Study On Static And Dynamic Characteristics Test System For Intrinsically Safe Electromagnet

The electro-hydraulic control technology of the support is a keytechnology of the fully mechanized mining equipments. The electro-hydrauliccontrol valve group is the core of the support electro-hydraulic control system.The Electromagnet failure will lead to solenoid valve failure, which will affectthe safe production in the fully mechanized working face. On the other hand,the performance of hydraulic support control system will determine theefficiency of coal mine production. And the intrinsically safe electromagnet iskey components of the hydraulic control system. Thus the experimentalinvestigation of the dynamic and static characteristics study for intrinsicallysafe electromagnet is the only way to improve the reliability and efficiency. Atpresent, this type electromagnet testing system has not been designed indomestic. In order to improve the design and manufacture level of of theintrinsically safe electromagnet, innovating a set of the characteristics testsystem is very necessary.Firstly,in order to certain the testing system parameters, the subsection magnetic circuit method was adopted in this article firstly for modeling andsimulating the intrinsically safe electromagnet. The electromagnetdisplacement and current simulation curves of the dynamic characteristicswere carried out. And the current frequency characteristic was calculated bythe power spectrum method, which provide a reference for the selection of thesensor.The test system whose hardware foundation was based on the NIPXI-8108host was putted forward set the LabVIEW software as the testingsoft was development environment.The test system adopts AC servo motorconsole as loading device for accepting instruction from PXI-7344movementcontrol card.In order to match with the intrinsically safe electromagnet features, theparallel beam resilience sensor, the electric eddy current displacement sensorand the hall current sensor were used. The force sensor and displacementsensor mechanical installation structure were designed, which not only theinstallation error influence on measurement accuracy was considered, thecorresponding structures have been designed that can provide logic protectelectric signals for control unit.Because of the force sensor deformation during the testing process ofstatic characteristics, this paper presented a compensation strategy tocompensate for the force sensor deformation based on the dichotomy. Inposition servo state, the servo system disturbance problems will influence the force sensor in the process of measuring. In this paper, the notch filterstechnology was brought out to reducing the signal oscillation of the forceduring the loading process.For testing the dynamic characteristics of intrinsically safe electromagnet,the method for testing transient response of the armature displacement and thecurrent were putted out. In order to reduce the measurement inaccuracy by theload effect, the eddy current sensor probe structure was designed reasonably.And also, the error of current test was analyzed.This system, which has been proven accuracy, convenient in practice, hasreached the design purpose.The subject is sponsored by research and development of hydraulicsupport electro-hydraulic control valves,shanxi province major science andtechnology research projects(Grant NO.20111101025).