A novel technique for the optimal tuning of power system stabilizer (PSS) was proposed,by integrating the modified particle swarm optimization (MPSO) with the chaos (MPSOC).Firstly,a modification in the particle swarm...A novel technique for the optimal tuning of power system stabilizer (PSS) was proposed,by integrating the modified particle swarm optimization (MPSO) with the chaos (MPSOC).Firstly,a modification in the particle swarm optimization (PSO) was made by introducing passive congregation (PC).It helps each swarm member in receiving a multitude of information from other members and thus decreases the possibility of a failed attempt at detection or a meaningless search.Secondly,the MPSO and chaos were hybridized (MPSOC) to improve the global searching capability and prevent the premature convergence due to local minima.The robustness of the proposed PSS tuning technique was verified on a multi-machine power system under different operating conditions.The performance of the proposed MPSOC was compared to the MPSO,PSO and GA through eigenvalue analysis,nonlinear time-domain simulation and statistical tests.Eigenvalue analysis shows acceptable damping of the low-frequency modes and time domain simulations also show that the oscillations of synchronous machines can be rapidly damped for power systems with the proposed PSSs.The results show that the presented algorithm has a faster convergence rate with higher degree of accuracy than the GA,PSO and MPSO.展开更多
为了演示和验证稳定器设计的就地相位补偿法在多机电力系统中的应用,介绍在多机电力系统中,就地补偿设计稳定器的2个应用实例。第1个实例是在多机电力系统中就地补偿设计电力系统稳定器（power system stabilizer,PSS）,阻尼电力系统局...为了演示和验证稳定器设计的就地相位补偿法在多机电力系统中的应用,介绍在多机电力系统中,就地补偿设计稳定器的2个应用实例。第1个实例是在多机电力系统中就地补偿设计电力系统稳定器（power system stabilizer,PSS）,阻尼电力系统局部模振荡。第2个实例是就地补偿设计附加在静态同步补偿器（static synchronous compensator,STATCOM）上的稳定器,抑制多机电力系统中的区域模振荡,并给出在一个16机电力系统中的应用计算和仿真结果。展开更多
为解决电力系统稳定器(power system stabilizer,PSS)参数设置困难及传统的智能优化算法在寻优的过程中容易陷入局部最优,导致收敛速度下降的问题,因此文中采用混合策略改进SSA算法优化PSS参数。首先采用tent混沌映射来优化初始种群,提...为解决电力系统稳定器(power system stabilizer,PSS)参数设置困难及传统的智能优化算法在寻优的过程中容易陷入局部最优,导致收敛速度下降的问题,因此文中采用混合策略改进SSA算法优化PSS参数。首先采用tent混沌映射来优化初始种群,提高种群多样性;采用柯西变异、正余弦策略和反向学习策略(opposition-based learning,OBL)来提升收敛速度;然后对6种测试函数进行寻优实验,将改进的SSA与PSO、GWO、SSA、SSSA优化结果对比,验证改进的SSA算法具有更好的收敛速度和稳定性;最后,将改进的SSA算法应用在单机无穷大系统及四机二区域系统的PSS参数优化中,与其他算法优化结果比较,验证改进的SSA在PSS参数优化方面的鲁棒性更好,收敛速度更快。展开更多
Small signal instability may cause severe accidents for power system if it can not be dear correctly and timely. How to maintain power system stable under small signal disturbance is a big challenge for power system o...Small signal instability may cause severe accidents for power system if it can not be dear correctly and timely. How to maintain power system stable under small signal disturbance is a big challenge for power system operators and dispatchers. Time delay existing in signal transmission process makes the problem more complex. Conventional eigenvalue analysis method neglects time delay influence and can not precisely describe power system dynamic behaviors. In this work, a modified small signal stability model considering time varying delay influence was constructed and a new time delay controller was proposed to stabilize power system under disturbance. By Lyapunov-Krasovskii function, the control law in the form of nonlinear matrix inequality （NLMI） was derived. Considering synthesis method limitation for time delay controller at present, both parameter adjustment method by using linear matrix inequality （LMI） solver and iteration searching method by solving nonlinear minimization problem were suggested to design the controller. Simulation tests were carried out on synchronous-machine infinite-bus power system. Satisfactory test results verify the correctness of the proposed model and the feasibility of the stabilization approach.展开更多
