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A Shutdown of the Rules
// Kommersant investigates the causes of the power crisis
Electroshock
The Moscow Prosecutor's Office gave a report yesterday on the first results of the investigation of the power blackout that occurred on May 24 and left several million people without electricity. The Prosecutor's Office has not established the guilty party in the power crisis – to do this, the investigators will have to determine the cause of the accident at the Chagino substation and understand why the power engineers allowed it to spread through the system in four Russian regions. At Mosenergo, they think the investigators first need to find out who is to blame for the cascading power failures - the supplier or consumers. Sergey Dyupin has the details.
Twenty-seven Seizures and 63 Witnesses
It follows from the report of the Moscow Prosecutor's Office that its personnel, who are investigating a criminal case of negligence and abuse of authority initiated in connection with the power crisis, have already completed the first stage of this work. This concerns the preliminary examination of witnesses, document seizures, and removal of parts of the damaged units from the Chagino substation where the accident occurred.
“Our people have received all the documents necessary for investigating the criminal case,” the Moscow Prosecutor's Office reported. “In order to obtain them, the investigators made 27 seizures at various organizations belonging to RAO UES of Russia.” The investigators also examined 63 witnesses, including the heads of RAO UES and Mosenergo.
In addition, the report noted that “an investigation is being conducted into the financial and economic activities of the power companies responsible for updating and refitting equipment. This work is being carried out in conjunction with an analysis of the technical causes of the accident and a determination of the cause-and-effect relation to the massive power failures that followed.”
In the opinion of Vladislav Nazin, Mosenergo's deputy general manager, who has already been to the prosecutor's office for questioning, the investigation of the circumstances of the power crisis needs to be clearly divided into two lines – some people must bear responsibility for the accident at the Chagino substation, and others, for its consequences. “The substation personnel are obligated to maintain the equipment in working order and promptly eliminate the consequences of accidents that occur there,” Nazin explained to Kommersant, indirectly admitting his department's involvement in the accident. “However, the cascade development wasn't our fault.”
The Equipment Is Obsolete,of Course
Recall that on May 24 at 21:17, a transformer of a 110-kV distribution device at the Chagino substation blew up. Its fragments damaged several instrument transformers, air ducts, and conductor lines, after which the 220-kV line supplying the Moscow Oil Refinery in Kapotnya and nearby neighborhoods was automatically cut off. As a result of the accident, Moscow's Cogeneration Plant 22, which feeds electricity to the refinery through Chagino, had to be partially shut down.
As Chagino employees explained, the ceramic transformers often blew up, but these accidents usually did not affect the substation's operation. The damaged units were automatically excluded from the general circuit, and similar devices began to perform their functions; and personnel fully restored the damaged unit within a day or two.
Experts at the Moscow Prosecutor's Office are now studying the transformer's fragments in order to determine the cause of its destruction. They are not ruling out the possibility that it may have exploded from deterioration. Like the rest of the equipment at Chagino, the transformers long ago used up their resources. However, the power company has been in no hurry to replace the transformers, alleging a lack of money for modernizing them, because power rates are too low. According to another version, it is not a matter of rates, but rather that RAO UES of Russia is nowhere near completion of its restructuring period. It is planning to transfer Chagino from Mosenergo to the federal level; therefore, it simply makes no sense for its present owners to invest money in reconstruction.
It is also not inconceivable that the explosion of the transformer occurred due to a violation of its operating regulations. “The equipment is obsolete, of course, but we got through the winter OK,” Nazin explained to Kommersant. “And during the cold season, the load on the network was incomparably greater.”
If it is established that conditions for the destruction of the transformers were present (the first accident at Chagino occurred on May 23) and substation personnel, knowing of them, did not take measures, its employees are responsible. If the station personnel convince the investigators that they recorded the jump in pressure in the transformers in the log and reported them to their supervisors, then Mosenergo's managers were responsible.
The Crisis Could Have Been Averted
Thirteen minutes after the transformer exploded, the power supply to the oil refinery and four adjoining Moscow neighborhoods fed from the cut-off 220-kV line was switched over to the 110-kV reserve circuit and restored. It was this action, not the accident at the substation that then triggered a system crisis; therefore, the prosecutor's office has to investigate whether an emergency restoration of power was necessary on the evening of May 24. Nazin believes that consumers should have been cut off immediately after the accident in order to extinguish the fire, deal with the damage, think it through by the next morning, and set up a reserve circuit for them. “A couple hundred thousand people would have been without electricity for two hours or so before going to bed,” Nazin explained. “Of course, it would have been inconvenient for them, but we would have avoided a cascading spread of the accident to the entire Central Region.”
