The merry-go-round that explains the great blackout of April 28th in Spain
IMPORTANT NOTE: To better explain some things in a more accessible way, many details have been simplified. Below is a summary for anyone who wants to know more:
1. Power plant turbines don't necessarily have to operate strictly at 50 Hz; in fact, many don't. For example, the Ascó nuclear power plant operates at 1500 rpm (25 Hz), but since it has twice the number of poles on the rotor (4), the final frequency is 50 Hz, meaning it completes two cycles per revolution.
2. All the events narrated about what happened are true, except for those I mention in the video, which I am unaware of. Rumors have been circulating in recent hours that event 2 was caused by the shutdown of a nuclear plant, probably Almaraz, while event 1 was indeed caused by a photovoltaic park.
3. Around minute 7:40, it is stated that the frequency dropped and that the average frequency was lower. What propagates is not the frequency, but the power oscillations (phase angle, voltage/current transients). This is an oversimplification to avoid lengthening the technical explanation.
4. Nuclear power plant turbines do not normally rotate at 50 Hz, as they have two poles and operate at 1500 rpm or 25 Hz. This is a simplification to convey the message without providing a technical explanation, since it is effectively as if they were rotating at 3000 rpm (50 Hz) with one pole.
5. As mentioned below, neither residual current devices (RCDs) nor circuit breakers protect against overvoltages. This would be done by a varistor (for very short-duration high voltages) and a permanent surge protector, which most homes do not have today.
00:00 Introduction and Events
00:51 The Dance
02:22 The Protections
03:48 The Carousel
05:38 Inertia
06:33 Without Wheels
08:06 Sequence of Events
12:06 How Do We Avoid It?
13:38 The Motorcycle