How we helped
SynchroGrid performed a wide area screening analysis of protective relays utilizing in-house automation algorithms to perform the relay coordination, cross-check results, identify weaknesses in the protection system, and automate the NERC PRC-027-1 R2 reports.
This project required a massive study to evaluate relay protection coordination for all transmission protection at 138kV and 69kV systems. This study was performed to comply with Requirement 2 of NERC-027-1, as well as to uncover areas of high risk, mis-coordinated relays, relays tripping out of order, out of zone, incorrect relay settings, etc. In this project, SynchroGrid performed a Wide Area Scanning Analysis of all applicable transmission protective relays to evaluate proper selectivity and sensitivity. SynchroGrid performed this study across 31 substations, 53 138kV terminals, and 36 69kV terminals. Relay settings were evaluated according to PRC-027-1 requirements as follows:
- 21 Distance elements, including infeed and mutual coupling effects
- 50 Phase and Ground Instantaneous Elements
- 51 Phase and Ground Time Elements
- 67 Phase and Ground Directional Elements (non-pilot)
In the course of executing this study, SynchroGrid:
- Verified the transmission system short circuit model, topology, impedances, relay settings, line ratings, naming, and other characteristics
- Evaluated various operating conditions such as winter cases and presence of local generation
- Evaluated relay settings against our client’s established philosophy
- Established coordination and violation criteria
- Evaluated protective elements under N-1 contingencies
- Delivered a report documenting results and recommendations
