JP3627491B2 - Operation method of DC arc furnace equipment - Google Patents

Operation method of DC arc furnace equipment Download PDF

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JP3627491B2
JP3627491B2 JP00205898A JP205898A JP3627491B2 JP 3627491 B2 JP3627491 B2 JP 3627491B2 JP 00205898 A JP00205898 A JP 00205898A JP 205898 A JP205898 A JP 205898A JP 3627491 B2 JP3627491 B2 JP 3627491B2
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input power
arc furnace
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JPH11204250A (en
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啓 淡中
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Fuji Electric Co Ltd
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Fuji Electric Systems Co Ltd
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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Description

【０００１】
【発明の属する技術分野】
この発明は、アーク電圧を設定する直流電圧設定値と、電極電流を設定する直流電流設定値とに基づく直流アーク炉設備の運転方法に関する。
【０００２】
【従来の技術】
図３は、この種の直流アーク炉設備の運転方法の従来例を示す回路構成図であり、１は商用電源などの電力系統、１０は直流アーク炉設備を示す。
この直流アーク炉設備１０は炉用遮断器１１と、炉用変圧器１２と、サイリスタ整流装置１３と、電極１４と、炉体１５と、炉底電極１６と、直流リアクトル１７と、溶解材料１８と、計器用変流器（ＣＴ）１９，２０と、整流回路２１，２２と、加算器２３と、直流電流設定器２４と、加算器２５と、電流調節器２６と、点弧角調整器２７と、電圧検出器２８と、直流電圧設定器２９と、加算器３０と、電流調節器３１と、電極昇降装置３２とから構成されている。
【０００３】
図３において、先ず、図示しない起動回路により炉用遮断器１１が投入されると、電極昇降装置３２を介した電極１４と溶解材料１８とが接触している状態で、前記起動回路により点弧角調整器２７を介したサイリスタ整流装置１３から電極１４に起動電流を流し、この起動電流と電極昇降装置３２を介して電極１４を上昇させることにより、電極１４と溶解材料１８との間にアークが発生し、この直流アーク炉設備１０の起動が完了する。
【０００４】
次に、上述の起動が完了すると、操作員が直流電流設定器２４と直流電圧設定器２９とを操作し、操作された直流電圧設定器２９の直流電圧設定値と、電圧検出器２８を介した電極１４と炉底電極１６との間のアーク電圧との偏差を加算器３０で求め、この偏差が零になる昇降量を電圧調整器３１が出力し、この昇降量に従って電極昇降装置３２が電極１４の位置を調整することによりアーク電圧を所望の値に制御しつつ、同時に、操作された直流電流設定器２４の直流電流設定値と、ＣＴ１９，２０それぞれの二次電流を整流回路２１，２２それぞれにより直流電流に変換し、これらの直流電流を加算器２３で加算した電極電流との偏差を加算器２５で求め、この偏差が零になる点弧角指令値を電流調節器２６が出力し、この点弧角指令値に基づいた点弧位相のゲート信号を点弧角調整器２７が出力し、このゲート信号をサイリスタ整流装置１３を構成するそれぞれのサイリスタに与えることにより、電力系統１から炉用変圧器１２とサイリスタ整流装置１３と直流リアクトル１７とを介して得られる電極１４の電極電流が所望の値に制御され、炉体１５の中の溶解材料１８が溶解し続ける。
【０００５】
【発明が解決しようとする課題】
前述の従来の直流アーク炉設備１０においては、溶解材料１８の最適な溶解状態を維持するため、その都度、操作員が直流電流設定器２４と直流電圧設定器２９とをそれぞれ操作する。
しかしながら、電力系統１が余力の少ない電力系統の場合、上述の操作をされた直流電流設定器２４，直流電圧設定器２９それぞれの設定値の積である直流アーク炉設備１０の新たな投入電力値Ｗ１ と、該操作を行う直前の投入電力値Ｗ０ との差が大きいと、この操作に基づいて電力系統１の電圧が大きく変動し、この電圧変動が直流アーク炉設備１０や電力系統１の他の電力機器に悪影響を与えるという問題があった。
【０００６】
この発明の目的は、上記問題点を解決する直流アーク炉設備の運転方法を提供することにある。
【０００７】
【課題を解決するための手段】
この発明は、直流電圧設定値に基づいて電極昇降装置の昇降量を調整することによりアーク電圧を制御しつつ、直流電流設定値に基づいてサイリスタ整流装置を構成するサイリスタの点弧角を調整することにより電極電流を制御して運転される直流アーク炉設備において、
