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As more generators and loads are integrated by power electronic converters with complicated controls, electromagnetic transients (EMTs) simulation becomes an important tool for studying dynamic characteristics of large‐scale power systems. To accelerate system‐level EMT simulations, a fine‐grained parallel algorithm on graphics processing units (GPU) is proposed. By decomposing the computational models of the EMT simulation into heterogeneous, homogeneous and network solution computations, the simulations are mapped into three unified GPU kernels. To incorporate control signals and non‐linear features of electrical components, heterogeneous computations are formulated as layered direct acyclic graphs (LDAG) of primitive operations. An LDAG kernel is designed to carry out theses primitive operations efficiently by grouped threads. Then, homogeneous computations for state updates of electrical components are modelled as sets of fused multiply‐add (FMA) operations, which are concurrently processed by an FMA kernel. Moreover, a hybrid network solution kernel is designed to solve the network equations, which can adaptively select dense or sparse solvers. Large‐scale test systems are created and simulated on an NVIDIA K20x GPU. The results show that the proposed GPU‐based EMT simulations are accurate and achieve 10x speedups over the CPU‐based ones. [ABSTRACT FROM AUTHOR]

Due to synchronization requirements related to the interfacing with external systems, digital real time simulators of electromagnetic transients for equipment testing employ a constant integration time step width for solving the network equations. Therefore, the network solution is only calculated at discrete and equidistantly spaced time instants while in reality the time domain is continuous. Changes in network structure that occur between the discrete solution points are generally not simulated exactly. This can lead to switching control mistakes and numerical problems. In this paper the novel Clock Synchronized Structure Changing concept, which allows the accurate and efficient simulation of structural changes at arbitrary time instants, is presented. Index Terms--Real time power system simulators, power electronic device modeling, HVDC systems, FACTS devices, EMTP solution techniques, switching processes.

As more generators and loads are integrated by power electronic converters with complicated controls, electromagnetic transients (EMTs) simulation becomes an important tool for studying dynamic characteristics of large-scale power systems. To accelerate system-level EMT simulations, a fine-grained parallel algorithm on graphics processing units (GPU) is proposed. By decomposing the computational models of the EMT simulation into heterogeneous, homogeneous and network solution computations, the simulations are mapped into three unified GPU kernels. To incorporate control signals and non-linear features of electrical components, heterogeneous computations are formulated as layered direct acyclic graphs (LDAG) of primitive operations. An LDAG kernel is designed to carry out theses primitive operations efficiently by grouped threads. Then, homogeneous computations for state updates of electrical components are modelled as sets of fused multiplyadd (FMA) operations, which are concurrently processed by an FMA kernel. Moreover, a hybrid network solution kernel is designed to solve the network equations, which can adaptively select dense or sparse solvers. Large-scale test systems are created and simulated on an NVIDIA K20x GPU. The results show that the proposed GPU-based EMT simulations are accurate and achieve 10x speedups over the CPU-based ones. [ABSTRACT FROM AUTHOR]

A major difficulty in multiphase cable modeling with traditional electromagnetic transient program like the EMTP is the synthesis of the frequency-dependent transformation matrix which relates modal and phase domain variables. This paper presents a new model (zCable) to represent the frequency-dependence of cable parameters directly in phase coordinates thus avoiding the problems related to frequency-dependent transformation matrices. The cable model is split into two parts: a constant ideal line section and a frequency-dependent loss section. A pi-correction is proposed to solve the problem of different traveling times in the ideal line section. The main advantage of the proposed model as compared to existing frequency-dependent transformation matrix models is the model's absolute numerical stability for strongly asymmetrical cable configurations and for arbitrary fault conditions. In addition, the model parameters are easy to obtain with robust algorithms and the model can be efficiently implemented in the context of a real-time PC-cluster simulator. [ABSTRACT FROM AUTHOR]

Presents models for current transformers and coupling capacitor voltage transformers suitable for real-time transient simulation. The current transformer algorithm; Coupling capacitor voltage transformer; Conclusions.

Comments on an article appearing in the April 2000 issue of 'IEEE Transactions on Power Delivery,' which dealt with frequency-dependent balanced transmission lines. Problem of low numerical resolution of the J. Marti model; Reformulation of the line equations.