John Michael Undrill

Construction of Power System lectromechanical Equivalents by Modal Analysis

This paper presents an analytical approch to the construction of power system dynamic equivalents for use in stability calculations and dynamic simulations. The method presented is capable of accurately representing the dynanlical effects of generator field and amortisseur windings, voltage regulators, and speed governors. Experimental evaluation of equivalents constructed by this method is reported in a companion paper.

Electromechanical Equivalent for Use in Power System Stability Studies

This paper describes the development of dynamic power system equivalents for use in stability studies of interconnected systems. The problem of electromechanical equivalencing is formulated, and a method of constructing electromechanical equivalents is described. The performance of these equivalents has been evaluated by a series of computational tests. Theoretical material pertaining to electromechanical equivalencing is presented in a companion paper.

Structure in the Computation of Power-System Nonlinear Dynamical Response

Methods are presented for simulating multimachine power-system dynamical response on the basis of Parks equations including the effects of an arbitrary number of circuits on the rotors of the synchronous machines. These methods allow a direct calculation treatment of effects that are neglected or treated only approximately in many power-system simulation programs, namely, amortisseur damping torques and subtransient saliency.

Nonlinear Hydro Governing Model and Improved Calculation for Determining Temporary Droop

The linear governing equations of L. M. Hovey are extended to describe the major nonlinearities of a hydro electric generating set. The resultant nonlinear governing model can be used to simulate the small and large signal transient response of an isolated generating set under any loading condition, and comparisons of such simulations with test results are given. The analysis of the paper demonstrates that Hoveys method of calculating temporary droop from a closed dashpot step response transient is inaccurate, and a corrected method is presented.

Automatic Sectionalization of Power System Networks for Network Solutions

This paper describes a method for the automatic optimized sectionalization of power transmission networks as required for the application of piecewise solution techniques. The optimality criterion is the minimization of the total computer core memory requirement for storage of the network impedance or admittance matrices.

Power System Stability Studies by the Method of Liapunov: I - State Space Approach to Synchronous Machine Modeling

This paper records the development of a synchronous machine model in the mathematical form required by most modem automatic control theorems. The model is based on a new expression for the constraint imposed on the machine by a general balanced 3-phase tee-form transmission system consisting of a step-up transformer, a shunt load, and a transmission line terminating at a bus of known voltage.

Generating unit model validation: WECC lessons and moving forward

This paper describes WECCs (formerly WSCC) experience in generator testing and model validation. WSCC introduced a generator testing requirement following failure of simulations to reproduce events that occurred in the summer of 1996 in the Western Interconnection. The benefits of generator testing have been indisputable. The generator model data has been improved significantly in many cases. It has also been recognized that testing alone may not provide all the information required for power plant modeling, and that the models need to reflect power plant operating practices.

Power System Stability Studies by the Method of Liapunov: II - The Interconnection of Hydro Generating Sets

The second method of Liapunov is used to investigate the optimum settings of certain governor and voltage regulator parameters of interconnected hydro-electric generating sets. The paper considers a 2-machine system with a simplified tie line representation, and a one-machine system including a detailed model of the generator and its interconnection to an infinite bus.

Correction to "Structure in the Computation of Power-System Nonlinear Dynamical Response"

Equations (10) and (20) of the above-named work (ibid., vol. PAS-88, pp. 1-6, January 1969) are corrected.