On the basis of the theoretical analysis of a single-machine infinite-bus （SMIB）, using the modified linearized Phil- lips-Heffron model installed with unified power flow controller （UPFC）, the potential of the UP...On the basis of the theoretical analysis of a single-machine infinite-bus （SMIB）, using the modified linearized Phil- lips-Heffron model installed with unified power flow controller （UPFC）, the potential of the UPFC supplementary controller to enhance the dynamic stability of a power system is evaluated by measuring the electromechanical controllability through singular value decomposition （SVD） analysis. This controller is tuned to simultaneously shift the undamped electromeehanical modes to a prescribed zone in the s-plane. The problem of robust UPFC based damping controller is formulated as an optimization problem according to the eigenvalue-based multi-objective function comprising the damping factor, and the damping ratio of the undamped electromechanical modes to be solved using gravitational search algorithm （GSA） that has a strong ability to find the most optimistic results. The different loading conditions are simulated on a SMIB system and the rotor speed deviation, internal voltage deviation, DC voltage deviation and electrical power deviation responses are studied with the effect of this flexible AC transmission systems （FACTS） controller. The results reveal that the tuned GSA based UPFC controller using the proposed multi-objective function has an excellent capability in damping power system with low frequency oscillations and greatly enhances the dynamic stability of the power systems.展开更多
In order to analyze power system stability in environment of WAMS(wide area measurement system),a new steady state stability model with time-varying delay was proposed for power system.The factors of exciter and power...In order to analyze power system stability in environment of WAMS(wide area measurement system),a new steady state stability model with time-varying delay was proposed for power system.The factors of exciter and power system stabilizer with delay were introduced into analytical model.To decrease conservativeness of stability analysis,an improved Lyapunov-Krasovskii functional was constructed,and then a new delay-dependent steady state stability criterion for power system,which overcomes the disadvantages of eigenvalue computation method,was derived.The proposed model and criterion were tested on synchronous-machine infinite-bus power system.The test results demonstrate that Lyapunov-Krasovskii functional based power system stability analysis method is applicable and effective in the analysis of time delay power system stability.展开更多
The morbidity problem of the GM（1,1） power model in parameter identification is discussed by using multiple and rotation transformation of vectors. Firstly we consider the morbidity problem of the special matrix and...The morbidity problem of the GM（1,1） power model in parameter identification is discussed by using multiple and rotation transformation of vectors. Firstly we consider the morbidity problem of the special matrix and prove that the condition number of the coefficient matrix is determined by the ratio of lengths and the included angle of the column vector, which could be adjusted by multiple and rotation transformation to turn the matrix to a well-conditioned one. Then partition the corresponding matrix of the GM（1,1） power model in accordance with the column vector and regulate the matrix to a well-conditioned one by multiple and rotation transformation of vectors, which completely solve the instability problem of the GM（1,1） power model. Numerical results show that vector transformation is a new method in studying the stability problem of the GM（1,1） power model.展开更多
