摘要 |
<p>PURPOSE:To improve a specific error and a phase angle without affecting the stability of an operation of a circuit by a method wherein an electronic circuit installed only in a secondary circuit, an auxiliary current transformer and an impedance component are installed in an ordinary two-winding type current transformer. CONSTITUTION:A correcting impedance component 50 is inserted into a secondary circuit 12 of a first current transformer 10; a correcting electric current obtained via an electronic circuit and a second current transformer 40 flows to the correcting impedance component 50 in a constant-current mode; a voltage drop due to an intrinsic secondary electric current in the correcting impedance component 50 is compensated by a voltage drop due to the corrective electric current. Accordingly, an excitation voltage becomes zero apparently. By this setup, an influence of a secondary leakage impedance and a load of the first current transformer 10 are eliminated; a specific error and a phase angle of the first current transformer can be improved.</p> |