Recently,ultrasonic waves had been introduced as the transmission medium in Body Area Networks(BANs) to reduce the incalculable damage caused by radio waves. However,the communications based on ultrasonic waves suffer...Recently,ultrasonic waves had been introduced as the transmission medium in Body Area Networks(BANs) to reduce the incalculable damage caused by radio waves. However,the communications based on ultrasonic waves suffer from poor propagation of signals in air and consume too much energy. To address these limitations,firstly,we make the theoretical analysis to ensure ultrasonic waves could be used in BANs(UBANs). Then,we propose an error control strategy in UBANs to dynamically adjust the error control scheme and the Max-Retries based on the current channel state,which is called UECS. The UECS is based on IEEE 802.15.6 standards and considering the characteristics of ultrasonic waves in BANs. Simulation results show that UECS achieves better performance in terms of packet delivery ratio and energy consumption compared with the traditional strategies.展开更多
Performance index based analysis is made to examine and highlight the effective application of Particle Swarm Optimization (PSO) to optimize the Proportional Integral gains for Load Frequency Control (LFC) in a restru...Performance index based analysis is made to examine and highlight the effective application of Particle Swarm Optimization (PSO) to optimize the Proportional Integral gains for Load Frequency Control (LFC) in a restructured power system that operates under Bilateral based policy scheme. Various Integral Performance Criteria measures are taken as fitness function in PSO and are compared using overshoot, settling time and frequency and tie-line power deviation following a step load perturbation (SLP). The motivation for using different fitness technique in PSO is to show the behavior of the controller for a wide range of system parameters and load changes. Error based analysis with parametric uncertainties and load changes are tested on a two-area restructured power system. The results of the proposed PSO based controller show the better performance compared to the classical Ziegler-Nichols (Z-N) tuned PI and Fuzzy Rule based PI controller.展开更多
文章以电池储能系统参与电力系统二次调频为研究对象,提出了一种基于小波变换的储能参与电网二次调频容量优化配置方法。区别于传统容量配置方法中储能系统和火电机组采用定比例功率分配方法,该容量配置方法采用小波变换对初始区域控制...文章以电池储能系统参与电力系统二次调频为研究对象,提出了一种基于小波变换的储能参与电网二次调频容量优化配置方法。区别于传统容量配置方法中储能系统和火电机组采用定比例功率分配方法,该容量配置方法采用小波变换对初始区域控制偏差(Area Control Error,ACE)信号进行分解重组和再分配,将高频信号分配给储能系统,将低频信号分配给火电机组;然后建立储能参与电网调频的成本-效益模型,分析不同重组点下的调频效果指标和净效益,得出最终的容量配置结果;最后,基于实测的ACE信号验证了配置结果的合理性和有效性。展开更多
随着风电、光伏等波动性强的可再生电源接入百色区域电网,系统的频率稳定面临严峻的挑战。储能具有响应速度快、调节灵活等优点将成为区域电网辅助调频的重要手段。首先建立了包含火电机组、储能、网机接口、联络线在内的区域电网频率...随着风电、光伏等波动性强的可再生电源接入百色区域电网,系统的频率稳定面临严峻的挑战。储能具有响应速度快、调节灵活等优点将成为区域电网辅助调频的重要手段。首先建立了包含火电机组、储能、网机接口、联络线在内的区域电网频率调节模型,然后根据实时的区域控制偏差(Area control error,ACE)信号生成系统调频需求,并利用MATLAB/Simulink仿真平台对所提模型进行仿真。结果表明系统受到扰动后,储能参与系统自动发电控制(Automatic Generation Control,AGC)调节能够有效改善区域电网的调频效果。展开更多
Controller area network(CAN) is a widely used fieldbus protocol in various industrial applications.To understand the network behavior under errors for the optimal design of networked control systems, the message respo...Controller area network(CAN) is a widely used fieldbus protocol in various industrial applications.To understand the network behavior under errors for the optimal design of networked control systems, the message response time of the CAN network needs to be analyzed. In this study, a novel delay time distribution analysis method for the response messages is proposed when considering errors. In this method the complex message queues are decomposed into typical message patterns and cases. First, a