Title :
A new type of STATCOM based on cascading voltage source inverters with phase-shifted unipolar SPWM
Author :
Liang, Yiqiao ; Nwankpa, C.O.
Author_Institution :
CEGELEC Autom., Pittsburgh, PA, USA
Abstract :
In this paper, a new type of STATCOM is proposed. This new STATCOM is constructed by cascading several identical full bridge (H bridge) voltage source inverters (VSI). A so called phase-shifted SPWM unipolar voltage switching scheme is applied to control the switching devices of each VSI. The harmonics in STATCOM current caused by the DC voltage ripple are rejected by a new method developed in this paper. As a result, the size of inductor and DC capacitors can be further reduced. A very effective startup procedure is proposed to start up the STATCOM. The proposed STATCOM has the advantages of a reduced number of VSIs; the VSIs being identical and extremely fast in response to reactive power change.
Keywords :
DC-AC power convertors; PWM invertors; bridge circuits; harmonic distortion; power conversion harmonics; static VAr compensators; thyristor convertors; DC capacitors; DC voltage ripple; H-bridge VSI; STATCOM; cascading voltage source inverters; full-bridge VSI; inductor; phase-shifted unipolar SPWM; power convertor current harmonics; reactive power change response speed; startup procedure; switching devices control; unipolar voltage switching scheme; Automatic voltage control; Bridge circuits; Capacitors; Diodes; Inductors; Inverters; Reactive power; Switches; Switching circuits; Voltage control;
Conference_Titel :
Industry Applications Conference, 1998. Thirty-Third IAS Annual Meeting. The 1998 IEEE
Conference_Location :
St. Louis, MO, USA
Print_ISBN :
0-7803-4943-1
DOI :
10.1109/IAS.1998.730333
