The controller of turned filter based on self-optimizing

Compared to the active filters, passive filters are widely used for their cheaper costs, simpler structures and more reliable performance. But conventional passive filters which consist of parameter-fixed capacitors and reactors can not remain good filtering performances in case of the system frequency shifts or components parameters change. This article compares the advantages and disadvantages of two feasible control methods, through researching a sort of passive filter using controllable reactor instead of parameter-fixed reactor, then improves them and implements a control method based on self-optimizing control. Good performances of the filter are verified by experiments both in laboratory and at the locale of use. These prove the practical value of this control method.