JP3785875B2

JP3785875B2 - centrifuge

Info

Publication number: JP3785875B2
Application number: JP28352099A
Authority: JP
Inventors: 伸二渡部; 雅裕稲庭; 哲州沼田
Original assignee: Hitachi Koki Co Ltd
Current assignee: Koki Holdings Co Ltd
Priority date: 1999-10-04
Filing date: 1999-10-04
Publication date: 2006-06-14
Anticipated expiration: 2019-10-04
Also published as: JP2001112292A

Description

【０００１】
【発明の属する技術分野】
本発明は、遠心分離用ロータを駆動するモータの制御装置特にインバータ制御装置において、いわゆるＤＣリンク電圧を測定する平滑コンデンサ電圧センサの校正に関するものである。
【０００２】
【従来の技術】
従来の遠心機用モータの制御装置は特開平7−246351号公報に記載のように、交流側はリアクトルを介し交流電源に接続され直流側は平滑コンデンサに接続される電源用双方向電力変換器と、交流側はモータに接続され直流側は平滑用コンデンサに接続されるモータ用双方向電力変換器を設け、モータの力行・電源回生運転に際し、力率改善制御回路に電源電圧波形と平滑コンデンサ電圧と電源電流波形をフィードバックし、力率改善用ＩＣから出力されるＰＷＭ制御信号を基に、電源用双方向電力変換器のスイッチング素子をオン・オフさせ、遠心機用ロータを加速するためのモータ力行運転時は平滑コンデンサの充電電圧を電源電圧のピーク値よりも高い電圧に保つようにリアクトルと電源用双方向電力変換器を昇圧コンバータとして動作させ、ロータを減速させるためのモータの電力回生時に於いては平滑コンデンサの充電電圧は電源電圧のピーク値よりも高い電圧に調節しつつリアクトルと電源用双方向電力変換器を降圧コンバータとして動作させることにより、交流電源電流を力行、回生時とも高力率で高調波電流を低減させたものとしていた。
【０００３】
図３の力率改善用ＩＣのブロック機能図を用いて力率改善用ＩＣ１３の動作を説明すると、直流基準電圧４１と、平滑コンデンサ電圧センサ１１から出力される平滑コンデンサの充電電圧フィードバック信号Vinを抵抗器４０、４２とフィルタコンデンサ４３とオペアンプ４４により誤差増幅し電圧誤差増幅信号Vfbを得る。電圧誤差増幅信号Vfbは乗算器４５により電源電圧センサ９の信号出力である電源電圧フィードバック信号Vdetと乗算され、乗算器４５は交流電源電流の基準信号Iinを出力する。交流電源電流の基準信号Iinと電源電流センサ１０の信号出力である電源電流フィードバック信号Idetを抵抗器４６、４９コンデンサ４７、４８とオペアンプ５０により誤差増幅し電流誤差増幅信号Ifbを得る。Ifbが抵抗器５２、コンデンサ５３からなる発振器５１の鋸歯状波信号とＰＷＭ比較器５４により比較され、力率改善用ＩＣ１３のOut端子からＰＷＭ制御信号が出力される。すなわち、力率改善用ＩＣ１３はVinと直流基準電圧４１との誤差増幅作用によりVinと直流基準電圧４１とが同電圧になる状態で平滑コンデンサの充電電圧を電源電圧のピーク値よりも高い所定の電圧に保ち、またIinとIdetとの誤差増幅作用によりIinとVdetは比例しているため電源電流を電源電圧波形と相似になるようなＰＷＭ制御を行うようになっていた。
【０００４】
平滑コンデンサ電圧センサ１１は、例えばアナログフォトカプラ等の絶縁型の電圧信号伝達器により構成される。上記した力率改善用ＩＣの平滑コンデンサの充電電圧を一定に保つ機能により平滑コンデンサの充電電圧は平滑コンデンサ電圧センサ１１の出力信号Vinと直流基準電圧４１とが同電圧になるように制御されるが、アナログフォトカプラは入力電圧に対する出力電圧の特性が個々にばらつき、平滑コンデンサの充電電圧に対するVinの大きさが個々の平滑コンデンサ電圧センサ１１により異なるのでモータ運転時の平滑コンデンサの充電電圧も遠心機の機体によりばらつく。
【０００５】
【発明が解決しようとする課題】
従来の遠心分離機用モータの制御装置は、モータ整定運転及び低速回転領域での加速等のモータ負荷が小となりモータの印可電圧を低下させるため平滑コンデンサの充電電圧を低い電圧に調整する場合に、平滑コンデンサの充電電圧が遠心機機体固有のばらつきにより高くなるとモータ印可電圧が高くなりモータ巻線の磁気飽和による無効電力の増加のためモータ効率が低下し、一方、平滑コンデンサの充電電圧が低いとモータ印可電圧も低くなりモータトルクが不足するためモータ印可電圧の最適化が図れない問題があった。
【０００６】
本発明の目的は、上記問題を解消し、遠心機の運転時の平滑コンデンサの充電電圧の遠心機機体でのばらつきを排除し、モータの運転状態に従いモータ印可電圧の最適化を図るモータの制御装置を有する遠心分離機を提供することである。
【０００７】
【課題を解決するための手段】
上記目的は、交流電源を直流電源に変換し直流電源の電圧を制御する直流電力変換器と、直流電力変換器に接続され直流電源となる平滑コンデンサと、平滑コンデンサに接続されロータを回転駆動するモータの回転制御を行うモータ用双方向電力変換器と、交流電源から前記直流電力変換器への電力の供給をオン・オフする給電スイッチと、直流電力変換器を制御し平滑コンデンサの充電電圧を制御する制御回路と、制御回路に前記平滑コンデンサの充電電圧フィードバック信号を出力する平滑コンデンサ電圧センサと、平滑コンデンサの予め定められた所定の充電電圧を検出する直流電圧検出手段と、制御回路を制御する制御手段と、平滑コンデンサ電圧センサの出力電圧を把握する手段と、平滑コンデンサの充電電圧に対する平滑コンデンサ電圧センサの出力電圧の特性を記憶する記憶手段を設け、制御手段はモータ停止時に前記制御回路を制御し平滑コンデンサの充電電圧を調整し、直流電圧検出手段により平滑コンデンサの所定の充電電圧を検出し、平滑コンデンサの充電電圧に対する平滑コンデンサ電圧センサの出力電圧の特性を前記記憶手段に記憶し、モータの運転時は記憶手段に記憶された平滑コンデンサの充電電圧に対する平滑コンデンサ電圧センサの出力電圧の特性を基に制御回路を制御し、平滑コンデンサの充電電圧をモータの運転状況に従い調整することにより達成される。
【０００８】
【発明の実施の形態】
本発明の具体的実施例を以下図面に基づき詳細に説明する。図１は本発明の具体的実施例となる遠心機用モータの制御装置のブロック回路図であり、１は交流側をリアクトル２と給電スイッチ７を介して交流電源８に接続し直流側を平滑コンデンサ４に接続する環流整流回路に該環流整流回路を構成する夫々の整流素子に逆方向並列にＩＧＢＴ、ＦＥＴ等のスイッチング素子を接続した直流電力変換器となる電源用双方向電力変換器であり、３はロータ５を加速するための誘導モータ等のモータ６が力行運転する場合は平滑コンデンサ４の直流電源電力を交流電源電力に変換しモータ６を駆動し、ロータ５の減速によるモータ６が回生運転する場合は、回転するロータ５の力学的エネルギを帰還させるため、モータ６の交流電源電力を直流電源電力に変換し平滑コンデンサ４に回生電力を充電するモータ用双方向電力変換器（以下インバータと称す）である。１２は電源用双方向電力変換器１を制御し平滑コンデンサ４の充電電圧を制御する制御回路となる力率改善制御回路であり、力率改善制御回路１２の信号出力はフォトカプラ２１を駆動し電源用双方向電力変換器１のスイッチング素子１ｕ、１ｖ、１ｘ、１ｙをオン・オフする。