To achieve economical compensation for the huge-capacity negative sequence currents generated by high-speed railway load, an electromagnetic hybrid compensation system(EHCS) and control strategy is proposed.The EHCS i...To achieve economical compensation for the huge-capacity negative sequence currents generated by high-speed railway load, an electromagnetic hybrid compensation system(EHCS) and control strategy is proposed.The EHCS is made up of a small-capacity railway static power conditioner(RPC) and a large-capacity magnetic static var compensator(MSVC). Compared with traditional compensation methods, the EHCS makes full use of the SVC’s advantages of economy and reliability and of RPC’s advantages of technical capability and flexibility. Based on the idea of injecting a negative sequence, the compensation principle of the EHCS is analyzed in detail. Then the minimum installation capacity of an EHCS is theoretically deduced. Furthermore, a constraint optimization compensation strategy that meets national standards, which reduces compensation capacity further, is proposed. An experimental platform based on a digital signal processor(DSP) and a programmable logic controller(PLC) is built to verify the analysis. Simulated and experimental results are given to demonstrate the effectiveness and feasibility of the proposed method.展开更多
AC / DC converter is a kind of devices applicable to reactive power compensation. Three parameters including losses, Total Harmonic Distortion （THD） and compensation capacity have important role in designing procedu...AC / DC converter is a kind of devices applicable to reactive power compensation. Three parameters including losses, Total Harmonic Distortion （THD） and compensation capacity have important role in designing procedure that these parameters are affected by the firing angle. Consideration trade of between these parameters can cause be selected suitable firing angle for optimal working of the compensator. In this paper is defined an objective function which includes the above parameters. This objective function is optimized through appropriate weighting factor for any parameters and the optimal firing angle will be obtained. So, the mention parameters can be selected optimally.展开更多
针对基于模块化多电平换流器的高压直流输电系统(modular multilevel converter based high voltage direct current,MMC-HVDC),研究了交流系统对MMC-HVDC稳态运行范围的影响并且揭示了限制直流功率输送能力的关键因素。首先,文章基于...针对基于模块化多电平换流器的高压直流输电系统(modular multilevel converter based high voltage direct current,MMC-HVDC),研究了交流系统对MMC-HVDC稳态运行范围的影响并且揭示了限制直流功率输送能力的关键因素。首先,文章基于一个单端的MMC-HVDC系统,列写出完整的数学模型。其次,分别研究了交流系统短路比、换流变压器容量和换流站容量对换流站稳态运行范围的影响。最后,研究了并联无功补偿电容器对MMC-HVDC运行范围的影响。计算结果表明,当交流系统短路比较大时,MMC-HVDC的运行范围主要受到换流变压器容量的限制;当交流系统短路比较小时,MMC-HVDC的运行范围主要受到交流系统短路比的限制。此外,无功补偿电容能改善MMCHVDC的运行范围。展开更多
基金supported by National Key Technology Support Program(No.2013BAA02B00)National Natural Science Foundation of China(No.50807041)+3 种基金Asia Pacific Economic Cooperation FundHubei province science and technology support program(No.2014BAA013)the Fundamental Research Funds for the Central Universities(No.2042014kf0233)the Fundamental Research Funds for the Central Universities(No.2014207020202)
文摘To achieve economical compensation for the huge-capacity negative sequence currents generated by high-speed railway load, an electromagnetic hybrid compensation system(EHCS) and control strategy is proposed.The EHCS is made up of a small-capacity railway static power conditioner(RPC) and a large-capacity magnetic static var compensator(MSVC). Compared with traditional compensation methods, the EHCS makes full use of the SVC’s advantages of economy and reliability and of RPC’s advantages of technical capability and flexibility. Based on the idea of injecting a negative sequence, the compensation principle of the EHCS is analyzed in detail. Then the minimum installation capacity of an EHCS is theoretically deduced. Furthermore, a constraint optimization compensation strategy that meets national standards, which reduces compensation capacity further, is proposed. An experimental platform based on a digital signal processor(DSP) and a programmable logic controller(PLC) is built to verify the analysis. Simulated and experimental results are given to demonstrate the effectiveness and feasibility of the proposed method.
文摘AC / DC converter is a kind of devices applicable to reactive power compensation. Three parameters including losses, Total Harmonic Distortion （THD） and compensation capacity have important role in designing procedure that these parameters are affected by the firing angle. Consideration trade of between these parameters can cause be selected suitable firing angle for optimal working of the compensator. In this paper is defined an objective function which includes the above parameters. This objective function is optimized through appropriate weighting factor for any parameters and the optimal firing angle will be obtained. So, the mention parameters can be selected optimally.
文摘针对基于模块化多电平换流器的高压直流输电系统(modular multilevel converter based high voltage direct current,MMC-HVDC),研究了交流系统对MMC-HVDC稳态运行范围的影响并且揭示了限制直流功率输送能力的关键因素。首先,文章基于一个单端的MMC-HVDC系统,列写出完整的数学模型。其次,分别研究了交流系统短路比、换流变压器容量和换流站容量对换流站稳态运行范围的影响。最后,研究了并联无功补偿电容器对MMC-HVDC运行范围的影响。计算结果表明,当交流系统短路比较大时,MMC-HVDC的运行范围主要受到换流变压器容量的限制;当交流系统短路比较小时,MMC-HVDC的运行范围主要受到交流系统短路比的限制。此外,无功补偿电容能改善MMCHVDC的运行范围。
