JPS59103520A - Power tide control system for substation parallel system dc multiterminal system - Google Patents

Abstract

(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

【発明の詳細な説明】 本発明は変換所並列方式をとる直流多端子系の電力潮流
制御方式に関するもので、変換所制御の高信頼度化を目
的とするものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power flow control system for a DC multi-terminal system using a converter station parallel system, and is aimed at increasing the reliability of converter station control.

変換所並列方式をとる直流多端子系例えば第１図に示す
系統図のように、直流線路り１．Ｌ２を介して並列接続
された順変換所ＤＥＩ１．ＤＳ２　と、直流線路り６．
ＩＪ４を介して並列接続された逆変換所Ｉｓ、、Ｉｓ２
とを、直流線路りによって並列接続して形成された直流
四端子系においては、従来法に示すような運転による電
力潮流の制御方式がとられている。For example, in a DC multi-terminal system that uses a converter station parallel system, as shown in the system diagram shown in Figure 1, a DC line 1. Forward conversion station DEI1. connected in parallel via L2. DS2 and DC line6.
Inverter stations Is, , Is2 connected in parallel via IJ4
In a DC four-terminal system formed by connecting the two in parallel via a DC line, a method of controlling the power flow through operation as shown in the conventional method is used.

即ち各変換所の制御により、それぞれにその定格電流値
工（１１１■ｄ２１工ｄ！１１工ｄ４において定電流制
御が行われるようにした、第２図（ｃＬ）（１））（Ｃ
）（ｄ）に示す如き直流電圧電流特性をもたせ（第２図
中電流の増加による電圧の低下は、変換所における電圧
降下にもとづくもので、意識的にもたせたものではない
）、第２図中に示す破線と各変換所の直流電圧電流特性
曲線図との交点によって示すように、順変換所ＤＢ１．
ＤＢ２の電流設定値の和（工□、土工（１２）と、逆変
換所工Ｓ１．工Ｓ２の電流設定値の和（工ｄｌ＋工ｄ４
　）との差電流が、（１）式のように系統の充電電流な
どの確保、事故時の電流変動の抑制などに必要とされる
。所謂電流マージンΔ崎を常に与えるように各変換所の
電圧電流の設定値を制御して、所要の（Ｉｄ＋＋Ｉａｚ
）　　（Ｉｄ３＋Ｉｄ４）＝ΔＩｄ　　・・・・・・（
１）電力分配のもとに運転を行うようにしている。この
ようにすれば何等からの原因により、順変換所ンΔ工□
が得られるように、正確迅速に各変換所の応動制御を行
うことにより、新しい運転点に移行させて新たな電力潮
流の下に安定な運転の継続が可能である。That is, by controlling each converter station, constant current control is performed at each rated current value (111 d21 d! 11 d4, Figure 2 (cL) (1)) (C
) (d) (The voltage drop due to the increase in current in Figure 2 is based on the voltage drop at the converter station, and is not intentionally created.) As shown by the intersection of the broken line shown inside and the DC voltage-current characteristic curve diagram of each converter station, the forward converter station DB1.
The sum of the current setting values of DB2 (engine □, earthwork (12) and the sum of the current settings of the inverse conversion station engineering S1.
), as shown in equation (1), is required to ensure the charging current of the grid, suppress current fluctuations in the event of an accident, etc. The voltage and current setting values of each converter station are controlled so as to always give a so-called current margin Δz, and the required (Id++Iaz
) (Id3+Id4)=ΔId ・・・・・・(
1) Operation is based on power distribution. In this way, due to some reason, the forward conversion station □
By performing responsive control of each converter station accurately and quickly so as to obtain the following conditions, it is possible to shift to a new operating point and continue stable operation under the new power flow.

ところで上記のように電流設定値の差による、総電流値
に対して著しく小さい電流マージンを、運転条件の変更
に対応して確保するためには、各変換所からの電圧、電
流などの情報信号にもとづき、各変換所を関連して正確
に制御しうる集中制御が必要とされる。しかし一般に順
変換所ＤＳ、。By the way, in order to ensure a current margin that is extremely small compared to the total current value due to the difference in current setting values as mentioned above, in response to changes in operating conditions, information signals such as voltage and current from each converter station must be Based on this, there is a need for a centralized control that can accurately control each converter station in conjunction. However, generally forward conversion station DS,.

