| 摘要 |
PROBLEM TO BE SOLVED: To achieve a simple active filter control method without individually detecting an individual constituent to be compensated. SOLUTION: A saw-tooth wave being the same as the fundamental frequency of a power supply is used to convert a receiving end voltage to d-q coordinates without detecting actual electrical angle θv, a low-pass filter is used for separating a DC component containing an extremely low frequency, the electrical angle of the fundamental wave of the receiving end voltage being obtained according to the sum of the arc tangent of the ratio of the d- and q-axis components of the DC component and the saw-tooth wave is used for converting a load current to the d-q coordinates, another low-pass filter is used similarly for separating the DC content containing the extremely low frequency on the d axis, and the electrical angle θv is used for converting to a-b-c coordinates, thus detecting the effective current of the positive-phase component of the fundamental wave of the load current, and obtaining the difference between the effective current of the positive-phase component of the fundamental wave of the current flowing into the load and the load current as the command value of an active filter. |
