脱落量算出手段とを備えたものである。 Further, in the power supply loss amount calculating device according to the present invention, the active power flow adding means for calculating the sum of the active power flows passing through the connection point between the own power system and the other power system and the frequency at the connection point Supply / demand imbalance amount calculating means for calculating a supply / demand unbalance amount in its own power system based on the sum of the active power flow and the time differential value of the frequency And a power supply loss amount calculating means for obtaining a power supply loss amount generated in the own power system based on the supply and demand imbalance amount.

この発明の電源脱落検出装置においては、自己の電力系統と他の電力系統との連系点を通過する有効電力潮流に基づいて自己の電力系統内における電源脱落の有無を判定するものであるので、他の電力系統との連系点における有効電力潮流の情報を用いて、容易に電源脱落を検出することができる。 In the power supply loss detection device of the present invention, the presence or absence of power supply loss in the own power system is determined based on the effective power flow passing through the connection point between the own power system and another power system. The power loss can be easily detected by using the information of the active power flow at the connection point with other power systems.

また、この発明の電源脱落量算出装置においては、自己の電力系統と他の電力系統との連系点を通過する有効電力潮流の和を算出する有効電力潮流加算手段と連系点における周波数の時間微分値を求める周波数時間微分値算出手段とを有し有効電力潮流の和と周波数の時間微分値とに基づいて自己の電力系統内における需給アンバランス量を算出する需給アンバランス量算出手段と、需給アンバランス量に基づいて自己の電力系統内に発生した電源脱落量を求める電源脱落量算出手段とを備えたので、他の電力系統との連系点における電気的量の情報を用いて、容易に電源脱落量を求めることができる。 Further, in the power supply dropout amount calculating device of the present invention, the active power flow adding means for calculating the sum of the active power flows passing through the connection point between the own power system and the other power system and the frequency at the connection point are calculated. A supply-demand imbalance amount calculating means for calculating a supply-demand unbalance amount in its own power system based on the sum of the active power flow and the time-differential value of the frequency. And a power supply loss amount calculating means for determining the power supply loss amount generated in the own power system based on the supply and demand imbalance amount, so that information on the electrical quantity at the connection point with other power systems is used. The amount of power loss can be easily determined.

実施の形態１．
図１〜図３は、この発明を実施するための実施の形態１を示すものであり、図１は全体系統を示す系統図、図２は電源脱落検出装置の構成を示す構成図、図３は電源脱落検出装置の動作を示すフローチャートである。図１において、電源脱落検出装置１０が自社系統１００内に設けられている。自社系統１００は発電機１１１や送電線１２１を有し、同様に図示しない発電機や送電線を有する他社系統２００，３００と連系点Ｇ１〜Ｇ４を介して接続された連系線４０１〜４０４にて連系されている。 Embodiment 1 FIG.
1 to 3 show a first embodiment for carrying out the present invention. FIG. 1 is a system diagram showing an entire system, FIG. 2 is a configuration diagram showing a configuration of a power loss detection device, and FIG. These are flowcharts which show operation | movement of a power-off detection apparatus. In FIG. 1, a power loss detection device 10 is provided in the company system 100. The in-house system 100 includes a generator 111 and a power transmission line 121. Similarly, connection lines 401 to 404 connected to other company systems 200 and 300 having a generator and a transmission line (not shown) via connection points G1 to G4. It is connected with.

自社系統１００内には、図２に示すように、連系点Ｇ１〜Ｇ４を通過する有効電力を計測する電力計測手段２と、計測した情報を伝送するための情報伝送手段４と、電源脱落検出装置１０とが設けられている。電源脱落検出装置１０は、伝送された情報を蓄積する情報蓄積手段１１と、蓄積した情報を基に有効電力潮流の和を算出する有効電力潮流加算手段１２と、有効電力潮流の和の差分を算出する差分算出手段１４と、電源脱落の有無を判定する差分ベース電源脱落判定手段としての電源脱落判定手段１６とを備えている。なお、装置としては、例えば電源脱落検出装置１０の機能を通常用いられている系統安定化システムの中央装置に持たせる。 In the in-house system 100, as shown in FIG. 2, the power measuring means 2 for measuring the active power passing through the connection points G1 to G4, the information transmitting means 4 for transmitting the measured information, and the power disconnection A detection device 10 is provided. The power loss detection device 10 includes an information storage unit 11 that stores the transmitted information, an active power flow addition unit 12 that calculates the sum of the active power flows based on the stored information, and a difference between the sums of the active power flows. Difference calculating means 14 for calculating and power supply loss determining means 16 as difference base power supply loss determining means for determining presence / absence of power supply loss are provided. As the device, for example, the function of the power-off detection device 10 is provided in the central device of the system stabilization system that is normally used.

