Study On Fuzzy Reliability And Fuzzy Robust Design Technology For Intelligent Moulded Case Circuit Breaker Operating Mechanism Based On Virtual Prototyping

The low-voltage intelligent MCCB is a key appliance in intelligent distributionnetwork，its reliability directly affects the safe and reliable operation of the low-voltageintelligent power grid. The operating mechanism is a core component of an intelligentMCCB. In this pape, the operating mechanism of an intelligent MCCB was selected as theobject of study. The optimization design method by combining virtual prototype and fuzzyreliability and fuzzy robust techniques has been studied.The modeling method of the intelligent MCCB operating mechanism virtual prototyperigid models, parametric models and flexible models has been introduced in this paper. Theplanar three-point circle center positioning method, based on machine vision technology,was proposed for the problem that the irregular-shaped shaft test hole for mechanicalcharacteristics of the intelligent MCCB is difficult to position and machine. The intelligentMCCB mechanical properties test platform was builded. The intelligent MCCB operatingmechanism virtual prototype model effectiveness has been proved.The spring optimization method by combining virtual prototype and fuzzy reliabilitytechniques was presented. First, the use of the operating mechanism virtual prototypemodel optimized the spring stiffness coefficient. Then, the spring fuzzy reliabilityoptimization model was established to optimize the structural parameters of the spring,which used the lightest spring mass as the objective function.Considering the intelligent MCCB operating mechanism two motion laws of manualopening and trip-free, and the influence of various fuzzy factors in the process of designand manufacture on main shaft motion accuracy, the optimization design method thatvirtual prototype technique combining with multi-objective fuzzy robust design theory hasbeen presented for optimizing the intelligent MCCB operating mechanism. And then usedof ADAMS/Insight Monte Carlo method analyzed the optimal results.The studies have shown that the intelligent MCCB operating mechanism designed bycombining prototype and fuzzy reliability and fuzzy robust techniques has small size, highbreaking capacity, and high reliability and robustness, which is consistent with theintelligent MCCB development trend.