JP6713942B2 - Excitation current suppressor and power switchgear - Google Patents

Excitation current suppressor and power switchgear Download PDF

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JP6713942B2
JP6713942B2 JP2017048447A JP2017048447A JP6713942B2 JP 6713942 B2 JP6713942 B2 JP 6713942B2 JP 2017048447 A JP2017048447 A JP 2017048447A JP 2017048447 A JP2017048447 A JP 2017048447A JP 6713942 B2 JP6713942 B2 JP 6713942B2
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JP2018152272A (en
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森　智仁
智仁 森
綾 山本
綾 山本
健次 亀井
健次 亀井
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Mitsubishi Electric Corp
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Description

本発明は、変圧器への電源投入時に発生する励磁突入電流を抑制する励磁突入電流抑制装置および電力開閉装置に関するものである。 The present invention relates to an exciting inrush current suppressing device and an electric power switchgear for suppressing an exciting inrush current generated when a power source of a transformer is turned on.

三相変圧器への三相電源の投入が行われる電力開閉装置では、三相電源の投入および遮断を行う三相遮断器が設けられている。このような電力開閉装置において、三相変圧器への三相電源の投入の際に発生する励磁突入電流を抑制する励磁突入電流抑制装置が用いられる場合がある。励磁突入電流抑制装置が励磁突入電流を抑制する方式の一つに、三相電源の特定位相において三相遮断器に三相電源を投入させる位相制御投入方式が挙げられる。 In a power switchgear in which a three-phase power is turned on to a three-phase transformer, a three-phase circuit breaker for turning on and off the three-phase power is provided. In such a power switchgear, an exciting inrush current suppressing device that suppresses an exciting inrush current generated when a three-phase power source is turned on to a three-phase transformer may be used. One of the methods by which the exciting inrush current suppressing device suppresses the exciting inrush current is a phase control closing method in which the three-phase circuit breaker turns on the three-phase power at a specific phase of the three-phase power.

励磁突入電流は、三相電源の遮断時に変圧器の鉄心に残留した残留磁束と、三相電源の投入時の位相によって生じる定常磁束との差の絶対値が大きい場合に発生しやすい。そこで、特許文献１に記載の励磁突入電流抑制装置は、三相電源が遮断されたときに過渡的に変化する各相の端子電圧を変圧器電圧計測手段で計測する。過渡的に変化した電圧を残留磁束演算手段によって時間積分することで、変圧器の鉄心の残留磁束を演算する。算出された残留磁束と定常磁束とが一致する位相で遮断器が制御されて三相電源が投入される。 The exciting inrush current is likely to occur when the absolute value of the difference between the residual magnetic flux remaining in the iron core of the transformer when the three-phase power supply is cut off and the steady magnetic flux generated by the phase when the three-phase power supply is turned on is large. Therefore, the excitation inrush current suppressing device described in Patent Document 1 measures the terminal voltage of each phase that transiently changes when the three-phase power supply is cut off by the transformer voltage measuring means. The residual magnetic flux of the transformer's iron core is calculated by time-integrating the transiently changed voltage by the residual magnetic flux calculation means. The circuit breaker is controlled at the phase where the calculated residual magnetic flux and the steady magnetic flux match, and the three-phase power supply is turned on.

特開２０１３−６２１９６号公報JP, 2013-62196, A

しかしながら、従来の位相制御投入方式では、三相電源を遮断したときの変圧器の端子電圧を計測する必要があるため、端子電圧を計測する電圧測定器が電力開閉装置に設けられていない場合には位相制御投入を行うことが難しいという問題があった。 However, in the conventional phase control closing method, it is necessary to measure the terminal voltage of the transformer when the three-phase power supply is cut off.Therefore, when the voltage measuring device that measures the terminal voltage is not provided in the power switchgear, Has a problem that it is difficult to perform phase control.

本発明は、上記に鑑みてなされたものであって、端子電圧を計測せずに位相制御投入を行うことができる励磁突入電流抑制装置を得ることを目的とする。 The present invention has been made in view of the above, and an object of the present invention is to provide an exciting inrush current suppressing device that can perform phase control closing without measuring a terminal voltage.

上述した課題を解決し、目的を達成するために、本発明は、三相変圧器への三相電源の投入後に発生する励磁突入電流に基づいて、三相電源の開極時の三相変圧器の鉄心に残留する磁束である残留磁束を算出する残留磁束算出手段と、三相電源の位相の変化によって生じる定常磁束と残留磁束との差分である投入磁束誤差を算出する誤差算出手段と、投入磁束誤差に基づいて三相変圧器に三相電源を投入する位相である目標閉極位相を決定する目標閉極位相算出手段と、目標位相で三相変圧器に三相電源を投入させる制御手段と、を備える。 In order to solve the above-mentioned problems and to achieve the object, the present invention provides a three-phase transformer when the three-phase power supply is opened, based on an exciting inrush current generated after the three-phase transformer is turned on. Residual magnetic flux calculating means for calculating the residual magnetic flux that is the magnetic flux remaining in the iron core of the container, and error calculating means for calculating the closing magnetic flux error that is the difference between the steady magnetic flux and the residual magnetic flux caused by the change in the phase of the three-phase power supply Target closed-pole phase calculating means for determining a target closed-pole phase, which is a phase for applying the three-phase power to the three-phase transformer based on the applied magnetic flux error, and control for turning on the three-phase power to the three-phase transformer at the target phase And means.

本発明にかかる励磁突入電流抑制装置によれば、端子電圧を計測せずに位相制御投入を行うことができるという効果を奏する。 According to the exciting inrush current suppressing device of the present invention, there is an effect that the phase control can be performed without measuring the terminal voltage.

