Grid Integration of a Multi-Objective Single Stage PV System Using Tapped Delay Continuous Time LMS Based Control Technique

Abstract

In this paper, a photovoltaic (PV) array is interfaced to a three-phase distribution network. A three-leg voltage source converter (VSC) is used for injecting power to the utility. The PV array is connected to DC bus capacitor of VSC. The maximum power is harvested from the PV array, by generating a reference DC bus voltage, making the use of an incremental conductance (INC) derived MPPT technique. A tapped delay continuous time least mean square (TDCTLMS) based control scheme, is utilized to estimate switching pulses for the VSC switches. For improvement in system response to abrupt changes in irradiance, and grid voltage variations, the control includes a PV feed-forward term. The response is evaluated on an experimental prototype, for balanced and unbalanced nonlinear loads, and dynamic conditions of irradiance variations, and abrupt load unbalancing. The PV system demonstrates the additional functions of correction of power factor, grid currents balancing, and harmonics currents mitigation to within the IEEE 519 standard.