【０００１】
【発明の属する技術分野】
本発明は鉄道車両に搭載される強制風冷式電力変換装置に関する。
【０００２】
【従来の技術】
鉄道車両に搭載された半導体素子の冷却を電動送風機による強制通風により冷却する電力変換装置では、当該変換装置筐体の外表面に入風口と排風口とが設けられ、これらが両端部となるよう冷却風洞が装置内部に形成され、冷却風洞内には通風を行う為の電動送風機と半導体素子冷却ユニットの放熱部等の被冷却体が収納される構成となっている。
【０００３】
通常、空気温度の上昇した排風が再び入風口から冷却風洞内に入り込む（一般に冷却風のショートサーキットと呼ばれる）ことを防ぐために、入風口と排風口とは極力離して設置するように設計され、ショートサーキットを起こしにくくなるように構成されている。
【０００４】
また、入風口、排風口での圧力損失を低減し、冷却風が効率良く冷却風洞に入り込み、排出されるように構成することで、電動送風機が大形化するのを防止し、また電動送風機から発生する騒音を抑えている。
【０００５】
次に、鉄道車両の屋根上に設置される従来の電力変換装置を図８及び図９を用いて具体的に説明する。
図８は、従来の電力変換装置が鉄道車両屋根上に取り付けられた平面図、図９は図８の電力変換装置の断面図である。
【０００６】
電力変換装置１は鉄道車両屋根２上に設置されており、変換装置筐体の一方の垂直な外表面に入風口３が、これと反対側の垂直な外表面に排風口４が設置され、さらに入風口３と排風口４とが両端面となるよう電力変換装置１の内部に冷却風洞５が形成されている。
【０００７】
冷却風洞５内には、電動送風機６及び被冷却体が収納されている。ここで被冷却体とは半導体素子冷却ユニットの放熱部、トランス、リアクトル等の巻物のように外気に熱放散する必要のある発熱機器をさす。このような被冷却体は電動送風機６により入風口３より冷却風洞５内に取り込まれた外気の強制通風により冷却される。この従来例では、半導体素子冷却ユニット７の放熱部８が被冷却体であり、冷却風洞５を変換装置筐体内の下方側に取付け、放熱部８が下方となるよう半導体素子冷却ユニット７を電力変換装置１の筐体内に収納している。
【０００８】
ここで、鉄道車両屋根上に設置の電力変換装置１では、変換装置筐体上方からのアクセスとなる為、半導体素子冷却ユニット７の放熱部８を下方、電気部品実装部９を上方側となるよう配置し、装置筐体上方から容易に電気部品実装部９へのアクセスが可能となるように構成されている。
このように冷却風洞５が変換装置筐体内の下方側に構成した場合、入風口３及び排風口４は必然的に変換装置筐体の比較的下方側に設置されることが多い。
【０００９】
ところで、冷却風は被冷却体である放熱部８を通過冷却する際、放熱部８からの発熱により温度上昇し排風口４より変換装置外へ排出される。この温度上昇した排風が、再び入風口３より冷却風洞５に入り込まぬよう、入風口３と排風口４とは変換装置筐体外表面の両端面となる垂直な二面に部分的に設けて距離がとられたり、あるいは変換装置の側面に入風口を設け、天井面に排風口を設けて入風口への排風の回り込みを防止している。
【００１０】
電動送風機６の小形軽量化と低騒音化の観点からは、冷却風洞５を真っ直ぐな構成として圧力損失を減らすことが重要であり、この従来例にみるように、入風口３と排風口４とを変換装置筐体外表面の両端面となる垂直な二面に設ける構成をとることが多い。
【００１１】
【発明が解決しようとする課題】
鉄道車両に搭載される電力変換装置は屋外環境で使用されるが、特に車両の屋根上に設置される変換装置は床下に設置される変換装置よりも外部環境に晒されることになり、降雪の多い地域での使用の場合は鉄道車両屋根上に積もる雪の影響を考慮する必要がある。特に、屋外に留置され運行していない状況で積雪があると、変換装置の周囲に雪が積もり、入風口、排風口に雪が付着し始め遂には雪で塞がれることもある。
【００１２】
図１０は図９の電力変換装置の周辺に雪が付着した状態を示す断面図である。電力変換装置１の入風口３および排風口４が降雪により付着した雪塊１０により塞がれており、この状態で電力変換装置１が動作すると冷却風洞５内に外気が入り込まず、被冷却体７を良好に冷却することができなくなる。従って、冷却風洞５内の入風部及び排風部での風の流れが絶たれており、大きな圧力損失が発生し、電動送風機６からの風量は著しく減少し、放熱部８への強制通風が充分に行えず、放熱部８の温度が上昇し、故障に至る恐れがある。
【００１３】
電動送風機６からの風量は著しく減少しているが、被冷却体である放熱部８の下流側となる排風口４では放熱部８の発熱により温度上昇した空気があたることで排風口４に付着した雪塊１０は次第に融けてくる可能性はあるが、入風口３側ではそれもなく、車両周囲温度が上昇して雪塊１０が溶けるのを待つしかない。電力変換装置１の周囲温度が低いにも関わらず、強制風冷式の電力変換装置ではこのような異常な温度上昇による故障が起こることになる。
【００１４】
このように付着した雪塊により入風口と排風口が塞がれた状態では、冷却風経路が遮られ、電動送風機による通風は著しく低下し冷却風洞内での冷却が問題となる。
【００１５】
本発明は、上記問題を解決するためになされたもので、その課題は入風口及び排風口が雪塊で塞がれた状態でも冷却風洞内を冷却風が循環し、冷却風洞内の被冷却体が異常な温度上昇となる前に外気を冷却風洞内へ取り込み正常な強制通風が可能な電力変換装置を提供することにある。
【００１６】
【課題を解決するための手段】
上記課題を解決するために請求項１に記載の発明は、半導体素子冷却ユニットの放熱部等の被冷却体及び電動送風機が収納される冷却風洞を内部に有し、この冷却風洞両端部には外気と通じる入風口と排風口が設け、前記電動送風機による強制通風により半導体素子他を冷却する鉄道車搭載の電力変換装置において、冷却風洞の排風口近傍の冷却風洞壁面と入風口近傍の冷却風洞壁面とをつなぐ別経路のバイパス風洞が冷却風洞の他に設けられ、このバイパス風洞の両端部は冷却風洞に開口して接続され、冷却風洞の排風口につながる部分から冷却風洞の入風口につながる部分に向かって冷却風洞の通風方向とは逆向きに空気が流れることが可能な構成となっていることを特徴とする。
【００１７】
