JP2007295747A - Serial instantaneous voltage drop compensator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform high-speed instantaneous drop compensation while suppressing the exciting rush current and the bias magnetism of a transformer in a serial instantaneous voltage drop compensator. <P>SOLUTION: A controller 7 switches its phase control into any of early input phase control which starts the input of compensating voltage after π/2-(θd1+θd2)[rad] since detection of instantaneous voltage drop, input phase control which waits for it until π/2[rad] or 3π/2[rad], and instantaneous input phase control which starts it immediately, including the delay time θd1 from the occurrence of instantaneous voltage to detection and the delay time θd2 from the desired time to completion of compensation. The early input phase control or the instantaneous input phase control includes raising/lowering the reference compensating voltage V<SB>b</SB>by the amount Vc' of compensation during one cycle. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

本発明は、交流電源の瞬時電圧低下（瞬低）を補償する直列型瞬時電圧低下補償装置に係り、特に電力変換器による補償電圧の投入位相制御に関する。   The present invention relates to a series type instantaneous voltage drop compensator that compensates for an instantaneous voltage drop (instantaneous drop) of an AC power supply, and more particularly, to a compensation voltage input phase control by a power converter.

直列型瞬時電圧低下補償装置は、図１０に破線ブロックで基本構成を示すように、商用の交流電源１と負荷２の間に、変圧器３の二次巻線を直列に介挿し、変圧器３の一次巻線には電力変換器としての可変電圧型インバータ４の出力を補償電圧として印加できる構成にされる。インバータ４は、蓄電池や電気二重層キャパシタなどの蓄電体５を直流電源とし、交流電源１とはその検出電圧を基に周波数と位相を同期させた待機状態にしておき、交流電源１に電圧低下が発生したときにその補償電圧を変圧器３の一次巻線に投入させ、負荷２に対する電源電圧の低下を抑制する。この装置において、短絡スイッチ６を設けておき、電圧補償時にそれまでの投入状態から開放制御するものもある。   The series type instantaneous voltage drop compensator includes a secondary winding of a transformer 3 inserted in series between a commercial AC power source 1 and a load 2 as shown in FIG. 3 is configured such that the output of the variable voltage inverter 4 serving as a power converter can be applied as a compensation voltage to the primary winding. The inverter 4 uses a power storage unit 5 such as a storage battery or an electric double layer capacitor as a DC power supply, and the AC power supply 1 is in a standby state in which the frequency and phase are synchronized based on the detected voltage, and the voltage drops to the AC power supply 1. When this occurs, the compensation voltage is applied to the primary winding of the transformer 3 to suppress a decrease in the power supply voltage with respect to the load 2. In this device, there is also a device in which a short-circuit switch 6 is provided and the opening control is performed from the current on state at the time of voltage compensation.

ここで、インバータ４から変圧器３に補償電圧を印加すると、変圧器３には大きな励磁突入電流が流れる。この突入電流を抑制するため、インバータ４の出力電圧指令を０から徐々に補償電圧まで高めるのでは、その遅れ（数秒）で電圧補償ができない。   Here, when a compensation voltage is applied from the inverter 4 to the transformer 3, a large magnetizing inrush current flows through the transformer 3. In order to suppress this inrush current, if the output voltage command of the inverter 4 is gradually increased from 0 to the compensation voltage, voltage compensation cannot be performed with a delay (several seconds).

この課題を解決するため、交流電源電圧の９０゜（π／２［ｒａｄ］）若しくは２７０゜（３π／２［ｒａｄ］）のタイミングでインバータから変圧器に補償電圧を印加することで、迅速な補償を実現しつつ変圧器の励磁突入電流を抑制する手法を本願出願人は既に提案している（例えば、特許文献１参照）。   In order to solve this problem, the compensation voltage is applied from the inverter to the transformer at the timing of 90 ° (π / 2 [rad]) or 270 ° (3π / 2 [rad]) of the AC power supply voltage. The present applicant has already proposed a method for suppressing the magnetizing inrush current of the transformer while realizing the compensation (see, for example, Patent Document 1).

この手法を原理的に説明すると、変圧器の磁束をφ、初期磁束をφ₀、巻数をＮとし、その巻線の印加電圧Ｕ（ｔ）の間には式（Ａ）が成り立つ。 The principle of this method will be described. The transformer magnetic flux is φ, the initial magnetic flux is φ ₀ , the number of turns is N, and the equation (A) is established between the applied voltages U (t) of the windings.

初期磁束がφ₀＝０である時に、磁束は式（Ｂ）となる。 When the initial magnetic flux is φ ₀ = 0, the magnetic flux is expressed by equation (B).

（Ｂ）式より、補償電圧を発生させる位相を電源電圧波形の９０゜（π／２［ｒａｄ］）若しくは２７０゜（３π／２［ｒａｄ］）にすれば、変圧器の励磁突入電流を抑制できる。つまり、φ₀＝９０゜または２７０゜の時にはｃｏｓθ₀＝０で、｜φ（ｘ）｜＝Ｖｍ・ｃｏｓｘ／Ｎが成り立ち、鉄心磁束は、正方向の最大磁束と負方向の最大磁束とが等しくなるため、鉄心に磁束の飽和が発生しなくなり、励磁突入電流を抑制できる。 If the phase for generating the compensation voltage is set to 90 ° (π / 2 [rad]) or 270 ° (3π / 2 [rad]) of the power supply voltage waveform, the inrush current of the transformer is suppressed. it can. That is, when φ ₀ = 90 ° or 270 °, cos θ ₀ = 0, and | φ (x) | = Vm · cosx / N holds, and the iron core magnetic flux has the maximum positive magnetic flux and the maximum negative magnetic flux. Since they are equal, magnetic flux saturation does not occur in the iron core, and the magnetizing inrush current can be suppressed.

