Research On Parameter Identification System Of Linear Low Resistance Network

Linear resistive network is applied widely, and is the basic of ensuring powerelectronic equipments’ reliable operation. The most important evaluating parameterof working performance is network resistance. Because the parallel connectionrelationship between branches is quite complex, traditional measuring instrumentcan’t obtain resistances by online testing.When resistances are low is more difficult.According to practical needs of testing on electronic modules and stereo groundnetwork, this paper studies on the identification technique of linear low resistancenetwork parameter and constructs general hardware-software automatic test system.This paper firstly proposes a linear network circuit new model based onnetwork graph theory which is suitable for the least squares standard form, describesits characteristics and key relationships between physical quantities through matrix,and develops parameter estimation algorithm based on the recursive way whichcould effectively avoid the general inverse matrix difficult process under noiseenvironment. Based on this, it puts forward two steps to solve black box structureand network testing respectively and according to the identification and testingprinciple, it proposes a complete structure of linear low resistance networkparameter identification and testing system. Secondly, this paper gives a detailedexplanation of the software program and hardware circuit device. The softwaremeets the requirements of both system simulation and online measurement andpossesses all of the functions of network parameters identification. It integrates thecore algorithm functions based on the strict layered modularized principle, andprovides users with friendly human-computer interaction interface; Meanwhile, thenecessary hardware circuit uses modularized structure, respectively designs theembedded microcontroller control module supporting data communication withUSB, large current and low contact potential relay modules based on bus control,and a feasible stimulated current source and an external data acquisition interface.All the hardware circuit modules are installed in the same metal box and have theadvantages of compact structure, reliable performance and simple process.Finally, in order to verify effectiveness and practicability of the new methodand the new structure equipment, this paper takes stereo ground network resistancetesting project as example, constructs the portable stereo ground network simulationdevice and uses it to explain the operation method and testing process. Theexperimental results and error analysis shows that the system is reliable, easy tooperate and it could meet the precision requirements in a wide range.