Design of Parallel Hybrid Active Power Filter

Abstract

With the rapid development of social economy, electric energy plays an indispensable role in social life and has become an important symbol of the country’s comprehensive national strength. However, with the rapid development of power electronic technology, many nonlinear loads appear in the power system, which has become the most important harmonic source in the power system. Harmonics will not only affect the normal operation of various electrical equipment, but also damage the peripheral communication system and equipment of public power grid. Therefore, we must control the harmonics in the power grid. The traditional treatment scheme is to use LC passive filter (PF), but it can only filter out harmonics of a specific number of times. In addition,it is sensitive to power grid parameters, may produce resonance, so that the harmonics are amplified, and the volume of the filter device is huge. In order to overcome the above problems, active power filter (APF) appears, which can dynamically compensate harmonics according to harmonic frequency and size, and has excellent flexibility and practicability. However, in terms of cost, the cost of APF with the same capacity is much higher than that of PF. Therefore, based on the respective characteristics of PF and APF, this paper makes an in-depth research and design of hybrid active power filter (HAPF). In this system, the passive filter completes the main harmonic compensation and reactive power improvement, while the active filter is used to help the passive filter overcome the disadvantage of easy resonance.