Active Power Filter Based On Active Power Balance Principle And Ant Colony Algorithm Optimized PI Regulator

With the development of economics, the linear and nonlinear loads increased sharply, and result in serious pollution of harmonic and reactive power in the power system. Recently, the technology of active power filter (APF) trends to be mature, and APF becomes the effective solution to harmonic elimination and reactive power compensation. To meet compensating requirement of power system, a novel compensating method is proposed.In this paper, the harmonic and reactive power effects on power system are discussed sufficiently, and kinds of existed approaches to detect harmonic and reactive power are analyzed and compared each other; to improve the transient characteristics of APF system, the power balance principle is applied to harmonic and reactive power detection. By detecting the dc-link voltage of converter at all positive zero-crossing instance, the variety of dc-link voltage can be attained; then a three-phase sinusoidal reference current in-phase with the source phase-voltages can be calculated, and its amplitude is a constant in a detective period and refreshes every detective period; finally, make the source current trace this reference current, thus achieve the purpose of harmonic and reactive power compensation. This method needn't have made complex calculation for separating harmonic and reactive component from load current; because of discrete detection of dc-link voltage, APF system avoids low-pass filters; as a real-time and close-loop control mode, hysteresis comparison control mode has a simple hardware and good response characteristic; based on ant colony optimization algorithm (ACOA) optimized the parameter of PI regulator, the dynamic indexes of APF system are improved.Through simulation in the software of MATLAB, the results show that this compensating approach is viable.