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Sunday, August 30, 2009

2nd Addendum to the Fireman's Rant on Drivers

As I keep stewing about stuff, more bloggable rant material percolates to the surface.

This is the second follow-up to the original Fireman's Rant on Drivers. If you haven't read the rants yet, follow the above link and then also check out the first addendum, and then come back.

Several days ago, I was on a traffic control detail, assisting the Sheriff's Office. The absurdity of what happened has actually become so common that it didn't even register as worth bringing up here. That means that dumb people are doing this so often that it must be ranted about.

Thanks to Firecap5, who also suffered a recent similar event on the job, it clicked. If you have not already visited his blog, "Not trained, but we try hard!", do yourself a favor and add it to your list.

So here we go.

WHAT PART OF 'CLOSED' DON'T YOU UNDERSTAND? When my BRT is parked SIDEWAYS, blocking the ENTIRE road, and sits behind a line of EIGHT smoky traffic flares, you might want to entertain the notion that something is going on up there and that your presence - particularly if you bring your vehicle along - is not welcome.

When you see a line of cars stopped in the road, and flashing red lights and BRTs in their way, you have two intelligent choices: (1) Wait in line with them. (2) If safe to do so, turn around and go a different way.

Do not feign to be offended at my incredulous reaction to you if you instead choose the unlisted option (3): Pull into the empty lane for oncoming traffic and approach the roadblock because you're special. Do not entertain the hope that I will be sympathetic to your tantrum when you ask if the road is really closed and I look at you, the blocking BRT, the flares, the 'STOP' paddle in my hand, the line of cars managing to wait patiently, whatever activity is visible up the road in the way, and then back at you to tell you "yes, believe it or not, the road is closed". Do not be surprised if a member of the Sheriff's Office or City PD pulls you over for reckless driving after you turn around and peel out in anger after I answer your next question (well, can I go through anyway?) with uncontrolled cackling, managing a "no" between fits of laughter. Good Lord, I cannot believe you are allowed to vote! We shouldn't even be obligated to share our AIR with you!

FIRE LANES. NOT JUST FOR FIRES. It's actually a good idea to leave those open for all emergencies. If you are too ignorant to notice the sign that says NO PARKING FIRE LANE, those driving laws and standards people have gone the extra mile for you and painted the curb RED to bring to your attention that you should not park there.

I'll give you the benefit of the doubt, that you don't know what the fire lane is for. Remember, BRTs are heavy, large, and sometimes difficult to maneuver. When we are trying to get to a place where there might be, oh say, a fire, with, maybe people trapped or something, we'd prefer a nice and clear path into where the problem is. That's what the fire lane is for. We also use the fire lanes to get quick access to medical emergencies. So if your loved ones were trapped in the proverbial commercial fire while shopping, or suffering cardiac arrest at the restaurant, I suspect you'd be unhappy with someone slowing our response by parking in a fire lane right? And you won't do it anymore, either, right?

I'll give one pass on this, against my better judgement. IF you stay in your vehicle, and IF you do not turn off your engine, and IF you roll down your windows so you hear approaching sirens, and IF you pay full attention to your aurroundings 360° for approaching emergency vehicles not sounding sirens, and IF you are not otherwise blocking traffic, and IF you are not blocking visibility for pedestrians trying to spot traffic around you, then I am personally, just barely, conditionally OK with you briefly sitting in a fire lane. The moment you sense trouble, hear sirens, or see us or my EMS and/or law enforcement brethren, it is time to move. My brothers in blue are still quite likely to ticket you for this even if you followed all my rules, because it is still clearly illegal beyond any debate. Saying 'Grumpy said it was cool' is no defense. You know... sorry, I made it complicated. Scratch this whole paragraph. Just don't do it.

This also applies to parking in front of fire hydrants.

If your vehicle is in the way in a fire lane or other spot you should not park in our way, and the situation is dire, I may very likely push your vehicle out of the way with my BRT. If you're lucky, we might be able to work around (or through) your vehicle, but you'll have to wait until we're done. You will be responsible for the repair bill for your vehicle, the repair bill for the BRT, any and all traffic fines, and possibly be held liable for delays in delivering medical care or fire suppression/rescue.

I leave you with some examples. And yes, that sign on the upper right of the first picture reads NO PARKING FIRE LANE.



Just stay out of our way. Thanks.

Thursday, August 27, 2009

Go Away, You're Bothering Me

It sure did get quiet around here. The tutorials have put y'all to sleep I guess. Sorry.

Seriously, I would like to know if they are helpful, interesting, or useless... a little feedback to help me shape how I do this would be welcomed if you have something to say about it. More pictures? Less rambling? Door prizes? Let me know....

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Like on fire scenes, any time you have so much as a moderately interesting incident at the power dispatch center, rubberneckers tend to appear. It is always amusing to me when the local distribution feeder to the control center trips out. We have hundreds of feeders on the system, each serving roughly anywhere from 500-2,000 customers in small pockets. We get feeder trips all day long for a variety of reasons: squirrels, storms, mylar ballons, traffic accidents, kites, tree branches. Dispatchers don't get excited about them, because.... that's what we do. But by golly if the feeder serving the dispatch office goes.... all these people show up, wanting to know what is going on. Cue the dramatic action soundtrack... our feeder tripped! Do not panic!!

