Power Grid Frequency Stability

This cluster centers on discussions of electrical power grid operations, focusing on frequency control via spinning generators and inertia, supply-demand balance, and challenges from renewables like solar and batteries lacking inherent stability.

➡️ Stable 1.0x Science
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Keywords

AFAIK US MW IBM stackexchange.com DC PV TX EEA AC grid frequency generators power voltage load inertia generator spinning solar

Sample Comments

Hydrocarb0n Apr 28, 2025 View on HN

Harder mostly, See the frequency is set by huge rotating masses in the form of generators, and when the supply and demand is matched the frequency and voltage are stable, when demand dramatically increases it pulls the frequency and voltage down, which is effectively slowing the generators down as load / magnetic drag increases with current drawn. Having large inertial masses spinning actually helps smooth out frequency changes. whilst large solar farms can and do syncronise with the grid,

Dirtier power generation doesn't work because physics. Frequency gets too high (a few Hz or so), turbogenerators/turbines blow up. Frequency gets too low, resonances destroy them. Frequency shifts quickly, massive torque and current spikes ensue. Load is dumped, frequency ramps up quickly and voltage rises very quickly. There are a number of control and monitoring systems in a power plant which ought to prevent these from happening, but in the bigger picture this means that grid power

threatripper Jan 20, 2022 View on HN

There is not enough information in the article to actually understand what they mean. Spinning the generator a bit faster or slower is not the problem. They should always be operated within their limits, so that is not the problem. The problem is that when one region is overloaded it loses synchronization with the rest of the grid and that causes issues. Before that happens some regions are shut off (local controlled blackout), the grid is split up and some power plants even go offline.In gen

johngladtj Feb 9, 2025 View on HN

That's not how the power grid works

markus92 Mar 2, 2024 View on HN

That's exactly how it works! Grid frequency is determined by the speed of all turbines connected to it. They lost a bit of inertia due to energy being taken out of the system (higher demand than supply of power), so they slowed down, the grid frequency lowered and clocks started running behind. To get the frequency back, gotta generate a bit more energy to speed all the turbines back up.

corty Jan 8, 2021 View on HN

Batteries maybe. Allowing "dirtier" non-50Hz power would make things worse, power plant turbines are optimized for 50Hz, different frequencies get inefficient quite fast. So your generation will shrink the lower you go. At the same time generators running at different frequencies will work against each other. At the same time machines will pull the frequency down even further, landing you in a vicious circle that forces the frequency toward 0Hz. No choice but to cut power before you da

lykr0n Dec 19, 2017 View on HN

Out of the wall in the US we get 120v @ 60Hz (elsewhere is 220v to 240v @ 50Hz). If the load becomes too high, the frequency starts to drop.Inductive (motors and such) loads do not fare well when the frequency drops which can cause serious damage. Capacitive or Resistive loads can handle a bit more fluxation, but the whole system is built around the idea that voltage and frequency are fixed. Fluxations can cause grid failures, brownouts, or damage to consumer electronics.AFAIK, that is pre

jnsaff2 Jan 26, 2021 View on HN

Yes indeed, inverter based generators (solar and batteries) don't have any inertia. But as long as the grid is still AC the frequency will be the same and the inverters would need to compensate internally. Especially with solar where a cloud going over a solar farm can easily knock off a few MW in seconds the volatility of the grid will increase and need for storage (batteries, hydro, etc) alongside Demand Side Response is getting much bigger.

tibbydudeza Feb 18, 2021 View on HN

My understanding is the entire grid needs to be at a stable frequency of either 50 or 60 Hz (affected by demand) , if a generator goes out of sync/phase you are going have major trouble.Bringing up a grid from scratch from a total blackout scenario is such a time consuming process so you rather throw consumers off with no warning even in the coldest winter imaginable.

7952 Sep 1, 2019 View on HN

Is grid frequency not a good enough signal in its own right to increase production?