ＤＳ２間、逆変換所Ｉｓ、、工Ｅｊ２　間、更には順、
逆変換所間は距離をもつのが通常である。このため各変
換所の中の特定の変換所、例えば第１図に示す順変換所
ＤＳ２内に集中制御装置ＣＣを設けて、直接変換所制御
装置ＬＣ２を接続できても、他の変換所ＤＩ３．　、Ｉ
Ｓ、　、工Ｓ２の制御装置ＬＯ，、ＬＯ，、ＬＯ４と集
中制御装置００間の接続に当っては、情報信号の伝送、
系ＳＬ、　、　ＳＬ、　、　ＳＬ４　に頼らざるを得な
い。従ってこのよう々従来の方式においては、正確な制
御情報の伝送を妨げるような素因をもっことのない、高
信頼度の伝送系が要求される欠点がある。Between DS2, inverse conversion station Is, and Ej2, and further forward,
There is usually a distance between inverse transform stations. For this reason, even if a central control device CC is provided in a specific converter station among each converter station, for example in the forward converter station DS2 shown in FIG. 1, and the converter station controller LC2 can be directly connected, other converters ．． , I
When connecting between the control devices LO, LO, and LO4 of S, S2 and the central control device 00, transmission of information signals,
We have no choice but to rely on the systems SL, , SL, , SL4. Therefore, these conventional systems have the disadvantage that a highly reliable transmission system is required, which is free from any predisposing factors that would impede accurate transmission of control information.

本発明は潮流制御に当って、各変換所を伝送系を用いて
関連的に集中制御することなく、各変換所（（おける設
定直流電圧の制御により、自動的に所要の電流マージン
を得ながら、新しい運転点への潮流変更が可能となるよ
うにしたものである。In power flow control, the present invention automatically obtains the required current margin by controlling the set DC voltage at each converter station (() without centrally controlling each converter station in relation to each other using a transmission system. , it is possible to change the power flow to a new operating point.

次に図面を用いてその詳細を説明する。Next, the details will be explained using the drawings.

本発明の特徴とするところは次の点にある。例えば第１
図に示した四端子系の順変換所Ｄｓ１．Ｄｓ２に、第５
図（αバｂ）に示す直流電圧電流特性、即ち定格値Ｉ、
４．Ｉｄ２において定電流側脚が行われるまで、直流電
流の増加に伴い直流電圧が低下する特性（ｃＬ、）（α
２）をもたせる。また逆変換所工Ｓ＋、■ｓ２において
は第５図（ｃＨｄ）に示すように、定格値ＩＣ１５１工
ｄ４において定電流制御が行われるまで、直流電流の増
加に伴い直流電圧が高くなる直流電圧電流特性（ｂ、）
（ｂ２）をもたせて、第６図に示す特性図のように順変
換所ＤＳ４．ＤＳ２の総合特性（Ａ）、Ｊ：、逆変換所
工ｓ、　、ＩＳ２のそれ（Ｂ）とが、逆な電圧の傾斜を
もった直流電圧電流特性となるようにする。The features of the present invention are as follows. For example, the first
Forward conversion station Ds1 of the four-terminal system shown in the figure. Ds2, 5th
The DC voltage and current characteristics shown in the figure (αb), that is, the rated value I,
4. Until the constant current side leg is performed at Id2, the DC voltage decreases as the DC current increases (cL, ) (α
2). In addition, as shown in Figure 5 (cHd) in the inverse converter S+ and ■s2, the DC voltage and current increase as the DC current increases until constant current control is performed at the rated value IC151 and d4. Characteristic (b,)
(b2), the forward conversion station DS4. The overall characteristic (A) of DS2, J:, inverse conversion process, and that of IS2 (B) are made to have DC voltage-current characteristics with an opposite voltage slope.

そして両者が電流流通の初期においてもつ電圧差により
、直流線路の充電のための電流を流しうるようにする。The voltage difference between the two at the initial stage of current flow allows current to flow for charging the DC line.