Some dispatchers tolerate this. I do not. I stand up and tell them that unless I requested their presence, they need to leave the control room. Now. Rank and office means nothing. I am the Dispatcher, I am In Charge. Get out. Crap, guys, it's just a feeder. Where were you during the first five feeder trips today? It's not as if I need absolute quiet to restore a feeder or that it is any kind of particularly scary task... I can do feeder restorations practically in my sleep. It's the principle, though. Go away, you're bothering me.

Unlike the fire department, some more complicated incidents also tend to attract supervisor/manager-type rubberneckers who want to hover behind you, often to give unsolicited advice or even interfere with your work as they attempt to 'help'. They upgrade from simple rubberneckers for those feeder trips, to overzealous helpful citizens pulling another attack line off your engine or dumping your trauma kit out for you so you can 'see stuff better'.

Like on your fire scenes, this is usually unwelcome.

Ummm, make that pretty much always unwelcome.

In years past, even up to the 2003 Northeast Blackout, some investigations revealed that there were still some dispatchers who felt they couldn't act to save their system without some sort of supervisory approval. Such as.... let's say you suddenly lose a major power plant, making it impossible to meet customer demand. The system is sagging and approaching collapse. The solution is to immediately black out a portion of your system to restore the balance, in order to save the rest of it. But these guys, for whatever reason, felt like they had to get approval from a boss. You've sometimes got just seconds to save your system... it is the wrong time to call a boss. Saving the system in seconds is exactly what we're here to do, it kind of defeats the purpose if you have to get approval to blow your nose first.

If they do not heed the call to Get Out Now, there is the Level 2 Deterrent:

I get up, step away from the console, roll the chair to the 'helpful' boss and state "I understand that you are taking over this restoration and relieving me of duty. I'll be in the kitchen/bathroom/cafeteria, please send word when you're ready to turn control back to me."

I have used this exactly once, and the boss-type person skittered off. Word got around, I never had to do it again. If only some of these other guys would pull out their big guns, the bees would stop buzzing around their heads during incidents. Oh well.

The industry rules, enforced indirectly by the federal government are clear: The Dispatcher is IN CHARGE. Unless forcefully relieved of duty or fired. And when it is deer-in-the-headlights time, bosses who don't mind peppering you with "help" from the shoulder generally don't feel like instead stepping into the road to take over.

--------------

One last similar amusing event for your pleasure.

Beeeeeeep! Oh look, a feeder trip. It is after hours, so the rubbernecking problem is greatly reduced. The feeder recloser tries to pick it up again, fails due to a sustained fault, and locks the feeder out. Following our typical procedure, I wait a minute, for the charred squirrel carcass to fall away, and try the feeder manually one more time. Pop, out again. OK, time to call out a trouble crew.

I pull out the callout list and find the on-call guy's info. Before I can dial, however, my phone rings in. The following conversation ensues:

Grumpy Dispatcher: ECC, Grumpy.
Important Vice President: Hey yeah, this is Power Company Important Vice President. Hey, my lights are out here.

Now, our direct-dial line is not a public line. We have a customer service department who screens and funnels calls so we dispatchers hear about a problem once instead of fielding all the hundreds of calls. You have to know someone or be someone to have our direct dial line. Obviously, I am pretty sure Important Vice President is on this tripped feeder.

GD: Hello Mr. Important, what's your address?
IVP: 4624 Expensive Lane
GD: Yes sir, the feeder for your area is open.
.....(3-4 seconds of silence).....
IVP: Well, do you know why? Do you know what happened?
GD: No, sir. It just tripped, I don't know the cause yet.
.....(more awkward silence).....
IVP: (getting impatient with me) Well, uh, what are you doing about it??
GD: Nothing at the moment.
IVP: (indignant!) What? Why not?!
GD: Sir, I am on the phone, talking to you.
.....(sharp intake of breath, then loud silence).....
IVP: Hey, then. OK, I'll let you get back to it. Um, thanks.

That VP never called me on the desk again.

Tuesday, August 25, 2009

Tutorial 3 - Generation Supply, Control and Scheduling


Onward. I hope someone is learning something. I know that I am learning that I ramble too long about stuff.

So we know that electricity is produced exactly as it is consumed, and we know that power companies are tied to each other. So who pays for what sources of electricity and how does it get where it was supposed to go?

We'll build this in steps, from simple to complicated.

Let's back up and pretend we have an isolated, 'islanded' power system with miraculous stability due to one very responsive and large hydroelectric (water/dam) generator, and its own customer load, not tied to any neightbor systems.

As demand rises and frequency falls, the Automatic Generator Control (AGC) sees the frequency decline, recognizes that demand is greater than supply, and automatically directs the hydro plant to increase output. As demand declines, frequency rises, AGC backs the hydro off. Simple.

