JP2003284353A - Power converter - Google Patents
Power converterInfo
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- JP2003284353A JP2003284353A JP2003029136A JP2003029136A JP2003284353A JP 2003284353 A JP2003284353 A JP 2003284353A JP 2003029136 A JP2003029136 A JP 2003029136A JP 2003029136 A JP2003029136 A JP 2003029136A JP 2003284353 A JP2003284353 A JP 2003284353A
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- converter
- contactor
- current
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- ground fault
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Abstract
Description
【発明の詳細な説明】
【０００１】
【発明の属する技術分野】本発明は、交流を電源として
それを直流に変換する電力変換装置に係り、特に、該装
置の地絡に伴う対応技術に関する。
【０００２】
【従来の技術】従来の交流を電源としてそれを直流に変
換する電力変換装置としては、例えば、特開昭６３−１
８６５０５号公報がある。同公報の電力変換装置は交流
鉄道電気車に特定されたものであり、それは図２に示さ
れる以下のような構成を有する。架線より交流電力を取
り込むパンタグラフ１と変圧器３の１次巻線４とは交流
遮断器２が介在されて接続され、変圧器３の１次巻線４
の他方はレール（接地）に接する車輪１５に接地ブラシ
１３を介して接続される。変圧器３の２次巻線５の一端
は接触器７を介して単相コンバータ５１の交流入力端
（ｕ相）に、２次巻線５の他端は単相コンバータの交流
入力端（ｖ相）に接続される。接触器７の両端には充電
抵抗器６と補助接触器８の直列体が接続される。単相コ
ンバータ５１の直流出力端には、フィルタコンデンサ１
１、３相インバータ５２の直流側が接続され、該インバ
ータの交流側には電動機１２が接続される。ここで、単
相コンバータ５１は、ｕ相においては上アームが半導体
スイッチング素子（以下、素子と略す）２０ｕとフリー
ホイールダイオード２４ｕを逆極性で並列接続した並列
体から構成され、下アームも同様に素子２１ｕとフリー
ホイールダイオード２５ｕから構成され、同相アームは
上下アームの直列体からなっている。また、ｖ相におい
てもｕ相と同様に素子２０ｖ，２１ｖ、及びフリーホイ
ールダイオード２４ｖ，２５ｖから構成される。一方、
３相インバータ５２は、上記コンバータと同様のアーム
構成を有し、ｕ〜相の３相分の素子３０ｕ，３１ｕ，３
０ｖ，３１ｖ，３０ｗ，３１ｗとフリーホイールダイオ
ード３４ｕ，３５ｕ，３４ｖ，３５ｖ，３４ｗ，３５ｗ
から構成される。また、単相コンバータ５１の直流側の
一端（図ではフィルタコンデンサのマイナス側）は、接
地線１４により接地ブラシ１３に接続（接地）され、該
接地線には地絡電流を検出する接地継電器５３が設けら
れる。筺体６０は、いわゆる制御装置内の機器を納める
制御箱であり、同図記載のものでは単相コンバータ５
１、３相インバータ５２、フィルタコンデンサ１１、接
触器７、充電抵抗器６、補助接触器８が筺体６０に収納
される。この筺体６０は電気的に接地ブラシ１３に接続
（接地）される。
【０００３】ここで、接触器７、充電抵抗器６及び補助
接触器８の機能は、フィルタコンデンサ１１が充電され
ていない状態から接触器７を投入すると、過大な充電電
流が変圧器３から単相コンバータ５１に流れ込むことを
防止することにある。そこで、フィルタコンデンサ１１
を充電するときには、まず補助接触器８を投入して充電
抵抗器６により制限された充電電流でフィルタコンデン
サ１１を充電し、ある程度の電荷が充電されてから接触
器７を投入する。また、フィルタコンデンサ１１のマイ
ナス側と接地ブラシ５３間を接続する接続線１４に設け
られる接地継電器５３の機能は、フィルタコンデンサ１
１のプラス側、又は単相コンバータ５１、又は３相イン
バータ等が地絡して接地ブラシ１３と同一の電位に電気
的に接続された場合に、地絡電流を検知して交流遮断器
２を開放して地絡電流が流れ続けることを防止するもの
である。
【０００４】
【発明が解決しようとする課題】図２の電力変換装置で
地絡事故が発生した場合を考える。前述のようにフィル
タコンデンサ１１のプラス側、又は単相コンバータ５
１、又は３相インバータ５２が地絡すると、接地継電器
５３が地絡電流を検出して交流遮断器２を開放すると同
時に、接触器７及び補助交流接触器８を開放する。その
後、運転を再開するために交流遮断器２を投入するが、
このときに地絡箇所がまだ取り除かれておらず、特にそ
の地絡箇所が２次巻線５と接触器７との間に発生してい
た場合には、接触器７、補助接触器８が開放されていて
も交流遮断器２の投入と同時に再度地絡が図２の矢印で
示した経路（筺体６０−接地線１４−フリーホイールダ
イオード２３ｖ−２次巻線５）で発生する。このときの
変圧器３の１次巻線には、２次巻線側の地絡による電流
と、交流遮断器２を投入する時の電源位相とのタイミン
グによっては大きな励磁突入電流も流れることになり、
変圧器のコイルに機械的耐量を超えた大きな電磁力が働
