Session 13: Transmission Investment Policies
Transmission Costs Allocation Based on Optimal Re-Dispatch
Polytechnic of Porto, Portugal
Congestion management of transmission power systems has achieve high relevance in competitive environments, which require an adequate approach both in technical and economic terms. This paper proposes a new methodology for congestion management and transmission tariff determination in deregulated electricity markets. The congestion management methodology is based on a reformulated optimal power flow, whose main goal is to obtain a feasible solution for the re-dispatch minimizing the changes in the transactions resulting from market operation. The proposed transmission tariffs consider the physical impact caused by each market agents in the transmission network. The final tariff considers existing system costs and also costs due to the initial congestion situation and losses. This paper includes a case study for the 118 bus IEEE test case.
Optimal Voltage Scheduling Procedure for Croatian Power System
1HEP Operator prijenosnog sustava, Croatia; 2HEP Operator prijenosnog sustava, Croatia; 3HEP Proizvodnja, Croatia
An optimal voltage scheduling procedure for shortterm reactive planning phase is proposed in the paper. Optimal voltage schedule is determined in the day-ahead or hour-ahead planning phase as a result of an optimal power flow algorithm. Optimal power flow objective is a minimization of transmission losses with respect to power system security constraints. Optimal power flow inputs are power system load forecast and generation schedule, while the outputs of an optimization algorithm are voltages in generator’s nodes, tap positions of on-load tap changing transformers and reactive power engagement of network compensation devices. The optimization algorithm is tested on Croatian transmission network. Voltage setting procedure is proposed in the paper. Architecture of the system for remote adjustment of control variables is described.
Distributed Remedial Action Strategy for a 500-kV AC Transmission System
Fichtner GmbH & Co KG, Germany
Generally, EHV transmission system reinforcement is unable to keep pace with developments at the generation level, which are subject to manifold uncertainties, especially in deregulated markets. Where there is a significant time gap between network developments and generation developments, it is necessary for the power system to be operated during peak load in an “alert” state, which conflicts with basic security rules, such as single contingency withstand. Among the lines of defense for avoiding further supply deterioration are event- or responsedriven distributed Remedial Action Schemes (RAS), which are activated from the system control centers if the power flow on a transmission line section exceeds a predefined critical value. RAS can be practically implemented faster than a fully fledged Static and Dynamic Security Assessment embedded in the real-time environment of the Energy Management System, and are at the same time a wholly satisfactory solution for simple transmission system configurations. The paper presents the study methodology and conceptual design for distributed RAS projects currently under implementation in two similarly structured 500- kV power systems in developing countries.
Optimization of Power System Controller Parameters Using Eigen Value Sensitivity and Linear Programming
1Department of Electrical and Computer Engineering, College of Engineering, Dhofar University, Salalah, Oman; 2Department of Electrical and Computer Engineering, College of Engineering and Architecture, American University of Beirut Beirut, Lebanon; 3Electrical Power and Machines Department, Faculty of Engineering, Cairo University, Giza, Egypt
This paper presents a modified technique for the tuning of power system controller parameters in order to improve the power quality and dynamic stability of the system. The technique uses symbolic Eigen value sensitivity analysis and linear programming approach to determine the optimum value of controller parameters in the system. The main objective function aims to shift critical Eigen values to the left of the imaginary axis in the s-plane, as far as possible. The proposed method presents new constraints including a new formula for convergence and a controlling parameter to reduce the effect of numerical approximation resulting from the linearization of the objective function. Proper selection of the most effective parameters to be tuned is also performed. The proposed technique is general, effective and simple to apply using the developed MATLAB-SIMULINK software program which has a friendly user interface. A case study is considered which is a single synchronous machine connected to an infinite bus-bar through a transmission line equipped with a Power System Stabilizer (PSS). Simulation results verify the validity of the proposed technique in enhancing system stability.
Possible Savings in Electricity Transmission Using Wide Area Monitoring Technologies in Croatian Power Transmission Network
1HEP OPS d.o.o. Prijenosno područje Rijeka, Croatia; 2Fakultet elektrotehnike i računarstva Zagreb, Croatia
Since the economic aspect arose over the technical regarding the development of the infrastructure of electrical power systems, new guidelines and ideas began to emerge particularly in terms of control, measurement and protection of the system. This paper describes concept and functions of wide area monitoring, protection and control in the real time in order to reduce costs that could be caused by future investments in building the infrastructure of electrical power system. Also, the paper considers the aspects of implementation of renewable energy sources on the example of wind farm Vrataruša and describes the conceptual design of automatic control for that part of the power transmission network.
The Economic Analysis of Transmission Investment Policies
Royal Institute of Technology, Sweden
This paper defines and discusses three types of benefits for economic analysis of transmission investment policies. These benefits are termed (1) The Efficiency Benefit, (2) The Static Competition Benefit, and (3) The Dynamic Competition Benefit. To provide more insights to these benefits, an example system is studied. The results show that a transmission network service provider can and should use the transmission investment policies to improve the competition (static and dynamic) in the supply electricity industry. Further research is necessary to model the static and dynamic competition benefit in the process of transmission expansion planning.