前記直流電圧設定値又は直流電流設定値のいずれか一方若しくは双方を新たな値に設定する操作が行われたときに、この直流電圧設定値と直流電流設定値とにより前記直流アーク炉設備の新たな投入電力値Ｗ１ を演算し、この新たな投入電力値Ｗ１ が前記操作を行う直前の前記直流アーク炉設備の投入電力値Ｗ０ に対して所定の変化幅値（Ｗ０ ±Δｗ）の範囲内のときには、この投入電力値Ｗ１ に対応した前記直流電圧設定値と直流電流設定値とに基づいて該直流アーク炉設備を運転し、前記投入電力値Ｗ１ が前記変化幅値（Ｗ０ ＋Δｗ）を超過しているときには、投入電力値が前記Ｗ０ ＋Δｗになる直流電流設定値を演算し、この演算された直流電流設定値と前記直流電圧設定値とに基づいて前記直流アーク炉設備を予め定めた時間運転し、この時間を経過した後は前記投入電力値Ｗ１ に対応した前記直流電圧設定値と直流電流設定値とに基づいて該直流アーク炉設備を運転し、前記投入電力値Ｗ１ が前記変化幅値（Ｗ０ −Δｗ）未満のときには、投入電力値が前記Ｗ０ −Δｗになる直流電流設定値を演算し、この演算された直流電流設定値と前記直流電圧設定値とに基づいて前記直流アーク炉設備を予め定めた時間運転し、この時間経過した後は前記投入電力値Ｗ１ に対応した前記直流電圧設定値と直流電流設定値とに基づいて該直流アーク炉設備を運転する。
【０００８】
この発明によれば、操作員により設定された直流電流設定値と直流電圧設定値と積である直流アーク炉設備の新たな投入電力値Ｗ１ と該操作をされる直前の投入電力値Ｗ０ との差が大きいときには、所定の時間電力系統が許容する電圧変動になる投入電力値（Ｗ０ ±Δｗ）で該直流アーク炉設備を所定の時間運転し、その後、該直流アーク炉設備を前記投入電力値Ｗ１ で運転するようにしている。
【０００９】
【発明の実施の形態】
図１は、この発明の直流アーク炉設備の運転方法の実施例を示す回路構成図であり、図３に示した従来例回路と同一機能を有するものには同一符号を付して、その説明を省略する。
すなわち図１に示した直流アーク炉設備４０には炉用遮断器１１、炉用変圧器１２、サイリスタ整流装置１３、電極１４、炉体１５、炉底電極１６、直流リアクトル１７、溶解材料１８、計器用変流器１９，２０、整流回路２１，２２、加算器２３、直流電流設定器２４、加算器２５、電流調節器２６、点弧角調整器２７、電圧検出器２８、直流電圧設定器２９、加算器３０、電流調節器３１、電極昇降装置３２の他に、電流設定値演算回路４１を備えている。
【００１０】
この直流アーク炉設備４０の運転方法を、図２に示す電流設定値演算回路４１の動作のフローチャートを参照しつつ、以下に説明する。
先ず、直流アーク炉設備４０を起動完了させるまでの手順は、図３に示した直流アーク炉設備１０における手順と同様である。
次に、直流アーク炉設備４０が起動完了すると、電流設定値演算回路４１が起動時の投入電力値をＷ０ の初期値とし、後述のタイマフラグのリセット状態を初期値として、図２のフローチャートに示す動作を開始する。
【００１１】
図２において、最初にこのフローチャートに入ると、タイマフラグがリセット状態にあるので（ステップＳ１１，分岐Ｎ）、操作員が操作をした直流電流設定器２４および直流電圧設定器２９それぞれの設定値を読み込み（ステップＳ１２）、この読み込み値は前記操作によることから（ステップＳ１３，分岐Ｙ）、ステップＳ１４に移る。
【００１２】
ステップＳ１４では、ステップＳ１２で読み込んだ直流電流設定器２４の設定値と直流電圧設定器２９の設定値との積を求め、これを今回の投入電力値Ｗ１ として、ステップ１５に移る。
ステップＳ１５では、ステップＳ１４で求めた投入電力値Ｗ１ と記憶されている投入電力値Ｗ０ とを比較し、その差の絶対値が予め定めた値（Δｗ）以内であれば（分岐▲１▼）、投入電力値Ｗ１ を新たな投入電力値Ｗ０ として記憶し（ステップＳ１６）、ステップＳ１２で読み込んだ直流電流設定器２４の設定値を直流電流設定値として加算器２５へ出力し（ステップＳ１７）、直流アーク炉設備４０は電流設定値演算回路４１が出力する前記直流電流設定値と、直流電圧設定器２９が出力する直流電圧設定値とに基づく運転が行われる。
【００１３】
ステップＳ１５で、ステップＳ１４で求めた投入電力値Ｗ１ が記憶されている投入電力値Ｗ０ に基づく変化幅値（Ｗ０ ＋Δｗ）を超過しているときには（分岐▲２▼）、投入電力値が前記Ｗ０ ＋Δｗになる直流電流設定値を、ステップＳ１２で読み込んだ直流電圧設定器２９の設定値と該（Ｗ０ ＋Δｗ）とから演算し、この演算値を直流電流設定値として加算器２５へ出力して（ステップＳ１８）、タイマを起動し（ステップＳ１９）、このタイマが所定の時間を経過していないので（ステップＳ２０，分岐Ｎ）、該タイマが起動中であるからタイマフラグをセットし（ステップＳ２１）、直流アーク炉設備４０は電流設定値演算回路４１が出力する前記直流電流設定値と、直流電圧設定器２９が出力する直流電圧設定値とに基づく運転が行われる。
【００１４】
ステップＳ１５で、ステップＳ１４で求めた投入電力値Ｗ１ が記憶されている投入電力値Ｗ０ に基づく変化幅値（Ｗ０ −Δｗ）未満のときには（分岐▲３▼）、投入電力値が前記Ｗ０ −Δｗになる直流電流設定値を、ステップＳ１２で読み込んだ直流電圧設定器２９の設定値と該（Ｗ０ −Δｗ）とから演算し、この演算値を直流電流設定値として加算器２５へ出力して（ステップＳ２２）、タイマを起動し（ステップＳ１９）、このタイマが所定の時間を経過していないので（ステップＳ２０，分岐Ｎ）、該タイマが起動中であるからタイマフラグをセットし（ステップＳ２１）、直流アーク炉設備４０は電流設定値演算回路４１が出力する前記直流電流設定値と、直流電圧設定器２９が出力する直流電圧設定値とに基づく運転が行われる。