き、変圧器が破損するという課題があった。一般的に、
変圧器に電源を投入するときに１次巻線に励磁突入電流
が流れ、それは電源投入時に最も大きく時間と共に減少
する。励磁突入電流の大きさは、電源電圧、電源位相、
鉄心の残留磁気等により左右され、同じ電源電圧であれ
ば、電源位相０度，残留磁気最大の時に最も大きく、例
えば、１次巻線定格２０ｋＶ，８０Ａ，２次巻線定格９
００Ｖ，７５０Ａ×２の鉄道車両用変圧器の励磁突入電
流は、１次電圧２３ｋＶのときに１次巻線に最大５５０
Ａが流れる。したがって、交流遮断器２の投入時に地絡
電流と突入電流が重なる電流が変圧器に流れると、定格
電流をはるかに越え、このような電流が流れても短時間
であれば、破壊しないだけの電気的、機械的耐量を有す
るよう設計する必要があり、特に電気車ではそれに伴う
重量の増加が問題となる。
【０００５】そこで、本発明の課題は、電力変換装置の
如何なる場所で地絡事故が発生してもその地絡による電
流を確実に遮断すると共に、地絡事故が発生して交流遮
断器が開放した後に、接地箇所が取り除かれないままに
再度交流遮断器が投入されたとしても、変圧器に励磁突
入電流と地絡電流が重なり合って流れる過大電流を防止
することにある。
【０００６】
【課題を解決するための手段】上記課題を解決するため
に、半導体スイッチング素子にフリーホイールダイオー
ドが逆極性で並列接続された並列体を複数個直列接続し
た直列体を２組有して交流を直流に変換する単相コンバ
ータと、単相交流電源をコンバータの交流側両端に接続
する第１と第２の接触器と、コンバータの直流側端子間
に接続されたフィルタコンデンサと、少なくとも第１，
第２の接触器とコンバータ及びフィルタコンデンサが収
納された筺体と、コンバータの直流側の一端及び筺体を
接地線で接地する手段と、第２の接触器に並列接続され
る抵抗器と、コンバータの直流側の一端から接地への電
流を検出する接地継電器とを備え、コンデンサの交流電
源からの充電は第１の接触器を投入後所定時間経過した
後第２の接触器を投入する投入シーケンスとし、接地継
電器の動作時は該継電器の出力に応動して第１と第２の
接触器をほぼ同時に遮断する遮断シーケンスとする。
【０００７】これにより、本発明は、前述の地絡事故と
同様に２次巻線５と接触器７との間で地絡が発生したと
しても、接地継電器からの信号により少なくとも第１の
接触器が開放されるので、図２で示した経路で流れる地
絡電流を遮断できる。また、接地箇所が取り除かれない
ままで交流遮断器２が再投入された場合においても、第
１と第２の接触器により変圧器３の２次巻線５は開放さ
れているため、変圧器には励磁突入電流しか流れない。
その後、第１の接触器が投入された時点で地絡電流が流
れ２次巻線は短絡された状態になるが、このときには励
磁突入電流は減衰して消滅しているので、励磁突入電流
と短絡電流が同時に流れることを防止できる。
【０００８】
【発明の実施の形態】以下、本発明の実施形態を図面を
用いて説明する。図１は、本発明に基づく鉄道電気車の
電力変換装置に応用した一実施形態を示す。なお、図１
の基本構成は図２と同じで同一符号で示しており、その
詳細な説明は前述しているので省略する。図２と構成的
に異なるところは、変圧器３の２次巻線５と単相コンバ
ータ５１との接続部分と、接地線１４にスイッチを設け
たことである。変圧器３の２次巻線５の両端と単相コン
バータ５１の交流側両端子が第１の接触器９と第２の接
触器７を介してそれぞれ接続される。第２の接触器７の
両端には充電抵抗器６が並列接続される。また、フィル
タコンデンサ１１のマイナス側と接地ブラシ１３は、ス
イッチ５４を介在させて接続線１４で接続される。この
スイッチ５４は電力変換装置の絶縁試験用に設けられる
もので、試験時には開放し、定常動作時には投入されて
いる。
【０００９】次に、上記電力変換装置の構成において本
発明の課題を解決させるための交流遮断器２と第１の接
触器と第２の接触器相互間における開閉動作機能につい
て説明する。
〈初期充電モード〉電動機１２に３相インバータ５２よ
り可変周波数可変電圧の交流を給電し、所定のトルクを
発生させて起動させるために、通常、フィルタコンデン
サ１１の直流電圧が所定値に達するまで待機する。そこ
で、フィルタコンデンサ１１を初期充電する場合には次
のシーケンスで行う。先ず、交流遮断器２を投入し、続
いて第１の接触器９を投入する。するとフィルタコンデ
ンサ１１には、２次巻線５の電圧が充電抵抗器６、フリ
ーホイールダイオード２４ｕ，２３ｖを介して印加され
充電電流が流れる。そして充電が完了した後第２の接触
器７を投入する。
〈地絡、運転再開モード〉地絡の仮定として、従来技術
では対応できなかった２次巻線５と第２の接触器７との
間で地絡事故が発生した場合とする。この場合の地絡経
路は、筺体６０−接地線１４−フリーホイールダイオー
ド２３ｖ−第１の接触器９−２次巻線５で地絡電流が流
れる。この時、接地継電器５３が地絡電流を検出し、こ
の検出に応動して交流遮断器２を開放すると同時に、第
１及び第２の接触器９，７を開放する（地絡電流を遮断
する意味では必ずしもこのとき第２の接触器を開放しな
くともよい）。これにより、この経路の地絡電流は遮断
されることになる。
【００１０】その後、地絡原因不明のままで上記地絡箇
所がまだ取り除かれていない状態で運転を再開する場合
がある。その時にも先ず交流遮断器２が投入される。こ
の時点では、未だ第１と第２の接触器により変圧器３の
２次巻線５は投入されておらず、開放状態を維持する。
それにより変圧器には１次巻線に励磁突入電流しか流れ
ない。その後（所定時間後）、第１の接触器９を投入す
る。この時点で再度同じ経路で地絡電流が流れ、２次巻
