4 ms·

Yeah. It's meant not to connect until sufficiently in sync. Running out of sync apparently results in the grid nudging the generator into sync, but here the dis

Yeah. It's meant not to connect until sufficiently in sync. Running out of sync apparently results in the grid nudging the generator into sync, but here the discrepancy was so large the nudge became a percussive encouragement of significant enough magnitude for the generator to permanently take a seat and reconsider. (that sentence was fun to write)

kn100 6y ago
It's useful to imagine this way: When a motor is forced to spin by some external influence, drawing more current out of it on the other end means it has to spin with more torque in order to maintain the same voltage. Here, the generators are connected together to supply power in unison. They must all be in phase with each-other otherwise the out of phase generator will find itself fighting with the other generators, and as beautifully demonstrated here will very violently lose the fight. You could describe this as a very cruel demonstration of destructive interference!
- a1369209993 6y ago
  Put another way: every electric motor is also a generator and vice-versa. If you induce the motor to absorb energy from the power supply rather than emit it, that energy has to go somewhere. As usual, when not specified, "somewhere" tends to mean heat, sound, and inelastic deformation of anything in relatively close proximity to the excess energy.
Animats 6y ago
Right. Here's a generator being synchronized.[1] The classic protective mechanism for this is big fuses. Classic manual synchronization of a generator involved three lamps, showing the voltage difference between the phases of the generator and the grid. The operator has to adjust the speed of the generator until all lights stop flickering and go out. Here's that being done with a desktop training setup.[2] Because this is a touchy operation to do manually, it's usually automated. However, there's no reason you couldn't have a hard wired interlock so that the breaker won't close until all three difference voltages are low enough. But it's so tempting to cut costs and put all that functionality into one convenient package. Like this one.[3]: The SEL-700G is the right solution for utility and industrial generator protection, with an autosynchronizer, flexible I/O, and advanced communications. It provides a complete protection and synchronization solution for synchronous generators, so you can eliminate the complexity and cost of standalone synchronizer packages. Integrating the synchronization capability into the generator protection relay provides the most cost-effective and reliable solution. The 5-inch, 800 x 480 color touchscreen display option allows you to directly set, monitor, and control your system, including up to five two- or three-position disconnect switches. A small form factor and multiple mounting adapters make it easy to upgrade protection without cutting or drilling existing cutouts. You can quickly integrate the SEL-700G into serial or Ethernet-based communications with IEC 61850 Edition 2, EtherNet/IP, the IEEE 1588 Precision Time Protocol (PTP), IEC 60870-5-103, the IEC 62439 Parallel Redundancy Protocol (PRP), Mirrored Bits communications, Modbus, DNP3, and other protocols. What could possibly go wrong? [1] https://youtu.be/FI_07YVS3tY https://youtu.be/FI_07YVS3tY [2] https://youtu.be/RGPCIypib5Q https://youtu.be/RGPCIypib5Q [3] https://selinc.com/products/700G/ https://selinc.com/products/700G/

kn100 6y ago

It's useful to imagine this way: When a motor is forced to spin by some external influence, drawing more current out of it on the other end means it has to spin with more torque in order to maintain the same voltage. Here, the generators are connected together to supply power in unison. They must all be in phase with each-other otherwise the out of phase generator will find itself fighting with the other generators, and as beautifully demonstrated here will very violently lose the fight. You could describe this as a very cruel demonstration of destructive interference!

a1369209993 6y ago
Put another way: every electric motor is also a generator and vice-versa. If you induce the motor to absorb energy from the power supply rather than emit it, that energy has to go somewhere. As usual, when not specified, "somewhere" tends to mean heat, sound, and inelastic deformation of anything in relatively close proximity to the excess energy.

Animats 6y ago

Right. Here's a generator being synchronized.[1] The classic protective mechanism for this is big fuses. Classic manual synchronization of a generator involved three lamps, showing the voltage difference between the phases of the generator and the grid. The operator has to adjust the speed of the generator until all lights stop flickering and go out. Here's that being done with a desktop training setup.[2] Because this is a touchy operation to do manually, it's usually automated. However, there's no reason you couldn't have a hard wired interlock so that the breaker won't close until all three difference voltages are low enough. But it's so tempting to cut costs and put all that functionality into one convenient package. Like this one.[3]: The SEL-700G is the right solution for utility and industrial generator protection, with an autosynchronizer, flexible I/O, and advanced communications. It provides a complete protection and synchronization solution for synchronous generators, so you can eliminate the complexity and cost of standalone synchronizer packages. Integrating the synchronization capability into the generator protection relay provides the most cost-effective and reliable solution. The 5-inch, 800 x 480 color touchscreen display option allows you to directly set, monitor, and control your system, including up to five two- or three-position disconnect switches. A small form factor and multiple mounting adapters make it easy to upgrade protection without cutting or drilling existing cutouts. You can quickly integrate the SEL-700G into serial or Ethernet-based communications with IEC 61850 Edition 2, EtherNet/IP, the IEEE 1588 Precision Time Protocol (PTP), IEC 60870-5-103, the IEC 62439 Parallel Redundancy Protocol (PRP), Mirrored Bits communications, Modbus, DNP3, and other protocols. What could possibly go wrong? [1] https://youtu.be/FI_07YVS3tY https://youtu.be/FI_07YVS3tY [2] https://youtu.be/RGPCIypib5Q https://youtu.be/RGPCIypib5Q [3] https://selinc.com/products/700G/ https://selinc.com/products/700G/