Recently, the number of accessories in vehicle powertrains has been significantly increased. These accessories are necessary for vehicle operation. Accessories are driven by the engine, so their power demands result in a reduction of the vehicle's useful power. For heavy-duty vehicles, the most demanding accessories are the alternator; fan drive; heating, ventilation, and air-conditioning compressor, and brake air compressor. Their power demands vary according to the engine speed, and this may lead to notable energy losses especially in certain conditions, such as engine idling. This paper aims to evaluate the accessories power demands on a tractor equipped with an engine rating of 192 kW. In this tractor, a data logger together with auxiliary sensors were installed to monitor their power demands. During idling conditions, accessories power demands reach 38% of the power provided by the engine and this leads to non-negligible impact on fuel consumption. The fuel consumption caused by accessories and their potential fuel savings by introducing electrically-driven accessories into tractor powertrains were estimated. A potential fuel saving of 232 l per year could be attained. This may lead to a yearly saving of 278 million litres of fuel and 747 thousand tons of CO₂ in the US. These savings were calculated assuming that all tractors are used with the same duty cycle. Even if it may not occur, thus the actual savings may be significantly different than that reported in this study, it permits to estimate if farming may benefit from tractors with electrically driven accessories.

近来，车辆动力总成中的附件的数量已显着增加。这些附件是车辆操作所必需的。附件由发动机驱动，因此其功率需求会导致车辆的有用功率减少。对于重型车辆，最苛刻的附件是交流发电机；风扇驱动器；供暖，通风和空调压缩机，以及制动空气压缩机。它们的功率需求根据发动机转速而变化，这可能导致明显的能量损失，尤其是在某些情况下，例如发动机空转。本文旨在评估配备192 kW发动机的拖拉机的附件功率需求。在这台拖拉机中，安装了一个数据记录器和辅助传感器，以监视其功率需求。在空转条件下，配件的动力需求达到了发动机提供动力的38％，这对燃油消耗的影响不可忽略。估计了由附件引起的油耗，以及通过将电动附件引入拖拉机动力总成中所带来的潜在燃料节省。潜在节省燃油232 每年可以达到l。在美国，这可能导致每年节省2.78亿升燃料和74.7万吨CO ₂。假设所有拖拉机均以相同的占空比使用，则可计算出这些节省额。即使可能不会发生，因此实际节省的费用可能与本研究报告的费用明显不同，它可以估算出农业是否可以从带有电动附件的拖拉机中受益。