-Starting from physical oceanology characteristics of the China seas and for the short-term operational prediction of SST in the region, a two-dimensional (vertically integrated) primitive equation model, physically r...-Starting from physical oceanology characteristics of the China seas and for the short-term operational prediction of SST in the region, a two-dimensional (vertically integrated) primitive equation model, physically reasonable and operationally feasible,on the upper mixed layer is constructed and given here, which consists of three parts, the nondivergent residual current (the monthly mean field of the Kuroshio and its branches) equations, the dynamic forecasting equations, and the equation of model's physics consisting of surface heat flux, coolings of the upper mixed layer due to the Ekman pumping and the entrainment by gale. This model may be used primarily to forecast the sea surface temperature, and to give estimations of the mean wind-driven current and the sea level, for a period of 3-5 d. In part 1 of this series, the physical conditions for establishing model equations are discussed first, that is, 1. the existence of the upper well mixed layer in the region; 2. the distinguishability of currents of all kinds; 3. the splitting of thermodynamical equation. The equations of nondivergent residual current, and the dynamic forecasting equations with initial values and boundary conditions are also discussed.展开更多
为了优化区域交通信号配时方案,提升区域通行效率,文章提出一种基于改进多智能体Nash Q Learning的区域交通信号协调控制方法。首先,采用离散化编码方法,通过划分单元格将连续状态信息转化为离散形式。其次,在算法中融入长短时记忆网络(...为了优化区域交通信号配时方案,提升区域通行效率,文章提出一种基于改进多智能体Nash Q Learning的区域交通信号协调控制方法。首先,采用离散化编码方法,通过划分单元格将连续状态信息转化为离散形式。其次,在算法中融入长短时记忆网络(Long Short Term Memory,LSTM)模块,用于从状态数据中挖掘更多的隐藏信息,丰富Q值表中的状态数据。最后,基于微观交通仿真软件SUMO(Simulation of Urban Mobility)的仿真测试结果表明,相较于原始Nash Q Learning交通信号控制方法,所提方法在低、中、高流量下车辆的平均等待时间分别减少了11.5%、16.2%和10.0%,平均排队长度分别减少了9.1%、8.2%和7.6%,平均停车次数分别减少了18.3%、16.1%和10.0%。结果证明了该算法具有更好的控制效果。展开更多
针对弱连接条件下锁相环同步电压源变流器WG-VSC(weak grid connected voltage source converter)系统的暂态同步稳定问题,首先建立了适用于分析WG-VSC系统在严重电网故障期间的锁相环同步暂态稳定问题的等效转子摇摆方程模型。然后利...针对弱连接条件下锁相环同步电压源变流器WG-VSC(weak grid connected voltage source converter)系统的暂态同步稳定问题,首先建立了适用于分析WG-VSC系统在严重电网故障期间的锁相环同步暂态稳定问题的等效转子摇摆方程模型。然后利用改进的等面积定则I-EAC(improved equal area criterion)揭示了弱连接条件下VSC并网系统在严重电网故障下的暂态同步失稳机理;在此基础上,给出了系统在严重电网故障等大扰动下的保证系统暂态稳定的注入电流暂态稳定域的解析边界,为故障期间注入电流策略的制定提供了理论依据。最后,在PSCAD/EMTDC搭建了WG-VSC系统的详细开关模型,仿真结果验证了等效转子摇摆方程模型以及注入电流稳定域的有效性。展开更多
文摘-Starting from physical oceanology characteristics of the China seas and for the short-term operational prediction of SST in the region, a two-dimensional (vertically integrated) primitive equation model, physically reasonable and operationally feasible,on the upper mixed layer is constructed and given here, which consists of three parts, the nondivergent residual current (the monthly mean field of the Kuroshio and its branches) equations, the dynamic forecasting equations, and the equation of model's physics consisting of surface heat flux, coolings of the upper mixed layer due to the Ekman pumping and the entrainment by gale. This model may be used primarily to forecast the sea surface temperature, and to give estimations of the mean wind-driven current and the sea level, for a period of 3-5 d. In part 1 of this series, the physical conditions for establishing model equations are discussed first, that is, 1. the existence of the upper well mixed layer in the region; 2. the distinguishability of currents of all kinds; 3. the splitting of thermodynamical equation. The equations of nondivergent residual current, and the dynamic forecasting equations with initial values and boundary conditions are also discussed.
文摘为了优化区域交通信号配时方案,提升区域通行效率,文章提出一种基于改进多智能体Nash Q Learning的区域交通信号协调控制方法。首先,采用离散化编码方法,通过划分单元格将连续状态信息转化为离散形式。其次,在算法中融入长短时记忆网络(Long Short Term Memory,LSTM)模块,用于从状态数据中挖掘更多的隐藏信息,丰富Q值表中的状态数据。最后,基于微观交通仿真软件SUMO(Simulation of Urban Mobility)的仿真测试结果表明,相较于原始Nash Q Learning交通信号控制方法,所提方法在低、中、高流量下车辆的平均等待时间分别减少了11.5%、16.2%和10.0%,平均排队长度分别减少了9.1%、8.2%和7.6%,平均停车次数分别减少了18.3%、16.1%和10.0%。结果证明了该算法具有更好的控制效果。
文摘针对弱连接条件下锁相环同步电压源变流器WG-VSC(weak grid connected voltage source converter)系统的暂态同步稳定问题,首先建立了适用于分析WG-VSC系统在严重电网故障期间的锁相环同步暂态稳定问题的等效转子摇摆方程模型。然后利用改进的等面积定则I-EAC(improved equal area criterion)揭示了弱连接条件下VSC并网系统在严重电网故障下的暂态同步失稳机理;在此基础上,给出了系统在严重电网故障等大扰动下的保证系统暂态稳定的注入电流暂态稳定域的解析边界,为故障期间注入电流策略的制定提供了理论依据。最后,在PSCAD/EMTDC搭建了WG-VSC系统的详细开关模型,仿真结果验证了等效转子摇摆方程模型以及注入电流稳定域的有效性。
