Essentially, it is significant to supply the consumer with reliable and sufficient power. Since, power quality is measured by the consistency in frequency and power flow between control areas. Thus, in a power system ...Essentially, it is significant to supply the consumer with reliable and sufficient power. Since, power quality is measured by the consistency in frequency and power flow between control areas. Thus, in a power system operation and control,automatic generation control(AGC) plays a crucial role. In this paper, multi-area(Five areas: area 1, area 2, area 3, area 4 and area 5) reheat thermal power systems are considered with proportional-integral-derivative(PID) controller as a supplementary controller. Each area in the investigated power system is equipped with appropriate governor unit, turbine with reheater unit, generator and speed regulator unit. The PID controller parameters are optimized by considering nature bio-inspired firefly algorithm(FFA). The experimental results demonstrated the comparison of the proposed system performance(FFA-PID)with optimized PID controller based genetic algorithm(GAPID) and particle swarm optimization(PSO) technique(PSOPID) for the same investigated power system. The results proved the efficiency of employing the integral time absolute error(ITAE) cost function with one percent step load perturbation(1 % SLP) in area 1. The proposed system based FFA achieved the least settling time compared to using the GA or the PSO algorithms, while, it attained good results with respect to the peak overshoot/undershoot. In addition, the FFA performance is improved with the increased number of iterations which outperformed the other optimization algorithms based controller.展开更多
A type of high-order integral observers for matrix second-order linear systems is proposed on the basis of generalized eigenstructure assignment via unified parametric approaches. Through establishing two general para...A type of high-order integral observers for matrix second-order linear systems is proposed on the basis of generalized eigenstructure assignment via unified parametric approaches. Through establishing two general parametric solutions to this type of generalized matrix second-order Sylvester matrix equations, two unified complete parametric methods for the proposed observer design problem are presented. Both methods give simple complete parametric expressions for the observer gain matrices. The first one mainly depends on a series of singular value decompositions, and is thus numerically simple and reliable; the second one utilizes the fight factorization of the system, and allows eigenvalues of the error system to be set undetermined and sought via certain optimization procedures. A spring-mass-dashpot system is utilized to illustrate the design procedure and show the effect of the proposed approach.展开更多
Fast and accurate monitoring of the phase,amplitude,and frequency of the grid voltage is essential for single-phase grid-connected converters.The presence of DC offset in the grid voltage is detrimental to not only gr...Fast and accurate monitoring of the phase,amplitude,and frequency of the grid voltage is essential for single-phase grid-connected converters.The presence of DC offset in the grid voltage is detrimental to not only grid synchronization but also the closed-loop stability of the grid-connected converters.In this paper,a new synchronization method to mitigate the effect of DC offset is presented using arbitrarily delayed signal cancelation(ADSC)in a second-order generalized integrator(SOGI)phase-locked loop(PLL).A frequency-fixed SOGI-based PLL(FFSOGI-PLL)is adopted to ensure better stability and to reduce the complexity compared with other SOGI-based PLLs.A small-signal model of the proposed PLL is derived for the systematic design of proportional-integral(PI)controller gains.The effects of frequency variation and ADSC on the proposed PLL are considered,and correction methods are adopted to accurately estimate grid information.The simulation results are presented,along with comparisons to other single-phase PLLs in terms of settling time,peak frequency,and phase error to validate the proposed PLL.The dynamic performance of the proposed PLL is also experimentally validated.Overall,the proposed PLL has the fastest transient response and better dynamic performance than the other PLLs for almost all performance indices,offering an improved solution for precise grid synchronization in single-phase applications.展开更多
