sunkensheep

Joined 9 years ago

Karma
41
Submissions
8
Member since
Oct 27
Electronic / Telecommunications / Embedded Software Design engineer. Active in IOT, renewable energy and DSP areas.
View on Hacker News

Recent submissions

Comment · 7 years ago
Water is a bit less forgiving than steam, it has great resistance to changes in position or velocity. I suspect that closing the generator created a water-hammer, which physically or mechanically destroyed the machine.
Comment · 7 years ago
It's just "blackhat" SEO. Reminds me of a scheme in China where a company sold fake medicines and astro-turfed their way into appearing as a major supplier. So long as our view of the internet is governed by opaque algorithms with no oversight, gaming them will be profitable.
Comment · 7 years ago
Astounds me how anti-human organizations such as ALEC are granted such influence by Republican and Democrat alike in the USA. The fraud on the other hand, doesn't surprise me. Despite their power, these regulatory institutions seem more captured by vested interests and partisan politics than the public good they should be providing.
Comment · 7 years ago
Comment · 7 years ago
There can be issues with a line-commutated inverter or asynchronous generation (wind-farms might have both) if the fault level is too low (synchronous plant too small or too distant). More recent research has shown the benefits of adding grid support (reactive power control, fault response) to the control system of renewable generation.

In future I would expect renewable and storage elements to provide black-start frequency reference.

Comment · 7 years ago
To connect two regions, we align the phase of the two islands. As the voltage across our switch bank falls to zero, we close the switches. It's not a big difference from between synchronizing a generator. The phase is aligned by requesting small changes to generator output, and measurement is done by synchrophasor.
Comment · 7 years ago
The MCAS may not have been designed as an anti-stall system, but that doesn't necessarily mean it functioned according to design. The possibility for multiple activations integrates the control response, converting feedforward control into a closed loop (it will continue to act on the trim until the AoA decreases). Somewhere a decision has been made about a control system without requisite knowledge or understanding of the consequences, and this made it through design validation, testing and certification. That is highly disturbing, as there is no certainty that MCAS is stable in any circumstances where the pilot is making manual trim adjustment.
Comment · 9 years ago
$1.50 per day is about $45 per month, $80 per month would be 175% of income, so I'd hope that there was a second income earner in the family.

Live from the official Hacker News API

A modern reader for Hacker News · SvelteKit + Skeleton