【００１５】
また図２において、ステップＳ１１でタイマフラグがセットされた状態にあることは（分岐Ｙ）、前回またはそれ以前の回にステップＳ１４で求めた投入電力値Ｗ１ と記憶されている投入電力値Ｗ０ との差の絶対値が予め定めた値（Δｗ）を超えた上述のステップＳ１８またはステップＳ２２での運転状態にあるので、ステップＳ２０に移り、この時、タイマが所定の時間を経過しておれば（分岐Ｙ）、タイマを停止させ、タイマフラグをリセットし（ステップＳ２３）、投入電力値Ｗ１ を新たな投入電力値Ｗ０ として記憶し（ステップＳ１６）、ステップＳ１２で読み込んだ直流電流設定器２４の設定値を直流電流設定値として加算器２５へ出力し（ステップＳ１７）、直流アーク炉設備４０は電流設定値演算回路４１が出力する前記直流電流設定値と、直流電圧設定器２９が出力する直流電圧設定値とに基づく運転が行われる。
【００１６】
さらに図２において、直流アーク炉設備４０が現状の電流設定値演算回路４１が出力する直流電流設定値と直流電圧設定器２９が出力する直流電圧設定値とに基づく運転で、最適な溶解状態を維持しておれば、タイマフラグもリセット状態にあり（ステップＳ１１，分岐Ｎ）、操作員による設定値変更も行われていので（ステップＳ１３，分岐Ｎ）、ステップ２４では、ステップＳ１２で読み込んだ直流電流設定器２４の設定値と直流電圧設定器２９の設定値との積を求め、これを投入電力値Ｗ０ として、ステップ１７に移り、ステップＳ１７ではステップＳ１２で読み込んだ直流電流設定器２４の設定値を直流電流設定値として加算器２５へ出力し、直流アーク炉設備４０は電流設定値演算回路４１が出力する前記直流電流設定値と、直流電圧設定器２９が出力する直流電圧設定値とに基づく運転が行われる。
【００１７】
【発明の効果】
この発明によれば、直流アーク炉設備の溶解材料が最適な溶解状態を維持するために、操作員により設定された直流電流設定値と直流電圧設定値と積である直流アーク炉設備の新たな投入電力値Ｗ１ と該操作をされる直前の投入電力値との差が大きいときには、所定の時間電力系統が許容する電圧変動になる投入電力値で該直流アーク炉設備を所定の時間運転し、その後、該直流アーク炉設備を前記投入電力値Ｗ１ で運転することで、特に余力の少ない電力系統に対して好適な直流アーク炉設備になる。
【図面の簡単な説明】
【図１】この発明の直流アーク炉設備の運転方法の実施例を示す回路構成図
【図２】図１の動作を説明するフローチャート
【図３】従来の直流アーク炉設備の運転方法を示す回路構成図
【符号の説明】
１…電力系統、１０…直流アーク炉設備、１１…炉用遮断器、１２…炉用変圧器、１３…サイリスタ整流装置、１４…電極、１５…炉体、１６…炉底電極、１７…直流リアクトル、１８…溶解材料、１９，２０…計器用変流器、２１，２２…整流回路、２３…加算器、２４…直流電流設定器、２５…加算器、２６…電流調節器、２７…点弧角調整器、２８…電圧検出器、２９…直流電圧設定器、３０…加算器、３１…電流調節器、３２…電極昇降装置、４０…直流アーク炉設備、４１…電流設定値演算回路。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of operating a DC arc furnace facility based on a DC voltage set value for setting an arc voltage and a DC current set value for setting an electrode current.
[0002]
[Prior art]
FIG. 3 is a circuit configuration diagram showing a conventional example of a method of operating this type of DC arc furnace equipment, wherein 1 is a power system such as a commercial power source, and 10 is a DC arc furnace equipment.
The DC arc furnace facility 10 includes a furnace breaker 11, a furnace transformer 12, a thyristor rectifier 13, an electrode 14, a furnace body 15, a furnace bottom electrode 16, a DC reactor 17, and a melting material 18. Current transformers (CT) 19 and 20, rectifier circuits 21 and 22, adder 23, DC current setter 24, adder 25, current regulator 26, and firing angle regulator. 27, a voltage detector 28, a DC voltage setter 29, an adder 30, a current regulator 31, and an electrode lifting / lowering device 32.
[0003]
