Predictive direct power control with phase-locked loop technique of three-level neutral point clamped inverter based shunt active power filter for power quality improvement

In this study, an improved anti-windup proportional-integral predictive direct power control strategy with a phase-locked loop (PLL) is proposed and applied to a three-level shunt active power filter (SAPF) neutral point clamped (NPC) inverter using space vector modulation (SVM) technique. The SAPF has to ensure sinusoidal waveforms and unity power factor in the grid side, by eliminating harmonic currents and compensating reactive power of the nonlinear loads. Active and reactive powers as well as the DC bus voltage controls are performed using anti-windup proportional and integral actions with a predictive algorithm, without a need for an exhaustive mathematical model. The control law is modulated using the SVM technique allowing fixed switching frequency and low power ripples. The performances of the suggested control have been verified through an electronic STM32F407 card under diverse and severe conditions. The obtained results confirmed the expected objectives in terms of current and voltage quality, robustness, and dynamic response. Direct power control approach featuring Phase-Locked Loop (PLL), which is implemented in a three-level Shunt Active Power Filter (SAPF) neutral point clamped (NPC) inverter utilizing space vector modulation (SVM) technique. The SAPF's objective is to guarantee grid-side sinusoidal waveforms and unity power factor, while mitigating harmonic currents, compensating reactive power, reducing Total Harmonic Distortion (THD) in the current, enhancing the longevity of the filtration system, and refining the system's dynamic response.image