次に、図３のフローチャートに従って動作を説明する。
ステップＳ１１では、連系線４０１〜４０４において、自社系統と他社系統との間で出入する有効電力潮流（Ｐｉ、但しｉは各連系点を意味する）を電力計測手段２にて計測し、計測値を情報伝送手段４を介して情報蓄積手段１１に収集し蓄積する。有効電力の計測は、例えば連系点が４カ所ある場合、図１に示す通り連系点Ｇｌ〜Ｇ４にて計測することになる。
ステップＳ１２では、有効電力潮流加算手段１２が、収集された有効電力潮流（Ｐｉ）を基に、自社系統と他社系統との間を流出入する有効電力潮流の和ＰＴを、次の（１）式により算出する。
ＰＴ＝ΣＰｉ（１）
この値は、計測時間毎に蓄積する。 Next, the operation will be described with reference to the flowchart of FIG.
In step S11, the power measuring means 2 measures the active power flow (Pi, where i means each interconnection point) entering and exiting between the company system and the other company system in the interconnection lines 401 to 404, Measurement values are collected and stored in the information storage means 11 via the information transmission means 4. For example, when there are four interconnection points, the active power is measured at the interconnection points G1 to G4 as shown in FIG.
In step S12, the active power flow adding means 12 calculates the sum PT of the active power flows flowing in and out between the own system and the other company's system based on the collected active power flow (Pi) as the following (1). Calculate by the formula.
PT = ΣPi (1)
This value is accumulated every measurement time.

ステップＳ１３では、差分算出手段１４が、ステップＳ１２において算出された最新の有効電力潮流の和ＰＴ（ｔ）と、一定時間（△ｔ）前に算出した有効電力潮流の和ＰＴ（ｔ−△ｔ）との差分ＤＰを、次の（２）式により算出する。
ＤＰ＝ＰＴ（ｔ）−ＰＴ（ｔ一△ｔ）（２）
ステップＳ１４では、電源脱落判定手段１６が、ステップＳ１３で算出した有効電力潮流の和の差分ＤＰと所定の閾値ＤＰ＿ｌｉｍｉｔを比較する。そして、次の（３）式に従って、差分ＤＰが所定の閾値ＤＰ＿ｌｉｍｉｔ以上のときステップＳ１５へ進み、電源脱落の有りと判定して処理を終了する。
ＤＰ≧ＤＰ＿ｌｉｍｉｔ：電源脱落あり
ＤＰ＜ＤＰ＿ｌｉｍｉｔ：電源脱落なし（３）
ステップＳ１４において差分ＤＰが所定値未満と判定された場合は電源脱落なしと判定し、ステップＳ１１に戻る。
なお、計測誤差の影響を軽減するため、上記のステップＳ１４における差分ＤＰが所定値以上との判定が一定回数連続した場合に初めてステップＳ１５に進むようにしてもよい。 In step S13, the difference calculation means 14 calculates the sum PT (t) of the latest active power flow calculated in step S12 and the sum PT (t−Δt) of the active power flow calculated before a certain time (Δt). ) Is calculated by the following equation (2).
DP = PT (t) −PT (t−1Δt) (2)
In step S14, the power loss determination unit 16 compares the difference DP of the sum of the active power flows calculated in step S13 with a predetermined threshold value DP_limit. Then, according to the following equation (3), when the difference DP is equal to or larger than the predetermined threshold value DP_limit, the process proceeds to step S15, and it is determined that there is a power loss and the process is terminated.
DP ≧ DP_limit: Power supply is disconnected DP <DP_limit: Power supply is not disconnected (3)
If it is determined in step S14 that the difference DP is less than the predetermined value, it is determined that there is no power loss and the process returns to step S11.
In order to reduce the influence of the measurement error, the process may proceed to step S15 for the first time when the determination that the difference DP in step S14 is equal to or greater than a predetermined value continues for a certain number of times.

以上のように、この発明の実施の形態１によれば、電源脱落が発生しうる箇所の全てに電力計測手段を備えなくても、他の電力系統との連系点における有効電力潮流の情報を用いることで、容易に電源脱落を検出することが可能となる。 As described above, according to the first embodiment of the present invention, the information on the effective power flow at the connection point with another power system can be provided without providing the power measuring means in all the places where the power loss can occur. By using this, it is possible to easily detect power loss.