力率改善制御回路１２の動作により電源用双方向電力変換器１は、モータ６が力行運転する場合はリアクトル２と協同して交流電源８の電圧波形に相似な電源電流が流れるよう昇圧コンバータとして動作し平滑コンデンサ４を電源電圧より高い電圧に充電する順方向運転を行い、一方、モータ６が回生運転する場合はリアクトル２と協同して電圧波形に相似な電源電流が流れるよう降圧コンバータとして逆方向運転を行い、平滑コンデンサ４の充電電圧が電源電圧より高い電圧で保持するように動作する。１０は交流電源８を流れる交流電源電流を力率改善制御回路１２にフィードバックするためのホールカレントセンサ等による電源電流センサ（以下Ｉセンサと称す）であり、９は絶縁トランス等により構成される電源電圧センサ（以下Ｖセンサと称す）であり、その信号出力である交流電源８の電源電圧フィードバック信号Vdetは力率改善制御回路１２内の力率改善用ＩＣ１３に入力される。１８は力率改善制御回路１２を制御する制御手段となるＣＰＵであり、２３は力率改善制御回路１２内で平滑コンデンサ電圧センサ１１（以下ＣＶセンサと称す）が出力する平滑コンデンサの充電電圧フィードバック信号の電圧を調整し平滑コンデンサの充電電圧を制御する例えばデジタル値を入力することでデジタル値に応じた分圧抵抗値の設定が行える、アナログ・デバイセズ（株）製AD8402のようなデジタルポテンショメータであり、２４は平滑コンデンサ電圧センサ１１の出力電圧を把握する手段となるＣＰＵ１８内蔵のＡ／Ｄ変換器である。ＣＶセンサ１１の信号出力はデジタルポテンショメータ２３とＡ／Ｄ変換器２４に入力され、ＣＰＵ１８はデジタルポテンショメータ２３の分圧抵抗比を設定するデジタル値をＰ１ポートから出力し、デジタルポテンショメータ２３はＣＶセンサ１１の信号出力を該デジタル値の入力に応じ分圧することで力率改善用ＩＣ１３への平滑コンデンサ電圧フィードバック信号の電圧を変更し平滑コンデンサ４の充電電圧を制御する。２２は平滑コンデンサのあらかじめ定められた所定の充電電圧を検出する直流電圧検出手段であり、その出力信号はＣＰＵ１８のＰ４ポートに入力される。２５は平滑コンデンサ４の充電電圧に対するＣＶセンサ１１の出力電圧の特性を記憶する記憶手段となるＥ²ＰＲＯＭ又はフラッシュメモリ等のＢＵＳを介しデータ書き換え可能な不揮発性メモリである。１７はアナログスイッチであり、上記した電源用双方向電力変換器１の順方向運転、逆方向運転が力率改善用ＩＣの同一の制御作用により行えるよう、Ｉセンサ１０の信号出力は、力率改善用ＩＣ１３へ入力される電源電流フィードバック信号Idetとして減衰器１６により信号の大きさの切換選択ができ、デジタルポテンショメータ２３の信号出力は、力率改善用ＩＣ１３へ入力される平滑コンデンサ電圧フィードバック信号Vinとして差動増幅器１５により基準電圧からの引算信号との切換選択が可能となるように設けてあり、ＣＰＵ１８のＰ２ポート出力により切換が行われる。１４は交流電源８の正・負のサイクル状態を検出し論理信号を出力する電源の正・負サイクル検出器であり、１９はＣＰＵ１８のＰ３ポート出力により電源正・負サイクル検出器１４の論理信号出力を基に電源用双方向電力変換器１のスイッチング素子１ｕ、１ｖ、１ｘ、１ｙのオン・オフパターンを切り換えるパターン切換器である。力率改善用ＩＣ１３はVdet信号、Vin信号、Idet信号がフィードバックされＰＷＭ制御信号を出力し、該ＰＷＭ制御信号は前記パターン切換器１９に入力され、パターン切換器１９は電源正・負サイクル及び順方向運転、逆方向運転時の前記スイッチング素子１ｕ、１ｖ、１ｘ、１ｙのオン・オフパターン信号を出力し、ゲートドライバ２０により該オン・オフパターン信号は増幅され力率改善制御回路１２の出力として電源用双方向電力変換器１の制御信号が出力される。
【０００９】
次に、上記した実施例の動作について、図２から図８を参照して説明する。なお図２から図８に於いては、図１と同一の機能の部分には同一の番号が付してある。図２は直流電圧検出手段２２の構成を示すブロック図である。図２に於いて、２６ｂは平滑コンデンサ４の陰極ライン、２６ａは同じく陽極ラインであり、ライン２６ａと２６ｂでいわゆるＤＣリンク電圧を形成し、３１は例えばナショナル・セミコンダクタ製パワーシャント型基準電圧ＬＭ４０４０等による高精度の基準電圧であり、抵抗３０を介し強電系電圧源２９に接続され平滑コンデンサ４の陰極ライン２６ｂを基準とした所定の電圧を出力するものである。基準電圧３１は抵抗３３を介しオペアンプ３４のプラス端子に入力され、オペアンプ３４のマイナス端子には抵抗３２を介し平滑コンデンサ４の充電電圧を抵抗２７、２８で分圧した電圧が入力される。フォトカプラ３５は強電系と制御系との絶縁を図るために設けてあり、フォトカプラ３５の発光ダイオードのアノード端子は抵抗３５を介し強電系電圧源２９に接続され、カソード端子はオペアンプ３４の出力端子に接続されており、フォトカプラ３５のトランジスタのエミッタ端子は制御系電源グランド３７に接続されコレクタ端子は抵抗３９を介し制御系電圧源３８に接続されている。抵抗２７、２８による平滑コンデンサ４の充電電圧を分圧した電圧が基準電圧３１より高くなるとオペアンプ３４の出力はＬＯＷレベルとなり、フォトカプラ３５の発光ダイオードに強電系電圧源２９より抵抗３５を介し電流が流れ、フォトカプラ３５のトランジスタがオンし直流電圧検出手段２２の出力であるフォトカプラ３５のトランジスタのコレクタ端子がＬＯＷレベルになる。従って、平滑コンデンサ４の充電電圧の抵抗２７、２８による分圧と基準電圧３１が同電圧となる平滑コンデンサ４の充電電圧を検出電圧とし、直流電圧検出手段２２は平滑コンデンサ４の充電電圧が検出電圧未満であればＨＩ論理を、検出電圧以上であればＬＯＷ論理をＣＰＵ１８のＰ４ポートに出力する。
【００１０】
本実施例では、インバータ３のスイッチング素子３ｕ、３ｖ、３ｗ、３ｘ、３ｙ、３ｚの制御用電源を図４のブロック回路図に示すような回路で構成しており、下アーム素子３ｘ、３ｙ、３ｚのスイッチング動作により下アーム素子のそれぞれにに対応する上アーム素子３ｕ、３ｖ、３ｗの電源をダイオード６１、６２、６３と電解コンデンサ６４、６５、６６によるチャージポンプ回路を構成し、例えば、下アーム素子３ｘがオンすることにより強電系電圧源２９からダイオード６１、電解コンデンサ６４、下アーム素子３ｘのルートを通してコンデンサ６４が充電され、下アーム素子３ｘのオフに従いコンデンサ６４の陰極側は強電系電圧源２９と基準電位を異にするフローティング状態となる。また、全ての下アーム素子３ｕ、３ｖ、３ｗのオフ時に平滑コンデンサ４の充電電圧が強電系電圧源２９の電圧より低い場合は、強電系電圧源２９からダイオード６１、電解コンデンサ６４、ブリッジ端子Ｕ、環流ダイオード６７、ライン２６a、平滑コンデンサ４、ライン２６ｂのルートをを通して平滑コンデンサ４を充電するため、給電スイッチ７がオフでインバータ３が動作していないモータ停止時の平滑コンデンサ４の充電電圧は強電系電圧源２９の電圧とほぼ等しくなる。
【００１１】
図５は本実施例に於ける電源用双方向電力変換器１の昇圧コンバータ動作時のデジタルポテンショメータ２３の分圧抵抗比デジタル値（以下Wpdataと称す）に対する平滑コンデンサ４の充電電圧（以下DCVと称す）の変化の様子を示したものである。平滑コンデンサ４の充電電圧DCVはＣＶセンサ１１の減衰率をα、力率改善用ＩＣ１３内の直流基準電圧４１をVref、Wpdataの上限値をWpmax、 WpdataがWpmaxである時のDCVをVLとすると、概略、以下の式で表され、
DCV＝（Vref ×Wpmax）÷（α×Wpdata）＋VL （１）
図５の実線に示したようにWpdataとDCVの間には反比例の関係がある。V1は直流電圧検出手段２２の平滑コンデンサ４の充電電圧の検出電圧であり、Wp1は平滑コンデンサ４の充電電圧が直流電圧検出手段２２の検出電圧V1となる時のデジタルポテンショメータ２３の分圧抵抗比デジタル値である。
【００１２】
