JPS593103B2 - Unbalanced load correction device - Google Patents
Unbalanced load correction deviceInfo
- Publication number
- JPS593103B2 JPS593103B2 JP52081624A JP8162477A JPS593103B2 JP S593103 B2 JPS593103 B2 JP S593103B2 JP 52081624 A JP52081624 A JP 52081624A JP 8162477 A JP8162477 A JP 8162477A JP S593103 B2 JPS593103 B2 JP S593103B2
- Authority
- JP
- Japan
- Prior art keywords
- load
- phase
- current
- dummy
- unbalanced
- 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.)
- Expired
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- Supply And Distribution Of Alternating Current (AREA)
Description
【発明の詳細な説明】
この発明は、電源回路に接続された負荷が変動して３相
電力に不平衡が正じた場合に電源に対して負荷が平衡す
るように補正する不平衡負荷補正装置に関するものであ
る。Detailed Description of the Invention This invention provides unbalanced load correction that corrects the load so that it is balanced with respect to the power supply when the load connected to the power supply circuit fluctuates and unbalance is corrected in three-phase power. It is related to the device.
不平衡負荷補正装置は、負荷の不平衡を補正して電源に
対する不平衡を補正する装置であつて、従来、この種装
置としては第１図に示すような不平衡負荷補正装置があ
る。An unbalanced load correction device is a device that corrects the unbalance of a load to correct the unbalance with respect to a power supply. Conventionally, an unbalanced load correction device as shown in FIG. 1 is an example of this type of device.
同図において１は電源、２は電源母線、３は電 。In the figure, 1 is a power supply, 2 is a power bus, and 3 is a power supply.
源母線２に接続された負荷、４はダミーロード用Ｒ相開
閉器、５はダミーロード用Ｓ相開閉器、６はダミーロー
ド用Ｔ相開閉器、Ｔはダミーロードである。ダミーロー
ドＴは開閉器４、５、６、、を通じて電源母線２に接続
されている。８は不平衡 。Loads connected to the source bus 2 include a dummy load R-phase switch 4, a dummy load S-phase switch 5, a dummy load T-phase switch 6, and a dummy load T. The dummy load T is connected to the power supply bus 2 through switches 4, 5, 6, . 8 is unbalanced.
検出装置で、負荷３の不平衡状態を検出し、必要に応じ
て開閉器４、５、６を開閉する信号を送出し、開閉器４
と５、開閉器５と６又は開閉器４と６のいずれかの組合
せでダミーロードを挿入する。このように構成された不
平衡負荷補正装置において、電源１より電源母線２を通
して負荷３に電５ 力が供給されているとき、何等かの
原因によつて負荷３が不平衡負荷となるが、不平衡検出
装置８がどの相の負荷が最も少ないかを検出し、各相開
閉器４、５、６のうちの２ケに投入信号を供給する。開
閉器４、５、６のうちの２ケが投入される″ｏ と、ダ
ミーロード７は単相負荷として電源母線２に接続される
こととなり、電源１に対して負荷３が平衡負荷であるか
に見せる。この結果、電源より供給される電流の逆相分
がこれに伴なつて減少し、逆相電圧が減少して不平衡負
荷を補正するこ″５ とにより、発電機の極部過熱およ
び異常振動を防止する。しかしながら、上述した不平衡
負荷補正装置は、ダミーロードが単相負荷としてのみ作
用するために、逆相電流の減少は余り期待できず、逆相
電圧フ０ に至つては、不平衡程度によつてはかえつて
悪化させてしまう等の欠点を有している。The detection device detects the unbalanced state of the load 3 and sends a signal to open and close the switches 4, 5, and 6 as necessary.
and 5, insert a dummy load using any combination of switches 5 and 6 or switches 4 and 6. In the unbalanced load correction device configured as described above, when power is supplied from the power supply 1 to the load 3 through the power supply bus 2, the load 3 becomes an unbalanced load for some reason. The unbalance detection device 8 detects which phase has the least load and supplies a closing signal to two of the phase switches 4, 5, and 6. When two of the switches 4, 5, and 6 are turned on, the dummy load 7 is connected to the power supply bus 2 as a single-phase load, and the load 3 is a balanced load for the power supply 1. As a result, the negative-sequence component of the current supplied from the power supply decreases accordingly, and the negative-sequence voltage decreases, correcting the unbalanced load. Prevent overheating and abnormal vibration. However, with the above-mentioned unbalanced load correction device, since the dummy load acts only as a single-phase load, it is not expected that the negative sequence current will decrease much, and the negative sequence voltage F0 will depend on the degree of unbalance. It has the disadvantage that it may even make things worse.