この手法は、励磁突入電流の抑制に加えて、磁束飽和が発生しないため、変圧器の直流偏磁の抑制もできる。この直流偏磁の他の抑制方法としては、変圧器の一次側または二次側の検出電流から変圧器の励磁電流が最大になる位相を求め、この最大位相を中心とした一定期間のみ検出電流を積分することで変圧器に流れる直流成分を求め、これを電力変換器の電圧指令補正値とするものがある（例えば、特許文献２参照）。
特開２００２−０９５２６５号公報 特許第３４６３１６４号公報 In addition to the suppression of the magnetizing inrush current, this method can also suppress the DC bias of the transformer because magnetic flux saturation does not occur. Another method of suppressing this DC bias is to determine the phase at which the transformer excitation current is maximized from the detected current on the primary or secondary side of the transformer, and to detect the current only for a certain period centered on this maximum phase. Is obtained as a voltage command correction value for the power converter (see, for example, Patent Document 2).
JP 2002-095265 A Japanese Patent No. 3463164

直列変圧器を用いて電圧補償を行う場合、電力変換器から補償電圧を投入する際の電圧位相によっては直列変圧器に生じる磁束が大きくなり（直流偏磁）、変圧器の大型化につながるという問題がある。そこで、補償電圧を投入する際の各相の電圧位相を制御（投入位相制御）し、変圧器に生じる磁束を抑制することで変圧器の小型化が期待できる。   When voltage compensation is performed using a series transformer, depending on the voltage phase when the compensation voltage is supplied from the power converter, the magnetic flux generated in the series transformer increases (DC bias), which leads to an increase in the size of the transformer. There's a problem. Therefore, it is possible to reduce the size of the transformer by controlling the voltage phase of each phase (injection phase control) when applying the compensation voltage and suppressing the magnetic flux generated in the transformer.

前記の特許文献１（特開２００２−０９５２６５）に記載されるように、補償電圧をπ／２［ｒａｄ］または３π／２［ｒａｄ］で投入することで直列変圧器に生じる磁束は直流バイアス分を含まない正弦波状の波形になり、最大磁束を最も抑制でき、直列変圧器の小型化が期待できる。   As described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2002-095265), the magnetic flux generated in the series transformer by applying the compensation voltage at π / 2 [rad] or 3π / 2 [rad] is the DC bias component. The maximum magnetic flux can be suppressed most, and the series transformer can be miniaturized.

しかし、瞬時電圧低下補償装置において、瞬低発生位相に関わらずπ／２［ｒａｄ］または３π／２［ｒａｄ］から補償電圧を投入する励磁突入電流抑制では、瞬低発生時の位相がπ／２［ｒａｄ］または３π／２［ｒａｄ］に達するまで待って補償電圧を印加することになり、所望の時間内に電圧回復ができないという問題がある。   However, in the instantaneous voltage drop compensator, in the excitation inrush current suppression in which the compensation voltage is applied from π / 2 [rad] or 3π / 2 [rad] regardless of the sag occurrence phase, the phase at the time of sag occurrence is π / The compensation voltage is applied after 2 [rad] or 3 [pi] / 2 [rad] is reached, and there is a problem that the voltage cannot be recovered within a desired time.

同様に、前記の特許文献２（特許第３４６３１６４号公報）に記載されるように、検出電流を積分する期間として交流電圧のゼロクロス点もしくはゼロクロス点から＋π／６［ｒａｄ］もしくは−π／６［ｒａｄ］だけ移相した時点とした偏磁抑制では、瞬低発生時に所望の時間内に電圧回復ができないという問題がある。   Similarly, as described in the above-mentioned Patent Document 2 (Japanese Patent No. 3463164), the period for integrating the detection current is + π / 6 [rad] or −π / 6 [from the zero cross point or zero cross point of the AC voltage. rad] has a problem in that the voltage cannot be recovered within a desired time when an instantaneous drop occurs.

本発明の目的は、変圧器の励磁突入電流および偏磁を抑制しながら、高速の瞬低補償ができる直列型瞬時電圧低下補償装置を提供することにある。   An object of the present invention is to provide a series type instantaneous voltage drop compensator capable of high-speed instantaneous voltage drop compensation while suppressing the magnetizing inrush current and the magnetic bias of the transformer.

本発明は、前記の課題を解決するため、瞬低を検出した時点での系統電圧の位相によって、補償電圧を投入するタイミングを早め投入位相制御、π／２［ｒａｄ］（９０°）投入位相制御、瞬時投入位相制御に切り替えるようにし、さらに補償電圧を１周期の間は基準補償電圧Ｖ_bを補正分Ｖｃ’だけ低めまたは高めたもので、以下の構成を特徴とする。 In order to solve the above-mentioned problem, the present invention advances the timing at which the compensation voltage is input according to the phase of the system voltage at the time when the instantaneous voltage drop is detected, and provides a phase control with a phase of π / 2 [rad] (90 °). control, to switch instantaneously closing phase control, further between the compensation voltage for one period in which the reference compensation voltage V _b was only reduced or elevated correction amount Vc ', characterized by the following arrangement.

（１）交流電源と負荷の間に変圧器を直列に介挿し、交流電源の瞬時電圧低下時に電力変換器の出力を前記変圧器に補償電圧として投入させる直列型瞬時電圧低下補償装置において、
前記電力変換器の制御装置は、
瞬時電圧低下の発生から検出までの遅れ時間をθｄ１［ｒａｄ］、所望の時間から補償完了までの遅れ時間をθｄ２［ｒａｄ］とすると、
瞬時電圧低下を検出した時点での交流電源電圧の位相θ_dが０〜（θｄ１＋θｄ２）［ｒａｄ］、またはπ〜π＋（θｄ１＋θｄ２）［ｒａｄ］のときは瞬時電圧低下検出からπ／２−（θｄ１＋θｄ２）［ｒａｄ］後に前記補償電圧の投入を開始する早め投入位相制御、
瞬時電圧低下を検出した時点での交流電源電圧の位相θ_dが（θｄ１＋θｄ２）〜π／２［ｒａｄ］、またはπ＋（θｄ１＋θｄ２）〜３π／２［ｒａｄ］のときはπ／２［ｒａｄ］または３π／２［ｒａｄ］まで待ってから前記補償電圧の投入を開始するπ／２［ｒａｄ］、３π／２［ｒａｄ］投入位相制御、
瞬時電圧低下を検出した時点での交流電源電圧の位相θ_dがπ／２〜π［ｒａｄ］または３π／２〜２π［ｒａｄ］のときは直ちに前記補償電圧の投入を開始する瞬時投入位相制御、
のいずれかに切り替える手段を備えたことを特徴とする。 (1) In a series type instantaneous voltage drop compensator that inserts a transformer in series between an AC power supply and a load, and causes the output of the power converter to be input to the transformer as a compensation voltage when the instantaneous voltage drops of the AC power supply.
The power converter control device comprises:
If the delay time from occurrence of instantaneous voltage drop to detection is θd1 [rad], and the delay time from desired time to completion of compensation is θd2 [rad],
When the phase θ _d of the AC power supply voltage at the time when the instantaneous voltage drop is detected is 0 to (θd1 + θd2) [rad], or π to π + (θd1 + θd2) [rad], π / 2− (θd1 + θd2) is detected from the instantaneous voltage drop detection. ) Early-on phase control to start supplying the compensation voltage after [rad],
When the phase θ _d of the AC power supply voltage at the time when the instantaneous voltage drop is detected is (θd1 + θd2) to π / 2 [rad], or π + (θd1 + θd2) to 3π / 2 [rad], π / 2 [rad] or Π / 2 [rad], 3π / 2 [rad] input phase control for starting input of the compensation voltage after waiting for 3π / 2 [rad],
When the phase θ _d of the AC power supply voltage at the time when the instantaneous voltage drop is detected is π / 2 to π [rad] or 3π / 2 to 2π [rad], the instantaneous input phase control immediately starts to input the compensation voltage. ,
A means for switching to any one of the above is provided.

