JP6783826B2 - Self-excited reactive power compensator - Google Patents

Self-excited reactive power compensator Download PDF

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JP6783826B2
JP6783826B2 JP2018131252A JP2018131252A JP6783826B2 JP 6783826 B2 JP6783826 B2 JP 6783826B2 JP 2018131252 A JP2018131252 A JP 2018131252A JP 2018131252 A JP2018131252 A JP 2018131252A JP 6783826 B2 JP6783826 B2 JP 6783826B2
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晃 神部
晃 神部
祐 桑原
祐 桑原
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Aichi Electric Co Ltd
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    • YGENERAL 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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    • Y02E40/30Reactive power compensation

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Description

本発明は、自励式無効電力補償装置を構成する補償器の定数を自動で最適値に変更する技術に関する。 The present invention relates to a technique for automatically changing a constant of a compensator constituting a self-excited reactive power compensator to an optimum value.

太陽光発電や風力発電など自然エネルギーを利用する分散型電源が配電系統に大量導入された場合、系統電圧の変動が増大することが懸念される。特に、日射や風力の急変により、これらの出力は大きく変動する。 When a large number of distributed power sources that use natural energy such as solar power generation and wind power generation are introduced into the distribution system, there is a concern that fluctuations in the system voltage will increase. In particular, these outputs fluctuate significantly due to sudden changes in solar radiation and wind power.

その影響による急激な電圧変動に対しては、変圧器のタップを切換えて電圧を調整する従来の電圧調整装置では対応できず、この問題を解決する装置としてSTATCOMなどの無効電力補償装置が有効と考えられる。 The conventional voltage regulator that adjusts the voltage by switching the tap of the transformer cannot cope with the sudden voltage fluctuation due to the influence, and a reactive power compensation device such as STATCOM is effective as a device to solve this problem. Conceivable.

STATCOMはIGBT等の半導体デバイスで構成された自励式の無効電力補償装置であり、高速な無効電力出力制御によって急激な電圧変動を迅速に抑制することができる。(下記特許文献1参照)。 The STATCOM is a self-excited reactive power compensator composed of semiconductor devices such as IGBTs, and can quickly suppress sudden voltage fluctuations by high-speed reactive power output control. (See Patent Document 1 below).

愛知電機技報No.37 p30 高圧配電線用STATCOMの開発Aichi Electric Technical Report No. 37 p30 Development of STATCOM for high-voltage distribution lines

上記STATCOMの制御系を構成する補償器の定数を決めるにあたっては、事前に配電線のインピーダンスを調査し、それに合わせて手動で最適となるよう設定していた。このため、配電系統の切り換えなどで配電線のインピーダンスが大きく変化すると、その都度補償器の設定を手動で変更する必要があった。 In determining the constants of the compensators constituting the control system of the STATCOM, the impedance of the distribution line was investigated in advance, and the impedance was manually set to be optimum accordingly. Therefore, when the impedance of the distribution line changes significantly due to the switching of the distribution system or the like, it is necessary to manually change the setting of the compensator each time.

本発明は、配電線のインピーダンスを自動計測する機能を搭載し、補償器の定数を自動で最適値に変更することのできる自励式無効電力補償装置を提供する。 The present invention provides a self-excited reactive power compensator equipped with a function of automatically measuring the impedance of a distribution line and capable of automatically changing the constant of a compensator to an optimum value.

請求項1記載の発明は、各地の高圧配電線系統のインピーダンス値に対して、系統電圧制御系の周波数特性を基に補償器定数をあらかじめ計算しておき、こうして把握しておいた補償器定数を、配電線インピーダンス値の自動計測結果に基づき自動で設定することに特徴を有する。 In the invention according to claim 1 , the compensator constant is calculated in advance based on the frequency characteristics of the system voltage control system with respect to the impedance value of the high-voltage distribution line system in each place, and the compensator constant thus grasped. and characterized in that the automatically set on the basis of automatic measurement results of the distribution line impedance value.

