Review of Methods to Calculate Congestion Cost Allocation in Deregulated Electricity Market

With maturing deregulated environment for electricity market, cost of transmission congestion becomes a major issue for power system operation. Uniform Marginal Price and Locational Marginal Price (LMP) are the two practical pricing schemes on energy pricing and congestion cost allocation, which are based on different mechanisms. In this paper, these two pricing schemes are introduced in detail respectively. Also, the modified IEEE-14-bus system is used as a test system to calculate the allocated congestion cost by using these two pricing schemes.

Reliability-based congestion pricing model under endogenous equilibrated market penetration and compliance rate of ATIS

A reliability-based stochastic system optimum congestion pricing(SSOCP) model with endogenous market penetration and compliance rate in an advanced traveler information systems(ATIS) environment was proposed. All travelers were divided into two classes. The first guided travelers were referred to as the equipped travelers who follow ATIS advice, while the second unguided travelers were referred to as the unequipped travelers and the equipped travelers who do not follow the ATIS advice(also referred to as non-complied travelers). Travelers were assumed to take travel time, congestion pricing, and travel time reliability into account when making travel route choice decisions. In order to arrive at on time, travelers needed to allow for a safety margin to their trip.The market penetration of ATIS was determined by a continuous increasing function of the information benefit, and the ATIS compliance rate of equipped travelers was given as the probability of the actually experienced travel costs of guided travelers less than or equal to those of unguided travelers. The analysis results could enhance our understanding of the effect of travel demand level and travel time reliability confidence level on the ATIS market penetration and compliance rate; and the effect of travel time perception variation of guided and unguided travelers on the mean travel cost savings(MTCS) of the equipped travelers, the ATIS market penetration, compliance rate, and the total network effective travel time(TNETT).

Transmission Use of System Charging for Differentiating Long-term Impacts from Various Generation Technologies

This paper proposes a novel transmission use of system(TUoS)charging method,which is able to 1)acknowledge the trade-offs between short-run congestion cost and long-run investment cost when justifying economic network investment,2)identify the impacts of different generation technologies on congestion cost and network investment,and 3)translate these impacts into economically efficient TUoS tariffs that differentiate generation technologies.An incremental capacity change from a generator will impact the congestion costs at each branch,which is then translated into the impacts on investment time horizons.The difference in the present values with and without the incremental change for a branch is its long-run incremental cost(LRIC).The final TUoS tariff for this generator is the sum of all LRIC triggered by its capacity increment.The proposed method is demonstrated on a modified IEEE 14-bus system to show its effectiveness over the traditional approach.Results show that it can provide cost-reflective TUoS tariffs for different generation technologies at the same sites by examining their respective impacts on congestion and investment.It thus can incentivize appropriate generation expansion to reduce congestion costs and ultimately network investment cost.