JPH1042469A - Power supply system - Google Patents
Power supply systemInfo
- Publication number
- JPH1042469A JPH1042469A JP8195807A JP19580796A JPH1042469A JP H1042469 A JPH1042469 A JP H1042469A JP 8195807 A JP8195807 A JP 8195807A JP 19580796 A JP19580796 A JP 19580796A JP H1042469 A JPH1042469 A JP H1042469A
- Authority
- JP
- Japan
- Prior art keywords
- power factor
- bus
- compensator
- power
- supply system
- 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.)
- Pending
Links
Classifications
-
- Y—GENERAL 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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/30—Reactive power compensation
Landscapes
- Supply And Distribution Of Alternating Current (AREA)
- Motor And Converter Starters (AREA)
- Control Of Electrical Variables (AREA)
- Control Of Ac Motors In General (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は、誘導電動機の始動
時に無効電力を補償し、始動時の電圧降下に起因する電
力系統への影響を軽減したり、補償電流を供給して高調
波を抑制する、インバータ利用の補償装置を備えた給電
システムに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention compensates for reactive power at the time of starting an induction motor, reduces the influence on a power system due to a voltage drop at the time of starting, and suppresses harmonics by supplying a compensation current. A power supply system including a compensator using an inverter.
【0002】[0002]
【従来の技術】大形の誘導電動機を始動する場合、特
に、かご形誘導電動機では力率が悪くなり、変圧器の二
次側母線電圧を低下させ、始動トルクの減少を招くばか
りでなく、他機器に悪影響を及ぼしたりする。この防止
策として、変圧器の%インピーダンスを小さくしたり、
電動機の始動にリアクトル始動やコンドルファ始動を採
用したりしている。2. Description of the Related Art When starting a large-sized induction motor, a squirrel-cage induction motor, in particular, has a poor power factor, lowers the secondary bus voltage of the transformer, and causes a reduction in starting torque. It may adversely affect other devices. To prevent this, you can reduce the% impedance of the transformer,
For example, a reactor start or condorfa start is used to start the motor.
【0003】[0003]
【発明が解決しようとする課題】しかし、このように変
圧器や電動機の始動法を考慮しても、大形電動機の場合
は系統短絡電流が増大する、といった問題が生じる。However, even in consideration of the starting method of the transformer and the electric motor, there is a problem that the short-circuit current of the large electric motor increases.
【0004】そこで本発明は、上記課題を解決し、電動
機始動時の電圧降下に起因する悪影響を極力軽減できる
給電システムを提供することを目的とする。Accordingly, an object of the present invention is to solve the above-mentioned problems and to provide a power supply system capable of minimizing adverse effects caused by a voltage drop at the time of starting a motor.
【0005】また本発明は、母線電流の高調波を十分に
抑制できる給電システムを提供することを目的とする。Another object of the present invention is to provide a power supply system capable of sufficiently suppressing harmonics of a bus current.
【0006】[0006]
【課題を解決するための手段】本発明は、変圧器の二次
側母線にベースロードと、比較的頻繁にオン、オフされ
る誘導電動機とが接続された給電システムにおいて、母
線に力率改善用の無効電力を供給する、インバータを主
体とする補償装置と、母線の電圧及び電流から力率を求
める力率検出部と、この検出部の検出出力に基づいて前
記母線の力率が所望の力率となるように前記補償装置を
制御する力率改善制御部とを備え、少なくとも誘導電動
機の始動時には補償装置が動作状態にあるようにしたこ
とを特徴とする。SUMMARY OF THE INVENTION The present invention relates to a power supply system in which a base load and an induction motor which is turned on and off relatively frequently are connected to a secondary bus of a transformer. A compensator mainly comprising an inverter, a power factor detecting unit for obtaining a power factor from a voltage and a current of the bus, and a power factor of the bus based on a detection output of the detecting unit. A power factor improvement control unit that controls the compensating device so as to obtain a power factor, wherein the compensating device is in an operating state at least when the induction motor is started.