請求項１によると、入風口及び排風口が雪塊により塞がれた場合、冷却風洞の排風口からこのバイパス風洞を通って冷却風が冷却風洞の入風口に循環され、電動送風機による通風が著しく低下することを防止すると共に、外気がこの循環経路内に取り込まれないことで空気温度は上昇するが、この温度上昇した空気により雪塊が融け始める。従来装置ではこのように温度上昇した空気で雪塊を融かすのは排風口側でしか実現できないが、このバイパス風洞を使った冷却風循環状態では入風口側でも温度上昇した空気があたるため、排風口、入風口の両方で雪塊が融解する。
【００１８】
請求項２に記載の発明は、請求項１記載の強制風冷式電力変換装置において、冷却風洞を部分的に冷却風の流れに沿って仕切り、風洞断面積の大なる側に半導体素子冷却ユニットの放熱部等の被冷却体及び前記電動送風機が設置され冷却風洞を形成し、風洞断面積の小なる側をバイパス風洞とし、入風口および排風口は電力変換装置の筐体内部で前記冷却風洞と前記バイパス風洞との間で空気が流れるように構成されていることを特徴とする。
【００１９】
請求項２によると、冷却風洞の一部をバイパス風洞として構成することで、電力変換装置内に容易にこれらの風洞が構成可能である。また請求項１と同様の効果が得られる。
【００２０】
請求項３に記載の発明は、半導体素子冷却ユニットの放熱部等の被冷却体及び電動送風機が収納される冷却風洞を内部に有し、この冷却風洞両端部には外気と通じる入風口と排風口が設け、前記電動送風機による強制通風により半導体素子他を冷却する鉄道車両屋根上設置形の電力変換装置において、前記変換装置上方に踏み板あるいは遮熱板等の板が前記変換装置筐体天井表面から所定の間隔を設けて設置され、この板が少なくとも前記冷却風洞の入風口近傍上部と排風口近傍上部とを連続的に覆い、前記変換装置筐体天井面上部に設けられた空間部分に向かって、前記冷却風洞は入風口近傍部分と排風口近傍部分の両方で上方に向かった開口部を設けたことを特徴とする。
【００２１】
請求項３によると、車両屋根上に設置される電力変換装置では、この変換装置筐体の上方に、保守要員が歩行する為の踏み板、あるいは直射日光による輻射熱での装置内の温度上昇抑制の為の遮熱板等が設けられるが、これら板と装置筐体との間の間隔部分は積雪時空間部分を形成することになる。この空間部分に冷却風洞の両端部が開口されてつながる構成にしておくことで、この空間部分はバイパス風洞として作用することになる。つまり冷却風洞の入風口近傍部分と排風口近傍部分の両方で上方装置筐体外部に向かった開口部があることで、冷却風洞排風口から冷却風は装置上面のこの空間部分へ流れ込み、冷却風洞入風口側で冷却風洞へ戻る循環経路が構成されることになる。
【００２２】
請求項４に記載の発明は、半導体素子冷却ユニットの放熱部等の被冷却体及び電動送風機が収納される冷却風洞を内部に有し、この冷却風洞両端部には外気と通じる入風口と排風口が設けられ、前記電動送風機による強制通風により半導体素子等を冷却する鉄道車両屋根上設置形の電力変換装置において、前記変換装置は鉄道車両屋根上面から所定の間隔を設けて設置されることで前記変換装置下面の外部下方に当該装置に覆われた空間部分を有し、この空間部分に向かって冷却風洞は入風口近傍部分と排風口近傍部分の両方で下方に向かった開口部を設けたことを特徴とする。
【００２３】
請求項４によると、車両屋根上に設置される電力変換装置を屋根上面から所定の間隔をとって設置した場合、降雪により冷却風洞の入風口と排風口および前記変換装置周辺が雪塊で塞がれた際に、この屋根上面と前記変換装置下面に設けられた空間部分はバイパス風洞として利用できる。つまり、冷却風洞の入風口近傍部分と排風口近傍部分の両方で下方装置筐体外部に向かった開口部があることで、冷却風洞排風口から冷却風は前記変換装置下面の空間部分へ流れ込み、冷却風洞入風口側で冷却風洞へ戻る循環経路が構成されることになる。
【００２４】
請求項５に記載の発明は、請求項１から請求項４のいずれかに記載の強制風冷式電力変換装置において、バイパス風洞あるいは装置筐体外の部分的に覆われた空間部分とつながる冷却風洞排風口近傍部分に設けられた開口部にルーバが設置され、このルーバは冷却風洞排風口中央部側に向かって傾斜していることを特徴とする。
【００２５】
請求項５によると、雪塊が付着した状態でない通常時、排風口近傍での空気流れを前記変換装置筐体外部側へ向かうようルーバが形成されていることで、冷却風が排風口から入風口側へ回りこんでしまうショートサーキットを防止する。
【００２６】
請求項６に記載の発明は、請求項１から請求項４のいずれかに記載の強制風冷式電力変換装置において、バイパス風洞あるいは装置筐体外の部分的に覆われた空間部分とつながる冷却風洞入風口近傍部分に設けられた開口部は、電動送風機と冷却風洞入風口との間にあり、その中間位置よりも冷却風洞入風口側に設けられていることを特徴とする。
【００２７】
請求項６によると、雪塊が付着した状態でない通常時、入風口部分で排風口から回り込んできた温度上昇した空気を吸い込みにくくし、冷却風が排風口から入風口側へ回りこんでしまうショートサーキットを防止する。
【００２８】
請求項７に記載の発明は、半導体素子冷却ユニットの放熱部等の被冷却体及び電動送風機が収納される冷却風洞を内部に有し、この冷却風洞両端部には外気と通じる入風口と排風口が設けられ、前記電動送風機による強制通風により半導体素子等を冷却する鉄道車両搭載の電力変換装置において、前記冷却風洞入風口にはヒータに設けられ、一方、前記変換装置筐体外部と前記冷却風洞入風口の前記変換装置筐体内部との２箇所に温度センサを設置し、この２箇所の温度の差が所定の値以上になったとき、前記ヒータを通電することを特徴とする。
【００２９】
請求項７によると、正常な状態では装置筐体外部と冷却風洞入風口の装置筐体内部の２箇所の温度は同一温度となるが、降雪により入風口が塞がれた状態では冷却風洞内部のみ温度上昇し始め、この２箇所には温度差が生じる。これを検知し、入風口のヒータに通電することで入風口の温度が上昇し雪塊を融解する。また、排風口側では電動送風機による強制通風で温度上昇した空気があたるので雪塊は融解され通常の強制通風状態になる。
【００３０】
