What Is It For? (skip if desired)
It's been less than a decades since the Ilus system was cut off at its interstellar phase-gate, a few short years after the keidran were created and a disaster forced Sequoia R&DA to cut off the entire system to save humanity from their own mistake.
Our protagonist just got done getting marooned here and getting himself turned into a keidran. He's already fixed the tiny dyson swarm and gotten his cup of hot cocoa. Now he needs to fix the phase-gate and get home. Unfortunately the gate collapsed into a black hole with the mass of a small mountain and ate the phase-gate armature.
What Does It Do?
Basically, Ilus doesn't have the industrial might of the Terran system, and they can't import a replacement gate. So they have to jury-rig one with what they have. It runs on some yet-undiscovered quantum mechanics, and in short needs a large amount of power in a short window of time to be reopened.
Originally it had a system to do this easily, but it's gone and they can't make a replacement. With high-temperature superconductors and technology of such a caliber, even if its now second-hand scraps, how would you deliver thousands of peta-watts of electricity over the span of 3 to 5 seconds.
The machine would have dozens of jury-rigged hookups for 50 meter thick liquid-nitrogen-sheathed superconducting cables, and would operate at (relatively) low voltages, to minimize insulation issues.
The solution would just need to be single-use, frying itself it totally fine. Currently I planned on using some kind of superconducting rings that slowly build up a magnetic flux, to then use chemical explosive pumping to collapse the field in a blinding flash and with some luck, direct the energy flux into the machine through some seriously beefy cables.
Apart from an arbitrarily massive or unbelievably futuristic ultra-capacitors, or some handwavium-powered antimatter-to-electricity reactor, how would you approach such a problem?