本発明の実施の形態１にかかる電力開閉装置を模式的に示す図The figure which shows typically the electric power switchgear concerning Embodiment 1 of this invention. 三相変圧器の鉄心の残留磁束と励磁突入電流との関係を示す図The figure which shows the relationship between the residual magnetic flux of the iron core of a three-phase transformer, and the magnetizing inrush current. 本発明の実施の形態２にかかる電力開閉装置の概略構成を示す模式図The schematic diagram which shows schematic structure of the power switchgear concerning Embodiment 2 of this invention. 開極位相と残留磁束との関係を示す図Diagram showing the relationship between the opening phase and the residual magnetic flux 開極位相と残留磁束との関係を示す図Diagram showing the relationship between the opening phase and the residual magnetic flux

以下に、本発明の実施の形態にかかる励磁突入電流抑制装置および電力開閉装置を図面に基づいて詳細に説明する。なお、この実施の形態によりこの発明が限定されるものではない。 Hereinafter, an exciting inrush current suppressing device and a power switchgear according to an embodiment of the present invention will be described in detail with reference to the drawings. The present invention is not limited to this embodiment.

実施の形態１．
図１は、本発明の実施の形態１にかかる電力開閉装置を模式的に示す図である。電力開閉装置５０は、三相電源２、三相遮断器３、三相変圧器１、電圧測定器１７、計器用変流器２１、および励磁突入電流抑制装置４０を備える。励磁突入電流抑制装置４０は、残留磁束算出手段６、投入磁束誤差算出手段８、目標閉極位相算出手段１３、および制御手段１５を備える。 Embodiment 1.
1 is a diagram schematically showing a power switchgear according to a first embodiment of the present invention. The power switchgear 50 includes a three-phase power supply 2, a three-phase circuit breaker 3, a three-phase transformer 1, a voltage measuring device 17, an instrument current transformer 21, and an exciting inrush current suppressing device 40. The excitation inrush current suppressing device 40 includes a residual magnetic flux calculating means 6, a closing magnetic flux error calculating means 8, a target closed pole phase calculating means 13, and a control means 15.

三相電源２は、Ａ相、Ｂ相およびＣ相の各電源電圧ｙｐａ，ｙｐｂ，ｙｐｃを発生して、三相遮断器３の接触子３ａ，３ｂ，３ｃにそれぞれ出力する。三相遮断器３の接触子３ａ，３ｂ，３ｃは三相変圧器１に接続される。三相遮断器３の接触子３ａ，３ｂ，３ｃは開閉可能な接点である。接触子３ａ，３ｂ，３ｃが閉じることで三相変圧器１への三相電源２の投入が行われる。また、接触子３ａ，３ｂ，３ｃが開くことで三相変圧器１への三相電源２の遮断が行われる。なお、以下の説明において、接触子３ａ，３ｂ，３ｃが閉じることを閉極ともいい、接触子３ａ，３ｂ，３ｃが開くことを開極ともいう。 The three-phase power supply 2 generates respective power supply voltages ypa, ypb, ypc of the A-phase, B-phase and C-phase and outputs them to the contacts 3a, 3b, 3c of the three-phase circuit breaker 3, respectively. The contacts 3a, 3b, 3c of the three-phase circuit breaker 3 are connected to the three-phase transformer 1. The contacts 3a, 3b, 3c of the three-phase circuit breaker 3 are contacts that can be opened and closed. By closing the contacts 3a, 3b, 3c, the three-phase power supply 2 is turned on to the three-phase transformer 1. Further, the contacts 3a, 3b, 3c are opened, so that the three-phase power supply 2 to the three-phase transformer 1 is shut off. In the following description, closing the contacts 3a, 3b, 3c is also referred to as closing pole, and opening the contacts 3a, 3b, 3c is also referred to as opening pole.

三相遮断器３の接触子３ａ，３ｂ，３ｃは、制御手段１５からの開極制御信号２０ａおよび閉極制御信号２０ｂに応答して、連動して実質的に３つ同時に開極および閉極される。三相遮断器３は、閉極制御信号２０ｂに応答して閉極を行った際に、三相電源２の投入時の位相である投入位相を示す投入位相信号４を残留磁束算出手段６に向けて出力する。 The contacts 3a, 3b, 3c of the three-phase circuit breaker 3 are responsive to the opening control signal 20a and the closing control signal 20b from the control means 15 and are interlocked to substantially three simultaneously opening and closing. To be done. When the three-phase circuit breaker 3 is closed in response to the closing control signal 20b, the three-phase circuit breaker 3 outputs to the residual magnetic flux calculating means 6 a closing phase signal 4 indicating a closing phase which is a phase when the three-phase power supply 2 is turned on. To output.

電圧測定器１７は、基準相であるＡ相の対地電圧を測定して、測定結果を示す電源電圧信号１８を制御手段１５に出力する。なお、電力開閉装置５０では、基準相であるＡ相の対地電圧を測定する電圧測定器１７は設けられているが、Ｂ相、Ｃ相の対地電圧を測定する測定器は設けられていない。 The voltage measuring device 17 measures the ground voltage of the A phase, which is the reference phase, and outputs the power supply voltage signal 18 indicating the measurement result to the control means 15. The power switchgear 50 is provided with the voltage measuring device 17 for measuring the ground voltage of the A phase, which is the reference phase, but is not provided with the measuring device for measuring the ground voltage of the B phase and the C phase.