図６は平滑コンデンサ４の充電電圧に対するＣＰＵ１８内蔵Ａ／Ｄ変換器２４のＡ／Ｄ変換値（以下DCVADと称す）の様子を示した図である。図６に於いて、AD0はモータの停止時に給電スイッチ７がオフで平滑コンデンサ４の充電電圧が強電系電圧源２９の電圧と同等である時のＡ／Ｄ変換値DCVADであり、AD1は平滑コンデンサ４の充電電圧が上記直流電圧検出手段２２の検出電圧Ｖ１となる時のＡ／Ｄ変換値DCVADであり、一点破線はAD0とAD 1の補問により求まる平滑コンデンサ４の充電電圧DCVに対するＡ／Ｄ変換器２４のＡ／Ｄ変換値DCVADの特性であり、 d(DCVAD)／d(DCV) は平滑コンデンサ４の充電電圧DCVに対するＡ／Ｄ変換器２４のＡ／Ｄ変換値DCVADの傾きであり、 AD2は平滑コンデンサ４の充電電圧が０Ｖの時のＡ／Ｄ変換値のオフセットである。VTはモータの運転状態で決まるモータ印可電圧をインバータ３が出力するための平滑コンデンサ４の制御電圧であり、ADTは平滑コンデンサ４の制御電圧VTでのＡ／Ｄ変換値DCVADである。ADTはd(DCVAD)／d(DCV)、VT、AD2を用い下式より求まる。
【００１３】
ADT＝ d(DCVAD)／d(DCV)×VT＋AD2 （２）
なお、ＣＶセンサ１１の平滑コンデンサ４の充電電圧に対する出力電圧特性が遠心機機体により異なるため、上記のAD0、AD1及び DCVに対するDCVADの特性、VTに対するADTの値も機体により異なるものとなる。
【００１４】
図７は本実施例におけるＣＰＵ１８がモータ停止時に力率改善制御回路１２及びデジタルポテンショメータ２３を制御して平滑コンデンサ４の充電電圧DCVを調整し、平滑コンデンサの所定の充電電圧を直流電圧検出手段２２により検出し、平滑コンデンサ４の充電電圧に対するＣＶセンサ１１の出力電圧の特性を記憶手段２５に記憶する処理のフローチャート図を示したものであり、ＣＰＵ１８内蔵のＲＯＭにあらかじめ定められた処理手順が記憶されてある。図７に於いて処理１０１はＰ０ポートにより給電スイッチ７をオフする処理であり、処理１０２は平滑コンデンサ４の電圧が強電系電圧源２９の電圧と同等になるように所定の時間インバータ３を例えば直流制動で駆動し平滑コンデンサ４を放電する処理であり、処理１０３に進みインバータ３の動作を止めて平滑コンデンサ４の充電電圧が強電系電圧源２９の電圧と同等である状態でのＣＶセンサ１１の出力電圧のＡ／Ｄ値AD0をサンプリングする。処理１０４はＰ０ポートにより給電スイッチ７をオンし平滑コンデンサ４を交流電源８のピーク電圧まで充電する処理であり、処理１０５はＰ１ポートよりデジタルポテンショメータ２３に分圧抵抗比デジタル値の上限値Wpmaxを出力する処理であり、処理１０６に進みＰ２、Ｐ３ポート出力により力行動作の力率改善制御を開始し、平滑コンデンサ４の充電電圧は図４に示したVLとなる。処理１０６は平滑コンデンサ４の充電電圧を高めるためのデジタルポテンショメータ２３の分圧抵抗比デジタル値Wpdataの−１減算処理であり、処理１０７は分圧抵抗比デジタル値WpdataをＰ１ポートよりデジタルポテンショメータ２３に出力することで平滑コンデンサ４の充電電圧を変更する処理であり、判断１０８に進みＰ４ポートの入力により平滑コンデンサ４の充電電圧DCVが直流電圧検出手段２２の検出電圧V1未満であり直流電圧検出手段２２の出力がＨＩ論理であれば処理１０６以降を繰り返し、DCVがV1以上となり直流電圧検出手段２２の出力がＬＯＷ論理であれば処理１０９に進みDCVがV1以上となった状態での平滑コンデンサ電圧センサ１１の出力電圧のＡ／Ｄ値AD1をサンプリングする。処理１１０は平滑コンデンサ電圧センサ１１の出力電圧のＡ／Ｄ値AD0とAD1の補問により平滑コンデンサ電圧センサ１１の入出力特性となる平滑コンデンサ４の充電電圧DCVに対するＡ／Ｄ変換器２４のＡ／Ｄ変換値DCVADの傾きd(DCVAD)／d(DCV)と平滑コンデンサ４の充電電圧が０Ｖの時のＡ／Ｄ変換値のオフセットAD2を計算する処理であり、処理１１１に進み上記のd(DCVAD)／d(DCV)と AD2を記憶手段２５に書き込む処理を実行する。
【００１５】
図８は本実施例に於けるＣＰＵ１８がモータ運転時の平滑コンデンサ４の充電電圧をモータの運転状態に従い調整する処理のフローチャート図を示したものであり、ＣＰＵ１８内蔵のＲＯＭにあらかじめ定められた処理手順が記憶されてある。図８に於いて処理２０１は記憶手段２５に記憶されたＣＶセンサ１１の入出力特性となる平滑コンデンサ４の充電電圧DCVに対するＡ／Ｄ変換器２４のＡ／Ｄ変換値DCVADの傾きd(DCVAD)／d(DCV)と平滑コンデンサ４の充電電圧が０Ｖの時のＡ／Ｄ変換値のオフセットAD2を読み出す処理であり、処理２０２に進み平滑コンデンサ４の充電電圧が制御電圧VTとなる時の目標Ａ／Ｄ変換値ADTを上記の（２）式より求める処理を行い、処理２０３に進みＰ０ポートにより給電スイッチ７をオンし平滑コンデンサ４を交流電源８のピーク電圧まで充電し、処理２０４に進み力率改善制御を開始する。処理２０５は平滑コンデンサ４の充電電圧DCVに対するＡ／Ｄ変換値DCVADをサンプリングし、判断２０６に進みＡ／Ｄ変換値の調整許容誤差をXとしDCVADがADT＋X以下であれば判断２０８に進み、 DCVADがADT＋Xを超えていれば処理２０７に進み、処理２０７で平滑コンデンサ４の充電電圧を低下させるためデジタルポテンショメータ２３の分圧抵抗比デジタル値Wpdataの＋１加算処理を行い処理２１０に進む。判断２０８はDCVADがADT−X以上であればDCVADが目標のADTの調整許容誤差以内となり平滑コンデンサ４の充電電圧DCVの制御電圧VTへの電圧調整が完了し処理を終え、DCVADがADT−X未満であれば処理２０９に進み、処理２０９で平滑コンデンサ４の充電電圧を高めるためデジタルポテンショメータ２３の分圧抵抗比デジタル値Wpdataの−１減算処理を行い、処理２１０に進み分圧抵抗比デジタル値WpdataをＰ１ポートよりデジタルポテンショメータ２３に出力することで平滑コンデンサ４の充電電圧を変更する処理を行い、DCVADが目標のADTの調整許容誤差以内となるまで処理２０５以降を繰り返す。
【００１６】
従って、ＣＰＵ１８は、モータ停止時にデジタルポテンショメータ２３を制御して平滑コンデンサ４の充電電圧DCVを直流電圧検出手段２２の検出電圧であるV1に調整し、平滑コンデンサ４の充電電圧に対するＣＶセンサ１１の出力電圧の特性となる平滑コンデンサ４の充電電圧DCVに対するＡ／Ｄ変換値DCVADの傾きd(DCVAD)／d(DCV)と平滑コンデンサ４の充電電圧が０Ｖの時のＡ／Ｄ変換値のオフセットAD2を記憶手段２５に記憶することで遠心機機体固有のＣＶセンサ１１の入出力特性を把握し、モータ運転時は記憶手段２５に記憶されたd(DCVAD)／d(DCV)とAD2を読み出しこれを基に平滑コンデンサ４の充電電圧がモータの運転状態であらかじめ決められた所定の制御電圧になるようにデジタルポテンショメータ２３を制御するので、モータの運転状態に従い遠心機の機体によらず平滑コンデンサ４の充電電圧を所定の電圧に調整しモータ印可電圧の最適化を図ることができる。
【００１７】
なお、遠心分離機の機体固有のＣＶセンサ１１の入出力特性を把握するための平滑コンデンサ４の充電電圧の直流電圧検出手段２２の検出電圧の調整及び平滑コンデンサ４の充電電圧に対するＣＶセンサ１１の出力電圧の特性の記憶はモータ停止時に行うと説明したが、モータを運転する前の例えば工場出荷時に一度だけ行い、モータを運転する直前に記憶手段２５より平滑コンデンサ４の充電電圧DCVに対するＡ／Ｄ変換値DCVADの傾きd(DCVAD)／d(DCV)とオフセットAD2を読み出し、モータの運転時にモータの運転状況に従いデジタルポテンショメータ２３を制御して平滑コンデンサ４の充電電圧を調整することによっても本発明の目的は達成できる。
【００１８】
