基于LMMHD波浪能发电机特性的高效实时输出功率控制系统

Efficient real-time output power control system based on LMMHD wave energy generator characteristics

针对目前液态金属磁流体(LMMHD)波浪能发电机输出功率控制系统响应慢、精度差、变换效率低、低压下不能可靠换向的问题,在LMMHD波浪能发电机输出特性分析的基础上,提出一种通过实时调节LMMHD发电机等效负载来控制发电机输出功率的控制策略,该控制策略快速准确且多模块并联时不存在并联均流问题。通过对考虑寄生参数影响的主电路效率的理论分析,得到了所提输出功率控制策略下主电路效率的变化规律,进而提出了多模块并联的方案,提高了系统效率,降低了单模块的设计难度。并提出了一种滚动时域判断和双模块独立驱动的换向驱动方法,在实现低压下可靠换向的同时避免了电流从体二极管流通,降低了导通损耗。仿真和样机实验结果验证了所提策略的有效性。

Aiming at the problems of slow response,poor accuracy,low conversion efficiency and unreliable commutation under low voltage in the current output power control system of liquid metal magneto-hydro dynamic(LMMHD)wave energy generators,a control strategy to control the generator output power by realtime adjusting the equivalent load of LMMHD generator is proposed based on the analysis of the output characteristics of LMMHD wave energy generators.This strategy is fast and accurate,and there is no parallel current sharing problem when multiple modules are connected in parallel.Through the theoretical analysis of the efficiency of the main circuit considering the influence of parasitic parameters,the variation rule of the main circuit efficiency under the proposed output power control strategy is obtained.Furthermore,a scheme of multi module parallel connection is proposed to improve the system efficiency and reduce the design difficulty of a single module.A commutation drive method of rolling time domain judgment and dual module independent drive is proposed,which can realize reliable commutation under low voltage while avoiding the current flow from the body diode and reducing the conduction loss.Results of simulative and prototype experiments verify the effectiveness of the proposed strategy.