Approach And Equipment To Determine The Steady-state Equivalent Circuit Parameters Of Three-phase Induction Motors

Induction motors are applied to production and automation processes extensively because they have the merits of small size, light weight, low cost, high efficiency, reliable function and convenient maintenance. It is important for either design, manufacture and evaluation or application and maintenance of motors to determine the steady-state equivalent circuit parameters of induction motors precisely and conveniently.The steady-state equivalent circuit parameters of induction motors could be calculated during the process of designing, but commonly, they are determined through test after motors are manufactured. This paper quotes three methods for determining the steady-state equivalent circuit parameters of three-phase induction motors: the classical locked-rotor and non-load tests, the direct parameter modification and the recursive least-squares method;The introduction also analyzed advantages and disadvantages of these methods, and then presents genetic algorithms based determination methods for steady-state equivalent circuit parameters of induction motors.At the first, based on the steady-state equivalent circuit model and the characteristic functions of induction motors, this paper elaborates on the principle and realization of genetic algorithms.And then, analyzes the combination of genetic algorithms and induction motors, discusses the characteristics of genetic algorithms of my design and presents the simulation characteristic versus slip curves by using oriented and visualized C++ builder 6.0. Based on simulation, We design a system for the realization of parameter determination of induction motors, which includes hardware design and software design. Additionally, the relevant hardware design, software flow chart and main interfaces are presented.Finally, applies this approach and equivalent to the parameter determination of a three-phase induction motor. We use the method ofclassical parameter determination and the method presented in this paper respectively to obtain the steady-state equivalent circuit parameters;then, basing on the relevant data from testing, we obtain the characteristic versus slip curves by using least-squares method. And then, by comparing the results from classical parameter test method, we conclude that my method improves the precision of parameter determination remarkably, and therefore my method proves to be feasible and valid.