JPH0258762B2

JPH0258762B2 -

Info

Publication number: JPH0258762B2
Application number: JP57036593A
Authority: JP
Inventors: Tsunetoshi Kashiwazaki
Original assignee: Tokyo Shibaura Electric Co Ltd
Current assignee: Toshiba Corp
Priority date: 1982-03-10
Filing date: 1982-03-10
Publication date: 1990-12-10
Also published as: JPS58154217A

Description

[Detailed description of the invention]

〔発明の技術分野〕本発明は制御装置やリレー等に制御用電力を供
給する制御用変圧器に関する。〔発明の技術的背景〕一般にある種の電力用制御装置やリレー等（以
下、これを単にリレーと言う）は、３相電源側の
１線断線事故や２相短絡事故時においても正常に
動作することが要求される。このため、従来は第
１図に示すように例えば３相6600Vを３相Ｖ結線
変圧器で受電して適当な２次電圧に下げ、３相グ
レツツ結線で直流に変換し、得られる制御用電力
をリレーに供給していた。これによれば、３相
6600Vの配電線に１線断線事故や２相短絡事故が
発生したとき、直流出力電圧を喪失させずに単相
全波整流相当の電圧、即ち正常時の2/3の値をリ
レーに供給することができる。一方、動作中のリ
レーが印加電圧の低下により、動作状態を維持出
来なくなり、元の状態へ復帰する電圧（以下、復
帰電圧と称する）の下限値は、リレーに付属回路
等を用いることにより定格（正常時）の約30％と
言われている。従つて、前記回路条件では、正常
時の2/3の電圧が維持されるため、リレーは誤動
作を起こさないで済む。〔背景技術の問題点〕しかしながら、上記従来方式では、整流器やそ
れをサージから保護するためのコンデンサや抵抗
を付属させねばならず、装置が複雑になり、大形
化し、高価になる。しかも、部品数がなくなり、
システムとしての信頼性が低下する等の欠点があ
つた。〔発明の目的〕本発明はコンデンサや抵抗等の付属品を不要と
し、３相電源側の１線断線事故や２相短絡時にお
いてもリレーを正常に動作させるに必要な最低電
圧を確保し得る制御用変圧器を提供することを目
的とする。〔発明の概要〕このため本発明は、鉄心にギヤツプを設けた単
相変圧器２台をＶ結線に接続し、その２次コイル
の巻回数の一方を他方のほぼ半分にして制御用変
圧器を構成したことを特徴とする。〔発明の実施例〕第２図は本発明の一実施例を係る制御用変圧器
（以下、Trと言う）の構成図を示したもので、
ａ、ｂは２台のTrである。この２台のTra、ｂ
における１−１，１−２は１次コイルと２次コイ
ルを同軸的に配置したコイル、２−１，２−２は
ギヤツプ３−１，３−２を設けた鉄心である。そ
の２台のTra，ｂはその１次コイルをＶ結線と
し、その端子Ｕ、Ｖ、Ｗを３相電源Ｐに接続す
る。また、２次コイルもＶ結線とし、その端子を
ｕ、ｖ、ｗとしてwu間にリレー４を接続する。
更に、Traの巻数比に対しTrbの巻数比を２倍と
する。以上の構成で、Tra、Trbの励磁インピーダン
スを各々Zoa、Zob、漏洩インピーダンスをＺと
してTraの２次電圧に換算した等価回路を書け
ば、第３図の如くなる。この図において、Tra、
Trbは理想的な変圧器とし、Traの巻数比を１：
１、Trbの巻数比を１：Ｎとする。１次コイルの
端子間電圧を各々V_UV、V_VW、V_WU、２次コイル
の端子間の電圧を各々V_uv、V_vw、V_wuとする。今、Zoa＝Zobとし、Ｚの1/5になるようにギヤ
ツプ３を調整したとして、１線断線事故、２相短
絡事故時のV_wuの値を求める式を示すと第１表の
ようになる。第１表において、Ｖ結線を構成する
ＵおよびＷ相用単相変圧器の２次コイルが、等価
的に直列接続となつたUW間に所望の電圧を得る
ためには、１次コイルと２次コイルの極性は、Ｕ
およびＷ相用単相変圧器とも同極性でなければな
らない。 [Technical Field of the Invention] The present invention relates to a control transformer that supplies control power to a control device, a relay, etc. [Technical Background of the Invention] Generally, certain types of power control devices, relays, etc. (hereinafter simply referred to as relays) operate normally even in the event of a one-wire disconnection accident or a two-phase short circuit accident on the three-phase power supply side. required to do so. For this reason, in the past, as shown in Figure 1, for example, 3-phase 6600V was received with a 3-phase V-connection transformer, lowered to an appropriate secondary voltage, and converted to DC using a 3-phase Gretz connection, resulting in control power. was being supplied to the relay. According to this, three-phase
When a single wire disconnection or two-phase short circuit occurs on a 6600V distribution line, the voltage equivalent to single-phase full-wave rectification, that is, 2/3 of the normal value, is supplied to the relay without loss of DC output voltage. be able to. On the other hand, the lower limit of the voltage at which an operating relay can no longer maintain its operating state due to a drop in applied voltage and returns to its original state (hereinafter referred to as return voltage) can be determined by using an attached circuit etc. It is said to be about 30% of normal (normal). Therefore, under the above circuit conditions, two-thirds of the normal voltage is maintained, so the relay does not malfunction. [Problems with Background Art] However, in the above-mentioned conventional system, a rectifier and a capacitor and a resistor for protecting the rectifier from surges must be attached, making the device complicated, large-sized, and expensive. Moreover, the number of parts has disappeared,
There were drawbacks such as decreased reliability as a system. [Object of the Invention] The present invention eliminates the need for accessories such as capacitors and resistors, and can ensure the minimum voltage necessary for normal operation of the relay even in the event of a single wire disconnection accident on the 3-phase power supply side or a 2-phase short circuit. The purpose is to provide control transformers. [Summary of the Invention] Therefore, the present invention provides a control transformer in which two single-phase transformers each having a gap in the iron core are connected in a V-connection, and the number of turns of one of the secondary coils is approximately half that of the other. It is characterized by comprising the following. [Embodiment of the Invention] FIG. 2 shows a configuration diagram of a control transformer (hereinafter referred to as Tr) according to an embodiment of the present invention.
a and b are two transistors. These two Tra, b
1-1 and 1-2 are coils in which a primary coil and a secondary coil are arranged coaxially, and 2-1 and 2-2 are iron cores provided with gaps 3-1 and 3-2. The two Tra and b have their primary coils connected to V, and their terminals U, V, and W are connected to a three-phase power supply P. Further, the secondary coil is also V-connected, and its terminals are set as u, v, and w, and a relay 4 is connected between wu and wu.
Furthermore, the turns ratio of Trb is set to be twice that of Tra. With the above configuration, if we write an equivalent circuit in which the excitation impedances of Tra and Trb are Zoa and Zob, and the leakage impedance is Z, and are converted to the secondary voltage of Tra, it will be as shown in FIG. 3. In this figure, Tra,
Trb is an ideal transformer, and the turns ratio of Tra is 1:
1. The turns ratio of Trb is 1:N. The voltages between the terminals of the primary coil are V _UV , V _VW , and V _WU , and the voltages between the terminals of the secondary coil are V _uv , V _vw , and V _wu , respectively. Now, assuming that Zoa = Zob and adjusting the gap 3 so that it becomes 1/5 of Z, the formula for calculating the value of V _wu in the event of a 1-wire disconnection accident or a 2-phase short circuit accident is shown in Table 1. Become. In Table 1, in order to obtain the desired voltage across UW, which is equivalently connected in series, the secondary coil of the U- and W-phase single-phase transformer constituting the V connection must be connected to the primary coil and the secondary coil. The polarity of the next coil is U
and the W-phase single-phase transformer must have the same polarity.