A simulation framework is proposed to evaluate the voltage stability of power systems incorporating wind power intermittency.Firstly，the power output modelings of three types of wind turbines are discussed.Secondly，...A simulation framework is proposed to evaluate the voltage stability of power systems incorporating wind power intermittency.Firstly，the power output modelings of three types of wind turbines are discussed.Secondly，the Jensen model is employed to simulate the wind farm with the wake effect.The Monte Carlo based technique is used to conduct the voltage stability evaluation incorporating the randomness of the wind speed based on the Weibull probability distribution.Thirdly，the relative sensitivity index（RSI）is calculated to identify weak buses during analysis.Finally，case studies with different simulation scenarios are carried out.Some statistical results involving weakness probability，expected value and variance of RSI as well as preliminary conclusions are drawn based on numerical simulation results.展开更多
作为抑制低频振荡最有效的手段之一,电力系统稳定器(power system stabilizer,PSS)在电力系统中得到了广泛的应用。现今国内最广泛采用的PSS是PSS2B,不过由于其自身结构问题,PSS2B对频率较低的区域间振荡模式抑制效果一般。新型多频段...作为抑制低频振荡最有效的手段之一,电力系统稳定器(power system stabilizer,PSS)在电力系统中得到了广泛的应用。现今国内最广泛采用的PSS是PSS2B,不过由于其自身结构问题,PSS2B对频率较低的区域间振荡模式抑制效果一般。新型多频段稳定器PSS4B有望解决这一问题,然而PSS4B的多参数多自由度给其参数整定带来了困难,提出了一种基于等高线控制器波特图(contoured controller bode,CCBode)的PSS4B稳定器迭代设计方法。PSS4B稳定器由带通滤波器和相位补偿器串联组成。使用空间搜索方法调整相位补偿器以确保PSS4B的相频特性被限制在可接受的范围内。CCBode曲线有助于调整带通滤波器的幅频特性,从而在较宽的频带范围内具有更好的稳定性能。对Kundur的四机两区系统的测试分析证明了该方法的有效性。展开更多
目的为了整体改善多机电力系统的功角和电压振荡特性,方法在包含电力系统稳定器(power system stabilizer,PSS)的多机系统中引入电力系统电压调节器(power system voltage regulator,PSVR),考虑电压振荡模式与功角振荡模式的相互影响,...目的为了整体改善多机电力系统的功角和电压振荡特性,方法在包含电力系统稳定器(power system stabilizer,PSS)的多机系统中引入电力系统电压调节器(power system voltage regulator,PSVR),考虑电压振荡模式与功角振荡模式的相互影响,合理整定PSVR参数。本文首先采用相频特性分析法和根轨迹法选择PSS与PSVR的参数初值;其次以控制器的增益系数和时间常数为控制变量,系统功角振荡模式和电压振荡模式的稳定性指标为优化目标,控制器参数取值范围为约束条件,建立多机系统PSS与PSVR的参数联合优化模型;最后采用非线性规划方法求解。结果通过实际算例分析,经过协调优化PSS与PSVR参数,系统的功角振荡模式和电压振荡模式得到了改善,二者阻尼比均能达到期望水平。在8机系统中,经过优化最小阻尼功角模式的阻尼比由0.0841变为0.1029,最小阻尼电压模式的阻尼比由0.0475变为0.0911;在某实际系统算例中,优化后功角、电压振荡模式中的最小阻尼模式也均能满足阈值要求。结论在包含PSS的多机系统中引入PSVR,利用本文所提多机系统PSS与PSVR参数联合优化模型,可以整体改善系统的功角和电压振荡特性。展开更多
抽水蓄能具有突出的能量密度和功率密度优势。借助其快速响应和灵活调节能力,能够有效平抑新能源出力随机波动,提高系统频率稳定性。针对抽水蓄能如何融入电力系统频率稳定控制问题,提出一种基于转速保护的变速抽蓄自适应综合惯量控制策...抽水蓄能具有突出的能量密度和功率密度优势。借助其快速响应和灵活调节能力,能够有效平抑新能源出力随机波动,提高系统频率稳定性。针对抽水蓄能如何融入电力系统频率稳定控制问题,提出一种基于转速保护的变速抽蓄自适应综合惯量控制策略,并采用优化思想对控制参数进行求解。在考虑短期频率变化率(rate of change of frequency,RoCoF)预测及变速抽蓄自适应综合惯量控制响应系统频率变化的基础上,对传统电力系统低频切泵策略进行改进,提出定速抽蓄自适应低频切泵控制策略。通过不同场景下的仿真验证,结果表明,将变速抽蓄自适应综合惯量调频控制策略与改进低频切泵策略相结合能够更好地适应高比例新能源电力系统,提升系统的频率调节性能。展开更多
文摘A novel technique for the optimal tuning of power system stabilizer (PSS) was proposed,by integrating the modified particle swarm optimization (MPSO) with the chaos (MPSOC).Firstly,a modification in the particle swarm optimization (PSO) was made by introducing passive congregation (PC).It helps each swarm member in receiving a multitude of information from other members and thus decreases the possibility of a failed attempt at detection or a meaningless search.Secondly,the MPSO and chaos were hybridized (MPSOC) to improve the global searching capability and prevent the premature convergence due to local minima.The robustness of the proposed PSS tuning technique was verified on a multi-machine power system under different operating conditions.The performance of the proposed MPSOC was compared to the MPSO,PSO and GA through eigenvalue analysis,nonlinear time-domain simulation and statistical tests.Eigenvalue analysis shows acceptable damping of the low-frequency modes and time domain simulations also show that the oscillations of synchronous machines can be rapidly damped for power systems with the proposed PSSs.The results show that the presented algorithm has a faster convergence rate with higher degree of accuracy than the GA,PSO and MPSO.
