An active AC bridge with adaptive current orthogonal decomposition for precision measurement of dielectric loss angle

With adaptive orthogonal decomposition of reactive and active current, an active AC bridge, which is implemented by employing analog circuit, is introduced. Its application in measurement of dielectric loss angle for high voltage insulation apparatus can eliminate the effect of harmonics of testing voltage, reduce leakage resistance and capacitance and ease high resolution. Moreover, determination of the reference voltages for orthogonal decomposition and the dynamical characteristics of the bridge are presented.