Shunt Active Power Filter: A Review on Phase Synchronization Control Techniques

Abstract

Owing to the destructive impacts of harmonic currents, the topic of reducing their impacts on power system has attracted tremendous research interests. In this regard, a shunt active power filter (SAPF) is recognized to be the most reliable instrument. It performs by first detecting the harmonic currents that are present in a harmonic-contaminated power system, and subsequently generates and injects corrective mitigation current back into the power system to cancel out all the detected harmonic currents. This means that other than the ability to generate corrective mitigation current itself, it is actually more important to make sure that the SAPF is able to operate in phase with the operating power system, so that the mitigation current can correctly be injected. Hence, proper synchronization technique needs to be integrated when designing the control algorithms of SAPF. This paper critically discusses and analyzes various types of existing phase synchronization techniques which have been applied to manage operation of SAPF; in terms of features, working principle, implementation and performance. The analysis provided can potentially serve as a guideline and provision of information on selecting the most suitable technique for synchronizing SAPF with the connected power system.

Sliding mode controller‐based voltage source inverter for power quality improvement in microgrid

“…The relay and signum method and hysteresis method of SMC is based on the discontinuous control action expressed in (9) and (10). Discontinuous state functions led to oscillations in the vicinity of surfaces in the system space [31].…”

“…Generally, shunt active power filters (APFs) [7][8][9][10][11] are used to mitigate the issues affecting the quality of power and to perform reactive power compensation. However, the APF strategy leads to the additional circuitry including the dc to ac power conversion circuit.…”

Modeling and Simulation of a PI Controlled Shunt Active Power Filter for Power Quality Enhancement Based on P-Q Theory

“…The concept of the shunt active power filter is rather modest. Before connecting the filter at the point of common coupling (PPC), the current flow in the power system is expressed as follows [34]:…”

“…Subsequently, when the SAPF is installed at the PCC, two additional currents are presented: the harmonic compensation current generated by the SAPF which is equal in magnitude with the harmonic current, but the phase is shifted by 180 • ; and the DC-link current (i dc ) that is exploited by the SAPF to keep the DC-link voltage (V dc ) at the desired level. The current flow in the power system is then expressed as [34] i…”

“…When the voltage across the DC-link capacitor is maintained at the predetermined level, the generated harmonic compensation current will be precisely identical to the harmonic current drawn by the nonlinear load, where they will cancel out each other. In regard to this, the system's current becomes sinusoidal with the fundamental frequency, and the expression in (2) becomes as follows [34]:…”