（２）前記早め投入位相制御は、瞬時電圧低下を検出した時点での交流電源電圧の位相θ_dが０〜（θｄ１＋θｄ２）［ｒａｄ］のときは補償電圧を基準補償電圧よりも低めに制御し、π〜π＋（θｄ１＋θｄ２）［ｒａｄ］のときは補償電圧を基準補償電圧よりも高めに制御し、早め投入による変圧器の直流偏磁を抑制することを特徴とする。 (2) The early turning-on phase control controls the compensation voltage to be lower than the reference compensation voltage when the phase θ _d of the AC power supply voltage at the time when the instantaneous voltage drop is detected is 0 to (θd1 + θd2) [rad]. , .Pi. To .pi. + (. Theta.d1 + .theta.d2) [rad], the compensation voltage is controlled to be higher than the reference compensation voltage, thereby suppressing the DC bias magnetism of the transformer due to early application.

（３）前記瞬時投入位相制御は、瞬時電圧低下を検出した時点での交流電源電圧の位相θ_dがπ／２〜π［ｒａｄ］のときは補償電圧を基準補償電圧よりも高めに制御し、３π／２〜２π［ｒａｄ］のときは補償電圧を基準補償電圧よりも低めに制御し、瞬時投入による変圧器の直流偏磁を抑制することを特徴とする。 (3) The instantaneous input phase control controls the compensation voltage to be higher than the reference compensation voltage when the phase θ _d of the AC power supply voltage at the time when the instantaneous voltage drop is detected is π / 2 to π [rad]. In the case of 3π / 2 to 2π [rad], the compensation voltage is controlled to be lower than the reference compensation voltage, thereby suppressing the DC demagnetization of the transformer due to instantaneous input.

（４）前記早め投入位相制御は、瞬時電圧低下を検出した時点での交流電源電圧の位相θ_dが０〜（θｄ１＋θｄ２）［ｒａｄ］のときの補償電圧を１周期の間は基準補償電圧Ｖ_bを補正分Ｖ_c’だけ低め、π〜π＋（θｄ１＋θｄ２）［ｒａｄ］のときの補償電圧を１周期の間は基準補償電圧Ｖ_bを補正分Ｖ_c’だけ高め、
前記補正分Ｖ_c’は瞬時電圧低下を検出した時点での交流電源電圧の位相θ_dが０〜（θｄ１＋θｄ２）［ｒａｄ］のときδ＊θ_d／（θｄ１＋θｄ２）−δ、π〜π＋（θｄ１＋θｄ２）［ｒａｄ］のとき−δ＊（θ_d−π）／（θｄ１＋θｄ２）＋δとし、θ_d・が（θｄ１＋θｄ２）［ｒａｄ］またはπ＋（θｄ１＋θｄ２）［ｒａｄ］に近づくにつれて、θ_d＝０またはπのときのＶ_bに対するＶ_c’の割合δでＶ_c’の絶対値を一次関数的に減少させ、θ_d・＝（θｄ１＋θｄ２）［ｒａｄ］またはπ＋（θｄ１＋θｄ２）［ｒａｄ］でＶ_c’＝０とすることを特徴とする。 (4) the early closing phase control, the phase theta _d of the AC supply voltage at the time of detecting a momentary voltage drop 0~ (θd1 + θd2) during one period of the compensation voltage when the [rad] is the reference compensation voltage V the _b 'only low, π~π + (θd1 + θd2) [rad] compensation voltage for one period of the reference compensation voltage V _b correction amount V _c when the' correction amount V _c increased by,
The correction amount V _c ′ is δ * θ _d / (θd1 + θd2) −δ, π to π + (θd1 + θd2) when the phase θ _d of the AC power supply voltage at the time when the instantaneous voltage drop is detected is 0 to (θd1 + θd2) [rad]. ) [Rad], −δ * (θ _d −π) / (θd1 + θd2) + δ, and as θ _d · approaches (θd1 + θd2) [rad] or π + (θd1 + θd2) [rad], θ _d = 0 or π the absolute value of the reduced primary function to 'V _c at a ratio of [delta]' V _c for V _b when _{the, θ d · = (θd1 +} θd2) [rad] or π + (θd1 + θd2) [ rad] at V _c '= It is characterized by zero.

（５）前記瞬時投入位相制御は、瞬時電圧低下を検出した時点での交流電源電圧の位相θ_dがπ／２〜π［ｒａｄ］のときの補償電圧を１周期の間は基準補償電圧Ｖ_bを補正分Ｖ_c’だけ高め、瞬時電圧低下を検出した時点での交流電源電圧の位相θ_dが３π／２〜２π［ｒａｄ］のときの補償電圧を１周期の間は基準補償電圧Ｖ_bを補正分Ｖ_c’だけ低め、
前記補正分Ｖ_c’は−α＊ｃｏｓ（θ_d）、ただし、αは直列変圧器に生じる磁束の最大値を最小にするためのθ_dについての関数、とすることを特徴とする。 (5) In the instantaneous input phase control, the compensation voltage when the phase θ _d of the AC power supply voltage is π / 2 to π [rad] when the instantaneous voltage drop is detected is the reference compensation voltage V for one cycle. _b is increased by a correction amount V _c ′, and the compensation voltage when the phase θ _d of the AC power supply voltage is 3π / 2 to 2π [rad] when the instantaneous voltage drop is detected is the reference compensation voltage V for one cycle. _{Lower b} by the correction amount V _c '
The correction amount V _c ′ is −α * cos (θ _d ), where α is a function of θ _d for minimizing the maximum value of magnetic flux generated in the series transformer.

以上のとおり、本発明によれば、瞬低を検出した時点での系統電圧の位相によって、補償電圧を投入するタイミングを早め投入位相制御、π／２［ｒａｄ］または３π／２［ｒａｄ］（９０°／２７０°）投入位相制御、瞬時投入位相制御に切り替えるようにし、さらに補償電圧を１周期の間は基準補償電圧Ｖ_bを補正分Ｖｃ’だけ低めまたは高めるため、変圧器の励磁突入電流および偏磁を抑制しながら、高速の瞬低補償ができる。 As described above, according to the present invention, the timing at which the compensation voltage is input is advanced by the phase of the system voltage at the time when the instantaneous drop is detected, and the input phase control, π / 2 [rad] or 3π / 2 [rad] ( (90 ° / 270 °) In order to switch between making-up phase control and instantaneous making-up phase control, and further lowering or raising the reference compensation voltage _Vb by a correction amount Vc ′ during one period, the magnetizing inrush current of the transformer In addition, high-speed instantaneous voltage drop compensation can be performed while suppressing demagnetization.

