发电机组的一次调频控制回路中由于数字电液调节系统与机械液压调节系统的并存,使得本应发挥高灵敏度作用的 DEH 调节系统中设置了和机械液压机组相同的调频死区。考虑到调频死区这一非线性环节的存在使二次调频回路中控制器的受控对象...发电机组的一次调频控制回路中由于数字电液调节系统与机械液压调节系统的并存,使得本应发挥高灵敏度作用的 DEH 调节系统中设置了和机械液压机组相同的调频死区。考虑到调频死区这一非线性环节的存在使二次调频回路中控制器的受控对象发生了改变,因此需要用相应的非线性控制的方法来选择二次调频控制回路中的 PI 控制器的参数。该文研究了调频死区对二次调频回路中的 PI 控制器的受控对象特性的影响,用 Popov 稳定判据作为选择 PI 参数使系统稳定的数学工具,讨论了 PI 参数的变化对系统频率控制质量的影响。展开更多
为了消除调速器死区非线性对系统的影响和保证系统稳定,针对存在调速器死区的负荷频率控制(load frequency control,LFC)系统,采用了自抗扰控制(active disturbance rejection control,ADRC)方法,并通过描述函数法验证控制方法的有效性...为了消除调速器死区非线性对系统的影响和保证系统稳定,针对存在调速器死区的负荷频率控制(load frequency control,LFC)系统,采用了自抗扰控制(active disturbance rejection control,ADRC)方法,并通过描述函数法验证控制方法的有效性。提出死区线性化方法,并采用了广义自抗扰控制(generalized active disturbance rejection control,GADRC)方法。为能有效地消除死区非线性,提出了一种误差补偿策略。仿真结果显示,提出的误差补偿策略能有效地消除死区非线性,保证了系统的控制性能。提出通过描述函数法获得补偿系数的取值范围也是可行。展开更多
The cost of Energy Storage System(ESS)for frequency regulation is difficult to calculate due to battery’s degradation when an ESS is in grid-connected operation.To solve this problem,the influence mechanism of actual...The cost of Energy Storage System(ESS)for frequency regulation is difficult to calculate due to battery’s degradation when an ESS is in grid-connected operation.To solve this problem,the influence mechanism of actual operating conditions on the life degradation of Li-ion battery energy storage is analyzed.A control strategy of Li-ion ESS participating in grid frequency regulation is constructed and a cost accounting model for frequency regulation considering the effect of battery life degradation is established.The estimated operating life and annual average cost of the Li-ion ESS under different dead bands and SOC set-points are calculated.The case studies show that the estimated operating life of the Li-ion ESS under the actual operating condition differs significantly from the nominal life provided by the manufacturer under the standard condition and the full discharge mode.This paper provides an accurate costing method for the ESS participating in grid frequency regulation to help the promotion of the ESS to participate in the ancillary service market.展开更多
In this work,chaos game optimization(CGO),a robust optimization approach,is employed for efficient design of a novel cascade controller for four test systems with interconnected power systems(IPSs)to tackle load-frequ...In this work,chaos game optimization(CGO),a robust optimization approach,is employed for efficient design of a novel cascade controller for four test systems with interconnected power systems(IPSs)to tackle load-frequency con-trol(LFC)difficulties.The CGO method is based on chaos theory principles,in which the structure of fractals is seen via the chaotic game principle and the fractals’self-similarity characteristics are considered.CGO is applied in LFC studies as a novel application,which reveals further research gaps to be filled.For practical implementation,it is also highly desirable to keep the controller structure simple.Accordingly,in this paper,a CGO-based controller of fractional-order(FO)proportional-integral-derivative-FO proportional-integral(FOPID-FOPI)controller is proposed,and the integral time multiplied absolute error performance function is used.Initially,the proposed CGO-based FOPID-FOPI controller is tested with and without the nonlinearity of the governor dead band for a two-area two-source model of a non-reheat unit.This is a common test system in the literature.A two-area multi-unit system with reheater-hydro-gas in both areas is implemented.To further generalize the advantages of the proposed scheme,a model of a three-area hydrothermal IPS including generation rate constraint nonlinearity is employed.For each test system,comparisons with relevant existing studies are performed.These demonstrate the superiority of the proposed scheme in reducing settling time,and frequency and tie-line power deviations.展开更多
