There are multiple operating modes in the real industrial process, and the collected data follow the complex multimodal distribution, so most traditional process monitoring methods are no longer applicable because the...There are multiple operating modes in the real industrial process, and the collected data follow the complex multimodal distribution, so most traditional process monitoring methods are no longer applicable because their presumptions are that sampled-data should obey the single Gaussian distribution or non-Gaussian distribution. In order to solve these problems, a novel weighted local standardization(WLS) strategy is proposed to standardize the multimodal data, which can eliminate the multi-mode characteristics of the collected data, and normalize them into unimodal data distribution. After detailed analysis of the raised data preprocessing strategy, a new algorithm using WLS strategy with support vector data description(SVDD) is put forward to apply for multi-mode monitoring process. Unlike the strategy of building multiple local models, the developed method only contains a model without the prior knowledge of multi-mode process. To demonstrate the proposed method's validity, it is applied to a numerical example and a Tennessee Eastman(TE) process. Finally, the simulation results show that the WLS strategy is very effective to standardize multimodal data, and the WLS-SVDD monitoring method has great advantages over the traditional SVDD and PCA combined with a local standardization strategy(LNS-PCA) in multi-mode process monitoring.展开更多
电力系统稳定器(power system stabilizer,PSS)参数配置不合理将会导致低频振荡的抑制效果不佳,严重情况下还会破坏电网运行的稳定性,为此,建立发电机、励磁系统和PSS的线性化方程,构建多种运行方式、多机电振荡模式下的目标函数,对PSS...电力系统稳定器(power system stabilizer,PSS)参数配置不合理将会导致低频振荡的抑制效果不佳,严重情况下还会破坏电网运行的稳定性,为此,建立发电机、励磁系统和PSS的线性化方程,构建多种运行方式、多机电振荡模式下的目标函数,对PSS参数进行优化;将差分进化(differential evolution,DE)算法与生物地理学优化(biogeography based optimization,BBO)算法相结合,针对迁移算子和变异部分进行改进;在PSASP中搭建云南电网的滇西北部分电网,通过仿真验证所提PSS优化目标函数和改进的BBO-DE优化算法的有效性,使得PSS的优化参数具有良好的适应性,有效提高系统的阻尼比,能够适应云南电网的多种运行方式。展开更多
针对包含多端柔性直流输电(voltage source converter based multi-terminal direct current transmission,VSC-MTDC)的交直流混合系统中出现的次同步振荡(sub-synchronous oscillation,SSO),研究设计了适用于系统各种运行方式、更具通...针对包含多端柔性直流输电(voltage source converter based multi-terminal direct current transmission,VSC-MTDC)的交直流混合系统中出现的次同步振荡(sub-synchronous oscillation,SSO),研究设计了适用于系统各种运行方式、更具通用性的次同步阻尼控制器(sub-synchronous oscillation damping controller,SSDC)。首先针对研究交直流混合系统的拓扑结构,分析了其运行方式、变换器控制模式及对SSO抑制的影响;然后提出了适用于变换器多种控制模式的更具通用性的SSDC设计新方法;随后分析了用该方法设计的SSDC对系统电气阻尼特性的改善情况;最后在PSCAD/EMTDC上搭建335电平仿真模型。仿真结果验证了SSDC设计新方法的正确性和有效性。研究表明:利用新方法设计的SSDC可以显著增强系统的电气阻尼,有效降低系统处于各种运行方式下发生SSO的风险,通用性强。展开更多
基金Project(61374140)supported by the National Natural Science Foundation of China
文摘There are multiple operating modes in the real industrial process, and the collected data follow the complex multimodal distribution, so most traditional process monitoring methods are no longer applicable because their presumptions are that sampled-data should obey the single Gaussian distribution or non-Gaussian distribution. In order to solve these problems, a novel weighted local standardization(WLS) strategy is proposed to standardize the multimodal data, which can eliminate the multi-mode characteristics of the collected data, and normalize them into unimodal data distribution. After detailed analysis of the raised data preprocessing strategy, a new algorithm using WLS strategy with support vector data description(SVDD) is put forward to apply for multi-mode monitoring process. Unlike the strategy of building multiple local models, the developed method only contains a model without the prior knowledge of multi-mode process. To demonstrate the proposed method's validity, it is applied to a numerical example and a Tennessee Eastman(TE) process. Finally, the simulation results show that the WLS strategy is very effective to standardize multimodal data, and the WLS-SVDD monitoring method has great advantages over the traditional SVDD and PCA combined with a local standardization strategy(LNS-PCA) in multi-mode process monitoring.
文摘电力系统稳定器(power system stabilizer,PSS)参数配置不合理将会导致低频振荡的抑制效果不佳,严重情况下还会破坏电网运行的稳定性,为此,建立发电机、励磁系统和PSS的线性化方程,构建多种运行方式、多机电振荡模式下的目标函数,对PSS参数进行优化;将差分进化(differential evolution,DE)算法与生物地理学优化(biogeography based optimization,BBO)算法相结合,针对迁移算子和变异部分进行改进;在PSASP中搭建云南电网的滇西北部分电网,通过仿真验证所提PSS优化目标函数和改进的BBO-DE优化算法的有效性,使得PSS的优化参数具有良好的适应性,有效提高系统的阻尼比,能够适应云南电网的多种运行方式。
文摘针对包含多端柔性直流输电(voltage source converter based multi-terminal direct current transmission,VSC-MTDC)的交直流混合系统中出现的次同步振荡(sub-synchronous oscillation,SSO),研究设计了适用于系统各种运行方式、更具通用性的次同步阻尼控制器(sub-synchronous oscillation damping controller,SSDC)。首先针对研究交直流混合系统的拓扑结构,分析了其运行方式、变换器控制模式及对SSO抑制的影响;然后提出了适用于变换器多种控制模式的更具通用性的SSDC设计新方法;随后分析了用该方法设计的SSDC对系统电气阻尼特性的改善情况;最后在PSCAD/EMTDC上搭建335电平仿真模型。仿真结果验证了SSDC设计新方法的正确性和有效性。研究表明:利用新方法设计的SSDC可以显著增强系统的电气阻尼,有效降低系统处于各种运行方式下发生SSO的风险,通用性强。