電力供給面からは瞬時電圧低下に対する規定はないが、系統連系技術要件ガイドラインおよび分散型電源系統連系技術指針において、分散型電源の併解列時の電圧低下を１０％以内に抑制することが適正とされている。また、負荷機器の耐量に関しては、電気協同研究会による調査結果などから、電圧低下１５％以上の状態が１５ｍｓｅｃ以上継続すると、負荷機器に影響が出ることが分かっている。また、一般に負荷機器は定格電圧±１０％の範囲で正常に動作することから、瞬低に対する補償目標レベルは以下の通りとした。   Although there is no provision for instantaneous voltage drop from the power supply side, the voltage drop at the time of parallel connection of distributed power sources should be suppressed to within 10% in the grid interconnection technical requirement guidelines and the distributed power grid interconnection technical guidelines. Is considered appropriate. Moreover, regarding the withstand capability of the load device, it is known from the investigation results by the Electric Cooperative Research Group that if the voltage drop of 15% or more continues for 15 msec or more, the load device is affected. In general, load devices normally operate within the range of the rated voltage ± 10%, so the compensation target levels for the instantaneous drop are as follows.

「系統残存電圧３０％の瞬低に対して補償応答時間１／４サイクル以内に負荷電圧９０％以上の電圧回復」
また、１／４サイクル以内の電圧値については補償目標レベルの設定を除外した。 “Voltage recovery of 90% or more of load voltage within 1/4 cycle of compensation response time for instantaneous drop of 30% of system residual voltage”
In addition, the setting of the compensation target level was excluded for voltage values within ¼ cycle.

本実施形態の瞬低補償装置の制御装置構成を図１に示す。ここで説明に用いる記号を以下に示す。   FIG. 1 shows a control device configuration of the voltage sag compensator of this embodiment. Here, symbols used for explanation are shown below.

系統電圧：Ｖ_s
負荷電圧：Ｖ_l
目標電圧（瞬低が発生しない場合の負荷電圧）：Ｖ_ref
基準補償電圧（Ｖ_ref−Ｖ_sで表される不足電圧）：Ｖ_b
補正電圧（直流偏磁を抑制するためにＶ_bに追加する補正分）：Ｖ_c’
補償電圧（直列変圧器から出力される補償電圧、Ｖ_b＋Ｖ_c’に相当）：Ｖ_c
瞬低検出時の系統電圧位相：θ_d［ｒａｄ］
瞬時電圧低下発生から検出までの遅れ時間：θｄ１［ｒａｄ］
所望の時間から補償完了までの遅れ時間：θｄ２［ｒａｄ］
図１において、瞬低発生時の投入位相制御装置７は、同図中にコンピュータ制御による処理フローで示すように、補償電圧の投入タイミングは瞬低を検出したときの系統電圧位相によって以下のように切り替える。なお、瞬低発生から検出までの遅れ時間θｄ１として１ｍｓｅｃ（位相演算でπ／１０［ｒａｄ］を想定している。 System voltage: V _s
Load voltage: V _l
Target voltage (load voltage when no instantaneous drop occurs): V _ref
Reference compensation voltage (undervoltage expressed by V _ref −V _s ): V _b
Correction voltage (correction added to V _b to suppress DC bias): V _c ′
Compensation voltage (compensation voltage output from the series transformer, equivalent to V _b + V _c ′): V _c
Grid voltage phase at the time of instantaneous voltage drop detection: θ _d [rad]
Delay time from occurrence of instantaneous voltage drop to detection: θd1 [rad]
Delay time from desired time to completion of compensation: θd2 [rad]
In FIG. 1, as shown in the processing flow by computer control in the figure, the closing phase control device 7 at the time of occurrence of a sag is as follows according to the system voltage phase when the sag is detected. Switch to. In addition, 1 msec (π / 10 [rad] is assumed in the phase calculation) as the delay time θd1 from the occurrence of the instantaneous drop to the detection.

（ａ）早め投入位相制御
従来の投入位相制御方法のように、π／２［ｒａｄ］投入位相制御を採用すると、このときの磁束は電圧を積分することによって得られるから直流偏磁を全く含まない波形になる（後に記載する（ｂ）π／２［ｒａｄ］投入位相制御を参照）。しかし、補償電圧投入までの待機時間が長くなり、１／４サイクル以内に９０％以上の電圧回復が実現できないという問題がある。 (A) Early closing phase control When π / 2 [rad] closing phase control is adopted as in the conventional closing phase control method, the magnetic flux at this time is obtained by integrating the voltage, and thus does not include DC bias. (See (b) π / 2 [rad] input phase control described later). However, there is a problem that the standby time until the compensation voltage is turned on becomes long, and a voltage recovery of 90% or more cannot be realized within ¼ cycle.

早め投入位相制御（早め補償）を用いない場合のシミュレーション結果の一例として、ｕ相の瞬低検出時の系統電圧位相θ_dがπ／１０［ｒａｄ］（瞬低発生位相は０［ｒａｄ］）である場合のＶ_l波形を図２に示す。また、Ｖ_refとＶ_lの差を図３に示す。図３をみると、瞬低発生後から１／４サイクル以内に目標電圧との差が１０％以内にならず、つまり、９０％以上の電圧回復が実現できず、電圧が９０％以上に回復するのはπ／２０［ｒａｄ］だけ遅れてからであることがわかる。 As an example of the simulation result in the case of not using the early input phase control (early compensation), the system voltage phase θ _d at the time of detecting the u-phase voltage drop is π / 10 [rad] (the voltage drop generation phase is 0 [rad]). FIG. 2 shows the V _l waveform when. The difference between V _ref and V _l is shown in FIG. As shown in FIG. 3, the difference from the target voltage does not become less than 10% within 1/4 cycle after the occurrence of the instantaneous drop, that is, 90% or more voltage recovery cannot be realized, and the voltage recovers to 90% or more It can be seen that this is done after a delay of π / 20 [rad].

