POWER FEEDING SYSTEM

PROBLEM TO BE SOLVED: To provide a power feeding system capable of switching a supply source of a voltage to a load without instantaneous interruption.SOLUTION: First and second semiconductor switch parts 8, 9, 11, and 12 have such characteristics that they are turned on under control of a controller 6 when a potential difference of a predetermined value or more is generated at both ends and turned off when a current flowing between both ends is the predetermined value or less. A voltage converter 5 generates an AC output voltage having a phase shifted to a system voltage so that a voltage difference between the system voltage and an AC output voltage becomes the potential difference or more at a predetermined timing. The controller 6 controls the first and second semiconductor switch parts 8, 9, 11, and 12 by utilizing the characteristics so that the first and second switches 7 and 10 are not simultaneously in an on state at a switching operation, and so that at least one of the first semiconductor switch parts 8 and 9 and the second semiconductor switch parts 11 and 12 are in an on state when both first and second switches 7 and 10 are in an off state. 【課題】負荷に対する電圧の供給元を無瞬停で切り替え可能な給電システムを提供する。【解決手段】第１および第２半導体スイッチ部８、９、１１、１２は、両端に所定値以上の電位差が発生しているときに制御部６の制御下でオンし、かつ両端間を流れる電流が所定値以下になったときにオフする性質を有し、電圧変換部５は、所定のタイミングで系統電圧と交流出力電圧との電圧差が上記電位差以上となるように系統電圧に対して位相がずれた交流出力電圧を生成し、制御部６は、切替動作時に、第１および第２スイッチ７、１０が同時にオン状態とならないように、かつ第１および第２スイッチ７、１０の双方がオフ状態となるときに第１半導体スイッチ部８、９または第２半導体スイッチ部１１、１２の少なくとも一方がオン状態となるように、上記性質を利用して第１および第２半導体スイッチ部８、９、１１、１２を制御することを特徴とする。【選択図】図１