Let's add another power plant, a coal-fired thermal unit. Steam plants like this are typically not as fast-responsive as hydro, but can be cheap to run at large volumes. The AGC is made a little more intelligent by telling it how fast the steamer can move up and down compared to the hydro, and also by telling it how much it costs per Megawatt (MW) to run them.

The hydro is cheaper, but not by much. Also, steamers have limits on how far they can go down before they become unstable (perhaps 30% of their overall capacity), and their cost per MW increases as overall output is reduced and efficiency suffers. AGC also knows how to adjust the price on the steamer depending on where it is loaded.

Even though hydro is slightly cheaper to produce, it is better for the system as a whole to keep it loaded in its middle range so that it can respond quickly up or down to changes in demand. Better to have a stable system with a slightly higher cost than an unstable system with slightly cheaper power. AGC tries to keep the steamer loaded at its most efficient output, typically around 90-95%. For minor fluctuations in demand, AGC directs the hydro to jockey around and stabilize the frequency. However, if demand drops faster than the hydro can move, a threshold is reached where AGC decides to push down the steamer as well in order to get back to 60.00Hz. Once this is done, AGC moves the hydro and steamer in opposite directions to load up the steamer again while keeping the frequency stable.

Now expand that concept to include all power plants in a given power company's system. Smaller co-op and municipal systems may only have a handful, while the super-large utilities often have more than 100 generation sources. Their AGC applications know which units can move how fast, what they cost, and can juggle them on the fly to keep costs down while maintaining stability. Readings are taken and responded to every four to six seconds to maintain stability.

OK. Next step.... add a power line between two power companies. They are now synchronized and have the same frequency.

When frequency declines because overall demand is higher than overall supply, how do we know where the demand is and hence whose power plants should respond to fix the problem?

A metering device is placed on the power line to measure the flow of electricity across the line. If the two power companies do not have a transaction of electricity scheduled at the given moment, this one power line between them should be controlled to have no flow. So, the meter's output is provided to the all-knowing, all-controlling AGC widgets on both ends. Now not only is the AGC trying to control to 60.00Hz, it is also trying to keep the shared connecting power line at zero. If it sees the power line moving 100MW out of its area, it should direct its own power generators to back off a collective 100MW. Likewise, the AGC widget on the other side should see the 100MW coming in, realize it isn't meeting local demand, and crank up its own resources 100MW to fix the balance. After that, it is just math. If the companies agree to a transaction for 50MW, the AGC widgets will do their thing while keeping the line at 50MW in whatever direction is intended.

OK, next step.... add multiple power lines between these two companies.

No problem. The net sum of the flows of all of the power lines between them are collected. Let's say they have three power lines between them. Due to the physics oddities of resistance, distance, voltage, etc, the lines probably do not have equal flows, but you simply take the sum total and add them up. This total goes to the AGC widgets, and generation is moved accordingly.

OK, next step.... add multiple power companies with multiple power lines going everywhere.

Instead of adding up the sum total of the power lines between you and each individual neighbor, you instead take the grand sum total of all power lines connecting you to all of your neighbor power companies. You then also add up the grand netted sum of all scheduled transactions between you and your neighbor companies. As long as the single net sum of all actual flows matches the single net sum of all scheduled transactions, and frequency is 60.00Hz, you're good.

When power companies decide to buy or sell power, and run up or back off their units, it is almost always in consideration of which resources are cheapest.

Bear with me, math-phobics. Here's your schedules with your four neighbors:

Metropolis Power & Light: Selling 100MW to them
Gotham Water, Light and Power: Selling 50MW to them
Sim City Electric Co-Op: Buying 200MW from them
Pleasantville Power: Buying 100MW from them.

Selling 100 and 50 (150 out)
Buying 200 and 100 (300 in)
Net of all deals is 150 in. The AGC widget is informed of this.

In "real time", the flows on all the power lines connecting you to your neghbors are measured every four to six seconds, and the net sum is calculated and sent to the AGC widget. As long as frequency rides at 60.00Hz and the net sum of all the lines connecting you to your neighbors equals 150MW into your system, it's all good. Your AGC fixes demand/supply problems determined to be inside, and more or less ignores demand/supply problems outside.

Well kind of. AGC systems do see external supply/demand problems and automatically take steps to help (one of the main benefits of an interconnected grid) but we've gone far enough today, that is a subject for another time.

What we learned: (1) Different electric generation resources have different costs, and power companies take steps to generate electricity as cheaply as possible while remaining stable. (2) AGC is yet another acronym requiring the Grumpy Dispatcher to plan on putting up a glossary, 'cause we can all tell there's more of those acronyms coming. (3) Power companies are able to provide energy for their consumers by generating or purchasing electricity and it actually is possible to track what it costs to do that in each system. (4) Dang, this stuff is getting complicated and should be made more entertaining. More cowbell, please!

