High flexibility and low cost digital implementation for modern PWM strategies

Abstract

In this paper a new low cost technique for PWM strategy implementation is presented. The proposed technique does not require dedicated hardware PWM units, thus offering higher flexibility of use. Furthermore, the aforementioned method eases the digital implementation of modern modulation methods like AZSPWM, NSPWM, or ACRPWM. By using a conventional PWM unit from a microcontroller, these modern modulation techniques are often difficult, or even impossible, to implement. The proposed method can be used to implement PWM strategies even for those microcontrollers which are not equipped with hardware PWM unit. The experimental results show that this new technique is suitable to replace traditional implementation methods with minimum computational overhead, with the benefit of high flexibility, lower cost and faster code development.

On discussion of DC side EMI filter design for conducted noise suppression in photovoltaic system

“…This has become an urgent problem to be solved. Traditional methods of suppressing the leakage currents are by changing main circuit topologies [1], [5][6], by improving control strategies [7][8] or by inserting EMI filters [2][3][4]. This paper mainly focuses on the DC side EMI filters of the PV system.…”