Network Investment Cost Research Articles

A Bilevel Approach to Transmission Expansion Planning Within a Market Environment

We present a bilevel model for transmission expansion planning within a market environment, where producers and consumers trade freely electric energy through a pool. The target of the transmission planner, modeled through the upper-level problem, is to minimize network investment cost while facilitating energy trading. This upper-level problem is constrained by a collection of lower-level market clearing problems representing pool trading, and whose individual objective functions correspond to social welfare. Using the duality theory the proposed bilevel model is recast as a mixed-integer linear programming problem, which is solvable using branch-and-cut solvers. Detailed results from an illustrative example and a case study are presented and discussed. Finally, some relevant conclusions are drawn.

Flexible transmission and network reinforcements planning considering congestion alleviation

A framework for obtaining an optimal network reinforcement scheme to jointly meet both long-term transmission capacity requirements as well as the alleviation of short- or medium-term congestion in a competitive power market is presented. A value-based network expansion strategy is formulated in which long-term network investment cost is justified by the long-term congestion cost saving. Network expansions and flexible AC transmission system (FACTS) device installations are investigated as possible alternatives for network reinforcement. These alternatives are considered separately as well as in different combinations. Two types of FACTS devices namely the phase shifter and the series compensator are explored for the purpose. The solution methodology is implemented using the generalised Benders decomposition technique in which the master problem is the network investment cost minimisation and the operational subproblem is the social cost minimisation in network constrained power dispatch. Case studies have been carried out on the modified IEEE 24-bus system to illustrate the features of the proposed technique and to demonstrate the ability of the technique to produce good network reinforcement schemes under various conditions.

Access pricing and investment with stochastically growing demand

This paper examines the effect of access charges on firms' incentives to invest in a network facility with a stochastically growing demand. An access-to-bypass equilibrium is characterized in terms of an access charge and a level of network investment cost. In the equilibrium, a leader first enters a market by building a new network. Then a follower makes a sequential investment for the construction of an additional network after accessing the incumbent's network. In an open access environment, we confirm that the incentive for preemption can be enhanced by an increase in the access charge.

Urban Distribution Network Investment Criteria for Reliability Adequacy

Distribution planning is a complex decision-making process usually formulated as a multiobjective optimization problem. The optimal solutions represent the best possible tradeoff between network investment costs, energy loss costs, and reliability costs. In the context of optimal distribution planning, we study the dependence of backup-circuit investment decisions on the cost of energy not supplied. The study results establish investment decision-making criteria for reliability adequacy. The criteria may be used to assess what is a reasonable investment on backup circuits and to evaluate the adequacy of existing backup circuit with respect to the valuation of energy not supplied.

The impact of mobility on UMTS network planning

In this paper the impact of terminal mobility on UMTS radio network planning is investigated. This impact stems from (i) the more severe signal-to-interference ratio requirements that apply in case of higher velocities, due to the combined effects of multipath propagation, Doppler shifts and power control imperfections; and (ii) the greater radio resource reservation regarding handovers that is required in case of higher velocities, in order to keep the dropping probability below a prespecified target value; as a consequence, fresh call blocking increases, inducing a need for denser site planning. An analytical approach is presented to evaluate the impact of both mobility-related aspects on network planning, performance and investment costs. The principal strength of the presented model and approach lies therein that it is simple enough to allow a computationally relatively inexpensive performance evaluation and optimisation, yet sufficiently realistic to provide valuable qualitative insight for network planning purposes. Numerical results identify terminal mobility as a key property that must not be disregarded in the radio network planning process, while the deployment of radio resource reservation is shown to be very effective in reducing both call dropping and investment costs.

Economic optimization of the water reuse network in batch process industries

Water reuse has proved to be an efficient way to reduce freshwater demand and wastewater generation in process industries. In this paper, a methodology for minimizing the costs associated to water management in batch process industries is presented. This work is based on a previous methodology for freshwater demand minimization, which has been extended to the economical aspects of water management: cost associated to freshwater supply and conditioning, wastewater treatment and disposal, as well as water reuse network investment and operation costs. Water reuse network design is optimized from the economical point of view, minimizing the operation and investment costs associated to the water use.

CHOPIN, a heuristic model for long term transmission expansion planning

This paper describes the long term transmission expansion planning model CHOPIN. In CHOPIN, the network expansion is formulated as the static optimization problem of minimizing the global annual cost of electricity production, which is obtained as the sum of the annualized network investment cost, the operation cost and the reliability cost. The solution method takes advantage of the natural decomposition between the investment and operation submodels. The investment submodel is solved by a new heuristic procedure that in practice has invariably yielded the optimal plan. At the operation level CHOPIN optimizes over a multiplicity of scenarios which are characterized by the demand, the hydraulicity and the availability of components. The network is represented by any one out of four options: DC load flow (DCLF), transportation model and two hybrid models. Any of these models may consider the ohmic losses. The model is very efficient computationally; this fact was verified on rest examples, as well as on the actual transmission expansion planning of the Spanish system. >