To satisfy the requirement of developing a new generation of motorized treadmill for a famous domestic manufacturer, a brushless DC motor （BLDCM） driving and control system for motorized treadmill is developed. High...To satisfy the requirement of developing a new generation of motorized treadmill for a famous domestic manufacturer, a brushless DC motor （BLDCM） driving and control system for motorized treadmill is developed. High integration and reliability of this system are ensured under the condition that intelligent power module （IPM） is used and the protection module is included. Periodic current control method is applied to reduce the average current flowing through the armature winding of the motor when the treadmill is required to start with low speed while large load is added. Piecewise proportion-integration-differentiation （PID） control algorithm is applied to solve the problem of speed fluctuation when impulse load is added. The motorized treadmill of a new generation with the driving and control system has the advantages of high reliability, good speed stability, wide timing scope, low cost, and long life-span. And it is very promising for practical applications.展开更多
对油纸绝缘样品施加10 k V/mm场强进行电老化试验,并采用松弛电流法研究了油纸绝缘的老化评估方法。利用色谱法测试不同老化程度油样中的溶解气体,发现老化前后气体含量变化显著,说明经电老化的试样老化明显。分别选取6个老化时间点的...对油纸绝缘样品施加10 k V/mm场强进行电老化试验,并采用松弛电流法研究了油纸绝缘的老化评估方法。利用色谱法测试不同老化程度油样中的溶解气体,发现老化前后气体含量变化显著,说明经电老化的试样老化明显。分别选取6个老化时间点的样品进行松弛电流测试,从不同角度分析不同参量所表征的老化信息。利用I*t^log10t曲线分析了油纸试样的陷阱分布,发现试样老化初期陷阱密度逐渐增加,试样老化后期陷阱深度明显加深。运用四阶Debye模型对电流曲线进行拟合,推断了油纸绝缘四种松弛机制的物理机理,发现各松弛机制随着老化时间的增加有不同程度的增大。最后研究了去极化电量随老化时间的变化趋势,试图用直观参数分析试样在不同时间点的老化程度,发现在60 h后开始大幅度加深。展开更多
文摘To satisfy the requirement of developing a new generation of motorized treadmill for a famous domestic manufacturer, a brushless DC motor （BLDCM） driving and control system for motorized treadmill is developed. High integration and reliability of this system are ensured under the condition that intelligent power module （IPM） is used and the protection module is included. Periodic current control method is applied to reduce the average current flowing through the armature winding of the motor when the treadmill is required to start with low speed while large load is added. Piecewise proportion-integration-differentiation （PID） control algorithm is applied to solve the problem of speed fluctuation when impulse load is added. The motorized treadmill of a new generation with the driving and control system has the advantages of high reliability, good speed stability, wide timing scope, low cost, and long life-span. And it is very promising for practical applications.
文摘对油纸绝缘样品施加10 k V/mm场强进行电老化试验,并采用松弛电流法研究了油纸绝缘的老化评估方法。利用色谱法测试不同老化程度油样中的溶解气体,发现老化前后气体含量变化显著,说明经电老化的试样老化明显。分别选取6个老化时间点的样品进行松弛电流测试,从不同角度分析不同参量所表征的老化信息。利用I*t^log10t曲线分析了油纸试样的陷阱分布,发现试样老化初期陷阱密度逐渐增加,试样老化后期陷阱深度明显加深。运用四阶Debye模型对电流曲线进行拟合,推断了油纸绝缘四种松弛机制的物理机理,发现各松弛机制随着老化时间的增加有不同程度的增大。最后研究了去极化电量随老化时间的变化趋势,试图用直观参数分析试样在不同时间点的老化程度,发现在60 h后开始大幅度加深。