また特性Ａ、Ｂの交点即ち順逆変換所の電流が正負平衡
となる安定運転点において運転するようにして変換所中
の何れか１箇所例えばＤＳ、の直流電圧の設定値を変え
ることにより、第５図（α）中に点線（鴫）によって示
すように、例えば傾斜をそのままとして上下させるか、
または傾斜を変えることにより、図中ＰＩ／のように安
定運転点を移動させつるようにして、潮流を制御しつる
ようにしたことを特徴とするものである。In addition, by changing the set value of the DC voltage at one point in the converter station, for example, DS, by operating at the intersection of characteristics A and B, that is, a stable operating point where the current of the forward and reverse converter station is in positive and negative balance. For example, as shown by the dotted line (dotted line) in Figure 5 (α), you can leave the slope as it is and move it up and down, or
Alternatively, by changing the inclination, the stable operating point is moved as shown by PI/ in the figure, thereby controlling the tidal current.

このようにすれば例えば交流側電圧が変化し、これによ
る潮流制御が必要な場合にも、直流側電圧を制御情報と
して、該当変換所の電圧設定値を変えることにより、新
しい安定運転点に移行させて、新しい潮流で安定な運転
を行いつる。従って例えば各変換所の直流電圧電流特性
の設定に、伝送系に依存した集中制御が必要であったと
しても、上記のような系統条件の変化に対しては、伝送
系に依存することなく電圧を情報として迅速に対応でさ
、それだけ伝送系への依存度が少なくなって、制御の高
信頼度化を達成できる。In this way, for example, even if the AC side voltage changes and power flow control based on this is required, the DC side voltage can be used as control information and the voltage setting value of the relevant converter station can be changed to move to a new stable operating point. By doing so, we will be able to operate stably with new trends. Therefore, for example, even if centralized control that depends on the transmission system is required to set the DC voltage and current characteristics of each converter station, voltage control can be controlled independently of the transmission system in response to changes in system conditions such as those mentioned above. The more information you can respond to, the more dependence you have on the transmission system, and the more reliable your control can be.

次に本発明を具体化するための順逆変換所の制御系、お
よび起動方式について説明する。なお線路事故による停
止後の再起動については、事故発生後進変換所がバイパ
スベアとなるのを待って、起動操作を行えばよいのでそ
の説明は省略する。Next, a control system and a starting method for a forward/reverse converter station for embodying the present invention will be described. Regarding restarting after a stoppage due to a track accident, the explanation will be omitted since the restarting operation can be performed after waiting for the reverse converter station where the accident occurred to become a bypass bear.

オフ図は順変換所の制御系を示すブロック系統図であっ
て、従来の制御系において潮流の分配量を決定する傾斜
係数の設定回路（１）と傾斜制御回路（２）を設けたも
のである。そして標準電圧値ＥＥ３　と直流電圧検出値
チ、、の比較回路（３）の出力と、傾斜係数設定回路（
１）を介して得られる、標準電流指定位相゛と直流電流
検出値ｉｅＬの比較回路（４）の出方とを比較回路（５
）により比較したのち、傾斜制御回路（２）に加えて、
変換器の位相制御角φｄを第５図に示した電圧電流特性
となるように制御する。なお（６）は直流電流最大制限
値■、の設定用の出力と直流電圧検出値工□の比較回路
、（７）は直流電流最大値制限回路、（８）は電圧低下
時電流制限値設定回路（９）は最大′疏流値選択回路、
（１０）はリミッタであって、直流電流最大制限値設定
出力几を制御することにより、直流電流最大制限値の増
加が行われ、定格電流値において第５図（ｔｌ、）（ｂ
）中のＣＩのように定電流制御が行われる。また電圧低
工時電流制限回路（８）の出力により、第５図（α）（
ｂ）中の■工のように必要以上の電圧低工時電流制限が
行われる。The off-line diagram is a block system diagram showing the control system of a forward conversion station, and is a conventional control system that includes a slope coefficient setting circuit (1) and a slope control circuit (2) that determine the distribution amount of power flow. be. Then, the output of the comparison circuit (3) between the standard voltage value EE3 and the detected DC voltage value CH, and the slope coefficient setting circuit (
The comparison circuit (5) compares the output of the standard current specified phase ' obtained through the comparison circuit (4) with the standard current specified phase ' obtained through the comparison circuit (4) through the DC current detection value ieL
), and in addition to the slope control circuit (2),
The phase control angle φd of the converter is controlled to have the voltage-current characteristics shown in FIG. Note that (6) is a comparison circuit between the output for setting the maximum DC current limit value ■ and the DC voltage detection value □, (7) is the maximum DC current limit circuit, and (8) is the current limit value setting at voltage drop. Circuit (9) is a maximum current value selection circuit;
(10) is a limiter, which increases the maximum DC current limit value by controlling the maximum DC current limit setting output unit, and increases the maximum DC current limit value at the rated current value as shown in FIG.
) Constant current control is performed like CI in ). In addition, the output of the current limiting circuit (8) during low voltage installation causes the
b) As shown in step (2), the current is limited when the voltage is lower than necessary.

