A LCCR filter based harmonic suppression method for power quality improvement

Abstract

As power converters have been widely used in renewable energy generation and motor drive system for the industrial production, the harmonics of output voltage of power converter will seriously affect the system power quality. To improve power quality of the converter, passive filters such as L-type filters, LC-type filters and LCL filters can are used, which have large volume and poor performance under certain conditions. Aiming at reducing the output harmonic characteristics of PWM power converter, this paper analyzes the frequency characteristics of LCCR filter and proposes a new parameterized model of LCCR filter. Based on the parameterized model of LCCR filter, a high-precision parametric design method of LCCR filter with resonance suppression is also presented in this paper. The frequency characteristics of LCCR filter are designed by a set of four-element methods with frequency characteristic parameters, which can eliminate the coupling relationship between the parameters. The frequency characteristics of the LCCR filter can be directly reflected by the defined parameter. The parameterized design method of LCCR filter presented in this paper can reduces the complexity of multi-parameter LCCR filter design, effectively improves the accuracy and rapidity of filter design. Both the analytical and experimental results validate that the LCCR filter can be accurately designed to suppress the harmonics caused by power converters.

Keywords

• PWM power converter
• LCCR filter
• Harmonic suppression