実施の形態２．
実施の形態１では、電源脱落発生の判定に流入有効電力の和ＰＴの差分（変化幅）ＤＰ（上記（２）式参照）を用いている。この変化幅ＤＰの値は電源脱落発生時には確実に増加するが、一定の時間遅れが存在する。このため、電源脱落の程度、あるいは閾値の設定によっては、検出タイミングが遅れる可能性がある。そこで、この実施の形態２では、他の電気的量の情報も併せて演算を実施し、自社系統の需給アンバランス量を算出することにより、検出の高速化、高精度化を図るものである。図４、図５は、この発明の実施の形態２を示すものであり、図４は電源脱落検出装置の構成を示す構成図、図５は電源脱落検出装置の動作を示すフローチャートである。 Embodiment 2. FIG.
In the first embodiment, the difference (change width) DP (see the above formula (2)) of the sum PT of the inflow active power is used for the determination of the occurrence of the power loss. Although the value of the change width DP is surely increased when the power is cut off, there is a certain time delay. For this reason, the detection timing may be delayed depending on the degree of power loss or the setting of a threshold value. Therefore, in the second embodiment, calculation is performed together with other electrical quantity information, and the supply / demand imbalance amount of the in-house system is calculated, thereby speeding up detection and increasing accuracy. . 4 and 5 show the second embodiment of the present invention. FIG. 4 is a block diagram showing the configuration of the power loss detection device, and FIG. 5 is a flowchart showing the operation of the power loss detection device.

図４において、周波数計測手段６が設けられ、情報伝送手段４を介して連系点Ｇ１〜Ｇ４における周波数情報が電源脱落検出装置２０へ送られる。電源脱落検出装置２０は、周波数時間微分値算出手段２１、需給アンバランス量算出手段２４、需給アンバランス量ベース電源脱落判定手段としての電源脱落判定手段２６を有する。その他の構成については、図１に示した実施の形態１と同様のものであるので、相当するものに同じ符号を付して説明を省略する。 In FIG. 4, a frequency measurement unit 6 is provided, and frequency information at the connection points G 1 to G 4 is sent to the power supply loss detection device 20 via the information transmission unit 4. The power loss detection device 20 has a frequency time differential value calculation means 21, a supply / demand imbalance amount calculation means 24, and a power supply loss determination means 26 as a supply / demand unbalance amount base power supply loss determination means. Since other configurations are the same as those of the first embodiment shown in FIG. 1, the same reference numerals are given to the corresponding components and the description thereof is omitted.

次に、図５のフローチャートに従って動作を説明する。
ステップＳ２１では、連系点Ｇ１〜Ｇ４を他社系統側と自社系統側との間で出入りする有効電力潮流Ｐｉの計測値及び各地点の周波数Ｆｉの計測値を、電力計測手段２及び周波数計測手段６にて収集し、情報蓄積手段１１に収集、蓄積する。 Next, the operation will be described with reference to the flowchart of FIG.
In step S21, the measured value of the active power flow Pi and the measured value of the frequency Fi at each point between the other company's system side and the company's system side at the interconnection points G1 to G4, the power measurement unit 2 and the frequency measurement unit 6 and collected and stored in the information storage means 11.

ステップＳ２２では、有効電力潮流加算手段１２が、収集された有効電力潮流（Ｐｉ）を基に、自社系統と他社系統との間を流出入する有効電力潮流の和ＰＴを、次の（４）式により算出する。
ＰＴ＝ΣＰｉ（４）
また、ステップＳ２３において、周波数時間微分値算出手段２１が、収集された周波数（Ｆｉ）の値を基に、演算に用いる周波数Ｆを次の（５）式により算出する。
Ｆ＝（ΣＦｉ）／ｎ（５）
但し、ｎ：計測周波数点数
なお、周波数Ｆについては、有効電力潮流の和ＰＴと時間が揃うならば、別途自社系統内で計測、算出した値を用いてもよい。
次に、周波数Ｆを時間について微分して、周波数時間微分値ｄＦ（ｔ）／ｄｔを求める。 In step S22, the active power flow adding means 12 calculates the sum PT of the active power flow flowing in and out between the own system and the other company's system based on the collected effective power flow (Pi) as the following (4). Calculate by the formula.
PT = ΣPi (4)
Further, in step S23, the frequency time differential value calculating means 21 calculates the frequency F used for the calculation by the following equation (5) based on the collected frequency (Fi) value.
F = (ΣFi) / n (5)
However, n: number of measurement frequency points As for the frequency F, if the time and the sum PT of the active power flow are equal, a value measured and calculated separately in the own system may be used.
Next, the frequency F is differentiated with respect to time to obtain a frequency time differential value dF (t) / dt.