従つて、この発明による目的は、Ｖ結線によるダミーロ
ードを電源母線に接続することにより逆相電流および逆
相電圧を大幅に減少させて不平衡ノ５ 負荷を補正する
不平衡負荷補正装置を提供することである。Therefore, an object of the present invention is to provide an unbalanced load correction device that corrects an unbalanced load by significantly reducing negative sequence current and negative sequence voltage by connecting a dummy load with a V connection to a power supply bus. It is to be.
以下、図面を用いてこの発明による不平衡負荷補正装置
を詳細に説明する。Hereinafter, the unbalanced load correction device according to the present invention will be explained in detail using the drawings.
第２図はこの発明による不平衡負荷補正装置の１０−実
施例を示す回路図であつて、第１図と同一部分は同記号
を用いてある。FIG. 2 is a circuit diagram showing a tenth embodiment of the unbalanced load correcting device according to the present invention, and the same parts as in FIG. 1 are designated by the same symbols.
同図において９はダミーロードＡＯ）Ｒ相開閉器、１０
はダミーロードＡのＳ相開閉器、１１はダミーロードＡ
のＴ相開閉器、１２はダミロードＡであつて、開閉器９
、１５１０、１１を通して電源母線２に接続されている
。このように構成された装置において、負荷３が不平衡
負荷の状態となると、不平衡検出装置８がどの相が最も
低負荷となつたかを検出して判定し、判定された相を中
心としてＶ結線負荷となるように開閉器４，５，６，９
，１０，１１の投入を制御する。例えば、Ｒ相が最も低
負荷になると、ダミーロード７の開閉器４と５及びダミ
ーロードＡｌ２の開閉器９と１１が投入されてダミーロ
ード７でＲ−Ｓ相、ダミーロードＡｌ２でＲ−Ｔ相の負
荷となるように開閉器を投入制御する。この場合、ダミ
ーロード７においてＲ−Ｔ相、ダミーロードＡｌ２でＲ
−Ｓ相の負荷となるように制御しても同じであることは
言うまでもない。第３図は負荷３の電流、従来の装置に
おける補正後の電流、及びこの発明による補正後の電流
を示したベクトル図である。In the same figure, 9 is a dummy load AO) R phase switch, 10
is the S phase switch of dummy load A, 11 is dummy load A
The T-phase switch 12 is a dummy load A, and the switch 9
, 1510, 11 to the power supply bus 2. In the device configured in this way, when the load 3 becomes an unbalanced load state, the unbalance detection device 8 detects and determines which phase has the lowest load, and adjusts the V around the determined phase. Switches 4, 5, 6, 9 are connected so that the load is connected.
, 10, and 11 are controlled. For example, when the R phase becomes the lowest load, switches 4 and 5 of dummy load 7 and switches 9 and 11 of dummy load Al2 are closed, so that dummy load 7 has an R-S phase and dummy load Al2 has an R-T phase. The switch is controlled to close so that it becomes the phase load. In this case, the dummy load 7 has an R-T phase, and the dummy load Al2 has an R-T phase.
It goes without saying that the same result can be achieved even if the load is controlled to be a -S phase load. FIG. 3 is a vector diagram showing the current of the load 3, the current after correction in the conventional device, and the current after correction according to the present invention.
同図においてベクトル１３は負荷３のＲ相電流、ベクト
ル１４はＳ相電流、ベクトル１５はＴ相電流を示してい
る。In the figure, vector 13 indicates the R-phase current of the load 3, vector 14 indicates the S-phase current, and vector 15 indicates the T-phase current.
また、ベクトル１６は従来の補正後のＲ相電流、ベクト
ル１７はＳ相電流、ベクトル１８はＴ相電流であり、ま
たベクトル１９はこの発明による補正後のＲ相電流、ベ
クトル２０はＳ相電流、ベクトル２１はＴ相電流を示し
、従来の装置におけるダミーロード単相投入に比べてこ
の発明によるＶ結線の効果が極めて優れていることがわ
かる。Vector 16 is the R-phase current after the conventional correction, vector 17 is the S-phase current, vector 18 is the T-phase current, vector 19 is the R-phase current after the correction according to the present invention, and vector 20 is the S-phase current. , vector 21 indicates the T-phase current, and it can be seen that the effect of the V connection according to the present invention is extremely superior to the single-phase dummy load input in the conventional device.
次に、上述のＶ結線ダミーロードを用いたことによる不
平衡負荷の逆相電流、逆相電圧の改善できる理由につい
て、更に詳述する。この発明は、電気炉のような負荷の
とき、溶湯の局部的なわき上がりにより、１相のみ高イ
ンピーダンスとなることにより、不平衡負荷となつて逆
相電流が流れることに対する対策として発明されたもの
である。Next, the reason why the negative sequence current and negative sequence voltage of the unbalanced load can be improved by using the above-mentioned V-connection dummy load will be explained in more detail. This invention was invented as a countermeasure to the problem that when a load such as an electric furnace is used, local swelling of molten metal causes only one phase to become high impedance, resulting in an unbalanced load and negative sequence current flowing. It is something.