したがって、補償開始をπ／２０［ｒａｄ］だけ早めれば、つまり補償電圧を９π／２０［ｒａｄ］から投入開始すれば所望の電圧補償が実現できる。すなわち、補償開始をθｄ２［ｒａｄ］だけ早め、補償電圧を瞬時電圧低下検出からπ／２−（θｄ１＋θｄ２）後から投入開始すれば所望の電圧補償が実現できる。   Therefore, if the compensation start is advanced by π / 20 [rad], that is, if the compensation voltage is started from 9π / 20 [rad], a desired voltage compensation can be realized. That is, the desired voltage compensation can be realized if the compensation start is advanced by θd2 [rad] and the compensation voltage is turned on after π / 2− (θd1 + θd2) after the instantaneous voltage drop detection.

また、このことから、瞬低発生位相をずらしていったとき、π／２［ｒａｄ］で補償開始する場合とはθ_d＝３π／２０［ｒａｄ］（＝θｄ１＋θｄ２）で瞬低を検出する場合であることがわかる。 Further, from this, when the phase of occurrence of sag drops is shifted, the case of starting the compensation with π / 2 [rad] is different from the case of detecting sag with θ _d = 3π / 20 [rad] (= θd1 + θd2). It can be seen that it is.

したがって、早め投入位相制御には、図１に示すように、瞬低検出時の系統電圧位相θ_dが０〜（θｄ１＋θｄ２）［ｒａｄ］では瞬時電圧低下検出からπ／２−（θｄ１＋θｄ２）［ｒａｄ］後に補償を開始、または位相θ_dがπ〜π＋（θｄ１＋θｄ２）［ｒａｄ］では瞬時電圧低下検出からπ／２−（θｄ１＋θｄ２）［ｒａｄ］後に補償を開始する。 Therefore, as shown in FIG. 1, in the early closing phase control, as shown in FIG. 1, when the system voltage phase θ _d at the time of instantaneous voltage drop is 0 to (θd1 + θd2) [rad], π / 2− (θd1 + θd2) [rad ] After that, or when the phase θ _d is π to π + (θd1 + θd2) [rad], the compensation is started after π / 2− (θd1 + θd2) [rad] after detection of the instantaneous voltage drop.

上記の早め投入位相制御において、補償電圧の投入をπ／２［ｒａｄ］より早めた場合の電圧を積分すると早めた分が直流分として磁束に重畳されることになる。したがって、図４に示すように早め補償を適用する場合は、補正を減じて基準補償電圧よりも小さな補償電圧とすれば直流偏磁を緩和できる。   In the above-described early application phase control, when the voltage when the compensation voltage is applied earlier than π / 2 [rad] is integrated, the earlier part is superimposed on the magnetic flux as a direct current component. Therefore, as shown in FIG. 4, when early compensation is applied, DC bias can be mitigated by reducing the correction to a compensation voltage smaller than the reference compensation voltage.

早め補償を行わない場合、最も補償が遅れるのはθ_d＝０［ｒａｄ］のときである。このときは補償電圧を投入するまでの時間が最も長いことから、低め補償制御としてＶ_bに対して最も大きなＶ_c’を減じる必要がある。この場合のＶ_c’の大きさを基準補償電圧の１０％に設定した。Ｖ_c’はθｄが３π／２０［ｒａｄ］に近づくにつれて小さな値で済み、θ_d＝３π／２０［ｒａｄ］のときは従来のπ／２［ｒａｄ］投入位相制御と同じであるからＶ_c’＝０でよい。したがって、θ_dについてＶ_c’として単調増加する式（１）のような関数を用いた。また、Ｖ_bに補正を加えるのは補償開始後１周期としている。 When the early compensation is not performed, the compensation is most delayed when θ _d = 0 [rad]. At this time, since the time until the compensation voltage is supplied is the longest, it is necessary to reduce the largest V _c ′ with respect to V _b as the lower compensation control. In this case, the magnitude of V _c ′ was set to 10% of the reference compensation voltage. V _c 'is θd is requires only small values closer to 3π / 20 [rad], θ d = 3π / 20 [rad] V c from is the same as the conventional π / 2 [rad] closing phase control when '= 0. Therefore, a function such as the equation (1) that monotonously increases as V _c ′ for θ _d is used. Further, the correction to V _b is made one period after the start of compensation.

以上の関係をまとめると表１のようになる。   The above relationship is summarized as shown in Table 1.

したがって、早め投入位相制御には、瞬時電圧低下を検出した時点での系統電圧位相θ_dが０〜（θｄ１＋θｄ２）［ｒａｄ］のときの補償電圧を１周期の間は基準補償電圧Ｖｂを補正分Ｖ_c’だけ低め、π〜π＋（θｄ１＋θｄ２）［ｒａｄ］のときの補償電圧を１周期の間は基準補償電圧Ｖｂを補正分Ｖ_c’だけ高める。この補正分Ｖ_c’は瞬時電圧低下を検出した時点での系統電圧位相θ_dが０〜（θｄ１＋θｄ２）［ｒａｄ］のときδ＊θ_d／（θｄ１＋θｄ２）−δ、π〜π＋（θｄ１＋θｄ２）［ｒａｄ］のとき−δ＊（θ_d−π）／（θｄ１＋θｄ２）＋δとし、θ_d・が（θｄ１＋θｄ２）［ｒａｄ］またはπ＋（θｄ１＋θｄ２）［ｒａｄ］に近づくにつれてＶ_c’の絶対値は小さくてもよいため、θ_d＝０またはπのときのＶｂに対するＶ_c’の割合δでＶ_c’の絶対値を一次関数的に減少させ、θ_d＝（θｄ１＋θｄ２）［ｒａｄ］またはπ＋（θｄ１＋θｄ２）［ｒａｄ］でＶ_c’＝０とする。 Therefore, in the early closing phase control, the compensation voltage when the system voltage phase θ _d at the time when the instantaneous voltage drop is detected is 0 to (θd1 + θd2) [rad], the reference compensation voltage Vb is corrected for one period. 'only lower, π~π + (θd1 + θd2) during one period of the compensation voltage when the [rad] is a standard compensation voltage Vb correction amount V _c' V _c increasing only. This correction amount V _c ′ is δ * θ _d / (θd 1 + θd 2) −δ, π to π + (θd 1 + θd 2) when the system voltage phase θ _d when the instantaneous voltage drop is detected is 0 to (θd 1 + θd 2) [rad]. rad], −δ * (θ _d −π) / (θd1 + θd2) + δ, and the absolute value of V _c ′ decreases as θ _d · approaches (θd1 + θd2) [rad] or π + (θd1 + θd2) [rad]. for even better, θ _d = 0 or [pi Vb absolute value of reducing a linear function manner 'V _c at a ratio of [delta]' V _c for the _{time, θ d = (θd1 + θd2} ) [rad] or π + (θd1 + θd2) In [rad], V _c ′ = 0.