また、本実施例では記憶手段２５に記憶するＣＶセンサ１１の入出力特性は上記のAD0とAD1の補問により求めた傾きd(DCVAD)／d(DCV)とオフセットAD2であったが、モータ停止時にAD0、AD1を記憶し、モータ運転時に平滑コンデンサ４の充電電圧が制御電圧VTとなる時の目標Ａ／Ｄ変換値ADTをAD0、AD1の補問より求めても良い。
【００１９】
本実施例においては、直流電力変換器として電源用双方向電力変換器１を、直流電力変換器を制御し平滑コンデンサの充電電圧を制御する制御回路は力率改善制御回路１２を用いた例を挙げ説明したが、平滑コンデンサ４の充電電圧を位相制御により変更するサイリスタ、トライアック等の自己消孤機能の持つデバイスにより構成される直流電力変換器とその制御回路を用いた場合に於いても同様の効果を得ることができる。
【００２０】
また、本実施例のように直流電力変換器として電源用双方向電力変換器１を、直流電力変換器を制御し平滑コンデンサの充電電圧を制御する制御回路として力率改善制御回路１２を用いることにより交流電源電流の高調波成分を抑制し電源力率を向上させる機能を持つ装置では、個々のＣＶセンサ１１の入出力特性のばらつきにより平滑コンデンサ４の充電電圧が電源電圧のピーク値に対し十分高くない場合に、モータの力行、回生運転時とも電源用双方向電力変換器の昇圧、降圧コンバータ動作による電源電流の高力率化動作が電源電圧のピーク近傍で行われず、電源電圧のピーク近傍で電源電流が歪み交流電源電流の力率が低下する欠点があったが、本実施例に於けるＣＶセンサ１１の入出力特性の把握及び本特性を基にした平滑コンデンサの充電電圧の調整を行うと、モータの力行・回生運転時とも遠心機の機体によらず平滑コンデンサ４の充電電圧を電源電圧のピーク値より十分高い電圧に保つことができるため、電源電流の力率を一定の高い値とすることが可能となる。
【００２１】
【発明の効果】
本発明によれば、遠心機機体固有の平滑コンデンサ電圧センサの入出力特性の把握することで遠心分離機の運転時の平滑コンデンサの充電電圧の製品ばらつきを排除し、モータの運転状態に従いモータ印可電圧の最適化を図ることができる。
【図面の簡単な説明】
【図１】本発明になる遠心分離機用モータの制御装置の具体的実施例を示すブロック回路図である。
【図２】図１の詳細な実施例を示すブロック回路図である。
【図３】力率改善用ＩＣ１３のブロック機能図である。
【図４】図１の詳細な実施例を示すブロック回路図である。
【図５】電源用双方向電力変換器の昇圧コンバータ動作時のデジタルポテンショメータの分圧抵抗比デジタル値に対する平滑コンデンサ４の充電電圧の変化の様子を示した図である。
【図６】平滑コンデンサの充電電圧に対するＣＰＵ内蔵Ａ／Ｄ変換器のＡ／Ｄ変換値の様子を示した図である。
【図７】ＣＰＵがモータ停止時に力率改善制御回路及びデジタルポテンショメータを制御して平滑コンデンサの充電電圧を調整し、平滑コンデンサの所定の充電電圧を直流電圧検出手段により検出し、平滑コンデンサの充電電圧に対する平滑コンデンサ電圧センサの出力電圧の特性を記憶手段に記憶する処理のフローチャートを示した図である。
【図８】ＣＰＵがモータ運転時の平滑コンデンサの充電電圧をモータの運転状態に従い調整する処理のフローチャートを示した図である。
【符号の説明】
１は直流電力変換器、３はモータ用双方向電力変換器、４は平滑コンデンサ、７は給電スイッチ、１１は平滑コンデンサ４の充電電圧をフィードバックする平滑コンデンサ電圧センサ、１２は平滑コンデンサの充電電圧を制御する制御回路、１８はＣＰＵ、２２は平滑コンデンサのあらかじめ定められた所定の充電電圧を検出する直流電圧検出手段、２３はデジタルポテンショメータ、２４は平滑コンデンサ電圧センサの出力電圧を把握する手段、２５は平滑コンデンサの充電電圧に対する平滑コンデンサ電圧センサの出力電圧の特性を記憶する記憶手段である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to calibration of a smoothing capacitor voltage sensor that measures a so-called DC link voltage in a control device for a motor that drives a centrifuge rotor, particularly an inverter control device.
[0002]
[Prior art]
As described in JP-A-7-246351, a conventional control device for a centrifuge motor is a power bidirectional power converter in which an AC side is connected to an AC power source via a reactor and a DC side is connected to a smoothing capacitor. In addition, a motor bidirectional power converter is connected to the motor on the AC side and connected to the smoothing capacitor on the DC side. During powering and power regeneration operation of the motor, the power supply voltage waveform and smoothing capacitor are used in the power factor correction control circuit. Feedback of voltage and power supply current waveform, power factor improvement IC Et Based on the PWM control signal that is output, the switching element of the bidirectional power converter for power supply is turned on and off, and the motor charging power for driving the centrifuge rotor is accelerated. In order to maintain the voltage higher than the value, the reactor and the bidirectional power converter for power supply operate as a step-up converter, and during motor power regeneration to decelerate the rotor, the charging voltage of the smoothing capacitor is the peak value of the power supply voltage. By operating the reactor and the bidirectional power converter for power supply as a step-down converter while adjusting the voltage to a higher voltage, the AC power supply current was power-run and the harmonic current was reduced at a high power factor both during regeneration.