電流計測器である計器用変流器２１は、各相の電流を計測する計器用変流器２１ａ，２１ｂ，２１ｃを有する。計器用変流器２１は、各相に流れる電流を測定して、測定結果を示す主回路電流信号５を残留磁束算出手段６に向けて出力する。なお、計器用変流器２１と残留磁束算出手段６との間に二次変流器を設けて、二次変流器から主回路電流信号５が出力されるように構成してもよい。 The measuring instrument current transformer 21 which is a current measuring device has measuring instrument current transformers 21a, 21b and 21c for measuring the currents of the respective phases. The instrument current transformer 21 measures the current flowing in each phase and outputs a main circuit current signal 5 indicating the measurement result to the residual magnetic flux calculation means 6. A secondary current transformer may be provided between the instrument current transformer 21 and the residual magnetic flux calculating means 6 so that the main circuit current signal 5 is output from the secondary current transformer.

残留磁束算出手段６は、入力された主回路電流信号５に基づいて、閉極前に三相変圧器１の鉄心に残留していた残留磁束を算出する。これは、前回の開極時に三相変圧器１の鉄心に残留した残留磁束を算出すると換言できる。図２は、三相変圧器の鉄心の残留磁束と励磁突入電流との関係を示す図である。 The residual magnetic flux calculating means 6 calculates the residual magnetic flux remaining in the iron core of the three-phase transformer 1 before closing the pole based on the input main circuit current signal 5. This can be rephrased to calculate the residual magnetic flux remaining in the iron core of the three-phase transformer 1 at the previous opening. FIG. 2 is a diagram showing the relationship between the residual magnetic flux of the iron core of the three-phase transformer and the magnetizing inrush current.

三相遮断器３への三相電源２の投入時の投入時間をｔ０とし、その直後に発生する励磁突入電流の発生時間をｔ１とし、残留磁束をΔφとし、三相変圧器１の鉄心の飽和磁束閾値をφ０とし、三相電源２の位相の変化によって生じる電源側の磁束波形である定常磁束波形をφ（ｔ）とした場合、三相電源２の投入後の経過時間ｔ後の磁束波形Φ（ｔ）は下記の数式（１）で表される。なお、定常磁束は、三相電源２の位相の変化によって生じる磁束である。
Φ（ｔ）＝φ（ｔ）＋Δφ−φ（ｔ０） （１） When the turn-on time when the three-phase power supply 2 is turned on to the three-phase circuit breaker 3 is t 0 , the generation time of the exciting inrush current generated immediately after that is t 1 , the residual magnetic flux is Δφ, and the three-phase transformer 1 When the saturation magnetic flux threshold of the iron core is φ 0 and the steady magnetic flux waveform which is the magnetic flux waveform on the power source side caused by the change in the phase of the three-phase power source 2 is φ(t), the elapsed time t after the three-phase power source 2 is turned on is t. The subsequent magnetic flux waveform Φ(t) is expressed by the following mathematical expression (1). The steady magnetic flux is a magnetic flux generated by a change in the phase of the three-phase power supply 2.
Φ(t)=φ(t)+Δφ−φ(t 0 ) (1)

ここで、定常磁束波形φ（ｔ）は、以下の数式（２）で表される。磁束波高値を１ＰＵとして規格化した。
φ（ｔ）＝ｓｉｎ（ωｔ） ［ω＝２πｆ（ｆ：周波数）］ （２） Here, the steady magnetic flux waveform φ(t) is represented by the following mathematical expression (2). The magnetic flux peak value was standardized as 1 PU.
φ(t)=sin(ωt) [ω=2πf (f: frequency)] (2)

発生時間ｔ１の時に三相変圧器１の鉄心が飽和してインラッシュ電流が発生する場合、
Φ（ｔ１）＝φ０ （３）
となる。 When the iron core of the three-phase transformer 1 is saturated and an inrush current is generated at the generation time t 1 ,
Φ(t 1 )=Φ 0 (3)
Becomes

上記数式（１）、上記数式（２）および上記数式（３）により、三相変圧器１の鉄心の残留磁束Δφは、下記の数式（４）で算出される。
Δφ＝φ０−φ（ｔ１） ＋φ（ｔ０）
＝φ０ − ｓｉｎ（ωｔ１）＋ｓｉｎ（ωｔ０） （４） The residual magnetic flux Δφ of the iron core of the three-phase transformer 1 is calculated by the following mathematical expression (4) using the mathematical expression (1), the mathematical expression (2), and the mathematical expression (3).
Δφ=φ 0 −φ(t 1 )+φ(t 0 )
=φ 0 −sin(ωt 1 )+sin(ωt 0 )(4)

すなわち、投入時間ｔ０と発生時間ｔ１とを把握することで、その開極位相での残留磁束が求められる。開極位相と残留磁束との関係が求められた後は、同一の開極位相で開極制御を行うことで、三相変圧器１の鉄心の残留磁束Δφは上記数式（４）で算出された値であると推定される。本実施の形態１では、閉極位相は基本的に固定値とされている。したがって、上記数式（４）に基づいて残留磁束Δφが算出されれば、その後の開極時にも同じ値の残留磁束Δφが三相変圧器１の鉄心に残留しているものと推定することができる。ここで算出された残留磁束値に基づいて目標位相を設定して投入位相制御が実施される。 That is, by grasping the closing time t 0 and the generation time t 1 , the residual magnetic flux in the open phase is obtained. After the relationship between the open pole phase and the residual magnetic flux is obtained, the residual flux Δφ of the iron core of the three-phase transformer 1 is calculated by the above formula (4) by performing the open pole control with the same open phase. It is estimated that In the first embodiment, the closed pole phase is basically a fixed value. Therefore, if the residual magnetic flux Δφ is calculated based on the above equation (4), it can be estimated that the residual magnetic flux Δφ having the same value remains in the iron core of the three-phase transformer 1 even after the subsequent opening of the pole. it can. The closing phase control is executed by setting the target phase based on the residual magnetic flux value calculated here.

