An Analysis on the Effectiveness of Harmonics Reduction for Variable Frequency Drive by Reactors

Abstract

Recently, due to the rapid development of Power Electronics, the usage of Non Linear Load variable frequency drivers (VFDs) is increasing in the electric propulsion vessels and offshore plants. And harmonics which is generated by the variable frequency drives is an important issue should be solved. Ac line reactors and dc link reactors are widely used in variable frequency drives to improve the drive performance such as reducing input current harmonics, elevating input power factor, and protecting the drives from surges, etc. The effectiveness of both types of reactors in reducing input harmonics is affected by the loading of the drives and the system source impedance. And it considered that inductance of DC link reactors should be about 1.7 times of AC line reactors for same effect. The rules to evaluate the needs and effectiveness using ac line or dc link reactors are proposed for practical appications. In this paper, a simulation is performed to investigate of such factors using software PSIM.