减少农机能源浪费必须采取综合技术措施

2010年底,我国大中型拖拉机保有量近400万台,小型拖拉机保有量近2000万台。与此同时,农机在农业生产中的能源消耗越来越高,农机作业已成为我国消耗柴油量最多的一个行业。由于管理水平低,修理和保养不当,导致油料浪费现象严重。因此,我们必须采取综合措施减少农机能源的浪费。

新能源农机用双永磁游标电机的模型预测电流控制

模块化双永磁游标电机兼具高转矩密度和低铁耗,适用于低速大转矩的直驱应用领域。针对新能源农机用模块化双永磁游标电机控制系统存在的转矩脉动大、电流谐波多和转速波动大等问题,提出一种基于改进式模型预测电流控制策略。相比于传统模型预测电流控制,提出的控制策略采用双矢量模型预测电流控制,在每个控制周期内可同时选择2个任意电压矢量组合作用,扩大了电压矢量的选择和幅值调节范围,可进行更准确的电流控制。同时,考虑系统延迟,在预测控制中加入电流延迟补偿环节。仿真结果表明,所提的控制策略可有效减小转矩脉动、电流谐波和转速波动,提升系统的控制性能。

新能源农机充电系统设计探究

随着全球能源结构的转型和农业现代化的推进,新能源农机作为农业生产中节能减排的重要工具,是未来农机装备的发展和转型方向之一[1]。新能源农机充电系统的研究与开发显得尤为重要。本文首先阐述了新能源农机充电系统的研究背景,指出了其在促进农业可持续发展、减少环境污染和提高能源利用效率方面的重要作用。在系统设计原则部分,本文详细讨论了系统兼容性、能源效率优化以及安全性与可靠性,为充电系统的设计提供了指导。探讨了新能源农机充电技术的发展,包括无线充电技术的应用、快速充电技术的进步和智能充电管理系统,介绍了技术进步对充电系统性能的提升。最后总结研究成果,提出了发展策略建议。

新能源农机装备的发展现状与趋势

党的十九大报告对乡村振兴战略提出要坚持农村优先发展,按照产业兴旺、生态宜居、乡风文明、治理有效、生活富裕的总要求,加快推进农业农村现代化。新能源农机装备零污染、低噪声,是促进农业绿色发展、节能减排保护生态、建设宜居乡村的重要工具。近年来,农业农村部、工业和信息化部、国家发展改革委等多个部门相继推出政策,加快新能源农机装备的研发推广。国内自主研发的新能源农机产品越来越多,但由于核心技术相对落后、人才储备严重不足等原因,产品整体的市场竞争力较弱。文章通过查阅大量文献,梳理和总结出国内外新能源农机装备在农作物耕、种、管及收4个生产环节应用的现状,并提出各环节新能源农机装备产品与技术的发展趋势。同时,深入剖析我国在发展新能源农机装备过程中存在的问题,进一步提出具体的促进新能源农机装备发展的建议。

Study on an Undershot Cross-Flow Water Turbine

This study aims to develop a water turbine suitable for ultra-low heads in open channels, with the end goal being the effective utilization of unutilized hydroelectric energy in agricultural water channels. We performed tests by applying a cross-flow runner to an open channel as an undershot water turbine while attempting to simplify the structure and eliminate the casing. We experimentally investigated the flow fields and performance of water tur- bines in states where the flow rate was constant for the undershot cross-flow water turbine mentioned above. In addition, we compared existing undershot water turbines with our undershot cross-flow water turbine after at- taching a bottom plate to the runner. From the results, we were able to clarify the following. Although the effec- tive head for cross-flow runners with no bottom plate was lower than those found in existing runners equipped with a bottom plate, the power output is greater in the high rotational speed range because of the high turbine ef- ficiency. Also, the runner with no bottom plate differed from rtmners that had a bottom plate in that no water was being wound up by the blades or retained between the blades, and the former received twice the flow due to the flow-through effect. As a result, the turbine efficiency was greater for runners with no bottom plate in the full ro- tational speed range compared with that found in runners that had a bottom plate.