An opportunistic maintenance model is presented for a continuously deteriorating series system with economical de-pendence. The system consists of two kinds of units, which are respectively subjected to the deteriorat...An opportunistic maintenance model is presented for a continuously deteriorating series system with economical de-pendence. The system consists of two kinds of units, which are respectively subjected to the deterioration failure described by Gamma process and the random failure described by Poisson process. A two-level opportunistic policy defined by three decision parameters is proposed to coordinate the different maintenance actions and minimize the long-run maintenance cost rate of the system. A computable expression of the average cost rate is established by using the renewal property of the stochastic process of the maintained system state. The optimal values of three deci- sion parameters are derived by an iteration approach based on the characteristic of Gamma process. The behavior of the proposed policy is illustrated through a numerical experiment. Comparative study with the widely used corrective maintenance policy demonstrates the advantage of the proposed opportunistic maintenance method in significantly reducing the maintenance cost. Simultane- ously, the applicable area of this opportunistic model is discussed by the sensitivity analysis of the set-up cost and random failure rate.展开更多
集中送出的新能源场站大多位于电网末端,随着其有功出力的增加,易出现静态电压失稳。该文将传统的阻抗模指标的应用对象由负荷推广至新能源场站,丰富了该指标在静态电压稳定评估方面的适用性场景,包括含无功补偿的新能源系统、新能源集...集中送出的新能源场站大多位于电网末端,随着其有功出力的增加,易出现静态电压失稳。该文将传统的阻抗模指标的应用对象由负荷推广至新能源场站,丰富了该指标在静态电压稳定评估方面的适用性场景,包括含无功补偿的新能源系统、新能源集群馈入系统、以及新能源多机多馈入系统。具体地,首先,分析新能源单馈入系统的临界静态电压稳定条件,并据此给出用于评估新能源场站静态电压稳定性的阻抗模裕度指标及稳定判据;其次,通过将无功补偿设备并入系统阻抗,分析无功补偿对于指标的影响;再次,证明在新能源的集群馈入系统中,公共耦合点(point of common coupling,PCC)的电压失稳将发生在单个新能源场站之前,并据此确定PCC点作为指标的计算节点;之后,为考虑多机多馈入系统中不同新能源场站间的影响,在指标的计算过程中,保留待评估的关键新能源场站,将其他新能源场站等值为阻抗,并入节点阻抗矩阵中,实现方法在多机多馈入系统中的扩展应用。最后,基于PSD-BPA中建立的单机单馈入系统、多机多馈入系统、以及某省实际大电网算例验证指标的有效性。展开更多
基金supported by the National Natural Science Foundation of China(6090400271201166)
文摘An opportunistic maintenance model is presented for a continuously deteriorating series system with economical de-pendence. The system consists of two kinds of units, which are respectively subjected to the deterioration failure described by Gamma process and the random failure described by Poisson process. A two-level opportunistic policy defined by three decision parameters is proposed to coordinate the different maintenance actions and minimize the long-run maintenance cost rate of the system. A computable expression of the average cost rate is established by using the renewal property of the stochastic process of the maintained system state. The optimal values of three deci- sion parameters are derived by an iteration approach based on the characteristic of Gamma process. The behavior of the proposed policy is illustrated through a numerical experiment. Comparative study with the widely used corrective maintenance policy demonstrates the advantage of the proposed opportunistic maintenance method in significantly reducing the maintenance cost. Simultane- ously, the applicable area of this opportunistic model is discussed by the sensitivity analysis of the set-up cost and random failure rate.
文摘集中送出的新能源场站大多位于电网末端,随着其有功出力的增加,易出现静态电压失稳。该文将传统的阻抗模指标的应用对象由负荷推广至新能源场站,丰富了该指标在静态电压稳定评估方面的适用性场景,包括含无功补偿的新能源系统、新能源集群馈入系统、以及新能源多机多馈入系统。具体地,首先,分析新能源单馈入系统的临界静态电压稳定条件,并据此给出用于评估新能源场站静态电压稳定性的阻抗模裕度指标及稳定判据;其次,通过将无功补偿设备并入系统阻抗,分析无功补偿对于指标的影响;再次,证明在新能源的集群馈入系统中,公共耦合点(point of common coupling,PCC)的电压失稳将发生在单个新能源场站之前,并据此确定PCC点作为指标的计算节点;之后,为考虑多机多馈入系统中不同新能源场站间的影响,在指标的计算过程中,保留待评估的关键新能源场站,将其他新能源场站等值为阻抗,并入节点阻抗矩阵中,实现方法在多机多馈入系统中的扩展应用。最后,基于PSD-BPA中建立的单机单馈入系统、多机多馈入系统、以及某省实际大电网算例验证指标的有效性。
