Power System Resources Research Articles

Decentralised coordination of power system operation using dual evolutionary programming

This paper proposes a decentralised coordination framework for operating power systems with dispersed generation and energy storage. It then develops a novel decentralised approach for calculating the system optimal operation of resources with intertemporal links. The method combines elements of dynamic programming with evolutionary programming. Each power system resource evolves a 'future benefit' function that describes the impact of its own possible decisions on future power system operation. This 'dual evolutionary programming' approach can handle complex resource models and objective functions. It is shown to be computationally faster than discrete dynamic programming for a number of power system problems with multiple storage resources.

A new unit commitment method

This paper introduces a new unit commitment method based on a decommitment procedure for solving the power system resource scheduling problem. From an initial schedule of all available units committed over the study period, a 'one-at-a-time' unit decommitment is accomplished by dynamic programming according to some specified economic criteria. The decommitment process continues until no further reduction in total cost is possible, or the unit schedules of two consecutive iterations over the time period remain unchanged without any violation of the spinning reserve constraint. Two criteria for decommiting a unit are introduced and described in detail. Comparisons of the proposed unit commitment method with the Lagrangian relaxation (LR) approach and Fred Lee's sequential unit commitment method (SUC) demonstrate the potential benefits of the proposed approach for power system operations planning.

96/03904 Modelling and simulation of the operational impacts and value of distributed renewable resources in electric power systems

96/03904 Modelling and simulation of the operational impacts and value of distributed renewable resources in electric power systems

A practical resource scheduling with OPF constraints

This paper presents an efficient approach to short term power system resource scheduling based on the augmented Lagrangian relaxation method. The problem is divided into two stages, the commitment stage and the constrained economic dispatch stage. The proposed mathematical model incorporates optimal power flow (OPF) constraints in the unit commitment stage. By OPF constrains, the authors refer to the relevant active power constraints that are incorporated in the constrained economic dispatch stage (i.e. transmission capacity constraints, fuel and various regulated emission requirements). The inclusion of OPF constraints in the commitment stage will improve the feasibility of the constrained economic dispatch solution. Other unit commitment constraints such as spinning and operating reserve requirements, power balance as well as other relevant local constraints (i.e. unit ramping rates, upper and lower generation limits, minimum up and down times) are taken into account in the proposed model. As a larger number of constraints are dealt with, a more rigorous method is introduced for updating Lagrange multipliers to improve the solution convergence. A software package which addresses energy management systems requirements is developed and tested.

Integrating price-based resources in short-term scheduling of electric power systems

This paper discusses the application of a Lagrangian relaxation algorithm for solving short-term power system resource scheduling problems in the presence of endogenously priced resources. The authors demonstrate how such resources can be incorporated into the scheduling model as opposed to the prevailing practice of activating them through post-dispatch price signals derived from the short term scheduling of resources directly controlled by the electric utility. Through a simulation study, the authors compare operations and costs of integrated scheduling to those resulting from the post-dispatch approach. Their analysis demonstrates that integrated scheduling can produce significant improvements. >

Inter-utility communications within WSCC

The development of real-time interutility data communications capabilities has resulted in many implementations in the western United States. The current state of these implementations and the future plans for additional capabilities spanning the entire Western Systems Coordinating Council (WSCC) are presented. In 1982, the WSCC formed a group to develop a protocol and a set of guidelines for real-time interutility data exchange. All the major utilities within the WSCC now have or are planning implementations based on the guidelines. Other implementations outside the WSCC are discussed. The impetus for this move is economic benefits realized by reduced hardware installation, better power system modeling that allows optimal use of existing resources, visibility outside a utility's control area, better restoration coordination, and the ability to quickly match power system resources to markets at mutually beneficial prices.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>