この場合の負荷電流は第４図に示すように表現される。The load current in this case is expressed as shown in FIG.
この第４図において、Ｅａｂはａ相とｂ相間の電圧、Ｅ
ｂｃはｂ相とｃ相間の電圧、Ｅｃａはａ相とｃ相間の電
圧である。また１ａ〜Ｉｃはそれぞれａ相〜ｃ相の電流
であり、Ｅａｃ，Ｚｂｃ，ＺｃａはそれぞれＡ，ｃ相間
、Ｂ，ｃ相間、Ｃ，ａ相間のインピーダンスであり、１
ａＢ，Ｉｂｃ，ＩｃａはそれぞれインピーダンスＺａｂ
，Ｚｂｃ，Ｚｃａに流れる電流を示す。いまａ相電極付
近で溶湯のわき上がりが起こると、ＺａｂｔＺｃａ＞Ｚ
ｂｃとなり、そのときの電圧、電流の関係は第５図のベ
クトル図および下記のようになる（負荷力率１．０とし
て）。In this Fig. 4, Eab is the voltage between the a phase and b phase, and E
bc is the voltage between the b-phase and c-phase, and Eca is the voltage between the a-phase and c-phase. Further, 1a to Ic are the currents of the a phase to c phase, respectively, and Eac, Zbc, and Zca are the impedances between the A and c phases, between the B and c phases, and between the C and a phases, respectively.
aB, Ibc, and Ica are each impedance Zab
, Zbc, and Zca. Now, if the molten metal rises near the a-phase electrode, ZabtZca>Z
bc, and the relationship between voltage and current at that time is as shown in the vector diagram in FIG. 5 and as shown below (assuming the load power factor is 1.0).
負荷２ｃａ″Ｔ′２ＪａｂであるのでＣ，ａ相間の電流
はＩｃａ−Ａｉａｂとなり線電流は、となる。Since the load is 2ca''T'2Jab, the current between the C and a phases is Ica-Aiab, and the line current is as follows.
このときの逆相電流は、 となる。The negative sequence current at this time is becomes.
またＶ結果ダミーロード２ｖの負荷電流は第６図および
第７図のベクトル図の如くになり、ダミーロード２ｖは
水抵抗として力率１．０である。Further, the load current of the dummy load 2v as a result of V is as shown in the vector diagrams of FIGS. 6 and 7, and the dummy load 2v has a power factor of 1.0 as water resistance.
また線電流は、である。Also, the line current is.
この時の逆相電流は、 である。The negative sequence current at this time is It is.
こ＼で上記の不平衡負荷の逆相電流とＶ結線ダミーロー
ドの逆相電流と加算すると、となる。Now, if we add the negative sequence current of the unbalanced load mentioned above and the negative sequence current of the V-connected dummy load, we get:
負荷力率１．０１ダミーロードカ率１．０であることか
ら１ａｂ（５１ａｂｖ同相であり、Ｉｂｃ．ＩＩｂｃＩ
ａ２ｋＩａｂである（ｋ−―−一としｋ〉１）。Since the load power factor is 1.01 and the dummy load power factor is 1.0, 1ab (51abv is in phase, Ibc.IIbcI
a2kIab (k---1 and k>1).
１１ａｂ１ ｋ〉１故１ｚ−０のためには｛ ｝＝０ であればよい。11ab1 Since k〉1, for 1z-0, { }=0 That's fine.
とすると、
上記は、ａ相電極付近で溶湯わき上がりが起こり、１ａ
ｂ＜Ｉｂｃとなつた時に、ａ相コモンとしたＶ結線ダミ
ーロードを接続し、↑Ａｂｖ−（ｋ−１［Ｉａｂの電流
とダミーロードに流せば電源に対しての逆相電流Ｖｚ＝
０となることを示し、Ｖ結線ダミーロードを用いたこと
により、不平衡負荷の逆相電流、逆相電圧を大幅に改善
できることがわかる。Then, in the above case, the molten metal rises near the a-phase electrode, and 1a
When b<Ibc, connect a V-connected dummy load with the a-phase common, and let the current of ↑Abv-(k-1[Iab and the dummy load flow through the dummy load, and the negative sequence current to the power supply Vz=
0, and it can be seen that by using the V-connected dummy load, the negative sequence current and negative sequence voltage of the unbalanced load can be significantly improved.
