In order to minimize the losses of the distribution network, solving the reconfiguration problem is a vitally established issue. Modification in the bus connection reduces the system loss and improves the bus voltages...
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ISBN:
(纸本)9781728104072
In order to minimize the losses of the distribution network, solving the reconfiguration problem is a vitally established issue. Modification in the bus connection reduces the system loss and improves the bus voltages as well. Major intricacy for reconfiguring distribution system lies in the development of a convex optimization model constituting voltage-dependent loads. This paper models mixed integer secondorderconic program for Network Reconfiguration of a Distribution System (NRDS), where binary variables depict the branch connections between the buses. A ZIP load model composed of constant impedance, constant current, and constant power type loads, has been deployed for voltage-dependent load study. Proposed ZIP load model based NRDS has been tested on 33-bus, and 69 bus distribution system. Results are compared with the existing model given in literature incorporating only constant power loads that establishes the case for adaptation of the proposed model. Simulated results of constant power and voltage-dependent load model are also validated by performing load flow for evaluated branch connections.
AC Optimal Power Flow (ACOPF) formulation, in general, is nonlinear and non-convex in nature and hence its application to problems like robust system operation, optimal transmission switching, etc. is a herculean task...
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ISBN:
(纸本)9781538661598
AC Optimal Power Flow (ACOPF) formulation, in general, is nonlinear and non-convex in nature and hence its application to problems like robust system operation, optimal transmission switching, etc. is a herculean task. Convexification of OPF is desired in order to reduce the complexity of solving such problems. Existing convex formulations such as Semi-Definite programming (SDP), conventional second order conic programming (SOCP), and so on and their variants result either in significant optimality gap (OG) or reduced OG, albeit with the presence of non-convexity or approximations which bridge the gap between convexity and non-convexity. Due to these challenges, the current practice in the electricity sector is still to use the DCOPF (approximation of ACOPF). Hence in this paper, an exact and novel SOCP formulation of actual ACOPF has been proposed which aims for getting an equivalent convex formulation similar to the actual nonlinear, non-convex ACOPF. This also ensures attaining zero OG for mesh as well as radial networks and hence, the possibility of easily integrating this formulation in OPFs with data uncertainty. The proposed methodology has been tested on a 3 bus, IEEE 14 bus and IEEE 118 bus test systems on GAMS platform. The results thus obtained, have been compared with those obtained from DCOPF, nonlinear, non-convex ACOPF, conventional SOCP formulation for radial networks (SOCP-I) and conventional SOCP formulation for mesh networks (SOCP-II). The results ensure zero OG of the proposed SOCP formulation.
The dissertation research investigates estimating of power system static and dynamic states (e.g. rotor angle, rotor speed, mechanical power, voltage magnitude, voltage phase angle, mechanical reference point) as well...
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The dissertation research investigates estimating of power system static and dynamic states (e.g. rotor angle, rotor speed, mechanical power, voltage magnitude, voltage phase angle, mechanical reference point) as well as identification of synchronous generator parameters. The research has two focuses: i. Synchronous generator dynamic model states and parameters estimation using real-time PMU data. ii. Integrate PMU data and conventional measurements to carry out static state estimation. The first part of the work focuses on Phasor Measurement Unit (PMU) data-based synchronous generator states and parameters estimation. In completed work, PMU data-based synchronous generator model identification is carried out using Unscented Kalman Filter (UKF). The identification not only gives the states and parameters related to a synchronous generator swing dynamics but also gives the states and parameters related to turbine-governor and primary and secondary frequency control. PMU measurements of active power and voltage magnitude, are treated as the inputs to the system while voltage phasor angle, reactive power, and frequency measurements are treated as the outputs. UKF-based estimation can be carried out at real-time. Validation is achieved through event play back to compare the outputs of the simplified simulation model and the PMU measurements, given the same input data. Case studies are conducted not only for measurements collected from a simulation model, but also for a set of real-world PMU data. The research results have been disseminated in one published article. In the second part of the research, new state estimation algorithm is designed for static state estimation. The algorithm contains a new solving strategy together with simultaneous bad data detection. The primary challenge in state estimation solvers relates to the inherent non-linearity and non-convexity of measurement functions which requires using of Interior Point algorithm with no guarantee for a global
Neste trabalho são propostos modelos matemáticos determinístico e estocástico de programação cônica de segunda ordem em coordenadas retangulares para o problema de fluxo de potê...
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Neste trabalho são propostos modelos matemáticos determinístico e estocástico de programação cônica de segunda ordem em coordenadas retangulares para o problema de fluxo de potência ótimo de geração e controle de potência reativa no sistemas elétricos de potência, considerando as minimização dos custos de geração de energia, perdas ativas da rede e emissão de poluentes no meio ambiente. Os modelos contemplam as principais características físicas e econômicas do problema estudado, assim como os limites operacionais do sistema elétrico. Os modelos são programados em linguagem AMPL e suas soluções são obtidas através do solver comercial CPLEX. Os sistemas testes IEEE30, IEEE118 e ACTIVSg200 são utilizados nas simulações computacionais dos modelos propostos. Os resultados obtidos pelo modelo determinístico desenvolvido são validados através de comparações com os resultados fornecidos pelo software MATPOWER , onde ambos consideram apenas a existência de gerações termoelétricas. No modelo estocástico utiliza-se a técnica de geração de cenários e considera-se um período de um ano (8760 horas), e geradores que utilizam fontes de geração renováveis e não renová*** this work we propose deterministic and stochastic mathematical models of secondorderconical programming in rectangular coordinates for the optimal power flow problem of reactive power generation and control in electric power systems, considering the minimization of energy generation costs, losses networks and emission of pollutants into the environment. The models contemplate the main physical and economic characteristics of the studied problem, as well as the operational limits of the electric system. The models are programmed in AMPL language and their solutions are obtained through the commercial solver CPLEX. The IEEE30, IEEE118 and ACTIVSg200 test systems are used in the computer simulations of the proposed models. The results obtained by the deterministic model developed are validated through comparison
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