Papers by Vander Da Costa
International Journal of Electrical Power & Energy Systems, 2005
ABSTRACT This paper presents a new second order power flow methodology by using current injection... more ABSTRACT This paper presents a new second order power flow methodology by using current injection equations expressed in voltage rectangular coordinates instead of using traditional rectangular power flow equations. The results presented show that the proposed method leads to a substantially faster second order power flow solution, when compared to the conventional method expressed in terms of power mismatches and written in rectangular coordinates. In order to evaluate the performance of the proposed methodology, different heavily loaded and overloaded systems, as well as ill-conditioned distribution systems have been tested. These results show the feasibility of employing this new methodology as an additional tool for power flow studies.
International Journal of Electrical Power & Energy Systems, 2007
This paper presents a new step size optimization factor to be used for solving unbalanced three-p... more This paper presents a new step size optimization factor to be used for solving unbalanced three-phase distribution current injection power flow. This optimization factor improves the performance of the iterative process namely at higher loading level and R/X ratio. In addition, this ...
Sba: Controle & Automação Sociedade Brasileira de Automatica, 2003
International Journal of Electrical Power and Energy Systems, 2001
ABSTRACT
International Journal of Electrical Power and Energy System, 2003
This paper describes a sparse ð4n £ 4nÞ formulation for the solution of power flow problem, compr... more This paper describes a sparse ð4n £ 4nÞ formulation for the solution of power flow problem, comprising 2n current injection equations written in rectangular coordinates plus the set of control equations. This formulation has the same convergence characteristics of the conventional Newton power flow problem, expressed in terms of power mismatches written in polar coordinates and can be reduced to a ð2n £ 2nÞ formulation plus the control equations. It is best suited to the incorporation of flexible AC transmission system devices and controls of any kind. Complex user-defined control functions, involving the participation of several regulating devices, can be directly introduced as power flow control data. The results presented validate the proposed method. q
International Journal of Electrical Power & Energy Systems, 2010
This paper presents new mathematical models to compute the loading margin, as well as to perform ... more This paper presents new mathematical models to compute the loading margin, as well as to perform the sensitivity analysis of loading margin with respect to different electric system parameters. The innovative idea consists of evaluating the performance of these methods when the ...
IEEE Transactions on Power Systems, 2000
The original paper (“Three-phase power flow calculations using the current injection method” by P... more The original paper (“Three-phase power flow calculations using the current injection method” by P.A.N. Garcia et al., see ibid., vol.15, no.2, p.508-14, 2000) is discussed by the authors. The original authors' reply is also included
IEEE Transactions on Power Systems, 1999
... IEE Proceedings, 118, No. 8:983-987, August 1971. 131 B. Stott. ... Biographies Vander M. Cos... more ... IEE Proceedings, 118, No. 8:983-987, August 1971. 131 B. Stott. ... Biographies Vander M. Costa received his B.Sc.(1980) from the Fed-eral University of Juiz de Fora, Brazil. He received his MSc.(1983) from COPPFI Federal Univcrsity of Rio de Jmeiro, Brazil. ...
This paper presents a new sparse formulation for the solution of unbalanced three-phase power sys... more This paper presents a new sparse formulation for the solution of unbalanced three-phase power systems using the Newton-Raphson method. The three-phase current injection equations are written in rectangular coordinates resulting in an order 6 system of equations. The Jacobian matrix is composed of 6 6 block matrices and retains the same structure as the nodal admittance matrix. Practical distribution systems were used to test the method and to compare its robustness with that of the backward/forward sweep method.
Proceedings of The IEEE, 2000
This paper describes a power flow program which has been utilized by Brazilian utilities over the... more This paper describes a power flow program which has been utilized by Brazilian utilities over the last 20 years, and is now being re-engineered to accommodate the full Newton-Raphson modeling of FACTS devices, LTC transformers, HVDC links, voltage stability analysis, remote voltage control and secondary voltage control. An augmented system of equations is required to represent a device control action and its corresponding control variable. Results on practical test systems are introduced to demonstrate the numerical robustness of the proposed approach.
IEEE Transactions on Power Systems, 2000
Advanced load flow models for the static VAR cumpensator (SVC) are presented in this paper. The m... more Advanced load flow models for the static VAR cumpensator (SVC) are presented in this paper. The models are incorporated into existing load flow (LF) and optimal power flow (OPF) Newton algorithms. Unlike SVC models available in open literature, the new models depart from the generator representation of the SVC and are based instead on the variable shunt susceptance concept. In particular, a SVC model which uses the firing angle as the state variable provides key information for cases when the load flow solution is used to initialize other power system appliedtions, e.g., harmonic analysis. The SVC state variables are combined with the nodal voltage magnitudes and angles of the network in a single frame-of-reference fur U unified, iterative solution through Newton methods. Both algorithms, the LF and the OPF exhibit very strong convergence characteristics, regardless of network size and the number of controllable devices. Results are presented which demonstrate the prowess of the new SVC models.
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Papers by Vander Da Costa