Quantifying TRM by Modified DCQ Load Flow Method

In the integrated power system network uncertainty can occur at any time. The transmission reliability (TRM) margin is the amount of transmission capacity that guarantees that the transmission network is protected from instability in the operating state of the system. The calculation of the available transfer capacity (ATC) of the transmission reliability margin should be included in a deregulated power system to ensure that the transmission network is safe within a fair range of uncertainties that arise during the power transfer. However, the TRM is conserved as a reliability margin to reflect the unpredictability of the operation of the electric system. Besides, the system operator (SO) utilizes the TRM value during unreliability by adjusting the ATC value some amount up or down to account for errors in data and uncertainty in the model. This paper describes a technique for TRM estimation by modified DCQ load flow method considering VAR transfer distribution factor. The main focus of this study is to get a new approach to determine TRM by incorporating with ATCQ considered reactive power and sensitivity w.r.t ATC considered voltage magnitude. This technique is applied to the IEEE 6 bus system, and results are compared with previous results for validation. The technique leads to more exact and secure estimates of transmission reliability margin

ATC Enhancement With FACTS Devices Considering Reactive Power Flows Using PTDF

In the present day world power system deregulation is at its full stretch. In this deregulated environment there is a clear need for adequate computation of ATC which is currently being given at most importance. The insertion of FACTS devices in electrical systems seems to be a promising strategy to enhance ATC. In this paper, the viability and technical merits of boosting ATC using TCSC are analyzed. The methods used for determining ATC are linear methods, which are based on MVA loading of the system considering system thermal limit constraints, neglecting bus voltages and static collapse. Power Transfer Distribution Factors, commonly referred to as PTDFs, express the percentage of a power transfer that flows on a transmission facility. They are used to determine the maximum ATC that may be available across the system without violating line thermal limits. The effect of reactive power flows in line loading is not considered in linear ATC which is a major limitation. This paper describes a fast algorithm to incorporate this effect. In this paper the line post transfer complex flow is estimated based on exact circle equation and then ATC is evaluated using active power distribution factors. The effectiveness of the proposed method is successfully demonstrated on IEEE 30-Bus system.DOI:http://dx.doi.org/10.11591/ijece.v3i6.392

ACPTDF for Multi-transactions and ATC Determination in Deregulated Markets

Abstract—Available transfer capability in the transmission network has become essential quantity to be declared well in advance for its commercial use in a competitive electricity market. Its fast computation using DC load flow based approach is used worldwide for on line implementation. Many authors have proposed the ATC calculation based on DC/AC load flow approach. In this paper, AC PTDF based approach has been proposed for multi-transaction cases using power transfer sensitivity and Jacobian calculated with three different methods. The methods can be implemented for any number of transactions occurring simultaneously. The results have been determined for intact and line contingency cases taking multi-transaction/simultaneous as well as single transaction cases. The main contributions of the paper are: (i) ATC determination for multi-transactions environment, (ii) ATC determination and comparison with three approaches of PTDF calculations, (iii) LODFs with line contingency cases for multi-transaction environment and thereby ATC determination. The results have also been obtained with DC method for comparison. The proposed method have been applied for IEEE 24 bus RTS. Keywords: Available transfer capability, AC load flow, AC power transfer distribution factors , line outage contingency, line outage distribution factors, multi-transactions, simultaneous transactions.DOI:http://dx.doi.org/10.11591/ijece.v1i1.6

Consideration in calculating transfer capacity

The computation of total transfer capability (TTC) is a significant task in the new power system deregulated environment. In this paper, assumptions and considerations used throughout the study are indicated first, a framework for TTC calculation is then presented. A 4-bus test power system is used to demonstrate TTC calculation followed by further discussion.published_or_final_versio

Application of Cubic Spline Interpolation Technique in Power Systems: A Review

In this chapter, a comprehensive review is made on the application of cubic spline interpolation techniques in the field of power systems. Domains like available transfer capability (ATC), electric arc furnace modeling, static var. compensation, voltage stability margin, and market power determination in deregulated electricity market are taken as samples to illustrate the significance of cubic spline interpolation

Determination of available transfer capability (ATC) in a competitive electricity market using Nigerian 3-bus and 14-bus power network as case study

In the deregulated power system, competition arises in generation and distribution but the transmission corridor remains the same for transferring power. Every operator wants to maximize profit, as such the number of transaction increases. This may cause congestion in transmission network. To avoid this, every operator should know the value of available transfer capability (ATC) before every transaction. Determination of ATC is a complex task which has to be done at periodic intervals for each source and sink pairs. Though there are many methods available to assess ATC, the most accurate method is repeated power flow using newton raphson (RPFNR). In this research work, RPFNR approach was applied on both 3-bus and 14 bus network by modeling and simulation using Power World Simulator (PWS). ATC between nodes and areas for both networks were determined. The error difference between ATC obtained from both procedures was negligible. A 14-bus system was further modeled, and ATC between nodes and areas were determined.Keywords: ATC, RPFNR, PWS, bus, grid, deregulated , contingenc

Available transfer capability evaluation by decomposition

A central issue of running a successful electric power market is the evaluation of the associated available transfer capability (ATC) representing the room available for trading. Due to the need to post and update ATC values at regular intervals, the underlying calculation method should be moderately fast with acceptable accuracy. This paper proposes the evaluation of ATC by using Benders decomposition. The problem is first broken up into a master problem expressing the steady state operating condition and subproblems for the contingent conditions. Each subproblem is solved independently and a linear constraint using Lagrange multipliers of the subproblem is generated and added to the master problem. The proposed decomposition scheme is applied to IEEE 30 bus system with satisfactory results as compared with the distribution factors method.published_or_final_versio

Interior point based optimal voltage stability, oscillatory stability and ATC margin boundary tracing

This dissertation proposes a general framework for the power system stability margin boundary tracing and optimization. The proposed framework combines interior point algorithm and continuation method seamlessly to provide the optimal control configuration for any feasible system margin. The maximum stability margin for any given control configuration can be derived by interior point based optimal margin boundary tracing (IP-OMBT) while minimizing the corresponding control costs. From the first stability margin boundary point to the maximum margin boundary point, a series of margin levels with corresponding minimal control cost structure are generated. The margin benefit and the corresponding optimal control costs are visualized along the margin boundary. The proposed method is flexible enough to be modified to trace various other security margin boundaries. In addition, direct ATC tracing and optimal ATC tracing package are developed to address voltage/oscillatory stability related ATC problems. Numerical examples with New England 39 buses system are presented to demonstrate the versatility and practical usefulness of IP-OMBT package

Airborne Directional Networking: Topology Control Protocol Design

This research identifies and evaluates the impact of several architectural design choices in relation to airborne networking in contested environments related to autonomous topology control. Using simulation, we evaluate topology reconfiguration effectiveness using classical performance metrics for different point-to-point communication architectures. Our attention is focused on the design choices which have the greatest impact on reliability, scalability, and performance. In this work, we discuss the impact of several practical considerations of airborne networking in contested environments related to autonomous topology control modeling. Using simulation, we derive multiple classical performance metrics to evaluate topology reconfiguration effectiveness for different point-to-point communication architecture attributes for the purpose of qualifying protocol design elements