JPS61125628A - Method and device for compensating reactive electric power - Google Patents
Method and device for compensating reactive electric powerInfo
- Publication number
- JPS61125628A JPS61125628A JP24664084A JP24664084A JPS61125628A JP S61125628 A JPS61125628 A JP S61125628A JP 24664084 A JP24664084 A JP 24664084A JP 24664084 A JP24664084 A JP 24664084A JP S61125628 A JPS61125628 A JP S61125628A
- Authority
- JP
- Japan
- Prior art keywords
- current
- reactive
- compensation
- reactive current
- reactive power
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Links
Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05F—SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
- G05F1/00—Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems
- G05F1/70—Regulating power factor; Regulating reactive current or power
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- General Physics & Mathematics (AREA)
- Radar, Positioning & Navigation (AREA)
- Automation & Control Theory (AREA)
- Control Of Electrical Variables (AREA)
Abstract
Description
【発明の詳細な説明】
〔発明の技術分野〕
本発明は、電源系統の総合力率がほぼ1になるよう制御
づる無効電力補償方法およびそのための装置に関する。DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a reactive power compensation method and apparatus for controlling the total power factor of a power supply system to approximately 1.
系統を経済的に運用し、安定度を向上するために、無効
電力補償装置が従来から広く使用されている。その中で
特に近年は、!、II tit性の良いパルス幅変調形
(以下PWM形と記す)の自助変換器を用いた無効電力
補償装置が注目されている。以下、添付図面の第3図お
よび第4図を参照して従来装置を説明する。なお、図面
の説明において同一の要素は同一の符号で示す。In order to operate the grid economically and improve stability, reactive power compensators have been widely used. Especially in recent years! , II A reactive power compensator using a pulse width modulation type (hereinafter referred to as PWM type) self-help converter with good titability is attracting attention. The conventional device will be described below with reference to FIGS. 3 and 4 of the accompanying drawings. In addition, in the description of the drawings, the same elements are indicated by the same reference numerals.
第3図は従来装置の一例の構成図である。電源系統1に
は無効電力の発生源となる負荷2と、無効電力補償装置
と系統1を絶縁するための変圧器3とが接続されている
。また変圧器3には自己消弧型素子により構成されるP
WM変換鼎4と、等衛的に直流電圧源となるコンデンサ
5と、コンデンサ5の両端間の電圧を検出する直流電圧
検出器6とが接続されている。また変換器3とPWM変
換器4の間には無効電力補償装置自身の電流を検出する
電流検出器7が介挿されているゆさらに系統1には負荷
2に流れる負荷電流を検出するffi流検比検出器8系
統1の電圧を検出する電圧検出器9とが設けられ、これ
らの出力は無効1!流変挽回路10に与えられている。FIG. 3 is a configuration diagram of an example of a conventional device. Connected to the power supply system 1 are a load 2 serving as a source of reactive power, and a transformer 3 for insulating the system 1 from the reactive power compensator. In addition, the transformer 3 has a P
The WM converter 4 is connected to a capacitor 5 which serves as a direct current voltage source, and a direct current voltage detector 6 which detects the voltage across the capacitor 5. Furthermore, a current detector 7 is inserted between the converter 3 and the PWM converter 4 to detect the current of the reactive power compensator itself. A voltage detector 9 that detects the voltage of the ratio detector 8 system 1 is provided, and these outputs are invalid 1! It is given to the flow variation circuit 10.
P W M i/I I11回路11は、電圧fI11
w回路12の出力と無効!!流変換回路10の出力と電
流検出器7の出力にもとづいてPWM変換器4ヲ1lJ
IXlt6゜
次に第3図の構成例の動作を説明する。The P W M i/I I11 circuit 11 has a voltage fI11
w Circuit 12 output and invalidity! ! Based on the output of the current conversion circuit 10 and the output of the current detector 7, the PWM converter 4 is
IXlt6° Next, the operation of the configuration example shown in FIG. 3 will be explained.
