摘要 |
Apparatus for injection voltage compensation in series into an electric power line includes an inverter or other controlled voltage source which wye connects the secondary windings of a three-phase transformer to the load end of the electric power line. The transformer, which could already be present for meeting load requirements, has its primary winding connected to the source end of the electric power line and sustains the saturation currents rather than the inverter in response to faults on the source side of the transformer. Preferably, a three-phase inverter with a common dc link is used. For active power line conditioner (APLC) action, a second, also preferably a three-phase, inverter is connected in parallel to the load end of the electric power line and to the common dc link. This parallel inverter provides harmonic and reactive power compensation and also supplies the real power requirements of the wye connection inverter. |