Loss minimization in the modified algorithm of load flow analysis in industrial power system

摘要

The research looks at an alternative technique of loss minimization using B-lossformula in solving load flow analysis. A modeling of electrical system elements is firstdeveloped. A literature review on the history and development of load flow analysisand loss minimization especially on the use of B-loss formula are delivered. A reporton load flow in practice and loss minimization measures based on a utility visit toEnergyAustralia is given. An analysis on three types of industrial power systems is alsodiscussed. A substantial study on EDSA was made to adapt the commercial load flowprogram and demonstrate voltage control methods to achieve loss minimization.The research thesis work focuses on the use of a load flow analysis program to calculateand minimize losses in large electrical power distribution system such as an industrialpower system. A Matlab load flow analysis program has been developed successfullyusing modified polar Newton-Raphson algorithms based on bus admittance matrix Ybusand the use of B-loss coefficient method. Real power losses are calculated using Blossescoefficients for achieving loss minimization and the technique has been verifiedwith the traditional I2R and/or differential power methods. Modified load flowalgorithm is also implemented by applying voltage control methods using either a shuntcapacitor or a load tap changing (LTC) transformer. Voltage level is improved whilstminimizing losses. Appropriate modeling of a capacitor and an LTC transformer havebeen developed proven. A network of a typical meshed secondary selective system offive bus has been chosen and used as the test case. Several case studies with differentvalues of capacitance and tap settings of transformer have been conducted to determineminimum losses. Further sensitivity analysis is carried out by simulating a wide rangeof load power configurations and line and transformer resistances to verify therobustness of the proposed modified algorithms especially on the use of B-lossesalgorithm for the chosen network. Results showed that the proposed algorithms,although less accurate than full I2R calculations, are robust and reliable to achieve lossminimization for various ranges of load and impedance configurations. There isconfidence in applying the method to larger systems.This two-year thesis details novel contribution towards loss minimization in powersystems by applying B-losses formula into a load flow program, expressing the systemlosses in terms of active power generations which allows coordination of transmissionlosses in scheduling output of each generating plant. This gives maximum economy fora given load and achieves loss minimization using voltage control methods. Thistechnique is not possible using standard commercial load flow programs.