なお、土述した実施例にえいては、ダミーロードを２個
用いたが、ダミーロードを一体にして電極を２組有する
水抵抗で構成しても良く、また各相間用として合計３個
のダミーロードを用いても良い。Although two dummy loads were used in the embodiment described above, the dummy loads may be integrated into a water resistor having two sets of electrodes, and a total of three dummy loads may be used between each phase. A dummy load may also be used.
また、開閉器は必要に応じてサイリスタ素子に代えるこ
とができることは言うまでもない。以上説明したように
この発明による不平衡負荷補正装置は、不平衡負荷を補
正するにＶ結線ダミーロードを用いたものであるために
、不平衡負荷によつて生じる逆相電流、逆相電圧を大巾
に改善することができ、これに伴なつて電源に無理を与
えないとともに電源を特殊なものとする必要がないため
に電源装置の寿命を伸ばし、かつ経済的な電源を使用す
ることができる種々の優れた効果を有する。Furthermore, it goes without saying that the switch can be replaced with a thyristor element if necessary. As explained above, since the unbalanced load correction device according to the present invention uses a V-connected dummy load to correct the unbalanced load, it is possible to correct the negative sequence current and negative sequence voltage caused by the unbalanced load. As a result, the life of the power supply device can be extended, and an economical power source can be used since it does not require a special power source and does not put strain on the power source. It has various excellent effects.
第１図は従来の不平衡補正装置を示す回路図、第２図は
この発明による不平衡負荷装置の一実施例を示す回路図
、第３図は各相電流を示すベクトル図、第４図はこの発
明の不平衡負荷補正装置において、１相のみ高インピー
ダンスになつたときの不平衡負荷と逆相電流の関係を示
す回路図、第５図は第４図における電圧、電流のベクト
ル図、第６図は同上不平衡負荷補正装置におけるＶ結線
ダミーロードの負荷電流を示す回路図、第７図は第６図
における負荷電流のベクトル図である。
１：電源、２：電源母線、３：負荷、４，９：Ｒ相開閉
器、５，１０：Ｓ相開閉器、６，１１：Ｔ相開閉器、７
リダミーロード、８：不平衡負荷検出装置、１２：ダミ
ーロードＡｌｌ３，ｌ６，ｌ９：Ｒ相電流、１４，１７
，２０：Ｓ相電流、１５，１８，２１：Ｔ相電流。Fig. 1 is a circuit diagram showing a conventional unbalance correction device, Fig. 2 is a circuit diagram showing an embodiment of an unbalanced load device according to the present invention, Fig. 3 is a vector diagram showing each phase current, and Fig. 4 is a circuit diagram showing the relationship between the unbalanced load and the negative sequence current when only one phase becomes high impedance in the unbalanced load correction device of the present invention, and FIG. 5 is a vector diagram of the voltage and current in FIG. 4. FIG. 6 is a circuit diagram showing the load current of a V-connected dummy load in the unbalanced load correcting device, and FIG. 7 is a vector diagram of the load current in FIG. 6. 1: Power supply, 2: Power bus, 3: Load, 4, 9: R phase switch, 5, 10: S phase switch, 6, 11: T phase switch, 7
Redummy load, 8: Unbalanced load detection device, 12: Dummy load All3, l6, l9: R phase current, 14, 17
, 20: S phase current, 15, 18, 21: T phase current.
Claims (1)
荷をダミーロードを用いて補正する補正装置において、
前記ダミーロードをＶ結線となるように電源母線に接続
することを特徴とする不平衡負荷補正装置。1. In a correction device that uses a dummy load to correct unbalanced loads due to load fluctuations in a three-phase power supply circuit,
An unbalanced load correction device characterized in that the dummy load is connected to a power supply bus in a V-connection manner.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP52081624A JPS593103B2 (en) | 1977-07-07 | 1977-07-07 | Unbalanced load correction device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP52081624A JPS593103B2 (en) | 1977-07-07 | 1977-07-07 | Unbalanced load correction device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5416652A JPS5416652A (en) | 1979-02-07 |
| JPS593103B2 true JPS593103B2 (en) | 1984-01-23 |
Family
ID=13751474
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP52081624A Expired JPS593103B2 (en) | 1977-07-07 | 1977-07-07 | Unbalanced load correction device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS593103B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53105985A (en) * | 1977-02-28 | 1978-09-14 | Nec Corp | Conmplementary-type insulating gate field effect transistor |
| JPS55126464A (en) * | 1979-03-22 | 1980-09-30 | Nec Corp | Ink-drip electrifying method for ink-jet type recording device |
| JPS55111272A (en) * | 1979-02-22 | 1980-08-27 | Nec Corp | Method of charging ink drop in ink jet recorder |
-
1977
- 1977-07-07 JP JP52081624A patent/JPS593103B2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5416652A (en) | 1979-02-07 |
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