stochastic fault model is developed, and the probability factor is defined to calculate the error distribution. Then the message delay time distribution for the single slave node configuration is analyzed based on the error distribution. Next, based on the delay time distribution analysis of typical patterns and cases, an analysis framework of message delay time distribution for the master/slave configuration is developed. The testbed is constructed and case studies are conducted to demonstrate the proposed methodology under different network configurations. Experimental results show that the delay time distributions calculated by the proposed method agree well with the actual observations.展开更多
针对AGC控制中火电机组响应时滞长、机组爬坡速率低的问题,提出了一种基于模糊控制策略的电池储能系统(Battery Energy Storage System,BESS)辅助AGC调频方法。该方法以区域控制偏差(Area Control Error,ACE)及其变化率作为模糊控制器...针对AGC控制中火电机组响应时滞长、机组爬坡速率低的问题,提出了一种基于模糊控制策略的电池储能系统(Battery Energy Storage System,BESS)辅助AGC调频方法。该方法以区域控制偏差(Area Control Error,ACE)及其变化率作为模糊控制器的输入量,BESS的参考功率变化量作为输出量,根据系统的运行状态调节BESS输出功率,辅助火电机组改善电网的动态调频性能。基于Matlab/Simulink平台的仿真结果表明,BESS能够迅速响应负荷扰动,减小了系统频率偏差和联络线功率偏差,降低了系统的超调作用,有助于提高电网AGC调频能力和增强系统的稳定性。展开更多
正常运行时互联电网交流联络线上存在随机功率波动的现象。基于实际2大区互联电网的历史数据,分析了联络线功率偏差、频率偏差以及2大区电网区域控制偏差(area control error,ACE)的统计特性,结果显示:联络线功率偏差表现出良好的正态...正常运行时互联电网交流联络线上存在随机功率波动的现象。基于实际2大区互联电网的历史数据,分析了联络线功率偏差、频率偏差以及2大区电网区域控制偏差(area control error,ACE)的统计特性,结果显示:联络线功率偏差表现出良好的正态分布特性;系统频率偏差和正态分布存在较大差别,原因是电网的频率控制使得频率偏差大于0.03 Hz的概率减小;各控制区的ACE基本服从正态分布。文章认为联络线功率偏差由两端电网的ACE引起,可以通过两端电网ACE的均方根值和相关系数计算出联络线功率偏差的均方根值,从而得到对联络线功率偏差大小分布的估计。对目前采用的T标准进行了分析,得出结论:为实现联络线功率控制的目标,两端电网责任度阈值之和为2即可,不一定要求两端电网责任度的阈值都是1;两端电网责任度阈值的分配还需要综合考虑各种因素进行详细研究,以得到公平合理的方案。展开更多
基金partly supported by the National Natural Science Foundation of China(Grant No.61272412)Project 2016194 Supported by Graduate Innovation Fund of Jilin UniversitySpecialized Research Fund for the Doctoral Program of Higher Education under Grant Nos.20120061110044
文摘Recently,ultrasonic waves had been introduced as the transmission medium in Body Area Networks(BANs) to reduce the incalculable damage caused by radio waves. However,the communications based on ultrasonic waves suffer from poor propagation of signals in air and consume too much energy. To address these limitations,firstly,we make the theoretical analysis to ensure ultrasonic waves could be used in BANs(UBANs). Then,we propose an error control strategy in UBANs to dynamically adjust the error control scheme and the Max-Retries based on the current channel state,which is called UECS. The UECS is based on IEEE 802.15.6 standards and considering the characteristics of ultrasonic waves in BANs. Simulation results show that UECS achieves better performance in terms of packet delivery ratio and energy consumption compared with the traditional strategies.
文摘Performance index based analysis is made to examine and highlight the effective application of Particle Swarm Optimization (PSO) to optimize the Proportional Integral gains for Load Frequency Control (LFC) in a restructured power system that operates under Bilateral based policy scheme. Various Integral Performance Criteria measures are taken as fitness function in PSO and are compared using overshoot, settling time and frequency and tie-line power deviation following a step load perturbation (SLP). The motivation for using different fitness technique in PSO is to show the behavior of the controller for a wide range of system parameters and load changes. Error based analysis with parametric uncertainties and load changes are tested on a two-area restructured power system. The results of the proposed PSO based controller show the better performance compared to the classical Ziegler-Nichols (Z-N) tuned PI and Fuzzy Rule based PI controller.