残留磁束算出手段６は、入力された主回路電流信号５に基づいて発生時間ｔ１を把握する。また、残留磁束算出手段６は、投入位相信号４の入力に基づいて投入時間ｔ０を把握する。残留磁束算出手段６は、算出された残留磁束を示す残留磁束信号７を投入磁束誤差算出手段８に向けて出力する。 The residual magnetic flux calculating means 6 grasps the generation time t 1 based on the input main circuit current signal 5. Further, the residual magnetic flux calculation means 6 grasps the closing time t 0 based on the input of the closing phase signal 4. The residual magnetic flux calculating means 6 outputs a residual magnetic flux signal 7 indicating the calculated residual magnetic flux to the closing magnetic flux error calculating means 8.

ここで、三相遮断器３の各接触子３ａ，３ｂ，３ｃは互いに同一のプレアーク特性および閉極時間ばらつき特性を有する。なお、以下の説明において、接触子３ａ，３ｂ，３ｃを区別しないときには、単に、接触子または三相遮断器３という。三相遮断器３の接触子３ａ，３ｂ，３ｃはそれぞれ、入力される閉極制御信号２０ｂに応答して、機械的な動作時間が経過した後に閉極する。閉極制御信号２０ｂが入力されてから閉極するまでの機械的な動作時間を閉極時間という。閉極時間は、三相遮断器３の周囲温度、操作油圧、制御電圧および休止時間に依存する。また、閉極前に先行放電によって接触子に主回路電流が流れ始めることが知られている。この先行放電はプレアークと呼ばれており、主回路電流が流れ始めるタイミングを投入といい、接触子のプレアークの特性をプレアーク特性という。 Here, the contacts 3a, 3b, 3c of the three-phase circuit breaker 3 have the same pre-arc characteristic and closing-pole time variation characteristic. In the following description, when the contacts 3a, 3b, 3c are not distinguished, they are simply referred to as contacts or three-phase circuit breaker 3. The contacts 3a, 3b, 3c of the three-phase circuit breaker 3 are closed in response to the input closing control signal 20b after the mechanical operation time has elapsed. The mechanical operation time from the input of the closing control signal 20b to the closing is called the closing time. The closing time depends on the ambient temperature of the three-phase circuit breaker 3, the operating oil pressure, the control voltage and the rest time. Further, it is known that the main circuit current starts to flow in the contact due to the preceding discharge before the closing. This preceding discharge is called pre-arc, the timing at which the main circuit current starts to flow is called input, and the pre-arc characteristic of the contact is called pre-arc characteristic.

さらに、接触子は機械的な動作ばらつきを有しており、閉極制御信号２０ｂが入力されたときに、実際に接触子が閉極するタイミングの確率分布は、閉極制御信号２０ｂが入力されたタイミングに対応する閉極時間を中心としてばらつく正規分布になる。この接触子の閉極時間のばらつきの特性が、閉極時間ばらつき特性である。接触子３ａ，３ｂ，３ｃは、同一の閉極時間ばらつき特性を有する。同様に、接触子３ａ，３ｂ，３ｃの開極時間にもばらつき特性があり、これを開極時間ばらつき特性という。 Further, the contacts have mechanical operation variations, and when the closing control signal 20b is input, the probability distribution of the timing at which the contacts are actually closed is the closing control signal 20b input. The normal distribution fluctuates around the closed pole time corresponding to the timing. The characteristic of the variation in the closing time of the contact is the variation characteristic of the closing time. The contacts 3a, 3b, 3c have the same closing-pole time variation characteristics. Similarly, the contact opening times of the contacts 3a, 3b, 3c also have a variation characteristic, which is called an opening time variation characteristic.

投入磁束誤差算出手段８は、三相変圧器１の各相の残留磁束、三相遮断器３のプレアーク特性および閉極時間ばらつき特性に基づいて、閉極位相の投入磁束誤差を相ごとに算出する。投入磁束誤差は、三相電源２の投入時間ｔ０時の定常磁束値と残留磁束値との差の絶対値である。投入磁束誤差算出手段８は、算出した投入磁束誤差を示す投入磁束誤差信号１２を目標閉極位相算出手段１３に出力する。 The closing magnetic flux error calculating means 8 calculates the closing magnetic flux error for each phase based on the residual magnetic flux of each phase of the three-phase transformer 1, the pre-arc characteristic of the three-phase circuit breaker 3, and the closing time variation characteristic. To do. The closing magnetic flux error is the absolute value of the difference between the steady magnetic flux value and the residual magnetic flux value at the closing time t 0 of the three-phase power supply 2. The closing flux error calculating means 8 outputs a closing flux error signal 12 indicating the calculated closing flux error to the target closed pole phase calculating means 13.

