I have challenge in synchronizing generators, the two generators are of equal ratings in all the parameters. the generator make and ratings is 1500 KVA cat generator.

the challenge i am having is this, when i run the generator single without synchronizing, it operate normal, but when i run it on synchronizing, i immediately the two generator merges together, a current of 786amps will generated without picking load.

my question is what is necessary for the high amps and how can it be eliminated so that i can have a smooth synchronizing, Thank. best regard.

Udeme Okosi.
[email protected]

 

The Summary for this thread seems to disagree with the body of the thread. At least, something doesn't quite add up.

Most importantly: When did this problem start? Has it been possible in the past to smoothly synchronize the two machines, but recently or suddenly it has become difficult or troublesome?

There are two generator-sets of equal rating (a generator-set is the prime mover (Caterpillar diesel engine) and generator). The nature of the load is not understood--do these generators normally supply a "local" load which is not connected to a larger grid? In other words, do the gen-sets operate in what's commonly called "island" mode--independent of other gen-sets and a larger transmission and distribution system? Is each gen-set capable of supplying the needs of the load on its own--without an assist from any other gen-set?

Are the two gen-sets roughly the same age and do they have the same control system (sometimes called a governor)?

Do you synchronize (parallel) the two gen-sets when you are going to "switch" gen-sets (take the one currently in service out of service, replaced by the one being brought on line--synchronized to the one currently supplying the load)?

Is there some kind of load-sharing controller/scheme in place between the two gen-sets? Something that senses the load and does some kind of load-splitting between the two gen-sets by sending signals to both gen-set control systems (the prime mover control system)? It could be another separate control system, or it could be a special communications link between the two prime mover control systems. Or, are the two generator set control systems completely independent of each other, with no over-riding control system and no communication link between them?

When the two gen-sets are synchronized, what governor mode is each gen-set operating in? Isochronous control/mode? Droop control/mode?

In the Summary you state a NO LOAD condition, but in the body of the thread you talk about no INCREASE in load? So, the running gen-set is supplying some load at the time the incoming gen-set is synchronized? What is the load (in amps) on the running gen-set just before synchronization? What is the load on each gen-set just after synchronization (in amps)? Does the load on the running gen-set suddenly shift to the incoming gen-set on synchronization? How much of the load on the running gen-set shifts to the incoming gen-set on synchronization?

What happens to the frequency of the gen-sets when they are synchronized?

What happens to the VArs on each machine when they are synchronized?

Does this happen when Gen-set #1 is running and Gen-set #2 is synchronized to Gen-set #1 <b>AND</b> when Gen-set #2 is running and Gen-set #1 is synchronized to Gen-set #2? Or only when one of the gen-sets is running and you synchronize the other gen-set to that one? In other words, does the same thing happen to both gen-sets when they are synchronized, or only when one of them is synchronized to the other?