Modified nodal analysis: an essential addition to electrical circuit theory and analysis

Wedepohl, L.M.; Jackson, L. T.

doi:10.1049/esej:20020301

Cited by 87 publications

(35 citation statements)

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“…For this purpose, the circuit shown in Figure 10 was programmed using the modified nodal circuit analysis method [20]. The experimental circuit is supplied from one end with two 25 kV AC sources with reverse polarity in each one.…”

Section: Experimental Simulationsmentioning

confidence: 99%

A Novel Ground Fault Identification Method for 2 × 5 kV Railway Power Supply Systems

et al. 2015

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Abstract:The location of ground faults in railway electric lines in 2 × 5 kV railway power supply systems is a difficult task. In both 1 × 25 kV and transmission power systems it is common practice to use distance protection relays to clear ground faults and localize their positions. However, in the particular case of this 2 × 25 kV system, due to the widespread use of autotransformers, the relation between the distance and the impedance seen by the distance protection relays is not linear and therefore the location is not accurate enough. This paper presents a simple and economical method to identify the subsection between autotransformers and the conductor (catenary or feeder) where the ground fault is happening. This method is based on the comparison of the angle between the current and the voltage of the positive terminal in each autotransformer. Consequently, after the identification of the subsection and the conductor with the ground defect, only the subsection where the ground fault is present will be quickly removed from service, with the minimum effect on rail traffic. This method has been validated through computer simulations and laboratory tests with positive results.

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Section: Experimental Simulationsmentioning

confidence: 99%

A Novel Ground Fault Identification Method for 2 × 5 kV Railway Power Supply Systems

et al. 2015

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“…V s and I s are source vectors and Φ and I L are the potentials of the surface cells and currents through volume cells, respectively. This formulation will be referred to as MNA (Modified Nodal Analysis) formulation later on [15]. By defining a proper time step and using an integration technique, for example the Backward-Euler approximation [16] for its stability [14], for the time derivatives ∂ ∂t , the system of (6), also referred to as Ax = b, can be solved in time.…”

Section: The Peec Methodsmentioning

confidence: 99%

Feasibility analysis of specialized PEEC solvers in comparison to SPICE-like solvers

Safavi

Ekman

2012

J Comput Electron

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The Partial Element Equivalent Circuit (PEEC) method provides an electric equivalent circuit for a physical geometry. This circuit can be combined with external passive/active lumped elements, enabling the simulation and co-design of combined circuit and electromagnetic (EM) structures. The resulted circuit can be solved in a dedicated solver, or equivalently can be exported to a SPICElike solver. In this paper, the inclusion of passive and active lumped circuit elements in PEEC method has been studied and a combined solver has been developed. To demonstrate the capability of the solver, three structures are examined. All examples include a transmission line-PEEC model and active components. Results are compared with those from OrCAD, where an analytical model for the transmission line is used. Good agreement between the results shows the feasibility of using PEEC to solve this type of mixed problems. Also, comparison has been made in terms of implementation and feasibility for the aim of developing the optimal EM solver with active elements support. It is shown that SPICE is not a suitable choice to solve the PEEC models and, a specialized solver can solve the system in a much faster way. On the other hand, all the definitions and models of circuit devices e.g. transistors, MOSFETs, etc. should be implemented in the specialized solver, which raises a tradeoff between the solution time and the implementation time.

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“…The modified nodal circuit analysis method [18] is applied to solve such a circuit using MATLAB (MathWorks Inc.: Natic, MA, USA).…”

Section: Current Distribution In Autotransformers For Different Grounmentioning

confidence: 99%

A New Method of Ground Fault Location in 2 × 25 kV Railway Power Supply Systems

et al. 2017

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Abstract:Owing to the installation of autotransformers at regular intervals along the line, distance protection relays cannot be used with the aim of locating ground faults in 2 × 25 kV railway power supply systems. The reason is that the ratio between impedance and distance to the fault point is not linear in these electrification systems, unlike in 1 × 25 kV power systems. Therefore, the location of ground faults represents a complicated task in 2 × 25 kV railway power supply systems. Various methods have been used to localize the ground fault position in 2 × 25 kV systems. The method described here allows the location of a ground fault to be economically found in an accurate way in real time, using the modules of the circulating currents in different autotransformers when the ground fault occurs. This method first needs to know the subsection and the conductor (catenary or feeder) with the defect, then localizes the ground fault's position.

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Modified nodal analysis: an essential addition to electrical circuit theory and analysis

Cited by 87 publications

References 0 publications

A Novel Ground Fault Identification Method for 2 × 5 kV Railway Power Supply Systems

A Novel Ground Fault Identification Method for 2 × 5 kV Railway Power Supply Systems

Feasibility analysis of specialized PEEC solvers in comparison to SPICE-like solvers

A New Method of Ground Fault Location in 2 × 25 kV Railway Power Supply Systems

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