| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an AC filter capable of suppressing an increase in a low-order harmonic current, shortening of the lifetime of an apparatus due to an excessive phase advance and an increase in power loss due to increased apparent power without closing a phase advance capacitor for a high-order shunt in a state where a phase advance capacitor for a low-order shunt is not charged. <P>SOLUTION: In this AC filter 1, a plurality of shunts constructed from switches S<SB>5</SB>, S<SB>7</SB>, S<SB>11</SB>, reactors L<SB>5</SB>, L<SB>7</SB>, L<SB>11</SB>and phase advance capacitors C<SB>5</SB>, C<SB>7</SB>, C<SB>11</SB>connected in series are connected in parallel to a load Z of a power system, the switches S<SB>5</SB>, S<SB>7</SB>, S<SB>11</SB>are opened and closed and the phase advance capacitors C<SB>5</SB>, C<SB>7</SB>, C<SB>11</SB>are closed or cut off, according to the magnitude of lagging reactive power. Closing the phase advance capacitors C<SB>5</SB>, C<SB>7</SB>, C<SB>11</SB>is performed in the order of the ones corresponding to a low-order harmonic current and cutting off the phase advance capacitors C<SB>5</SB>, C<SB>7</SB>, C<SB>11</SB>is performed in the order of the ones corresponding to a high-order harmonic current. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
