Time-domain harmonic extraction algorithms for three-level inverter-based shunt active power filter under steady-state and dynamic-state conditions-an evaluation study

Abstract

Power quality is a major consideration in all office equipment, manufacturies and residential home appliances. Harmonic distortion is one of the crucial power quality issues. In order to mitigate the harmonic distortion, the performance of shunt active power filter (SAPF) is judged in terms of the accuracy and response time of its designed controller. In this context, the controller consists of three parts: harmonic extraction, switching control, and DC-link capacitor. The harmonic extraction technique serves the major role of deriving the required reference current to ensure successful mitigation of current harmonics by SAPF. Among the existing techniques, harmonic extraction algorithms based on time-domain approaches are most widely applied as they offer simple implementation features with increased speed and reduced computational burden. This paper presents detailed investigation and analysis regarding the performance of two famous time-domain harmonic extraction techniques namely, synchronous reference frame (SRF) and instantaneous power (PQ) theory. Extensive simulation work is conducted in MATLAB-Simulink platform under two conditions, which are, steady-state conditions and dynamic-state conditions, considering various highly nonlinear loads. For evaluation purposes, each control algorithm is incorporated into the controller of a three-phase SAPF, developed using a three-level neutral-point-clamped (NPC) inverter. Comprehensive results are provided to confirm mitigation performance of the SAPF utilizing each harmonic extraction algorithm.

Dynamic Performance Optimization of Shunt Active Power Filter to Eliminate Total Harmonic Distortion

“…During operation, a typical SAPF will first measure the harmonic contents of the harmonic fusing power system, and based on this measurement, the SAPF will create a compensating current to be injected back into the power system for mitigating the harmonic currents existing in the power system. It is vital to highlight that mitigation is deemed successful when the supply current can restore its sinusoidal form with a THD value of 5% or less [1], runs in phase, and has the same fundamental frequency as the source voltage [8,9].…”

An Observer-Based Harmonic Extraction Method with Front SOGI

“…Therefore, a fast and accurate real-time harmonic detection method under the influence of power grid fluctuations is the premise of other work. At present, the harmonic detection methods mainly include Fast Fourier Transform (FFT) [9,10], Instantaneous Reactive Power Theory (IRPT) [11,12], Synchronous Reference Frame (SRF) [13], Cascade Delay Signal Cancellation technology (CDSC) [14], and Kalman filter [15], in addition to improved techniques for these methods, etc. For example, Ref.…”

Active Power Filtering Under Unbalanced and Distorted Grid Conditions Using Modular Fundamental Element Detection Technique

“…Nevertheless, time-domain approaches especially synchronous reference frame (SRF) [13][14][15], and instantaneous power (pq) theory [8,[16][17][18] are still the more popular approaches where they have been recognized to offer the benefit of control structure simplicity. However, their control structures are rather rigid which restricted their flexibility to be adopted directly in different power system configurations.…”

“…One interesting manner to realize this has been reported in [15,19], where intensive modifications performed can clearly be observed. Besides, most of the existing works related to SRF techniques are still depending on numerical low-pass filter (LPF) to work [13,[19][20][21]. One inherent problem related to numerical filters is that they need to be tediously tuned to perform as desired.…”