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基于基波分析方法的绕组电流谐波计算研究 被引量:6
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作者 姚生奎 陈明 +1 位作者 李成 梁旭 《智慧电力》 北大核心 2021年第8期91-97,共7页
三相双有源桥DC-DC变换器的固有软开关能力、滤波电容器电流低等特点而广泛应用于直流配电网。基于三相双向有源桥DC-DC变换器的拓扑结构,分析了不同联接方式下的高频三相变压器的电压电流波形。基于变压器在三种不同联接方式下的近似... 三相双有源桥DC-DC变换器的固有软开关能力、滤波电容器电流低等特点而广泛应用于直流配电网。基于三相双向有源桥DC-DC变换器的拓扑结构,分析了不同联接方式下的高频三相变压器的电压电流波形。基于变压器在三种不同联接方式下的近似等效电路模型和电压与电流之间的相量图,采用基波分析方法推导了高频三相变压器绕组电流的各阶次谐波计算表达式,结合各阶次谐波频率下的交流电阻系数表达式,进而实现绕组高频损耗的计算。最后,将解析计算结果与仿真结果进行对比,结果表明各阶次谐波电流幅值、绕组总损耗值与解析计算方法的最大误差为8.4%,验证了解析计算方法的正确性。 展开更多
关键词 三相双有源桥 基波分析方法 谐波计算表达式 绕组损耗
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Short-term forecasting optimization algorithms for wind speed along Qinghai-Tibet railway based on different intelligent modeling theories 被引量:8
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作者 刘辉 田红旗 李燕飞 《Journal of Central South University》 SCIE EI CAS 2009年第4期690-696,共7页
To protect trains against strong cross-wind along Qinghai-Tibet railway, a strong wind speed monitoring and warning system was developed. And to obtain high-precision wind speed short-term forecasting values for the s... To protect trains against strong cross-wind along Qinghai-Tibet railway, a strong wind speed monitoring and warning system was developed. And to obtain high-precision wind speed short-term forecasting values for the system to make more accurate scheduling decision, two optimization algorithms were proposed. Using them to make calculative examples for actual wind speed time series from the 18th meteorological station, the results show that: the optimization algorithm based on wavelet analysis method and improved time series analysis method can attain high-precision multi-step forecasting values, the mean relative errors of one-step, three-step, five-step and ten-step forecasting are only 0.30%, 0.75%, 1.15% and 1.65%, respectively. The optimization algorithm based on wavelet analysis method and Kalman time series analysis method can obtain high-precision one-step forecasting values, the mean relative error of one-step forecasting is reduced by 61.67% to 0.115%. The two optimization algorithms both maintain the modeling simple character, and can attain prediction explicit equations after modeling calculation. 展开更多
关键词 train safety wind speed forecasting wavelet analysis time series analysis Kalman filter optimization algorithm
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