Hardware Design Of Steady-state Equivalent Circuit Parameters Identification System 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.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. Basing on the relevant data of current and speed of motor from testing and steady-state equivalent circuit equation of induction motors, we obtain the parameters of induction motors and characteristic versus slip curves by using least-squares method.The hardware and software's design scheme of the parameters identification of a three-phase induction motor is based on high performance digital signal processor TMS320LF2407A.The function blocks of data sampling and processing system are particularly described and the circuit configurations are given. A detailed description about DSP assembler language program design characteristic and methods are introduced. The hardware system is realized by DSP assembler language, including the velocity detection of motor, the current collection and processing, serial Communication and so on. This scheme makes the system design simpler, the performance more optimized, the reliability more high.Finally, applies this approach and equivalent to the parameters identification of a three-phase induction motor. By comparing the parameters of induction motors and characteristic versus slip curves of the system to classical parameter test method's, we conclude that my method improves the precision of parameters identification remarkably, and therefore my method proves to be feasible and valid.