〔Effect of the invention〕

以上のように本発明によれば、従来の場合より
構造が簡単になり、小形、軽量、経済的にして信
頼性が高く、ヒユーズの自然劣化による溶断時に
もリレーの誤動作を防止できるなどシステムの信
頼性向上にも寄与し得る優れた制御用変圧器が得
られる。 As described above, according to the present invention, the structure is simpler than the conventional case, it is small, lightweight, economical, and highly reliable, and it is possible to prevent malfunction of the relay even when the fuse blows due to natural deterioration. An excellent control transformer that can also contribute to improved reliability can be obtained.

[Brief explanation of the drawing]

第１図は制御用電源装置の回路図、第２図は本
発明の一実施例を示す制御用変圧器の概念図、第
３図は本発明の作用を説明するための等価回路図
である。１−１，１−２…コイル、２−１，２−２…鉄
心、３−１，３−２…ギヤツプ、ａ、ｂ…制御用
変圧器。 Fig. 1 is a circuit diagram of a control power supply device, Fig. 2 is a conceptual diagram of a control transformer showing an embodiment of the present invention, and Fig. 3 is an equivalent circuit diagram for explaining the operation of the present invention. . 1-1, 1-2... Coil, 2-1, 2-2... Iron core, 3-1, 3-2... Gap, a, b... Control transformer.

Claims

[Claims]

1 Primary coil and 2
Two single-phase transformers are installed by winding the following coils,
The primary and secondary coils of these two single-phase transformers are connected in a 3-phase V connection, and the two secondary coils have a turns ratio of 1: approximately 0.5, and a single-phase control power source is connected between both terminals. A control transformer characterized in that it is configured to be taken out.