負荷電流と系統電圧とにもとづいて無効電流変換回路1
0は補償ずべき無効電流を求める。さらに直流電源を構
成するコンデンサ5の電圧は電圧検出器6で検出され、
加減算器15にて基準値E とつきあわされて電圧制
W回路12に入力er
される。このようにして直流電圧を一定に保つような補
@電流が得られる。さらに、この補償71i流(電圧I
I御回路12の出力)と先の補償すべき無効電流(無効
電流変換回路10の出力)との和と、無効電力補償装置
自身の発生する電流(111%E検出器7の出力)とが
加減算器16にてつきあわされて、P W M IIJ
90回路11に与えられる。これによってPWM変換
器を構成する各素子がオン、オフさせられ、補償すべき
無効電流が発生させられる。Reactive current conversion circuit 1 based on load current and grid voltage
0 determines the reactive current to be compensated. Furthermore, the voltage of the capacitor 5 constituting the DC power supply is detected by a voltage detector 6,
It is matched with the reference value E by the adder/subtractor 15 and inputted to the voltage control W circuit 12. In this way, a supplementary current is obtained that keeps the DC voltage constant. Furthermore, this compensation 71i current (voltage I
The sum of the reactive current to be compensated (output of the I control circuit 12), the reactive current to be compensated for (output of the reactive current conversion circuit 10), and the current generated by the reactive power compensator itself (output of the 111% E detector 7). It is matched by the adder/subtractor 16, and P
90 circuit 11. As a result, each element constituting the PWM converter is turned on and off, and a reactive current to be compensated is generated.
第4図は第3図に示す構成例の補償1:流の波形図であ
る。負荷2に流れる電流は曲線Aのようになっている。FIG. 4 is a waveform diagram of compensation 1: flow in the configuration example shown in FIG. The current flowing through load 2 is as shown by curve A.
それに対して無効電力補償装置から供給される補償電流
は、のこぎり状の折れ線Bのようになっている。このた
め、無効電流は補償されて総合力率はほぼ1にされる。On the other hand, the compensation current supplied from the reactive power compensator is like a sawtooth broken line B. Therefore, the reactive current is compensated and the overall power factor is made approximately 1.
ところで、一般に負荷に流れる電流には、高調波の無効
電流分と、基本波の無効電流分が含まれている。従って
総合力率を常に1にするためには、14調波の無効電流
分と基本波の無効電流分を無効電力補償装置で供給しな
ければならない。ここで問題となる高調波の周波数は、
基本波の5次、7次、11次、13次であることが多い
ので、これらの1&調波を611611するには、PW
M形変換器を構成する自己消弧型素子のスイッチング周
波数を十分高くしなければ満足する特性が得られない。Incidentally, the current flowing through the load generally includes a harmonic reactive current component and a fundamental wave reactive current component. Therefore, in order to always keep the overall power factor at 1, the reactive current of the 14th harmonic and the reactive current of the fundamental wave must be supplied by the reactive power compensator. The harmonic frequency that is the problem here is
These are often the 5th, 7th, 11th, and 13th orders of the fundamental wave, so to 611611 these 1 & harmonics, use PW
Satisfactory characteristics cannot be obtained unless the switching frequency of the self-extinguishing element constituting the M-type converter is made sufficiently high.
また負荷の?ti流には一般に高調波無効電流よりも基
本波無効電流の方が多く含まれているため、無効電力補
償装置の容量は大きなものとなってしまう。Also of load? Since the ti current generally contains more fundamental wave reactive current than harmonic reactive current, the capacity of the reactive power compensator ends up being large.
