TSS 76 300MVA Transformer Replacement in Blue Island

As part of Commonwealth Edison’s GRIP Program, Milhouse Engineering & Construction, Inc, is providing protection & control engineering design services at TSS 76 Blue Island Substation.

ComEd will be replacing the 300MVA TR 82 and installing a 345kV circuit breaker and bus side motor operated disconnect on the high side of the transformer. The current MOD on the high side of the transformer and 34kV tertiary capacitor bank will be removed. The 138kV conductor from TR 82 will be upgraded. Two new 138kV 57.6 MVA capacitor banks will be installed. A new 138kV capacitor bank circuit breaker and MOD will be installed. Two new 138kV capacitor bank circuit switchers with pre-insertion inductors will also be installed.

Milhouse is responsible for the design of:

• The protection and controls for all new equipment
• The breaker failure design for all new breakers
• New current transformer contributions to the 345kV L.11614 from the new TR 82 circuit breaker
• Modified tripping and closing controls for L.11614 to include the new TR 82 circuit breaker
• New fiber communication to the new equipment to be used for monitoring
• New bus protection for 138kV Bus 2
• A new communication processor, SEL-2032, to allow for communication between the new protective relays, transformer, and breakers
• A battery study to determine the impact of the DC load from the new equipment