基于接收信号强度差(Difference of Received Signal Strength, DRSS)的定位模型具有节省能量、带宽和时间的优点,并且在定位过程中隐藏了发射机的传输方式,非常有益于机密监视或军事应用。然而DRSS模型具有较高的非凸性,在定位求解时...基于接收信号强度差(Difference of Received Signal Strength, DRSS)的定位模型具有节省能量、带宽和时间的优点,并且在定位过程中隐藏了发射机的传输方式,非常有益于机密监视或军事应用。然而DRSS模型具有较高的非凸性,在定位求解时比较困难,本文提出了一种改进的定位方法——相对误差及凸优化混合定位方法。首先借助相对误差方法构建最小化问题,然后借助半正定规划和二阶锥规划对模型进行近似求解。为了验证所提方法的有效性,引入均方根误差(Root Mean Square Error, RMSE)作为估计方法精度的评判标准,通过对比本文所提方法以及现有四种方法(A-BLUE、U-BLUE、LARE-SDP、SOCP)的RMSE,研究结果发现本文提出方法的RMSE值最低,并且更加贴近理论误差的CRLB下界。The positioning model based on Difference of Received Signal Strength (DRSS) has the advantages of saving energy, bandwidth, and time, and hides the transmission mode of the transmitter during the positioning process, which is very beneficial for confidential monitoring or military applications. However, the DRSS model has high nonconvexity and is difficult to solve in localization. This paper proposes an improved localization method—a hybrid localization method of relative error and convex optimization. Firstly, the minimization problem is constructed using the relative error method, and then the model is approximately solved using semi positive definite programming and second-order cone programming. In order to verify the effectiveness of the proposed method, Root Mean Square Error (RMSE) was introduced as the evaluation criterion for the accuracy of the estimation method. By comparing the RMSE of the proposed method with four existing methods (A-BLUE, U-BLUE, LARE-SDP, SOCP), the research results showed that the RMSE value of the proposed method was the lowest and closer to the CRLB lower bound of the theoretical error.展开更多
求解最优潮流问题(optimal power flow, OPF)的凸松弛技术可将非凸的OPF问题转化为凸优化问题,并在精确松弛的前提下获得原问题的全局最优解。近10年来,该项技术已成为国内外电力系统优化领域的一个研究热点。首先,回顾电力系统优化领...求解最优潮流问题(optimal power flow, OPF)的凸松弛技术可将非凸的OPF问题转化为凸优化问题,并在精确松弛的前提下获得原问题的全局最优解。近10年来,该项技术已成为国内外电力系统优化领域的一个研究热点。首先,回顾电力系统优化领域凸松弛技术的发展过程,介绍半正定规划松弛、二阶锥规划松弛、二次凸包络松弛的基本概念与数学形式。接着,对于凸松弛技术的精确性,总结并梳理保证精确松弛的充分条件和构造更紧凸松弛的方法。最后,从技术手段与应用场景两个方面对OPF凸松弛技术未来的研究方向做出展望。展开更多
柔性互联装置的广泛应用给主动配电网(active distribution network,ADN)规划带来巨大挑战。该文提出一种考虑智能软开关(soft open point,SOP)接入的ADN扩展规划方法,对变电站新建及扩容,线路新建,智能软开关、分布式电源、储能系统以...柔性互联装置的广泛应用给主动配电网(active distribution network,ADN)规划带来巨大挑战。该文提出一种考虑智能软开关(soft open point,SOP)接入的ADN扩展规划方法,对变电站新建及扩容,线路新建,智能软开关、分布式电源、储能系统以及无功补偿等设备的选址定容进行协同规划。首先,考虑分布式电源出力和负荷功率不确定性,采用基于改进高斯混合模型的聚类方法构建典型日场景。在此基础上,以年综合费用最小为目标函数,建立了考虑SOP接入的ADN扩展规划模型。然后,通过线性化和二阶锥松弛技术,将原始非凸非线性规划模型转化为混合整数二阶锥规划(mixed-integer second-order cone programming,MISOCP)模型,并提出逐次收缩凸松弛算法以获得凸松弛间隙足够小的原问题最优解。最后,在54节点主动配电网算例上验证了所提规划模型和求解算法的可行性与有效性。展开更多
文摘基于接收信号强度差(Difference of Received Signal Strength, DRSS)的定位模型具有节省能量、带宽和时间的优点,并且在定位过程中隐藏了发射机的传输方式,非常有益于机密监视或军事应用。然而DRSS模型具有较高的非凸性,在定位求解时比较困难,本文提出了一种改进的定位方法——相对误差及凸优化混合定位方法。首先借助相对误差方法构建最小化问题,然后借助半正定规划和二阶锥规划对模型进行近似求解。为了验证所提方法的有效性,引入均方根误差(Root Mean Square Error, RMSE)作为估计方法精度的评判标准,通过对比本文所提方法以及现有四种方法(A-BLUE、U-BLUE、LARE-SDP、SOCP)的RMSE,研究结果发现本文提出方法的RMSE值最低,并且更加贴近理论误差的CRLB下界。The positioning model based on Difference of Received Signal Strength (DRSS) has the advantages of saving energy, bandwidth, and time, and hides the transmission mode of the transmitter during the positioning process, which is very beneficial for confidential monitoring or military applications. However, the DRSS model has high nonconvexity and is difficult to solve in localization. This paper proposes an improved localization method—a hybrid localization method of relative error and convex optimization. Firstly, the minimization problem is constructed using the relative error method, and then the model is approximately solved using semi positive definite programming and second-order cone programming. In order to verify the effectiveness of the proposed method, Root Mean Square Error (RMSE) was introduced as the evaluation criterion for the accuracy of the estimation method. By comparing the RMSE of the proposed method with four existing methods (A-BLUE, U-BLUE, LARE-SDP, SOCP), the research results showed that the RMSE value of the proposed method was the lowest and closer to the CRLB lower bound of the theoretical error.
文摘求解最优潮流问题(optimal power flow, OPF)的凸松弛技术可将非凸的OPF问题转化为凸优化问题,并在精确松弛的前提下获得原问题的全局最优解。近10年来,该项技术已成为国内外电力系统优化领域的一个研究热点。首先,回顾电力系统优化领域凸松弛技术的发展过程,介绍半正定规划松弛、二阶锥规划松弛、二次凸包络松弛的基本概念与数学形式。接着,对于凸松弛技术的精确性,总结并梳理保证精确松弛的充分条件和构造更紧凸松弛的方法。最后,从技术手段与应用场景两个方面对OPF凸松弛技术未来的研究方向做出展望。
文摘柔性互联装置的广泛应用给主动配电网(active distribution network,ADN)规划带来巨大挑战。该文提出一种考虑智能软开关(soft open point,SOP)接入的ADN扩展规划方法,对变电站新建及扩容,线路新建,智能软开关、分布式电源、储能系统以及无功补偿等设备的选址定容进行协同规划。首先,考虑分布式电源出力和负荷功率不确定性,采用基于改进高斯混合模型的聚类方法构建典型日场景。在此基础上,以年综合费用最小为目标函数,建立了考虑SOP接入的ADN扩展规划模型。然后,通过线性化和二阶锥松弛技术,将原始非凸非线性规划模型转化为混合整数二阶锥规划(mixed-integer second-order cone programming,MISOCP)模型,并提出逐次收缩凸松弛算法以获得凸松弛间隙足够小的原问题最优解。最后,在54节点主动配电网算例上验证了所提规划模型和求解算法的可行性与有效性。