ステップＳ２４では、需給アンバランス量算出手段２４が、ステップＳ２２，Ｓ２３にて算出した有効電力潮流の和ＰＴ、周波数時間微分値ｄＦ（ｔ）／ｄｔの値を基に、需給アンバランス量△Ｐを次の（６）式により算出する。
△Ｐ＝△ＰＴ（ｔ）−（Ｍ／Ｆ０）・ｄＦ（ｔ）／ｄｔ
△ＰＴ（ｔ）＝ＰＴ（ｔ）−ＰＴ０（６）
但し、
Ｍ：慣性定数（ｓ）
ＰＴ０：電源脱落発生前の他社系統と自社系統との間で流出入する有効電力潮流の和
Ｆ０：基準周波数（Ｈｚ）
Ｆ：計測周波数（Ｈｚ）
ここで、慣性定数Ｍの値は、別途オンラインで設定するものとする。このようにして算出される需給アンバランス量△Ｐは、電源脱落発生と同時に大きく変化することから、高速な検出が期待できる。 In step S24, the supply / demand imbalance amount calculation means 24 calculates the supply / demand imbalance amount ΔP based on the sum of the active power flows PT calculated in steps S22 and S23 and the frequency time differential value dF (t) / dt. Is calculated by the following equation (6).
ΔP = ΔPT (t) − (M / F0) · dF (t) / dt
ΔPT (t) = PT (t) −PT0 (6)
However,
M: Inertia constant (s)
PT0: Sum of active power flow flowing in and out between the other company's system and the power system before the power loss occurs. F0: Reference frequency (Hz)
F: Measurement frequency (Hz)
Here, the value of the inertia constant M is separately set online. Since the supply / demand imbalance amount ΔP calculated in this way changes greatly at the same time as the power failure occurs, high-speed detection can be expected.

ステップＳ２５では、電源脱落判定手段２６が、ステップＳ２４で算出したアンバランス量△Ｐと閾値△Ｐ＿ｌｉｍｉとを比較する。そして、次の（７）式に従いアンバランス量△Ｐが閾値△Ｐ＿ｌｉｍｉｔ以上のとき、ステップＳ２６へ進み、電源脱落有りと判定し、処理を終了する。
△Ｐ≧△Ｐ＿ｌｉｍｉｔ：電源脱落あり
△Ｐ＜△Ｐ＿ｌｉｍｉｔ：電源脱落なし（７）
ステップＳ２５において、アンバランス量△Ｐが閾値△Ｐ＿ｌｉｍｉｔ未満と判定された場合は、電源脱落なしとしてステップＳ２１に戻る。 In step S25, the power-off judgment unit 26 compares the unbalance amount ΔP calculated in step S24 with the threshold value ΔP_limi. When the unbalance amount ΔP is equal to or greater than the threshold value ΔP_limit according to the following equation (7), the process proceeds to step S26, where it is determined that there is a power loss and the process ends.
ΔP ≧ ΔP_limit: Power supply disconnection ΔP <ΔP_limit: Power supply disconnection (7)
If it is determined in step S25 that the unbalance amount ΔP is less than the threshold value ΔP_limit, the process returns to step S21 with no power loss.

なお、計測誤差の影響を回避するため、（６）式で得られた△Ｐの値を数回分平均した上で判定に用いてもよい。また、ステップＳ２５における需給アンバランス量△Ｐが所定値以上との判定が一定回数継続した場合に初めてステップＳ２６に進むようにしてもよい。
以上のように、この発明の実施の形態２によれば、より高速に電源脱落の検出が可能となる。 In order to avoid the influence of measurement error, the value of ΔP obtained by equation (6) may be averaged several times and used for determination. Alternatively, the process may proceed to step S26 for the first time when the determination that the supply / demand imbalance amount ΔP in step S25 is equal to or greater than a predetermined value continues a certain number of times.
As described above, according to the second embodiment of the present invention, it is possible to detect the power loss at a higher speed.