線は短絡された状態になるが、このときには励磁突入電
流は減衰して消滅しているので、励磁突入電流と短絡電
流が同時に流れることはない。これにより、例え上記条
件の最悪箇所での地絡が発生し、これを無視して再運転
の動作が実行されたとしても、地絡に伴う変圧器での過
大電流の発生を防止することができる。なお、地絡事故
が単相コンバータ５１や３相インバータ５２側で発生し
ている場合は、第１の接触器９を投入した時点で該当部
にかかる電圧は変圧器２次巻線の電圧が充電抵抗器６を
介したものとなるので、上記地絡条件での地絡電流は小
さいものとなる。したがって、接地箇所を取り除かずに
再運転を動作させた場合、接地継電器より地絡電流の大
きさにより接地箇所を見分けることができる。
【００１１】以上、本実施形態における交流遮断器２、
第１及び第２の接触器９，７の投入、遮断時のシーケン
スを纏めると、次のようになる。
投入順序：交流遮断器２−第１の接触器９−第２の接触
器７（９より所定時間遅らせる）。
遮断順序（地絡時）：交流遮断器２、第１及び第２の接
触器９，７共にほぼ同時に動作させる。
【００１２】次に、本発明の他の実施形態を図３より説
明する。図１と異なるところは、単相コンバータ５１を
３レベルのコンバータとしたことである。この単相コン
バータ５１は、ｕ相分として、素子２０ｕ〜２３ｕ、フ
リーホイールダイオード２４ｕ〜２７ｕ、及びクランプ
ダイオード２８ｕ，２９ｕから構成され、ｖ相分とし
て、素子２０ｖ〜２３ｖ、フリーホイールダイオード２
４ｖ〜２７ｖ、及びクランプダイオード２８ｖ，２９ｖ
から構成される。２直列に接続されているクランプダイ
オード２８ｕと２９ｕ、及び２８ｖと２９ｖの接続点
は、２直列に接続されているフィルタコンデンサ１１ｐ
と１１ｎの接続点にそれぞれ接続されて中性点を構成し
ている。そして、この３レベルのコンバータは、各相の
４直列に接続された素子のスイッチングの仕方により、
フィルタコンデンサ１１ｐのプラス側、中性点、フィル
タコンデンサの１１ｎのマイナス側の３つの電位を選択
して出力するものである。
【００１３】接地構造としては、中性点を接地ブラシ１
３の電位に接続している。この例においては、２次巻線
５と第１の接触器７の間が地絡すると、地絡電流はフィ
ルタコンデンサ１１ｎを経由して流れることになるが、
従来例で問題となる地絡事故後の交流遮断器２の再投入
時には、先の地絡事故の時点でフィルタコンデンサ１１
ｎの電荷は全て放電してしまっており、再度の地絡発生
時の地絡電流の第１波は２次巻線を短絡したものと同等
の電流が流れるため、本実施形態により励磁突入電流
と、地絡電流が重なり合うことを防ぐことができる。な
お、同図実施形態での接地構造として中性点を接地する
のが通常であるが、場合によってはフィルタコンデンサ
のマイナス側が接地されることもある。しかし、接地構
造が変わっても本発明による効果は何ら変わることはな
い。
【００１４】
【発明の効果】本発明によれば、地絡事故が発生して交
流遮断器が開放した後に、接地箇所が取り除かれないま
まに再度交流接触器を投入しても、変圧器に励磁突入電
流と変圧器の短絡電流が重なり合って流れ、変圧器のコ
イルに過大な電磁力が働いて変圧器が破壊に至ることを
防ぐことができる。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power converter for converting an alternating current into a direct current by using an alternating current as a power supply, and more particularly to a technology for dealing with a ground fault of the device. 2. Description of the Related Art A conventional power conversion device which uses an alternating current as a power source and converts it into a direct current is disclosed in, for example, JP-A-63-1.
No. 86505. The power converter disclosed in the publication is specified for an AC railway electric vehicle, and has the following configuration shown in FIG. The pantograph 1 for taking in AC power from the overhead wire and the primary winding 4 of the transformer 3 are connected with an AC circuit breaker 2 interposed therebetween, and the primary winding 4 of the transformer 3 is provided.
