Evgeniy Goldis

Power market reform in the presence of flexible schedulable distributed loads. New bid rules, equilibrium and tractability issues

We investigate the shortcomings of current day-ahead-market designs in eliciting socially optimal demand response and obtaining regulation service reserve offers from flexible loads. More specifically, we show that under the current day-ahead-market rules, individual flexible loads have the perverse incentive to self-schedule based on their estimate of market clearing price trajectories, rather than reveal their true utility. Furthermore, convergence of estimated market clearing prices to the socially optimal equilibrium, although theoretically feasible in a carefully designed iterative approach, is quite impractical for the application at hand. We propose modified market rules that remove the perverse incentives and allow the market to clear and discover the socially optimal equilibrium prices which are stable w.r.t. individual self-dispatch. We prove our claims and verify them with extensive numerical investigation.

AC-Based Topology Control Algorithms (TCA) -- A PJM Historical Data Case Study

Transmission topology control (line switching) is currently practiced with manual and ad-hoc based actions by ISO control room personnel who rely on a combination of past experience and a fixed data set of line openings linked to various congestion patterns. Our previous work used sensitivity information from the solution of a DC economic dispatch problem to develop topology control algorithms that significantly improve the operators ability to select promising lines to open/close. In control rooms, however, algorithms must rely on AC-based power flow tools to ensure feasibility in the physical network. Considering the computational time constraints that must be met in an operational setting, iterating between DC-based topology control algorithms and AC power flow validation of proposed topology control actions may become intractable in large systems. In this paper we present real system size computational results relying directly on AC-based topology control algorithms that we have developed. In particular, we discuss a case study on three historical weeks of PJM system data where AC-based topology control solutions are presented and compared to the corresponding DC-based solutions.

Security-Constrained Transmission Topology Control MILP Formulation Using Sensitivity Factors

A transmission topology control (TC) framework for production cost reduction based on a shift factor (SF) representation of line flows is proposed. The framework can model topology changes endogenously while maintaining linearity in the overall Mixed Integer Linear Programming (MILP) formulation of the problem. In large power systems it is standard practice to optimize operations considering few but representative contingency constraints. Under these conditions and when tractably small switchable sets are analyzed, the SF framework has significant computational advantages compared to the standard B

Security-Constrained MIP Formulation of Topology Control Using Loss-Adjusted Shift Factors

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Shift Factor-Based SCOPF Topology Control MIP Formulations With Substation Configurations

alternative used so far in TC research. These claims are supported and elaborated by numerical results on full models of PJM with over 13,000 buses. We finally present analytical investigations on locational marginal price (LMP) computation in our SF TC framework and their relation to LMPs computed for problems without TC. Also, we discuss practical implementation choices such as sufficient conditions on lower bounds that allow selection of large numbers employed in the MILP formulation.

Market Based Intraday Coordination of Electric and Natural Gas System Operation

Following up on our previous work, we formulate a linear, loss-adjusted, shift factor mixed integer program (MIP) to co-optimize generation and network topology. While both the Bθ and shift factor topology control (TC) formulations lead to production cost saving, we showed that the shift factor formulation performs better for small to medium switch able sets. In this paper we extend the original TC shift factor formulation to include marginal losses. We derive loss-adjusted shift factors and show that both losses and flows can be updated linearly with a change in topology by taking advantage of flow-canceling transactions (FCTs). The marginal loss formulation we present in this paper closely resembles that of most market engines. In doing so, we aim to better approximate the AC power flow and to generate topologies leading to production cost savings while maintaining feasibility subject to AC security constrained power flow (SCOPF) constraints.

Financial Transmission Rights in Changing Power Networks

Topology control (TC) is an effective tool for managing congestion, contingency events, and overload control. The majority of TC research has focused on line and transformer switching. Substation reconfiguration is an additional TC action, which consists of opening or closing breakers not in series with lines or transformers. Some reconfiguration actions can be simpler to implement than branch opening, seen as a less invasive action. This paper introduces two formulations that incorporate substation reconfiguration with branch opening in a unified TC framework. The first method starts from a topology with all candidate breakers open, and breaker closing is emulated and optimized using virtual transactions. The second method takes the opposite approach, starting from a fully closed topology and optimizing breaker openings. We provide a theoretical framework for both methods and formulate security-constrained shift factor MIP TC formulations that incorporate both breaker and branch switching. By maintaining the shift factor formulation, we take advantage of its compactness, especially in the context of contingency constraints, and by focusing on reconfiguring substations, we hope to provide system operators additional flexibility in their TC decision processes. Simulation results on a subarea of PJM illustrate the application of the two formulations to realistic systems.

Price Suppression and Emissions Reductions with Offshore Wind: An Analysis of the Impact of Increased Capacity in New England

This paper outlines the design of an intraday market-based mechanism for coordinated scheduling of gas-fired electric generation, intra-day natural gas purchases, sales and deliveries, and underlying pipeline operation. The mechanism is based on an exchange of physical and pricing data between participants in each market, with price formation in both markets being fully consistent with the physics of energy flow. In organized nodal electricity markets, prices are consistent with the physical flow of electric energy in the power grid because the economic optimization used to clear the market accounts for the physics of power flows. In the gas system, the proposed physical operation and pricing will be based on the transient optimization approach that accounts for physical and engineering factors of pipeline hydraulics and compressor station operations. The paper provides theoretical foundations for the market mechanism.

Applicability of topology control algorithms (TCA) to a real-size power system

Many restructured power markets rely on Financial Transmission Rights (FTRs). FTRs are financial contracts that entitle the holder to a stream of revenues (or charges) based on the day-ahead hourly congestion price difference across an FTR related energy path. Holders obtain FTRs through an auction mechanism relying on the solution of a specially formulated OPF problem. FTR holders then receive or make payments based on the outcome of Day Ahead (DA) energy market. Known FTR properties (revenue adequacy) [1] guarantee that if the auction OPF and the DA market have the same network topology, congestion rent collected in the DA market will be sufficient to pay all FTR holders. DA market topology almost always deviates from the auction topology. This may create underfunding problems. We propose a solution to topology-driven underfunding using Topology Reconfiguration Rights (TRRs) -- financial transactions corresponding to topology changes. Combinations of FTRs and TRRs guarantee revenue adequacy.

Economic Optimization of Intra-Day Gas Pipeline Flow Schedules using Transient Flow Models

Offshore wind provides multiple benefits both in terms of economic savings to consumers and reduction in environmental residuals. The current paper uses a state-of-of-the-art software system, pCloudAnalyticsTM to evaluate multiple scenarios of the incorporation of offshore wind assets in the New England electric power system ranging in size from 100MW to 1200MW. The analysis is focused on the benefits to consumers -- the price suppression impacts -- of increasing quantities of offshore wind. The analysis provides a detailed evaluation of the locational marginal price (LMP) impact of increasing MW of offshore wind for a single study year, 2015. In addition the analysis tracks and presents the reductions in air emissions that result from incorporation of increased quantities of offshore wind in the New England system.