文摘为了演示和验证稳定器设计的就地相位补偿法在多机电力系统中的应用,介绍在多机电力系统中,就地补偿设计稳定器的2个应用实例。第1个实例是在多机电力系统中就地补偿设计电力系统稳定器（power system stabilizer,PSS）,阻尼电力系统局部模振荡。第2个实例是就地补偿设计附加在静态同步补偿器（static synchronous compensator,STATCOM）上的稳定器,抑制多机电力系统中的区域模振荡,并给出在一个16机电力系统中的应用计算和仿真结果。
文摘为解决电力系统稳定器(power system stabilizer,PSS)参数设置困难及传统的智能优化算法在寻优的过程中容易陷入局部最优,导致收敛速度下降的问题,因此文中采用混合策略改进SSA算法优化PSS参数。首先采用tent混沌映射来优化初始种群,提高种群多样性;采用柯西变异、正余弦策略和反向学习策略(opposition-based learning,OBL)来提升收敛速度;然后对6种测试函数进行寻优实验,将改进的SSA与PSO、GWO、SSA、SSSA优化结果对比,验证改进的SSA算法具有更好的收敛速度和稳定性;最后,将改进的SSA算法应用在单机无穷大系统及四机二区域系统的PSS参数优化中,与其他算法优化结果比较,验证改进的SSA在PSS参数优化方面的鲁棒性更好,收敛速度更快。
基金Project(51007042)supported by the National Natural Science Foundation of China
文摘Small signal instability may cause severe accidents for power system if it can not be dear correctly and timely. How to maintain power system stable under small signal disturbance is a big challenge for power system operators and dispatchers. Time delay existing in signal transmission process makes the problem more complex. Conventional eigenvalue analysis method neglects time delay influence and can not precisely describe power system dynamic behaviors. In this work, a modified small signal stability model considering time varying delay influence was constructed and a new time delay controller was proposed to stabilize power system under disturbance. By Lyapunov-Krasovskii function, the control law in the form of nonlinear matrix inequality （NLMI） was derived. Considering synthesis method limitation for time delay controller at present, both parameter adjustment method by using linear matrix inequality （LMI） solver and iteration searching method by solving nonlinear minimization problem were suggested to design the controller. Simulation tests were carried out on synchronous-machine infinite-bus power system. Satisfactory test results verify the correctness of the proposed model and the feasibility of the stabilization approach.
文摘On the basis of the theoretical analysis of a single-machine infinite-bus （SMIB）, using the modified linearized Phil- lips-Heffron model installed with unified power flow controller （UPFC）, the potential of the UPFC supplementary controller to enhance the dynamic stability of a power system is evaluated by measuring the electromechanical controllability through singular value decomposition （SVD） analysis. This controller is tuned to simultaneously shift the undamped electromeehanical modes to a prescribed zone in the s-plane. The problem of robust UPFC based damping controller is formulated as an optimization problem according to the eigenvalue-based multi-objective function comprising the damping factor, and the damping ratio of the undamped electromechanical modes to be solved using gravitational search algorithm （GSA） that has a strong ability to find the most optimistic results. The different loading conditions are simulated on a SMIB system and the rotor speed deviation, internal voltage deviation, DC voltage deviation and electrical power deviation responses are studied with the effect of this flexible AC transmission systems （FACTS） controller. The results reveal that the tuned GSA based UPFC controller using the proposed multi-objective function has an excellent capability in damping power system with low frequency oscillations and greatly enhances the dynamic stability of the power systems.
基金Projects(60425310,60974026) supported by the National Natural Science Foundation of ChinaProject(200805330004) supported by the Doctor Subject Foundation of China+1 种基金Projects(NCET-06-0679) supported by Program for New Century Excellent Talents in UniversityProject(08JJ1010) supported by the Natural Science Foundation of Hunan Province,China
文摘In order to analyze power system stability in environment of WAMS(wide area measurement system),a new steady state stability model with time-varying delay was proposed for power system.The factors of exciter and power system stabilizer with delay were introduced into analytical model.To decrease conservativeness of stability analysis,an improved Lyapunov-Krasovskii functional was constructed,and then a new delay-dependent steady state stability criterion for power system,which overcomes the disadvantages of eigenvalue computation method,was derived.The proposed model and criterion were tested on synchronous-machine infinite-bus power system.The test results demonstrate that Lyapunov-Krasovskii functional based power system stability analysis method is applicable and effective in the analysis of time delay power system stability.
基金supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China(20120143110001)the General Education Program Requirements in the Humanities and Social Sciences of China(11YJC630155)the Youth Foundation of Hubei Province of China(Q20121203)
文摘The morbidity problem of the GM（1,1） power model in parameter identification is discussed by using multiple and rotation transformation of vectors. Firstly we consider the morbidity problem of the special matrix and prove that the condition number of the coefficient matrix is determined by the ratio of lengths and the included angle of the column vector, which could be adjusted by multiple and rotation transformation to turn the matrix to a well-conditioned one. Then partition the corresponding matrix of the GM（1,1） power model in accordance with the column vector and regulate the matrix to a well-conditioned one by multiple and rotation transformation of vectors, which completely solve the instability problem of the GM（1,1） power model. Numerical results show that vector transformation is a new method in studying the stability problem of the GM（1,1） power model.