(Click this link to see all posts tagged "tutorial")



Observations on Organized Camping Trips

Friday morning I am off with one of my young sons for a church group camping trip, we're going to a remote lake with zero amenities in the mountains that can only be reached by foot. The group has been there several times before, and it is our second time along. Seems like there is much to be learned every year. Some observations to follow.

Last year:

We have driven a couple of hours into the wilds of nowheresville, the last several on logging roads with no railings, boulders in the way, steep grades, and drainage trenches formed along and across the lane so deep that we got several 4WD vehicles stuck.

Observation: Tell the first timers to bring a 4WD vehicle - as long as they know how to drive it. Else, get a ride. I brought my 4WD Suburban only because it was all I had, lucky me.... I wasn't warned. I didn't get stuck, either. The guys who didn't bring the right wheels are unexpectedly carpooling and cramped or riding in pickup truck beds eating dust.

There was still snow on the ground - in August - and the trail in to the lake was a bit obscured. The group got separated. Even the main group was lost for a while before we figured out where the lake was, costing us over an hour of daylight. We're carrying everything we need from tents and clothes to 3 days of food and related survival supplies on our backs. Upon arrival it was discovered that three teenagers were not present. It was about 1730. A short search was initiated but soon abandoned due to deteriorating light conditions. They had everything they needed to survive with them. Mind you, the entire group was made up of men and their sons. Hence, being cavalier manly men, we were not overly concerned and decided to just sleep and try again in the morning. Good thing cell phones didn't work up there, else the Moms would have made it up those logging roads in their Hondas, PT Cruisers and minivans... divots, potholes and truck-eating trenches be damned... and the search would foolishly have continued all night.

Observation: Keep the group single file, in assigned order, with hikers in sight of each other at all times when hiking in with invincible men aged 7-70. The boys were found after a short search the next day, unharmed and amused at the event. It worked out. Some of the Moms still don't know this happened.

And then.... this year:

When the organizational emails started floating out a couple weeks ago, I told them they better warn the new guys to bring 4WD rides. That word got out. It was also stated that due to last year's issues, that the group would by golly stay together from the caravan out of town to arrival at the lake.

And then... the two guys who know the area best.....

Left early. Four hours early.

And left totally useless maps for the rest of us to follow. I mean, I've seen crappy maps, but these were Use Less. Written directions that referred to roads not identified on the map, and arrows on the map with notes that did not match the written directions. As a joke it would have been funny, but a joke it was not.

Observation: When taking a group that contains newbies out into the wild and breaking the promise to keep the group together, at least leave ONE experience guide behind. A couple guys sort of appointed themselves as leaders, who had been out there a few times. I didn't know better at this point. We caravan'ed out there. Dodged boulders, etc. Then, inexplicably, turned around and backtracked over 30 minutes (one more hour of daylight gone), and finally went up another tricky logging road. Just as we entered this new road, the caravan stopped while the first driver removed an intact and mostly clean rib cage, spine and skull... from a deer, I suppose... out of the middle of the road. Cool. As we drove past, I intoned to the guys in my ride dooooom! Gooo baaaaack! Doooooooooooom!

Little did I know.

We arrived at the end of this road and it was nothing like where we stopped last year. Ummmm, where are we? The field commission leader-Dads have huddled with GPS gadgets and maps, looking like all business. They have a topographical map, and have decided they know a better way to get there than last year's 1.5 mile hike over hilly terrain. I look at the map and see a bunch of lines really close together between where they think we are and where we are going. You and I know what this means. But I'm still a new guy, and keep my mouth shut.

Observation: When something looks seriously stupid, say something and head off the stupidity. They led us immediately up this seriously steep incline. I am totally not exaggerating, we're talking about well over 150 yards of 35° to 40° incline, cutting trail in forested terrain with branches and debris and loose soil, with heavy packs on our backs. I was using my hands to climb by just reaching in out in front to grab roots and stuff, it was that steep. The oldest guy in our group abandoned his pack pretty early. I was dying, and we had little kids with their heavy packs crying, slipping, falling down trying climb over fallen trees....

Then we got to the top. A 10' cliff straight up. We were so busy watching our footing that no one looked ahead. Now what? Who is in charge and led us here? My kid is stoic and keeping the struggle to himself, even though he is normally the emotional type. I was pissed.

By the grace of God we were able to traverse laterally a ways and find a crag where a couple of nimble guys scrambled up and then helped the rest of the group make the peak.

We then proceeded to break trail through heavy undergrowth for the next hour or so and then came out:

At last year's parking lot.

With the trucks of those two guys who left early parked in it.

I haven't been that angry in quite a while. I don't really have words for it to put in here.

The hike in from there was uneventful, but a darn sight easier than I remember from last year, having been tempered by the Hillclimb from Hell. The drivers hiked out the next day, unencumbered by the packs, and moved the vehicles to the proper location, via very indirect and winding gravelly mountain roads. So much for four hours of the time we had planned to spend with our boys on the lake. Except... my kid (bless his heart) made the hike with us to retrieve the abandoned pack and get the trucks. He was in front nearly the whole time, for miles, and never lagged. Did I mention that he had already been up since 5AM, when he went fishing and left me sacked out? What a trooper.