[0003]
The operation of the power factor correction IC 13 will be described with reference to the block diagram of the power factor improvement IC in FIG. 3. The DC reference voltage 41 and the smoothing capacitor charging voltage feedback signal Vin output from the smoothing capacitor voltage sensor 11 are expressed as follows. The resistors 40 and 42, the filter capacitor 43, and the operational amplifier 44 are used for error amplification to obtain a voltage error amplified signal Vfb. The voltage error amplification signal Vfb is multiplied by a power supply voltage feedback signal Vdet which is a signal output of the power supply voltage sensor 9 by a multiplier 45, and the multiplier 45 outputs a reference signal Iin of an AC power supply current. The AC power supply current reference signal Iin and the power supply current feedback signal Idet which is the signal output of the power supply current sensor 10 are error-amplified by the resistors 46, 49 capacitors 47 and 48 and the operational amplifier 50 to obtain a current error amplification signal Ifb. Ifb is compared with the sawtooth wave signal of the oscillator 51 including the resistor 52 and the capacitor 53 by the PWM comparator 54, and the PWM control signal is output from the Out terminal of the power factor improving IC 13. That is, the power factor improving IC 13 sets the charging voltage of the smoothing capacitor to a predetermined value higher than the peak value of the power supply voltage in a state where Vin and the DC reference voltage 41 become the same voltage due to the error amplification effect of Vin and the DC reference voltage 41. Since the voltage is maintained and Iin and Vdet are proportional to each other by the error amplification effect between Iin and Idet, PWM control is performed so that the power supply current is similar to the power supply voltage waveform.
[0004]
The smoothing capacitor voltage sensor 11 is configured by an insulating voltage signal transmitter such as an analog photocoupler. The smoothing capacitor charging voltage is controlled so that the output voltage Vin of the smoothing capacitor voltage sensor 11 and the DC reference voltage 41 become the same voltage by the function of keeping the charging voltage of the smoothing capacitor of the power factor improving IC constant. However, since the characteristics of the output voltage with respect to the input voltage of the analog photocoupler vary individually, and the magnitude of Vin with respect to the charging voltage of the smoothing capacitor varies depending on the individual smoothing capacitor voltage sensor 11, the charging voltage of the smoothing capacitor during motor operation is also centrifugal. It varies depending on the aircraft.
[0005]
[Problems to be solved by the invention]
The conventional centrifuge motor control device is used when the charging voltage of the smoothing capacitor is adjusted to a low voltage in order to reduce the motor load such as motor settling operation and acceleration in the low-speed rotation region and reduce the applied voltage of the motor. When the charging voltage of the smoothing capacitor increases due to the inherent variation of the centrifuge body, the motor applied voltage increases and the motor efficiency decreases due to an increase in reactive power due to magnetic saturation of the motor windings, while the charging voltage of the smoothing capacitor is low As a result, the motor applied voltage is lowered and the motor torque is insufficient, so that the motor applied voltage cannot be optimized.
[0006]
An object of the present invention is to control a motor that solves the above problems, eliminates variation in the charging voltage of the smoothing capacitor during the operation of the centrifuge, and optimizes the motor applied voltage according to the operating state of the motor. apparatus Centrifuge with Is to provide.
[0007]
[Means for Solving the Problems]
The purpose is to convert an AC power source into a DC power source to control the voltage of the DC power source, a smoothing capacitor connected to the DC power converter to serve as a DC power source, and a rotor connected to the smoothing capacitor to rotate the rotor. A bidirectional power converter for the motor that controls the rotation of the motor, a power supply switch that turns on / off the power supply from the AC power source to the DC power converter, and the charging voltage of the smoothing capacitor by controlling the DC power converter A control circuit for controlling, a smoothing capacitor voltage sensor for outputting a charging voltage feedback signal of the smoothing capacitor to the control circuit, a DC voltage detecting means for detecting a predetermined charging voltage predetermined for the smoothing capacitor, and a control circuit. Control means, means for grasping the output voltage of the smoothing capacitor voltage sensor, and a smoothing capacitor for the charging voltage of the smoothing capacitor. Storage means for storing the characteristics of the output voltage of the voltage sensor, the control means controls the control circuit when the motor is stopped to adjust the charging voltage of the smoothing capacitor, and the DC voltage detecting means sets the predetermined charging voltage of the smoothing capacitor. Detecting and storing the characteristic of the output voltage of the smoothing capacitor voltage sensor with respect to the charging voltage of the smoothing capacitor in the storage means, and during operation of the motor, the output voltage of the smoothing capacitor voltage sensor with respect to the charging voltage of the smoothing capacitor stored in the storage means This is achieved by controlling the control circuit based on the above characteristics and adjusting the charging voltage of the smoothing capacitor in accordance with the operating condition of the motor.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Specific embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block circuit diagram of a centrifuge motor control apparatus according to a specific embodiment of the present invention. Reference numeral 1 denotes an AC side connected to an AC power supply 8 via a reactor 2 and a power supply switch 7 and a DC side is smoothed. A bidirectional power converter for a power source that is a DC power converter in which a switching element such as an IGBT or FET is connected in reverse parallel to each rectifying element constituting the circulating rectifier circuit to the circulating rectifier circuit connected to the capacitor 4 3, when a motor 6 such as an induction motor for accelerating the rotor 5 performs a power running operation, the DC power of the smoothing capacitor 4 is converted into AC power and the motor 6 is driven. When performing regenerative operation, in order to feed back the mechanical energy of the rotating rotor 5, the motor 6 converts the AC power supply power to DC power supply power and charges the smoothing capacitor 4 with the regenerative power. Use a two-way power converter (hereinafter referred to as inverter). Reference numeral 12 denotes a power factor correction control circuit that is a control circuit that controls the bidirectional power converter 1 for power supply and controls the charging voltage of the smoothing capacitor 4. The signal output of the power factor correction control circuit 12 drives the photocoupler 21. The switching elements 1u, 1v, 1x, 1y of the bidirectional power converter 1 for power supply are turned on / off. By the operation of the power factor correction control circuit 12, the bidirectional power converter 1 for power supply functions as a boost converter so that a power supply current similar to the voltage waveform of the AC power supply 8 flows in cooperation with the reactor 2 when the motor 6 is in a power running operation. Operates and performs forward operation to charge the smoothing capacitor 4 to a voltage higher than the power supply voltage. On the other hand, when the motor 6 performs regenerative operation, it works as a step-down converter in cooperation with the reactor 2 so that a power supply current similar to the voltage waveform flows. The direction operation is performed and the charging voltage of the smoothing capacitor 4 is maintained at a voltage higher than the power supply voltage. Reference numeral 10 denotes a power source current sensor (hereinafter referred to as I sensor) such as a hall current sensor for feeding back the AC power source current flowing through the AC power source 8 to the power factor correction control circuit 12, and 9 denotes a power source constituted by an insulating transformer or the like. A power supply voltage feedback signal Vdet of the AC power supply 8, which is a voltage sensor (hereinafter referred to as V sensor), is input to the power factor correction IC 13 in the power factor correction control circuit 12. Reference numeral 18 denotes a CPU as control means for controlling the power factor correction control circuit 12, and reference numeral 23 denotes a smoothing capacitor charging voltage feedback output from the smoothing capacitor voltage sensor 11 (hereinafter referred to as CV sensor) in the power factor improvement control circuit 12. Adjust the signal voltage and control the charging voltage of the smoothing capacitor. For example, a digital potentiometer such as AD8402 manufactured by Analog Devices can be used to set the voltage dividing resistance value according to the digital value by inputting a digital value. Reference numeral 24 denotes an A / D converter built in the CPU 18 which is a means for grasping the output voltage of the smoothing capacitor voltage sensor 11. The signal output of the CV sensor 11 is input to the digital potentiometer 23 and the A / D converter 24. The CPU 18 outputs a digital value for setting the voltage dividing resistance ratio of the digital potentiometer 23 from the P1 port. Is divided according to the input of the digital value to change the voltage of the smoothing capacitor voltage feedback signal to the power factor improving IC 13 and control the charging voltage of the smoothing capacitor 4. Reference numeral 22 denotes DC voltage detecting means for detecting a predetermined charging voltage determined in advance for the smoothing capacitor, and its output signal is inputted to the P4 port of the CPU 18. E is a storage means for storing the characteristics of the output voltage of the CV sensor 11 with respect to the charging voltage of the smoothing capacitor 4. ² This is a nonvolatile memory in which data can be rewritten via BUS such as PROM or flash memory. Reference numeral 17 denotes an analog switch. The signal output of the I sensor 10 is a power factor so that the forward operation and the reverse operation of the bidirectional power converter 1 for power supply can be performed by the same control action of the power factor improvement IC. The magnitude of the signal can be switched by the attenuator 16 as the power supply current feedback signal Idet input to the improvement IC 13, and the signal output of the digital potentiometer 23 is the smoothing capacitor voltage feedback signal Vin input to the power factor improvement IC 13. As described above, the differential amplifier 15 is provided so that it can be switched to and from the subtraction signal from the reference voltage, and switching is performed by the P2 port output of the CPU 18. Reference numeral 14 denotes a power supply positive / negative cycle detector that detects a positive / negative cycle state of the AC power supply 8 and outputs a logic signal. Reference numeral 19 denotes a logic signal of the power supply positive / negative cycle detector 14 based on the P3 port output of the CPU 18. This is a pattern changer that switches on / off patterns of switching elements 1u, 1v, 1x, and 1y of the bidirectional power converter 1 for power supply based on the output. The power factor improving IC 13 feeds back the Vdet signal, the Vin signal, and the Idet signal and outputs a PWM control signal. The PWM control signal is input to the pattern switch 19. The on / off pattern signals of the switching elements 1u, 1v, 1x, and 1y during the direction operation and the reverse direction operation are output, and the on / off pattern signal is amplified by the gate driver 20 as the output of the power factor correction control circuit 12. A control signal for the power bidirectional power converter 1 is output.