文摘发电机组的一次调频控制回路中由于数字电液调节系统与机械液压调节系统的并存,使得本应发挥高灵敏度作用的 DEH 调节系统中设置了和机械液压机组相同的调频死区。考虑到调频死区这一非线性环节的存在使二次调频回路中控制器的受控对象发生了改变,因此需要用相应的非线性控制的方法来选择二次调频控制回路中的 PI 控制器的参数。该文研究了调频死区对二次调频回路中的 PI 控制器的受控对象特性的影响,用 Popov 稳定判据作为选择 PI 参数使系统稳定的数学工具,讨论了 PI 参数的变化对系统频率控制质量的影响。
文摘为了消除调速器死区非线性对系统的影响和保证系统稳定,针对存在调速器死区的负荷频率控制(load frequency control,LFC)系统,采用了自抗扰控制(active disturbance rejection control,ADRC)方法,并通过描述函数法验证控制方法的有效性。提出死区线性化方法,并采用了广义自抗扰控制(generalized active disturbance rejection control,GADRC)方法。为能有效地消除死区非线性,提出了一种误差补偿策略。仿真结果显示,提出的误差补偿策略能有效地消除死区非线性,保证了系统的控制性能。提出通过描述函数法获得补偿系数的取值范围也是可行。
基金This work is supported in part by Industrial Innovation of Jilin Province Development and Reform Commission(2017C017-2)Science&Technology Project of SGCC(Key technology and application of super large capac-ity battery energy storage system),and Jilin Provincial“13th Five-Year Plan”Science and Technology Project([2016]88).
文摘The cost of Energy Storage System(ESS)for frequency regulation is difficult to calculate due to battery’s degradation when an ESS is in grid-connected operation.To solve this problem,the influence mechanism of actual operating conditions on the life degradation of Li-ion battery energy storage is analyzed.A control strategy of Li-ion ESS participating in grid frequency regulation is constructed and a cost accounting model for frequency regulation considering the effect of battery life degradation is established.The estimated operating life and annual average cost of the Li-ion ESS under different dead bands and SOC set-points are calculated.The case studies show that the estimated operating life of the Li-ion ESS under the actual operating condition differs significantly from the nominal life provided by the manufacturer under the standard condition and the full discharge mode.This paper provides an accurate costing method for the ESS participating in grid frequency regulation to help the promotion of the ESS to participate in the ancillary service market.
文摘In this work,chaos game optimization(CGO),a robust optimization approach,is employed for efficient design of a novel cascade controller for four test systems with interconnected power systems(IPSs)to tackle load-frequency con-trol(LFC)difficulties.The CGO method is based on chaos theory principles,in which the structure of fractals is seen via the chaotic game principle and the fractals’self-similarity characteristics are considered.CGO is applied in LFC studies as a novel application,which reveals further research gaps to be filled.For practical implementation,it is also highly desirable to keep the controller structure simple.Accordingly,in this paper,a CGO-based controller of fractional-order(FO)proportional-integral-derivative-FO proportional-integral(FOPID-FOPI)controller is proposed,and the integral time multiplied absolute error performance function is used.Initially,the proposed CGO-based FOPID-FOPI controller is tested with and without the nonlinearity of the governor dead band for a two-area two-source model of a non-reheat unit.This is a common test system in the literature.A two-area multi-unit system with reheater-hydro-gas in both areas is implemented.To further generalize the advantages of the proposed scheme,a model of a three-area hydrothermal IPS including generation rate constraint nonlinearity is employed.For each test system,comparisons with relevant existing studies are performed.These demonstrate the superiority of the proposed scheme in reducing settling time,and frequency and tie-line power deviations.