Showing papers on "Power system simulation published in 1984"
TL;DR: In this paper, a sequential procedure for coordinated stabilization of a multimachine power system with arbitrary complexity of the system model is presented, where the most effective machine to be equipped with a power system stabilizer is identified using eigenvalue analysis.
Abstract: The paper presents a sequential procedure for coordinated stabilization of a multimachine power system with arbitrary complexity of the system model. The most effective machine to be equipped with a power system stabilizer is identified using eigenvalue analysis. The selection is based on the sensitivity of critical eigenvalues to increases in the coefficient of a damping term which is inserted in each equation of motion, in succession. The method is applied to a three-machine system and simulation studies show appreciable improvements in the small disturbance stability of the system.
72 citations
TL;DR: A class of self-tuning regulators called Dual-rate Sampling Self-Tuning regulators which use a dual-rate sampling model of the power system are described in this paper.
Abstract: A recent trend in power system operation is towards computerised control and management. One class of digital adaptive regulators called self- tuning regulators is suitable for this purpose. In synchronous generator control a conflict arises between the small sampling interval necessary to track the dynamics and large computation time required by the process computer. A dual-rate sampling model is suggested to alleviate this problem. A class of self-tuning regulators called Dual-rate Sampling Self-Tuning regulators which use a dual-rate sampling model of the power system are described in this paper. Simulation results obtained are used to evaluate the merits, usefulness and viability of the proposed regulator.
63 citations
TL;DR: In this paper, a measure of the time frames is defined and evaluated for power system components in the EPRI RP 1208 Transient/Midterm Stability Program, and the limitations and capabilities of stability simulation to properly support the range of time frames are discussed.
Abstract: There is considerable interest in expanding the capability of transient stability simulation to extend the time range of simulation and to add more power system components. The EPRI projects RP 745 and RP 1208 extended transient stability simulation to the mid-and long-term range. Additional power system components have added both high-speed dynamics (dc converters, generator subtransients) and very low speed effects (boiler dynamics, AGC controls). This paper addresses the interfacing of the wide range of time frames. A measure of the time frames is defined and evaluated for power system components in the EPRI RP 1208 Transient/Midterm Stability Program. The limitations and capabilities of stability simulation to properly support the range of time frames is discussed. This work has been supported, in part, by EPRI projects RP 745, RP 1208 and RP 1469.
39 citations
TL;DR: In this paper, a general approach to solve the problem of unit commitment and fossil fuel allocation is presented, which is tested on a system with 60 units and some characteristic features of the optimal solution are discussed.
Abstract: A general approach will be presented to solve the problem of unit commitment and fossil fuel allocation. Multi-fuel units allowed to burn a variable mixture of different fuel types, with fuel dependent input-outpat models are considered in the optimization process. In addition, a variety of contractual limitations and physical constraints may be included. The approach has been tested on a system with 60 units. Results will be presented. Some characteristic features of the optimal solution will be discussed. From these, simplified approaches may be derived in order to solve dedicated problems.
34 citations
TL;DR: In this article, a simulation procedure for bulk power system reliability evaluation is presented, where the operation of the system under forced or scheduled outages of circuits and/or units is simulated via a stochastic load flow.
Abstract: This paper presents a simulation procedure for bulk power system reliability evaluation. The operation of the system under forced or scheduled outages of circuits and/or units is simulated via a stochastic load flow. An efficient stochastic load flow methodology is presented, which computes circuit loading and bus voltage probability distributions from a given load probability distribution. The output of the stochastic load flow is utilized to compute the conditional probability of system failure according to predefined criteria. Circuit overloads and bus undervoltages/overvoltages are utilized as system failure criteria. The frequency and duration method is employed to compute bulk power system reliability indices. Upper and lower bounds on the reliability indices are computed, which converge to the true values of the indices as the number of contingencies simulated increases. The paper presents simulation results with two systems: (a) a small 9-bus system to demonstrate data requirements, and (b) the 500 kV/230 kV system of Georgia Power Company to demonstrate the applicability of the method to actual systems.
33 citations
TL;DR: The optimal scheduling or unit commitment of power generation systems to meet a random demand involves the solution of a class of dynamic programming inequalities for the optimal cost and control law, which is studied in terms of a scheduling delay and the relative magnitudes of the costs of different units.
Abstract: The optimal scheduling or unit commitment of power generation systems to meet a random demand involves the solution of a class of dynamic programming inequalities for the optimal cost and control law. We study the behavior of this optimality system in terms of two parameters: (i) a scheduling delay, e.g., the startup time of a generation unit; and (ii) the relative magnitudes of the costs (operating or starting) of different units. In the first case we show that under reasonable assumptions the optimality system has a solution for all values of the delay, and, as the delay approaches zero, that the solutions converge uniformly to those of the corresponding system with no delays. In the second case we show that as the cost of operating or starting a given machine increases relative to the costs of the other machines, there is a point beyond which the expensive machine is not used, except in extreme situations. We give a formula for the relative costs that characterize this point. Moreover, we show that as the relative cost of the expensive machine goes to infinity that the optimal cost of the system including the expensive machine approaches the optimal cost of the system without the machine.