[0009]
Next, the operation of the above-described embodiment will be described with reference to FIGS. 2 to 8, the same reference numerals are given to the same functional parts as those in FIG. 1. FIG. 2 is a block diagram showing the configuration of the DC voltage detection means 22. In FIG. 2, 26b is a cathode line of the smoothing capacitor 4, 26a is also an anode line, lines 26a and 26b form a so-called DC link voltage, and 31 is a power shunt type reference voltage LM4040 made by National Semiconductor, for example. Is a high-accuracy reference voltage that is connected to a high voltage source 29 via a resistor 30 and outputs a predetermined voltage based on the cathode line 26b of the smoothing capacitor 4. The reference voltage 31 is input to the positive terminal of the operational amplifier 34 via the resistor 33, and the voltage obtained by dividing the charging voltage of the smoothing capacitor 4 by the resistors 27 and 28 is input to the negative terminal of the operational amplifier 34 via the resistor 32. The photocoupler 35 is provided to insulate the high voltage system from the control system. The anode terminal of the light emitting diode of the photocoupler 35 is connected to the high voltage system voltage source 29 via the resistor 35, and the cathode terminal is the output of the operational amplifier 34. The emitter terminal of the transistor of the photocoupler 35 is connected to the control system power supply ground 37, and the collector terminal is connected to the control system voltage source 38 via the resistor 39. When the voltage obtained by dividing the charging voltage of the smoothing capacitor 4 by the resistors 27 and 28 becomes higher than the reference voltage 31, the output of the operational amplifier 34 becomes the LOW level, and the light emitting diode of the photocoupler 35 is supplied with current from the high voltage source 29 through the resistor 35. Flows, the transistor of the photocoupler 35 is turned on, and the collector terminal of the transistor of the photocoupler 35, which is the output of the DC voltage detecting means 22, becomes the LOW level. Therefore, the voltage divided by the resistors 27 and 28 of the charging voltage of the smoothing capacitor 4 and the charging voltage of the smoothing capacitor 4 where the reference voltage 31 is the same voltage are used as the detection voltage, and the DC voltage detecting means 22 detects the charging voltage of the smoothing capacitor 4. Less than voltage If If HI logic exceeds the detection voltage If The LOW logic is output to the P4 port of the CPU 18.
[0010]
In the present embodiment, the control power supply for the switching elements 3u, 3v, 3w, 3x, 3y, and 3z of the inverter 3 is configured by a circuit as shown in the block circuit diagram of FIG. 4, and the lower arm elements 3x, 3y, The power supply of the upper arm elements 3u, 3v, and 3w corresponding to each of the lower arm elements is configured by a diode pump 61, 62, 63 and electrolytic capacitors 64, 65, 66 by the switching operation of 3z, for example, When the arm element 3x is turned on, the capacitor 64 is charged from the strong voltage source 29 through the route of the diode 61, the electrolytic capacitor 64, and the lower arm element 3x, and the cathode side of the capacitor 64 is connected to the strong voltage by the lower arm element 3x being turned off. A floating state is set in which the reference potential is different from that of the source 29. Further, when the charging voltage of the smoothing capacitor 4 is lower than the voltage of the high voltage system voltage source 29 when all the lower arm elements 3u, 3v, 3w are turned off, the high voltage system voltage source 29 to the diode 61, the electrolytic capacitor 64, the bridge terminal U In order to charge the smoothing capacitor 4 through the route of the freewheeling diode 67, the line 26a, the smoothing capacitor 4, and the line 26b, the charging voltage of the smoothing capacitor 4 when the motor is stopped when the power supply switch 7 is off and the inverter 3 is not operating is It becomes substantially equal to the voltage of the high voltage system voltage source 29.
[0011]
FIG. 5 shows the charging voltage (hereinafter referred to as DCV) of the smoothing capacitor 4 with respect to the digital value of the voltage dividing resistance ratio (hereinafter referred to as Wpdata) of the digital potentiometer 23 during the operation of the boost converter of the bidirectional power converter 1 for power supply in this embodiment. This shows the state of change. The charging voltage DCV of the smoothing capacitor 4 is assumed that the attenuation factor of the CV sensor 11 is α, the DC reference voltage 41 in the power factor correction IC 13 is Vref, the upper limit value of Wpdata is Wpmax, and the DCV when Wpdata is Wpmax is VL. , Roughly represented by the following formula:
DCV = (Vref x Wpmax) / (α x Wpdata) + VL (1)
As shown by the solid line in FIG. 5, there is an inversely proportional relationship between Wpdata and DCV. V1 is a detection voltage of the charging voltage of the smoothing capacitor 4 of the DC voltage detection means 22, and Wp1 is a voltage dividing resistance ratio of the digital potentiometer 23 when the charging voltage of the smoothing capacitor 4 becomes the detection voltage V1 of the DC voltage detection means 22. It is a digital value.
[0012]
FIG. 6 is a diagram showing the state of the A / D conversion value (hereinafter referred to as DCVAD) of the A / D converter 24 built in the CPU 18 with respect to the charging voltage of the smoothing capacitor 4. In FIG. 6, AD0 is an A / D conversion value DCVAD when the power supply switch 7 is turned off when the motor is stopped and the charging voltage of the smoothing capacitor 4 is equal to the voltage of the high voltage system voltage source 29, and AD1 is smoothing. The A / D conversion value DCVAD when the charging voltage of the capacitor 4 becomes the detection voltage V1 of the DC voltage detecting means 22, and the one-dot broken line is A with respect to the charging voltage DCV of the smoothing capacitor 4 obtained by the supplement of AD0 and AD1. D (DCVAD) / d (DCV) is a slope of the A / D conversion value DCVAD of the A / D converter 24 with respect to the charging voltage DCV of the smoothing capacitor 4. AD2 is an offset of the A / D conversion value when the charging voltage of the smoothing capacitor 4 is 0V. VT is a control voltage of the smoothing capacitor 4 for the inverter 3 to output a motor applied voltage determined by the operating state of the motor, and ADT is an A / D conversion value DCVAD at the control voltage VT of the smoothing capacitor 4. ADT is obtained from the following equation using d (DCVAD) / d (DCV), VT, and AD2.