実施の形態３．
上記実施の形態２は、上述した（６）式にて算出した需給アンバランス量△Ｐにより電源脱落の判定を行っている。この値は、電源脱落時点では電源脱落量に近い値であると考えられる。そこで、この実施の形態３では、収集した連系点における有効電力潮流の和及び周波数情報を基に、電源脱落量を求める。図６、図７は、この発明の実施の形態３を示すものであり、図６は電源脱落量算出装置の構成を示す構成図、図７は電源脱落量算出装置の動作を示すフローチャートである。
図６において、電源脱落量算出装置３０は、電源脱落量算出手段３８を有する。その他の構成については、図４に示した実施の形態２と同様のものであるので、相当するものに同じ符号を付して説明を省略する。 Embodiment 3 FIG.
In the second embodiment, the power supply loss is determined based on the supply and demand imbalance amount ΔP calculated by the above-described equation (6). This value is considered to be a value close to the power-off amount at the time of power-off. Therefore, in the third embodiment, the power supply disconnection amount is obtained based on the sum of the active power flow at the collected interconnection points and the frequency information. FIGS. 6 and 7 show Embodiment 3 of the present invention. FIG. 6 is a block diagram showing the configuration of the power supply loss amount calculation device, and FIG. 7 is a flowchart showing the operation of the power supply loss amount calculation device. .
In FIG. 6, the power supply loss amount calculation device 30 includes a power supply loss amount calculation means 38. Since other configurations are the same as those of the second embodiment shown in FIG. 4, the corresponding components are denoted by the same reference numerals and description thereof is omitted.

動作の説明に先立ち、電源脱落量の算出方法について説明する。
電源脱落量の算出のために、まず需給アンバランス量△Ｐを求める。需給アンバランス量△Ｐは、先にあげた（６）式で求めることができる。
ところで、この需給アンバランス量△Ｐは、次の（８）式で表現できる。
△Ｐ＝−（△ＰＭ−Ｐｄｒｏｐ）＋△ＰＬ＋△Ｐｌｏｓｓ（８）
但し、
△ＰＭ：自社系統内発電機の機械入力増加分（電源脱落分を除く）
Ｐｄｒｏｐ：自社系統内での電源脱落量
△ＰＬ：自社系統内での負荷増分
△Ｐｌｏｓｓ：自社系統内での線路ロス増分 Prior to the description of the operation, a method for calculating the power loss amount will be described.
In order to calculate the amount of power loss, first, the supply and demand imbalance amount ΔP is obtained. The supply and demand imbalance amount ΔP can be obtained by the above-described equation (6).
By the way, this supply and demand imbalance amount ΔP can be expressed by the following equation (8).
ΔP = − (ΔPM−Pdrop) + ΔPL + ΔPloss (8)
However,
△ PM: Increase in machine input of the generator in the system (excluding power loss)
Pdrop: Amount of power loss in the company system △ PL: Increase in load within the company system △ Ploss: Increase in line loss in the company system

この内、△ＰＭは発電機の調速制御系動作により変化するが、一般的に調速系の動作時定数は大きいことから、電源脱落直後についてはこの値は零とみなすことができる。また、△ＰＬについては、負荷脱落や負荷変化、負荷の電圧や周波数特性に基づき変化しうるが、自社系統における負荷全体から見た場合、これら変化要因は無視できると考えられる。また、△Ｐｌｏｓｓについても、自社系統内での極端な潮流変化がない限り十分無視できる変数といえる。従って、電源脱落発生直後においては、（８）式は次の（９）式で表現できる。
△Ｐ＝Ｐｄｒｏｐ（９）
すなわち、電源脱落量Ｐｄｒｏｐは電源脱落発生直後の需給アンバランス量△Ｐにほぼ等しい。
従って、電源脱落量Ｐｄｒｏｐは、次の（１０）式で求めることができる。
Ｐｄｒｏｐ＝△ＰＴ（ｔ）−（Ｍ／Ｆ０）・ｄＦ（ｔ）／ｄｔ（１０） Among these, ΔPM varies depending on the speed control system operation of the generator. However, since the operation time constant of the speed control system is generally large, this value can be regarded as zero immediately after the power is turned off. Further, ΔPL can change based on load drop, load change, load voltage and frequency characteristics, but these change factors are considered negligible when viewed from the entire load in the company system. ΔPloss is also a variable that can be sufficiently ignored as long as there is no extreme change in power flow within the company's own system. Therefore, immediately after the occurrence of power loss, the equation (8) can be expressed by the following equation (9).
ΔP = Pdrop (9)
That is, the power drop amount Pdrop is substantially equal to the supply and demand imbalance amount ΔP immediately after the power drop occurs.
Therefore, the power-off amount Pdrop can be obtained by the following equation (10).
Pdrop = ΔPT (t) − (M / F0) · dF (t) / dt (10)

この実施の形態における電源脱落量算出装置３０は、上記（１０）式により電源脱落量Ｐｄｒｏｐを求めるものであり、以下、図７のフローチャートに従って動作を説明する。
ステップＳ２１〜Ｓ２４は、図５のフローチャートにおける処理と同様であり、需給アンバランス量算出手段２４が、（６）式に従って需給アンバランス量△Ｐを算出する。
次に、ステップＳ３１において、電源脱落量算出手段３８が、需給アンバランス量△Ｐに基づき上記（１０）式により電源脱落量Ｐｄｒｏｐを求める。 The power supply loss amount calculation device 30 in this embodiment calculates the power supply loss amount Pdrop by the above equation (10), and the operation will be described below with reference to the flowchart of FIG.
Steps S21 to S24 are the same as the processing in the flowchart of FIG. 5, and the supply and demand imbalance amount calculation means 24 calculates the supply and demand imbalance amount ΔP according to the equation (6).
Next, in step S31, the power supply loss amount calculation means 38 obtains the power supply loss amount Pdrop by the above equation (10) based on the supply and demand imbalance amount ΔP.