Vadim Zinakov, Mosenergo's chief engineer, explained to Kommersant why the electricity was nevertheless quickly turned on. According to Zinakov, Mosenergo started receiving signals of serious problems arising at the oil refinery.
“On the evening of May 24, immediately after the accident, we switched the oil refinery to the reserve 110-kV power line,” Zinakov told Kommersant. “But the refinery's internal network wasn't prepared for this changeover.” Zinakov explained that there were several power supply categories at industrial facilities – high (through four independent circuits), first (three circuits), and second (two circuits). In his words, facilities with a continuous production cycle must be supplied only from the high category, but the Moscow Oil Refinery was getting electricity from only two lines, that is, not even first but second category.
As a result, after the accident, a single 110-kV power line carried the refinery's entire load of 80 MWh. But since the throughput capacity of the 110-kV line was about 100 MWh, and it had to supply four Moscow neighborhoods in addition to the refinery, the line was operating at its limit.
Several hours later, at 5:31 on May 25, a third transformer on the overloaded 110-kV line from Kraskov blew up at Chagino. As a result of the accident, the air pressure in the other transformers dropped. For a while longer, current to the 110-kV line was taken from the Moscow ring through a 500/110-kV transformer; but when it broke down, the entire southern part of the capital was hanging on 220 and 110-kV systems, as power engineers put it. As long as household demand for electricity was low, this capacity was enough for the city; but at 10:12, when the usual morning increase in loading occurred, cascading failures began. First, the overloaded 220-kV lines from the Ochakovo high-voltage substation cut out; then the automatic safeguards cut off the long 220-kV lines coming from Tula and Kaluga. When the 220-kV system fell, a chain reaction began in the 110-kV network. According to specialists, as a result of the emergency cutoffs and switchovers at Chagino, the intricate connected system of stations, substation, and high-voltage lines of Moscow Region's power supply system lost its overall stability. After that, cascading failures became inevitable in the morning, and no one could do anything about it.
Power engineers think that if the oil refinery had had at least three supply lines, the load would have been distributed more equally after the nighttime accident, and the morning cascading failures could have been avoided. “We have informed the refinery's management many times about the need to connect additional lines,” Zinakov said. “But each time they have refused, obviously hoping it will go away.”
Nikolai Frolov, a spokesman for Moscow Oil and Gas Company, confirmed to Kommersant that there were actually problems with the refinery's power supply, but its management was going to solve them by other means than bringing in new lines. “Management is currently discussing the construction of an in-house power station for the refinery,” Frolov explained to Kommersant. “However, this requires major financial outlays; it would cost about $1 million per MW to build a generating facility at the refinery. Only the refinery's principal shareholders can make a decision on that kind of capital investment – the Moscow government, represented by the Moscow Oil and Gas Company, and Sibneft, and Tatneft.”
An Unreliable Circuit
If the Moscow Prosecutor's Office establishes that the power engineers were in too much of a hurry to switch the refinery over to reserve lines on the night of May 24, it has to find out who made this decision. As one of the employees on duty at Chagino that night explained to Kommersant, the personnel on the evening of May 24 “weren't in the mood for consumers”. A fire raged 150 m from the office building. What is more, the decisions to switch over the high-voltage power flows in emergencies were not made at the substation, or even at Mosenergo, but at the federal level. The regional dispatcher of the unified dispatch control under RAO UES of Russia does this, and he is responsible for his decisions. Three days after the crisis, Moscow Mayor Yury Luzhkov spoke of the bad dispatching at RAO UES. However, he did not explain what he meant, so investigators also have to determine what compelled the specialist entrusted with the central power flow control console to choose an unreliable reserve circuit.
“Previously, in case of an accident, the dispatcher had the right to pick up everything, that is, to take electricity from any station, guided solely by considerations of reliability,” an employee of the dispatch control office told Kommersant. “Now he's obliged to choose the cheapest station among those supplying their production to the federal power market. There are auctions going on every day on this market, and a nonmarket reserve fund to compensate for emergency cutoffs no longer exists.”
Nazin is certain that, in an emergency situation, the dispatcher would never be guided by economic considerations, but he might have made a mistake because of damage to the TV equipment on his console. Sergy Pronin, the deputy chief engineer at Mosenergo, maintains that on the night of May 24, no orders came to Chagino from the operator dispatch control office of RAO UES of Russia.
Sergey Dyupin
All the Article in Russian as of June 03, 2005
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