目標閉極位相算出手段１３は、投入磁束誤差に基づいて目標閉極位相を決定する。定常磁束には、相ごとに位相のずれがあるので、各相の投入磁束誤差の平均値が最も小さくなるように目標閉極位相を決定してもよい。目標閉極位相算出手段１３は、目標閉極位相を示す目標閉極位相信号１４を制御手段１５に出力する。なお、全ての接触子３ａ，３ｂ，３ｃを実質的に同時に閉極するように制御しても、Ｂ相及びＣ相の各閉極時間はそれぞれ、Ａ相の閉極時間に対して閉極時間平均値のずれ量だけずれる。目標閉極位相算出手段１３は、この閉極時間平均値のずれ量を考慮して目標閉極位相を決定してもよい。 The target closed pole phase calculation means 13 determines the target closed pole phase based on the applied magnetic flux error. Since the stationary magnetic flux has a phase shift for each phase, the target closed pole phase may be determined so that the average value of the applied magnetic flux errors of each phase becomes the smallest. The target closed pole phase calculation means 13 outputs a target closed pole phase signal 14 indicating the target closed pole phase to the control means 15. Even if all the contacts 3a, 3b, 3c are controlled so as to be closed at substantially the same time, the B-phase and C-phase closing times are different from the A-phase closing time. It deviates by the amount of deviation of the time average value. The target closed-pole phase calculating means 13 may determine the target closed-pole phase in consideration of the deviation amount of the closing-pole time average value.

制御手段１５は、図示を省略した上位の制御装置から開極指令１９ａが入力されると、固定値である目標開極位相で開極するように開極制御信号２０ａを三相遮断器３に向けて出力する。 When an opening command 19a is input from a higher-order control device (not shown), the control means 15 sends an opening control signal 20a to the three-phase circuit breaker 3 so as to open the target opening phase which is a fixed value. To output.

制御手段１５は、図示を省略した上位の制御装置から閉極指令１９ｂが入力されると、目標閉極位相算出手段１３が算出した目標閉極位相で閉極するように閉極制御信号２０ｂを三相遮断器３に向けて出力する。 When the closing command 19b is input from a higher-order control device (not shown), the control means 15 outputs the closing control signal 20b so as to close the target closing phase calculated by the target closing phase calculating means 13. Output to the three-phase circuit breaker 3.

ここで、励磁突入電流は、図２に示すように三相電源２の投入時間ｔ０の後に、三相変圧器１の鉄心での磁束が、その鉄心の飽和磁束閾値φ０を超えた場合に発生する。投入時間ｔ０後の磁束の波形は、三相変圧器１の鉄心に残留した残留磁束と投入時間ｔ０時の定常磁束との差の絶対値を定常磁束波形に加えた波形となる。したがって、三相変圧器１の鉄心に残留した残留磁束と、投入時間ｔ０時の定常磁束との差、すなわち投入磁束誤差が大きい場合に励磁突入電流が発生しやすくなる。したがって、相ごとの投入磁束誤差の平均値が最も小さくなるように目標閉極位相を決定することで、励磁突入電流の発生を抑制する位相制御投入を行うことができる。 Here, as shown in FIG. 2, when the magnetic flux in the iron core of the three-phase transformer 1 exceeds the saturation magnetic flux threshold value φ 0 of the iron core after the turn-on time t 0 of the three-phase power source 2, as shown in FIG. Occurs in. Magnetic flux waveform after on time t 0 has a waveform obtained by adding the steady-state magnetic flux waveform absolute value of the difference between the steady-state magnetic flux o'clock residual magnetic flux and the input time t 0 remaining in the core of the three-phase transformer 1. Therefore, when the difference between the residual magnetic flux remaining in the iron core of the three-phase transformer 1 and the steady magnetic flux at the closing time t 0 , that is, when the closing magnetic flux error is large, the exciting inrush current is likely to occur. Therefore, by determining the target closed-pole phase so that the average value of the magnetic flux inrush current for each phase is minimized, it is possible to perform the phase control injection that suppresses the generation of the exciting inrush current.

本実施の形態１では、励磁突入電流の発生時間ｔ１と投入時間ｔ０とに基づいて投入磁束誤差が算出される。すなわち、計器用変流器２１によって計測された電流値に基づいて投入磁束誤差が算出されるので、端子電圧を計測せずに位相制御投入を行うことができる。したがって、投入磁束誤差を算出するために電力開閉装置５０に電圧を計測する手段を設ける必要がない。なお、電力開閉装置は、計器用変流器を備えることが一般的である。したがって、電圧を計測する手段が設けられていない電力開閉装置であっても、上述した励磁突入電流抑制装置４０を用いることで位相制御投入を行って、励磁突入電流の発生を抑制することができる。特に、電圧を計測する手段を増設することが困難である電力開閉装置の場合であっても、励磁突入電流抑制装置４０を用いれば位相制御投入を行うことが可能となる。 In the first embodiment, the closing magnetic flux error is calculated based on the generation time t 1 and the closing time t 0 of the exciting inrush current. That is, since the closing magnetic flux error is calculated based on the current value measured by the instrument current transformer 21, the phase control closing can be performed without measuring the terminal voltage. Therefore, it is not necessary to provide the power switchgear 50 with means for measuring the voltage in order to calculate the applied magnetic flux error. The power switchgear is generally equipped with a current transformer for measuring instruments. Therefore, even in the power switchgear which is not provided with the means for measuring the voltage, it is possible to suppress the generation of the exciting inrush current by performing the phase control by using the exciting inrush current suppressing device 40 described above. .. In particular, even in the case of the power switchgear in which it is difficult to add a means for measuring the voltage, it is possible to perform the phase control closing by using the exciting inrush current suppressor 40.

なお、本実施の形態１にかかる電力開閉装置５０では、残留磁束算出手段６が実際に発生した励磁突入電流の発生時間ｔ１に基づいて残留磁束を算出している。そのため、一度も投入が行われていない電力開閉装置５０では、残留磁束の算出がなされていない。すなわち、電力開閉装置５０が設置されて最初の三相電源２の投入時である初期投入時には残留磁束が不明である。そこで、投入磁束誤差算出手段８は、初期投入時には残留磁束値が０であるとして投入磁束誤差を算出する。これにより、初期投入時にも位相制御投入を行うことが可能となる。 In the power switchgear 50 according to the first embodiment, the residual magnetic flux calculation means 6 calculates the residual magnetic flux based on the time t 1 of the actually generated exciting inrush current. Therefore, the residual magnetic flux is not calculated in the power switchgear 50 that has never been turned on. That is, the residual magnetic flux is unknown when the power switchgear 50 is installed and the three-phase power source 2 is first turned on, that is, when the power is initially turned on. Therefore, the closing magnetic flux error calculating means 8 calculates the closing magnetic flux error assuming that the residual magnetic flux value is 0 at the initial closing. As a result, it becomes possible to perform phase control closing even at the time of initial closing.

