排序方式: 共有101条查询结果,搜索用时 562 毫秒
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基于PLC的万能式断路器大电流检测系统实现 总被引:1,自引:0,他引:1
以PLC、工业控制计算机、传感器为核心,自动电流调节检测、自动装夹的断路器三相大电流自动化检测系统替代原有的断路器过流保护功能的手工和单相检测方式,保证了过流保护功能测试精度,减少了人为误差,同时极大地提高了生产效率。 相似文献
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线路和设备的欠电压与保护 总被引:2,自引:0,他引:2
论述了线路和设备在欠电压(电压不足)情况下运行的危害和电动机在临界电压下产生的疲倒、堵转,同时介绍了欠电压保护设备的结构、工作原理、动作值和动作时间的选择等。 相似文献
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提出了塑壳式断路器用电流互感器(CT)的软件修正方法.分析了小电流、无畸变和大电流时的CT波形,编写了Matlab程序对CT的特性曲线进行拟合,并给出了实测和拟合的曲线.修正结果表明,该方法精度和可靠性高,在实际应用中简化了设计. 相似文献
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Based on the solid-liquid two-phase mixture transportation test, the renormalization group (RNG) k-e turbulent model was utilized to simulate the solid-liquid two-phase turbulent flow in a centrifugal pump. By comparing the simulated and experimental results, inner flow features were revealed to improve the abrasion characteristic of the solid-liquid two-phase centrifugal pump. The influence of the solid phase on centrifugal pump abrasive performance is small when the particle volume fraction is less than 2.5%. The aggregation degree of the solid particles is enhanced as the particle diameter increases from 0.1 to 1 mm; however, the mixture density on the pressure side is reduced when the particle diameter increases to 1 mm for the impact of inertia. The wear on the hub is most severe for the shear stress on this position; it is also the largest. The wear characteristic is affected greatly by the parameters of the solid phase. The wear chracteristic can be optimized by decreasing the blade outlet angle. In the modified design, the blade angle is different, whereas the other geometric dimensions remain the same. The improved pump is simulated to contrast with the original pump. The results show that the values of mixture density and shear stress both decrease. The wear condition of the blade is improved to a certain extent. 相似文献
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解析Modbus-RTU协议关键内容及其在智能电器中的应用 总被引:2,自引:0,他引:2
Modbus是一种广泛应用于工业控制领域的标准通信协议,它包括两种通信模式:ASCII模式和RTU(远程终端单元)模式。对Modbus—RTU协议中的关键内容进行了较全面的解析,并介绍了一些设计从站节点时的思路,以及在智能电器中的具体应用。 相似文献