25 citations
TL;DR: This paper presents an iterative pole-removal method based on the least-squares fitting techniq% to synthesize RLC equivalent networks according to their specified driving-point function in the frequency domain.
Abstract: In power system simulation (by means of TNA or digital computer) equivalent networks can be used to reduce the simulation complexity. This paper presents an iterative pole-removal method based on the least-squares fitting techniq% to synthesize RLC equivalent networks according7 to their specified driving-point function in the frequency domain. The synthesized networks are composed of only passive components to represent the DC constant, complex poles as well as poles at zero and infinite. Poles are removed individually from the specified driving-point function applying the least-squares fitting with respect to the frequency domain around the relevant resonance. This algorithm converges quickly even for highly resistive systems.
24 citations
TL;DR: In this article, the authors evaluated coordinated active and reactive power modulation for centralized and decentralized DC power modulation and demonstrated that coordinated reactive power modulation not only improves the system damping but also alleviates the mode shifting problem during the modulation.
Abstract: Coordinated active and reactive power modulation is evaluated for centralized and decentralized DC power modulation. Linear analysis and simulation studies are made for different DC network configurations. Simulation studies made on a hybrid computer demonstrate that coordinated reactive power modulation not only improves the system damping but it also alleviates the mode shifting problem during the modulation.
20 citations
TL;DR: In this article, a vector processor was developed which made it possible to perform real-time dynamic calculations for a large-scale power system with a large number of buses and generators.
Abstract: Individual generator dynamic calculation method is tused in simulating severe power system disturbances, such as system separation due to faults or resynchronization. To speed up the sparse matrix calculations, a new vector processor was developed which made it possible to perform real time dynamic calculations for a large-scale power system. Test results proved that dynamics of a system with 186 buses and 44 generators could be calculated within one-third of the actual phenomenon time.
17 citations
TL;DR: In this paper, the authors proposed a new method that includes the effect of machine outage and non-linear nature of cost of production of energy in the simulation of energy storage devices in power systems for economic analysis.
Abstract: The simulation of energy storage devices in power systems for economic analysis has generally been attempted as a linear program formulation. This report suggests a new method that includes the effect of machine outage and non-linear nature of cost of production of energy. The probability density function (PDF) of hourly loads is the starting point of the method. The method has proposed the concepts of shifting the PDF to a "target" to honor the energy constraints and has shown that the modifications to the PDF can be easily obtained from the cumulative distribution function (CDF)
TL;DR: An appropriate computer architecture is described and new algorithms, suitable for such a structure, are presented and a high efficiency is achieved.
Abstract: Multiprocessors allow transient problems to be solved faster than before. An appropriate computer architecture is described and new algorithms, suitable for such a structure, are presented. When true parallel programs are written according to the computer modes of operation, a high efficiency is achieved.
TL;DR: In this paper, the authors describe the electric power engineering program at The Ohio State University (OSU), and its characteristic features in electric power systems, high voltage engineering, and electric machines area.
Abstract: This paper describes the electric power engineering program at The Ohio State University (OSU), and its characteristic features in the electric power systems, high voltage engineering, and electric machines area. The innovative features in laboratory courses are related to the existence and utilization of protective relays and test sets, a high voltage laboratory, scale model facilities (air models and electrolytic tanks), electronic motor controls, and dissectible machines. Several experiments are reviewed in detail, especially the operation of a mini power system. The computer applications area and the development of a power system research simulator are also reviewed.
TL;DR: In this article, the authors investigate the potential of rate allocation control as a tool for on-line emergency control, it is tested with a simulation program with detailed modeling of prime mover dynamics, nonlinear load flow, and conventional governors and voltage regulators.
Abstract: Rate allocation control is a feedback algorithm for dynamic rescheduling of power flows to alleviate transmission link overloads. For computation speed, the control algorithm uses simplifying approximations including linearization. To investigate the potential of rate allocation control as a tool for on-line emergency control, it is tested with a simulation program with detailed modeling of prime mover dynamics, nonlinear load flow, and conventional governors and voltage regulators. The test case is a realistic emergency scenario developed from a well-known power system upset. Two of the simulations are presented to demonstrate several features of the rate allocation control.
06 Jun 1984
TL;DR: In this paper, a discrete model approach is presented for the integration of the differential equations involved in power system transient performance simulation, which can be derived directly and analytically from the dynamic equations of the system dynamic elements, and the approach offers more precise and accurate solution than methods such as the implicit trapezoidal.
Abstract: A novel discrete model approach is presented for the integration of the differential equations involved in power system transient performance simulation. The models can be derived directly and analytically from the differential equations of the system dynamic elements, and the approach offers more precise and accurate solution than methods such as the implicit trapezoidal. Results obtained via the discrete model approach are compared with those using the implicit trapezoidal method and itemized breakdowns of the computational demands of power system simulation calculations are analyzed along with limitations on numerical stability.
TL;DR: In this article, a modular steamgenerator-and turbine-model for drum boiler systems is described with the help of which the dynamic behaviour of the different components/ such as economiser, evaporator, superheater, reheater and turbine can be calculated from the physical heat and mass flow balances.