また、本実施の形態１では、励磁突入電流の発生時間ｔ１と投入時間ｔ０とに基づいて残留磁束を算出して投入磁束誤差を算出しているが、励磁突入電流の継続時間、すなわち励磁突入電流の発生から収束までの時間に基づいて残留磁束を算出して、投入磁束誤差を算出するように構成してもよい。励磁突入電流の継続時間をΔｔとすれば、残留磁束Δφを算出する数式（４）は、以下の数式（５）で表される。
Δφ＝φ０−ｓｉｎ（ｔａｎ−１（ｓｉｎωΔｔ／（１−ｃｏｓωΔｔ）））＋ｓｉｎ（ωｔ０） （５） Further, in the first embodiment, the residual magnetic flux is calculated based on the exciting inrush current generation time t 1 and the closing time t 0 to calculate the closing flux error. The residual magnetic flux may be calculated based on the time from the generation of the exciting inrush current to the convergence thereof, and the closing magnetic flux error may be calculated. If the duration of the exciting inrush current is Δt, the equation (4) for calculating the residual magnetic flux Δφ is represented by the following equation (5).
Δφ=φ 0 −sin(tan −1 (sin ωΔt/(1-cos ωΔt)))+sin(ωt 0 ) (5)

実施の形態２．
図３は、本発明の実施の形態２にかかる電力開閉装置の概略構成を示す模式図である。図４および図５は、開極位相と残留磁束との関係を示す図である。なお、上記実施の形態１と同様の構成には、同様の符号を付して詳細な説明を省略する。上記実施の形態１では開極位相が固定値である例を示したが、本実施の形態２にかかる電力開閉装置５１は、目標開極位相を補正する目標開極位相設定手段２２を備える。 Embodiment 2.
FIG. 3 is a schematic diagram showing a schematic configuration of the power switchgear according to the second embodiment of the present invention. 4 and 5 are diagrams showing the relationship between the opening phase and the residual magnetic flux. It should be noted that the same components as those in the first embodiment are denoted by the same reference numerals and detailed description thereof will be omitted. Although the above-described first embodiment shows an example in which the opening phase is a fixed value, the power switchgear 51 according to the second embodiment includes the target opening phase setting unit 22 that corrects the target opening phase.

目標開極位相設定手段２２には、残留磁束算出手段６から残留磁束信号７が入力される。また、目標開極位相設定手段２２には、三相遮断器３から開極位相を示す開極位相信号２３が入力される。目標開極位相設定手段２２は、残留磁束信号７が示す残留磁束値と、開極位相信号２３が示す開極位相とから、図４および図５に示すような、開極位相と残留磁束との関係を示すデータを相ごとに生成する。 The residual magnetic flux signal 7 is input from the residual magnetic flux calculating means 6 to the target opening phase setting means 22. Further, the target opening phase setting means 22 receives the opening phase signal 23 indicating the opening phase from the three-phase circuit breaker 3. The target opening phase setting means 22 determines the opening phase and the residual magnetic flux as shown in FIGS. 4 and 5 from the residual magnetic flux value indicated by the residual magnetic flux signal 7 and the opening phase indicated by the opening phase signal 23. Data indicating the relationship of is generated for each phase.

図４および図５に示すように、目標開極位相で三相遮断器３を開極する制御を行った場合、開極時間ばらつきによって実際に開極される位相にはばらつきが生じる。目標開極位相設定手段２２は、ばらつきの範囲内で開極した場合の残留磁束の最小値と最大値との差である残留磁束誤差を相ごとに算出する。目標開極位相設定手段２２は、残留磁束誤差が予め定めた閾値を超えている場合には、開極位相をずらす補正を行って、残留磁束誤差を再度算出する。そして、残留磁束誤差が閾値の範囲内になった場合には、その開極位相を目標開極位相とする。図４に示した目標開極位相で三相遮断器を開極する場合に比べて、図５に示した目標開極位相で三相遮断器を開局する場合のほうが、残留磁束誤差が小さくなっている。目標開極位相設定手段２２は、目標開極位相を示す目標開極位相信号２４を制御手段１５に向けて出力する。制御手段１５は、開極指令１９ａが入力されると、目標開極位相で開極させるように開極制御信号２０ａを三相遮断器３に向けて出力する。 As shown in FIGS. 4 and 5, when the control for opening the three-phase circuit breaker 3 at the target opening phase is performed, the phase that is actually opened varies due to the variation in the opening time. The target opening phase setting means 22 calculates, for each phase, a residual magnetic flux error which is a difference between the minimum value and the maximum value of the residual magnetic flux when the contacts are opened within the variation range. When the residual magnetic flux error exceeds the predetermined threshold value, the target opening phase setting unit 22 performs a correction to shift the opening phase and recalculates the residual magnetic flux error. When the residual magnetic flux error is within the threshold range, the opening phase is set as the target opening phase. The residual magnetic flux error is smaller when the three-phase circuit breaker is opened at the target opening phase shown in FIG. 5 than when the three-phase circuit breaker is opened at the target opening phase shown in FIG. ing. The target opening phase setting means 22 outputs a target opening phase signal 24 indicating the target opening phase to the control means 15. When the opening command 19a is input, the control means 15 outputs an opening control signal 20a to the three-phase circuit breaker 3 so as to open at the target opening phase.