請求項８に記載の発明は、半導体素子冷却ユニットの放熱部等の被冷却体及び電動送風機が収納される冷却風洞を内部に有し、この冷却風洞両端部には外気と通じる入風口と排風口が設けられ、電動送風機による強制通風により半導体素子等を冷却する鉄道車両搭載の電力変換装置において、前記変換装置筐体外部と前記冷却風洞入風口の前記変換装置筐体内部との２箇所に温度センサを設置し、この２箇所の温度の差が所定の値以上になったとき、前記電動送風機が逆向きに回転することを特徴とする。
【００３１】
請求項８によると、正常な状態では前記変換装置筐体外部と冷却風洞入風口の前記変換装置筐体内部との２箇所の温度は同一温度となるが、降雪により入風口が塞がれた状態では冷却風洞内部のみ温度上昇し始め、この２箇所には温度差が生じる。これを検知し、電動送風機を逆向きに回転させることで、温度上昇した冷却風を入風口側へ送風することで入風口の雪塊を融解する。入風口での雪塊が融解すると、２箇所の温度センサ部分の温度差は無くなり、再び通常方向へ電動送風機は回転し、温度上昇した空気は冷却風洞下流側の排風口へあたることになり、排風口の雪塊を融解し、通常の強制通風状態となる。また、入風口をビニル、紙等が塞いでしまう異常状態でも同様の作用により電動送風機は逆向きに回転し、この入風口を塞いだ異物を吹き飛ばすことも可能である。
【００３２】
【発明の実施の形態】
以下、本発明の実施の形態を図を参照して説明する。
図１は本発明の第１の実施形態（請求項１及び請求項２対応）の天井板を除いた電力変換装置の平面図である。
【００３３】
図に示すように、本実施形態の電力変換装置１は、鉄道車両屋根２上に設置され、装置内には半導体素子冷却ユニット７の放熱部（図示せず）などの被冷却体及び電動送風機６が収納される冷却風洞５が構成されており、さらに、冷却風洞５の両端には外気と通じる入風口３と排風口４を設け、排風口近傍の風洞壁面と入風口近傍の風洞壁面とをつなぐバイパス風洞１１が構成されている。
【００３４】
次に、本実施形態の作用を説明する。積雪により入風口３及び排風口４が塞がれた場合、電動送風機５による冷却風は排風口近傍からのバイパス風洞１１を通って入風口近傍の壁面の入風側にまわり、外気を取り込めない状態で循環し、筐体内部空気温度が上昇する。積雪環境下でのバイパス風洞の循環による筐体内温度上昇により、排風口、入風口の両側の雪塊が解け始めて外気の新鮮な空気を取り込み正常な強制通風が可能となる。
【００３５】
図２は本発明の第２の実施形態（請求項３対応）の断面図である。
図に示すように、本実施形態では、図１の第１の実施形態と同様に電力変換装置１を鉄道車両屋根２上に設置し、装置内には被冷却体及び電動送風機６が収納される冷却風洞５を構成し、さらにこの冷却風洞５の両端に外気と通じる入風口３と排風口４を形成する。電力変換装置１の上方には踏み板あるいは遮熱板等の板１２が電力変換装置天井表面から所定の間隔を設けて設置する。この板１２は中空構成で冷却風洞５の排気口近傍上部と入風口近傍上部を覆う形状となっており、この板１２を取付け固定することによりバイパス風洞１１が形成される。
【００３６】
次に、本実施形態の作用を説明する。積雪により入風口３、排風口４が塞がれた場合、電動送風機６による冷却風は排気口近傍から電力変換装置１の天井面に取付けた踏み板あるいは遮熱板等の板１２のバイパス風洞１１を通って入風口近傍の壁面にまわり、外気を取り込めない状態で循環するため、次第に筐体内空気温度が上昇する。従って、積雪環境下でのバイパス風洞の循環による筐体内温度上昇により、排風口、入風口の両側の雪塊が解け始めて外気の新鮮な空気を取り込み正常な強制通風が可能となる。
【００３７】
図３は、本発明の第３の実施形態（請求項４対応）の断面図である。
図に示すように、本実施形態では、図１の第１の実施形態と同様に、被冷却体及び電動送風機６が収納される冷却風洞５と、この冷却風洞５の両端に外気と通じる入風口３と排風口４を設けた電力変換装置１を、鉄道車両屋根２上に所定の間隔を設けて設置し、電力変換装置１の下面と鉄道車両屋根２上面の間に空間部分を有する構成とする。入風口３近傍付近部分と排風口４近傍付近部分の両方の下方部分に開口部を設けて空間部分内にバイパス風洞１１を形成する。
【００３８】
次に、本実施形態の作用を説明する。積雪により入風口３及び排風口４が塞がれた場合、電動送風機６による冷却風は排風口近傍から、鉄道車両屋根２上面と変換装置下面の間に設けられた空間部分のバイパス風洞１１を通って入風口近傍の壁面の入風側にまわり、外気を取り込めない状態で循環し、次第に筐体内空気温度が上昇する。従って、積雪環境下でのバイパス風洞への循環による筐体内温度上昇により、排風口、入風口の両側の雪塊が解け始めて外気の新鮮な空気を取り込み正常な強制通風が可能となる。
【００３９】
図４は、本発明の第４の実施形態（請求項５対応）の天井板を除いた断面図である。
図に示すように、本実施形態では、図１の第１の実施形態と同様に、被冷却体及び電動送風機６が収納される冷却風洞５を設け、この冷却風洞５の両端に外気と通じる入風口３、排風口４を設ける。この冷却風洞５の排風口近傍の風洞壁面と入風口近傍の風洞壁面とをつなぐバイパス風洞１１を設け、排風口近傍の風洞壁面に設けられた開口部には排気口中央部側に向かって傾斜しているルーバ１３を取付けている。
【００４０】
次に、本実施形態の作用について説明する。積雪により入風口３及び排風口４が塞がれた場合、電動送風機６による冷却風は排気口近傍から、鉄道車両屋根２の上面と装置下面の間に設けられた空間部分のバイパス風洞１１を通って入風口近傍の壁面の入風側にまわるが、積雪がない通常の環境下で入風口３から排風口４への冷却風の流れがスムーズとなる。従って、通常環境下での冷却風洞の冷却風の流れがルーバ１３によりスムーズとなり、排風口４から入風口３側への回り込むショートカットを防止することが可能となる。
【００４１】
図５は、本発明の第５の実施形態（請求項６対応）の天井板を除いた断面図である。
図に示すように、本実施形態では、図１の第１の実施形態と同様に、被冷却体及び電動送風機６が収納される冷却風洞５を構成し、この風洞の両端には外気と通じる入風口３と排風口４を設け、さらに入風口近傍の風洞壁面と排風口近傍の風洞壁面とをつなぐバイパス風洞１１を設けている。バイパス風洞１１の入風口近傍の風洞壁面との開口部の位置が、電動送風機６と冷却風洞入風口の中間位置より風洞入風口寄りに設けることにより、積雪のない通常の風流時にバイパス風洞１１からの回り込んだ空気を吸い込みにくくしショートカットを防止する効果がある。