従って、基本波の無効電流と高調波の無効電流を同時に
補償するためには高周波で運転しなければならず、その
上大容量が要求されるためPWM変換器を構成する素子
の並列数を多くしたり、変換器を多重化したりしなけれ
ばならない。そのため素子のスイッチング損失が増加し
、さらに素子を保護するために使用されるスナバ回路の
損失及び変圧器の損失が著しく増加してしまう。Therefore, in order to simultaneously compensate for the reactive current of the fundamental wave and the reactive current of the harmonics, it is necessary to operate at a high frequency, and in addition, a large capacity is required, so the number of parallel elements that make up the PWM converter is increased. or multiplex the converters. Therefore, the switching loss of the element increases, and furthermore, the loss of the snubber circuit and the loss of the transformer used to protect the element increase significantly.
以上のことより従来技術では、装置自体が大型化し効率
が低いという問題がある。As described above, the conventional technology has the problem that the device itself becomes large and the efficiency is low.
(発明の目的)
本発明は上記の従来技術の欠点を克服するためになされ
たもので、変圧器およびスナバ回路における罰失が少な
く高効率で、かつ装W1規模を小望にすることのできる
無効電力補償方法およびそのための装置を提供すること
を目的とする。(Object of the Invention) The present invention has been made to overcome the drawbacks of the above-mentioned prior art, and it is possible to achieve high efficiency with less loss in the transformer and snubber circuit, and to reduce the size of the W1 system. An object of the present invention is to provide a reactive power compensation method and a device therefor.
上記の目的を達成するため本発明は、系統に接続された
負荷により発生させられる無効N81を基本波(低周波
)成分と高調波(高周波)成分に分離し、前者について
は低周波P W M IJ IIIで補償し、後者につ
いては高周波P W M ill IIIで補償するよ
うにした無効電力補償方法およびそのための装置を提供
するものである。In order to achieve the above object, the present invention separates the reactive N81 generated by the load connected to the grid into a fundamental (low frequency) component and a harmonic (high frequency) component, and for the former, the low frequency P W M The present invention provides a reactive power compensation method in which compensation is performed using IJ III, and the latter is compensated using high frequency PW Mill III, and a device therefor.
(発明の実施例)
以下、添付図面の第1図および第2図を参照して本発明
の一実施例を説明する。第1図は同実施例の構成図であ
る。第3図と比較すれば明らかなように、点線で囲んだ
基本波無効電力補償装置14は第1図の回路と同じにな
っている。また高調波無効電力補償装置14′も基本構
成は同じである。第3図と異なり第1図では、無効電流
変換回路10の出力側にバンドパスフィルタ13が接続
され、無効電流変換回路10の出力とバンドパスフィル
タ13を通過した信号は加減算器17で減算される。(Embodiment of the Invention) Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2 of the accompanying drawings. FIG. 1 is a block diagram of the same embodiment. As is clear from a comparison with FIG. 3, the fundamental wave reactive power compensator 14 surrounded by the dotted line is the same as the circuit shown in FIG. Further, the basic configuration of the harmonic reactive power compensator 14' is the same. Unlike FIG. 3, in FIG. 1, a bandpass filter 13 is connected to the output side of the reactive current conversion circuit 10, and the output of the reactive current conversion circuit 10 and the signal passed through the bandpass filter 13 are subtracted by an adder/subtractor 17. Ru.
次に第1図に示す実施例の作用を説明する。電流検出器
8と電圧検出!i9で得られた負荷電流と系統電圧にも
とづいて、無効wi流変換回路10によって補償すべき
無効電流が求められる。この無効電流は基本周波成分の
みを通すようにしたバンドパスフィルタ13に入力され
、基本波無効電流のみが取り出される。この基本波無効
電流は電圧617111回路12から与えられる補償電
流(コンデンサ5の直流電圧を一定に保つもの)と加算
され、基本波無効電力補償装[14自身の電流との差が
加減III器16からPWMM11回路11に与えられ
、基本波無効電力補償装置114にて基本波無効電力を
補償する。この場合には、基本周波成分の無効1!流の
み補償すればよ゛い6ら、PWM変換器4を構成する素
子のスイッチング周波数は低くすることができる。Next, the operation of the embodiment shown in FIG. 1 will be explained. Current detector 8 and voltage detection! Based on the load current and system voltage obtained in step i9, the reactive current to be compensated for is determined by the reactive current conversion circuit 10. This reactive current is input to a band pass filter 13 that allows only the fundamental frequency component to pass, and only the fundamental reactive current is extracted. This fundamental wave reactive current is added to the compensation current given from the voltage 617111 circuit 12 (which keeps the DC voltage of the capacitor 5 constant), and the difference with the current of the fundamental wave reactive power compensator [14] is added to the compensation current given by the voltage 617111 circuit 12. is applied to the PWMM 11 circuit 11, and the fundamental wave reactive power is compensated by the fundamental wave reactive power compensator 114. In this case, the fundamental frequency component is invalid 1! Since only the current needs to be compensated for, the switching frequency of the elements constituting the PWM converter 4 can be lowered.