残留磁束誤差が大きいということは、開極時間ばらつきの範囲内で開極位相がずれた場合に、残留磁束算出手段６によって算出された残留磁束と実際の残留磁束との差が大きくなりやすいことを意味する。すなわち、残留磁束算出手段６によって算出された残留磁束に基づいて決定された目標閉極位相で三相遮断器３を閉極させた場合に、投入磁束誤差が大きくなって励磁突入電流が発生する可能性が高くなる。 A large residual magnetic flux error means that the difference between the residual magnetic flux calculated by the residual magnetic flux calculating means 6 and the actual residual magnetic flux is likely to be large when the opening magnetic phase is shifted within the range of the opening time variation. Means That is, when the three-phase circuit breaker 3 is closed at the target closing phase determined based on the residual magnetic flux calculated by the residual magnetic flux calculating means 6, the closing magnetic flux error becomes large and an exciting inrush current is generated. More likely.

本実施の形態２では、目標開極位相設定手段２２によって残留磁束誤差を閾値の範囲内に収めることが可能となるので、開極時間ばらつきを原因とする励磁突入電流の発生を抑制することができる。 In the second embodiment, the target opening phase setting means 22 can keep the residual magnetic flux error within the range of the threshold value, so that it is possible to suppress the occurrence of the exciting inrush current due to the opening time variation. it can.

なお、開極位相と残留磁束との関係を示すデータを生成するには、複数の異なる開極位相での残留磁束を取得する必要がある。例えば、予め開極位相を異ならせて残留磁束を取得して開極位相と残留磁束との関係を示すデータを生成させるように構成してもよい。また、残留磁束誤差が予め設定されていた閾値を超えた場合に、開極位相をずらしていく制御を行うことで、開極位相と残留磁束との関係を示すデータを蓄積するように構成してもよい。 In addition, in order to generate the data indicating the relationship between the opening phase and the residual magnetic flux, it is necessary to acquire the residual magnetic fluxes at a plurality of different opening phases. For example, it may be configured such that the opening phase is changed in advance to obtain the residual magnetic flux and the data indicating the relationship between the opening phase and the residual magnetic flux is generated. Further, when the residual magnetic flux error exceeds a preset threshold value, by performing control to shift the open phase, it is configured to accumulate data indicating the relationship between the open phase and the residual magnetic flux. May be.

また、上記実施の形態１，２では、三相電源２の各相を同時に投入する三相一括型の三相遮断器を例に挙げて説明しているが、相ごとに投入の順番を変える各相操作型の遮断器であってもよい。各相操作型の遮断器の場合には、残留磁束が他の相よりも大きい相に最初に三相電源２が投入される。 In the first and second embodiments, a three-phase batch type three-phase circuit breaker that simultaneously turns on each phase of the three-phase power source 2 has been described as an example, but the turn-on order is changed for each phase. It may be a circuit breaker of each phase operation type. In the case of the circuit breaker of each phase operation type, the three-phase power supply 2 is first turned on in the phase in which the residual magnetic flux is larger than the other phases.

以上の実施の形態に示した構成は、本発明の内容の一例を示すものであり、別の公知の技術と組み合わせることも可能であるし、本発明の要旨を逸脱しない範囲で、構成の一部を省略、変更することも可能である。 The configurations shown in the above embodiments show an example of the content of the present invention, and can be combined with other known techniques, and the configurations of the configurations are possible without departing from the gist of the present invention. It is also possible to omit or change parts.

１ 三相変圧器、２ 三相電源、３ 三相遮断器、３ａ，３ｂ，３ｃ 接触子、４ 投入位相信号、５ 主回路電流信号、６ 残留磁束算出手段、７ 残留磁束信号、８ 投入磁束誤差算出手段、１２ 投入磁束誤差信号、１３ 目標閉極位相算出手段、１４ 目標閉極位相信号、１５ 制御手段、１７ 電圧測定器、１８ 電源電圧信号、１９ａ 開極指令、１９ｂ 閉極指令、２０ａ 開極制御信号、２０ｂ 閉極制御信号、２１，２１ａ，２１ｂ，２１ｃ 計器用変流器、２２ 目標開極位相設定手段、２３ 開極位相信号、２４ 目標開極位相信号、４０ 励磁突入電流抑制装置、５０，５１ 電力開閉装置。 1 three-phase transformer, 2 three-phase power supply, 3 three-phase circuit breaker, 3a, 3b, 3c contactor, 4 closing phase signal, 5 main circuit current signal, 6 residual flux calculation means, 7 residual flux signal, 8 closing flux Error calculating means, 12 applied magnetic flux error signal, 13 target closing phase calculating means, 14 target closing phase signal, 15 controlling means, 17 voltage measuring device, 18 power supply voltage signal, 19a opening command, 19b closing command, 20a Opening control signal, 20b Closing control signal, 21, 21a, 21b, 21c Current transformer for instrument, 22 Target opening phase setting means, 23 Opening phase signal, 24 Target opening phase signal, 40 Excitation inrush current suppression Equipment, 50,51 Power switchgear.

