| 摘要 |
<P>PROBLEM TO BE SOLVED: To estimate a phase (instantaneous phase) of an AC single-phase signal with a low operation load. <P>SOLUTION: A filter 11 generates a filter signal v<SB POS="POST">2</SB>by delaying the phase of a target single-phase signal v<SB POS="POST">1</SB>(vs) only by θ<SB POS="POST">1</SB>(0<θ<SB POS="POST">1</SB><π/2). A vector component calculation part 12 can convert a signal v<SB POS="POST">1</SB>and a signal v<SB POS="POST">2</SB>into a rotation vector on a fixed coordinate system using the phase difference θ<SB POS="POST">1</SB>between the signal v<SB POS="POST">1</SB>and signal v<SB POS="POST">2</SB>and can also convert the signal v<SB POS="POST">1</SB>and signal v<SB POS="POST">2</SB>into a vector on a rotating coordinate system using θ<SB POS="POST">1</SB>and θ. θ represents a phase of the rotating coordinate system viewed from the fixed coordinate system. A phase difference calculation part 13 calculates a phase difference Δθ between θ and the phase of the target single-phase signal v<SB POS="POST">1</SB>based on two orthogonal components v<SB POS="POST">p</SB>and v<SB POS="POST">q</SB>of the vector on the rotating coordinate system. An addition part 14 calculates an estimate θ<SB POS="POST">est</SB>of the phase of the target single-phase signal v<SB POS="POST">1</SB>by adding θ to Δθ. <P>COPYRIGHT: (C)2012,JPO&INPIT |
