Simulations of a Current-Source Shunt Active Power Filter with Carrier- Based PWM and Periodic Sampling Modulation Techniques Bruno Exposto, Helder Carneiro, Carlos Couto, João L. Afonso UNIVERSITY OF MINHO Department of Industrial Electronics 4800-058 - Guimarães, Portugal Tel.: +351 253 510 190. Fax: +351 253 510 189. E-Mail: bexposto@dei.uminho.pt, hcarneiro@dei.uminho.pt, carlos.couto@dei.uminho.pt jla@dei.uminho.pt URL: http://www.gepe.dei.uminho.pt Acknowledgements This work is financed by FEDER Funds, through the Operational Programme for Competitiveness Factors – COMPETE, and by National Funds through FCT – Foundation for Science and Technology of Portugal, under the project PTDC/EEA-EEL/104569/2008. Keywords Current Source Inverter (CSI), Active Power Filter, Power Quality, Modulation Strategy, Simulation, Pulse Width Modulation (PWM). Abstract This paper presents a Shunt Active Power Filter that is built using a current-source inverter. The control of the Active Filter relies in the p-q Theory with the “Sinusoidal Currents at Source” algorithm implemented. The Active Power Filter was simulated using two modulation techniques: Periodic Sampling and Carrier-Based Pulse Width Modulation (CBPWM). To assess the performance of the Active Filter, the simulations were made using two different loads. The first load was a RL balanced load. The second was a non-linear load, namely a full bridge rectifier with a RL load in the DC side. These loads allowed determining the performance of the Active Filter when compensating current harmonics and power factor, using the two modulation techniques. Introduction Non-linear loads are very common in the industrial installations nowadays. These types of loads consume currents with high levels of harmonic content, which causes Power Quality problems. In addition, the existence of industrial facilities with low power factor causes problems related with energy efficiency and overdimensioning of cables. All these problems represent economical wastes and as said before reduction of energy efficiency. The conventional solutions used for solving and mitigate these problems, such as tuned passive filters for current harmonics and capacitor banks for power factor correction, do not solve them in a suitable way, and can cause other problems, such as resonances. Therefore, it is necessary to find new solutions to these problems. Shunt Active Power Filters are a more suitable solution that allows the dynamic compensation of current harmonics and power factor, without causing the problems that the passive filters and capacitor banks can cause. The Active Filters are traditionally built using voltage-source inverters. Differently from the conventional solutions, in this paper is presented a Current-Source Shunt Active Power Filter. In the last few years there has been growing research on Current-Source Active Filters [1] [2], but it is still necessary to perform studies of their operation under different types of loads and inverter modulation technics. The proposed Current-Source Shunt Active Filter was simulated using two modulation techniques: Periodic Sampling and Carrier-Based Pulse Width Modulation (CBPWM). These two modulation techniques have been successfully used in Voltage-Source Active Filters [3]. The control technique of Exposto, B.; Carneiro, H.; Pinto, G.; Couto, C.; Afonso, J.L., "Simulations of a current-source Shunt Active Power Filter with Carrier-Based PWM and Periodic Sampling Modulation Techniques", Proceedings of the 2011-14th European Conference on Power Electronics and Applications (EPE 2011), pp.1-8, 30 Aug. - 1 Sept., 2011.