Observation: If you don't know what you're doing, just say so and try to keep from screwing things up worse. I can get there on my own now. I will be asserting myself as an organizational leader next year to head some of this comedy off. If those moves are met with resistance, I'll just stay home and take the whole family some other weekend, and let those guys go off to their folly again. Never underestimate the power of a large group of clueless invincible men who think they can read a compass, think they know how to survive in the wild, and become all-knowing guide-gods just because they possess the unharnessed power of a $300 GPS widget.

I know a couple of power dispatchers and quite a few firefighters who suffer from related maladies. They need help, too.

I am not a survivalist nor super-avid outdoorsman. The difference is... I know my limits.

Still, I guess we had a good time:


Arriving at the lake:

My son fishing on the lake Saturday night: Cooking his catch right on the fire, to heck with the cookware:

Tuesday, August 18, 2009

Fireman's Rant Addendum

I've had some more thoughts cross my mind.

This is a follow-up to the original Fireman's Rant on Drivers. If you haven't read that yet, do so and then come back.

QUIT WITH THE CUTE FAKE ROAD SIGNS. Yeah, you've seen them. On someone's garage or at the end of their driveway. Cute, you named your driveway after your clan, and now we all get to know that your little bit of pavement is "Johnson Drive". But let's reconsider, especially in light suburban or rural areas.

Yes, one day you are pulling out of your driveway, and someone who failed to HANG UP AND DRIVE whacks you into the ditch. You are bleeding and unconscious, and the other guy's car is on top of yours and starting to burn. A passing motorist stumbles into the scene, pulls out the handy cell phone and calls 911. County 911, what are you reporting? "Hey, there's been this big wreck, a guy is trapped and there's a fire!" Where are you? (looks around....) "At the intersection of Johnson Drive and County Road 1234."

(Admit it. You KNOW there are plenty of people out there dumb enough to not know the difference between a 'real' sign and the cute one.)

Here one of two things happens:

(1) Sir, there is no 'Johnson Drive' in the County. Can you get a street address on County Road 1234? Oh, by the way, are your mailbox numbers large and legible, on the front and both sides? No? Sucks to be you. Passerby walks up the road looking for someone else's number while you get crispy and/or bleed out.

(2) We'll send help right away. Oh yeah, seven miles up the way there actually IS a real "Johnson Drive" that intersects County Road 1234. Fire and rescue, probably from more distant fire stations, responds to the wrong location, while you get crispy and/or bleed out.

Keep the cute fake road signs out of sight from the road. Thanks.

HEY BRAKE TAPPER, WANNA GET DEAD? I was already going to add this little bit when a delightfully ironic story appeared in the Ventura County Star. So you don't like being tailgated, eh? Sorry, no defense to the bonehead following you, but your smart options are (a) live with it, and (b) let them pass you. And yes, of course, there is a stupid option (c) tap your brakes to 'send them a message'. Yeah, brilliant, the message reads: I am a freaking idiot and am willing to die, maim or kill others, or at least screw up all traffic in order to prove my point.

If all goes well, your brake tap dance slows traffic down for everyone as the braking slinky works its way back up the lane. Are you so important that tailgaters will not be tolerated to the tune of causing traffic delays, unnecessary lane changes, and the increased risk of accidents brought by lane changes and speed differentials?

And what if the bonehead tailgater is doing their lipstick, changing the radio, or texting? Instead of making room behind you, you have just caused an accident that you may or may not survive. Someone farther back may freak out and swerve over the median, wiping out a minivan of innocent children and their Mom. At the very least you've got a damaged vehicle, raised insurance rates, you're late for whatever it was you were going to, and you have caused my brethren, medics and law enforcement friends to all drop what they were doing and come clean up your preventable mess.

Was it worth it?

Ask this brake tapper.

Oh wait, never mind, he's dead. Must have been pretty damn important. Enough so, in fact, that fire crews already on their way to another ostensibly legitimate emergency stumbled into this and had to stop and assist. Not only did he get dead, he also screwed up traffic for miles, scratched his bike up really bad (bummer, dude), risked others' lives, etc... and he prevented help from getting to another emergency. What a hero.

Darwin Awards were invented for guys like this. Are you a candidate, too? Just get out of the way and live another day.

UPDATE 8/30/09: A 2nd addendum has been added HERE.



Monday, August 17, 2009

Tutorial 2 - AC Supply and Demand

Welcome back to another boring ramble. You seem to enjoy this punishment a little too much.

When we last left off, I mentioned how you cannot store AC power. There is no such thing as a battery for AC power, since the basis of the chemical process used to push DC electrons from your handheld gadget and automotive batteries in one direction only is wholly incapable of producing the precise 60Hz, constantly-reversing flow cycle utilized by the North American AC power grid.

Therefore, the power used by AC systems is generated at the same moment that it is consumed.