[0013]
ADT = d (DCVAD) / d (DCV) x VT + AD2 (2)
In addition, since the output voltage characteristic with respect to the charging voltage of the smoothing capacitor 4 of the CV sensor 11 is different depending on the centrifuge body, the above-mentioned characteristics of DCVAD with respect to AD0, AD1, and DCV, and the value of ADT with respect to VT also differ depending on the body.
[0014]
In FIG. 7, the CPU 18 in this embodiment controls the power factor correction control circuit 12 and the digital potentiometer 23 when the motor is stopped to adjust the charging voltage DCV of the smoothing capacitor 4. FIG. 4 is a flowchart showing a process of storing in the storage means 25 the characteristics of the output voltage of the CV sensor 11 with respect to the charging voltage of the smoothing capacitor 4, and a predetermined processing procedure is stored in the ROM built in the CPU 18. It has been done. In FIG. 7, a process 101 is a process of turning off the power supply switch 7 by the P0 port, and a process 102 is performed for a predetermined time, for example, by switching the inverter 3 so that the voltage of the smoothing capacitor 4 becomes equal to the voltage of the high voltage system voltage source 29. This is a process of driving by DC braking and discharging the smoothing capacitor 4. The process proceeds to process 103, the operation of the inverter 3 is stopped, and the charging voltage of the smoothing capacitor 4 is equal to the voltage of the high voltage system voltage source 29. The A / D value AD0 of the output voltage is sampled. The process 104 is a process for turning on the power supply switch 7 by the P0 port and charging the smoothing capacitor 4 to the peak voltage of the AC power supply 8. The process 105 is to set the upper limit value Wpmax of the digital resistance ratio digital value to the digital potentiometer 23 from the P1 port. The process proceeds to process 106, and the power factor correction control of the power running operation is started by the P2 and P3 port outputs, and the charging voltage of the smoothing capacitor 4 becomes VL shown in FIG. processing 106 Is a -1 subtraction process of the voltage dividing resistance ratio digital value Wpdata of the digital potentiometer 23 for increasing the charging voltage of the smoothing capacitor 4. 107 Is a process for changing the charging voltage of the smoothing capacitor 4 by outputting the digital resistance ratio digital value Wpdata from the P1 port to the digital potentiometer 23. 108 If the charging voltage DCV of the smoothing capacitor 4 is less than the detection voltage V1 of the DC voltage detecting means 22 and the output of the DC voltage detecting means 22 is HI logic by the input of the P4 port, the processing is performed. 106 After that, if DCV becomes V1 or more and the output of the DC voltage detection means 22 is LOW logic, processing 109 Then, the A / D value AD1 of the output voltage of the smoothing capacitor voltage sensor 11 in a state where DCV is equal to or higher than V1 is sampled. processing 110 Is the A / D value of the A / D converter 24 for the charging voltage DCV of the smoothing capacitor 4 which becomes the input / output characteristic of the smoothing capacitor voltage sensor 11 by interpolating the A / D values AD0 and AD1 of the output voltage of the smoothing capacitor voltage sensor 11. This is a process for calculating the slope d (DCVAD) / d (DCV) of the conversion value DCVAD and the offset AD2 of the A / D conversion value when the charging voltage of the smoothing capacitor 4 is 0V. 111 Then, the process of writing d (DCVAD) / d (DCV) and AD2 in the storage means 25 is executed.
[0015]
FIG. 8 shows a flowchart of the process in which the CPU 18 according to this embodiment adjusts the charging voltage of the smoothing capacitor 4 during motor operation according to the motor operating state. The process predetermined in the ROM built in the CPU 18 is shown in FIG. The procedure is stored. Figure 8 In the process 201, the slope d (DCVAD) / of the A / D conversion value DCVAD of the A / D converter 24 with respect to the charging voltage DCV of the smoothing capacitor 4 which is the input / output characteristic of the CV sensor 11 stored in the storage means 25. d (DCV) and A / D conversion value offset AD2 when the charging voltage of the smoothing capacitor 4 is 0 V. The process proceeds to processing 202 and the target A when the charging voltage of the smoothing capacitor 4 becomes the control voltage VT. / D conversion value ADT is obtained from the above equation (2), the process proceeds to process 203, the power supply switch 7 is turned on by the P0 port, the smoothing capacitor 4 is charged to the peak voltage of the AC power supply 8, and the process proceeds to process 204. Start rate improvement control. The process 205 samples the A / D conversion value DCVAD with respect to the charging voltage DCV of the smoothing capacitor 4, proceeds to decision 206, sets the A / D conversion value adjustment allowable error to X, and proceeds to decision 208 if DCVAD is ADT + X or less. If ADT + X exceeds ADT + X, the process proceeds to process 207. In process 207, the voltage dividing resistance ratio digital value Wpdata of the digital potentiometer 23 is incremented by 1 to decrease the charging voltage of the smoothing capacitor 4, and the process proceeds to process 210. Decision 208 is if DCVAD is greater than or equal to ADT-X DCVAD Is within the adjustment tolerance of the target ADT, the voltage adjustment to the control voltage VT of the charging voltage DCV of the smoothing capacitor 4 is completed, and the process is completed. If DCVAD is less than ADT-X, the process proceeds to process 209 and smoothed by process 209 In order to increase the charging voltage of the capacitor 4, −1 subtraction processing is performed on the digital resistance ratio digital value Wpdata of the digital potentiometer 23, and the process proceeds to processing 210 to output the digital resistance ratio digital value Wpdata from the P1 port to the digital potentiometer 23. A process for changing the charging voltage of the smoothing capacitor 4 is performed. DCVAD Until the target ADT is within the adjustment tolerance of the target ADT.
[0016]
Therefore, the CPU 18 controls the digital potentiometer 23 when the motor is stopped to adjust the charging voltage DCV of the smoothing capacitor 4 to V1, which is the detection voltage of the DC voltage detecting means 22, and the output of the CV sensor 11 with respect to the charging voltage of the smoothing capacitor 4. The slope d (DCVAD) / d (DCV) of the A / D conversion value DCVAD with respect to the charging voltage DCV of the smoothing capacitor 4, which is the voltage characteristic, and the offset AD2 of the A / D conversion value when the charging voltage of the smoothing capacitor 4 is 0V Is stored in the storage means 25 to grasp the input / output characteristics of the CV sensor 11 unique to the centrifuge body, and d (DCVAD) / d (DCV) and AD2 stored in the storage means 25 are read out during motor operation. Based on the above, the charging voltage of the smoothing capacitor 4 is determined in advance by the operating state of the motor. System of Since the digital potentiometer 23 is controlled so as to have a control voltage, the charging voltage of the smoothing capacitor 4 can be adjusted to a predetermined voltage according to the operating state of the motor, regardless of the body of the centrifuge, and the motor applied voltage can be optimized. .
[0017]
It should be noted that the adjustment of the detection voltage of the DC voltage detection means 22 of the charging voltage of the smoothing capacitor 4 and the charging voltage of the smoothing capacitor 4 of the CV sensor 11 to grasp the input / output characteristics of the CV sensor 11 unique to the body of the centrifuge. It has been described that the output voltage characteristic is stored when the motor is stopped. However, the output voltage characteristic is stored only once at the time of shipment from the factory, for example, before the motor is operated, and immediately before the motor is operated, the storage unit 25 stores the A / V with respect to the charging voltage DCV of the smoothing capacitor 4. It is also possible to read the slope d (DCVAD) / d (DCV) of the D-converted value DCVAD and the offset AD2 and adjust the charging voltage of the smoothing capacitor 4 by controlling the digital potentiometer 23 according to the motor operating condition during motor operation. The object of the invention can be achieved.