請求項2記載の発明は、請求項1記載の自励式無効電力補償装置において、自励式無効電力補償装置から次数間高調波の微小電流を配電系統に注入して、系統電圧の同次数の高調波を計測することで、下記式(1)で次数間高調波電流を求め、下記式(2)で次数間高調波電圧を求め、これらを入力として下記式(3)で前記配電線インピーダンスを求め、これを平均化することにより、平均化した値を前記配電線インピーダンス値と自動推定することに特徴を有する:
式(1)
式(2)
式(3)
配電線のインピーダンスZl
Zl = R + jX, R:配電線インピーダンスの抵抗分,X:配電線インピーダンスのリアクタンス分
The invention according to claim 2 is the self-excited ineffective power compensator according to claim 1, in which a minute current of interorder harmonics is injected into the distribution system from the self-excited inactive power compensator to harmonic the system voltage of the same order. By measuring the wave, the inter-order harmonic current is obtained by the following formula (1), the inter-order harmonic voltage is obtained by the following formula (2), and the distribution line impedance is calculated by the following formula (3) using these as inputs. It is characterized in that the averaged value is automatically estimated as the distribution line impedance value by obtaining and averaging this :
Equation (1)
Equation (2)
Equation (3)
Distribution line impedance Zl
Zl = R + jX, R: Resistance of distribution line impedance, X: Reactance of distribution line impedance

請求項1記載の発明によれば、配電線のインピーダンスが大きく変化した場合でも、補償器の設定を手動でする必要はない。また、補償器の最適値を系統電圧制御系の周波数特性から決定するので、制御系を安定かつ応答速度が速く、制御精度の良いものにできる。 According to the invention of claim 1, even if the impedance of the distribution line changes significantly, it is not necessary to manually set the compensator. Further, since the optimum value of the compensator is determined from the frequency characteristics of the system voltage control system, the control system can be stable, the response speed is fast, and the control accuracy is good.

請求項2記載の発明によれば、配電線インピーダンスを計測する際に、配電線に存在しない次数間高調波を用いるので、他からの影響を受けにくく、式(1)と式(2)で積分・時間平均して(ディジタルフーリエ変換を用いて)次数間高調波の電圧・電流を検出し、さらに式(3)で求めた値の平均値を採用するので、配電線のインピーダンスを精度良く推定できる。 According to the invention of claim 2, since the interorder harmonics that do not exist in the distribution line are used when measuring the distribution line impedance, it is not easily affected by others, and the equations (1) and (2) are used. The voltage and current of the interorder harmonics are detected by integration and time averaging (using digital Fourier transform), and the average value of the values obtained by Eq. (3) is adopted, so the impedance of the distribution line is accurately adjusted. Can be estimated.

本発明に係る自励式無効電力補償装置の制御ブロック図である。It is a control block diagram of the self-excited reactive power compensating device which concerns on this invention.

以下、本発明の実施の形態を図1により説明する。図1において、1は高圧配電系統に接続される自励式無効電力補償装置であり、2は補償器として機能する系統電圧制御部である。 Hereinafter, embodiments of the present invention will be described with reference to FIG. In FIG. 1, 1 is a self-excited reactive power compensator connected to a high-voltage distribution system, and 2 is a system voltage control unit that functions as a compensator.

3は逆γδ変換・逆αβ変換部であり、4は電流出力部(出力電流制御やPWM制御インバータ、LCフィルタ、昇圧変圧器を含む)、5は次数間高調波電流検出部である。 Reference numeral 3 denotes an inverse γδ conversion / inverse αβ conversion unit, 4 is a current output unit (including an output current control, a PWM control inverter, an LC filter, and a step-up transformer), and 5 is an interorder harmonic current detection unit.

6は次数間高調波電圧検出部であり、7は配電線インピーダンス演算部である。8は補償器定数決定部であり、9は次数間高調波電流指令値生成部である。10は系統電圧検出部であり、11はPLL、12は次数間高調波信号生成部である。 Reference numeral 6 denotes an inter-degree harmonic voltage detection unit, and 7 is a distribution line impedance calculation unit. Reference numeral 8 denotes a compensator constant determination unit, and 9 is an inter-degree harmonic current command value generation unit. Reference numeral 10 is a system voltage detection unit, 11 is a PLL, and 12 is an inter-degree harmonic signal generation unit.

上記のとおり構成した本発明の自励式無効電力補償装置1は、直流電圧制御系と系統電圧制御系から構成されている。 The self-excited reactive power compensating device 1 of the present invention configured as described above is composed of a DC voltage control system and a system voltage control system.

系統電圧制御系は、系統電圧制御部2、逆γδ変換・逆αβ変換部3、電流出力部4、計器用変成器VTおよび系統電圧検出部10から構成される。自励式無効電力補償装置1の出力電流指令値は、前記2つの制御系の補償器の出力を逆γδ変換・逆αβ変換することにより作成される。そして、電流出力部4は、当該出力電流指令値に応じた電流を配電線に出力し、無効電力を供給する。 The system voltage control system is composed of a system voltage control unit 2, an inverse γδ conversion / inverse αβ conversion unit 3, a current output unit 4, an instrument transformer VT, and a system voltage detection unit 10. The output current command value of the self-excited reactive power compensator 1 is created by performing inverse γδ conversion and inverse αβ conversion of the outputs of the compensators of the two control systems. Then, the current output unit 4 outputs a current corresponding to the output current command value to the distribution line and supplies reactive power.