Present day power scenarios demand a high quality uninterrupted power supply and needs environmental issues to be addressed. Both concerns can be dealt with by the introduction of the renewable sources to the existing...Present day power scenarios demand a high quality uninterrupted power supply and needs environmental issues to be addressed. Both concerns can be dealt with by the introduction of the renewable sources to the existing power system. Thus, automatic generation control(AGC) with diverse renewable sources and a modified-cascaded controller are presented in the paper.Also, a new hybrid scheme of the improved teaching learning based optimization-differential evolution(hITLBO-DE) algorithm is applied for providing optimization of controller parameters. A study of the system with a technique such as TLBO applied to a proportional integral derivative(PID), integral double derivative(IDD) and PIDD is compared to hITLBO-DE tuned cascaded controller with dynamic load change.The suggested methodology has been extensively applied to a 2-area system with a diverse source power system with various operation time non-linearities such as dead-band of, generation rate constraint and reheat thermal units. The multi-area system with reheat thermal plants, hydel plants and a unit of a wind-diesel combination is tested with the cascaded controller scheme with a different controller setting for each area. The variation of the load is taken within 1% to 5% of the connected load and robustness analysis is shown by modifying essential factors simultaneously by± 30%. Finally, the proposed scheme of controller and optimization technique is also tested with a 5-equal area thermal system with non-linearities. The simulation results demonstrate the superiority of the proposed controller and algorithm under a dynamically changing load.展开更多
In order to solve the ambiguity problems in the semantic context (structure, granularity or scale) emerging in the process of ontology integration application, this paper analyzes the essential characters of context...In order to solve the ambiguity problems in the semantic context (structure, granularity or scale) emerging in the process of ontology integration application, this paper analyzes the essential characters of context structure, proposes a novel semantic context generating algorithm, which is implemented over VO-Editor(visual ontology editor), from the satisfiability-based point of view, and proves that the context entity generated by this algorithm is smallest in scale and unique. It offers a feasible means for developers to handle context problems for ontology integration application.展开更多
为促进清洁能源消纳及多能耦合系统灵活运行,降低源、荷不确定性对系统的影响,构建包含光热电站的风光电热氢综合能源系统(wind-photovoltaic-electric-heat-hydrogen integrated energy system,WPEHHIES),提出一种鲁棒性可调的空间多...为促进清洁能源消纳及多能耦合系统灵活运行,降低源、荷不确定性对系统的影响,构建包含光热电站的风光电热氢综合能源系统(wind-photovoltaic-electric-heat-hydrogen integrated energy system,WPEHHIES),提出一种鲁棒性可调的空间多面体不确定集两阶段鲁棒优化方法。基于列与约束生成(column-andconstraint generation,C&CG)算法将两阶段三层min-max-min鲁棒优化模型分解为一层min主问题与两层max-min子问题,通过强对偶原理将双层子问题结构简化处理;由子问题与主问题的交替求解,进而得到原问题的最优解。最后,通过算例分析验证所构建模型和求解算法的有效性及多能耦合系统出力的灵活性。展开更多
为了解决使用第三方软件搭建远程实验室可能带来的依赖性强、灵活性差、效率低以及数据与隐私泄露问题,实现技术自主可控,以网络化控制系统实验室(NCSLab)的前端软件和硬件为基础,开发了一款面向远程实验室仿真与算法生成的一体化软件M2...为了解决使用第三方软件搭建远程实验室可能带来的依赖性强、灵活性差、效率低以及数据与隐私泄露问题,实现技术自主可控,以网络化控制系统实验室(NCSLab)的前端软件和硬件为基础,开发了一款面向远程实验室仿真与算法生成的一体化软件M2PLink(mathematics to practice link)。研究了从控制框图到控制代码的映射关系,并对各个控制模块进行了模块化设计。通过分析模块之间的依赖关系及算法结构,建立算法的输出链,并根据微分求解算法设计了多种求解器,最终基于制定的代码生成策略生成对应的控制代码。离线仿真实验和实体实验系统测试结果表明,M2PLink的计算精度满足要求,生成的代码适用于实体控制实验且系统效率得到了大幅度提升。目前,M2PLink已经部署在网络化控制系统实验室中,用于自动化专业实验教学,并且取得了较好的教学效果。展开更多
“双碳”背景下,多综合能源微网(integrated energy microgrid,IEM)系统优化运行过程中面临着协同管理、新能源出力随机波动、负荷功率不确定性以及信息隐私保护等诸多挑战。计及源荷不确定性,提出一种基于纳什谈判的多IEM系统两阶段博...“双碳”背景下,多综合能源微网(integrated energy microgrid,IEM)系统优化运行过程中面临着协同管理、新能源出力随机波动、负荷功率不确定性以及信息隐私保护等诸多挑战。计及源荷不确定性,提出一种基于纳什谈判的多IEM系统两阶段博弈策略。首先,针对源荷不确定性构建源荷不确定集合,建立多IEM系统的源-荷两阶段鲁棒优化调度模型;其次,充分挖掘IEM成员间的潜在合作关系,基于纳什谈判理论构建多IEM两阶段鲁棒博弈模型,并将原问题等效为多IEM系统效益最大化和支付效益最大化两个子问题,以保证多IEM系统合作收益的公平分配;最后,为保护各主体隐私,采用列约束生成算法结合交替方向乘子法(alternating direction multiplier method,ADMM)高效求解所构建的模型。算例结果表明,所提策略能够实现多IEM系统电、热资源的优化配置,系统总运行成本降低了5.16%,风光消纳率达到80%以上,并提高了系统应对不确定性风险的能力。展开更多