[0018]
In the present embodiment, the input / output characteristics of the CV sensor 11 stored in the storage means 25 are the slope d (DCVAD) / d (DCV) and the offset AD2 obtained by the above-mentioned interpolating AD0 and AD1, but the motor AD0 and AD1 may be stored when the motor is stopped, and the target A / D conversion value ADT when the charging voltage of the smoothing capacitor 4 becomes the control voltage VT during motor operation may be obtained from the AD0 and AD1 supplements.
[0019]
In the present embodiment, the bidirectional power converter 1 for power supply is used as a DC power converter, and the control circuit for controlling the DC power converter and the charging voltage of the smoothing capacitor is an example using a power factor correction control circuit 12. As described above, the same applies to the case where a DC power converter constituted by a device having a self-extinguishing function such as a thyristor or a triac that changes the charging voltage of the smoothing capacitor 4 by phase control and its control circuit are used. The effect of can be obtained.
[0020]
Further, as in this embodiment, the power bidirectional power converter 1 is used as a DC power converter, and the power factor correction control circuit 12 is used as a control circuit for controlling the DC power converter and controlling the charging voltage of the smoothing capacitor. In the device having the function of suppressing the harmonic component of the AC power supply current and improving the power supply power factor, the charging voltage of the smoothing capacitor 4 is sufficient with respect to the peak value of the power supply voltage due to variations in the input / output characteristics of the individual CV sensors 11. When the power is not high, the power supply current boosting and step-down converter operations are not performed near the peak of the power supply voltage, but near the peak of the power supply voltage. However, the power source current is distorted and the power factor of the AC power source current is reduced. However, the input / output characteristics of the CV sensor 11 in this embodiment are grasped and the smoothing capacitor based on the characteristics is used. When the charging voltage of the motor is adjusted, the charging voltage of the smoothing capacitor 4 can be maintained at a voltage sufficiently higher than the peak value of the power supply voltage regardless of the centrifuge body during powering and regenerative operation of the motor. The power factor can be set to a constant high value.
[0021]
【The invention's effect】
According to the present invention, by grasping the input / output characteristics of the smoothing capacitor voltage sensor unique to the centrifuge body, product variations in the charging voltage of the smoothing capacitor during operation of the centrifuge are eliminated, and the motor application is performed according to the motor operating state. The voltage can be optimized.
[Brief description of the drawings]
FIG. 1 is a block circuit diagram showing a specific embodiment of a control device for a centrifuge motor according to the present invention.
FIG. 2 is a block circuit diagram showing a detailed embodiment of FIG. 1;
FIG. 3 is a block functional diagram of a power factor improving IC 13;
FIG. 4 is a block circuit diagram showing a detailed embodiment of FIG. 1;
FIG. 5 is a diagram showing a change in the charging voltage of the smoothing capacitor 4 with respect to the digital value of the voltage dividing resistance ratio of the digital potentiometer during the boost converter operation of the bidirectional power converter for power supply.
FIG. 6 is a diagram showing a state of an A / D conversion value of a CPU built-in A / D converter with respect to a charging voltage of a smoothing capacitor.
FIG. 7 shows the control of the power factor correction control circuit and the digital potentiometer when the motor is stopped, adjusting the charging voltage of the smoothing capacitor, detecting the predetermined charging voltage of the smoothing capacitor by the DC voltage detecting means, and charging the smoothing capacitor. It is the figure which showed the flowchart of the process which memorize | stores the characteristic of the output voltage of the smoothing capacitor voltage sensor with respect to a voltage in a memory | storage means.
FIG. 8 is a flowchart illustrating a process in which a CPU adjusts a charging voltage of a smoothing capacitor during motor operation according to a motor operating state.
[Explanation of symbols]
1 is a DC power converter, 3 is a bidirectional power converter for a motor, 4 is a smoothing capacitor, 7 is a power supply switch, 11 is a smoothing capacitor voltage sensor that feeds back a charging voltage of the smoothing capacitor 4, and 12 is a charging voltage of the smoothing capacitor. 18 is a CPU, 22 is a DC voltage detecting means for detecting a predetermined charging voltage of a smoothing capacitor, 23 is a digital potentiometer, 24 is a means for grasping the output voltage of the smoothing capacitor voltage sensor, Reference numeral 25 denotes storage means for storing characteristics of the output voltage of the smoothing capacitor voltage sensor with respect to the charging voltage of the smoothing capacitor.

Claims

A DC power converter that converts an AC power source into a DC power source and controls the voltage of the DC power source, a smoothing capacitor that is connected to the DC power converter and serves as a DC power source, and a motor that is connected to the smoothing capacitor and rotationally drives the rotor A bidirectional power converter for a motor that performs rotation control, a power supply switch that turns on and off the supply of power from an AC power source to the DC power converter, and a charging voltage of the smoothing capacitor that controls the DC power converter In a centrifuge having a control circuit for controlling and a motor control device including a smoothing capacitor voltage sensor for outputting a charging voltage feedback signal of the smoothing capacitor to the control circuit, a predetermined predetermined value of the smoothing capacitor is provided. DC voltage detection means for detecting a charging voltage, control means for controlling the control circuit, and output voltage of the smoothing capacitor voltage sensor And storage means for storing characteristics of the output voltage of the smoothing capacitor voltage sensor with respect to the charging voltage of the smoothing capacitor, and the control means controls the control circuit when the motor is stopped to charge the smoothing capacitor. The DC voltage detection means detects a predetermined charging voltage of the smoothing capacitor, stores characteristics of the output voltage of the smoothing capacitor voltage sensor with respect to the charging voltage of the smoothing capacitor in the storage means, and operates the motor. When the control circuit is controlled based on the characteristics of the output voltage of the smoothing capacitor voltage sensor with respect to the charging voltage of the smoothing capacitor stored in the storage means, the charging voltage of the smoothing capacitor is adjusted according to the operating condition of the motor. A centrifugal separator having a motor control device.

Bidirectional power converter for power supply that converts AC power supply power to DC power supply power or DC power supply power to AC power supply power, and power supply from AC power supply to bidirectional power converter for power supply is turned on / off A power supply switch, a reactor connected to the AC side of the bidirectional power converter for power supply, a smoothing capacitor connected to the DC side of the bidirectional power converter for power supply, and a rotor connected to the smoothing capacitor to rotate the rotor Controls the motor bi-directional power converter that controls the rotation of the motor to be driven, and controls the power bi-directional power converter to keep the charging voltage of the smoothing capacitor constant and suppress harmonic components of the AC power source current A power factor improvement control circuit for supplying power, a power supply voltage sensor for outputting a power supply voltage feedback signal of an AC power supply to the power factor improvement control circuit, and a power supply current feedback for an AC power supply to the power factor improvement control circuit. A power supply current sensor for outputting a click signal, in a centrifuge having a control apparatus for a motor having a smoothing capacitor voltage sensor which outputs a charge voltage feedback signal of the smoothing capacitor to the power factor improvement control circuit, the smoothing capacitor DC voltage control means for controlling the charging voltage of the smoothing capacitor by adjusting the voltage of the smoothing capacitor charging voltage feedback signal output from the voltage sensor, and a DC voltage for detecting a predetermined charging voltage predetermined for the smoothing capacitor Detection means; control means for controlling the power factor correction control circuit and the DC voltage control means; means for grasping the output voltage of the smoothing capacitor voltage sensor; and the smoothing capacitor voltage sensor with respect to the charging voltage of the smoothing capacitor. Storage means for storing output voltage characteristics is provided, and the control The stage controls the power factor correction control circuit and the DC voltage control means to adjust the charging voltage of the smoothing capacitor when the motor is stopped, detects the predetermined charging voltage of the smoothing capacitor by the DC voltage detection means, and The characteristic of the output voltage of the smoothing capacitor voltage sensor with respect to the charging voltage of the capacitor is stored in the storage means, and the output voltage of the smoothing capacitor voltage sensor with respect to the charging voltage of the smoothing capacitor stored in the storage means during operation of the motor A centrifuge having a motor control device, wherein the DC voltage control means is controlled based on the characteristics of the motor and the charging voltage of the smoothing capacitor is adjusted in accordance with the operating condition of the motor.