【００４２】
図６は、本発明の第６の実施形態（請求項７に対応）の断面図である。
図に示すように、本実施形態の電力変換装置１は、鉄道車両屋根２上に設置され、変換装置内には半導体素子冷却ユニット７の放熱部８などの被冷却体及び電動送風機６が収納される冷却風洞５を設け、この冷却風洞５の両端には外気と通じる入風口３および排風口４を配置し、入風口３にはヒータ１４を設け、さらに温度センサ１５を変換装置筐体外部と冷却風洞入口内部に配置している。
【００４３】
次に、本実施形態の作用について説明する。積雪等により入風口３が塞がれた場合、冷却風洞内部が温度上昇し変換装置筐体外部と温度差が生じ、これを２個の温度センサ１５により検知し、所定の値以上になった時にヒータ１４を通電する。このように、積雪により入風口が塞がれ変換装置内外の温度差を検知することによりヒータ通電となり、入風口の温度が上昇して雪塊を融解し通常の強制通風状態になる。
【００４４】
図７は、本発明の第７の実施形態（請求項８対応）の断面図である。
図に示すように、本実施形態の電力変換装置１は、鉄道車両屋根２上に設置され、変換装置内には半導体素子冷却ユニット７の放熱部８などの被冷却体及び電動送風機６が収納される冷却風洞５と、この冷却風洞５の両端には外気と通じる入風口３と排風口４を設け、さらに温度センサ１５を変換装置筐体外部と冷却風洞入口内部１２に配置した構成としている。
【００４５】
次に、本実施形態の作用について説明する。積雪等により入風口３が塞がれた場合、冷却風洞５内部が温度上昇し、変換装置筐体外部と温度差が生じ、これを２個の温度センサ１５により検知し、所定の値以上になった時に電動送風機６の回転を逆向きにする。このように、積雪等により入風口が塞がれ装置内外の温度差を検知することにより、電動送風機の回転を逆向きにすることで、温度上昇した冷却風洞内部の空気を入風口側へ送風することにより、入風口の雪塊を融解し通常の強制通風状態になる。また、ビニール、紙などの異物による入風口の塞ぎに対しても、電動送風機の逆回転により入風口を塞いだ異物を吹き飛ばすことが可能となる。
【００４６】
【発明の効果】
以上説明したように、本発明によれば、積雪による入風口を塞いだ雪塊を融解し、冷却風の取り込みが可能となり、電力変換装置の鉄道車両屋根上設置の品質向上が実現できる。
【図面の簡単な説明】
【図１】本発明の第１の実施形態の天井板を除いた電力変換装置の平面図。
【図２】本発明の第２の実施形態の電力変換装置の断面図。
【図３】本発明の第３の実施形態の電力変換装置の断面図。
【図４】本発明の第４の実施形態の天井板を除いた電力変換装置の平面図。
【図５】本発明の第５の実施形態の天井板を除いた電力変換装置の平面図。
【図６】本発明の第６の実施形態の電力変換装置の断面図。
【図７】本発明の第７の実施形態の電力変換装置の断面図。
【図８】従来の電力変換装置を鉄道車両屋根上に取付けた平面図。
【図９】図８の断面図。
【図１０】図９において積雪した状態を示す断面図。
【符号の説明】
１…電力変換装置、２…鉄道車両屋根、３…入風口、４…排風口、５…冷却風洞、６…電動送風機、７…半導体冷却ユニット、８…放熱部、９…電気部品実装部、１０…雪塊、１１…バイパス風洞、１２…踏み板（遮熱板）、１３…ルーバ、１４…ヒータ、１５…温度センサ。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a forced air-cooled power converter mounted on a railway vehicle.
[0002]
[Prior art]
In a power converter that cools a semiconductor element mounted on a railway vehicle by forced ventilation by an electric blower, an inlet and an outlet are provided on an outer surface of the converter housing, and these are provided at both ends. A cooling wind tunnel is formed inside the apparatus, and the cooling wind tunnel accommodates an electric blower for ventilation and a cooled body such as a heat radiating portion of a semiconductor element cooling unit.
[0003]
Usually, in order to prevent the exhaust air with the increased air temperature from entering the cooling air tunnel from the air inlet again (generally called a short circuit of the cooling air), it is designed to install the air inlet and the air outlet as far apart as possible. , So that it is difficult to cause a short circuit.
[0004]
Also, by reducing the pressure loss at the inlet and outlet, cooling air can efficiently enter and exit the cooling air tunnel, thereby preventing the electric blower from becoming large. Noise generated from the vehicle.
[0005]
Next, a conventional power converter installed on the roof of a railway vehicle will be specifically described with reference to FIGS.