The other is connected via a ground brush 13 to a wheel 15 which is in contact with a rail (ground). One end of the secondary winding 5 of the transformer 3 is connected to the AC input terminal (u phase) of the single-phase converter 51 via the contactor 7, and the other end of the secondary winding 5 is connected to the AC input terminal (v Phase). A series body of the charging resistor 6 and the auxiliary contactor 8 is connected to both ends of the contactor 7. The DC output terminal of the single-phase converter 51 includes a filter capacitor 1
The DC side of the one- and three-phase inverter 52 is connected, and the motor 12 is connected to the AC side of the inverter. Here, the single-phase converter 51 has, in the u-phase, an upper arm composed of a parallel body in which a semiconductor switching element (hereinafter abbreviated as an element) 20u and a freewheel diode 24u are connected in parallel with opposite polarities. The in-phase arm is composed of an element 21u and a freewheel diode 25u. The v-phase also includes the elements 20v and 21v and the freewheel diodes 24v and 25v as in the u-phase. on the other hand,
The three-phase inverter 52 has an arm configuration similar to that of the above-described converter, and includes elements 30u, 31u, 3
0v, 31v, 30w, 31w and freewheel diodes 34u, 35u, 34v, 35v, 34w, 35w
Consists of One end of the single-phase converter 51 on the DC side (the negative side of the filter capacitor in the figure) is connected (grounded) to the grounding brush 13 via the grounding wire 14, and the grounding wire is connected to a grounding relay 53 for detecting a ground fault current. Is provided. The housing 60 is a control box for housing equipment in a so-called control device.
The one- and three-phase inverters 52, the filter capacitor 11, the contactor 7, the charging resistor 6, and the auxiliary contactor 8 are housed in a housing 60. The housing 60 is electrically connected (grounded) to the ground brush 13. The function of the contactor 7, the charging resistor 6, and the auxiliary contactor 8 is such that if the contactor 7 is turned on while the filter capacitor 11 is not charged, an excessive charging current is simply output from the transformer 3. The purpose is to prevent flow into the phase converter 51. Therefore, the filter capacitor 11
Is charged, first, the auxiliary contactor 8 is turned on, the filter capacitor 11 is charged with the charging current limited by the charging resistor 6, and the contactor 7 is turned on after a certain amount of charge is charged. The function of the grounding relay 53 provided on the connection line 14 connecting the negative side of the filter capacitor 11 and the grounding brush 53 is as follows.
