以统一潮流控制器(unified power flow controller,UPFC)为代表的灵活交流输电技术(flexible AC transmission system,FACTS)可实现传输功率的合理分布、优化系统资源,提高系统的稳定性和可靠性。该文基于内点优化方法,提出计及UPFC的...以统一潮流控制器(unified power flow controller,UPFC)为代表的灵活交流输电技术(flexible AC transmission system,FACTS)可实现传输功率的合理分布、优化系统资源,提高系统的稳定性和可靠性。该文基于内点优化方法,提出计及UPFC的无功优化模型,以系统有功网损最小为目标函数,采用UPFC电压源模型,将其作用等效为一系列电压和功率的约束,直接放到内点法的约束中,在不同的负荷运行方式下进行优化分析。在IEEE-30节点系统测试中发现,引入UPFC后系数矩阵的维数会有所增加,但不会影响其收敛性。算例就系统网损和电压指标对装设UPFC前后进行比较,并给出最优控制方案下UPFC的参数值。结果表明该方法是可行的、有效的,取得很好的效果。展开更多
针对带有TCSC(Thyristor Controlled Series Compensator)的单机无穷大电力系统,提出一种新的TCSC自适应非线性控制Backstepping方法.该方法不仅保留了系统的非线性特性和对未知参数的实时在线估计,而且突破了经典的确定性等价性原理来...针对带有TCSC(Thyristor Controlled Series Compensator)的单机无穷大电力系统,提出一种新的TCSC自适应非线性控制Backstepping方法.该方法不仅保留了系统的非线性特性和对未知参数的实时在线估计,而且突破了经典的确定性等价性原理来设计参数估计器和动态反馈控制器.仿真结果表明,与基于传统自适应Backstep-p ing得到的控制设计相比较,这种新方法在系统响应和自适应速度方面具有更优越的性能,从而为工程应用提供了一种有效的选择.展开更多
Forced oscillations(FOs), or low-frequency oscillations(LFOs) caused by periodic, continuous, small power disturbances, threaten the security and stability of power systems.Flexible AC transmission system(FACTS)device...Forced oscillations(FOs), or low-frequency oscillations(LFOs) caused by periodic, continuous, small power disturbances, threaten the security and stability of power systems.Flexible AC transmission system(FACTS)devices can effectively mitigate LFOs via stability control.We propose a novel method that mitigates FOs by shifting the resonant frequency.Based on the features of the linearized swing equation of a generator, a resonant frequency shift can be achieved by controlling the synchronous torque coefficient using a unified power flow controller(UPFC).Because of the resonance mechanism, the steady-state response of an FO can be effectively mitigated when the resonant frequency changes from the original one, which was close to the disturbance frequency.The principle is that a change in resonant frequency affects the resonance condition.Simulations are conducted in a single-machine infinite-bus(SMIB) system, and the simulation results verify that the method is straightforward to implement and can significantly mitigate FOs.The controller robustness when the resonant frequency is not accurately estimated is also analyzed in the simulations.展开更多
统一潮流控制器(Unified power flow Controller,UPFC)是目前最先进的柔性交流输电系统技术。分析UPFC工作在潮流控制时的有功/无功功率平衡,提出一种改进实时功率协调控制方法,通过在UPFC并联侧变流器的有功、无功控制环路中增加改进...统一潮流控制器(Unified power flow Controller,UPFC)是目前最先进的柔性交流输电系统技术。分析UPFC工作在潮流控制时的有功/无功功率平衡,提出一种改进实时功率协调控制方法,通过在UPFC并联侧变流器的有功、无功控制环路中增加改进实时前馈电流,减小动态过程中不平衡功率引起的过电压。基于RT-LAB的硬件在环仿真结果表明,相比现有常规协调控制方法,所提方法减小了潮流控制和系统故障时送端电压和直流电容电压的过电压,提高了系统故障后恢复速度。展开更多
In order to facilitate the electricity market operation and trade in the restructured environment, ample transmission capability should be provided to satisfy the demand of increasing power transactions. The conflict ...In order to facilitate the electricity market operation and trade in the restructured environment, ample transmission capability should be provided to satisfy the demand of increasing power transactions. The conflict of this requirement and the restrictions on the transmission expansion in the restructured electrical market has motivated the development of methodologies to enhance the Available Transfer Capability (ATC) of the existing transmission grids. The insertion of FACTS devices in electrical systems seems to be a promising strategy to enhance ATC. In this paper, the viability and technical merits of boosting ATC using Thyristor Controlled Series Compensator (TCSC) is being analyzed. The work has been carried out on IEEE 30 bus and IEEE 118 bus systems. Bilateral and multilateral transactions are considered. Particle Swarm Optimization (PSO) algorithm and Genetic Algorithm (GA) are employed to obtain the optimal settings of TCSC.展开更多