FIG. 8 is a plan view in which a conventional power converter is mounted on a roof of a railway vehicle, and FIG. 9 is a cross-sectional view of the power converter in FIG.
[0006]
The power converter 1 is installed on a railcar roof 2, and an air inlet 3 is installed on one vertical outer surface of the converter housing and an air outlet 4 is installed on a vertical outer surface on the opposite side. Further, a cooling wind tunnel 5 is formed inside the power conversion device 1 such that the inlet 3 and the outlet 4 are at both end surfaces.
[0007]
An electric blower 6 and a cooled object are accommodated in the cooling wind tunnel 5. Here, the object to be cooled refers to a heat generating device that needs to dissipate heat to the outside air, such as a heat radiating portion of a semiconductor element cooling unit, a roll of a transformer, a reactor, or the like. Such an object to be cooled is cooled by the electric blower 6 by forced ventilation of the outside air taken into the cooling wind tunnel 5 from the air inlet 3. In this conventional example, the heat radiating portion 8 of the semiconductor element cooling unit 7 is a cooled object, the cooling wind tunnel 5 is attached to the lower side in the converter housing, and the semiconductor element cooling unit 7 is powered so that the heat radiating portion 8 is located below. It is housed in the housing of the conversion device 1.
[0008]
Here, in the power converter 1 installed on the roof of the railway vehicle, since the access is made from above the converter housing, the heat radiating portion 8 of the semiconductor element cooling unit 7 is located below and the electric component mounting portion 9 is located above. It is configured such that the electrical component mounting unit 9 can be easily accessed from above the device housing.
When the cooling wind tunnel 5 is configured on the lower side in the converter housing as described above, the inlet 3 and the outlet 4 are inevitably often installed relatively lower than the converter housing.
[0009]
By the way, when the cooling air passes through the heat radiating portion 8 as a cooled body and cools, the temperature rises due to the heat generated from the heat radiating portion 8 and is discharged from the air outlet 4 to the outside of the converter. The inlet 3 and the outlet 4 are partially provided on two vertical surfaces that are both end surfaces of the outer surface of the conversion device housing so that the exhausted air having the increased temperature does not enter the cooling wind tunnel 5 from the inlet 3 again. A distance is provided, or an air inlet is provided on the side surface of the converter, and an air outlet is provided on the ceiling surface to prevent the exhaust air from flowing into the air inlet.
[0010]
From the standpoint of reducing the size and weight of the electric blower 6 and reducing noise, it is important to reduce the pressure loss by making the cooling wind tunnel 5 straight, and as shown in this conventional example, the inlet 3 and the outlet 4 Are provided on two vertical surfaces that are both end surfaces of the outer surface of the converter housing.
[0011]
[Problems to be solved by the invention]
Power converters installed in railway vehicles are used in outdoor environments, but converters installed on the roof of the vehicle are more exposed to the external environment than converters installed under the floor, especially in snowfall. In the case of use in many areas, it is necessary to consider the effect of snow on the roof of the railway vehicle. In particular, if there is snow in a situation where the vehicle is left outdoors and the vehicle is not operating, snow may accumulate around the converter, and snow may start to adhere to the air inlet and the air outlet, and may eventually be blocked by the snow.
[0012]
FIG. 10 is a cross-sectional view showing a state where snow adheres to the periphery of the power converter of FIG. The air inlet 3 and the air outlet 4 of the power converter 1 are closed by a snow mass 10 attached by snowfall, and when the power converter 1 operates in this state, no outside air enters the cooling wind tunnel 5 and the cooled object 7 cannot be cooled well. Therefore, the flow of air at the air inlet and the air outlet in the cooling wind tunnel 5 is cut off, a large pressure loss is generated, the air volume from the electric blower 6 is significantly reduced, and forced ventilation to the heat radiating unit 8 is performed. Is not sufficiently performed, and the temperature of the heat radiating section 8 rises, which may lead to failure.
[0013]
Although the air volume from the electric blower 6 is significantly reduced, the air whose temperature has risen due to the heat generated by the heat radiating section 8 hits the exhaust port 4 on the downstream side of the heat radiating section 8 which is the object to be cooled. Although there is a possibility that the snow mass 10 gradually melts, there is no such thing on the side of the air inlet 3 and there is no choice but to wait until the vehicle surrounding temperature rises and the snow mass 10 melts. Although the ambient temperature of the power converter 1 is low, a failure due to such abnormal temperature rise occurs in the forced air cooling type power converter.
[0014]
In a state where the air inlet and the air outlet are blocked by the snow clumps thus adhered, the cooling air path is blocked, the ventilation by the electric blower is significantly reduced, and cooling in the cooling air tunnel becomes a problem.
[0015]
The present invention has been made to solve the above-mentioned problem, and the problem is that cooling air circulates in the cooling wind tunnel even when the inlet and outlet are closed with snow chunks, and the cooling target in the cooling wind tunnel is cooled. An object of the present invention is to provide a power converter capable of taking in outside air into a cooling wind tunnel before an abnormal rise in temperature of a body and enabling normal forced ventilation.
[0016]
[Means for Solving the Problems]
In order to solve the above problem, the invention according to claim 1 has a cooling wind tunnel in which a cooled object such as a heat radiating portion of a semiconductor element cooling unit and an electric blower are housed, and both ends of the cooling wind tunnel are provided. In a power converter mounted on a railway car, provided with an air inlet and an air outlet communicating with the outside air, and cooling semiconductor elements and the like by forced ventilation by the electric blower, a cooling wind tunnel wall near the air outlet of the cooling wind tunnel and a cooling wind tunnel near the air inlet are provided. A bypass wind tunnel of another route connecting the wall and the wall is provided in addition to the cooling wind tunnel, and both ends of this bypass wind tunnel are connected to the cooling wind tunnel by opening, and the part connected to the exhaust vent of the cooling wind tunnel is connected to the inlet of the cooling wind tunnel It is characterized in that air is allowed to flow in the direction opposite to the direction of air flow in the cooling tunnel toward the portion.
