Dear all,
Manufactures of MV motors recommend 70% to 85% of Un (norminal voltage) for undervoltage protection.What factors were considered when determining the undervoltage protection setting and is there any calculation that can be done from first principles to determine such setting value...
Hi all,
Our power plant was initially designed for base load operation but due to some reason we were then required to change operating regime to two shifting (cyclic operation). This meant increased barring hours, increased number of stop starts which had bad impact to our rotors and all rotor...
Hi
A question below:
1. what are the advantages of operating stator water chemisty at low oxyen elevated PH. I recently experienced high copper from the water, oxygen, ph, conductivity levels all ok. iron slightly out.
2. what is the safest dew point when operating h2-water cooled machine? is...
Hi all,
I have a question regading 700MW generator rotor.
1. What kind of damage will the generator experience during switch on to stand still (SOS). I have seen pictures of rotor which suffered SOS but not sure exactly what else could go wrong?
2. If say 3000 rpm rotor is turning at lower...
Hi all,
I have had a quite number of incidents were the rotor pole A to pole B connector flexible were found cracking progressively due to stop-start operation. I have reaseached quite number of on-line tests and off-line test that can detect this problem. Thus far the stray flux test is the...
Hi
What is the impact of conducting MVAr capability test on the generator to prove the the ability of MVAr expoting to the system against the OEM supplied capability diagram. I will push the machine to the rated MVar and keep it constant for about three hours during that time verything must be...
Hi
Can someone please explain what effect will barring have on the rotor of 600 to 800 MW machine, will increasing or reducing the barring speed reduce the probability of fretting on the rotor slots etc?. With a two shifting station alot of our machines sees a lot of stop-start mode of...
Hi, Please questions below:
1. I am responsible for the performance, maintanace and condition monitoring of six 600 to 700MW generators.I have since observed that at higher MW and MVar the stator core temps are increasing proportionally but some other sections on the core, particularly the end...