1, when the single-phase converter 51 or the three-phase inverter or the like is grounded and is electrically connected to the same potential as the ground brush 13, the ground fault current is detected and the AC circuit breaker 2 is turned on. It is opened to prevent a ground fault current from continuing to flow. [0004] Consider a case where a ground fault has occurred in the power converter of FIG. As described above, the plus side of the filter capacitor 11 or the single-phase converter 5
When the one or three-phase inverter 52 is grounded, the grounding relay 53 detects the ground fault current and opens the AC circuit breaker 2, and at the same time, opens the contactor 7 and the auxiliary AC contactor 8. After that, the AC circuit breaker 2 is turned on to restart the operation.
At this time, if the ground fault has not yet been removed, and particularly if the ground fault has occurred between the secondary winding 5 and the contactor 7, the contactor 7 and the auxiliary contactor 8 are not used. Even when the AC circuit breaker 2 is open, a ground fault occurs again along the path (housing 60-ground line 14-freewheel diode 23v-secondary winding 5) indicated by the arrow in FIG. At this time, a large exciting rush current also flows through the primary winding of the transformer 3 depending on the timing of the current due to the ground fault on the secondary winding side and the power supply phase when the AC circuit breaker 2 is turned on. Become
There has been a problem that a large electromagnetic force exceeding the mechanical strength acts on the coil of the transformer, and the transformer is damaged. Typically,
When power is applied to the transformer, an exciting inrush current flows through the primary winding, and the power inrush is greatest and decreases with time. The magnitude of the inrush current depends on the power supply voltage, power supply phase,
If the power supply voltage is the same and the power supply voltage is the same, it is the largest when the power supply phase is 0 degree and the remanence is maximum. For example, the primary winding rating is 20 kV, 80 A, the secondary winding rating is 9
The excitation inrush current of the transformer for railway vehicles of 00V, 750A × 2 is a maximum of 550 in the primary winding when the primary voltage is 23 kV.
A flows. Therefore, if a current in which the ground fault current and the inrush current overlap with each other flows into the transformer when the AC circuit breaker 2 is turned on, the rated current will be far exceeded. It is necessary to be designed to have electrical and mechanical durability, and particularly in an electric vehicle, the increase in weight associated therewith becomes a problem. [0005] Therefore, an object of the present invention is to reliably cut off the current due to a ground fault even if a ground fault occurs in any place of the power converter, and to open the AC circuit breaker due to the occurrence of the ground fault. Then, even if the AC circuit breaker is turned on again without removing the grounding point, an excessive current that flows due to the overlapping of the inrush current and the ground fault current in the transformer is prevented. In order to solve the above-mentioned problems, a semiconductor switching element has two sets of series bodies in which a plurality of parallel bodies in which freewheel diodes are connected in parallel with opposite polarities are connected in series. A single-phase converter for converting AC to DC, first and second contactors for connecting a single-phase AC power supply to both ends of the converter on the AC side, and a filter capacitor connected between the DC side terminals of the converter. First
A housing accommodating the second contactor, the converter and the filter capacitor; a means for grounding one end on the DC side of the converter and the housing with a ground line; a resistor connected in parallel to the second contactor; And a grounding relay for detecting a current from one end on the DC side to the ground. Charging of the capacitor from the AC power supply is a closing sequence in which the second contactor is turned on after a predetermined time has elapsed after the first contactor was turned on. During the operation of the grounding relay, a shut-down sequence is adopted in which the first and second contactors are shut off almost simultaneously in response to the output of the relay. As a result, the present invention provides that even if a ground fault occurs between the secondary winding 5 and the contactor 7 in the same manner as in the above-described ground fault, at least the first contact is caused by a signal from the ground relay. Since the device is opened, the ground fault current flowing through the path shown in FIG. 2 can be cut off. Further, even when the AC circuit breaker 2 is turned on again without removing the grounding point, the secondary winding 5 of the transformer 3 is opened by the first and second contactors. , Only the inrush current flows.
Thereafter, when the first contactor is turned on, a ground fault current flows and the secondary winding is short-circuited. At this time, the exciting inrush current is attenuated and disappears. Simultaneous short circuit current can be prevented. [0008] Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment applied to a power converter of a railway electric vehicle according to the present invention. FIG.