[0017]
According to the first aspect, when the air inlet and the air outlet are blocked by snow mass, the cooling air is circulated from the air outlet of the cooling air tunnel to the air inlet of the cooling air tunnel through the bypass air tunnel, and the ventilation by the electric blower is reduced. The temperature is prevented from dropping remarkably, and the air temperature rises because the outside air is not taken into the circulation path. However, the snow mass starts to melt due to the air having the increased temperature. In the conventional device, melting the snow mass with the air whose temperature has increased in this way can be realized only on the exhaust port side, but in the cooling air circulation state using this bypass wind tunnel, the air whose temperature has increased on the inlet port side hits, The snow mass melts at both the outlet and the inlet.
[0018]
According to a second aspect of the present invention, in the forced air cooling type power converter according to the first aspect, the cooling wind tunnel is partially partitioned along the flow of the cooling wind, and the semiconductor element cooling unit is provided on the side having the larger cross-sectional area of the wind tunnel. A cooling object such as a heat radiating portion and the electric blower are installed to form a cooling wind tunnel, and a side having a small cross-sectional area of the wind tunnel is a bypass wind tunnel, and an inlet and an exhaust outlet are provided inside the casing of the power conversion device. And the bypass wind tunnel is configured to allow air to flow.
[0019]
According to the second aspect, by configuring a part of the cooling wind tunnel as a bypass wind tunnel, these wind tunnels can be easily configured in the power converter. Further, the same effect as the first aspect can be obtained.
[0020]
According to a third aspect of the present invention, there is provided a cooling air tunnel in which a cooled object such as a heat radiating portion of the semiconductor element cooling unit and an electric blower are housed, and both ends of the cooling air tunnel have an air inlet and an exhaust air communicating with outside air. In a power converter installed on the roof of a railway vehicle for cooling a semiconductor element and the like by forced ventilation by the electric blower provided with an air vent, a plate such as a tread plate or a heat shield plate is provided above the converter in a ceiling surface of the converter housing. This plate is provided at a predetermined interval from the upper surface, and the plate continuously covers at least the upper part near the air inlet and the upper part near the air outlet of the cooling wind tunnel, and faces the space provided at the upper part of the ceiling surface of the converter housing. The cooling wind tunnel is provided with openings facing upward both in the vicinity of the inlet and in the vicinity of the outlet.
[0021]
According to the third aspect of the present invention, in the power converter installed on the roof of the vehicle, a step plate for maintenance personnel to walk or a rise in temperature inside the device due to radiant heat due to direct sunlight is provided above the converter housing. For this purpose, a heat shield plate or the like is provided, but the space between these plates and the device casing forms a snow-covered space portion. By providing a configuration in which both ends of the cooling wind tunnel are opened and connected to this space, this space acts as a bypass wind tunnel. In other words, since there are openings facing the outside of the upper device housing both in the vicinity of the inlet and the outlet of the cooling wind tunnel, the cooling air flows from the outlet of the cooling wind tunnel into this space on the upper surface of the device, and the cooling wind tunnel A circulation path returning to the cooling wind tunnel is formed on the inlet side.
[0022]
According to a fourth aspect of the present invention, there is provided a cooling wind tunnel in which a cooling target such as a heat radiating portion of a semiconductor element cooling unit and an electric blower are housed. An air vent is provided, in a power converter installed on the roof of a railway vehicle that cools semiconductor elements and the like by forced ventilation by the electric blower, the converter is installed at a predetermined interval from the upper surface of the roof of the railway vehicle. A space portion covered by the device is provided below the outside of the lower surface of the conversion device, and the cooling wind tunnel is provided with openings facing downward in both the vicinity of the air inlet and the portion near the air outlet toward the space. It is characterized by the following.
[0023]
According to claim 4, when the power converter installed on the vehicle roof is installed at a predetermined interval from the roof upper surface, the snowfall blocks the inlet and outlet of the cooling wind tunnel and the periphery of the converter with snow. When the roof is separated, the space provided between the upper surface of the roof and the lower surface of the converter can be used as a bypass wind tunnel. That is, since there are openings facing the outside of the lower device housing in both the vicinity of the inlet and the vicinity of the outlet of the cooling wind tunnel, the cooling air flows from the outlet of the cooling wind tunnel into the space on the lower surface of the converter, A circulation path returning to the cooling wind tunnel is formed on the cooling wind tunnel entrance side.
[0024]
According to a fifth aspect of the present invention, in the forced air cooling type power converter according to any one of the first to fourth aspects, a cooling wind tunnel connected to a bypass wind tunnel or a partially covered space outside the device housing. A louver is provided in an opening provided near the air outlet, and the louver is characterized by being inclined toward the center of the cooling air outlet.
[0025]
According to the fifth aspect, the louvers are formed so as to direct the air flow near the air outlet to the outside of the converter casing when the snow lump is not normally attached, so that the cooling air enters from the air outlet. Prevents a short circuit going around the wind vent.
[0026]
According to a sixth aspect of the present invention, in the forced air cooling type power converter according to any one of the first to fourth aspects, a cooling wind tunnel connected to a bypass wind tunnel or a partially covered space outside the apparatus housing. The opening provided in the vicinity of the air inlet is provided between the electric blower and the cooling air inlet, and is provided closer to the cooling air inlet than the intermediate position.
[0027]
According to the sixth aspect, when the snow lump is not in a normal state, it is difficult to suck the temperature-increased air that has flowed from the air outlet at the air inlet, and the cooling air flows from the air outlet toward the air inlet. Prevent short circuits.
[0028]
According to a seventh aspect of the present invention, there is provided a cooling wind tunnel in which a cooling target such as a heat radiating portion of a semiconductor element cooling unit and an electric blower are housed, and both ends of the cooling wind tunnel have an air inlet and an exhaust which communicate with outside air. In a power converter mounted on a railway vehicle, which is provided with an air port and cools a semiconductor element or the like by forced ventilation by the electric blower, the cooling air tunnel is provided with a heater at an air inlet, while the cooling device outside the housing and the cooling device are provided with a heater. Temperature sensors are installed at two locations of the wind tunnel entrance and the inside of the converter housing, and the heater is energized when the difference between the temperatures at the two locations becomes a predetermined value or more.