文摘文章以电池储能系统参与电力系统二次调频为研究对象,提出了一种基于小波变换的储能参与电网二次调频容量优化配置方法。区别于传统容量配置方法中储能系统和火电机组采用定比例功率分配方法,该容量配置方法采用小波变换对初始区域控制偏差(Area Control Error,ACE)信号进行分解重组和再分配,将高频信号分配给储能系统,将低频信号分配给火电机组;然后建立储能参与电网调频的成本-效益模型,分析不同重组点下的调频效果指标和净效益,得出最终的容量配置结果;最后,基于实测的ACE信号验证了配置结果的合理性和有效性。
文摘随着风电、光伏等波动性强的可再生电源接入百色区域电网,系统的频率稳定面临严峻的挑战。储能具有响应速度快、调节灵活等优点将成为区域电网辅助调频的重要手段。首先建立了包含火电机组、储能、网机接口、联络线在内的区域电网频率调节模型,然后根据实时的区域控制偏差(Area control error,ACE)信号生成系统调频需求,并利用MATLAB/Simulink仿真平台对所提模型进行仿真。结果表明系统受到扰动后,储能参与系统自动发电控制(Automatic Generation Control,AGC)调节能够有效改善区域电网的调频效果。
基金the National Natural Science Foundation of China (Nos. 51475422 and 51521064).
文摘Controller area network(CAN) is a widely used fieldbus protocol in various industrial applications.To understand the network behavior under errors for the optimal design of networked control systems, the message response time of the CAN network needs to be analyzed. In this study, a novel delay time distribution analysis method for the response messages is proposed when considering errors. In this method the complex message queues are decomposed into typical message patterns and cases. First, a stochastic fault model is developed, and the probability factor is defined to calculate the error distribution. Then the message delay time distribution for the single slave node configuration is analyzed based on the error distribution. Next, based on the delay time distribution analysis of typical patterns and cases, an analysis framework of message delay time distribution for the master/slave configuration is developed. The testbed is constructed and case studies are conducted to demonstrate the proposed methodology under different network configurations. Experimental results show that the delay time distributions calculated by the proposed method agree well with the actual observations.
文摘针对AGC控制中火电机组响应时滞长、机组爬坡速率低的问题,提出了一种基于模糊控制策略的电池储能系统(Battery Energy Storage System,BESS)辅助AGC调频方法。该方法以区域控制偏差(Area Control Error,ACE)及其变化率作为模糊控制器的输入量,BESS的参考功率变化量作为输出量,根据系统的运行状态调节BESS输出功率,辅助火电机组改善电网的动态调频性能。基于Matlab/Simulink平台的仿真结果表明,BESS能够迅速响应负荷扰动,减小了系统频率偏差和联络线功率偏差,降低了系统的超调作用,有助于提高电网AGC调频能力和增强系统的稳定性。
文摘正常运行时互联电网交流联络线上存在随机功率波动的现象。基于实际2大区互联电网的历史数据,分析了联络线功率偏差、频率偏差以及2大区电网区域控制偏差(area control error,ACE)的统计特性,结果显示:联络线功率偏差表现出良好的正态分布特性;系统频率偏差和正态分布存在较大差别,原因是电网的频率控制使得频率偏差大于0.03 Hz的概率减小;各控制区的ACE基本服从正态分布。文章认为联络线功率偏差由两端电网的ACE引起,可以通过两端电网ACE的均方根值和相关系数计算出联络线功率偏差的均方根值,从而得到对联络线功率偏差大小分布的估计。对目前采用的T标准进行了分析,得出结论:为实现联络线功率控制的目标,两端电网责任度阈值之和为2即可,不一定要求两端电网责任度的阈值都是1;两端电网责任度阈值的分配还需要综合考虑各种因素进行详细研究,以得到公平合理的方案。
