Three-Phase Dynamic Simulation of Power Systems Using Combined Transmission and Distribution System Models

Abstract

Abstract--This paper presents a new method for studying electromechanical transients in power systems using three phase, combined transmission and distribution models (hybrid models). The methodology models individual phases of an electric network and associated unbalance in load and generation. Therefore, the impacts of load unbalance, single phase distributed generation and line impedance unbalance on electromechanical transients can be studied without using electromagnetic transient simulation (EMTP) programs. The implementation of this methodology in software is called the Three Phase Dynamics Analyzer (TPDA). Case studies included in the paper demonstrate the accuracy of TPDA and its ability to simulate electromechanical transients in hybrid models. TPDA has the potential for providing electric utilities and power system planners with more accurate assessment of system stability than traditional dynamic simulation software that assume balanced network topology.

Integrated transmission & distribution system modeling and analysis: Need & advantages

“…Solving a similar set of DAEs under network imbalance becomes challenging because at the interface of time and frequency domains, six phasor variables (three magnitudes and three angles) should be calculated from three time domain values. References [19]- [21] discuss this problem in detail and present a method for solving the problem which has been implemented in the Three Phase Dynamics Analyzer (TPDA) application of DEW.…”

“…The simulations are performed using power flow and dynamic simulation applications (TPDA) of DEW. Detailed discussion on the power flow analysis application used in DEW can be found in [17] while the theory behind TPDA, its key features, and validation with PSLF and ATP can be found in [19]- [21].…”

“…To simulate the dynamic response of the hybrid model, the approach discussed in [19] and [21] is used. The 10 synchronous generators connected to the transmission system are modeled using the GENROU model, while their exciters are modeled using the ST1A model.…”

Dynamic Co-Simulation Methods for Combined Transmission-Distribution System With Integration Time Step Impact on Convergence

“…In [15], a co-simulation framework by two independent EMT simulations with a time-delay compensation algorithm is proposed to improve the co-simulation accuracy, but is not suitable for large distribution networks. In [16], a novel threephase dynamic analyzer algorithm is presented that enables the study of electromechanical transients in unbalanced networks without using EMTP programs. The idea behind this approach is to accurately simulate electromechanical transients using 3-phase approach.…”

Modeling and Simulating Long-Timescale Cascading Faults in Power Systems Caused by Line-Galloping Events

“…On one hand, previous works usually ignore wind effects on power system operations when studying the dynamic process of wind affecting a power grid, and only the statistical data of line tripping results can be obtained [13]. On the other hand, power system numerical simulation has been developing rapidly over the past few decades [14], from simulating the physical dynamics of power grids to integrating economical (market) events [15,16]. It is hard to uncover the affecting mechanism between line galloping and power systems in the respective research, although it does offer valuable guidance regarding the defensive measures against extreme weather events.…”