2 are the same as those shown in FIG. 2 and are indicated by the same reference numerals. The configuration differs from that of FIG. 2 in that a switch is provided on the connection between the secondary winding 5 of the transformer 3 and the single-phase converter 51 and on the ground line 14. Both ends of the secondary winding 5 of the transformer 3 and both terminals on the AC side of the single-phase converter 51 are connected via a first contactor 9 and a second contactor 7, respectively. The charging resistor 6 is connected in parallel to both ends of the second contactor 7. The negative side of the filter capacitor 11 and the ground brush 13 are connected by a connection line 14 with a switch 54 interposed. The switch 54 is provided for an insulation test of the power converter, and is open at the time of the test and is turned on at the time of a normal operation. Next, a description will be given of an open / close operation function between the AC circuit breaker 2, the first contactor, and the second contactor for solving the problem of the present invention in the configuration of the power converter. <Initial charge mode> Normally, the motor 12 waits until the DC voltage of the filter capacitor 11 reaches a predetermined value in order to supply the motor 12 with an AC having a variable frequency and a variable voltage from the three-phase inverter 52 to generate and start a predetermined torque. I do. Therefore, the following sequence is performed when the filter capacitor 11 is initially charged. First, the AC breaker 2 is turned on, and then the first contactor 9 is turned on. Then, the voltage of the secondary winding 5 is applied to the filter capacitor 11 via the charging resistor 6 and the freewheel diodes 24u and 23v, and a charging current flows. After charging is completed, the second contactor 7 is turned on. <Ground fault, operation restart mode> As a hypothesis of a ground fault, it is assumed that a ground fault occurs between the secondary winding 5 and the second contactor 7, which cannot be handled by the conventional technology. In the ground fault path in this case, a ground fault current flows through the housing 60, the ground wire 14, the freewheel diode 23v, the first contactor 9 and the secondary winding 5. At this time, the grounding relay 53 detects the ground fault current, and in response to this detection, opens the AC circuit breaker 2 and, at the same time, opens the first and second contactors 9 and 7 (cuts off the ground fault current). In a sense, it is not always necessary to open the second contactor at this time). As a result, the ground fault current in this path is cut off. Thereafter, the operation may be restarted in a state where the ground fault location has not been removed yet with the ground fault cause unknown. At that time, the AC circuit breaker 2 is first turned on. At this point, the secondary winding 5 of the transformer 3 has not yet been turned on by the first and second contactors, and is kept open.
As a result, only an inrush current flows through the primary winding of the transformer. Thereafter (after a predetermined time), the first contactor 9 is turned on. At this time, the ground fault current flows again along the same path, and the secondary winding is short-circuited. At this time, the exciting rush current is attenuated and disappears, so the exciting rush current and the short-circuit current flow simultaneously. Never. As a result, even if a ground fault occurs at the worst point under the above conditions and the restart operation is performed ignoring this, it is possible to prevent the occurrence of excessive current in the transformer due to the ground fault. it can. If a ground fault has occurred on the side of the single-phase converter 51 or the three-phase inverter 52, the voltage applied to the corresponding part when the first contactor 9 is turned on is the voltage of the secondary winding of the transformer. Since the current flows through the charging resistor 6, the ground fault current under the ground fault condition becomes small. Therefore, when the restart operation is performed without removing the grounding portion, the grounding portion can be distinguished from the grounding relay by the magnitude of the ground fault current. As described above, the AC circuit breaker 2 in the present embodiment,
The sequence at the time of turning on and off the first and second contactors 9 and 7 is summarized as follows. Order of application: AC circuit breaker 2-first contactor 9-second contactor 7 (delayed by a predetermined time from 9). Interruption order (at the time of ground fault): The AC circuit breaker 2 and the first and second contactors 9 and 7 are operated almost simultaneously. Next, another embodiment of the present invention will be described with reference to FIG. The difference from FIG. 1 is that the single-phase converter 51 is a three-level converter. This single-phase converter 51 is composed of elements 20u to 23u, freewheel diodes 24u to 27u, and clamp diodes 28u and 29u for u phase, and elements 20v to 23v and freewheel diode 2 for v phase.
4v to 27v, and clamp diodes 28v and 29v
Consists of The connection point between the clamp diodes 28u and 29u and 28v and 29v connected in series is connected to the filter capacitor 11p connected in series.
And 11n to form a neutral point. This three-level converter is based on the switching method of the elements connected in series in each phase.