以上のように、この発明の実施の形態３によれば、電源脱落が発生しうる箇所の全てに電力計測手段を備えなくても、他の電力系統との連系点における電気的量の情報を用いることで、すなわち比較的少ない情報量に基づいて、容易に電源脱落量を求めることが可能となる。 As described above, according to the third embodiment of the present invention, the information on the electrical quantity at the connection point with another power system can be provided without providing the power measuring means in all the places where the power loss can occur. In other words, it is possible to easily determine the power loss amount based on a relatively small amount of information.

実施の形態４．
先に示した実施の形態２及び３では、その動作の過程において周波数時間微分値を用いている。一般的に計測量の微分値はノイズが重畳しやすいため、得られる結果にも影響を与える可能性がある。このため、この実施の形態４では、演算に用いる周波数の時系列データに最小二乗法等を適用して周波数を求める。図８、図９は、この発明の実施の形態４を示すものであり、図８は電源脱落検出装置の構成を示す構成図、図９は電源脱落検出装置の動作を示すフローチャートである。図８において、電源脱落検出装置４０は、周波数時間微分値計算装置４１を有する。周波数時間微分値計算装置４１は、周波数近似式算出手段４２、周波数時間微分値算出手段４３を有する。その他の構成については、図４に示した実施の形態２と同様のものであるので、相当するものに同じ符号を付して説明を省略する。 Embodiment 4 FIG.
In the second and third embodiments shown above, the frequency time differential value is used in the process of the operation. In general, the differential value of the measured quantity is likely to be superimposed with noise, and thus the obtained result may be affected. For this reason, in the fourth embodiment, the frequency is obtained by applying the least square method or the like to the time-series data of the frequency used for the calculation. 8 and 9 show a fourth embodiment of the present invention. FIG. 8 is a block diagram showing the configuration of the power-off detection device, and FIG. 9 is a flowchart showing the operation of the power-off detection device. In FIG. 8, the power-off detection device 40 has a frequency time differential value calculation device 41. The frequency time differential value calculation device 41 includes a frequency approximate expression calculation means 42 and a frequency time differential value calculation means 43. Since other configurations are the same as those of the second embodiment shown in FIG. 4, the corresponding components are denoted by the same reference numerals and description thereof is omitted.

