Active filtering of electric power has now become a mature technology for harmonic and reactive power compensation in two-wire (single phase), three-wire (three phase without neutral), and four-wire (three phase with neutral) AC power networks with nonlinear loads. This paper presents a comprehensive review of active filter (AF) configurations, control strategies, selection of components, other related economic and technical considerations, and their selection for specific applications. It is aimed at providing a broad perspective on the status of AF technology to researchers and application engineers dealing with power quality issues. A list of more than 200 research publications on the subject is also appended for a quick reference.

A review of active filters for power quality improvement

Attention has been paid to active filters for power conditioning which provide the following multifunctions: reactive power compensation; harmonic compensation; flicker/imbalance compensation; and voltage regulation. Active filters in a range of 50 kVA-60 MVA have been practically installed in Japan. In the near future, the term "active filters" will have a much wider meaning than it did in the 1970s. For instance, active filters intended for harmonic solutions are expanding their functions from harmonic compensation of nonlinear loads into harmonic isolation between utilities and consumers, and harmonic damping throughout power distribution systems. This paper presents the present status of active filters based on state-of-the-art power electronics technology, and their future prospects and directions toward the 21st Century, including the personal views and expectations of the author.

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New trends in active filters for power conditioning

Unlike traditional passive harmonic filters, modern active harmonic filters have the following multiple functions: harmonic filtering, damping,isolation and termination, reactive-power control for power factor correction and voltage regulation, load balancing, voltage-flicker reduction, and/or their combinations. Significant cost reductions in both power semiconductor devices and signal processing devices have inspired manufactures to put active filters on the market. This paper deals with general pure active filters for power conditioning, and specific hybrid active filters for harmonic filtering of three-phase diode rectifiers.

Active Harmonic Filters

New regulations impose more stringent limits on current harmonics injected by power converters that are achieved with pulsewidth-modulated (PWM) rectifiers. In addition, several applications demand the capability of power regeneration to the power supply. This work presents the state of the art in the field of regenerative rectifiers with reduced input harmonics and improved power factor. Regenerative rectifiers are able to deliver energy back from the dc side to the ac power supply. Topologies for single- and three-phase power supplies are considered with their corresponding control strategies. Special attention is given to the application of voltage- and current-source PWM rectifiers in different processes with a power range from a few kilowatts up to several megawatts. This paper shows that PWM regenerative rectifiers are a highly developed and mature technology with a wide industrial acceptance.

http://www.lcda.cl/descargas/rodriguez_dixon_pont_espinoza_lezana05.pdf

PWM regenerative rectifiers: state of the art

A shunt active filter based on the instantaneous active and reactive current component i/sub d/-i/sub q/ method is proposed. This new control method aims to compensate harmonics and first harmonic unbalance. To evaluate its relative performance, it is compared with the instantaneous active and reactive power p-q method under various mains voltage conditions and for different harmonic injection high-pass filters. Both methods are completely frequency-independent, however under distorted mains voltages the proposed method presents a better harmonic compensation performance. The system synthesis and implementation are performed. Simulation and experimental results are presented.

An instantaneous active and reactive current component method for active filters

The modeling, analysis, and design of an active power filter using quad-series voltage source pulsewidth modulated (PWM) converters are presented. Some instantaneous space vectors of voltage and current are used for the analysis. A vector differential equation derived in this paper makes it easy to achieve the analysis and design of the active power filter. Experimental waveforms obtained from a prototype active power filter with a rating of 7 kVA, along with simulation waveforms, are included to verify the theory presented. >

Yukifumi Tsukamoto

Papers

Analysis and design of an active power filter using quad-series voltage source PWM converters

A Design of an Active Power Filter using Multi-Series Voltage Source PWM Converters