一方高調波無効電流は、加減IJ器17にて無効電流変
換回路10の出力からバンドパスフィルタ13の出力の
差を求めることによって得られる。On the other hand, the harmonic reactive current is obtained by calculating the difference between the output of the bandpass filter 13 and the output of the reactive current conversion circuit 10 using the adder/subtractor IJ device 17.
この高調波無効if流は電圧制御回路12から与えられ
る補償N流(コンデンサ5′)の直流電圧を一定に保つ
もの)と加算され、高調波無効電力補償装置14′自身
の電流(i流検出器7′の出力)との差が加減*器16
′からP W M ill a11回路11に与えられ
る。このようにしてat14波無効電力補演装置14’
は、all波分の無効電流を補償する。This harmonic reactive power if current is added to the compensation N current given from the voltage control circuit 12 (which keeps the DC voltage of the capacitor 5' constant), and the current of the harmonic reactive power compensator 14' itself (i current detected The difference between the output of unit 7' and
' to the PWM ill a11 circuit 11. In this way, the at14-wave reactive power supplementary device 14'
compensates for the reactive current of all waves.
なおこの場合には、高調波成分の無効電流を補償するの
であるから、PWM変換器4′を構成する素子のスイッ
チング周波数は十分高くする必要がある。In this case, since the reactive current of harmonic components is compensated for, the switching frequency of the elements constituting the PWM converter 4' needs to be sufficiently high.
第2図は補償電流の波形図であり、第2図<a>は基本
波成分と高調波成分を分離する鷹前の従来例によるもの
を示し、第2図(b)は本実施例による基本波成分のみ
を示し、第2図(C)は本実施例による高調波成分のみ
を示している。第2図(b)、(c)に示すように、基
本波無効電流A1は基本波無効電力補償装置14による
補償電流B1によって補償され、a調波無効電流A2は
高調波無効電力補償装置14’による補償電流B2によ
って補償される。このようにして、系統の総合力率は1
に保たれる。Fig. 2 is a waveform diagram of the compensation current, Fig. 2 <a> shows the conventional example by Takamae that separates the fundamental wave component and the harmonic component, and Fig. 2 (b) shows the waveform of the present embodiment. Only the fundamental wave component is shown, and FIG. 2(C) shows only the harmonic component according to this embodiment. As shown in FIGS. 2(b) and 2(c), the fundamental wave reactive current A1 is compensated by the compensation current B1 by the fundamental wave reactive power compensator 14, and the a-harmonic reactive current A2 is compensated by the harmonic reactive power compensator 14. ' is compensated by compensation current B2. In this way, the overall power factor of the system is 1
is maintained.
