柴油發(fā)電機組轉速測量保護系統(tǒng)的優(yōu)缺點:
這套系統(tǒng)具有很大的優(yōu)點,尤其是超速系統(tǒng)具有多重保護功能。它的傳感器(測速探頭)和被測量的旋轉物體沒有直接接觸,所以沒有磨損,拆裝維修方便,機組運行時也可以維修更換探頭,接線也方便。其中主機的速度變送器還具有11P1(發(fā)電機軸承預潤滑泵)操控、勵磁投入、同期閉鎖、電氣超速跳機(>565 r/min)、調速器超速跳機(>575 r/min)等功能。同時在柴油機本體上還設置了機械超速保護(>595 r/min)系統(tǒng),在很大程度上保證了柴油機安全穩(wěn)定運行(額定轉速500 r/min),不會出現(xiàn)飛車事故。但同時也存在一些問題:飛輪高速運轉時的竄動會造成探頭損傷,轉速表經(jīng)常出現(xiàn)波動甚至無轉速,電氣超速保護誤動等,還出現(xiàn)了由于轉速指示波動使柴油發(fā)電機預潤滑泵頻繁啟停(>100 r/min時停,<100 r/min時開),導致燒毀發(fā)電機軸承預潤滑泵電機或其接觸器線圈的情況。
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.