【0007】また本発明は、変圧器の二次側母線にベー
スロードと、比較的頻繁にオン、オフされる誘導電動機
とが接続された給電システムにおいて、母線に力率改善
用の無効電力を供給する、インバータを主体とする補償
装置と、母線の電圧及び電流から力率を求める力率検出
部と、この検出部の検出出力に基づいて前記母線の力率
が所望の力率となるように前記補償装置を制御する力率
改善制御部と、母線電流を検出し、その高調波成分を相
殺する補償電流指令を出す高調波抑制指令部とを備えた
ことを特徴とする。Further, according to the present invention, in a power supply system in which a base load and an induction motor which is turned on and off relatively frequently are connected to a secondary bus of a transformer, reactive power for improving a power factor is supplied to the bus. A compensating device mainly including an inverter, a power factor detecting unit for obtaining a power factor from a voltage and a current of the bus, and a power factor of the bus based on a detection output of the detecting unit. A power factor improvement control unit for controlling the compensating device, and a harmonic suppression command unit for detecting a bus current and issuing a compensation current command for canceling a harmonic component thereof.
【0008】[0008]
【発明の実施の形態】図1に本発明の一実施形態を示
す。図中、1は変圧器、2は一次側遮断器、3は二次側
遮断器、4は前記変圧器1の二次側母線である。この母
線4には、ベースロードとして誘導電動機5Aやその他
の負荷5Bと、比較的頻繁にオン、オフされる誘導電動
機6とを接続し、更にインバータを主体として無効電力
を補償する補償装置7を接続している。補償装置7は、
インバータの発生する無効電力を積極的に活用して、進
みあるいは遅れ位相の無効電力を母線4に供給して力率
改善を図ったり、母線電流の高調波を相殺する補償電流
を発生する機能を備えており、例えば電圧形インバータ
と直流側のコンデンサによって構成している。8〜10
は遮断器、11は電力ヒューズ(PF)、12は真空電
磁接触器(VCS)である。13は前記変圧器1の二次
側に設けた計器用変圧器(PT)、14及び15は母線
4の全体の電流を検出する変流器(CT)、16は前記
PT13とCT14からの電圧、電流信号を受けて母線
4の力率を算出する力率検出部、17はこの力率検出部
16の検出出力を受けて所望の力率(設定値)となるよ
うに前記補償装置7に制御信号を送る力率改善制御部、
18は前記CT15の検出電流から母線4の電流に含ま
れる高調波成分を検出し、それを相殺する補償電流の指
令値を発生するアクティブフィルタ機能ユニットであ
り、このユニット8の指令値を前記補償装置7に与えて
高調波を相殺する補償電流を発生させるようにしてい
る。FIG. 1 shows an embodiment of the present invention. In the figure, 1 is a transformer, 2 is a primary circuit breaker, 3 is a secondary circuit breaker, and 4 is a secondary bus of the transformer 1. The bus 4 is connected with an induction motor 5A or other load 5B as a base load, and an induction motor 6 that is turned on and off relatively frequently, and further provided with a compensator 7 that mainly uses an inverter to compensate for the reactive power. Connected. The compensator 7
The reactive power generated by the inverter is actively utilized to supply the reactive power of the leading or lagging phase to the bus 4 to improve the power factor or to generate a compensation current for canceling the harmonics of the bus current. For example, it is constituted by a voltage source inverter and a capacitor on the DC side. 8-10
Is a circuit breaker, 11 is a power fuse (PF), and 12 is a vacuum electromagnetic contactor (VCS). 13 is an instrumentation transformer (PT) provided on the secondary side of the transformer 1, 14 and 15 are current transformers (CT) for detecting the entire current of the bus 4, and 16 is a voltage from the PT13 and CT14. The power factor detecting unit 17 that receives the current signal and calculates the power factor of the bus 4 receives the detection output of the power factor detecting unit 16 and gives the compensating device 7 a desired power factor (set value). Power factor improvement control unit that sends control signals,
Reference numeral 18 denotes an active filter function unit that detects a harmonic component included in the current of the bus 4 from the detected current of the CT 15 and generates a command value of a compensation current for canceling the harmonic component. It is provided to the device 7 to generate a compensation current that cancels out harmonics.
【0009】次に、動作について述べる。まず、アクテ
ィブフィルタ機能の無い場合について説明する。この場
合は、誘導電動機6を始動する前に遮断器10を投入し
て補償装置7を運転状態とする。補償装置7の運転状態
では、力率を所望の値(例えば、lead0.8、1.
