Wideband line/cable models for real-time and off-line simulations of electromagnetic transients

The development of a mathematical model for the electromagnetic simulation of power transmission lines and cables is described in this thesis along with its hardware and software implementation. This model is intended for real-time and accelerated-time simulation of electromagnetic transients (EMTs) occurring in power-supply networks. The developed model fills an existing gap in real-time simulation practice and, in comparison with those ones currently available to power-system analysts; it represents a substantial improvement in terms of stability and of computational-efficiency.;The proposed line model is based on the Wide Band (WB) or Universal Line Model (ULM) which, because of its accuracy and generality, is widely adopted as the referent. These two features of the ULM follow from its ability to account completely and effectively for all the frequency-dependent effects of line parameters. Nevertheless, the original ULM has been reformulated and restructured here to meet the stringent requirements for real-time simulations.;The structure of the new model facilitates the partition of large networks in sub-blocks that can be simulated in parallel on a multiprocessor cluster. One feature of the ULM that is preserved in the new model is the rational representation of the characteristic admittance and the propagation function matrices, both obtained directly in the phase domain by using the Vector Fitting (VF) or the Weighted Vector Fitting (WVF) software utilities. One issue requiring special consideration is the handling of the complex state variables produced by complex poles that often arise when using VF or WVF. The standard approach to this is the direct one consisting in the treating of all internal states as complex. In the case of real states, the imaginary parts simply are zeros. In the case of complex states, the imaginary parts must cancel each other since complex poles and complex states occur in conjugate pairs. Clearly, form the computational standpoint this standard approach reports a large number of trivial and redundant operations and thus, from the computational standpoint, it is deemed here as highly inefficient. The alternative proposed in this thesis is the handling of all state variables in real Arithmetic. Two methods for doing this are developed, implemented and tested in this thesis.;Method 1 consists in discarding one state out of each conjugate pair, since it is demonstrated in this thesis that both states convey the same information. Each of the remaining complex states is then treated as a pair of mutually-coupled real states. By doing this, the.