Predictive current control of an active harmonic filter

Voltage and current harmonics can have various deleterious effects on the entire power system, from residential households to power utilities. The onus to correct these harmonic problems lies dually with the end user and the power utilities. Active harmonic filters (AHFs) are one solution that can ensure the supply of clean power to end users in a distributed system. Research into AHFs has become an area of growing interest in the recent years. This is due to the increased use of non-linear loads, coupled with greater demand for electricity in general. This paper outlines the development of simulations and low voltage modelling of a pure AHF. The filter is composed of a three-phase inverter direct-connected in shunt with the load and a microcontroller used to implement the control strategy. The control algorithm and filtering are performed in the dq rotating reference frame. This implementation attempts to improve the control scheme proposed by Akagi et al (2007a) for pure AHFs. The output stages ofAkagi's control scheme are replaced with a predictive current controller with space vector modulation. Simulation and experimental results are provided to support the findings of this paper.