The systematic mathematical analysis of the high frequency soft-switched AC-AC converter is proposed for variable frequency induction machine load in this paper. Both PWM and square-wave modes of operation have been c...The systematic mathematical analysis of the high frequency soft-switched AC-AC converter is proposed for variable frequency induction machine load in this paper. Both PWM and square-wave modes of operation have been considered. The frequency relation and phase unbalance problem due to discrete time integral half-cycle switching has been discussed in the beginning. Then, generalized Fourier series have been derived for output voltage, output current and supply current in two modes.The analytical results help to understand tbe converter characteristics, design optimally a convertermachine system of arbitrary capacity considering the various trade-off parameters.展开更多
Digital receivers have become more and more popular in radar, communication, and electric warfare for the advantages compared with their analog counterparts. But conventional digital receivers have been generally cons...Digital receivers have become more and more popular in radar, communication, and electric warfare for the advantages compared with their analog counterparts. But conventional digital receivers have been generally considered impractical for bandwidth greater than several hundreds MHz. To extend receiver bandwidth, decrease data rate and save hardware resources, three novel structures are proposed. They decimate the data stream prior to mixing and filtering, then process the multiple decimated streams in parallel at a lower rate. Consequently it is feasible to realize wideband receivers on the current ASIC devices. A design example and corresponding simulation results are demonstrated to evaluate the proposed structures.展开更多
基于TEAM Problem 21基准族选取换流变压器常用的导磁钢板、硅钢叠片和铜板材料,在50~2450 Hz频率范围内,进行了3种材料杂散损耗随频率变化的测量,并基于标准方法,分析了3种材料杂散损耗与谐波次数指数的对应关系。研究结果表明:随着频...基于TEAM Problem 21基准族选取换流变压器常用的导磁钢板、硅钢叠片和铜板材料,在50~2450 Hz频率范围内,进行了3种材料杂散损耗随频率变化的测量,并基于标准方法,分析了3种材料杂散损耗与谐波次数指数的对应关系。研究结果表明:随着频率增加,结构件损耗均呈增加趋势;导磁钢板和硅钢叠片的杂散损耗指数大于标准推荐值,铜板的杂散损耗指数小于标准推荐值。展开更多
文摘The systematic mathematical analysis of the high frequency soft-switched AC-AC converter is proposed for variable frequency induction machine load in this paper. Both PWM and square-wave modes of operation have been considered. The frequency relation and phase unbalance problem due to discrete time integral half-cycle switching has been discussed in the beginning. Then, generalized Fourier series have been derived for output voltage, output current and supply current in two modes.The analytical results help to understand tbe converter characteristics, design optimally a convertermachine system of arbitrary capacity considering the various trade-off parameters.
基金This project was supported by the National Defense I mportant Research Foundation of China(03413070506)
文摘Digital receivers have become more and more popular in radar, communication, and electric warfare for the advantages compared with their analog counterparts. But conventional digital receivers have been generally considered impractical for bandwidth greater than several hundreds MHz. To extend receiver bandwidth, decrease data rate and save hardware resources, three novel structures are proposed. They decimate the data stream prior to mixing and filtering, then process the multiple decimated streams in parallel at a lower rate. Consequently it is feasible to realize wideband receivers on the current ASIC devices. A design example and corresponding simulation results are demonstrated to evaluate the proposed structures.
文摘基于TEAM Problem 21基准族选取换流变压器常用的导磁钢板、硅钢叠片和铜板材料,在50~2450 Hz频率范围内,进行了3种材料杂散损耗随频率变化的测量,并基于标准方法,分析了3种材料杂散损耗与谐波次数指数的对应关系。研究结果表明:随着频率增加,结构件损耗均呈增加趋势;导磁钢板和硅钢叠片的杂散损耗指数大于标准推荐值,铜板的杂散损耗指数小于标准推荐值。