If you tried to hook up a single power plant to a city with no external connections today, it would be very difficult to control the system's stability and very hard on the power plant trying to do it. When AC systems first came into being a century or so ago, a precise frequency of 60Hz on the nose was not as important to maintain as it is today. For sure, a higher or lower frequency might result in a typical turbine (spinning at 3600 RPM) having funny vibrations and tripping to prevent damage, but relatively wide frequency swings could be tolerated because there really wasn't any sensitive electrical equipment in use by consumers 100 years ago that would burn up if exposed to, say, 59.43Hz or 60.78Hz. By comparison, at today's standards, anything outside of 59.90-60.10 is extremely unusual and would get our attention in a big hurry. 59.95 or lower, in fact, is usually a good indication of a noteworthy system disturbance.

As an amusing aside: Analog clocks on the North American grid, on 120 volt AC plug-in power supplies, are engineered to count one second for every 60 cycles of AC. If the frequency were to theoretically, say, drop to 59.00Hz for one hour, the clock would only advance 59 minutes during that hour. So, even minor fluctuations in frequency, over time, can throw these old clocks off. Accumulated frequency deviations are recorded as Time Error, and the operators of power companies are from time to time ordered to control to a slightly different frequency (59.98Hz or 60.02Hz as needed) in order to keep this accumulated deviation minimized. Heaven forbid an old clock lose two hundredths of a second over the course of a few days.

And yeah, if you plug in a clock built for the European-style 50Hz system into the North American grid, it will spin fast to the tune of 72 minutes for every hour of actual time.

Back to topic.

If you have a perfect match of mechanical-force-moving-a-generator to instantaneous-electrical-demand, the frequency will be 60Hz and all is well. As soon as something gets turned on or off (light switch, blender, table saw, whatever), the balance is disturbed and frequency will change. If there is too much mechanical input compared to demand, the frequency will rise until the balance is restored. This is accomplished by, among many other options, perhaps backing off the water fed to a hydro turbine, or by slightly manipulating the valves at a thermal (coal/gas/oil) power station to reduce the amount of steam reaching the turbine. Likewise, adding demand will reduce frequency until more supply is provided. Once balance is restored, frequency returns to 60Hz. If you get roughly an equal amount of low and high imbalances, the accumulated deviation tends to cancel itself out most of the time.

Now, as I said at the beginning of this post, if you had one power station managing an isolated city, it would be very hard for this power plant to keep up. Imagine at 10:20PM when a huge number of people turn off the 10:00 news and the lights, and hit the sack. The plant would probably not be able to back down fast enough to match the fast-dropping demand. Conversely, at 6:25AM when furnaces, coffee pots, water heaters, and lights all get rapidly turned on, it would be very very difficult for one power plant to keep up and prevent a huge frequency decay and system collapse. 100 years ago, these huge demand swings did not exist at this scale, so single-plant systems that wouldn't survive today were not so stressed out then.

Back in the 30's and 40's, and going forward, power companies began to tie their systems together to increase stability and reliability. By having a power line between you and a neighbor, you could schedule one of your power plants for an outage to repair or upgrade something, without having to black out some or all of your system, because you could fill in the shortfall by buying power from your neighbor, and vice-versa. In addition, if you have huge demand swings on the intertied systems, there are more total power plants exposed to the swings and able to respond. As the number of customers in a single intertied system increases, the individual impacts of things being turned on and off, combined with the averaging effect of having such a huge number of users on the same system, decreases the impact of individual demand changes in proportion to the whole, making load fluctuations much smoother. This in turn reduces wear and tear on power plants trying to chase demand and maintain 60Hz.

An analogy of the above. If you have shopping basket and keep randomly adding or removing oranges, the weight will change noticeably every time something goes in or out. Your arm will get tired of the changes. If you instead have a dump truck and have twenty people randomly adding or removing oranges, even if you do it kind of quickly, the dump truck really doesn't notice. Isolated AC power systems are shopping baskets. AC grid interconnections are fleets of river barges (bigger than dump trucks!) with crowds and crowds of people rapidly adding and removing oranges, and despite the chaos there is never enough sudden coordinated increase or decrease in volume to do much more than make even a slight ripple in the water.

That is probably the lamest analogy I have come up with for a while, but it will have to do.

Since frequency is sychronized on AC equipment tied together, the frequency is for all practical purposes exactly the same on any given point in an interconnection. There are two major interconnections in North America (east and west). Thus the frequency in Maine is exactly the same as that in Louisiana, and the frequency in British Columbia is the same as that in New Mexico... barring system disturbances and 'islanding', of course. If something seriously goes kaboom in Florida and whacks the frequency, dispatchers in Saskatchewan see it within four seconds on their frequency charts, and very likely look at each other and say 'I wonder who just got whacked, eh?'

I can't go on. Half of you are asleep already anyway.