[0029]
According to claim 7, the temperature of the outside of the device casing and the temperature of two points inside the device casing at the inlet of the cooling wind tunnel become the same temperature in a normal state, but the inside of the cooling wind tunnel when the inlet is closed by snowfall. Only the temperature starts to rise, and a temperature difference occurs between these two locations. By detecting this and energizing the heater of the air inlet, the temperature of the air inlet rises and the snow chunk is melted. In addition, since the air whose temperature has risen due to forced ventilation by the electric blower hits the exhaust port side, the snow chunks are melted and a normal forced ventilation state is established.
[0030]
The invention according to claim 8 has a cooling air tunnel in which a cooled object such as a heat radiating portion of the semiconductor element cooling unit and an electric blower are housed inside, and both ends of the cooling air tunnel have an air inlet and an exhaust air communicating with the outside air. In a power converter mounted on a railway vehicle that is provided with an air vent and cools a semiconductor element or the like by forced ventilation by an electric blower, at two places: outside the converter housing and inside the converter housing at the cooling-air tunnel inlet. A temperature sensor is provided, and when the temperature difference between the two locations becomes equal to or greater than a predetermined value, the electric blower rotates in the opposite direction.
[0031]
According to claim 8, in a normal state, the temperature of the outside of the converter housing and the temperature of the cooling wind tunnel inlet inside the converter housing are the same, but the inlet is closed by snowfall. In this state, the temperature starts to rise only in the cooling wind tunnel, and a temperature difference occurs between these two locations. By detecting this and rotating the electric blower in the opposite direction, the cooling air whose temperature has risen is blown to the air inlet side to melt the snow mass at the air inlet. When the snow mass at the air inlet melts, the temperature difference between the two temperature sensors disappears, the electric blower rotates again in the normal direction, and the air whose temperature has risen hits the air outlet downstream of the cooling tunnel. The snow mass at the air outlet is melted, and normal forced ventilation is established. Further, even in an abnormal state in which the air inlet is blocked by vinyl, paper, or the like, the electric blower rotates in the opposite direction by the same action, and it is possible to blow off the foreign matter that has closed the air inlet.
[0032]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view of a power conversion device according to a first embodiment of the present invention (corresponding to claims 1 and 2) without a ceiling plate.
[0033]
As shown in the figure, a power conversion device 1 of the present embodiment is installed on a railcar roof 2 and includes a cooled object such as a heat radiating portion (not shown) of a semiconductor element cooling unit 7 and an electric blower. A cooling wind tunnel 5 for accommodating the cooling air tunnel 6 is formed. Further, at both ends of the cooling wind tunnel 5, an inlet 3 and an exhaust outlet 4 communicating with the outside air are provided, and a wall of the wind tunnel near the outlet and a wall of the wind tunnel near the inlet are provided. Is formed.
[0034]
Next, the operation of the present embodiment will be described. When the air inlet 3 and the air outlet 4 are blocked by snow, the cooling air from the electric blower 5 passes through the bypass wind tunnel 11 from the vicinity of the air outlet to the air inlet side of the wall near the air inlet, and cannot take in outside air. It circulates in the state, and the air temperature inside the housing rises. Due to the temperature rise in the housing due to the circulation of the bypass wind tunnel in the snow-covered environment, the snow mass on both sides of the exhaust port and the inlet port begins to melt, and fresh air of the outside air is taken in, enabling normal forced ventilation.
[0035]
FIG. 2 is a sectional view of a second embodiment (corresponding to claim 3) of the present invention.
As shown in the figure, in the present embodiment, the power conversion device 1 is installed on the roof 2 of a railway vehicle as in the first embodiment of FIG. 1, and the device to be cooled and the electric blower 6 are housed in the device. A cooling wind tunnel 5 is formed, and an inlet port 3 and an exhaust port 4 communicating with the outside air are formed at both ends of the cooling wind tunnel 5. Above the power converter 1, a plate 12, such as a tread or a heat shield, is provided at a predetermined distance from the ceiling surface of the power converter. The plate 12 has a hollow configuration and covers the upper portion near the exhaust port and the upper portion near the air inlet of the cooling wind tunnel 5. By attaching and fixing the plate 12, the bypass wind tunnel 11 is formed.
[0036]
Next, the operation of the present embodiment will be described. When the inlet 3 and the outlet 4 are blocked by snow, the cooling air from the electric blower 6 is supplied from the vicinity of the outlet to a bypass wind tunnel 11 of a plate 12 such as a tread plate or a heat shield plate attached to the ceiling surface of the power converter 1. Then, the air circulates in a state where outside air cannot be taken in, and circulates around the wall near the air inlet, so that the air temperature inside the housing gradually increases. Therefore, due to the temperature rise in the housing due to the circulation of the bypass wind tunnel in the snowy environment, the snow mass on both sides of the exhaust port and the inlet port begins to melt, and fresh air of the outside air is taken in and normal forced ventilation can be performed.
[0037]
FIG. 3 is a sectional view of a third embodiment (corresponding to claim 4) of the present invention.
As shown in the drawing, in the present embodiment, similarly to the first embodiment of FIG. 1, a cooling wind tunnel 5 in which a body to be cooled and an electric blower 6 are accommodated, and both ends of the cooling wind tunnel 5 that communicate with outside air. A configuration in which a power converter 1 provided with an air vent 3 and an exhaust vent 4 is installed at a predetermined interval on a railcar roof 2 and has a space between a lower surface of the power converter 1 and an upper surface of the railcar roof 2. And Openings are provided in both the lower part of the vicinity near the inlet 3 and the part near the outlet 4 to form the bypass wind tunnel 11 in the space.
[0038]
Next, the operation of the present embodiment will be described. When the inlet 3 and the outlet 4 are blocked by the snow, the cooling air from the electric blower 6 flows from the vicinity of the outlet to the bypass wind tunnel 11 in the space provided between the upper surface of the railcar roof 2 and the lower surface of the converter. As a result, the air circulates around the air inlet side of the wall near the air inlet and circulates in a state where external air cannot be taken in, and the air temperature in the housing gradually increases. Therefore, due to the temperature rise in the housing due to the circulation to the bypass wind tunnel in the snowy environment, the snow mass on both sides of the exhaust port and the inlet port begins to melt, and fresh air of outside air is taken in and normal forced ventilation can be performed.
[0039]
FIG. 4 is a sectional view of a fourth embodiment (corresponding to claim 5) of the present invention, from which a ceiling plate is removed.
