To Analytical Evaluation Of Symmetrizating Capacitors
System approach to the problem of analytical evaluation of capacitors, which are symmetrizating currents in three-phase system of power supply with the asymmetrical active-inductive load is offered in the article. Sources of electric energy are supposed absolutely symmetrical and to have infinite power supply. The parameters of the asymmetrical mode were found with the package of software MATHCAD. This package was chosen because of ability to execute operations with complex variables. Graph method was appealed to form the system of mathematical equations of power-supply system for computer model. This equations ware written in complex form for all main loops of oriented graph of power-supply system. To solve the system of the equations was used method of searching optimization in MATHCAD with operator “given-find”. This information allowed estimating the current of negative phase-sequence which must be balanced for achievement of the symmetric mode. Amplitudes of currents of balance capacitors and values of their capacitances were calculated. In method which is known to calculate parameters of simmetrizating elements they used geometrical calculations. Calculating formulas are depended on location of the negative phase-sequence current vector. Proposed method allowed to calculate this parameters without geometrical solving. For the purpose MATHCAD operator “given-find” was used too. Then the parameters of the symmetrical mode wеre found with the package of software MATHCAD to test results of symmetrization. The computer experience has shown that such method does not provide an exact symmetrization. The linear currents are different yet because a number of factors were not taken into account here. In particular reactive power of transmission line are not were disregarded. The method of searching optimization calculates exact result and provides complete compensation of reactive power in all system and its work in the optimal condition with minimum of loss. The transmission line currents are absolutely equal and minimal in this case.