![]() What kind of governors on the prime movers? OK, an older system, still could use some more detail, RE: Synchronizing 2 generator problem, pls help michelin3x (Electrical) The bulk of my experience is with Woodward based controls, like the DSLC and MSLC, but they are expensive and mostly used for larger units, now with the EasyGen and others like Basler, Dief, ComAp and DeepSea, I see lots of systems using these types of controls on smaller units.Ĭould you provide some details about your installed system? Is this a new problem on a new system, or a new problem on a system that has been in service for awhile? Any work done on the engines, generators or controls if this is an existing system before this problem occured? Not easy but can be achieved with newer controls and well done setup and testing. We are also seeing a large number of mostly standby systems that require very good sharing, voltage and frequency control with multiple units on the bus and no bus load. I haven't done a new installation using cross current for VAR share for a couple of years, same goes for using droop for real power sharing. With the current offerings of really nice controllers at much lower prices these days, most units I see are using active real and reactive load sharing. I just had a similar situation with units using Woodward Load Share Modules over the engines electronic governors, the load share lines were reversed at on section. Since these seem to be smaller size units, he may have genset controls like a Woodward EasyGen or ComAP. Maybe the OP could actually describe what he is using for the governors, how real power sharing is being done (droop, isochronus using a real power controller, or a combination type system)? How is the system doing VAR sharing? Is it in voltage droop, cross current, or using some form of reactive power controller? Jimmy Carter RE: Synchronizing 2 generator problem, pls help catserveng (Electrical) 31 Jan 13 22:05Ī lot of good direction here, but most assumes this system may be real power sharing in droop and VAR sharing in cross current. The current is dropped across a resistor and the resulting voltage is used to bias the sense voltage in the AVR so that the VARs are shared. This will put it in phase with the voltage across A and B phases. The cross current schemes monitor the current in C phase and any reactive current will be at 90 degrees. The characteristics and settings of the governors will determine the kW load sharing between the machines.Īny voltage difference will upset the VAR sharing of the machines. Too much voltage difference will drive circulating reactive currents between the machines. Heed the other posters Put some load on the set before trying to sync a second generator.Ī voltage difference between the sets will upset the VAR sharing. If I understand your description, the incoming set is running a little slow and is being motored slightly. This is negligible and we are going to ignore it.When syncing a generator, the incoming set should be running a little faster to pick up some load and prevent motoring the incoming set. ![]() *Okay, actually at max power output more current is going to the speaker and DC current goes down very slightly. You can't "bias" an amp as Class A, you have to actually "operate" it in Class A. It's about transformer behavior and the reflected impedance of the speaker (which changes radically through its frequency response), the screen supply, the driver circuit and its output crossing the zero point. This isn't just about how much current you run through the quiescent tube. The biggest mistake people make is talking about "biasing an amp in class A" rather than operating the amp in class A. There are no formally defined classes of operation at that point, there is only what the amp is doing. And here we get to why it is kinda silly to even argue about class of operation here, we are regularly pushing the amp into an overdriven condition. ![]() ![]() That is the basic and fundamental definition of Class A. If the amp is truly operating in Class A, then there IS no bias current change on either tube at any time*. both tubes are at 100% at idle, when one is at 125% the other is at 75%, the total current draw remains constant, the bias voltage doesn't change" Here's an example: "Think it through and you will see why. There is so much misinformation, some deliberate, and even more simple and honest misunderstanding of what is a very, very complex phenomenon that it becomes almost impossible. This is why I really do not like the semi-technical discussions of class of operation. ![]()
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