以上のように構成した自励式無効電力補償装置1において、補償器2の定数を決定する場合、まず、配電線のインピーダンスを計測する。計測にあたっては、該無効電力補償装置1から次数間高調波(例えば、2.5次)の微小電流を配電系統に注入する。 In the self-excited reactive power compensator 1 configured as described above, when determining the constant of the compensator 2, the impedance of the distribution line is first measured. In the measurement, a minute current of inter-degree harmonics (for example, 2.5th order) is injected from the reactive power compensator 1 into the distribution system.

次数間高調波電流検出部5は、電流検出器CTで検出した電流i(t)(電流出力部4から出力される電流)と次数間高調波信号生成部12が出力する次数間高調波信号を入力として、下記[数1]によって次数間高調波電流Ikのcos成分とsin成分を求め、下記[数2]によって次数間高調波電流Ikを求める。 The inter-order harmonic current detection unit 5 includes the current i (t) (current output from the current output unit 4) detected by the current detector CT and the inter-order harmonic signal output by the inter-order harmonic signal generation unit 12. Is used as an input, the cos component and sin component of the interorder harmonic current Ik are obtained by the following [Equation 1], and the interorder harmonic current Ik is obtained by the following [Equation 2].

次数間高調波電圧検出部6は、計器用変成器VTで検出した電圧v(t)(自励式無効電力補償装置1が接続されている点の配電線の電圧)と次数間高調波信号生成部12が出力する次数間高調波信号を入力として、下記[数3]によって次数間高調波電圧Vkのcos成分とsin成分を求め、下記[数4]によって次数間高調波電圧Vkを求める。 The inter-order harmonic voltage detection unit 6 generates a harmonic signal between the order voltage v (t) (voltage of the distribution wire at the point where the self-excited ineffective power compensator 1 is connected) detected by the instrument transformer VT. Taking the interorder harmonic signal output by the unit 12 as an input, the cos component and the sin component of the interorder harmonic voltage Vk are obtained by the following [Equation 3], and the interorder harmonic voltage Vk is obtained by the following [Equation 4].

次に、配電線インピーダンス演算部7は、次数間高調波電流検出部5によって求めた次数間高調波電流Ikと、次数間高調波電圧検出部6によって求めた次数間高調波電圧Vkを入力として配電線インピーダンスZlを求める。 Next, the distribution line impedance calculation unit 7 inputs the inter-order harmonic current Ik obtained by the inter-order harmonic current detection unit 5 and the inter-order harmonic voltage Vk obtained by the inter-order harmonic voltage detection unit 6. Obtain the distribution line impedance Zl.

配電線インピーダンスZl=R+jX(R:配電線インピーダンスの抵抗分、X:配電線インピーダンスのリアクタンス分)とすると、次数間高調波におけるインピーダンスZlkは下記[数5]のようになる。 Assuming that the distribution line impedance Zl = R + jX (R: the resistance of the distribution line impedance and X: the reactance of the distribution line impedance), the impedance Zlk in the interorder harmonics is as shown in [Equation 5] below.

また、次数間高調波におけるインピーダンスZlkは下記[数6]で計算できる。 Further, the impedance Zlk in the inter-degree harmonic can be calculated by the following [Equation 6].

したがって、配電線インピーダンスは下記[数7]によって求めることができる。 Therefore, the distribution line impedance can be obtained by the following [Equation 7].

最後に、計算誤差を小さくするため、求めた配電線インピーダンスを平均化する。平均化した値が配電線インピーダンスの計測値となる。 Finally, in order to reduce the calculation error, the obtained distribution line impedance is averaged. The averaged value is the measured value of the distribution line impedance.

配電線インピーダンスの計測値は、補償器定数決定部8に出力され、補償器定数決定部8は配電線インピーダンスの計測値に基づき補償器定数の最適値を決定する。 The measured value of the distribution line impedance is output to the compensator constant determination unit 8, and the compensator constant determination unit 8 determines the optimum value of the compensator constant based on the measured value of the distribution line impedance.

補償器定数の最適値は、系統電圧制御系の周波数特性から決定する。一般に、制御系の制御精度や応答性、安定性(発振する・しない)は、制御系の周波数特性で決まる。配電線のインピーダンスに応じて補償器2の定数を調整することにより、系統電圧制御系の周波数特性を最適(安定かつ応答速度が速く、制御精度が良い)なものにすることができる。 The optimum value of the compensator constant is determined from the frequency characteristics of the system voltage control system. In general, the control accuracy, responsiveness, and stability (oscillation / non-oscillation) of a control system are determined by the frequency characteristics of the control system. By adjusting the constant of the compensator 2 according to the impedance of the distribution line, the frequency characteristics of the system voltage control system can be optimized (stable, fast response speed, and good control accuracy).

