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电网对称故障时双馈感应发电机低电压穿越控制 总被引:3,自引:1,他引:3
分析电网对称故障时,双馈感应风力发电机定子磁链变化过程、导致定转子过电流的原因、电网故障发生具体时刻及故障程度对双馈感应发电机定转子的影响,提出一种双馈感应风力发电机转子侧变换器低电压穿越控制策略,改善了双馈感应发电机在电网故障时定、转子过电流的情况,实现了双馈感应发电机在电网对称故障时的低电压穿越.在理论分析基础上,建立双馈感应发电机转子侧变换器低电压穿越控制模型和3 kW双馈感应发电机励磁变换器低电压穿越控制实验系统.实验结果表明,所提出的双馈感应发电机低电压穿越控制策略动态响应快、方法行之有效. 相似文献
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Additives and iodine(I2) are used to modify the binary room temperature ionic liquid(RTIL) electrolyte to enhance the photovoltaic performance of dye-sensitized solar cells(DSSCs). The short-circuit current density(JSC) of 17.89 m A/ cm2, open circuit voltage(VOC) of 0.71 V and fill factor(FF) of 0.50 are achieved in the optimal device. An average photoelectric conversion efficiency(PCE) of 6.35% is achieved by optimization, which is over two times larger than that of the parent device before optimization(2.06%), while the maximum PCE can reach up to 6.63%. 相似文献
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以黑曲霉(Aspergillus niger)Y8为研究对象,经过紫外-高温复合诱变处理后,利用初筛及复筛,得到一株耐高温高产葡萄糖酸盐的黑曲霉菌株UT-1。菌株UT-1在45 ℃,220 r/min条件下进行摇瓶发酵,其平均产葡萄糖酸盐的量为(23.23±0.02) g/100 mL,较出发菌株提高了32.44%,经4次传代培养后,菌株UT-1遗传稳定性能良好。5 L发酵罐试验结果表明,菌株UT-1与出发菌株相比适应期缩短了2 h,发酵周期缩短了4 h,葡萄糖酸盐产量提高了17.14%,为葡萄糖酸盐工业化生产提供理论基础和技术支持。 相似文献
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The photovoltaic performance of dye-sensitized solar cells (DSSCs) is enhanced by modifying the binary room temperature ionic liquid (RTIL) electrolyte with additives and iodine. The average photoelectric conversion efficiency (PCE) of 6.39% is achieved. Through electrochemical impedance spectroscopy (EIS), cyclic voltammetry scans and incident photon-to-current conversion efficiency (IPCE) data, the working principles are analyzed. The enhancement is mainly attributed to the improvement of short circuit current which is caused by the reduction of overall internal resistance of the devices. Durability tests are measured at room temperature, and the long-term stability performance can be maintained. This work has been supported by the National Natural Science Foundation of China (No.61474064). E-mail:zcliang@njupt.edu.cn 相似文献
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基于静态补偿电压模型磁链观测器的矢量控制系统在电机运行于低速时,稳定性不佳,负载能力不足。从静态补偿电压模型原理出发,深入分析了磁链静态补偿原理,并结合感应电机模型得出基于静态补偿电压模型的矢量控制系统磁链非线性动态方程。同时利用李雅普诺夫线性化理论,对非线性磁链系统进行局部线性化建立起磁链线性化模型,通过分析线性化系统的稳定性,给出了一种判别磁链非线性系统在平衡点处稳定性的方法。从理论上分析和证明了基于静态补偿电压模型磁链观测的感应电机矢量控制系统分别在高、低速运行时的稳定性。对理论分析给出了仿真和实验验证。 相似文献
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