The PI current control of a single-phase inverter has well known drawbacks: steady-state magnitude and phase error and limited disturbance rejection capability. When the current controlled inverter is connected to the grid, the phase error results in a power factor decrement and the limited disturbance rejection capability leads to the need of grid feed-forward compensation. However the imperfect compensation action of the feed-forward control results in high harmonic distortion of the current and consequently non-compliance with international standards. In this paper a new control strategy aimed to mitigate these problems is proposed. Stationary-frame generalized integrators are used to control the fundamental current and to compensate the grid harmonics providing disturbance rejection capability without the need of feed-forward grid compensation. Moreover the use of a grid LCL-filter is investigated with the proposed controller. The current control strategy has been experimentally tested with success on a 3 kW PV inverter.
|Titolo:||A new control structure for grid-connected LCL PV inverters with zero steady-state error and selective harmonic compensation|
|Data di pubblicazione:||2004|
|Nome del convegno:||19th Annual IEEE Applied Power Electronics Conference, APEC 2004|
|Digital Object Identifier (DOI):||10.1109/APEC.2004.1295865|
|Appare nelle tipologie:||4.1 Contributo in Atti di convegno|