国四以上柴油发动机限扭故障分析

国四以上柴油发动机在现代交通和工业中获得了广泛应用,然而,其在运行过程中可能会出现限扭故障,进而会影响发动机的整体性能和可靠性。文章深入分析了国四以上柴油发动机常见限扭故障的原因、诊断方法以及预防与维护措施。首先,探讨了限扭故障的常见原因,包括排放控制装置故障、传感器和控制单元问题、燃油系统问题等,详细介绍了其中一些关键问题,如选择性催化还原系统故障、柴油颗粒捕捉器故障等。然后,探讨了限扭故障的诊断方法,包括使用故障诊断工具、现场观察与检查等,以帮助快速准确地定位和解决问题。最后,强调了预防与维护的重要性,强调了定期维护与保养、使用高质量的燃油和润滑油等关键措施,以减少限扭故障的风险,提高柴油发动机的可靠性和使用性能。

Hybrid Operation of Fault Current Limiter and Thyristor Controlled Braking Resistor

The effectiveness of a combination of fault current limiter and thyristor controlled braking resistor on power system stability enhancement and damping turbine shaft torsional oscillations has been studied. If both devices operate at the same bus, the stabilization control scheme can be carried out continuously and with flexibility. As a result, the fault currents are limited, and the generator disturbances and the turbine shaft torsional oscillations are converged quickly. In this paper, the effectiveness of the combination of both devices has been demonstrated by considering 3LG （three-lines-to-ground） fault in a two-machine infinite bus system. Also, temperature rise effect of both devices with various resistance values and weights has been demonstrated. Simulation results indicate a significant power system stability enhancement and damping turbine shaft torsional oscillations as well as with allowable temperature rise.