また、早め補償および低め補償を適用した場合に先ほどと同じ条件の下でシミュレーションによって求めたＶ_l波形を図５に示す。また、Ｖ_refとＶ_lの差を図６に示す。図６から瞬低発生後、１／４サイクル以内に９０％以上の電圧回復が実現できていることがわかる。 Also shows a V _l waveform obtained by simulation under the same conditions as before in the case of applying the early compensation and lower compensation in FIG. The difference between V _ref and V _l is shown in FIG. As can be seen from FIG. 6, voltage recovery of 90% or more can be realized within 1/4 cycle after the occurrence of the instantaneous drop.

（ｂ）π／２［ｒａｄ］（９０°）投入位相制御
上記の（ａ）における考察から、θ_dが３π／２０〜π／２［ｒａｄ］のときは補償をπ／２［ｒａｄ］から開始しても所望の電圧補償を実現することができるため、早め投入位相制御は不要となる。図７に示すように、π／２［ｒａｄ］から補償を開始することで、Ｖ_c’＝０として電圧波形を積分しても磁束波形は直流分を含まない波形となり、直流偏磁は発生しない。したがって、θ_dが（θｄ１＋θｄ２）〜π／２［ｒａｄ］、またはπ＋（θｄ１＋θｄ２）〜３π／２［ｒａｄ］のときはπ／２［ｒａｄ］または３π／２［ｒａｄ］まで待ってから前記補償電圧の投入を開始する。また、Ｖ_bに対して補正を加えず、Ｖ_c＝Ｖ_bである。 (B) π / 2 [rad] (90 °) input phase control From the consideration in the above (a), when θ _d is 3π / 20 to π / 2 [rad], compensation starts from π / 2 [rad]. Since the desired voltage compensation can be realized even if it is started, the early closing phase control is unnecessary. As shown in FIG. 7, by starting compensation from π / 2 [rad], even if the voltage waveform is integrated with V _c ′ = 0, the magnetic flux waveform does not include a DC component, and DC bias is generated. do not do. Therefore, when θ _d is (θd1 + θd2) to π / 2 [rad], or π + (θd1 + θd2) to 3π / 2 [rad], the compensation is performed after waiting for π / 2 [rad] or 3π / 2 [rad]. Start applying voltage. Also, without applying correction to V _b, it is V _c = V _b.

（ｃ）瞬時投入位相制御
θ_dがπ／２〜π［ｒａｄ］のとき、図８に示すように、瞬低検出後、直ちに補償を開始する。従来のように補償開始を３π／２［ｒａｄ］まで待ってしまうと、磁束の最大値は最も抑制できるが所望の時間内に規定の電圧回復が不可能となるためである。ただし、すぐに補償を開始することで、直流偏磁の増加の原因となる。そこで、直列変圧器に生じる直流偏磁を抑制するためにＶ_c’を加えてＶ_bを高める制御を追加する。 (C) Instantaneous closing phase control When θ _d is π / 2 to π [rad], as shown in FIG. This is because when the compensation start is waited until 3π / 2 [rad] as in the prior art, the maximum value of the magnetic flux can be suppressed most, but the specified voltage recovery becomes impossible within a desired time. However, starting compensation immediately causes an increase in DC bias. Therefore, control for increasing V _b by adding V _c ′ is added in order to suppress direct-current bias generated in the series transformer.

直流偏磁を抑制するため、Ｖ_c’はθ_dがπ／２からπ［ｒａｄ］に近づくにつれて大きな値である必要がある。このような要求を満たすＶ_c’の関数としてθ_dについて単調増加する式（２）のような余弦関数が考えられる。Ｖ_bに対してこの補正を加えるのは瞬低補償開始後１周期の間としている。 In order to suppress DC bias, V _c ′ needs to increase as θ _d approaches from π / 2 to π [rad]. As a function of V _c ′ that satisfies such a requirement, a cosine function such as Expression (2) that monotonously increases with respect to θ _d can be considered. This correction is applied to _Vb for one period after the start of the sag compensation.

ここで、αはθ_dによって異なる値をとり、この値の決定手順を以下に示す。Ｖ_bに対して補正を加えるのは瞬低発生後の１周期であるため、直列変圧器の出力Ｖ_cは式（３）のように表される。 Here, α takes a different value depending on θ _d , and the procedure for determining this value is shown below. Since the correction to V _b is performed in one cycle after the occurrence of a sag, the output V _c of the series transformer is expressed as in Equation (3).

この電圧を積分することで、磁束φ（ｔ）は式（４）のように表される。ただし、Ｃ₁とＣ₂は積分定数である。 By integrating this voltage, the magnetic flux φ (t) is expressed as in equation (4). However, C ₁ and C ₂ is a constant of integration.

時間ｔ＝０にて磁束は０であるから、φ（０）＝０とおくことで式（５）が得られる。   Since the magnetic flux is 0 at time t = 0, formula (5) is obtained by setting φ (0) = 0.

また、ｔ＝Ｔで磁束の連続性を考えると式（６）が得られる。   Further, when considering the continuity of magnetic flux at t = T, Expression (6) is obtained.

したがって、直列変圧器に生じる磁束φ（ｔ）は式（７）のように表される。   Therefore, the magnetic flux φ (t) generated in the series transformer is expressed as in Expression (7).

以上の電圧及び磁束を図示すると図８のようになる。   The above voltage and magnetic flux are illustrated in FIG.

図８において、磁束の最大値については以下の２通りが考えられる。   In FIG. 8, the following two types are considered as the maximum value of the magnetic flux.

・αが小さい場合は電圧の補正が不足するためにｔ＝ｔ₂で磁束の最大値｜φ（ｔ₂）｜をとる。 When α is small, voltage correction is insufficient, so the maximum value of magnetic flux | φ (t ₂ ) | is taken at t = t ₂ .

・αが大きい場合は電圧の補正が過剰になるためにｔ＝ｔ₃で磁束の最大値｜φ（ｔ₃）｜をとる。 When α is large, voltage correction becomes excessive, so the maximum value of magnetic flux | φ (t ₃ ) | is taken at t = t ₃ .

また、式（３）においてＶ_c（ｔ）＝０とおくことで式（８）が得られる。 Moreover, Formula (8) is obtained by setting V _c (t) = 0 in Formula (3).

このｔ₀を用いてｔ₂とｔ₃はそれぞれ式（９）と式（ｌ０）のように表すことができる。 Using this t ₀ , t ₂ and t ₃ can be expressed as in equations (9) and (10), respectively.