Claims (6)

三相変圧器への三相電源の投入後に発生する励磁突入電流に基づいて、前記三相電源の開極時の前記三相変圧器の鉄心に残留する磁束である残留磁束を算出する残留磁束算出手段と、
前記三相電源の位相の変化によって生じる定常磁束と前記残留磁束との差分である投入磁束誤差を算出する誤差算出手段と、
前記投入磁束誤差に基づいて前記三相変圧器に前記三相電源を投入する位相である目標閉極位相を決定する目標閉極位相算出手段と、
前記目標閉極位相で前記三相変圧器に前記三相電源を投入させる制御手段と、を備え、
前記残留磁束算出手段は、前記励磁突入電流が発生した発生時間と前記三相電源が投入された投入時間に基づいて前記残留磁束を算出することを特徴とする励磁突入電流抑制装置。 Residual magnetic flux for calculating the residual magnetic flux, which is the magnetic flux remaining in the iron core of the three-phase transformer when the three-phase power source is opened, based on the magnetizing inrush current generated after the three-phase power source is turned on. Calculation means,
An error calculating unit that calculates a closing magnetic flux error that is a difference between the steady magnetic flux generated by the change in the phase of the three-phase power source and the residual magnetic flux,
Target closing phase calculating means for determining a target closing phase which is a phase for applying the three-phase power to the three-phase transformer based on the input magnetic flux error,
Control means for causing the three-phase transformer to turn on the three-phase power at the target closed-pole phase ,
The residual magnetic flux calculation means, the transformer inrush current suppression apparatus wherein the three-phase power supply and generating time magnetizing inrush current is generated is characterized that you calculate the residual magnetic flux based on the entered on time. 前記残留磁束算出手段は、前記残留磁束をΔφとし、前記三相変圧器の鉄心の飽和磁束閾値をφ０とし、前記投入時間をｔ０とし、前記発生時間をｔ１とした場合に、
Δφ＝φ０ − ｓｉｎ（ωｔ１）＋ｓｉｎ（ωｔ０）
の関係から前記残留磁束を算出することを特徴とする請求項１に記載の励磁突入電流抑制装置。 The residual magnetic flux calculating means sets the residual magnetic flux to Δφ, the saturation magnetic flux threshold of the iron core of the three-phase transformer to φ 0 , the closing time to t 0 , and the generation time to t 1 ,
Δφ=φ 0 −sin(ωt 1 )+sin(ωt 0 )
The magnetizing inrush current suppressing device according to claim 1 , wherein the residual magnetic flux is calculated from the relationship 三相変圧器への三相電源の投入後に発生する励磁突入電流に基づいて、前記三相電源の開極時の前記三相変圧器の鉄心に残留する磁束である残留磁束を算出する残留磁束算出手段と、
前記三相電源の位相の変化によって生じる定常磁束と前記残留磁束との差分である投入磁束誤差を算出する誤差算出手段と、
前記投入磁束誤差に基づいて前記三相変圧器に前記三相電源を投入する位相である目標閉極位相を決定する目標閉極位相算出手段と、
前記目標閉極位相で前記三相変圧器に前記三相電源を投入させる制御手段と、を備え、 前記残留磁束算出手段は、前記励磁突入電流の継続時間に基づいて前記残留磁束を算出することを特徴とする励磁突入電流抑制装置。 Residual magnetic flux for calculating the residual magnetic flux, which is the magnetic flux remaining in the iron core of the three-phase transformer when the three-phase power source is opened, based on the inrush current generated after the three-phase power source is turned on. Calculation means,
An error calculating means for calculating a closing magnetic flux error which is a difference between the steady magnetic flux generated by the change in the phase of the three-phase power source and the residual magnetic flux,
Target closing phase calculating means for determining a target closing phase which is a phase for applying the three-phase power to the three-phase transformer based on the input magnetic flux error,
Control means for causing the three-phase transformer to turn on the three-phase power at the target closed-pole phase, the residual magnetic flux calculating means calculating the residual magnetic flux based on the duration of the excitation inrush current. excitation磁突input current suppressing device characterized. 前記三相電源の開極時の位相である開極位相と前記残留磁束との関係に基づいて前記残留磁束と開極時間ばらつきによって実際の開極時に生じうる残留磁束との差である残留磁束誤差を算出し、前記残留磁束誤差に基づいて目標開極位相を設定する目標閉極位相設定手段をさらに備えることを特徴とする請求項１から請求項３のいずれか１つに記載の励磁突入電流抑制装置。 The residual magnetic flux, which is the difference between the residual magnetic flux and the residual magnetic flux that may occur during actual opening due to the variation in the opening time, based on the relationship between the open magnetic phase, which is the phase when the three-phase power source is open, and the residual magnetic flux. The excitation rush according to any one of claims 1 to 3 , further comprising target closing phase setting means for calculating an error and setting a target opening phase based on the residual magnetic flux error. Current suppression device. 前記目標閉極位相算出手段は、初期投入時は残留磁束が０であるとして目標閉極位相を決定することを特徴とする請求項１から請求項４のいずれか１つに記載の励磁突入電流抑制装置。 The magnetizing inrush current according to any one of claims 1 to 4 , wherein the target closed-pole phase calculating means determines the target closed-pole phase on the assumption that the residual magnetic flux is 0 at the initial closing. Suppressor. 三相電源が投入される三相変圧器と、
前記三相変圧器への前記三相電源の投入および遮断を行う三相遮断器と、
前記三相変圧器への電流を計測する電流計測器と、
請求項１から請求項５のいずれか１つに記載の励磁突入電流抑制装置と、を備えることを特徴とする電力開閉装置。 A three-phase transformer to which the three-phase power is turned on,
A three-phase circuit breaker for turning on and off the three-phase power source to the three-phase transformer,
A current measuring device for measuring the current to the three-phase transformer,
A magnetism inrush current suppressing device according to any one of claims 1 to 5 , and a power switchgear.
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