As shown in the drawing, in the present embodiment, similarly to the first embodiment of FIG. 1, a cooling wind tunnel 5 in which a cooled object and an electric blower 6 are stored is provided, and both ends of the cooling wind tunnel 5 communicate with outside air. An inlet 3 and an outlet 4 are provided. A bypass wind tunnel 11 is provided to connect the wall of the cooling wind tunnel 5 near the air outlet to the wall of the air tunnel near the air inlet, and the opening provided on the wall of the wind tunnel near the air outlet is inclined toward the center of the air outlet. Louver 13 is attached.
[0040]
Next, the operation of the present embodiment will be described. When the inlet 3 and the outlet 4 are blocked by snow, the cooling air from the electric blower 6 flows from the vicinity of the outlet to the bypass wind tunnel 11 in the space provided between the upper surface of the railcar roof 2 and the lower surface of the device. The cooling air flows from the air inlet 3 to the air outlet 4 under a normal environment with no snow accumulation. Therefore, the flow of the cooling air in the cooling air tunnel under the normal environment is smoothed by the louver 13, and it is possible to prevent a short-cut from the exhaust port 4 to the inlet port 3 side.
[0041]
FIG. 5 is a sectional view of a fifth embodiment (corresponding to claim 6) of the present invention, from which a ceiling plate is removed.
As shown in the drawing, in the present embodiment, similarly to the first embodiment of FIG. 1, a cooling wind tunnel 5 in which a cooled object and an electric blower 6 are housed is formed, and both ends of the wind tunnel communicate with outside air. An air inlet 3 and an air outlet 4 are provided, and a bypass air tunnel 11 that connects a wind tunnel wall near the air inlet and a wind tunnel wall near the air outlet is provided. By providing the opening of the bypass wind tunnel 11 near the wind tunnel wall near the inlet of the wind tunnel from the intermediate position between the electric blower 6 and the cooling wind tunnel entrance, the bypass wind tunnel 11 is closed from the bypass wind tunnel 11 during normal wind without snow. This has the effect of making it difficult to suck in the air that has flowed around and preventing shortcuts.
[0042]
FIG. 6 is a sectional view of a sixth embodiment (corresponding to claim 7) of the present invention.
As shown in the figure, a power converter 1 of the present embodiment is installed on a railcar roof 2, and a cooled object such as a heat radiating portion 8 of a semiconductor element cooling unit 7 and an electric blower 6 are housed in the converter. A cooling wind tunnel 5 is provided, and at both ends of the cooling wind tunnel 5, an inlet 3 and an outlet 4 communicating with the outside air are arranged, a heater 14 is provided at the inlet 3, and a temperature sensor 15 is provided outside the converter housing. And it is located inside the cooling wind tunnel entrance.
[0043]
Next, the operation of the present embodiment will be described. When the air inlet 3 is closed by snow or the like, the temperature inside the cooling wind tunnel rises, and a temperature difference is generated with the outside of the converter housing. This is detected by the two temperature sensors 15 and exceeds a predetermined value. At this time, the heater 14 is energized. As described above, the inlet is closed by the snow and the heater is energized by detecting a temperature difference between the inside and the outside of the converter, and the temperature of the inlet rises to melt the snow chunks and to enter a normal forced ventilation state.
[0044]
FIG. 7 is a sectional view of a seventh embodiment (corresponding to claim 8) of the present invention.
As shown in the figure, a power converter 1 of the present embodiment is installed on a railcar roof 2, and a cooled object such as a heat radiating portion 8 of a semiconductor element cooling unit 7 and an electric blower 6 are housed in the converter. A cooling wind tunnel 5 is provided, and an inlet port 3 and an exhaust port 4 communicating with the outside air are provided at both ends of the cooling wind tunnel 5, and a temperature sensor 15 is arranged outside the converter housing and inside the cooling wind tunnel inlet 12. .
[0045]
Next, the operation of the present embodiment will be described. When the air inlet 3 is closed by snow or the like, the temperature inside the cooling wind tunnel 5 rises, and a temperature difference is generated between the outside of the converter housing and the two temperature sensors 15. When this happens, the rotation of the electric blower 6 is reversed. In this way, by detecting the temperature difference between the inside and the outside of the device by detecting the temperature difference between the inside and outside of the device due to the snow cover or the like, the rotation of the electric blower is reversed, so that the air inside the cooling wind tunnel, whose temperature has increased, is blown to the inlet side. By doing so, the snow mass at the inlet is melted and a normal forced ventilation state is established. Further, even when the air inlet is closed by foreign matter such as vinyl or paper, the foreign matter that has closed the air inlet can be blown away by the reverse rotation of the electric blower.
[0046]
【The invention's effect】
As described above, according to the present invention, it is possible to melt a snow block that blocks an air inlet due to snow and take in cooling air, thereby improving the quality of the power converter installed on a railroad vehicle roof.
[Brief description of the drawings]
FIG. 1 is a plan view of a power converter without a ceiling plate according to a first embodiment of the present invention.
FIG. 2 is a sectional view of a power converter according to a second embodiment of the present invention.
FIG. 3 is a sectional view of a power converter according to a third embodiment of the present invention.
FIG. 4 is a plan view of a power conversion device excluding a ceiling plate according to a fourth embodiment of the present invention.
FIG. 5 is a plan view of a power conversion device excluding a ceiling plate according to a fifth embodiment of the present invention.
FIG. 6 is a sectional view of a power converter according to a sixth embodiment of the present invention.
FIG. 7 is a sectional view of a power converter according to a seventh embodiment of the present invention.
FIG. 8 is a plan view in which a conventional power converter is mounted on a railcar roof.
FIG. 9 is a sectional view of FIG. 8;
FIG. 10 is a sectional view showing a state where snow is accumulated in FIG. 9;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Power conversion device, 2 ... Railway car roof, 3 ... Air inlet, 4 ... Air outlet, 5 ... Cooling wind tunnel, 6 ... Electric blower, 7 ... Semiconductor cooling unit, 8 ... Heat radiating unit, 9 ... Electric component mounting unit, 10: snow mass, 11: bypass wind tunnel, 12: tread plate (heat shield plate), 13: louver, 14: heater, 15: temperature sensor.
