THREE-PHASE ACTIVE ELECTRIC FILTER Russian patent published in 2002 - IPC

FIELD: electrical engineering; converter engineering; off-line power systems. SUBSTANCE: filter has input-data conversion system connected to supply phase leads that incorporates adapter whose output is connected to analog input of single-chip computer; output of the latter is connected to input of buffer stage; leads of secondary windings of matching current transformers are connected on one end to supply phase leads and on other end leads of these windings are interconnected to form node; primary windings of these transformers are connected to outputs of pulse power amplifiers whose inputs are connected to outputs of NOT gates and relay components; inputs of NOT gates are connected to outputs of relay components whose inputs are connected to outputs of error adders; negative inputs of the latter are connected to outputs of pulse power amplifiers and positive ones, to outputs of adders; negative inputs of the latter are connected to output of buffer stage; secondary outputs of data current transformers are connected on one end to adapter input and to positive inputs of adders; on other end secondary winding leads are interconnected to form node. EFFECT: improved power characteristics of off-line systems due to reduced higher harmonics of voltage components across check points of power system feeding high-power nonlinear loads. 1 dwg