Sebuah model sistem kuasa elektrik di dalam analisis aliran kuasa terdiri daripada bus
dalam sistem, unit penjanaan dan elemen beban yang menghubungkan setiap bus dan
penghantaran setiap bus. Keputusan yang penting dalam analisa ialah mengenalpasti
magnitud voltan dan sudut fasa setiap bus. Maka daripada maklumat yang diketahui ini,
kita boleh mengenalpasti aliran arus, kuasa sebenar dan kuasa reaktif. Selain itu sesuatu
sistem memerlukan perancangan operasi, ekonomi adan penukaran tenaga kepada
pengguna. Teknik biasa yang selalu digunakan adalah kaedah Newton-Raphson, Gauss-
Seidel dan Quasi-Newton. Newton-Raphson adalah kaedah matematik yang lebih
berkesan berbanding kaedah Gauss-Seidel. Untuk sistem kuasa yang lebih besar, kaedah
Newton-Raphson adalah lebih berkesan dan praktikal. Bilangan iteratif yang diperlukan
dalam penyelesaian adalah bergantung kepada saiz sesuatu sistem. Projek ini
menunjukkan kaedah Newton-Raphson untuk aliran kuasa. Keputusan IEEE-5 bus sistem
digunakan untuk perbandingan. Perisian MATLAB digunakan untuk simulasi.
Perbandingan keputusan Hadi Saadat ditunjukkan pada bab 4.
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The model of the electric power system that is used in a power flow analysis consist of
all the busses in the system, the generating units and load elements connected to these
various buses, and the transmission lines that interconnected the buses. The information
furnished by a power flow analysis is quite simply the voltage profile of the system. In
other words, the important result of the analysis is the determination of the voltage
magnitude and its associated phase angle at each bus. Of course, once this information is
known, it is a routine matter to determine the currents in each transmission link, and
accordingly, the real and reactive power flows. Conclusions regarding overloads on any
of the system components are obtained at this point in the study. They are necessary for
planning operation, economic scheduling and exchange of power between utilities. In
addition, power flow analysis is required for many other analyses such as transient
stability and contingency studies. The most common techniques used for the iterative
solution of nonlinear algebraic equations are Gauss-Seidel, Newton –Raphson, and
Quasi-Newton methods. Because of its quadratic convergence, Newton’s method is
mathematically superior to the Gauss-Seidel method and is less prone to divergence with
ill-conditioned problems. For large power systems, the Newton- Raphson method is
found to be more efficient and practical. The number of iterations required to obtain the
solution is independent of the system size, but more functional evaluations are required at
each iteration. This project presents Newton-Raphson method for conducting load flow.
A practical IEEE-5 bus system is considered for illustrator. A software in MATLAB is
written and load flow is simulated. The results are compared with the programs written
by Hadi Saadat and presented in the Chapter 4.