Utilities Face Challenges of Maintaining Transformers

“As prices of transformers have shot up 3.5 times compared to last year, replacing the old and aging devices will cost at least $900 million,” ILNA reported Arash Aqaeifar as saying.

The IEIS member noted that the Energy Ministry cannot afford the new transformers as it already owes $2.5 billion to private power producers and other contractors.

According to Aqaeifar, buying new transformers is not a priority, so instead of replacing the old gadgets, provincial electricity distribution companies should come up with effective options such as modern maintenance procedures, status monitoring and timely repairs. 

Maintenance plans have not worked as expected and machinery and equipment are usually used up to breaking point and then repairs are undertaken, he rued.

“This policy must be rewritten and instead condition-based maintenance should be the norm.”

Condition-based maintenance is a policy that monitors the actual condition of an asset to decide what maintenance needs to be done. CBM dictates that maintenance should only be performed when certain indicators show signs of decreasing performance or upcoming failure.

Such measures reduce costs in the long run and help reduce power loss in the distribution network, he said.

Referring to locally-made distribution transformers, he said: “Foreign engineers and power experts who visit factories in Iran say the country has the ability to manufacture a variety of devices in compliance with global standards. Where we need improvement is in the repair sector.”

It is regrettable that much of the repair work on transmission equipment is carried out in non-standard workshops that do not uphold standards and do not carry out stringent tests to ensure the quality of the repairs. This has led to high level of accidents, he recalled.

The average life of renovated transformers is unacceptably low, he said, and noted that a repaired transformer that has passed appropriate tests should not be dissimilar from a new one.

Close to 7,000 transformers with the capacity of 400,000 megavolt ampere are used in the national power grid.

A distribution transformer provides the final voltage transformation in the electric power distribution system. It converts the voltage used in the transmission lines to one suitable for household and commercial use, typically down to 220 volts. 

“To meet growing electricity demand an estimated 9,000 megavolt amperes in new transformer capacity should be added to the network every year.”

In related news, ILNA quoted Mostafa Rajabi Mashhadi, a spokesperson for the state-affiliated Power Generation, Distribution and Transmission Company (Tavanir), as saying that capacity of power substations, including transmission and distribution, has increased by 10,000 megavolt ampere since 2019. The capacity of substations currently is 121,000 megavolt amperes.

Mashhadi said the number of transformers has reached 7,000 including distribution, step-up, step-down, medium and large gas-insulated equipment.

Tavanir’s maximum generation capacity is 60 GW and network load approached 58 GW in summer.