次に動作について図９のフローチャートに従って説明する。
図９において、ステップＳ２１及びステップＳ２２は、図４に示した電源脱落検出装置２０と同様である。すなわち、ステップＳ２１において、他社系統側から自社系統側に流れる有効電力潮流Ｐｉの計測値及び各地点の周波数Ｆｉの計測値を、情報蓄積手段１１に収集、蓄積する。ステップＳ２２において、収集した有効電力潮流（Ｐｉ）を基に、他社系統から自社系統に流入する有効電力潮流の和ＰＴを、有効電力潮流加算手段１２にて算出する。次に、ステップＳ４１において、周波数時間微分値計算装置４１の周波数近似式算出手段４２により次の（１１）式に示すような周波数の近似式を時間関数として求める。なお、ここでは仮に２次式の例を示しているが、必要に応じて次数を変更しても問題はない。
Ｆ（ｔ）＝ａ０＋ａ１・ｔ＋ａ２・ｔ・ｔ（１１）
ここに、
Ｆ（ｔ）：計測周波数
ａ０：２次近似式の定数項
ａ１：２次近似式の１次の係数
ａ２：２次近似式の２次の係数
ｔ：時間
である。
そして、ステップＳ４２において、周波数時間微分値算出手段４３が時刻ｔ１における周波数時間微分値ｄＦ（ｔ１）／ｄｔを、次の（１２）式を用いて算出する。
ｄＦ（ｔ１）／ｄｔ＝ａ１＋２・ａ２・ｔ１（１２）
ここに、
ｄＦ（ｔ１）／ｄｔ：ｔ１時点の周波数微分
ａ１，ａ２：１１式と同一
ｔ１：時刻
である。
ステップＳ２４において需給アンバランス量算出手段２４が上記のようにして算出した周波数時間徹分値ｄＦ（ｔ１）／ｄｔを用いて需給アンバランス量ΔＰを算出し、ステップＳ２５、ステップＳ２６において電源脱落判定手段２６が電源脱落の発生を判定する。このようにして、より精度の高い検出を行うことができる。
なお、電源脱落量を求める場合も同様であり、実施の形態３における図６に示した周波数時間微分値算出手段２１の代わりにこの実施の形態４における周波数時間微分値計算装置４１を用いれば、より精度の高い電源脱落量の算出を行うことができる。 Next, the operation will be described with reference to the flowchart of FIG.
In FIG. 9, step S21 and step S22 are the same as those of the power-off detection device 20 shown in FIG. That is, in step S21, the measurement value of the active power flow Pi flowing from the other company's system side to the company's system side and the measurement value of the frequency Fi at each point are collected and stored in the information storage unit 11. In step S22, based on the collected effective power flow (Pi), the effective power flow summing means 12 calculates the sum PT of the effective power flows flowing from the other company's system into the system. Next, in step S41, the frequency approximate expression calculating means 42 of the frequency time differential value calculating device 41 obtains an approximate expression of the frequency as shown in the following expression (11) as a time function. Although an example of a quadratic expression is shown here, there is no problem even if the order is changed as necessary.
F (t) = a0 + a1 · t + a2 · t · t (11)
here,
F (t): Measurement frequency a0: Constant term of quadratic approximate expression a1: Primary coefficient of quadratic approximate expression a2: Secondary coefficient of quadratic approximate expression t: Time.
In step S42, the frequency time differential value calculation means 43 calculates the frequency time differential value dF (t1) / dt at time t1 using the following equation (12).
dF (t1) / dt = a1 + 2 · a2 · t1 (12)
here,
dF (t1) / dt: Frequency differentiation at time t1 Same as equations a1 and a2: 11 t1: Time.
In step S24, the supply / demand unbalance amount calculation means 24 calculates the supply / demand unbalance amount ΔP using the frequency time full value dF (t1) / dt calculated as described above. Means 26 determines the occurrence of power loss. In this way, detection with higher accuracy can be performed.
The same applies to the case of obtaining the power loss amount, and if the frequency time differential value calculation device 41 in the fourth embodiment is used instead of the frequency time differential value calculation means 21 shown in FIG. 6 in the third embodiment, It is possible to calculate the power loss amount with higher accuracy.

この発明の実施の形態１における有効電力系統を示す図である。It is a figure which shows the active power grid | system in Embodiment 1 of this invention. この発明の実施の形態１である電源脱落検出装置の構成を示す構成図である。BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram which shows the structure of the power supply loss detection apparatus which is Embodiment 1 of this invention. 電源脱落検出装置の動作を示すフローチャートである。It is a flowchart which shows operation | movement of a power-off detection apparatus. この発明の実施の形態２である電源脱落検出装置の構成を示す構成図である。It is a block diagram which shows the structure of the power-supply-loss detection apparatus which is Embodiment 2 of this invention. 電源脱落検出装置の動作を示すフローチャートである。It is a flowchart which shows operation | movement of a power-off detection apparatus. この発明の実施の形態３である電源脱落量算出装置の構成を示す構成図である。It is a block diagram which shows the structure of the power supply loss amount calculation apparatus which is Embodiment 3 of this invention. 電源脱落量算出装置の動作を示すフローチャートである。It is a flowchart which shows operation | movement of the power supply loss amount calculation apparatus. この発明の実施の形態４である電源脱落検出装置の構成を示す構成図である。It is a block diagram which shows the structure of the power-supply-loss detection apparatus which is Embodiment 4 of this invention. 電源脱落量算出装置の動作を示すフローチャートである。It is a flowchart which shows operation | movement of the power supply loss amount calculation apparatus.