このように本実施例によれば、一般に高調波無効電力よ
りb大容量である基本波無効電力を補償する基本波無効
電力補償装M14のスイッチング周波数を十分低くづる
ことが可能であるため、スイッチング周波数に比例する
素子のスイッチング損失や、素子を過電圧から保護する
スナバ回路の損失(一般にこの損失の全損失中に占める
割合が最も大きい)を低減することができる。また、ス
イッチング周波数に基因する高調波による変圧器の損失
も十分に低減することができる。As described above, according to this embodiment, it is possible to set the switching frequency of the fundamental wave reactive power compensator M14 that compensates for the fundamental wave reactive power, which generally has a larger capacity than the harmonic reactive power, sufficiently low, so that the switching It is possible to reduce the switching loss of the element, which is proportional to the frequency, and the loss of the snubber circuit that protects the element from overvoltage (generally, this loss accounts for the largest proportion of the total loss). Further, transformer loss due to harmonics caused by the switching frequency can also be sufficiently reduced.
なお、上記の実施例では電圧形のPWM変換器を用いて
いるが、電流形のPWM変換器を用いることができるこ
とは言うまでもない。Note that although a voltage-type PWM converter is used in the above embodiment, it goes without saying that a current-type PWM converter can also be used.
(発明の効果)
上記の如く本発明によれば、系統に接続された負荷によ
り発生させられる無効電流を基本波(低周波)成分と高
調波(ii周波)成分に分離し、比較的小容量の前者に
ついては低周波P W M III ilDで補償し、
比較的小容量の後者については高周波PWM訓御で補償
するようにしたので、変圧器およびスナバ回路における
損失が少なく高効率で、かつ装置規模を小型にすること
のできる無効電力補償方法およびそのための装置を提供
することができる。(Effects of the Invention) As described above, according to the present invention, the reactive current generated by the load connected to the grid is separated into the fundamental wave (low frequency) component and the harmonic (II frequency) component, and the capacity is relatively small. The former is compensated for by the low frequency P W M III ilD,
Since the latter, which has a relatively small capacity, is compensated by high-frequency PWM control, we have developed a reactive power compensation method that has low loss in transformers and snubber circuits, is highly efficient, and can reduce the size of the device. equipment can be provided.
第1図は本発明の一実施例の構成図、第2図は従来例お
よび第1図に示す実施例による補償電流の波形図、第3
図は従来装置の一例の構成図、第4図は第3図に示す構
成例の補償電流の波形図である。
1・・・電源系統、2・・・負荷、3.3′・・・変圧
鼎、4.4’ ・PWM’aafi、5 、5 ’ −
D ンテ:/ サ、6.6′・・・直流電圧検出器、7
.7’ 8・・・電流検出器、9・・・電圧検出器、1
0・・・無効電流変換回路、11.11’ ・・・P
W M i制御回路、12・・・電圧lll111回路
、13・・・バンドパスフィルタ、14・・・基本波無
効電力補償装置、14′・・・高講波無効電力補償装M
。FIG. 1 is a configuration diagram of an embodiment of the present invention, FIG. 2 is a waveform diagram of compensation current according to the conventional example and the embodiment shown in FIG. 1, and FIG.
This figure is a configuration diagram of an example of a conventional device, and FIG. 4 is a waveform diagram of a compensation current in the configuration example shown in FIG. 3. 1...Power system, 2...Load, 3.3'...Transformer, 4.4'・PWM'aafi, 5, 5'-
D nt:/sa, 6.6'...DC voltage detector, 7
.. 7' 8...Current detector, 9...Voltage detector, 1
0...Reactive current conversion circuit, 11.11'...P
W M i control circuit, 12... Voltage lll111 circuit, 13... Bandpass filter, 14... Fundamental wave reactive power compensator, 14'... High wave reactive power compensator M
.
