Locational Reserve Disqualification for Distinct Scenarios

Abstract

Abstract-Reserve requirements promote reliability by ensuring resources are available to re-balance the power system following random disturbances. However, reliability is not guaranteed when reserve dispatch is limited by transmission constraints. In this work, we propose a modified form of reserve requirement that identifies response sets for distinct contingency scenarios. The approach disqualifies reserve from counting towards a particular scenario if transmission constraints are likely to render that reserve undeliverable. A decomposition algorithm for securityconstrained unit commitment dynamically updates the response sets to address changing conditions. Testing on the RTS 96 test case demonstrates the approach applied in tandem with existing reserve policies to avoid situations where reserve is not deliverable due to transmission constraints. Operational implications of the proposed method are discussed.

Capacity response sets for security-constrained unit commitment with wind uncertainty

“…The response sets in (18) are similar to existing capacity constraints in CAISO and ISO-NE. The major difference is that they can change to meet the needs of individual scenarios.…”

“…The flowchart in Figure 2 base commitments do not work well for some scenarios, the response sets are pruned (C and U are made smaller) to remove capacity that was less helpful than expected. The revised response sets are reapplied through constraint (18) in the next iteration to encourage SCUC to commit more preferable slow generators moving forward.…”

“…• undeliverable due to transmission constraints. This paper addresses the above issues by adapting the idea of response sets from [18]. If operators require capacity commitments before the scenario is known, the response set is defined as all capacity that may count toward that requirement.…”

An Enhanced Security-Constrained Unit Commitment Model with Reserve Response Set Policies

“…Today, most of the ISOs use reserve zones to ensure that sufficient reserve is held within import-constrained areas. A simplistic representation of one such reserve model [21], which is an extension of the reserve model used by ISO New England [6], is given below:…”

“…The hourly ramp rate constraints are shown in (18) and (19). System-wide spinning reserve requirements are modeled in (20) and (21). Constraints (20) and (21) together require that the system-wide reserve be no less than the single largest generator contingency or % of the total demand in the system, whichever is greater.…”