This paper introduces a novel approach to enhance the control algorithm for a single-phase shunt active power filter(SAPF) by integrating a new technique into a 5-level cascaded multilevel inverter (MLI) with.
What is a notch filter?
A notch filter can be used at the output of the phase detect block, which attenuates twice the grid frequency component very well. An adaptive notch filter can also be used to selectively notch the exact frequency in case there are variations in the grid frequency.
What is adaptive notch filter?
All key algorithms such as phase locked loop (PLL) for grid synchronization and proportional resonant (PR) controllers provide good gain at selected frequencies. The adaptive notch filter actively dampens the resonance of the LCL filter that is implemented.
What is a notch filter equation?
A typical notch filter equation is 's' domain as shown in Equation 19: Equation 20 maps well into a digital two-pose two-zero structure and the coefficients for the notch filter can be adaptively changed as the grid frequency varies by calling a routine in the background that estimates the coefficients based on measure grid frequency.
How to update notch filter coefficient?
Call the SPLL_1ph_init routine with the frequency of the ISR the SPLL will be executed in as parameter and the grid frequency and then call the notch filter update coefficient update routine.
The successful implementation of the proposed system positions the MNFSOGI controller as a robust and reliable solution for controlling multilevel inverters in scenarios involving distorted grid conditions.
Mastromauro et al. developed a single-phase, low-power photovoltaic system intended for harmonic compensation and grid voltage support. A decoupled adaptive noise detection-based control method for a four-leg VSC was proposed by Singh and Jain et al. in .