S
Hello everybody,
In our installation we have a two shaft GE gas turbine (PGT10). The control system is Mark V simplex architecture (<R> core only).
The HP shaft has got three speed sensors (Magnetic pick up), called TNH1, TNH2 and TNH3 connected to <R> via the QTBA card.
During the start up sequence (from0% to 65% HP speed) all the three values TNH1, TNH2 and TNH3 in MK5 HMI are identical. However, above 65% HP speed, TNH1, TNH3 increase normally to full speed and TNH2 stays at 65 % and then drops below this value down to 39%
What we did?
1) We checked the wiring, changed the speed sensor the problem still persists.
2) We have used the function generator to simulate the HP shaft speed. We have connected the function generator to TNH1, TNH2 and TNH3 in parallel directly in the QTBA card (this eliminates the sensor and/or wiring problem), then we increased the frequency from zero all the way up, we noticed the same phenomena, the TNH2 can not follow TNH1 and TNH3 when the speed is above 65%.
3) We have changed the QTBA cad but the problem still the same.
Has someone encountered this problem or can someone help us to solve this problem?
Thanks
In our installation we have a two shaft GE gas turbine (PGT10). The control system is Mark V simplex architecture (<R> core only).
The HP shaft has got three speed sensors (Magnetic pick up), called TNH1, TNH2 and TNH3 connected to <R> via the QTBA card.
During the start up sequence (from0% to 65% HP speed) all the three values TNH1, TNH2 and TNH3 in MK5 HMI are identical. However, above 65% HP speed, TNH1, TNH3 increase normally to full speed and TNH2 stays at 65 % and then drops below this value down to 39%
What we did?
1) We checked the wiring, changed the speed sensor the problem still persists.
2) We have used the function generator to simulate the HP shaft speed. We have connected the function generator to TNH1, TNH2 and TNH3 in parallel directly in the QTBA card (this eliminates the sensor and/or wiring problem), then we increased the frequency from zero all the way up, we noticed the same phenomena, the TNH2 can not follow TNH1 and TNH3 when the speed is above 65%.
3) We have changed the QTBA cad but the problem still the same.
Has someone encountered this problem or can someone help us to solve this problem?
Thanks