Point taken regarding use of the "load" terminology.įrom the responses provided, if I have understood correctly, it appears as though defects in AVR circuits would not normally have an effect on the governor, wrt kW sharing, unless there is common hardware/software? Jimmy Carter RE: Generator governor troubleshooting - AVR defects crshears (Electrical) 3 Mar 15 00:43 The AVR may have issues but it will not effect frequency or kW load sharing. The information given points to a faulty governor. The AVR will have an effect on the current but no effect on the kW sharing. As the prime mover drops below synchronous speed, the reverse power relay will trip the generator off-line and without the other sets to "lock" the frequency, the frequency will drop. If the governor starts to back off, the prime mover power will be less and less. If the governor opens too far both the kW input and output will increase (for parallel operation).Īs long as the generator is in parallel and has less capacity than the load on the plant, the frequency will be controlled by the healthy sets. KiloWatt output will never be greater than kiloWatt input and is controlled by the governor. This circulating current does not add to the loading except as a minor second order effect due to the increased I√R caused by the greater current. When two sources with differing voltages are connected in parallel, be they transformers or generators, a reactive current will circulate.
The KVA is related to the current as shown by the the ammeter and the KVA will never be less than the kW. Second, we must be sure that we understand what we mean by "load". how an AVR defect may affect the ability of the governor to maintain engine speed and consequently frequency)? RE: Generator governor troubleshooting - AVR defects waross (Electrical) 2 Mar 15 23:52įirst, a drop in frequency is a governor problem. I am aware that generally speaking the Governor will respond to kW load changes and the AVR KVAR load changes consequently could someone please explain the relationship between the two and provide some reference that I may be able to do some further reading into? Further to this could someone explain how a defect in one may affect the operation of the other (i.e.
However, noting I only have a general knowledge of generator control, I cannot fully understand how the operation of the AVR (or maloperation) would have an effect on the operation of the governor and visa versa. I undertand enough to know that there can be quite a number of causes relating to frequency excursions, surges etc. However, in a follow up report, it suggests that the root cause could be a faulty AVR. Initially the report suggests a faulty governor. The defect notice indicated that one of the DAs was load sharing eratically, continuing "to take on load or shed load when in parallel," and when not under load "frequency continues to reduce". When I press Reset button on MCP, only time of Alarm 3000 updates but not clear.I have been recently made aware of an issue regarding erratic operation of a diesel alternator governor (or so it was reported) on a shipborne diesel alternator, part of a plant of three (3) 480kW DAs. Now DB10.DBX56.1 = false but "Alarm 3000" still there and DB10.DBX106.1 = true (Emergency stop active) I wrote a small ladder which will set an memory bit if DB10.DBX56.1=true. I also checked if DB10.DBX56.1 becomes true and false in a short time. Signals are as I expected but "Alarm 3000" still there. button released and Acknowledge button pressed -> DB10.DBX56.1 = falseĭB10.DBX56.2 = true (when Ack. button released (Acknowledge button not pressed)-> DB10.DBX56.1 = trueĮmg. button pressed -> DB10.DBX56.1 = trueĮmg. I checked everything all of them looks ok.There is no emergency button pressed no door is opened.Įmg. System is Sinumerik Power Line 840D NCU571.4, PCU 50 I can't clear "Alarm 3000" Emergency stop.