电动机离散变频软起动分频及最优切换相位控制

为了提高重载时异步电动机离散变频软起动的性能,解决采用标准触发角起动中各频段切换时产生较大的转矩脉动及转速波动等问题,进行了分频相位组合以及最优切换相位的研究。通过对离散变频相位组合及其序分量的理论分析,得到合理的分频系数。针对三相不对称频段,采用对称分量法建立了相序分量表,求出了正序分量最大的相序组合。建立了离散变频软起动仿真模型,计算分析了各频段的电流和转矩,确定了最佳分频等级及过渡频段。对各频段采用不同切换相位进行仿真,得到了最优切换相位的确定规律。最终确定了一种最合理的离散分频软起控制方案,为离散变频闭环控制策略的研究提供了理论依据,为异步电机重载软起动提供了新思路。

基于模糊相似选择和接近度的电网谐波综合评估方法

为了分析区域电网谐波污染情况,构建了一种基于模糊相似选择和接近度的谐波综合评估方法.首先将评估对象的指标序列与评估等级序列进行比较分析,其次利用模糊贴近度和灰关联分析构成的接近度指标,分析评价结果,得出评估对象对于最优等级及相邻等级的隶属度,达到精细考察谐波污染情况的目的.该方法模型简单,计算便捷,指标扩展性好,适合于电能质量在线分析系统对谐波进行统一评估,实现谐波的智能治理.

Configuration information acquisition and matching in self-reconfiguring process of modular self-reconfigurable robots

Configuration information acquisition and matching are two important steps in the self-reconfiguring process of self-reconfigurable robots. The process of configuration information acquisition was introduced, and a self-reconfiguring configuration matching strategy based on graded optimization mechanism was proposed. The first-grade optimization was to search common connection between matching scheme and goal configuration. The second-grade optimization, whose object function was constructed in terms of configuration connectivity, was to search connnon topology according to the results of the first-grade optimization. The entire process of configuration information acquisition and matching was verified by an experiment and genetic algorithm （GA）. The result shows the accuracy of the configuration information acquisition and the effectiveness of the configuration matching method.

船舶岸电系统变电方案分析与设计

针对国内与国外岸电系统技术差距较大,尤其在船舶岸电系统变电方案设计方面研究较为落后的问题,研究船舶岸电系统最优电压等级计算方法,结合最优电压等级对比分析不同船舶岸电系统上船方式,提出合理的变电方案。