種々のインピーダンス値に対して、系統電圧制御系の周波数特性を最適なものにする補償器2の定数をあらかじめ把握しておく。この関係性から、補償器定数の最適値を決定することができる。 The constant of the compensator 2 that optimizes the frequency characteristics of the system voltage control system for various impedance values is grasped in advance. From this relationship, the optimum value of the compensator constant can be determined.

上記のごとく決定した補償器定数は系統電圧制御部2に出力され、補償器の定数が自動的に最適値に設定される。 The compensator constant determined as described above is output to the system voltage control unit 2, and the compensator constant is automatically set to the optimum value.

以上説明したように、本発明の自励式無効電力補償装置によれば、制御系の補償器の定数を決めるにあたり、事前に配電線のインピーダンスを調査する必要がない。 As described above, according to the self-excited reactive power compensator of the present invention, it is not necessary to investigate the impedance of the distribution line in advance when determining the constant of the compensator of the control system.

また、系統切換などで配電線のインピーダンスが大きく変化した場合でも、補償器の定数は自動的に最適値に変更されるので、従来のように手動で補償器定数の設定を変更する必要がない。 In addition, even if the impedance of the distribution line changes significantly due to system switching, the compensator constant is automatically changed to the optimum value, so there is no need to manually change the compensator constant setting as in the past. ..

本発明は、配電線のインピーダンスに応じて調整動作や制御動作を行う配電用機器に利用可能である。 INDUSTRIAL APPLICABILITY The present invention can be used for a power distribution device that performs an adjustment operation or a control operation according to the impedance of a distribution line.

1 自励式無効電力補償装置
2 系統電圧制御部(補償器)
3 逆γδ変換・逆αβ変換部
4 電流出力部
5 次数間高調波電流検出部
6 次数間高調波電圧検出部
7 配電線インピーダンス演算部
8 補償器定数決定部
9 次数間高調波電流指令値生成部
10 系統電圧検出部
11 PLL
12 次数間高調波信号生成部
1 Self-excited reactive power compensator 2 System voltage control unit (compensator)
3 Inverse γδ conversion / Inverse αβ conversion unit 4 Current output unit 5 Interorder harmonic current detection unit 6 Interorder harmonic voltage detection unit 7 Distribution wire impedance calculation unit 8 Compensator constant determination unit 9 Interorder harmonic current command value generation Unit 10 System voltage detector 11 PLL
12th degree harmonic signal generator

Claims (2)

各地の高圧配電線系統のインピーダンス値に対して、系統電圧制御系の周波数特性を基に補償器定数をあらかじめ計算しておき、こうして把握しておいた補償器定数を、配電線インピーダンス値の自動計測結果に基づき自動で設定することを特徴とする自励式無効電力補償装置。 For the impedance value of the high-voltage distribution line system in each region , the compensator constant is calculated in advance based on the frequency characteristics of the system voltage control system, and the compensator constant thus grasped is automatically used as the distribution line impedance value. A self-excited reactive power compensator that automatically sets based on the measurement results. 前記自励式無効電力補償装置から次数間高調波の微小電流を配電系統に注入して、系統電圧の同次数の高調波を計測することで、下記式(1)で次数間高調波電流を求め、下記式(2)で次数間高調波電圧を求め、これらを入力として下記式(3)で前記配電線インピーダンスを求め、これを平均化することにより、平均化した値を前記配電線インピーダンス値と自動推定することを特徴とする請求項1記載の自励式無効電力補償装置:
式(1)
By injecting a minute current of interorder harmonics into the distribution system from the self-excited ineffective power compensator and measuring the harmonics of the same order of the system voltage, the interorder harmonic current is obtained by the following equation (1). , The inter-order harmonic voltage is obtained by the following formula (2), the distribution line impedance is obtained by the following formula (3) using these as inputs, and the averaged value is obtained by averaging the distribution line impedance value. The self-excited ineffective power compensator according to claim 1, wherein the self-excited ineffective power compensator is automatically estimated.
Equation (1)
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JP6638080B2 (en) * 2016-10-13 2020-01-29 株式会社日立製作所 Power system impedance measuring device and method, and power system power factor improving device and method
JP2018107877A (en) * 2016-12-26 2018-07-05 愛知電機株式会社 Reactive power compensation apparatus and power system voltage control method using the same

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