A system consisting of an internal combustion engine (ICE) directly coupled to an electric machine for power generation as in range extenders is considered in this brief. The engine power is mostly controlled by acting on the throttle. A second control loop regulates the air-to-fuel ratio by measuring the exhaust oxygen and acting on the fuel-mass flow, whereas the electric machine is usually considered only for the energy conversion. In this brief, the influence of the throttle and the generator speed on the power control is studied. Moreover, a control strategy is proposed that, by acting on the generator, allows the power control without the need of a throttle actuator. The baseline system was compared with the proposed control strategy. The power control leads to a nonlinear control system that is dealt with via feedback linearization. The control strategy was designed and tested in an experimental prototype. The results validate the proposed control structure that ensures a high fuel conversion efficiency within a wide power range and foregoes the throttle actuator. The highest possible fuel conversion efficiency difference in the operation range is 10%.

中文翻译：

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无节气门执行器内燃机的非线性功率控制

本简报考虑了一种系统，该系统由直接连接到用于发电的电机（如增程器）的内燃机 (ICE) 组成。发动机功率主要通过作用于油门来控制。第二个控制回路通过测量废气中的氧气并作用于燃料质量流量来调节空燃比，而电机通常仅用于能量转换。在这个简介中，研究了油门和发电机转速对功率控制的影响。此外，提出了一种控制策略，通过作用于发电机，无需节气门执行器即可进行功率控制。基线系统与建议的控制策略进行了比较。功率控制导致非线性控制系统，该系统通过反馈线性化处理。控制策略是在实验原型中设计和测试的。结果验证了所提出的控制结构，该结构可确保在较宽的功率范围内实现高燃料转换效率，并且无需节气门执行器。运行范围内可能的最高燃料转换效率差异为 10%。