Multilevel Inverter For Grid-Connected PV System Employing Digital PI Controller
Selvaraj, J.; Rahim, N.A.
Industrial Electronics, IEEE Transactions on
Volume 56, Issue 1, Jan. 2009 Page(s):149 - 158
Digital Object Identifier 10.1109/TIE.2008.928116
Summary:This paper presents a single-phase five-level photovoltaic (PV) inverter topology for grid-connected PV systems with a novel pulsewidth-modulated (PWM) control scheme. Two reference signals identical to each other with an offset equivalent to the amplitude of the triangular carrier signal were used to generate PWM signals for the switches. A digital proportional-integral current control algorithm is implemented in DSP TMS320F2812 to keep the current injected into the grid sinusoidal and to have high dynamic performance with rapidly changing atmospheric conditions. The inverter offers much less total harmonic distortion and can operate at near-unity power factor. The proposed system is verified through simulation and is implemented in a prototype, and the experimental results are compared with that with the conventional single-phase three-level grid-connected PWM inverter.
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