文摘Essentially, it is significant to supply the consumer with reliable and sufficient power. Since, power quality is measured by the consistency in frequency and power flow between control areas. Thus, in a power system operation and control,automatic generation control(AGC) plays a crucial role. In this paper, multi-area(Five areas: area 1, area 2, area 3, area 4 and area 5) reheat thermal power systems are considered with proportional-integral-derivative(PID) controller as a supplementary controller. Each area in the investigated power system is equipped with appropriate governor unit, turbine with reheater unit, generator and speed regulator unit. The PID controller parameters are optimized by considering nature bio-inspired firefly algorithm(FFA). The experimental results demonstrated the comparison of the proposed system performance(FFA-PID)with optimized PID controller based genetic algorithm(GAPID) and particle swarm optimization(PSO) technique(PSOPID) for the same investigated power system. The results proved the efficiency of employing the integral time absolute error(ITAE) cost function with one percent step load perturbation(1 % SLP) in area 1. The proposed system based FFA achieved the least settling time compared to using the GA or the PSO algorithms, while, it attained good results with respect to the peak overshoot/undershoot. In addition, the FFA performance is improved with the increased number of iterations which outperformed the other optimization algorithms based controller.
基金This work was supported by the Chinese National Natural Science Foundation ( No. 69925308).
文摘A type of high-order integral observers for matrix second-order linear systems is proposed on the basis of generalized eigenstructure assignment via unified parametric approaches. Through establishing two general parametric solutions to this type of generalized matrix second-order Sylvester matrix equations, two unified complete parametric methods for the proposed observer design problem are presented. Both methods give simple complete parametric expressions for the observer gain matrices. The first one mainly depends on a series of singular value decompositions, and is thus numerically simple and reliable; the second one utilizes the fight factorization of the system, and allows eigenvalues of the error system to be set undetermined and sought via certain optimization procedures. A spring-mass-dashpot system is utilized to illustrate the design procedure and show the effect of the proposed approach.
基金supported by the Deanship of Research at Jordan University of Science and Technology (Grant number:20210333).
文摘Fast and accurate monitoring of the phase,amplitude,and frequency of the grid voltage is essential for single-phase grid-connected converters.The presence of DC offset in the grid voltage is detrimental to not only grid synchronization but also the closed-loop stability of the grid-connected converters.In this paper,a new synchronization method to mitigate the effect of DC offset is presented using arbitrarily delayed signal cancelation(ADSC)in a second-order generalized integrator(SOGI)phase-locked loop(PLL).A frequency-fixed SOGI-based PLL(FFSOGI-PLL)is adopted to ensure better stability and to reduce the complexity compared with other SOGI-based PLLs.A small-signal model of the proposed PLL is derived for the systematic design of proportional-integral(PI)controller gains.The effects of frequency variation and ADSC on the proposed PLL are considered,and correction methods are adopted to accurately estimate grid information.The simulation results are presented,along with comparisons to other single-phase PLLs in terms of settling time,peak frequency,and phase error to validate the proposed PLL.The dynamic performance of the proposed PLL is also experimentally validated.Overall,the proposed PLL has the fastest transient response and better dynamic performance than the other PLLs for almost all performance indices,offering an improved solution for precise grid synchronization in single-phase applications.