In FIG. 3, first, when the furnace circuit breaker 11 is turned on by a starting circuit (not shown), the starting circuit is ignited in a state where the electrode 14 and the molten material 18 are in contact with each other via the electrode lifting device 32. An activating current is supplied to the electrode 14 from the thyristor rectifier 13 via the angle adjuster 27, and the electrode 14 is raised via the starting current and the electrode elevating device 32, whereby an arc is generated between the electrode 14 and the molten material 18. And the start-up of the DC arc furnace facility 10 is completed.
[0004]
Next, when the start-up described above is completed, the operator operates the DC current setting unit 24 and the DC voltage setting unit 29, and the DC voltage setting value of the operated DC voltage setting unit 29 and the voltage detector 28 are operated. The adder 30 determines the deviation of the arc voltage between the electrode 14 and the furnace bottom electrode 16, and the voltage regulator 31 outputs the amount of raising / lowering at which the deviation becomes zero. While controlling the arc voltage to a desired value by adjusting the position of the electrode 14, the DC current set value of the operated DC current setter 24 and the secondary currents of the CTs 19 and 20 are simultaneously converted into the rectifier circuit 21, 22 is converted into a direct current, and a deviation from the electrode current obtained by adding these direct currents by an adder 23 is obtained by an adder 25, and the current regulator 26 outputs a firing angle command value at which this deviation becomes zero. This firing angle command value The ignition angle adjuster 27 outputs the gate signal of the ignition phase based on the output, and this gate signal is supplied to each thyristor constituting the thyristor rectifier 13 so that the power transformer 1 and the thyristor rectifier are supplied from the power system 1. The electrode current of the electrode 14 obtained through the device 13 and the DC reactor 17 is controlled to a desired value, and the melting material 18 in the furnace body 15 continues to melt.
[0005]
[Problems to be solved by the invention]
In the above-described conventional DC arc furnace facility 10, the operator operates the DC current setting unit 24 and the DC voltage setting unit 29 each time in order to maintain the optimal melting state of the melting material 18.
