Posted on 06/21/2004 2:32:44 PM PDT by Robert357
A transmission line failed in Arizona, then a substation relay malfunctioned, a major nuclear generating facility went off line and three other power plants went down like dominoes this past Monday morning. "This incident certainly had the potential to cascade out of control," said Gregg Fishman, a spokesperson for the California Independent System Operator. However, "the automatic systems that detect and react to under-frequency events worked as planned, reducing loads immediately," he said.
What could have been the Western version of last August’s blackout in the Northeast was averted last Monday when automatic systems performed as planned in response to a transmission line failure I Arizona and subsequent substation relay malfunction that caused several power plants to trip off line including a major nuclear plant in California. The sudden loss of power rippled throughout the Western Grid, but outages were short in duration ad limited to the Southwest and isolated pockets of California---Snip--
More than a dozen transmission lines all rated either 500 kV or 230 KV, in the area known as the Palo Verde hub tripped out of service at 7:41 am MST on June 14. The sudden loss played havoc with the frequency on the Western grid. ---Snip---
The Rocky Desert Reliability Coordinator, one of three WECC reliability centers that monitor the grid in real time directed APS to shed load to recover their “area control error”—the difference between load and resource. If ACE is negative, the utility is leaning on other sources for energy.
“Even though APS entered 500 MW into their load shedding program, the program failed to shed any load, but APS shed 200 MW due to induction motor loads that were lost,” WECC reported. Peterson said some electric motors automatically shut down when power frequency falls.
The California ISO provided APS with a fluctuating supply of emergency power, topping out at 800 MW, for two and one half hours until 10 a.m., said Fishman. When the incident occurred, said the grid operator’s spokesperson, the loss of generation from the southwest cause an immediate increase in north to south flow on the California-Oregon Intertie up near the boarder. Flow increased by about 2500 MW-and was significantly over its rated capacity.
Cal ISO was able to bring up additional generation very quickly, which not only reduced the flow on the C-OI to normal levels within 11 minutes, it also helped stabilize the frequency around the whole Western interconnection, “ noted Fishman. –snip-
The WECC initially counted about 30,000 APS customers who lost power. APS later reported 25,000 customers were affected for 20 to 45 minutes, and another 2,000 were out for about 90 minutes.
Pacific Gas & Electric reported 4,100 customers in the San Jose area-lost power for less than an hours. Als0 PG&E had 35 non-firm commercial and industrial customers that saw their power supply interrupted.
Tucson Electric Power shed power for 35,000 customers but restored them within an hour. Power supply was interrupted for less than 15 minutes to 1,000 SRP customers while 327 MW of interruptible load was dropped for a short time. Public Service Company of New Mexico reported 16,000 customers affected for 5 to 12 minutes. –snip--
(Excerpt) Read more at newsdata.com ...
With Palo Verde down, I expect the California will be even more "on the edge" for the next few weeks.
Looks like California avoided a major Blackout one week ago. Strange how I didn't see this covered in the media that was obsessed with Enron? Oh well I guess there isn't much politics in this!!!
The last thing we need in AZ in June is for the A/C's to stop running!
Actually switches operate in milliseconds to control the UV. No way could human intervention have prevented this. Good maintenance on sub-station equipment is the key.
Major league meltdown if it happened in Missouri. Fortunately, we have plenty of cheap hydro from Lake of the Ozarks and Truman Dam.
I'm glad Texas has its own power grid. You never hear about the Texas grid going down.
Whewww!
ping
ya and your neighboors will raise HE** with you for the eye sore in your yard.
My mother-in-law works at Palo Verde. She was off work last Monday when the system went down. I teased her that every time she's off work one of the grids goes down. She asked if it had been reported, but apparently the reason the grid went down was because a bird pooped on a line. Big bird, I guess.
They are already here. Thousands of them. Not in my yard exactly but close enough to keep the juice flowing in our neighborhood. If you look at the valley floor just below the snow on the peak you can make out the windmills.
Besides, the views are not all bad.
Heck, it's about 90 today in Reno, NV cannot imagine how hot it's gotta be in AZ!!!
Should be about 103 today. Although it is truth that low humidity helps you get tired of the phrase "it's a dry heat". So's the oven but it still cooks the chicken! lol
Maintenance by a utility? What's that?
Not the whole grid but let a bird land on a wire and it'll go out here every time. Don't get me started on the weekly tv cable service's "but it's sun spots" excuses.
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