0またはlag0.8など)に設定する。この後、遮断
器9を投入して誘導電動機6の始動を行うと、誘導電動
機6の始動に伴い母線4の力率が著しく悪化する。これ
が力率検出部16によって検出され、力率改善制御部1
7から補償装置7へ力率改善指令が出される。即ち、所
望の力率設定値となるように補償装置7から無効電力が
母線4へ供給される。これにより、力率が即時に改善さ
れ、十分な始動トルクが得られたり、他機器への悪影響
が大幅に軽減される。Next, the operation will be described. First, a case without the active filter function will be described. In this case, the circuit breaker 10 is turned on before the induction motor 6 is started, and the compensator 7 is brought into the operating state. In the operating state of the compensator 7, the power factor is set to a desired value (for example, lead 0.8, 1..
0 or lag 0.8). Thereafter, when the breaker 9 is turned on to start the induction motor 6, the power factor of the bus 4 is significantly deteriorated with the start of the induction motor 6. This is detected by the power factor detection unit 16 and the power factor improvement control unit 1
7 issues a power factor improvement command to the compensating device 7. That is, the reactive power is supplied from the compensator 7 to the bus 4 so as to have a desired power factor set value. As a result, the power factor is immediately improved, sufficient starting torque is obtained, and adverse effects on other devices are greatly reduced.
【0010】誘導電動機6の始動完了後も遮断器10の
投入状態を維持すれば、平常状態でも全体の力率が所望
値となるように制御される。この場合、アクティブフィ
ルタ機能を備えているものであれば、母線電流の高調波
がアクティブフィルタ機能ユニット18によって検出さ
れ、それを相殺する補償電流の指令値が補償装置7へ付
与される。この結果、補償装置7は補償電流を発生し、
これを母線4へ供給する。これにより、母線電流の高調
波が抑制される。If the closed state of the circuit breaker 10 is maintained even after the start of the induction motor 6 is completed, the entire power factor is controlled to a desired value even in a normal state. In this case, if the active filter function is provided, a harmonic of the bus current is detected by the active filter function unit 18, and a compensation current command value for canceling the harmonic is given to the compensator 7. As a result, the compensation device 7 generates a compensation current,
This is supplied to the bus 4. Thereby, harmonics of the bus current are suppressed.
【0011】[0011]
【発明の効果】以上のように本発明によれば、始動時に
力率を悪化させる誘導電動機が接続された変圧器二次側
母線にインバータを主体とする補償装置を接続し、少な
くとも始動時に進み位相の無効電力を供給して力率改善
を図るようにしたので、直入れ始動のような簡易な始動
回路でありながら、短絡容量を増大させることなく大形
誘導電動機の始動が可能となり、変圧器容量の低減が図
れる。しかも、誘導電動機の始動後における力率改善に
も寄与し得る。また、アクティブフィルタ機能を追設す
ることにより、高調波抑制を適確に行うことが可能であ
り、高調波対策にも有効となる。As described above, according to the present invention, a compensator mainly composed of an inverter is connected to a secondary bus of a transformer to which an induction motor for deteriorating a power factor is connected at the time of starting. Since the power factor is improved by supplying the reactive power of the phase, it is possible to start a large induction motor without increasing the short-circuit capacity, even though it is a simple starting circuit such as a direct start. The capacity can be reduced. In addition, it can contribute to the improvement of the power factor after starting the induction motor. Further, by additionally providing the active filter function, it is possible to accurately perform harmonic suppression, which is also effective for harmonic countermeasures.
【図1】本発明の一実施形態を示す単線接続図。FIG. 1 is a single-wire connection diagram showing an embodiment of the present invention.
