A novel compensator using static induction thyristors for reactive power and harmonics

The discussion is presented of the test results of a prototype compensator which compensates for the harmonic currents and instantaneous reactive power in a power system. The compensator is composed of a PWM (pulsewidth-modulated) converter with instantaneous current control and SI (static induction) thyristors which have better switching characteristics than the gate turn-off thyristor which has been used as a power switching device previously. The use of SI thyristors allowed the authors to develop a practical compensator whose main circuit is more compact than before. The compensation algorithm effects instantaneous power control based on the instantaneous spatial vector. This permits the hardware with the same configuration to perform multiple compensating functions by just changing the software.<>