基金This work is supported by National Natural Science Foundation of China （No. 50977051 ） and Research Project of Science and Technology from Shenzhen Development and Innovation Committee （No. ZDSY20120619141142918）.
文摘A simulation framework is proposed to evaluate the voltage stability of power systems incorporating wind power intermittency.Firstly，the power output modelings of three types of wind turbines are discussed.Secondly，the Jensen model is employed to simulate the wind farm with the wake effect.The Monte Carlo based technique is used to conduct the voltage stability evaluation incorporating the randomness of the wind speed based on the Weibull probability distribution.Thirdly，the relative sensitivity index（RSI）is calculated to identify weak buses during analysis.Finally，case studies with different simulation scenarios are carried out.Some statistical results involving weakness probability，expected value and variance of RSI as well as preliminary conclusions are drawn based on numerical simulation results.
文摘作为抑制低频振荡最有效的手段之一,电力系统稳定器(power system stabilizer,PSS)在电力系统中得到了广泛的应用。现今国内最广泛采用的PSS是PSS2B,不过由于其自身结构问题,PSS2B对频率较低的区域间振荡模式抑制效果一般。新型多频段稳定器PSS4B有望解决这一问题,然而PSS4B的多参数多自由度给其参数整定带来了困难,提出了一种基于等高线控制器波特图(contoured controller bode,CCBode)的PSS4B稳定器迭代设计方法。PSS4B稳定器由带通滤波器和相位补偿器串联组成。使用空间搜索方法调整相位补偿器以确保PSS4B的相频特性被限制在可接受的范围内。CCBode曲线有助于调整带通滤波器的幅频特性,从而在较宽的频带范围内具有更好的稳定性能。对Kundur的四机两区系统的测试分析证明了该方法的有效性。
基金Supported by National Natural Science Foundation of China（60774010 10971256） Natural Science Foundation of Jiangsu Province（BK2009083）+1 种基金 Program for Fundamental Research of Natural Sciences in Universities of Jiangsu Province（07KJB510114） Shandong Provincial Natural Science Foundation of China（ZR2009GM008 ZR2009AL014）
文摘目的为了整体改善多机电力系统的功角和电压振荡特性,方法在包含电力系统稳定器(power system stabilizer,PSS)的多机系统中引入电力系统电压调节器(power system voltage regulator,PSVR),考虑电压振荡模式与功角振荡模式的相互影响,合理整定PSVR参数。本文首先采用相频特性分析法和根轨迹法选择PSS与PSVR的参数初值;其次以控制器的增益系数和时间常数为控制变量,系统功角振荡模式和电压振荡模式的稳定性指标为优化目标,控制器参数取值范围为约束条件,建立多机系统PSS与PSVR的参数联合优化模型;最后采用非线性规划方法求解。结果通过实际算例分析,经过协调优化PSS与PSVR参数,系统的功角振荡模式和电压振荡模式得到了改善,二者阻尼比均能达到期望水平。在8机系统中,经过优化最小阻尼功角模式的阻尼比由0.0841变为0.1029,最小阻尼电压模式的阻尼比由0.0475变为0.0911;在某实际系统算例中,优化后功角、电压振荡模式中的最小阻尼模式也均能满足阈值要求。结论在包含PSS的多机系统中引入PSVR,利用本文所提多机系统PSS与PSVR参数联合优化模型,可以整体改善系统的功角和电压振荡特性。
文摘抽水蓄能具有突出的能量密度和功率密度优势。借助其快速响应和灵活调节能力,能够有效平抑新能源出力随机波动,提高系统频率稳定性。针对抽水蓄能如何融入电力系统频率稳定控制问题,提出一种基于转速保护的变速抽蓄自适应综合惯量控制策略,并采用优化思想对控制参数进行求解。在考虑短期频率变化率(rate of change of frequency,RoCoF)预测及变速抽蓄自适应综合惯量控制响应系统频率变化的基础上,对传统电力系统低频切泵策略进行改进,提出定速抽蓄自适应低频切泵控制策略。通过不同场景下的仿真验证,结果表明,将变速抽蓄自适应综合惯量调频控制策略与改进低频切泵策略相结合能够更好地适应高比例新能源电力系统,提升系统的频率调节性能。
