柴油发电机组转速测量保护系统的优缺点有哪些？ What are the advantages and disadvantages of the speed measurement and protection system for diesel generator sets?

柴油发电机组转速测量保护系统的优缺点：

　　这套系统具有很大的优点，尤其是超速系统具有多重保护功能。它的传感器（测速探头）和被测量的旋转物体没有直接接触，所以没有磨损，拆装维修方便，机组运行时也可以维修更换探头，接线也方便。其中主机的速度变送器还具有11P1（发电机轴承预润滑泵）操控、励磁投入、同期闭锁、电气超速跳机（>565 r/min）、调速器超速跳机（>575 r/min）等功能。同时在柴油机本体上还设置了机械超速保护（>595 r/min）系统，在很大程度上保证了柴油机安全稳定运行（额定转速500 r/min），不会出现飞车事故。但同时也存在一些问题：飞轮高速运转时的窜动会造成探头损伤，转速表经常出现波动甚至无转速，电气超速保护误动等，还出现了由于转速指示波动使柴油发电机预润滑泵频繁启停（>100 r/min时停，<100 r/min时开），导致烧毁发电机轴承预润滑泵电机或其接触器线圈的情况。

Advantages and disadvantages of the speed measurement and protection system for diesel generator sets:

This system has great advantages, especially the overspeed system with multiple protection functions. Its sensor (speed probe) does not have direct contact with the rotating object being measured, so there is no wear and tear. It is easy to disassemble and repair, and the probe can also be repaired and replaced during the operation of the unit. The wiring is also convenient. The speed transmitter of the host also has functions such as 11P1 (generator bearing pre lubrication pump) control, excitation input, synchronous locking, electrical overspeed trip (>565 r/min), and governor overspeed trip (>575 r/min). At the same time, a mechanical overspeed protection system (>595 r/min) is also installed on the diesel engine body, which largely ensures the safe and stable operation of the diesel engine (rated speed of 500 r/min) and prevents runaway accidents. But there are also some problems: the movement of the flywheel during high-speed operation can cause damage to the probe, the tachometer often fluctuates or even has no speed, electrical overspeed protection misoperation, etc. There are also cases where the diesel generator pre lubrication pump frequently starts and stops due to speed indication fluctuations (stops when>100 r/min, opens when<100 r/min), resulting in the burning of the generator bearing pre lubrication pump motor or its contactor coil.