[BC] 3 phase to single phase conversion - a sneaky, perhaps unethical solution

[PeterH]

On Feb 13, 2009, at 3:24 PM, Mike McCarthy wrote:

> Adding or dropping a 100KW load isn't one of those....  We're  
> talking 100MW and higher...like plants with larger super  
> temperature heaters/furnaces used in metal/glass forging/fabrication.

It all depends upon how stiff  the transmission or subtransmission  
system is, and how much "spinning reserve" a system has.

At LADWP, when the Sylmar Earthquake hit us, and 1,400 MW was  
instantaneously lost due to the destruction of the Sylmar Converter  
Station, there was just a tiny blip, and no interruption, at my  
residence in the Brentwood District of L.A., about 20 miles from the  
Converter Station.

L.A. is encircled by a very stiff transmission system which multiply  
interconnects the largest stations, the so-called receiving stations  
(because these are on the transmission system, not on the  
distribution system), with the interconnections being, variously, 138  
kV or 230 kV, and some of those are three to five circuits in parallel.

A 230 kV line can handle 1,000 MW for a short term, certainly long  
enough for another route to be found by the dispatchers.

And, there are 230 and 500 kV ac and 1,000 kV dc coming into L.A.  
from multiple points.

Not much in the way of high-powered broadcast on the L.A. system.

Only two of the region's 50 kW AMs, 710 and 1540, but all of the ex  
Class III-A 5 kW AMs (except 1150, which moved out, and is now 50 kW,  
but the old 5 kW site remains for auxiliary purposes). All the other  
50 kW AMs, and most of the FMs, and all of the TVs are in SCE  
territory, but LADWP is an SCE interchange partner, and LADWP has, by  
far, the stiffest transmission and subtransmission systems in the area.