この値を使って｜φ（ｔ₂）｜と｜φ（ｔ₃）｜を得ることができる。αを変化させたときのθ_dに対する｜φ（ｔ₂）｜と｜φ（ｔ₃）｜が求められるが、これらの２値のうち大きいほうをφ_maxとすると、φ_maxをできるだけ小さくすることで変圧器の小型化を実現できる。 Using this value, | φ (t ₂ ) | and | φ (t ₃ ) | can be obtained. | φ (t ₂ ) | and | φ (t ₃ ) | are obtained with respect to θ _d when α is changed. If the larger of these two values is φ _max , φ _max is made as small as possible. This makes it possible to reduce the size of the transformer.

そこで、αを変化させたときのθ_dに対するφ_maxの関係をまとめると図９のようになり、この結果からφ_maxが最小値をとるためには、θ_dによって以下の３通りのαをとればよい。 Therefore, the relationship of φ _max with respect to θ _d when α is changed is summarized as shown in FIG. 9. From this result, in order for φ _max to take the minimum value, the following three types of α are determined by θ _d . Just do it.

θ_dが
π／２〜７π／１０［ｒａｄ］のときα＝０．１３
７π／１０〜９．３π／１０［ｒａｄ］のときα＝０．１４
９．３π／１０〜π［ｒａｄ］のときα＝０．１５
で磁束の最大値を最も抑制することができる。 When θ _d is π / 2 to 7π / 10 [rad], α = 0.13
When 7π / 10 to 9.3π / 10 [rad], α = 0.14
When 9.3π / 10 to π [rad], α = 0.15
Thus, the maximum value of the magnetic flux can be most suppressed.

以上のように、瞬時投入位相制御は、瞬時電圧低下を検出した時点での交流電源電圧の位相θ_dが・／２〜・［ｒａｄ］のときの補償電圧を１周期の間は基準補償電圧Ｖｂを補正分Ｖ_c’だけ高める。逆に、瞬時電圧低下を検出した時点での交流電源電圧の位相θ_dが３π／２〜２π［ｒａｄ］のときの補償電圧を１周期の間は基準補償電圧Ｖ_bを補正分Ｖ_c’だけ低める。 As described above, in the instantaneous input phase control, the compensation voltage when the phase θ _d of the AC power supply voltage at the time when the instantaneous voltage drop is detected is the reference compensation voltage for one cycle. Vb is increased by the correction amount V _c ′. Conversely, the compensation voltage when the phase θ _d of the AC power supply voltage at the time when the instantaneous voltage drop is detected is 3π / 2 to 2π [rad], and the reference compensation voltage V _b is corrected by V _c ′ for one period. Only lower.

なお、補正分Ｖ_c’は前記式（２）から、−α＊ｃｏｓ（θ_d）とする。ただし、αは直列変圧器に生じる磁束の最大値を最小にするためのθ_dについての関数である。 The correction amount V _c ′ is −α * cos (θ _d ) based on the equation (2). However, (alpha) is a function about (theta) _d for minimizing the maximum value of the magnetic flux which arises in a series transformer.

本発明の実施形態を示す瞬低補償装置の制御装置構成図。The control unit block diagram of the sag compensation apparatus which shows embodiment of this invention. Ｖｌ波形図（早め補償なし）。Vl waveform diagram (without early compensation). 目標電圧と負荷電圧の差波形図（早め補償なし）。Difference waveform diagram of target voltage and load voltage (no early compensation). 早め投入位相制御波形図。FIG. 4 is a waveform diagram of early-on phase control. 実施形態におけるＶｌ波形図（早め補償あり）。Vl waveform diagram in the embodiment (with early compensation). 実施形態における目標電圧と負荷電圧の差波形図（早め補償あり）。FIG. 6 is a difference waveform diagram of the target voltage and the load voltage in the embodiment (with early compensation). 実施形態におけるπ／２［ｒａｄ］投入位相制御の波形図。The wave form diagram of π / 2 [rad] input phase control in the embodiment. 実施形態における瞬時投入位相制御の波形図。FIG. 6 is a waveform diagram of instantaneous input phase control in the embodiment. αを変化させたときの瞬低発生位相θ_dとφ_maxの関係図。FIG. 6 is a diagram _showing the relationship between the instantaneous drop generation phase θ _d and φ _max when α is changed. 直列型瞬時電圧低下補償装置の回路構成図。The circuit block diagram of a series type instantaneous voltage drop compensation apparatus.

符号の説明Explanation of symbols

１ 交流電源
２ 負荷
３ 変圧器
４ インバータ
５ 蓄電体
1 AC power supply 2 Load 3 Transformer 4 Inverter 5 Power storage unit

Claims (5)

