This article presents an extensive examination and modeling of Capacitor Coupled Substations (CCS), noting some of their inherent constraints. The underlying implementation of a CCS is to supply electricity directly f...This article presents an extensive examination and modeling of Capacitor Coupled Substations (CCS), noting some of their inherent constraints. The underlying implementation of a CCS is to supply electricity directly from high-voltage (HV) transmission lines to low-voltage (LV) consumers through coupling capacitors and is said to be cost-effective as compared to conventional distribution networks. However, the functionality of such substations is susceptible to various transient phenomena, including ferroresonance and overvoltage occurrences. To address these challenges, the study uses simulations to evaluate the effectiveness of conventional resistor-inductor-capacitor (RLC) filter in mitigating hazardous overvoltage resulting from transients. The proposed methodology entails using standard RLC filter to suppress transients and its associated overvoltage risks. Through a series of MATLAB/Simulink simulations, the research emphasizes the practical effectiveness of this technique. The study examines the impact of transients under varied operational scenarios, including no-load switching conditions, temporary short-circuits, and load on/off events. The primary aim of the article is to assess the viability of using an established technology to manage system instabilities upon the energization of a CCS under no-load circumstances or in case of a short-circuit fault occurring on the primary side of the CCS distribution transformer. The findings underscore the effectiveness of conventional RLC filters in suppressing transients induced by the CCS no-load switching.展开更多
针对3GPP最新发布的LTE(long term evolution)Release 8标准,研究了LTE空中接口协议栈无线链路控制(radio link control,RLC)的子层确认(acknowledged mode,AM)传输模式的设计与实现机制。主要介绍了LTE无线接入网空中接口协议栈的结构...针对3GPP最新发布的LTE(long term evolution)Release 8标准,研究了LTE空中接口协议栈无线链路控制(radio link control,RLC)的子层确认(acknowledged mode,AM)传输模式的设计与实现机制。主要介绍了LTE无线接入网空中接口协议栈的结构,详细阐述了空中接口协议栈中RLC的AM数据传输模式的运行原理,最后根据协议设计了一种具体在协议栈软件中实现AM传输模式的方法。展开更多
为了研究RLC电路弹簧耦合系统的非线性振动,用统一的能量法考虑机电耦合系统的电场能、磁场能和机械能,应用拉格朗日-麦克斯韦方程建立起一个受到简谐激励的RLC电路弹簧耦合系统的数学模型,该机电耦合系统具有平方非线性。根据线性振动...为了研究RLC电路弹簧耦合系统的非线性振动,用统一的能量法考虑机电耦合系统的电场能、磁场能和机械能,应用拉格朗日-麦克斯韦方程建立起一个受到简谐激励的RLC电路弹簧耦合系统的数学模型,该机电耦合系统具有平方非线性。根据线性振动理论对系统运动微分方程组进行分析,得到了一个受简谐激励的M ath ieu方程,通过积分变换,得到了M ath ieu方程的级数形式解。分别用龙格库塔法和级数法计算了在无外激励的情况下,有阻尼和无阻尼时系统分别对应的时间响应,通过M atlab软件进行模拟分析,发现二者得到的响应曲线吻合,证明了级数法对分析类似系统是个很有效的手段。展开更多
文摘This article presents an extensive examination and modeling of Capacitor Coupled Substations (CCS), noting some of their inherent constraints. The underlying implementation of a CCS is to supply electricity directly from high-voltage (HV) transmission lines to low-voltage (LV) consumers through coupling capacitors and is said to be cost-effective as compared to conventional distribution networks. However, the functionality of such substations is susceptible to various transient phenomena, including ferroresonance and overvoltage occurrences. To address these challenges, the study uses simulations to evaluate the effectiveness of conventional resistor-inductor-capacitor (RLC) filter in mitigating hazardous overvoltage resulting from transients. The proposed methodology entails using standard RLC filter to suppress transients and its associated overvoltage risks. Through a series of MATLAB/Simulink simulations, the research emphasizes the practical effectiveness of this technique. The study examines the impact of transients under varied operational scenarios, including no-load switching conditions, temporary short-circuits, and load on/off events. The primary aim of the article is to assess the viability of using an established technology to manage system instabilities upon the energization of a CCS under no-load circumstances or in case of a short-circuit fault occurring on the primary side of the CCS distribution transformer. The findings underscore the effectiveness of conventional RLC filters in suppressing transients induced by the CCS no-load switching.
文摘针对3GPP最新发布的LTE(long term evolution)Release 8标准,研究了LTE空中接口协议栈无线链路控制(radio link control,RLC)的子层确认(acknowledged mode,AM)传输模式的设计与实现机制。主要介绍了LTE无线接入网空中接口协议栈的结构,详细阐述了空中接口协议栈中RLC的AM数据传输模式的运行原理,最后根据协议设计了一种具体在协议栈软件中实现AM传输模式的方法。
文摘为了研究RLC电路弹簧耦合系统的非线性振动,用统一的能量法考虑机电耦合系统的电场能、磁场能和机械能,应用拉格朗日-麦克斯韦方程建立起一个受到简谐激励的RLC电路弹簧耦合系统的数学模型,该机电耦合系统具有平方非线性。根据线性振动理论对系统运动微分方程组进行分析,得到了一个受简谐激励的M ath ieu方程,通过积分变换,得到了M ath ieu方程的级数形式解。分别用龙格库塔法和级数法计算了在无外激励的情况下,有阻尼和无阻尼时系统分别对应的时间响应,通过M atlab软件进行模拟分析,发现二者得到的响应曲线吻合,证明了级数法对分析类似系统是个很有效的手段。
