| 摘要 |
PURPOSE:To reduce generation of direct current short-circuit, by making a converter to be by-path pair state at trouble time such as instant breakage of electric source and others, making load current to return, and restarting from the converter which is in this state at recovery of normal state. CONSTITUTION:Capacity to detect direction of electric current is added on an output current detector 12 whih has been used in the object such as detection of zero value of electric current formerly, by using diodes 21, 21' and detection resistors 22, 22'. From this, since it is possible to judge the direction of electric current, in addition to zero value of current, it can be judged at by-pair time which 3 phase bridge is conductive in two sets of bridges. Therefore, 3 phase bridge which is by-path pair at instant breakage or abnormal drop of electric source can be restarted by this function. From this, when electric source is recovered to normal state, after instant breakage or abnormal drop of electric source, stable operation can be done at once, and the reliability of all system can be improved. |
