Optimized control of three-phase inverters to minimize total harmonic distortion in a grid-connected photovoltaic system

Abstract

Currently, the energy transfer process to the grid of the PV system is based on the importance of less harmonics and high efficiency. The evaluation of harmonics distortion of current is based on the value of THDi (<<5%), this last becomes very high if the current leakage is high, which causes losses of the grid and safety problems. Therefore, our job is to improve the classic control method of PV inverters used to reduce grid loss and improve electricity prices. This study is a proposal toward the modelization and improvement of the three-phase two-level, and multi-level photovoltaic (PV) inverter command, using space vector, and sinusoidal control based on controlling the active and reactive current delivered into the grid indirectly with a resonant controller (PIR) for a nonlinear load (NLL). The results of the simulations obtained by the new control methodology, SPWM, and SVPWM show that its performance is better compared with the simple modulation (PWM); the total harmonic distortion (THD) of current in both methods (SVPWM) and (SPWM) is better than that obtained with conventional commands. Also, multilevel converters control produces better quality waveforms, reducing current harmonic distortion.

An Application of Neural Network-based Sliding Mode Control for Multilevel Inverters

“…The neural estimators in [24,25] are applied to approximate the upper bound of the lumped nonlinearities in the active power filter. In 3-phase MLIs, several challenges persist, including the utilization of carriers for modulation and the implementation of current controllers for regulation [26]. These factors result in a reduction in dynamic response and an increase in over-shoot or under-shoot.…”

Reduction of common mode voltage for grid-connected multilevel inverters using fuzzy logic controller

“…This also causes the switching loss to increase. While the CMV magnitude of grid-connected multilevel inverters in [31]- [33] has not been considered and evaluated quantitatively.…”

“…The fuzzy logic method has been applied in many fields of control [34]- [38]. However, in gridconnected CM3Is, it still exists some problems such as using the carrier waves for modulating and the PI current controllers for controlling [33]. These cause the dynamic response to decrease and the over-ISSN: 2088-8694  shoot/under-shoot to increase.…”