What we learned: (1) AC power is generated almost precisely at the moment it is consumed by controlling output based on demand and frequency. (2) Large AC interconnections made up of bunches of power companies - their generators and loads all tied together - tends to blunt the impact of load changes, which minimizes imbalances in load and demand. (3) There are two huge interconnections in North America. The East is gargantuan, while the West is merely huge (Texas and Quebec are their own AC grids, weakly tied to the big boys with special high voltage DC power lines - more on that some other time). (4) Power companies actually spend time trying to make sure your analog clocks stay precise even though you can usually get the exact time from your cell phone or the Internet in less time than it takes to check or set your AC wall clock, and this of course assumes that you have ever attempted to set your AC wall clock to the precise exact second in the first place.

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Sunday, August 9, 2009

Rewards and Insults

A while back I got singled out in the company-wide newsletter, sent to thousands of employees across many states. I was the lead article in an issue that only had two articles. Thankfully, it was for a good reason.

Here's how it went.

At work at the power company:

There was a wildland fire that was threatening a major transmission power line, which had to be shut down to protect the safety of the fire crews entering the area. It was likely to trip when the smoke and debris got into it anyway. Being a combination power guy and fire guy in my two lives makes me very sympathetic to the needs of the fire crews under and around my wires.

This time, however, there was a major industrial user on the line which must perform evacuation procedures when they lose power. So, I first called the big customer's control facility and warned them, and then dumped the line. I called them back fairly often to keep them appraised of the situation as it progressed, and kept in touch with the fire dispatchers as well.

Some sort of manager person at the big customer apparently liked my way of handling this incident enough that he wrote a nice note to my boss. Cool.

That night at work at the fire department:

Had a nondescript garage fire. I arrived in the 4th-due piece, which was never used on the call, just parked out of the way. I was late enough that I missed the initial attack entirely. I ended up shadowing one of our new guys as he played Water Supply Officer for the first time, answering his questions and prompting him as needed. He did fine. I really didn't do jack.

One of my coworkers just happened to live next door to this call, and found out I was there. The next day, she wrote a nice note to my boss. Cool.

My boss forwarded both of them to his boss. Ummm. It spiraled out of control from there, and an executive summary of a day in the life of the Grumpy Dispatcher ended up in the company newsletter a few days later.

You know, I really didn't mind, but let's be real here. Doing notifications and dumping power lines is just a small part of my job. It is not extraordinary or difficult. Driving a tanker to a fire and mentoring a new guy while not getting dirty is easy as well. I have had far, far scarier days at the power company keeping people from getting killed, and for sure have had far hairer fire and rescue calls. The only thing this time is that two unrelated nothing events somehow resulted in nice emails to my boss referring to the same day. That makes me a hero? Yeah, the only person laughing louder than you is me.

But the newsletter poke was OK.

I was reminded, however, of two times where the poke was delivered differently. I have to live up to my Grumpy nature and complain.

First case: One of my old Senior Dispatchers had a truly hairy incident where a couple of line guys narrowly escaped death only by his razor-sharp situational awareness and fast reaction. I wonder if I ever have a chance to be half as good as Rich. Anyway, the next day, the boss called him into the office. Rich is standing in front of the desk, kind of disinterested, the boss doesn't even stand up. Boss says some nice words about how Rich saved the day, reaches into a desk drawer and pulls out a fanny pack with the company logo silkscreened on and says something along the lines of how he just wanted to give him something to say thank you. You gotta know Rich, and apologies to any who may be offended, I am only the reporter here.... Rich takes the fanny pack, turns it over a couple of times, tosses it back on the desk and walks out saying "Why don't you just keep your fag bag, I've got to get back to work."

We don't need nor want a reward for what we do. We know what our job is and the consequences of failure. We are not motivated by trinkets or trade show handouts.

Second case: I was frustrated by the lack of usefulness of some of our software displays and was getting nowhere with requests to improve them. So, while on shift and still fulfilling my regular duties, I taught myself how to use the software to make my own displays. I learned where things could be found in the huge database, built some really excellent interfaces, refined their look and feel, etc. Now everyone uses my displays on all the shifts, and I have to maintain them when there are changes - while still doing my regular job - because no one else really knows how they are built or maintained. It's cool, actually, I kind of enjoy playing with this stuff.

The reward from management when it became clear what I had pulled off after hundreds of hours of work on this stuff: A $25 gift certificate to Target.

You know, just keep it. I'm just doing my job, and let's be honest... I am getting paid well enough that a gift certificate is just a fart in the wind, anyway.

However, when I rescue a falling baby while on crutches in the snow or otherwise save the world, I'll probably go ahead and take your gift certificate and buy myself a new DVD or two for the collection, because I do like movies.

Monday, August 3, 2009

Tutorial 1 - DC vs. AC

I got only one reply on the post asking if a tutorial series would be helpful. The one response was in the affirmative. So I guess it is unanimous, 100% of the responses were in favor of the tutorial stuff. Thanks for the vote.

I see the rest of you, you're generating bits of data on the traffic report. Little bits. But we're new here... and as I recall writing not too long ago, this blog is about me and my therapy, anyway, and not about what you want. So I'll continue the therapy and you can decide if you want to try to keep watching or not. I won't blame you if you turn away, unable to continue to observe the train wreck here.

