W.W. Price

Bio: W.W. Price is an academic researcher from General Electric. The author has contributed to research in topics: Electric power system & Power system simulation. The author has an hindex of 7, co-authored 9 publications receiving 527 citations.

Load modeling for power flow and transient stability computer studies

Abstract: A novel method is presented for preparing load models for power flow and stability studies. The LOADSYN load model synthesis software package transforms data on load class mix, composition, and characteristics into the form required for commonly used flow and transient stability simulation programs. Typical default data have been developed for load composition and characteristics. The load-modeling techniques used in this software and results of initial testing are described. Significant improvements in simulation accuracy are demonstrated. >

Aggregation of Induction Motors for Transient Stability Load Modeling

Abstract: An investigation of several methods for aggregating induction motors is described. The accuracy of the methods is compared using frequency-domain techniques. A new method involving the use of one or two aggregate motors is described and shown to be superior to other methods.

Multiple time-scale power system dynamic simulation

Abstract: A new program, EXSTAB (extended time-scale stability) has been developed for representing a wide variety of power system performance problems, from transient stability through long-term dynamics and voltage instability. The capability of the program includes multiple execution modes and automatic step size selection to address conflicting goals of accuracy and efficiency. The modeling includes a broad range of apparatus to provide the needed time-scale representation (four orders of magnitude). Models for automatic generation control, plant characteristics and control, voltage and reactive power control, static and dynamic loads, and protective relaying for apparatus and system connections are provided. Technologies were developed to perform analysis of voltage stability and prediction of peak power transfer to avoid voltage collapse. >

Testing of the Modal Dynamic Equivalents Technique

Abstract: Several techniques have been proposed in the literature for constructing dynamic equivalents of power systems for use in stability studies. These techniques exist primarily as research tools and their applicability for use in large scale production studies has not been clearly established. One of the techniques that appears to be promising is the 'modal analysis' approach developed by the General Electric Company for Electric Research Council project RP90-4. This paper describes the investigations carried out to evaluate the effectiveness of this approach using a realistic power system model.

Dynamic equivalents from on-line measurements

Abstract: This paper presents the results of a feasibility study of a technique for identifying dynamic equivalents of portions of a power system from measurements made only within a restricted Study System without intentional perturbation of the system. The Maximum Likelihood technique is used to identify parameter values for a specified equivalent structure which is suitable for direct use in standard transient stability programs. The identifier was tested using measurements from simulations tuned to match field measurements. The field measurements, identification algorithm, and program test results are described. The expected benefit of this technique is in overcoming a major block in the development of an on-line technique for the evaluation of transient stability contingencies by power system operators.

Standard load models for power flow and dynamic performance simulation

Abstract: The authors recommend standard load models for power flow and dynamic simulation programs. The goal of this paper is to promote better load modeling and advanced load modeling, and to facilitate data exchange among users of various production-grade simulation programs. Flexibility of modeling is an important consideration. For transient stability, longer-term dynamics, and small-disturbance stability programs, the authors recommend the structure of multiple load types connected to a load bus. Load types are static including discharge lighting, induction motors, synchronous motors, and transformer saturation. For each load type, multiple models may be connected to the bus. For longer-term dynamics programs, a model for LTC transformers is also recommended.

Flexible AC transmission systems (FACTS)

Abstract: The paper reviews literature which addresses the application of Flexible AC Transmission System (FACTS) concepts to the improvement of Power System utilisation and performance. It summarises literature on using high speed thyristor based control of HVAC power system elements to enhance the power carrying capacity of existing transmission circuits without compromising reliability. It describes a study system representative of existing power systems that has been developed to evaluate the economic and technical issues of loading transmission lines to their thermal limits. Considered are two scenarios, a multi-line corridor and a long radial interconnection, where the issues addressed are transient and dynamic stability, power flow control, reactive support and voltage stability. A benchmark system is developed to validate performance of die more simple devices. It is concluded that FACTS devices have the potential to significantly increase system stability margins thereby increasing loading capabil...

Sensitivity of the loading margin to voltage collapse with respect to arbitrary parameters

Abstract: Power system loading margin is a fundamental measure of a system's proximity to voltage collapse. Linear and quadratic estimates to the variation of the loading margin with respect to any power system parameter or control are derived. Tests with a 118-bus system indicate that the estimates accurately predict the quantitative effect on the loading margin of altering the system loading, reactive power support, wheeling, load model parameters, line susceptance and generator dispatch. The accuracy of the estimates over a useful range and the ease of obtaining the linear estimate suggest that this method will be of practical value in avoiding power system voltage collapse.

Voltage instability: phenomena, countermeasures, and analysis methods

Abstract: A power system may be subject to (rotor) angle, frequency or voltage instability. Voltage instability takes on the form of a dramatic drop of transmission system voltages, which may lead to system disruption. During the past two decades it has become a major threat for the operation of many systems and, in the prevailing open access environment, it is a factor leading to limit power transfer. The objective of this paper is to describe voltage instability phenomena, to enumerate preventive and curative countermeasures, and to present in a unified and coherent way various computer analysis methods used or proposed.

Composite load modeling via measurement approach

Abstract: The accuracy of the load model has great effects on power system stability analysis and control. Based on our practice in China on modeling load from field measurements, this paper systematically develops a measurement-based composite load model. Principles guiding the load modeling practice are discussed based on detailed analysis on stochastic characteristics of the modeling procedure. The structure of the measurement-based composite load model is presented. A multicurve identification technique is described to derive parameters. The generalization capability of this built load model is also investigated in this paper. Two cases are studied to illustrate the accuracy of the developed load model on describing the load dynamic characteristics in the actual power system.