余热发电并网系统最大效率跟踪控制方法  

Maximum Efficiency Tracking Control Method for Waste Heat Power Generation Grid-connected System

作　　者：黄守道[1] 李雪萍 王家堡 冯垚径 HUANG Shou-dao;LI Xue-ping;WANG Jia-bao;FENG Yao-jing(Hunan University,Changsha 410082,China)

机构地区：[1]湖南大学电气与信息工程学院,湖南长沙410082

出　　处：《电力电子技术》2019年第1期26-29,共4页Power Electronics

基　　金：国家自然科学基金青年项目(51407064);国家重点研发计划重点专项(YFB0606000)~~

摘　　要：传统的余热发电并网系统中,膨胀机无法根据热源变化而工作在相应的最大效率点,针对此问题提出了一种膨胀发电系统结合变流器控制的最大效率跟踪控制方法。首先结合膨胀机特性及相似理论推导出膨胀机各工况下最优效率点对应的各参数之间的关系,得到膨胀机最佳转速计算方法,并通过机侧变流器控制发电机组跟踪最佳转速,使膨胀机实时达到效率最优。其次由于膨胀机在变工况下宽转速运行,为实现系统变工况下高效并网发电,在低速时,变流器采用i_(sd)=0控制,转速上升至发电机端电压超过直流母线电压时,系统自动切换为弱磁控制,拓宽发电机转速并提高系统带载能力。最后通过仿真和实验验证了所提方案的正确性和可行性。In the traditional waste heat power generation grid-connected system,the expander can not work in the corresponding maximum efficiency point according to the heat source changes,aiming at this problem,a maximum efficiency tracking control method for the expander-generator system combined with the converter control is presented.Firstly,the relationship between the parameters of the optimal efficiency point under the off-design condition of the expander is deduced by combining the expander characteristics and similarity theory,the optimal speed calculation method of the expander is obtained,and through the generator-side converter to control the generator set to track the best speed,so that the expander achieves the best efficiency in off-design condition.Secondly,as the expander works wintin the wide speed range under off-design condition,in order to achieve high efficiency of grid-connected power generation system under off-design condition ,the converter uses isd=0 control at low speed,when the speed rises to the generator terminal voltage exceeding direct current bus voltage,the system automatically switches to flux-weakening control to broaden the speed of power generation system and improve the system load-carrying capacity.Finally, the correctness and feasibility of the proposed scheme are verified by simulation and experiment.

关 键 词：膨胀机 最大效率跟踪控制 变工况 弱磁控制 

分 类 号：TB653[一般工业技术—制冷工程]