Here's where I'll start the tutorial series. But I promise to try to amuse you with other topics as we go along.... don't plan on a straight uninterrupted series of boring tutorials.

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Power grid interconnections are operated as alternating current (AC) systems. Most folks out there are familiar with direct current (DC) systems, with the traditional red positive and black negative lead wires, such as found on anything that uses a battery.

I'll push a moment on DC and batteries, because people are more familiar with them. I'll then use that foundation to explain how AC is different.

People often think positive equals ( + ) and that power comes out of the battery on its 'top', and that negative equals ( - ) and that the return path goes into the battery on its 'bottom'. Truth be told, the symbols refer to the flow of electrons relative to the battery itself. They come out (are 'subtracted', if you will) from the negative terminal, go out through the black wire, go do their thing running the whatever, and then return via the red wire to the battery (are 'added') through the positive terminal.

I suspect that I just turned the battery-using world of perhaps 85% of my readers upside down. Yes, some of you are applying what you just learned to automotive electronics if you've ever had to deal with that. And yes, the entire frame of the car is energized via the "positive" flow sourced from the negative terminal which subtracts flow from the battery, looking for a path back to the battery via wires to the positive terminal. That huge cable running from the starter to the battery? Yeah, that's the return path. Really. The so-called grounding strap off the negative terminal should be equally large, as it has to support the battery's outflow to start the car.

OK, so you all have the concept of single-directional flow down, right? Direct current. One way. From here to there.

Now, alternating current is a different game entirely. In an AC system, the current flows out and reverses direction along the same wire, rapidly. The neutral (ground) wire provides a balancing or pass-through point, if you will, so the electrons don't pile up and get "squished" at the remote end. It's actually quite a bit more complicated and technical than that, but we don't need to get into it for purposes of this blog. Suffice to say, AC systems do not have a 'positive' and 'negative' wire, rather they have a 'hot' wire (black) and a 'neutral' wire (white). On power poles, the hot wire(s) are at the top of the pole, and the neutral wires are lower down, at the base of the transformer cans mounted to the pole. Stuff below that is cable TV, phone, etc. The power comes and goes via the hot wire, whereas the neutral wire is tied to an electrical ground, literally (if installed correctly) via a 6' metal rod driven into the dirt or some other equivalent grounding installation at your home, and via a metal grid "grounding mat" under the gravel at electrical facilities such as substations.

Two important notes about AC:

1 - There is as yet no efficient way to store energy that can serve as a source for an AC system. Batteries use a chemical-based process to push electrons out of the battery in one direction. There is no chemical process that can push and pull electrons back and forth in the format of AC current. Therefore, all energy generated to serve the AC power system is generated at the same moment that it is consumed.

2 - The rate of the AC power current send-and-receive cycles, in North America, is 60 times per second, referred to as 60Hz or a 60 cycle system. That means every second, electrons arrive to do their thing, and are then returned, 60 times per second, and this super-fast back and forth action is what produces the quiet hum you hear from various electrical components, and the loud hum from electrical substations. I referred to the 60Hz rate in Compliance Follies. The hum you hear from a substation would rise or fall in pitch if the rate ever changed much, but in reality the rate will never change enough for anyone to audibly detect a difference (unless it goes to 0Hz, in which case it gets very quiet and our slow workday becomes busy). Much of Europe runs at 50Hz, which is why some sensitive electronics will not work in both places. In early electric systems, 25Hz was common, and this rate was slow enough that the unaided human eye could easily detect the flicker in light bulbs as they received power 25 times per second.

What we learned: (1) Batteries flow the other way, and Mom never told us that. We are traumatized by the revelation. (2) You cannot store AC power. (3) AC is weird.

More later.

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Saturday, August 1, 2009

Learn the Grid. Attract the Ladies.

This blog is sooooo new, yet people are already reading it... I can see the stats and am surprised. As MotorCop so eloquently stated, and I am merely paraphrasing here, this freaks me right the frack out. But I also have to acknowledge to myself... hey dummy, you put it on the Internet, what exactly were you expecting?

I only put up one power company post so far, and although I tried to keep it very elementary, the comments tell me that it was still jargonized greek. Thus not very entertaining. Like any line of work, you get immersed so far into it that sometimes it is hard to explain to someone with little or no exposure. Sorry about that.

I will start a series of posts to explain the power grid and power dispatching from a very basic level, and with any luck get all three of you regular readers qualified to pass the NERC certification exam and be dispatchers as soon as possible. Honestly, we could use the help, and it pays pretty well.

Seriously, is anyone interested enough in how the grid is operated to make it worthwhile for me to make a dryly cynical tutorial series? By the end, you'll know enough to impress the chicks at parties with your extensive power grid knowledge, especially when they want to talk about the blackout that just happened (and there will be one eventually, just wait). Unless of course, one of us power dispatchers is also there and chooses to out you as an imposter. And even then, it only works on the chicks who dig grumpy blue collar types who think like self-righteous engineers.

On the other hand, if you're female, I am not sure how the men will react to your grid knowledge. Unless it's a power dispatcher. We love to talk shop!

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