文摘Present day power scenarios demand a high quality uninterrupted power supply and needs environmental issues to be addressed. Both concerns can be dealt with by the introduction of the renewable sources to the existing power system. Thus, automatic generation control(AGC) with diverse renewable sources and a modified-cascaded controller are presented in the paper.Also, a new hybrid scheme of the improved teaching learning based optimization-differential evolution(hITLBO-DE) algorithm is applied for providing optimization of controller parameters. A study of the system with a technique such as TLBO applied to a proportional integral derivative(PID), integral double derivative(IDD) and PIDD is compared to hITLBO-DE tuned cascaded controller with dynamic load change.The suggested methodology has been extensively applied to a 2-area system with a diverse source power system with various operation time non-linearities such as dead-band of, generation rate constraint and reheat thermal units. The multi-area system with reheat thermal plants, hydel plants and a unit of a wind-diesel combination is tested with the cascaded controller scheme with a different controller setting for each area. The variation of the load is taken within 1% to 5% of the connected load and robustness analysis is shown by modifying essential factors simultaneously by± 30%. Finally, the proposed scheme of controller and optimization technique is also tested with a 5-equal area thermal system with non-linearities. The simulation results demonstrate the superiority of the proposed controller and algorithm under a dynamically changing load.
基金the National Natural Science Foundation of China ( 90604005)
文摘In order to solve the ambiguity problems in the semantic context (structure, granularity or scale) emerging in the process of ontology integration application, this paper analyzes the essential characters of context structure, proposes a novel semantic context generating algorithm, which is implemented over VO-Editor(visual ontology editor), from the satisfiability-based point of view, and proves that the context entity generated by this algorithm is smallest in scale and unique. It offers a feasible means for developers to handle context problems for ontology integration application.
文摘为促进清洁能源消纳及多能耦合系统灵活运行,降低源、荷不确定性对系统的影响,构建包含光热电站的风光电热氢综合能源系统(wind-photovoltaic-electric-heat-hydrogen integrated energy system,WPEHHIES),提出一种鲁棒性可调的空间多面体不确定集两阶段鲁棒优化方法。基于列与约束生成(column-andconstraint generation,C&CG)算法将两阶段三层min-max-min鲁棒优化模型分解为一层min主问题与两层max-min子问题,通过强对偶原理将双层子问题结构简化处理;由子问题与主问题的交替求解,进而得到原问题的最优解。最后,通过算例分析验证所构建模型和求解算法的有效性及多能耦合系统出力的灵活性。
文摘为了解决使用第三方软件搭建远程实验室可能带来的依赖性强、灵活性差、效率低以及数据与隐私泄露问题,实现技术自主可控,以网络化控制系统实验室(NCSLab)的前端软件和硬件为基础,开发了一款面向远程实验室仿真与算法生成的一体化软件M2PLink(mathematics to practice link)。研究了从控制框图到控制代码的映射关系,并对各个控制模块进行了模块化设计。通过分析模块之间的依赖关系及算法结构,建立算法的输出链,并根据微分求解算法设计了多种求解器,最终基于制定的代码生成策略生成对应的控制代码。离线仿真实验和实体实验系统测试结果表明,M2PLink的计算精度满足要求,生成的代码适用于实体控制实验且系统效率得到了大幅度提升。目前,M2PLink已经部署在网络化控制系统实验室中,用于自动化专业实验教学,并且取得了较好的教学效果。
文摘“双碳”背景下,多综合能源微网(integrated energy microgrid,IEM)系统优化运行过程中面临着协同管理、新能源出力随机波动、负荷功率不确定性以及信息隐私保护等诸多挑战。计及源荷不确定性,提出一种基于纳什谈判的多IEM系统两阶段博弈策略。首先,针对源荷不确定性构建源荷不确定集合,建立多IEM系统的源-荷两阶段鲁棒优化调度模型;其次,充分挖掘IEM成员间的潜在合作关系,基于纳什谈判理论构建多IEM两阶段鲁棒博弈模型,并将原问题等效为多IEM系统效益最大化和支付效益最大化两个子问题,以保证多IEM系统合作收益的公平分配;最后,为保护各主体隐私,采用列约束生成算法结合交替方向乘子法(alternating direction multiplier method,ADMM)高效求解所构建的模型。算例结果表明,所提策略能够实现多IEM系统电、热资源的优化配置,系统总运行成本降低了5.16%,风光消纳率达到80%以上,并提高了系统应对不确定性风险的能力。