Analyzing the impacts of out-of-market corrections

Abstract

The electric power grid is one of the most complex engineered systems today. Managing thousands of transmission assets spanning many miles and interconnecting regions and countries together combined with optimizing many generators with complex operating requirements creates a very challenging scheduling problem. Such a challenging problem becomes even more complex with resource uncertainty and stringent reliability standards. In order to solve such complex optimization problems within reasonable timeframes, approximations are required. The consequence of such approximations, however, is the need to implement out-ofmarket corrections (uneconomic adjustments). This paper presents an overview of out-of-market corrections, an overview of industry related practices that require out-ofmarket corrections, multiple algorithms that can be used to determine out-of-market corrections, and the various costs and market implications due to out-of-market corrections.

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

“…With the evolution of the smart grid, more customers may voluntarily curtail themselves at a cost. Operators may also reduce the expected load shedding by repairing unreliable market solutions (these actions also tend to also have a cost [26]). Given the many ways to mitigate load imbalances, the use of ν in this paper is intended as a rough penalty for not satisfying all constraints in the modeled scenarios.…”

Day-ahead corrective transmission topology control

“…For cases that lead to load shedding (violations) with contingency analysis, the operator would need to implement security corrections in order to make the UC solution N-1 reliable [19]. Such costly corrections will be referred to as out-of-market corrections (OMC) [20].…”

Probabilistic Decision Making for the Bulk Power System Optimal Topology Control

“…Practical implementation concerns and impacts on circuit breaker reliability are studied in [37]- [40]; AC formulation of topology control optimization is approached in [41], [42]; Out-of-market corrections of the AC infeasible market solutions for day-ahead accommodation of transmission line switching is investigated in [43], [44]. Scalability concerns of topology control implementations in real-world power systems are addressed in [19], [45]- [49].…”

“…As a result, it is suggested that the AC feasibility be conducted in the next step for each topology control plan obtained earlier through the PEM. If the AC power flow does not converge, different adjustments may be tried (known as out-of-market corrections) to aid the convergence with the available reactive power sources such as further tuning of shunts, generator voltage set points, transformer tap settings, and so on [43], [44]. If AC feasibility is confirmed with all the adjustments satisfying the generator reactive power constraints or if the optimal topology control plans are originally decided using the ACOPF solvers, the system transient stability check is performed using the output of the AC load flow as the initial conditions for the machines.…”