| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a mechanism for accurately constraining a ripple of neutral point current and neutral point potential of a three-phase NPC converter for even high frequency component with an easy control algorithm. <P>SOLUTION: A neutral point clamp type power conversion equipment according to an embodiment of the present invention comprises: a neutral point clamp (NPC) type three-phase inverter that is connected to a DC power supply having three potentials to drive three-phase load and can output three levels, means 12 for calculating a three-phase voltage command; neutral point potential fluctuation constraining means 23 for calculating the compensation amount of zero-phase bias voltage in order to constrain the fluctuation of the neutral point potential according to the three-phase voltage command and a current feeding into the load; and means 14 for correcting the three-phase voltage command by adding the compensation amount of zero-phase bias voltage to the three-phase voltage command. The neutral point potential fluctuation constraining means 23 comprises means for calculating the compensation amount of the zero-phase bias voltage according to at least the absolute value and a sign of the three-phase voltage command, and the load current. <P>COPYRIGHT: (C)2012,JPO&INPIT |
