Delhi discoms using advanced-technology transformers to ensure uninterrupted power supply

The power distribution companies (discoms) in Delhi are leveraging advanced technology transformers to ensure a continuous supply of electricity, with peak demand nearing 8,000 MW amidst a severe heatwave.

BSES spokespersons highlighted that their transformers are designed to operate at temperatures 40 degrees Celsius above the ambient temperature. “This means if the area temperature is 48 degrees Celsius, these transformers can function up to 88 degrees Celsius without additional cooling,” they explained.

The BSES discoms, comprising BSES Rajdhani Power Limited (BRPL) and BSES Yamuna Power Limited (BYPL), cover most of Delhi except the northern regions.

“Thanks to modern design and technology, these transformers do not require external cooling aids like fans,” the spokesperson added.

Overheating and burning of transformers due to extreme temperatures can lead to prolonged power outages. In extreme cases, if temperatures exceed 88 degrees Celsius, external cooling fans are deployed to reduce the temperature to safe levels, the BSES representative noted.

In North Delhi, Tata Power Delhi Distribution Limited (TPDDL) manages 88 grid substations at the 66-KV and 33-KV levels with 222 transformers. These are monitored and controlled remotely via a central Supervisory Control and Data Acquisition (SCADA) system, according to a TPDDL spokesperson.

“With soaring temperatures this summer, maintaining optimal performance of our power transformers is crucial for effective functioning,” she emphasized.

On Wednesday, Delhi recorded its highest-ever peak power demand of 8,302 MW, alongside a maximum temperature of 46.8 degrees Celsius, the highest in 79 years. The following day, the peak demand was 8,091 MW at 3:28 PM, with a maximum temperature of 45.6 degrees Celsius. The weather department has forecast a maximum temperature of 44 degrees Celsius for Friday.

TPDDL transformers are specially designed for Delhi’s varied seasons and environmental conditions. They utilize an “Oil Natural Air Natural” (ONAN) and “Oil Natural Air Forced” (ONAF) cooling system to maintain temperatures within permissible limits during the summer, the spokesperson mentioned.

An automatic cooling system activates cooling fans or oil pumps based on the oil and winding temperatures of the transformers. Remote monitoring via the SCADA system allows for close supervision of these temperature indicators, she added.

Furthermore, TPDDL employs industrial blowers, strategic load shifting, and sharing between transformers to prevent overheating. Online monitoring, including thermos-scanning and ultrasonic testing, ensures that the transformers remain in peak condition even under the most demanding conditions, the TPDDL spokesperson concluded.

(With PTI inputs)