However, when the power system 1 is a power system with little surplus power, a new input power value of the DC arc furnace facility 10 that is the product of the set values of the DC current setting device 24 and the DC voltage setting device 29 that have been operated as described above. If the difference between W 1 and the input power value W 0 immediately before the operation is large, the voltage of the power system 1 greatly fluctuates based on this operation, and this voltage fluctuation is caused by the DC arc furnace equipment 10 and the power system 1. There was a problem of adversely affecting other power equipment.
[0006]
An object of the present invention is to provide a method of operating a DC arc furnace facility that solves the above problems.
[0007]
[Means for Solving the Problems]
The present invention adjusts the firing angle of the thyristor constituting the thyristor rectifier based on the DC current setting value while controlling the arc voltage by adjusting the lifting / lowering amount of the electrode lifting device based on the DC voltage setting value. In the DC arc furnace equipment operated by controlling the electrode current by
When an operation for setting either one or both of the DC voltage set value and the DC current set value to a new value is performed, the DC arc furnace equipment is renewed based on the DC voltage set value and the DC current set value. A new input power value W 1 is calculated, and this new input power value W 1 is a predetermined change width value (W 0 ± Δw) with respect to the input power value W 0 of the DC arc furnace facility immediately before the operation is performed. when in the range of, drove direct current arc furnace facilities on the basis of the above corresponding to an input power value W 1 DC voltage setting value and the DC current set value, the input power value W 1 is the variation width value ( W 0 + Δw) is exceeded, a DC current setting value at which the input power value becomes W 0 + Δw is calculated, and the DC arc is calculated based on the calculated DC current setting value and the DC voltage setting value. Predetermined time of operation of furnace equipment Rolling, and this after the expiration of time driving a direct current arc furnace facilities on the basis of the DC current set value and the DC voltage setting value corresponding to the input power value W 1, the input power value W 1 is the When the change width value is less than (W 0 −Δw), a DC current set value at which the input power value becomes W 0 −Δw is calculated, and based on the calculated DC current set value and the DC voltage set value. the DC arc furnace facility operated a predetermined time, this is after the time to drive a direct current arc furnace facilities on the basis of said DC voltage set value and the DC current set value corresponding to the input power value W 1 .
[0008]
According to the present invention, the new input power value W 1 of the DC arc furnace equipment, which is the product of the DC current set value and the DC voltage set value set by the operator, and the input power value W 0 immediately before the operation is performed. When the DC arc furnace equipment is operated for a predetermined time at an input power value (W 0 ± Δw) that results in a voltage fluctuation allowed by the power system for a predetermined time, and then the DC arc furnace equipment is It is to be operated at an input power value W 1.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a circuit configuration diagram showing an embodiment of a method for operating a DC arc furnace facility according to the present invention. Components having the same functions as those of the conventional circuit shown in FIG. Is omitted.
That is, the DC arc furnace facility 40 shown in FIG. 1 includes a furnace circuit breaker 11, a furnace transformer 12, a thyristor rectifier 13, an electrode 14, a furnace body 15, a furnace bottom electrode 16, a DC reactor 17, a melting material 18, Current transformers 19 and 20, rectifier circuits 21 and 22, adder 23, DC current setter 24, adder 25, current adjuster 26, firing angle adjuster 27, voltage detector 28, DC voltage setter 29, an adder 30, a current adjuster 31, and an electrode lifting / lowering device 32 are provided with a current set value calculation circuit 41.
[0010]
The operation method of the DC arc furnace facility 40 will be described below with reference to the flowchart of the operation of the current set value calculation circuit 41 shown in FIG.
First, the procedure for completing the start-up of the DC arc furnace facility 40 is the same as the procedure in the DC arc furnace facility 10 shown in FIG.
Next, when the DC arc furnace facility 40 is started up, the current set value calculation circuit 41 sets the input power value at the time of startup as the initial value of W 0 , and sets the reset state of the timer flag described later as the initial value. The operation shown in is started.
[0011]
In FIG. 2, when this flowchart is entered for the first time, the timer flag is in the reset state (step S11, branch N), so the set values of the DC current setting unit 24 and the DC voltage setting unit 29 operated by the operator are set. Reading (step S12), and since this reading value depends on the above operation (step S13, branch Y), the process proceeds to step S14.
[0012]
In step S14, it obtains the product of the set value of the DC voltage setting unit 29 and the set value of the direct current setter 24 read in step S12, which as the current input power value W 1, proceeds to step 15.
