This study deals with a newly-conceived voltage control method for three-phase four-leg voltage source inverters (VSIs) which are being required in autonomous power generating units devoted to supply both three-phase and single-phase electrical loads in four-wire electric power distribution systems. To deal with VSI operating conditions providing three-phase voltage supply of both unbalanced loads and non-linear loads, an integral + resonant (I + R) voltage control structure is discussed and experimentally verified by means of a 25 kVA rated power converter prototype. It is shown that the proposed voltage control allows simplifying the overall control configuration, achieving zero-overhead power factor regulation and fast compensation of load unbalances. Further to that, a complete current limiting strategy is described and tested under different load conditions.
[1]
Ian R. Petersen,et al.
Multivariable integral control of resonant structures
,
2008,
2008 47th IEEE Conference on Decision and Control.
[2]
Poh Chiang Loh,et al.
A comparative analysis of multiloop voltage regulation strategies for single and three-phase UPS systems
,
2003
.
[3]
Vicente Feliu,et al.
Integral Resonant Control for Vibration Damping and Precise Tip-Positioning of a Single-Link Flexible Manipulator
,
2011,
IEEE/ASME Transactions on Mechatronics.
[4]
Ying-Yu Tzou,et al.
High-performance programmable AC power source with low harmonic distortion using DSP-based repetitive control technique
,
1997
.