第８図は逆変換器の制御系を示すブロック系統図であっ
て、従来の制御系において傾斜係数設定回路（１）と、
傾斜制御回路（２）を設けて逆変換器の位相制御角θ工
を制御するものであって、順変換所と異なる点は定余裕
角制御回路（１りと最小値選択回路（２）を備えている
点が異なるのみである。次に本発明方式の起動について
説明する。FIG. 8 is a block system diagram showing the control system of the inverse converter, and the conventional control system includes a slope coefficient setting circuit (1),
A slope control circuit (2) is provided to control the phase control angle θ of the inverse converter, and the difference from the forward converter is that a constant margin angle control circuit (1) and a minimum value selection circuit (2) are provided. The only difference is in the features provided.Next, the activation of the system of the present invention will be explained.

逆変換所工Ｓ　＋　＋工Ｓ２　　をバイパスペア状態と
し、また順変換所ＤＳ、、ＤＳ２　　をディブロックの
状態として直流線路に電圧を加える。そして第９図（α
）（句（Ｃ）（ｄ）に示す特性図のように、順変換所Ｄ
ｓ１．Ｄｓ２の電流最大制御値を徐々に増加する。そし
て逆変換器Ｉｓ、、、ＴＳ２に直流電流−５が流れたこ
とが確認されたとき、瞬時に逆変換所工ｓ４．■ｓ２を
ティブロックする。すると各直流線路Ｌ　、　Ｌ４．Ｌ
２．’Ｌ３．Ｌ４などは、順変換所Ｄｓ１．Ｄｓ２と逆
変換所工ｓ１．■ｓ２　との電流差により、充電されて
第１ｏ図の総合特性図に示すｙ点において運転され、以
後電流最大制限値を１Ｉｎ２１”ｍ５　と増加すること
により、運転点はｐ、ｐと移動して、安定な運転点Ｐに
達し、各変換所の電圧の傾斜に対応した負荷分配量のも
とに定常運転状態となる。The inverse converter station S + + unit S2 is put into a bypass pair state, and the forward converter stations DS, DS2 are put into a deblock state, and a voltage is applied to the DC line. And Figure 9 (α
) (As shown in the characteristic diagram shown in clause (C) (d), forward conversion station D
s1. Gradually increase the current maximum control value of Ds2. Then, when it is confirmed that the DC current -5 has flowed through the inverter Is,..., TS2, the inverter s4... ■Tee lock s2. Then, each DC line L, L4. L
2. 'L3. L4 etc. are the forward conversion station Ds1. Ds2 and inverse conversion work s1. ■Due to the current difference with s2, it is charged and operated at point y shown in the comprehensive characteristic diagram in Figure 1o.After that, by increasing the maximum current limit value to 1In21"m5, the operating point moves from p to p. Then, a stable operating point P is reached, and a steady operating state is established under the load distribution amount corresponding to the voltage gradient of each converter station.

以上の説明から明らかなように、本発明は順変換所に直
流電流の増加と共に直流電圧が低下し、また逆変換器に
おいては直流電流の増加と共に直流電圧が上昇する、順
および逆変換器において逆な直流電圧の傾斜をもった直
流電圧電流特性をもたせ、運転開始時において順逆変換
器間の電流差により線路を充電するようにしたのち、順
、逆変換器の直流電流の平衡点において運転するように
している。従って交流側電圧の変動などに対応する潮流
制御を、電圧を制御情報として行いつる。As is clear from the above description, the present invention is applicable to forward and inverse converters, in which the DC voltage decreases as the DC current increases in the forward converter station, and the DC voltage increases as the DC current increases in the inverse converter. The DC voltage current characteristic has a reverse DC voltage slope, and the line is charged by the current difference between the forward and reverse converters at the start of operation, and then the line is charged at the point where the DC currents of the forward and reverse converters are balanced. I try to do that. Therefore, power flow control corresponding to fluctuations in AC voltage can be performed using voltage as control information.