In step S15, if in comparing the input power value W 1 input power value W stored as 0 determined, the absolute value is within a predetermined value ([Delta] w) of the difference step S14 (branch ▲ 1 ▼), and stores the input power value W 1 as the new input power value W 0 (step S16), and the set value of the direct current setter 24 is output to the adder 25 as a direct current setting value read in step S12 ( In step S17), the DC arc furnace facility 40 is operated based on the DC current set value output from the current set value calculation circuit 41 and the DC voltage set value output from the DC voltage setter 29.
[0013]
In step S15, when being exceeded variation width value based on the input power value W 0 of input power value W 1 is stored determined in step S14 the (W 0 + [Delta] w) (branch ▲ 2 ▼), input power value adder 25 but a direct current setting value that is the W 0 + [Delta] w, calculated from the set value of the DC voltage setting unit 29 read in step S12 and the (W 0 + Δw), the calculated value as a DC current set value (Step S18), the timer is started (step S19), and since this timer has not passed the predetermined time (step S20, branch N), the timer flag is set because the timer is being started. (Step S21), the DC arc furnace equipment 40 operates based on the DC current set value output from the current set value calculation circuit 41 and the DC voltage set value output from the DC voltage setter 29. It takes place.
[0014]
In step S15, when less than the variation width value based on the input power value W 0 of input power value W 1 is stored obtained in step S14 (W 0 -Δw) (branched ▲ 3 ▼), input power value is the W 0 direct current setting value to be -Derutadaburyu, calculated from the set value of the DC voltage setting unit 29 read in step S12 and the (W 0 -Δw), the adder 25 the calculated value as a DC current set value (Step S22), the timer is started (step S19), and since this timer has not passed the predetermined time (step S20, branch N), the timer flag is set because the timer is being started. The DC arc furnace equipment 40 is operated based on the DC current set value output from the current set value calculation circuit 41 and the DC voltage set value output from the DC voltage setter 29. .
[0015]
In FIG. 2, it is in a state where the timer flag is set at step S11 (branch Y), the last or input power value W 1 and the stored input power value W that it asked the previous round in step S14 Since the absolute value of the difference from 0 exceeds the predetermined value (Δw), the operation is in the above-described step S18 or step S22, so the process proceeds to step S20. At this time, the timer has passed a predetermined time. if I (branch Y), the timer is stopped, resets the timer flag (step S23), stores the input power value W 1 as the new input power value W 0 (step S16), and the DC current read in step S12 The set value of the setter 24 is output as a DC current set value to the adder 25 (step S17), and the DC arc furnace equipment 40 outputs the direct current set value calculation circuit 41 that outputs the direct current. A current setting value, operation based on the is performed and the DC voltage setting value DC voltage setting unit 29 outputs.
[0016]
Further, in FIG. 2, the DC arc furnace facility 40 is operated based on the DC current set value output from the current current set value calculation circuit 41 and the DC voltage set value output from the DC voltage setter 29, and an optimum melting state is obtained. If it is maintained, the timer flag is also in the reset state (step S11, branch N), and the set value is changed by the operator (step S13, branch N). In step 24, the DC read in step S12 The product of the setting value of the current setting device 24 and the setting value of the DC voltage setting device 29 is obtained, and this is set as the input power value W 0 , the process proceeds to step 17, and in step S 17 the DC current setting device 24 read in step S 12. The set value is output to the adder 25 as a DC current set value, and the DC arc furnace equipment 40 outputs the DC current set value output from the current set value calculation circuit 41 and the DC The operation based on the DC voltage set value output from the voltage setter 29 is performed.
[0017]
【The invention's effect】
According to the present invention, in order to maintain the optimum melting state of the melting material of the DC arc furnace equipment, a new DC arc furnace equipment that is a product of the DC current set value and the DC voltage set value set by the operator is provided. when the difference between the input power value immediately before being input power values W 1 and the manipulation is large, a direct current arc furnace facility operated a predetermined time an input power value of a predetermined time power system is voltage variation permitted Thereafter, by operating the DC arc furnace facility at the input power value W 1 , the DC arc furnace facility is particularly suitable for an electric power system having a small surplus power.
