基于短路电流法的温差发电最大功率点跟踪控制  

Maximum Power Point Tracking Scheme for Thermoelectric Generators Based on Short-Circuit Current Method

作　　者：王军[1] 阎铁生[1] 陈亮[1] 黄涛 呼爱国 Wang Jun;Yan Tiesheng;Chen Liang;Huang Tao;Aiguo Patrick Hu(Key Laboratory of Fluid and Power Machinery Ministry of Education Xihua University,Chengdu 610039,China;Department of Energy Politecnico di Torino Torino 10129 Italy;Department of Electrical&Computer Engineering University of Auckland Auckland 1142 New Zealand)

机构地区：[1]西华大学流体及动力机械教育部重点实验室,成都610039 [2]都灵理工大学能源系,都灵10129 [3]奥克兰大学电气工程系,奥克兰1142

出　　处：《电工技术学报》2020年第2期318-329,共12页Transactions of China Electrotechnical Society

基　　金：四川省科技计划（2019YFH0167）;成都市科技局国际合作项目（2016-GH02-00111-HZ）资助

摘　　要：温差发电器(TEG)是一种将热能直接转化为电能的新能源发电装置,使用变换器实现对其输出的最大功率点跟踪(MPPT)极为重要。针对温差发电器件存在内阻随外部温度变化、最大功率点随外部温度变化的问题,该文提出一种新的温差发电短路电流最大功率点跟踪控制算法。首先采用微控制器采集变换器电感电流,通过深入分析TEG与Boost变换器等效模型,推导出根据电感电流瞬时值及其斜率估算温差片短路电流的方法,使用PI控制器将电感电流有效值控制在短路电流的一半,从而实现最大功率点跟踪。与传统算法不同,此方法仅需采集电感电流值,无振荡、无静差,对变换器正常工作无影响。最后通过仿真和实验进行验证,结果表明,所提出的短路电流最大功率点跟踪方法能够有效地跟踪全局最大功率点,仅需要一组电流传感器,工作过程不影响主电路正常工作,既减少了成本,又提高了可靠性。Thermoelectric Generator(TEG),as a new energy generator,can convert heat into electricity energy directly,and maximum power point tracking(MPPT)plays a crucial role in this energy harvesting and conversion process.However,the internal resistance of TEG and maximum power point change with the external temperature.Therefore,a new short-circuit current MPPT algorithm for TEG is proposed in this paper.By analyzing the equivalent model of TEG and Boost converter,the proposed method can estimate the short-circuit current of TEG by using the instantaneous inductor current and its slope.Then the MPPT is achieved by a PI controller to regulate the root-mean-square value of the inductor current at half of the short-circuit current of TEG.Different from the traditional algorithms,the proposed method realizes MPPT without steady-state errors and oscillations,and has no negative effect on the normal operation of the converter.Finally,the simulation and experimental results show that the proposed method can effectively track the global maximum power point with only one current sensor,and the tracking process does not affect the normal operation of the main circuit,which reduces the cost and improves reliability.

关 键 词：温差发电器 升压变换器 最大功率点跟踪 电感电流 短路电流 

分 类 号：TM464[电气工程—电器]