Parallel Association of Shunt Active Power Filters

Abstract

This paper describes different types of parallel association of Shunt Active Power Filters, presents computer simulation models developed in PSCAD®/EMTDC™, and shows simulated results for each case. The control system used in the active filters is based on the Instantaneous Reactive Power Theory (p-q Theory). The active filters use periodic sampling as switching technique. Two types of parallel associations are presented: two active filters in different parallel feeders; and both active filters connected in parallel at the same point of the electric installation. The paper also proposes a control strategy to solve an inherent operation problem that occurs in the second type of parallel association.

Computer Studies of the Operation of a Three-Phase Four Wire Shunt Active Power Filter Applied to the Industry

“…A SAPF can be single-phase or three-phase. The purpose of a SAPF is to make the currents in the electrical power grid sinusoidal and in phase with the power grid voltages, balance the current of the three phases which leading to a practically null neutral current [8] [11]. The aim is to supply, from the electrical power grid to the loads, only the necessary active power.…”

“…The SAPF used in this study presents a three-phase four-wire power electronics converter. The Fryze-Buchholz-Depenbrock theory is used to calculate the reference currents to carry out the correct power management of the system [8]. In order to obtain results from real factory situations, the real loads of the factory, that is, production lines and electrical switchboards, were modeled in order to understand the effectiveness and benefits of the application of the SAPF.…”

Parallel operation of inverters and active power filters in distributed generation system—A review

“…When these APFs are working in different feeders or deal with separate loads, as in Fig. 15, then no central control mechanism is needed even though they are apparently in parallel operation [51].…”

Performance Improvement of Active Power Filter using a New Control Strategy under Unbalanced Grid Voltage

“…Most of the industrial applications need current harmonic compensation so the shunt active filter is more popular than series active filter. [8,9,11,12] Different approaches have been proposed and implemented for extracting the harmonic current, such as the instantaneous power theory developed and defined by Akagi in 1984 based in three phase three wires. This theory gives good performance for balanced supply condition; however, when the voltage source is significantly unbalanced, performance is poor, [13,14,15,16] and it was later modified and extended by Nabae and applicable to the 4 wires , unbalanced systems (modified PQ theory or PQR theory).…”