Stability And Voltage Studies

The NYISO Operating Committee on Friday approved three studies aimed at helping the ISO alleviate congestion on its grid.

The ISO’s Central East and Total East interfaces study reports, and its Central East voltage limit study, each sought to identify areas of the grid in need of upgrades to ensure it operates reliably under several different demand and environmental conditions.

The first two reports updated the definitions of the transmission components that make up the Central East and Total East interfaces and examined the impact of adding new 345-kV lines to the interface.

The Central East voltage limit study evaluated the grid’s performance after the addition of several new lines and found that performance improved, allowing for an increase in the minimum level of energy loss that triggers contingency operations.

NYISO expects the new interface criteria to be integrated into grid operations following the deployment of updated models and software in October.

Shortage Pricing

The OC also approved manual revisions NYISO says would improve the accuracy of transmission shortage pricing by better reflecting the actual costs of relieving constraints.

The changes involve eliminating transmission constraint “relaxation” logic for facilities and interfaces that use a demand curve mechanism and introducing a six-step mechanism for those assigned a non-zero constraint reliability margin.

NYISO argued the revisions would reduce market inefficiencies by more accurately pricing the relief services that certain transmission projects provide to the grid.

The Business Issues Committee had approved the revisions the previous day. They are expected to become effective in October after the deployment of software updates.

August Operations Report

Aaron Markham, NYISO vice president of operations, informed the OC that August saw a peak load of 24,917 MW but that the summer’s peak load of 30,200 MW occurred due to a heat wave Sept. 17.

Markham noted that the heat wave resulted in appropriately 1,500 MW of unforced outages.

He said NYISO is investigating the cause of the outages but that it had sufficient resources.

Markham also said the ISO has added 3 MW of energy storage and 66 MW of behind-the-meter solar resources since last month.