Method and apparatus for determining orders of non-characteristic harmonic currents, and for compensation of the noncharacteristic harmonic currents

摘要

PCT No. PCT/DE92/01063 Sec. 371 Date May 26, 1995 Sec. 102(e) Date May 26, 1995 PCT Filed Dec. 10, 1992 PCT Pub. No. WO94/14220 PCT Pub. Date Jun. 23, 1994A method and an apparatus can determine the orders (z) of non-characteristic harmonic currents (Ih) of a second power supply grid, which is coupled to a first power supply grid using an HVDCT system. The apparatus and method also compensates for these non-characteristic harmonic currents (Ih), which are produced as a result of distortion (Uh) of the supply voltage (U1) which exists in the first grid because of a low-frequency harmonic and passes through the short coupling. The order (n) of the existing non-characteristic harmonics is determined by a voltage and/or current measurement of the voltage (U1) of the grid, from which order (n) the order (z) of the generated non-characteristic harmonics in the second grid is determined by a provided voltage-symmetry signal (SMG). This order (z) is supplied to filter logic of a compensation system. The energy quality is thus considerably improved, particularly in the case of grids which are not rigid.