Fast Repetitive Control With Harmonic Correction Loops for Shunt Active Power Filter Applied in Weak Grid

Improved SHM‐PAM‐based five‐level CHB inverter to fulfil NRS 048‐2:2003 grid code and to apply as shunt active power filter with tuned proportional‐resonant controller for improving power quality

“…To overcome this problem, active power filter (APF) is the most effective and preferred solution. In literature, several current control strategies have been discussed for the APF system [6][7][8][9] that avoid the undesired current harmonic distortions and clean the utility. Among these, the proportional-resonant (PR) current controller [8,9] is well known for APF architecture because of its several advantages like (i) it provides infinite gain at resonant frequency and minimises the steady-state error, (ii) it has a simple computational process and (iii) it is less sensitive to parameter variation.…”

“…1) emerged as the most suitable topology because of its several attractive features over the other multilevel inverter (MLI) topologies [1,2]. It has been widely used in medium-voltage (MV) high-power gridconnected applications such as renewable energy integration, static synchronous compensator, shunt active power filter (SAPF), unified power flow control [3][4][5][6][7][8][9], etc. All aforementioned applications have their own objectives, but it is essential to keep the harmonic magnitudes of the inverter output voltage within the acceptable limits as mentioned by certain grid code standards [10][11][12].…”

Adaptive repetitive controller for an active power filter in three ‐ phase four ‐ wire systems

“…The main objective of the design of compensating current control is to track reference currents from the harmonic identification with the smallest error. Previous related works [14–24] have focused on the PI controller, the proportional plus resonant (PR) controller, and the RT controller because the concept of these controllers is to improve the steady‐state tracking error. The PI controller is widely used and is less complex.…”

Applying Directly Modified RDFT Method in Active Power Filter for the Power Quality Improvement of the Weak Power Grid

“…Compared with the ordinary distribution network, the weak power grid characterized by large grid impedance suffers from more severe power quality problems such as voltage and frequency fluctuation, harmonics, imbalance [3,4]. These power quality issues may cause a series of hazards such as the abnormal operation of the sensitive load, additional losses of the electric power equipment and the reduction of their service life, the decline of the power transmission efficiency, and interference in communication [5,6]. Therefore, power quality problems in the weak power grid should be well handled.…”

“…Therefore, power quality problems in the weak power grid should be well handled. Among the several power quality improvement measures, the shunt active power filter (SAPF), based on the principle of the controlled current source, provides a flexible and effective solution for the weak grid [6][7][8]. It can inject a compensation current characterized by the equal amplitude and the opposite phase compared with the load-side reactive and harmonic current to ensure the grid-side unity power factor and sinusoidal current.…”