On the voltage ripple reduction control of the linear switched reluctance generator for wave energy utilization

This paper discusses about the voltage output ripple reduction and error minimization for the direct-drive, linear switched reluctance generator (LSRG)-based wave power generation system. First, the concept of the LSRG-based wave power generation system is studied. According to the characteristics of the LSRG, the suitable drive circuit dedicated to proper current excitation and generation is established. Second, the reasons that cause voltage output ripples are investigated. To reduce the remarkable ripples from phase current commutations, a current distribution function (CDF) is proposed based on the minimized copper loss principle. Third, the dual-loop control strategy with current and voltage as the inner and outer loop is constructed, implemented with the proposed CDF. Theoretical bases of the control strategy are derived. The simulation results prove that the proposed control algorithm is capable of voltage ripple suppression and error reduction within the range of ±0.5 V over the entire operation speed for wave energy extraction, validated by experimental verification.