符号の説明Explanation of symbols

２電力計測手段、４情報伝送手段、６周波数計測手段、
１０電源脱落検出装置、１１情報蓄積手段、１２有効電力潮流加算手段、
１４差分算出手段、１６電源脱落判定手段、２０電源脱落検出装置、
２１周波数算出手段、２４需給アンバランス量算出手段、２６電源脱落判定手段、
３０電源脱落量算出装置、３８電源脱落量算出手段、４０電源脱落検出装置、
４１周波数時間微分値計算装置、４２周波数近似式算出手段、
４３周波数計測手段、１００自社系統、２００，３００他社系統、
４０１〜４０４連系線、Ｇ１〜Ｇ４連系点。
2 power measurement means, 4 information transmission means, 6 frequency measurement means,
10 power loss detection device, 11 information storage means, 12 active power flow addition means,
14 difference calculation means, 16 power supply loss determination means, 20 power supply loss detection device,
21 frequency calculation means, 24 supply and demand imbalance amount calculation means, 26 power supply loss determination means,
30 power supply loss amount calculation device, 38 power supply loss amount calculation means, 40 power supply loss detection device,
41 frequency time differential value calculation device, 42 frequency approximation formula calculation means,
43 Frequency measurement means, 100 In-house system, 200,300 Other company system,
401-404 interconnection line, G1-G4 interconnection point.

Claims

自己の電力系統と他の電力系統との連系点を通過する有効電力潮流に基づいて上記自己の電力系統内における電源脱落の有無を判定する電源脱落検出装置。 A power supply loss detection device that determines whether or not a power supply is lost in the self power system based on an active power flow passing through a connection point between the self power system and another power system.

上記連系点を通過する有効電力潮流の和を算出する有効電力潮流加算手段と、上記有効電力潮流の和の所定時間当たりの変化量が所定値以上のとき上記自己の電力系統内に電源脱落が生じたと判定する差分ベース電源脱落判定手段とを備えたものであることを特徴とする請求項１に記載の電源脱落検出装置。 Active power flow adding means for calculating the sum of the active power flows passing through the interconnection point, and when the amount of change per predetermined time of the sum of the active power flows is greater than or equal to a predetermined value, the power is dropped into the own power system. The power supply loss detection device according to claim 1, further comprising difference-based power supply loss determination means for determining that the error has occurred.

上記連系点を通過する有効電力潮流の和を算出する有効電力潮流加算手段と上記連系点における周波数の時間微分値を求める周波数時間微分値算出手段とを有し上記有効電力潮流の和と上記周波数の時間微分値とに基づいて上記自己の電力系統内における需給アンバランス量を算出する需給アンバランス量算出手段と、上記需給アンバランス量が所定値以上のとき上記自己の電力系統内に電源脱落が生じたと判定する需給アンバランス量ベース電源脱落判定手段とを備えたものであることを特徴とする請求項１に記載の電源脱落検出装置。 An active power flow adding means for calculating a sum of active power flows passing through the interconnection point; and a frequency time differential value calculating means for obtaining a time differential value of the frequency at the interconnection point; Supply / demand imbalance amount calculation means for calculating a supply / demand imbalance amount in the own power system based on the time differential value of the frequency, and when the supply / demand imbalance amount is equal to or greater than a predetermined value, 2. The power supply loss detection apparatus according to claim 1, further comprising a supply / demand imbalance amount-based power supply loss determination means for determining that a power loss has occurred.

上記周波数時間微分値算出手段は、上記周波数の近似式を時間関数として求め上記近似式により求めた周波数について時間微分値を求めるものであることを特徴とする請求項３に記載の電源脱落検出装置。 4. The power loss detection device according to claim 3, wherein the frequency time differential value calculation means calculates an approximate expression of the frequency as a time function and calculates a time differential value for the frequency obtained by the approximate expression. .

自己の電力系統と他の電力系統との連系点を通過する有効電力潮流の和を算出する有効電力潮流加算手段と上記連系点における周波数の時間微分値を求める周波数時間微分値算出手段とを有し上記有効電力潮流の和と上記周波数の時間微分値とに基づいて上記自己の電力系統内における需給アンバランス量を算出する需給アンバランス量算出手段と、上記需給アンバランス量に基づいて上記自己の電力系統内に発生した電源脱落量を求める電源脱落量算出手段とを備えた電源脱落量算出装置。 An active power flow adding means for calculating the sum of the active power flows passing through the connection point between the own power system and another power system, and a frequency time differential value calculating means for calculating a time differential value of the frequency at the connection point; Supply and demand imbalance amount calculating means for calculating the supply and demand imbalance amount in the power system based on the sum of the active power flow and the time differential value of the frequency, and based on the supply and demand imbalance amount A power supply loss amount calculating device comprising: a power supply loss amount calculating means for obtaining a power supply loss amount generated in the self power system.

上記周波数時間微分値算出手段は、上記周波数の近似式を時間関数として求め上記近似式により求めた周波数について時間微分値を求めるものであることを特徴とする請求項５に記載の電源脱落量算出装置。
6. The power supply loss amount calculation according to claim 5, wherein the frequency time differential value calculating means calculates an approximate expression of the frequency as a time function and calculates a time differential value for the frequency determined by the approximate expression. apparatus.