| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an active filter which can contribute to stable operation of the system and enhancement of power quality by removing harmonic noise other than the basic wave in a system where many and unspecified harmonics exist. <P>SOLUTION: In accordance with the basic expression (1) of power equation, effective power value P and reactive power value Q are determined by integration operation of instantaneous effective power value and instantaneous reactive power value, an estimated value of instantaneous voltage is calculated, the system side basic wave current is determined therefrom and subtracted from the load current thus determining the output of an active filter, that is, a compensation current. In the expression (1), P is the effective power value, Q is the reactive power value,νis the instantaneous voltage (its real part is the measured value of instantaneous voltage), i is the instantaneous current (its real part is the measured value of instantaneous current), and i* is the conjugate of the current i. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
