Topology Optimizaton of Active Power Filters

Abstract

Abstract. Active power filters (APF) are an important research domain, since several years ago. However the industrial use of APF is almost inexistent due to their high acquisition cost and to the absence of widely accepted criteria for usefulness. In most situations, where APF would be adopted, the plant management prefers a passive filter solution, considering simplicity, cost and rudeness. Consequently, power filtering is good for the mains network but presents a limited interest for the plant manager. Power quality in the user plant must be the main objective of active filters, instead of the suppression of harmonic content in the mains currents. This one must be a secondary objective, also achieved, but less important for the plant management, unless the contract with the power company obliges the reduction of current harmonic distortion. This approach is required to obtain the economic viability of active power filters. Consequently, the main economic objective of power filtering must be the power quality in the user plant. The power quality parameters can be evaluated as factors of cost in the design of active power filters. Another concern on the design and use of active power filters is the problem of the radio frequency conducted noise induced in the mains network. The hard switching technology, for bridge power converters, has been replaced, in our design of APF, by soft-switching technology. This paper presents a new design approach of APF based on the association of full-bridge hf soft-switching DC-DC converter with 6 cycloconverters (integral cycle control).