文摘以统一潮流控制器(unified power flow controller,UPFC)为代表的灵活交流输电技术(flexible AC transmission system,FACTS)可实现传输功率的合理分布、优化系统资源,提高系统的稳定性和可靠性。该文基于内点优化方法,提出计及UPFC的无功优化模型,以系统有功网损最小为目标函数,采用UPFC电压源模型,将其作用等效为一系列电压和功率的约束,直接放到内点法的约束中,在不同的负荷运行方式下进行优化分析。在IEEE-30节点系统测试中发现,引入UPFC后系数矩阵的维数会有所增加,但不会影响其收敛性。算例就系统网损和电压指标对装设UPFC前后进行比较,并给出最优控制方案下UPFC的参数值。结果表明该方法是可行的、有效的,取得很好的效果。
文摘针对带有TCSC(Thyristor Controlled Series Compensator)的单机无穷大电力系统,提出一种新的TCSC自适应非线性控制Backstepping方法.该方法不仅保留了系统的非线性特性和对未知参数的实时在线估计,而且突破了经典的确定性等价性原理来设计参数估计器和动态反馈控制器.仿真结果表明,与基于传统自适应Backstep-p ing得到的控制设计相比较,这种新方法在系统响应和自适应速度方面具有更优越的性能,从而为工程应用提供了一种有效的选择.
基金supported by National Natural Science Foundation of China (No.51577032)State Grid Corporation of China (No.5210K017000C)
文摘Forced oscillations(FOs), or low-frequency oscillations(LFOs) caused by periodic, continuous, small power disturbances, threaten the security and stability of power systems.Flexible AC transmission system(FACTS)devices can effectively mitigate LFOs via stability control.We propose a novel method that mitigates FOs by shifting the resonant frequency.Based on the features of the linearized swing equation of a generator, a resonant frequency shift can be achieved by controlling the synchronous torque coefficient using a unified power flow controller(UPFC).Because of the resonance mechanism, the steady-state response of an FO can be effectively mitigated when the resonant frequency changes from the original one, which was close to the disturbance frequency.The principle is that a change in resonant frequency affects the resonance condition.Simulations are conducted in a single-machine infinite-bus(SMIB) system, and the simulation results verify that the method is straightforward to implement and can significantly mitigate FOs.The controller robustness when the resonant frequency is not accurately estimated is also analyzed in the simulations.
文摘统一潮流控制器(Unified power flow Controller,UPFC)是目前最先进的柔性交流输电系统技术。分析UPFC工作在潮流控制时的有功/无功功率平衡,提出一种改进实时功率协调控制方法,通过在UPFC并联侧变流器的有功、无功控制环路中增加改进实时前馈电流,减小动态过程中不平衡功率引起的过电压。基于RT-LAB的硬件在环仿真结果表明,相比现有常规协调控制方法,所提方法减小了潮流控制和系统故障时送端电压和直流电容电压的过电压,提高了系统故障后恢复速度。
文摘In order to facilitate the electricity market operation and trade in the restructured environment, ample transmission capability should be provided to satisfy the demand of increasing power transactions. The conflict of this requirement and the restrictions on the transmission expansion in the restructured electrical market has motivated the development of methodologies to enhance the Available Transfer Capability (ATC) of the existing transmission grids. The insertion of FACTS devices in electrical systems seems to be a promising strategy to enhance ATC. In this paper, the viability and technical merits of boosting ATC using Thyristor Controlled Series Compensator (TCSC) is being analyzed. The work has been carried out on IEEE 30 bus and IEEE 118 bus systems. Bilateral and multilateral transactions are considered. Particle Swarm Optimization (PSO) algorithm and Genetic Algorithm (GA) are employed to obtain the optimal settings of TCSC.