Claims (1)
流を、この系統に補償電流を供給することによって補償
する無効電力補償方法において、前記無効電流の基本周
波成分は、第1のPWM変換器による低周波PWM制御
によつて前記補償電流の基本周波成分を前記系統に供給
することにより補償し、 前記無効電流の高調波成分は、前記第1のPWM変換器
とは搬送周波数が異なる第2のPWM変換器による高周
波PWM制御によつて、前記補償電流の高調波成分を前
記系統に供給することにより補償するようにしたことを
特徴とする無効電力補償方法。 2、系統に供給される電圧と負荷に流れる電流とにもと
づいて補償すべき無効電流を求める無効電流変換手段と
、この補償すべき無効電流の基本周波成分である基本波
無効電流のみを通過させるフィルタと、前記補償すべき
無効電流から前記基本波無効電流を減じることにより、
この補償すべき無効電流の高調波成分である高調波無効
電流を出力する手段と、第1のPWM変換器を有し、前
記基本波無効電流にもとづいてこの第1のPWM変換器
を制御することにより、補償電流の基本周波成分を前記
系統に供給する基本波無効電力補償手段と、第2のPW
M変換器を有し、前記高調波無効電流にもとづいてこの
第2のPWM変換器を制御することにより、前記補償電
流の高調波成分を前記系統に供給する高調波無効電力補
償手段とを備える無効電力補償装置。[Claims] 1. In a reactive power compensation method for compensating for a reactive current generated by a load connected to a grid by supplying a compensation current to the grid, the fundamental frequency component of the reactive current is The compensation is performed by supplying the fundamental frequency component of the compensation current to the system through low frequency PWM control by the first PWM converter, and the harmonic component of the reactive current is A reactive power compensation method, characterized in that compensation is performed by supplying harmonic components of the compensation current to the system through high-frequency PWM control using a second PWM converter having a different frequency. 2. Reactive current conversion means for determining the reactive current to be compensated based on the voltage supplied to the grid and the current flowing through the load, and passing only the fundamental reactive current that is the fundamental frequency component of the reactive current to be compensated. filter and subtracting the fundamental reactive current from the reactive current to be compensated,
It has means for outputting a harmonic reactive current that is a harmonic component of the reactive current to be compensated, and a first PWM converter, and controls the first PWM converter based on the fundamental reactive current. By this, fundamental wave reactive power compensating means for supplying the fundamental frequency component of the compensation current to the system, and the second PW
A harmonic reactive power compensation means having an M converter and supplying harmonic components of the compensation current to the system by controlling the second PWM converter based on the harmonic reactive current. Reactive power compensator.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP24664084A JPS61125628A (en) | 1984-11-21 | 1984-11-21 | Method and device for compensating reactive electric power |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP24664084A JPS61125628A (en) | 1984-11-21 | 1984-11-21 | Method and device for compensating reactive electric power |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS61125628A true JPS61125628A (en) | 1986-06-13 |
Family
ID=17151414
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP24664084A Pending JPS61125628A (en) | 1984-11-21 | 1984-11-21 | Method and device for compensating reactive electric power |
Country Status (1)
Country | Link |
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JP (1) | JPS61125628A (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6428712A (en) * | 1987-07-24 | 1989-01-31 | Mitsubishi Electric Corp | Active filter device |
US4857821A (en) * | 1987-03-27 | 1989-08-15 | Mitsubishi Denki Kabushiki Kaisha | Reactive power compensation system |
JPH01206418A (en) * | 1988-02-12 | 1989-08-18 | Nissin Electric Co Ltd | Reactive power compensator using invertor |
JP2011115018A (en) * | 2009-11-30 | 2011-06-09 | Toshiba Mitsubishi-Electric Industrial System Corp | Self-exciting reactive-power compensator |
-
1984
- 1984-11-21 JP JP24664084A patent/JPS61125628A/en active Pending
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4857821A (en) * | 1987-03-27 | 1989-08-15 | Mitsubishi Denki Kabushiki Kaisha | Reactive power compensation system |
JPS6428712A (en) * | 1987-07-24 | 1989-01-31 | Mitsubishi Electric Corp | Active filter device |
JPH01206418A (en) * | 1988-02-12 | 1989-08-18 | Nissin Electric Co Ltd | Reactive power compensator using invertor |
JP2011115018A (en) * | 2009-11-30 | 2011-06-09 | Toshiba Mitsubishi-Electric Industrial System Corp | Self-exciting reactive-power compensator |
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