1993 Volume 113 Issue 3 Pages 317-324
The super-conducting type MAGLEV, which is directly driven by the VVVF inverters or the cycloconverters, is well-known as the new traction system for the future super-rapid mass transportation.
Since the frequency converters generate harmonic currents possibly leading to the interference problem on utility's transmission system, the conventional AC filter of LC (reacter-capacitor) branch and/or the active filter is necessary to prevent the harmonic disturbances.
We have developed a novel harmonic compensation system consisting of shunt LC filters on load side, a step-down transformer on receiving end, and a small-capacity active filter which one end is connected to the secondary winding of the transformer and the other to the load bus.
The active filter is current-controlled to give adequate damping to the harmonic resonance condition between the power system and the passive filter equipment especially at lower harmonic frequencies.
We will describe the principle and the characteristics of the new harmonic compensation system, and its labolatory test results which show satisfactory performance.