従って従来方式のように電流マージを得るように各変換
所を集中制御する場合に比べて、制御情報伝送系への依
存度が少なくなり、制御をそれだけ高信頼度化できる。Therefore, compared to the case where each converter station is centrally controlled to obtain current merging as in the conventional system, there is less dependence on the control information transmission system, and control can be made that much more reliable.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は変換所並列方式をとる直流多端系の系統図、第
２図、第３図、第４図は従来方式による変換所の制御特
性図、第５図および第６図は本発明による各変換所の制
御特性図およびその総会特性図、オフ図および第８図は
本発明のための順および逆変換器の制御系の一例を示す
ブロック系統図、第９図Ｈ（ｂ）（ｃ）（ｄ）および第
１ｏ図は本発明方式の起動時の各変換所の制御特性図お
よび総合特性図である。 ＤＳ、、ＤＳ２・・・順変換所、　工Ｓ、、工ｓ２・・
・逆変換器、Ｌ　、　Ｌ４．Ｌ２．Ｌ３．Ｌ４−・・直
流線路、　　ｃｃ・・・集中制御装置、　ＬＯ４，ＬＯ
２，ＬＣ３，ＬＯ４，・・・変換所制御卸装置、ＳＬ、
、ＳＬ２．ＳＬ３．．５Ｌ４−・・情報伝送系、　（１
）−・・傾斜係数設定回路、　（２）・・・傾斜制御回
路、（３）（４）（５）（６）・・・比較回路、　（７
）・・・直流電流最大値制限回路、　（８）・・・電圧
低下時電流制限値設定回路、（９）・・・最大値選択回
路、　（１ｏ）・・・リミッタ、　（１１）・・・定余
裕角制御回路、　（１２）・・・最小値選択回路、Ｅｓ
・・・標準電圧値、　Ｅｄ・・・直流電圧検出値、■ｏ
・・・標準電流指定値、　工□・・・直流電流検出値。 特許出願人　財団法人　電力中央研究所代理人弁理士大
塚　学 外１名Figure 1 is a system diagram of a DC multi-end system that uses a converter station parallel system, Figures 2, 3, and 4 are control characteristic diagrams of a converter station using the conventional system, and Figures 5 and 6 are based on the present invention. The control characteristic diagram of each converter station, its general characteristic diagram, OFF diagram, and FIG. )(d) and FIG. 1o are control characteristic diagrams and comprehensive characteristic diagrams of each converter station at the time of startup of the system of the present invention. DS,,DS2...Forward conversion station, Engineering S,, Engineering s2...
- Inverse converter, L, L4. L2. L3. L4--DC line, cc... Centralized control device, LO4, LO
2, LC3, LO4, ... Conversion station control device, SL,
, SL2. SL3. ．． 5L4--Information transmission system, (1
) -...Slope coefficient setting circuit, (2)...Slope control circuit, (3) (4) (5) (6)... Comparison circuit, (7
)...DC current maximum value limiting circuit, (8)...Current limit value setting circuit at voltage drop, (9)...Maximum value selection circuit, (1o)...Limiter, (11)...・Constant margin angle control circuit, (12)...minimum value selection circuit, Es
...Standard voltage value, Ed...DC voltage detection value, ■o
...Standard current specified value, ...DC current detection value. Patent applicant Otsuka, patent attorney representing the Central Research Institute of Electric Power Industry (1 person from outside the university)

Claims (1)

【特許請求の範囲】[Claims] （リ　順変換所に直流電流の増加に伴い直流電圧が低下
する直流電圧電流特性をもたせ、また逆変換所には直流
電流の増加に伴い直流電圧が上昇する直流電圧電流特性
をもたせて運転し、変換所の直流電圧の変化により順逆
変換所の直流電流の平衡点を移動させて潮流制御を行う
ことを特徴とする変換所並列方式直流多端子系の電力潮
流制御方式。(i) The forward conversion station is operated with a DC voltage-current characteristic in which the DC voltage decreases as the DC current increases, and the reverse conversion station is operated with a DC voltage-current characteristic in which the DC voltage increases as the DC current increases. , a converter station parallel type DC multi-terminal power flow control system, characterized in that power flow control is performed by moving the DC current equilibrium point of a forward/reverse converter station according to changes in the DC voltage of the converter station.