交流電源と負荷の間に変圧器を直列に介挿し、交流電源の瞬時電圧低下時に電力変換器の出力を前記変圧器に補償電圧として投入させる直列型瞬時電圧低下補償装置において、
前記電力変換器の制御装置は、
瞬時電圧低下の発生から検出までの遅れ時間をθｄ１［ｒａｄ］、所望の時間から補償完了までの遅れ時間をθｄ２［ｒａｄ］とすると、
瞬時電圧低下を検出した時点での交流電源電圧の位相θ_dが０〜（θｄ１＋θｄ２）［ｒａｄ］、またはπ〜π＋（θｄ１＋θｄ２）［ｒａｄ］のときは瞬時電圧低下検出からπ／２−（θｄ１＋θｄ２）［ｒａｄ］後に前記補償電圧の投入を開始する早め投入位相制御、
瞬時電圧低下を検出した時点での交流電源電圧の位相θ_dが（θｄ１＋θｄ２）〜π／２［ｒａｄ］、またはπ＋（θｄ１＋θｄ２）〜３π／２［ｒａｄ］のときはπ／２［ｒａｄ］または３π／２［ｒａｄ］まで待ってから前記補償電圧の投入を開始するπ／２［ｒａｄ］、３π／２［ｒａｄ］投入位相制御、
瞬時電圧低下を検出した時点での交流電源電圧の位相θ_dがπ／２〜π［ｒａｄ］または３π／２〜２π［ｒａｄ］のときは直ちに前記補償電圧の投入を開始する瞬時投入位相制御、
のいずれかに切り替える手段を備えたことを特徴とする直列型瞬時電圧低下補償装置。 In a series type instantaneous voltage drop compensator that inserts a transformer in series between an AC power supply and a load, and causes the output of the power converter to be input as a compensation voltage to the transformer when the instantaneous voltage drops of the AC power supply.
The power converter control device comprises:
If the delay time from occurrence of instantaneous voltage drop to detection is θd1 [rad], and the delay time from desired time to completion of compensation is θd2 [rad],
When the phase θ _d of the AC power supply voltage at the time when the instantaneous voltage drop is detected is 0 to (θd1 + θd2) [rad], or π to π + (θd1 + θd2) [rad], π / 2− (θd1 + θd2) is detected from the instantaneous voltage drop detection. ) Early-on phase control to start supplying the compensation voltage after [rad],
When the phase θ _d of the AC power supply voltage at the time when the instantaneous voltage drop is detected is (θd1 + θd2) to π / 2 [rad], or π + (θd1 + θd2) to 3π / 2 [rad], π / 2 [rad] or Π / 2 [rad], 3π / 2 [rad] input phase control for starting input of the compensation voltage after waiting for 3π / 2 [rad],
When the phase θ _d of the AC power supply voltage at the time when the instantaneous voltage drop is detected is π / 2 to π [rad] or 3π / 2 to 2π [rad], the instantaneous input phase control immediately starts to input the compensation voltage. ,
A series type instantaneous voltage drop compensation device comprising means for switching to any one of the above. 前記早め投入位相制御は、瞬時電圧低下を検出した時点での交流電源電圧の位相θ_dが０〜（θｄ１＋θｄ２）［ｒａｄ］のときは補償電圧を基準補償電圧よりも低めに制御し、π〜π＋（θｄ１＋θｄ２）［ｒａｄ］のときは補償電圧を基準補償電圧よりも高めに制御し、早め投入による変圧器の直流偏磁を抑制することを特徴とする請求項１に記載の直列型瞬時電圧低下補償装置。 When the phase of the AC power supply voltage θ _d when the instantaneous voltage drop is detected is 0 to (θd1 + θd2) [rad], the early input phase control controls the compensation voltage to be lower than the reference compensation voltage, and π˜ 2. The series instantaneous voltage according to claim 1, wherein when π + (θd 1 + θd 2) [rad], the compensation voltage is controlled to be higher than the reference compensation voltage, and DC bias magnetism of the transformer due to early application is suppressed. Drop compensation device. 前記瞬時投入位相制御は、瞬時電圧低下を検出した時点での交流電源電圧の位相θ_dがπ／２〜π［ｒａｄ］のときは補償電圧を基準補償電圧よりも高めに制御し、３π／２〜２π［ｒａｄ］のときは補償電圧を基準補償電圧よりも低めに制御し、瞬時投入による変圧器の直流偏磁を抑制することを特徴とする請求項１に記載の直列型瞬時電圧低下補償装置。 The instantaneous input phase control controls the compensation voltage to be higher than the reference compensation voltage when the phase θ _d of the AC power supply voltage at the time when the instantaneous voltage drop is detected is π / 2 to π [rad]. 2. The series instantaneous voltage drop according to claim 1, wherein when 2 to 2π [rad], the compensation voltage is controlled to be lower than the reference compensation voltage to suppress direct current bias of the transformer due to instantaneous input. Compensation device. 前記早め投入位相制御は、瞬時電圧低下を検出した時点での交流電源電圧の位相θ_dが０〜（θｄ１＋θｄ２）［ｒａｄ］のときの補償電圧を１周期の間は基準補償電圧Ｖ_bを補正分Ｖ_c’だけ低め、π〜π＋（θｄ１＋θｄ２）［ｒａｄ］のときの補償電圧を１周期の間は基準補償電圧Ｖ_bを補正分Ｖ_c’だけ高め、
前記補正分Ｖ_c’は瞬時電圧低下を検出した時点での交流電源電圧の位相θ_dが０〜（θｄ１＋θｄ２）［ｒａｄ］のときδ＊θ_d／（θｄ１＋θｄ２）−δ、π〜π＋（θｄ１＋θｄ２）［ｒａｄ］のとき−δ＊（θ_d−π）／（θｄ１＋θｄ２）＋δとし、θ_d・が（θｄ１＋θｄ２）［ｒａｄ］またはπ＋（θｄ１＋θｄ２）［ｒａｄ］に近づくにつれて、θ_d＝０またはπのときのＶ_bに対するＶ_c’の割合δでＶ_c’の絶対値を一次関数的に減少させ、θ_d・＝（θｄ１＋θｄ２）［ｒａｄ］またはπ＋（θｄ１＋θｄ２）［ｒａｄ］でＶ_c’＝０とすることを特徴とする請求項１または２に記載の直列型瞬時電圧低下補償装置。 The early closing phase control, the phase theta _d of the AC supply voltage at the time of detecting a momentary voltage drop 0~ (θd1 + θd2) during one period of the compensation voltage when the [rad] is corrected reference compensation voltage V _b 'only lower, π~π + (θd1 + θd2) [rad] compensation voltage for one period of the reference compensation voltage V _b correction amount V _c when the' min V _c increased by,
The correction amount V _c ′ is δ * θ _d / (θd1 + θd2) −δ, π to π + (θd1 + θd2) when the phase θ _d of the AC power supply voltage at the time when the instantaneous voltage drop is detected is 0 to (θd1 + θd2) [rad]. ) [Rad], −δ * (θ _d −π) / (θd1 + θd2) + δ, and as θ _d · approaches (θd1 + θd2) [rad] or π + (θd1 + θd2) [rad], θ _d = 0 or π the absolute value of the reduced primary function to 'V _c at a ratio of [delta]' V _c for V _b when _{the, θ d · = (θd1 +} θd2) [rad] or π + (θd1 + θd2) [ rad] at V _c '= 3. The series instantaneous voltage drop compensator according to claim 1 or 2, wherein 0 is set. 前記瞬時投入位相制御は、瞬時電圧低下を検出した時点での交流電源電圧の位相θ_dがπ／２〜π［ｒａｄ］のときの補償電圧を１周期の間は基準補償電圧Ｖ_bを補正分Ｖ_c’だけ高め、瞬時電圧低下を検出した時点での交流電源電圧の位相θ_dが３π／２〜２π［ｒａｄ］のときの補償電圧を１周期の間は基準補償電圧Ｖ_bを補正分Ｖ_c’だけ低め、
前記補正分Ｖ_c’は−α＊ｃｏｓ（θ_d）、ただし、αは直列変圧器に生じる磁束の最大値を最小にするためのθ_dについての関数、とすることを特徴とする請求項１または３に記載の直列型瞬時電圧低下補償装置。
The instantaneous closing phase control, during one period of the compensation voltage when the phase theta _d of the AC supply voltage at the time of detecting a momentary voltage drop is π / 2~π [rad] is corrected reference compensation voltage V _b increased by an amount V _c ', during one period of the compensation voltage when the phase theta _d of the AC supply voltage at the time of detecting a momentary voltage drop is 3π / 2~2π [rad] is corrected reference compensation voltage V _b It lowered by an amount V _c ',
The correction amount V _c ′ is −α * cos (θ _d ), where α is a function of θ _d for minimizing the maximum value of magnetic flux generated in the series transformer. 4. The series type instantaneous voltage drop compensation device according to 1 or 3.

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