The three potentials on the plus side of the filter capacitor 11p, the neutral point, and the minus side of the filter capacitor 11n are selected and output. As the grounding structure, a neutral point is set to the grounding brush 1
3 potential. In this example, when a ground fault occurs between the secondary winding 5 and the first contactor 7, a ground fault current flows through the filter capacitor 11n.
When the AC circuit breaker 2 is turned on again after a ground fault, which is a problem in the conventional example, the filter capacitor 11
n has been discharged, and the first wave of the ground fault current at the time of the occurrence of the ground fault again flows the same current as that obtained by short-circuiting the secondary winding. Thus, it is possible to prevent the ground fault current from overlapping. Although the neutral point is generally grounded as the grounding structure in the embodiment of the figure, the negative side of the filter capacitor may be grounded in some cases. However, the effect of the present invention does not change even if the grounding structure changes. According to the present invention, after the ground fault has occurred and the AC circuit breaker has been opened, even if the AC contactor is turned on again without removing the grounding portion, the AC transformer is still connected to the transformer. The exciting inrush current and the short-circuit current of the transformer overlap and flow, and it is possible to prevent the transformer from being broken due to excessive electromagnetic force acting on the coil of the transformer.
【図面の簡単な説明】
【図１】本発明の一実施形態を示す交流鉄道車両の電力
変換装置の構成図。
【図２】従来の交流鉄道車両の電力変換装置の構成図。
【図３】本発明の他の実施形態を示す交流鉄道車両の電
力変換装置の構成図。
【符号の説明】
１…パンタグラフ、２…交流遮断器、３…変圧器、４…
１次巻線、５…２次巻線、６…充電抵抗器、７…第２の
接触器、９…第１の接触器、１１…フィルタコンデン
サ、１２…電動機、１３…接地ブラシ、１４…接地線、
１５…車輪、２０ｕ，２０ｖ，２１ｕ，２１ｖ…スイッ
チング素子、２４ｕ，２５ｕ，２２ｖ，２３ｖ…フリー
ホイールダイオード、５１…単相コンバータ、５２…３
相インバータ、５３…接地継電器、５４…スイッチ、６
０…筺体BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram of a power conversion device for an AC railway vehicle according to an embodiment of the present invention. FIG. 2 is a configuration diagram of a conventional power conversion device for an AC railway vehicle. FIG. 3 is a configuration diagram of a power conversion device for an AC railway vehicle according to another embodiment of the present invention. [Description of Signs] 1 ... Pantograph, 2 ... AC circuit breaker, 3 ... Transformer, 4 ...
Primary winding, 5 Secondary winding, 6 Charge resistor, 7 Second contactor, 9 First contactor, 11 Filter capacitor, 12 Motor, 13 Ground brush, 14 Ground wire,
15 ... wheels, 20u, 20v, 21u, 21v ... switching elements, 24u, 25u, 22v, 23v ... freewheel diodes, 51 ... single-phase converters, 52 ... 3
Phase inverter, 53: ground relay, 54: switch, 6
0 ... Housing
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） Ｈ０２Ｍ 7/12 Ｈ０２Ｍ 7/12 Ｎ (72)発明者 寺澤 清 茨城県ひたちなか市市毛1070番地 株式会 社日立製作所水戸工場内 Ｆターム(参考） 5G004 AA05 AB02 BA01 DA01 DC06 5G043 AA04 AC02 BA01 BA07 BC01 5H006 AA04 BB05 CA01 CA12 CA13 CB01 CB08 CC01 CC08 DA04 DB01 DC02 FA02 GA02 5H007 AA05 AA06 AA17 BB06 CA01 CB04 CB05 CC12 CC23 DA06 DC02 FA12 FA19 GA03 GA05 GA08 ──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. 7 Identification symbol FI Theme coat ゛ (Reference) H02M 7/12 H02M 7/12 N (72) Inventor Kiyoshi Terasawa 1070 Ma, Hitachinaka-shi, Ibaraki Co., Ltd. F term in the Mito Plant of Hitachi, Ltd. (reference) FA19 GA03 GA05 GA08
Claims (1)
ダイオードが逆極性で並列接続された並列体を複数個直
列接続した直列体を２組有して交流を直流に変換する単
相コンバータと、単相交流電源を前記コンバータの交流
側両端に接続する第１と第２の接触器と、前記コンバー
タの直流側端子間に接続されたフィルタコンデンサと、
少なくとも前記第１，第２の接触器と前記コンバータ及
び前記フィルタコンデンサが収納された筺体と、前記コ
ンバータの直流側の一端及び前記筺体を接地線で接地す
る手段と、前記第２の接触器に並列接続される抵抗器
と、前記コンバータの直流側の一端から接地への電流を
検出する接地継電器とを備え、前記コンデンサの前記交
流電源からの充電は前記第１の接触器を投入後所定時間
経過した後前記第２の接触器を投入する投入シーケンス
とし、前記接地継電器の動作時は該継電器の出力に応動
して前記第１と第２の接触器をほぼ同時に遮断する遮断
