With the large-scale integration of renewable energy,the traditional maintenance arrangement during the load valley period cannot satisfy the transmission demand of renewable energy generation.Simultaneously,in a mark...With the large-scale integration of renewable energy,the traditional maintenance arrangement during the load valley period cannot satisfy the transmission demand of renewable energy generation.Simultaneously,in a market-oriented operation mode,the power dispatching control center aims to reduce the overall power purchase cost while ensuring the security of the power system.Therefore,a security-constrained transmission maintenance optimization model considering generation and operational risk costs is proposed herein.This model is built on double-layer optimization framework,where the upper-layer model is used for maintenance and generation planning,and the lowerlayer model is primarily used to address the operational security risk arising from the random prediction error and N-1 transmission failure.Correspondingly,a generation-maintenance iterative algorithm based on a defined cost feedback is included to increase solution efficiency.Generation cost is determined using long-term security-constrained unit commitment,and the operational risk cost is obtained using a double-layer N-1 risk assessment model.An electrical correlation coupling coefficient is proposed for the solution process to avoid maintenance of associated equipment simultaneously,thereby improving model convergence efficiency.The IEEE 118-bus system is used as a test case for illustration,and test results suggest that the proposed model and algorithm can reduce the total cost of transmission maintenance and system operation while effectively improving the solution efficiency of the joint optimization model.展开更多
A cost-effective ultra-dense wavelength-division-multiplexed passive optical network(UD-WDM PON) with speed of 12.5 Gbit/s and channel spacing of 12.5 GHz is proposed and demonstrated. The distributed feedback(DFB) la...A cost-effective ultra-dense wavelength-division-multiplexed passive optical network(UD-WDM PON) with speed of 12.5 Gbit/s and channel spacing of 12.5 GHz is proposed and demonstrated. The distributed feedback(DFB) lasers modulated in 4-level pulse amplitude modulation(4-PAM) format are used for downstream links, and the reflective semiconductor optical amplifiers(RSOAs) together with an optical frequency comb modulated in quadrature phase shift keying(QPSK) format are used for upstream links. We can achieve the error-free transmission of the upstream signals with speed of 12.5 Gbit/s even after 20 km single-mode fiber(SMF). The power penalty obtained by using the frequency comb generator instead of a tunable laser is around 0.5 d B. By using 11 DFB lasers and a set of intensity and phase modulators, it is possible to provide the seed light for 297 optical network units(ONUs) within the C-band.展开更多
This paper is devoted to investigating the dynamic output feedback(DOF)control problem of Markovian jump neutral-type stochastic systems with a guaranteed cost function.Both of the state and measurement equations cont...This paper is devoted to investigating the dynamic output feedback(DOF)control problem of Markovian jump neutral-type stochastic systems with a guaranteed cost function.Both of the state and measurement equations contain time delays.Mode-dependent DOF controllers are first designed such that the closed-loop system is asymptotically stable in mean-square and an adequate performance level of this system is guaranteed.Then,sufficient conditions for the solvability of this problem are derived in the form of linear matrix inequalities(LMIs).A numerical example is presented to reveal the effectiveness of our findings.展开更多
针对H桥级联型静止无功发生器(static var generator,SVG),提出了一种模型预测控制策略。实际交流侧输出电压值与理想的输出电压间存在电压残差,电压残差的存在会使电流跟踪存在误差。为此,利用电压残差与前一时刻的电流值进行反馈校正...针对H桥级联型静止无功发生器(static var generator,SVG),提出了一种模型预测控制策略。实际交流侧输出电压值与理想的输出电压间存在电压残差,电压残差的存在会使电流跟踪存在误差。为此,利用电压残差与前一时刻的电流值进行反馈校正,构成了闭环优化。利用级联型SVG存在大量开关冗余状态的特点,实现了直流侧电容电压均衡控制,同时降低了开关器件损耗。搭建了仿真平台和试验样机,仿真和实验结果验证了所提策略的有效性。展开更多
基金supported by the Scientific and Technological Project of State Grid Corporation of China“Multilevel maintenance scheduling and its coordination with medium-term and long-term dispatching decision”(No.5442DZ210012)。
文摘With the large-scale integration of renewable energy,the traditional maintenance arrangement during the load valley period cannot satisfy the transmission demand of renewable energy generation.Simultaneously,in a market-oriented operation mode,the power dispatching control center aims to reduce the overall power purchase cost while ensuring the security of the power system.Therefore,a security-constrained transmission maintenance optimization model considering generation and operational risk costs is proposed herein.This model is built on double-layer optimization framework,where the upper-layer model is used for maintenance and generation planning,and the lowerlayer model is primarily used to address the operational security risk arising from the random prediction error and N-1 transmission failure.Correspondingly,a generation-maintenance iterative algorithm based on a defined cost feedback is included to increase solution efficiency.Generation cost is determined using long-term security-constrained unit commitment,and the operational risk cost is obtained using a double-layer N-1 risk assessment model.An electrical correlation coupling coefficient is proposed for the solution process to avoid maintenance of associated equipment simultaneously,thereby improving model convergence efficiency.The IEEE 118-bus system is used as a test case for illustration,and test results suggest that the proposed model and algorithm can reduce the total cost of transmission maintenance and system operation while effectively improving the solution efficiency of the joint optimization model.
基金supported by the National Natural Science Foundation of China(No.61475015)
文摘A cost-effective ultra-dense wavelength-division-multiplexed passive optical network(UD-WDM PON) with speed of 12.5 Gbit/s and channel spacing of 12.5 GHz is proposed and demonstrated. The distributed feedback(DFB) lasers modulated in 4-level pulse amplitude modulation(4-PAM) format are used for downstream links, and the reflective semiconductor optical amplifiers(RSOAs) together with an optical frequency comb modulated in quadrature phase shift keying(QPSK) format are used for upstream links. We can achieve the error-free transmission of the upstream signals with speed of 12.5 Gbit/s even after 20 km single-mode fiber(SMF). The power penalty obtained by using the frequency comb generator instead of a tunable laser is around 0.5 d B. By using 11 DFB lasers and a set of intensity and phase modulators, it is possible to provide the seed light for 297 optical network units(ONUs) within the C-band.
基金supported by the National Natural Science Foundation of China under Grant Nos.61703226and 71961002Startup Project of Doctor Scientific Research of Guangxi University of Finance and Economics BS 2019002。
文摘This paper is devoted to investigating the dynamic output feedback(DOF)control problem of Markovian jump neutral-type stochastic systems with a guaranteed cost function.Both of the state and measurement equations contain time delays.Mode-dependent DOF controllers are first designed such that the closed-loop system is asymptotically stable in mean-square and an adequate performance level of this system is guaranteed.Then,sufficient conditions for the solvability of this problem are derived in the form of linear matrix inequalities(LMIs).A numerical example is presented to reveal the effectiveness of our findings.
文摘针对H桥级联型静止无功发生器(static var generator,SVG),提出了一种模型预测控制策略。实际交流侧输出电压值与理想的输出电压间存在电压残差,电压残差的存在会使电流跟踪存在误差。为此,利用电压残差与前一时刻的电流值进行反馈校正,构成了闭环优化。利用级联型SVG存在大量开关冗余状态的特点,实现了直流侧电容电压均衡控制,同时降低了开关器件损耗。搭建了仿真平台和试验样机,仿真和实验结果验证了所提策略的有效性。
