Digital signal processor implementation and performance evaluation of split capacitor, four-leg and three H-bridge-based three-phase four-wire shunt active filters

ArticleinIET Power Electronics 4(4):463 - 470 · May 2011with42 Reads
DOI: 10.1049/iet-pel.2010.0198 · Source: IEEE Xplore
Abstract
In this paper a comprehensive study on the three-phase four-wire (3P4W) shunt active power filter (APF) is carried out on the basis of three system configurations. These three two-level voltage source inverter topologies are compared for 3P4W shunt APF, namely, split capacitor (2C), four-leg (4L) and three single-phase H-bridges (3HB). The performance of all three topologies, under an unbalanced non-linear load condition, is evaluated with a detailed digital signal processor (DSP)-based experimental investigation. The steady-state as well as dynamic performance of APF is studied to compensate for current harmonics, reactive power, current unbalance and neutral current. The advantages and limitations offered by each of the topologies are also discussed in brief.
    • "This is the main reason why novel definitions for such quantities have been proposed in literature [11]. As it was mentioned before, conventional APFs are normally designed to provide reactive power and harmonic compensation simultaneously [12]–[15]. It is worth to mention that the active power redistribution is also possible considering that a given phase with highest loading can send power to the remaining ones so that balanced currents exist, while only positive sequence components are supposed to flow through the system. "
    [Show abstract] [Hide abstract] ABSTRACT: This paper presents a power electronic converter used to redistribute the power among the phases in unbalanced power systems, which is supposed to be designed based on the involved degree of unbalance. A bidirectional converter is chosen for this purpose, whose modeling is presented in the dq0 system. This solution can be considered as part of a unified control system, where conventional active power filters )APFs) may be solely responsible for compensating harmonics and/or the tuning of passive filters becomes easier, with consequent reduction of involved costs in a decentralized approach. The adopted control strategy is implemented in DSP (digital signal processor) TMS320F2812, while experimental results obtained from an experimental prototype rated at 17.86 kVA are properly discussed considering that the converter is placed at the secondary side of a transformer supplying three distinct single-phase loads. It is effectively shown that the converter is able to balance the currents in the transformer phases, thus leading to the suppression of the neutral current.
    Full-text · Article · Apr 2016
    • "The compensation capability of an active filter depends on various parameters such as dc link voltage (v dc ), dc storage capacitor (C dc ), interface inductor (L f ) and so on. In order to drive the filter currents, the value of dc link voltage should have a minimum value of 1.6 times the peak value of system line voltage (V lm ) as discussed in Khadkikar et al. [13], George and Mishra [17]. Once the value of v dc is selected, the value of C dc can be determined from the transient period in the system and its ability to regulate under this condition as given in Singh et al. [18]. "
    [Show abstract] [Hide abstract] ABSTRACT: This paper proposes a modified four-leg distribution static compensator (DSTATCOM) topology for compensation of unbalanced and nonlinear loads in three-phase four-wire distribution system. DSTATCOM, connected in parallel to the load, supplies reactive and harmonic powers demanded by unbalanced nonlinear loads. In this proposed topology, the voltage source inverter (VSI) of DSTATCOM is connected to point of common coupling (point of interconnection of source, load, DSTATCOM) through interface inductor and series capacitance, unlike the conventional topology which consists of interface inductor alone. Load compensation with a lower value of input DC link voltage of VSI is possible in this modified topology compared to conventional topology. A comparative study on modified and conventional topologies in terms of voltage rating of inverter power switches, switching losses in VSI and power rating of input DC capacitor of VSI is presented. The detailed design aspects of DC link capacitor and interface series capacitor are also presented. The reference filter currents are generated using instantaneous symmetrical component theory and are tracked using hysteresis current control technique. A detailed simulation study is carried out, to compare the compensation performances of conventional, modified topologies using PSCAD simulator and experimental studies are done to validate the simulation results.
    Full-text · Article · Jun 2014
  • [Show abstract] [Hide abstract] ABSTRACT: An increased level of harmonics due to the proliferation of single-phase non-linear loads is raising serious concerns among utilities. Historically, passive filters have been proposed to reduce harmonics in MV utility applications. However, due to their limitations utilities are turning their attention to alternative solutions. At the same time, active filters are prohibitively expensive and are unlikely to become a realistic solution in the near future. In this paper a practical directional third harmonic hybrid active filter is proposed. A novel feature that adjusts the level of compensation provided by the filter based on the loading conditions of its passive components is introduced. Simulation and experimental results are presented. Issues related to utilizing existing VAr support capacitors for retrofit applications thereby achieving cost reduction and fail normal feature for increased reliability are addressed. Cost vs. performance curves are developed using factual utility harmonic data. Finally, the impact of a distributed filtering solution based on the proposed filter is shown using a simplified MV distribution system.
    Conference Paper · Sep 2012
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