[Brief description of the drawings]
FIG. 1 is a circuit configuration diagram showing an embodiment of a method of operating a DC arc furnace facility according to the present invention. FIG. 2 is a flowchart for explaining the operation of FIG. 1. FIG. 3 is a circuit showing a method of operating a conventional DC arc furnace facility. Configuration diagram [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Electric power system, 10 ... DC arc furnace equipment, 11 ... Breaker for furnace, 12 ... Transformer for furnace, 13 ... Thyristor rectifier, 14 ... Electrode, 15 ... Furnace body, 16 ... Furnace bottom electrode, 17 ... DC Reactor, 18 ... melted material, 19, 20 ... current transformer for instrument, 21, 22 ... rectifier circuit, 23 ... adder, 24 ... DC current setter, 25 ... adder, 26 ... current regulator, 27 ... point Arc angle adjuster, 28 ... voltage detector, 29 ... DC voltage setter, 30 ... adder, 31 ... current adjuster, 32 ... electrode lifting device, 40 ... DC arc furnace equipment, 41 ... current set value calculation circuit.

Claims (1)

直流電圧設定値に基づいて電極昇降装置の昇降量を調整することによりアーク電圧を制御しつつ、直流電流設定値に基づいてサイリスタ整流装置を構成するサイリスタの点弧角を調整することにより電極電流を制御して運転される直流アーク炉設備において、
前記直流電圧設定値又は直流電流設定値のいずれか一方若しくは双方を新たな値に設定する操作が行われたときに、この直流電圧設定値と直流電流設定値とにより前記直流アーク炉設備の新たな投入電力値Ｗ１ を演算し、
この新たな投入電力値Ｗ１ が前記操作を行う直前の前記直流アーク炉設備の投入電力値Ｗ０ に対して所定の変化幅値（Ｗ０ ±Δｗ）の範囲内のときには、この投入電力値Ｗ１ に対応した前記直流電圧設定値と直流電流設定値とに基づいて該直流アーク炉設備を運転し、
前記投入電力値Ｗ１ が前記変化幅値（Ｗ０ ＋Δｗ）を超過しているときには、投入電力値が前記Ｗ０ ＋Δｗになる直流電流設定値を演算し、この演算された直流電流設定値と前記直流電圧設定値とに基づいて前記直流アーク炉設備を予め定めた時間運転し、この時間を経過した後は前記投入電力値Ｗ１ に対応した前記直流電圧設定値と直流電流設定値とに基づいて該直流アーク炉設備を運転し、
前記投入電力値Ｗ１ が前記変化幅値（Ｗ０ −Δｗ）未満のときには、投入電力値が前記Ｗ０ −Δｗになる直流電流設定値を演算し、この演算された直流電流設定値と前記直流電圧設定値とに基づいて前記直流アーク炉設備を予め定めた時間運転し、この時間経過した後は前記投入電力値Ｗ１ に対応した前記直流電圧設定値と直流電流設定値とに基づいて該直流アーク炉設備を運転することを特徴とする直流アーク炉設備の運転方法。While controlling the arc voltage by adjusting the lifting amount of the electrode lifting device based on the DC voltage setting value, the electrode current by adjusting the firing angle of the thyristor constituting the thyristor rectifier device based on the DC current setting value In a DC arc furnace facility operated by controlling
When an operation for setting either one or both of the DC voltage set value and the DC current set value to a new value is performed, the DC arc furnace equipment is renewed based on the DC voltage set value and the DC current set value. Calculate the correct input power value W 1 ,
The DC arc furnace facilities of an input power value W a predetermined variation width value for 0 immediately before the new input power value W 1 performs the operation at the time of the range of (W 0 ± [Delta] w), the input power value Operating the DC arc furnace facility based on the DC voltage setting value and the DC current setting value corresponding to W 1 ;
When the input power value W 1 exceeds the change width value (W 0 + Δw), a DC current set value at which the input power value becomes the W 0 + Δw is calculated, and the calculated DC current set value and the DC voltage the DC arc furnace facility operated a predetermined time based on the set value, after the lapse of this time and the DC voltage setting value corresponding to the input power value W 1 and DC current set value Operating the DC arc furnace equipment based on
When the input power value W 1 is less than the change width value (W 0 −Δw), a DC current set value at which the input power value becomes the W 0 −Δw is calculated, and the calculated DC current set value and the on the basis of the DC voltage set value predetermined time operating the DC arc furnace facility, the time elapsed after the based on the DC current set value and the DC voltage setting value corresponding to the input power value W 1 A method for operating a DC arc furnace facility, comprising operating the DC arc furnace facility.
JP00205898A 1998-01-08 1998-01-08 Operation method of DC arc furnace equipment Expired - Fee Related JP3627491B2 (en)

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