As I type this (10 40 AM ) a little over a third of our mains is now inverter derived, about 30% from wind, and 5% from undersea links - French nuclear probably, and if the gridwatch website is to be believed about 6% from solar.
At the same time a lot of the spinning load from large industrial plants, cooling systems and so forth is now more likely to be variable frequency drive than the plain induction motor that turns generator during a phase shift it would have been.
I think it is quite credible that we have already lost half the inertia we had when the systems that control the grid were being designed, and the trend will continue - if we add a few GW of car charging load that will not be inertial either.
The frequency shift thing has an elegant and fail -afe simplicity, in that the phase shifts automatically cause current to flow from places with an excess of generation towards those with more load, so maybe we should continue to emulate it with the larger inverters at least until a clear alternative is available. It also allows things like the dynamic demand circuit, perhaps optimized better, to give smart load shedding within the appliance without needing any network connection and all the time delay and unreliability that entails.
As I type this (10 40 AM ) a little over a third of our mains is now inverter derived, about 30% from wind, and 5% from undersea links - French nuclear probably, and if the gridwatch website is to be believed about 6% from solar.
At the same time a lot of the spinning load from large industrial plants, cooling systems and so forth is now more likely to be variable frequency drive than the plain induction motor that turns generator during a phase shift it would have been.
I think it is quite credible that we have already lost half the inertia we had when the systems that control the grid were being designed, and the trend will continue - if we add a few GW of car charging load that will not be inertial either.
The frequency shift thing has an elegant and fail -afe simplicity, in that the phase shifts automatically cause current to flow from places with an excess of generation towards those with more load, so maybe we should continue to emulate it with the larger inverters at least until a clear alternative is available. It also allows things like the dynamic demand circuit, perhaps optimized better, to give smart load shedding within the appliance without needing any network connection and all the time delay and unreliability that entails.
