A soft switching three-transistor push-pull(TTPP)converter is proposed in this paper. The 3rd transistor is inserted in the primary side of a traditional push-pull converter. Two primitive transistors can achieve zero...A soft switching three-transistor push-pull(TTPP)converter is proposed in this paper. The 3rd transistor is inserted in the primary side of a traditional push-pull converter. Two primitive transistors can achieve zero-voltage-switching (ZVS) easily under a wide load range, the 3rd transistor can also realize zero-voltage-switching assisted by leakage inductance. The rated voltage of the 3rd transistor is half of that of the main transistors. The operation theory is explained in detail. The soft-switching realization conditions are derived. An 800 W with 83.3 kHz switching frequency prototype has been built. The experimental result is provided to verify the analysis.展开更多
超高压(extra high voltage,EHV)同塔三回线路复杂的电磁耦合给其零序参数的精确测量带来极大的挑战。该文总结了现有的零序参数测量方法,分析了各测量方法的优缺点。在此基础上提出了一种基于双端同步测量的EHV同塔三回线路零序参数的...超高压(extra high voltage,EHV)同塔三回线路复杂的电磁耦合给其零序参数的精确测量带来极大的挑战。该文总结了现有的零序参数测量方法,分析了各测量方法的优缺点。在此基础上提出了一种基于双端同步测量的EHV同塔三回线路零序参数的精确测量方法。建立了长距离EHV同塔三回线路的分布参数模型,推导了利用双端同步测量信息的同塔三回线路传输线方程的求解公式,给出了同塔三回线路的测量接线方式和零序参数的测量步骤,利用PSCAD/EMTDC验证了所提测量方法的准确性,并与传统测量方法进行了对比。仿真结果表明:传统方法测量精度低,改进的传统方法能提高短距离输电线路的测量精度,但应用于200km及以上的线路的零序参数测量会造成很大的误差,而该文提出的测量方法在测量精度和测量效率上都有很大的提高,能够满足实际工程的需求。展开更多
文摘A soft switching three-transistor push-pull(TTPP)converter is proposed in this paper. The 3rd transistor is inserted in the primary side of a traditional push-pull converter. Two primitive transistors can achieve zero-voltage-switching (ZVS) easily under a wide load range, the 3rd transistor can also realize zero-voltage-switching assisted by leakage inductance. The rated voltage of the 3rd transistor is half of that of the main transistors. The operation theory is explained in detail. The soft-switching realization conditions are derived. An 800 W with 83.3 kHz switching frequency prototype has been built. The experimental result is provided to verify the analysis.
文摘超高压(extra high voltage,EHV)同塔三回线路复杂的电磁耦合给其零序参数的精确测量带来极大的挑战。该文总结了现有的零序参数测量方法,分析了各测量方法的优缺点。在此基础上提出了一种基于双端同步测量的EHV同塔三回线路零序参数的精确测量方法。建立了长距离EHV同塔三回线路的分布参数模型,推导了利用双端同步测量信息的同塔三回线路传输线方程的求解公式,给出了同塔三回线路的测量接线方式和零序参数的测量步骤,利用PSCAD/EMTDC验证了所提测量方法的准确性,并与传统测量方法进行了对比。仿真结果表明:传统方法测量精度低,改进的传统方法能提高短距离输电线路的测量精度,但应用于200km及以上的线路的零序参数测量会造成很大的误差,而该文提出的测量方法在测量精度和测量效率上都有很大的提高,能够满足实际工程的需求。
