Series compensation on power system with very low harmonic distortion

This paper describes a series compensation scheme employing a capacitor in parallel with two PWM switched reactor modules. The two module PWM switched reactors provide continuously variable reactance by employing simple duty ratio control. The switching instants of the two reactor modules are contro lled to have 180 degrees phase shift, but equal duty ratio, to achieve harm onic cancellation. The complete series compensator provides a wide range of capacitive and inductive compensation. The harmonic distortion produced by this series compensation scheme with a single switched reactor and two swi tched reactors is analyzed and compared. An experimental model of the propo sed compensator has been simulated, constructed and tested. In the case of the two module system the voltage harmonics have been found to be well belo w the IEEE 519-1992 recommended limit with a switching frequency of only 30 0 Hz. Nodulating this new compensator with a swing between minimum capaciti ve compensation and maximum capacitive compensation atl Hz shows its fast d ynamic response. The simplicity of the scheme and the quality of the result s indicates potential as another useful FACTS Controller.