Active Low-Frequency Ripple Control for Clean-Energy Power-Conditioning Mechanism

This paper focuses on the design of an active low-frequency ripple control for a clean-energy power-conditioning mechanism with an aim to protect clean-energy sources (e.g., solar photovoltaics, fuel cells, etc.) from the severe damage of current-ripple propagation to expand their life span. First, a simplified circuit for representing the current-ripple phenomenon inside a general power conditioner including a dc/dc converter and a dc/ac inverter is derived, and the dynamic model of the active low-frequency ripple-control circuit is analyzed. Moreover, an adaptive linear neural network is taken as a neural filter to generate the compensation current command, and a total sliding-mode controller is designed to manipulate the ripple-control circuit for injecting a suitable compensation current into the high-voltage bus of the conditioner. In addition, the effectiveness of the proposed active low-frequency ripple-control scheme is verified by numerical simulations and experimental results. Its superiority is indicated in comparison with a conventional high-pass filter and a proportional-integral controller.