柴油發(fā)電機(jī)組轉(zhuǎn)速測(cè)量保護(hù)系統(tǒng)的工作原理：

　　轉(zhuǎn)速是柴油發(fā)電機(jī)設(shè)備中最基本、最重要的參數(shù)之一，起動(dòng)時(shí)的點(diǎn)火轉(zhuǎn)速、運(yùn)行中的轉(zhuǎn)速調(diào)整、超速時(shí)的停車保護(hù)、甚至負(fù)荷的大小也能從轉(zhuǎn)速的大小上得到體現(xiàn)，因此轉(zhuǎn)速測(cè)定是柴油發(fā)電機(jī)監(jiān)控保護(hù)的基礎(chǔ)。一般柴油機(jī)中轉(zhuǎn)速的測(cè)量有二處，一是主機(jī)轉(zhuǎn)速的測(cè)量，二是渦輪增壓器轉(zhuǎn)速的測(cè)量。

　?。?/span>1） 傳感器。傳感器是一個(gè)近程感應(yīng)開關(guān)，不通過接觸就可以工作。它由振蕩器、觸發(fā)器及放大器組成，通過振蕩器電路線圈產(chǎn)生一交變電磁場(chǎng)。在金屬導(dǎo)體接近傳感器時(shí)交變磁場(chǎng)就會(huì)發(fā)生變化，振蕩器的輸出電壓隨之發(fā)生變化，頻率也發(fā)生變化。主機(jī)轉(zhuǎn)速測(cè)量的傳感器共有4個(gè)。2個(gè)測(cè)量轉(zhuǎn)速并經(jīng)速度變送器在CMR盤或OCW盤顯示轉(zhuǎn)速，另外2個(gè)供調(diào)速器使用。

　?。?/span>2） 速度變送器。將傳感器傳輸來的頻率信號(hào)轉(zhuǎn)換成4～20 mA的電流信號(hào)，傳送給轉(zhuǎn)速表。

　　（3） 轉(zhuǎn)速表。顯示轉(zhuǎn)速。

The working principle of the speed measurement and protection system for diesel generator sets:

Speed is one of the most basic and important parameters in diesel generator equipment. The ignition speed during start-up, speed adjustment during operation, parking protection during overspeed, and even the size of the load can also be reflected from the speed. Therefore, speed measurement is the basis of diesel generator monitoring and protection. There are two ways to measure the rotational speed in a typical diesel engine: one is to measure the engine speed, and the other is to measure the turbocharger speed.

(1) Sensors. The sensor is a proximity sensing switch that can operate without contact. It consists of an oscillator, a trigger, and an amplifier, which generate an alternating electromagnetic field through the oscillator circuit coil. When a metal conductor approaches the sensor, the alternating magnetic field will change, and the output voltage of the oscillator will also change, along with the frequency. There are a total of 4 sensors for measuring the speed of the host. Two measure the speed and display it on the CMR or OCW panel through the speed transmitter, while the other two are used for the speed controller.

(2) Speed transmitter. Convert the frequency signal transmitted by the sensor into a 4-20 mA current signal and transmit it to the tachometer.

(3) Tachometer. Display the rotational speed.