1…変圧器 2…一次側遮断器 3…二次側遮断器 4…二次側母線 5A,5B…ベースロード 6…誘導電動機 7…インバータを主体とする補償装置 13…PT 14,15…CT 16…力率検出部 17…力率改善制御部 18…アクティブフィルタ機能ユニット DESCRIPTION OF SYMBOLS 1 ... Transformer 2 ... Primary circuit breaker 3 ... Secondary circuit breaker 4 ... Secondary bus 5A, 5B ... Base load 6 ... Induction motor 7 ... Compensation device mainly with an inverter 13 ... PT 14,15 ... CT 16: Power factor detection unit 17: Power factor improvement control unit 18: Active filter function unit
Claims (2)
比較的頻繁にオン、オフされる誘導電動機とが接続され
た給電システムにおいて、母線に力率改善用の無効電力
を供給する、インバータを主体とする補償装置と、母線
の電圧及び電流から力率を求める力率検出部と、この検
出部の検出出力に基づいて前記母線の力率が所望の力率
となるように前記補償装置を制御する力率改善制御部と
を備え、少なくとも誘導電動機の始動時には補償装置が
動作状態にあるようにしたことを特徴とする給電システ
ム。1. A base load on a secondary bus of a transformer,
In a power supply system connected to an induction motor which is turned on and off relatively frequently, a compensator mainly composed of an inverter for supplying reactive power for power factor improvement to a bus, and a power factor based on a voltage and a current of the bus. And a power factor improvement control unit that controls the compensator so that the power factor of the bus becomes a desired power factor based on the detection output of the detection unit. A power supply system, wherein the compensator is in an operating state at the time of starting.
比較的頻繁にオン、オフされる誘導電動機とが接続され
た給電システムにおいて、母線に力率改善用の無効電力
を供給する、インバータを主体とする補償装置と、母線
の電圧及び電流から力率を求める力率検出部と、この検
出部の検出出力に基づいて前記母線の力率が所望の力率
となるように前記補償装置を制御する力率改善制御部
と、母線電流を検出し、その高調波成分を相殺する補償
電流指令を出す高調波抑制指令部とを備えたことを特徴
とする給電システム。2. A base load on a secondary bus of the transformer,
In a power supply system connected to an induction motor which is turned on and off relatively frequently, a compensator mainly composed of an inverter for supplying reactive power for power factor improvement to a bus, and a power factor based on a voltage and a current of the bus. And a power factor improvement control unit that controls the compensator so that the power factor of the bus becomes a desired power factor based on a detection output of the detection unit, and a bus current is detected. A power supply system comprising: a harmonic suppression command unit that issues a compensation current command for canceling the harmonic component.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP8195807A JPH1042469A (en) | 1996-07-25 | 1996-07-25 | Power supply system |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP8195807A JPH1042469A (en) | 1996-07-25 | 1996-07-25 | Power supply system |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH1042469A true JPH1042469A (en) | 1998-02-13 |
Family
ID=16347316
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP8195807A Pending JPH1042469A (en) | 1996-07-25 | 1996-07-25 | Power supply system |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH1042469A (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003502814A (en) * | 1999-06-22 | 2003-01-21 | コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ | X-ray inspection equipment |
CN106058877A (en) * | 2016-06-07 | 2016-10-26 | 李为人 | Intelligent low-voltage reactive power compensation device for medium frequency furnace |
JP2016213985A (en) * | 2015-05-11 | 2016-12-15 | 日立Geニュークリア・エナジー株式会社 | In-plant power supply system for power generation plant |
CN106685267A (en) * | 2017-03-24 | 2017-05-17 | 北京北方箱变电气有限公司 | Startup compensation device of high voltage motor |
-
1996
- 1996-07-25 JP JP8195807A patent/JPH1042469A/en active Pending
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003502814A (en) * | 1999-06-22 | 2003-01-21 | コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ | X-ray inspection equipment |
JP2016213985A (en) * | 2015-05-11 | 2016-12-15 | 日立Geニュークリア・エナジー株式会社 | In-plant power supply system for power generation plant |
CN106058877A (en) * | 2016-06-07 | 2016-10-26 | 李为人 | Intelligent low-voltage reactive power compensation device for medium frequency furnace |
CN106685267A (en) * | 2017-03-24 | 2017-05-17 | 北京北方箱变电气有限公司 | Startup compensation device of high voltage motor |
CN106685267B (en) * | 2017-03-24 | 2024-01-02 | 北京北方永达智能电气有限公司 | High-voltage motor starting compensation equipment |
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Legal Events
Date | Code | Title | Description |
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A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20040427 |