Control method for parallel-connected hybrid power filters

The parallel operation of several low-capacity harmonic filters is better than the singular operation of one high-capacity harmonic filter due to the advantages of extensibility and higher reliability. Furthermore, the use of a harmonic filter with the function of parallel operation is an important trend. In this paper, a control method for the parallel-connected hybrid power filters is proposed. This control method can automatically balance the current distribution among parallel-connected hybrid power filters. In order to verify the performance of the proposed control method, a prototype consisting of two hybrid power filters is developed. The experimental results show that the performance of the proposed control method is as desired.