When the network turns off

If you survived the 2000 problem, Y2K, then you may remember this hype with almost no consequences. With the transition of the calendar from 1999 to 2000, many predicted the opening of catastrophic errors in the software of the machines that controlled our banks and infrastructures. The potential catastrophe did not meet the expectations, but at the beginning of the new millennium another serious infrastructural catastrophe occurred, which led to massive power outages (blackouts) in North America. On the scale of the tragedy, it might have seemed that the delayed consequences of Y2K had worked, but the real reason for the outages was simply the organizational problems of the network itself.

Built-in protective equipment

Although disconnections of the scale of those that occurred in the early 2000s are quite rare, small local disconnections almost always occur sooner or later. Although power plants are motivated to maximize protection from these incidents (no energy — counters are not spinning), there is no guaranteed way to protect against lightning striking power lines or expensive equipment, or against illegible electricians overloading panels and damaging transformers or birds nesting nests in substations.

In theory, in the event of any problem (electrical system failure), there are a great many protective devices designed to minimize downtime. Most of the problems are short-term failures, self-eliminating rather quickly. Lightning can strike the line or a branch can fall on it. Instead of turning off the safety switch, which then needs to be turned on manually, small devices for automatic restarting (AR) can re-energize sections of the network that have experienced a temporary failure (intermittent damage). In case of sustained damage, a larger switch will work, but you will have to turn it on manually after the damage has been repaired by electricians. One-time fuses are often found in the electrical network, which, unlike automatic reclosing devices and circuit breakers, have to be replaced later.
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Toronto during a massive power outage

Perfect failure

But all of this protective equipment has its drawbacks, and under certain conditions it can start to behave badly, which can lead to unusual consequences. This is what happened during the 2003 northeast outage , when the transmission line in Ohio touched a tree. Usually such a case would be quickly resolved with the help of security equipment and network operators. But it was a summer day, and the contact was due to the fact that the line sagged more than usual, passing the current close to the maximum possible. More current - more thermal expansion of the wires, and more likely to come into contact with what is not needed.

Since this was a summer day, after disconnecting the first transmission line, the entire normal load plus the entire peak load should have been distributed over other circuits to avoid energy shortages. And usually it would be easy to implement, but the other circuits were also under peak load, and after they suddenly received additional energy, they turned off, causing more lines to become overloaded, and even more circuits to turn off. As a result, more than 50 million people in the United States and Canada were left without electricity. At that time, it was the second most common power outage [the largest disconnection in history occurred in India in 2012 and affected 620 million people. - approx. perev.], and led him to such simple circumstances as a hot day and a small error in the computer, which allowed the cascade trips quickly get out of control.


Times Square during a trip in 2003

It should be noted that power companies are commercial organizations, therefore the construction of a power grid that is more durable than necessary does not have a commercial meaning. Of course, it always makes sense to have additional safety capacity, and the Ohio company at some point could really act dismissively, but at least they were not completely negligent. In addition, the hind mind is always easy to find the guilty.

Outages as a business model

On the other hand, there were also such outages, which were specially organized by companies seeking to profit from this. The California Energy Crisis of 2000–2001 is a practical example of a conflict of interest when an energy seller like Enron , which controls energy supply to the state, also sells energy futures. This practice has already been banned, but this required that this company, known today for corruption, dubious business practices and bankruptcy, catalyze changes in the laws that allowed such a lack of regulation in the energy market. California during this crisis was constantly subjected to cascading outages, despite the fact that the transmission system was reliable enough to withstand all requests, and the generating capacity was sufficient to meet the needs of the entire state without any outages.


New York during the 1977 outage

We start the power station "by smoking"

Despite Enron’s increased authority in North America, which is able to cope with such problems, power companies are required to restore power after a shutdown. Although the damage to the network needs to be repaired, supplying energy to it from a nuclear power plant or from a gas turbine is not as easy as clicking a switch. If the power plant ceases to produce energy, it needs either external power supply or a so-called start-up. the black start system (generators), which start larger diesel generators, giving the necessary energy. It is necessary to start steam boilers, move control rods, supply fuel — and all this requires energy. Usually, companies use hydropower stations for the “black start”, but in those places where it is impossible to dam the river, other technologies are used.

Small power cuts can occur anywhere, and large ones occur relatively rarely, despite the aging infrastructure and negligent companies. Of course, on the scale of a whole network, the transfer of energy can follow a very complex pattern. In the next articles in the series, we will look at smart grids: modernizing the power grid and how modern technology helps to improve it.