シーケンスとしたことを特徴とする電力変換装置。Claims: 1. A single-phase converter for converting an alternating current into a direct current, comprising two sets of serial units in which a plurality of parallel units in which freewheel diodes are connected in parallel with opposite polarities to a semiconductor switching element are connected in series. A converter, first and second contactors for connecting a single-phase AC power supply to both ends of the AC side of the converter, and a filter capacitor connected between the DC side terminals of the converter;
A housing housing at least the first and second contactors, the converter and the filter capacitor, a means for grounding one end on the DC side of the converter and the housing with a ground wire, and a second contactor. A resistor connected in parallel, and a grounding relay for detecting a current from one end on the DC side of the converter to ground, and charging the capacitor from the AC power source for a predetermined time after turning on the first contactor After the lapse of time, the second contactor is turned on, and when the grounding relay is operated, the first and second contactors are turned off almost simultaneously in response to the output of the relay. A power converter characterized by the above-mentioned.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2003029136A JP3843430B2 (en) | 2003-02-06 | 2003-02-06 | Power converter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2003029136A JP3843430B2 (en) | 2003-02-06 | 2003-02-06 | Power converter |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2950098A Division JP3455797B2 (en) | 1998-02-12 | 1998-02-12 | Power converter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2003284353A true JP2003284353A (en) | 2003-10-03 |
| JP3843430B2 JP3843430B2 (en) | 2006-11-08 |
Family
ID=29244407
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2003029136A Expired - Lifetime JP3843430B2 (en) | 2003-02-06 | 2003-02-06 | Power converter |
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| Country | Link |
|---|---|
| JP (1) | JP3843430B2 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010273455A (en) * | 2009-05-21 | 2010-12-02 | Toshiba Corp | Device for control of electric vehicle |
| JP2011166968A (en) * | 2010-02-10 | 2011-08-25 | Toshiba Corp | Measure against inductive interference in vehicular power converter |
| JP2014135900A (en) * | 2014-04-28 | 2014-07-24 | Toshiba Corp | Electric-vehicle control device |
| CN107154743A (en) * | 2017-03-31 | 2017-09-12 | 深圳晶福源科技股份有限公司 | A kind of Switching Power Supply of controllable two grades of voltage switchings output |
| US9812982B2 (en) | 2014-10-30 | 2017-11-07 | Abb Schweiz Ag | Method in, apparatus for, and interface arrangement between an alternating current power system and a direct current power system |
| WO2024009428A1 (en) * | 2022-07-06 | 2024-01-11 | 三菱電機株式会社 | Short circuit determination device, electronic apparatus, and short circuit determination method |
-
2003
- 2003-02-06 JP JP2003029136A patent/JP3843430B2/en not_active Expired - Lifetime
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010273455A (en) * | 2009-05-21 | 2010-12-02 | Toshiba Corp | Device for control of electric vehicle |
| JP2011166968A (en) * | 2010-02-10 | 2011-08-25 | Toshiba Corp | Measure against inductive interference in vehicular power converter |
| JP2014135900A (en) * | 2014-04-28 | 2014-07-24 | Toshiba Corp | Electric-vehicle control device |
| US9812982B2 (en) | 2014-10-30 | 2017-11-07 | Abb Schweiz Ag | Method in, apparatus for, and interface arrangement between an alternating current power system and a direct current power system |
| CN107154743A (en) * | 2017-03-31 | 2017-09-12 | 深圳晶福源科技股份有限公司 | A kind of Switching Power Supply of controllable two grades of voltage switchings output |
| CN107154743B (en) * | 2017-03-31 | 2019-06-21 | 深圳晶福源科技股份有限公司 | A kind of Switching Power Supply of controllable two grades of voltages switching output |
| WO2024009428A1 (en) * | 2022-07-06 | 2024-01-11 | 三菱電機株式会社 | Short circuit determination device, electronic apparatus, and short circuit determination method |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3843430B2 (en) | 2006-11-08 |
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