The demands for massive renewable energy integration, passive network power supply, and global energy interconnection have all gradually increased, posing new challenges for high voltage direct current(HVDC) power tra...The demands for massive renewable energy integration, passive network power supply, and global energy interconnection have all gradually increased, posing new challenges for high voltage direct current(HVDC) power transmission systems, including more complex topology and increased diversity of bipolar HVDC transmission. This study proposes that these two factors have led to new requirements for HVDC control strategies. Moreover, due to the diverse applications of HVDC transmission technology, each station in the system has different requirements. Furthermore, the topology of the AC-DC converter is being continuously developed, revealing a trend towards hybrid converter stations.展开更多
In view of the imbalanced distribution of power load and resources, including the status of “electric shortage” in some cities in our country, the article discusses the long-distance transmission technology. It main...In view of the imbalanced distribution of power load and resources, including the status of “electric shortage” in some cities in our country, the article discusses the long-distance transmission technology. It mainly analyzed two ways of the long-distance transmission: UHV AC transmission and UHV DC transmission. The fractional frequency transmission technology and half wavelength AC transmission technology of AC transmission are introduced. Some key technologies of long-distance transmission are described. It has a guess for long-distance transmission future direction.展开更多
基于模块化多电平换流器MMC(modular multilevel converter)的高压直流输电HVDC(high voltage direct current transmission)因具有无源网络支撑等优势而被广泛应用于大容量新能源外送消纳。受电力电子设备交互作用等因素影响,送端系统...基于模块化多电平换流器MMC(modular multilevel converter)的高压直流输电HVDC(high voltage direct current transmission)因具有无源网络支撑等优势而被广泛应用于大容量新能源外送消纳。受电力电子设备交互作用等因素影响,送端系统易发生振荡失稳现象。首先,建立了直驱风电场经MMC-HVDC并网送端系统的小扰动线性化模型,分析了风场有功输出对系统稳定性的影响。然后,建立了MMC及风机并网变流器交流侧dq阻抗模型,从阻抗角度揭示了送端系统振荡失稳机理。进一步,提出了基于MMC交流电压控制外环q轴附加阻尼的振荡抑制策略,可满足系统满功率范围内的运行稳定性要求。最后,基于全比例模型的仿真结果验证了所提振荡抑制策略的有效性。展开更多
该文研究了电网换相换流器高压直流输电(line commutated converter high voltage direct current,LCC-HVDC)系统逆变侧采用不同锁相环时,锁相环控制回路比例–积分(proportional integral,PI)参数变化对直流控制回路稳定性的影响。首先...该文研究了电网换相换流器高压直流输电(line commutated converter high voltage direct current,LCC-HVDC)系统逆变侧采用不同锁相环时,锁相环控制回路比例–积分(proportional integral,PI)参数变化对直流控制回路稳定性的影响。首先,分别建立了逆变侧锁相环采用滑动平均滤波(mo ving average filter,MAF)和级联延时消去滤波(cascaded delayed signal cancellation,CDSC)的LCC-HVDC小干扰动态模型,并通过电磁暂态仿真验证了该模型的正确性。其次,基于拉普拉斯变换获得系统定电压控制回路的传递函数,利用奈奎斯特稳定判据以及稳定裕度指标分析不同锁相环对定电压控制回路稳定性的影响,并进行了机理分析,同时在PSCAD/EMTDC的电磁暂态模型上进行了验证。最后,进一步在LCC-HVDC工程模型上对该文所得结论的普适性进行了仿真验证。展开更多
高压直流输电系统嵌入大型交流系统,将进一步增加换相失败、直流闭锁等故障对系统安全稳定的影响,交流系统与直流系统的交互作用,将使系统动态更加复杂。针对电网不同运行方式下大扰动后系统复杂动态响应特性分析难题,文中提出一种基于...高压直流输电系统嵌入大型交流系统,将进一步增加换相失败、直流闭锁等故障对系统安全稳定的影响,交流系统与直流系统的交互作用,将使系统动态更加复杂。针对电网不同运行方式下大扰动后系统复杂动态响应特性分析难题,文中提出一种基于机电-电磁混合仿真与机器学习的智能分析方法。该方法基于主成分分析(principal components analysis,PCA)降维、基于密度的噪声应用空间聚类(density-based spatial clustering of applications with noise,DBSCAN)、K-means等算法建立二阶段聚类模型,可针对直流落点近区严重故障后大量混合仿真动态曲线在高维空间中自动聚类,并给出相应标识与严重程度;提取交直流系统在不同故障下的典型动态模式,自动标注并识别各模式下主导安全稳定问题。文中所提方法的有效性在2025年华东电网运行方式中得以验证,仿真结果表明,所提方法可有效提取不同故障下系统动态模式,将有效支撑后续复杂故障下的交直流系统动态机理分析。展开更多
With the rapid development of renewable energy,wind-thermal-bundled power transmission by line-commutated converter based high-voltage direct current(LCC-HVDC)systems has been widely developed.The dynamic interaction ...With the rapid development of renewable energy,wind-thermal-bundled power transmission by line-commutated converter based high-voltage direct current(LCC-HVDC)systems has been widely developed.The dynamic interaction mechanisms among permanent magnet synchronous generators(PMSGs),synchronous generators(SGs),and LCC-HVDC system become complex.To deal with this issue,a path analysis method(PAM)is proposed to study the dynamic interaction mechanism,and the damping reconstruction is used to analyze the damping characteristic of the system.First,based on the modular modeling,linearized models for the PMSG subsystem,the LCC-HVDC subsystem,and the SG subsystem are established.Second,based on the closed-loop transfer function diagram of the system,the disturbance transfer path and coupling relationship among subsystems are analyzed by the PAM,and the damping characteristic analysis of the SG-dominated oscillation mode is studied based on the damping reconstruction.Compared with the PAM,the small-signal model of the system is obtained and eigenvalue analysis results are presented.Then,the effect of the control parameters on the damping characteristic is analyzed and the conclusions are verified by time-domain simulations.Finally,the penalty functions of the oscillation modes and decay modes are taken as the objective function,and an optimization strategy based on the Monte Carlo method is proposed to solve the parameter optimization problem.Numerical simulation results are presented to validate the effectiveness of the proposed strategy.展开更多
基金supported by the State Grid Science & Technology Project (GEIGC-E-[2018]026)
文摘The demands for massive renewable energy integration, passive network power supply, and global energy interconnection have all gradually increased, posing new challenges for high voltage direct current(HVDC) power transmission systems, including more complex topology and increased diversity of bipolar HVDC transmission. This study proposes that these two factors have led to new requirements for HVDC control strategies. Moreover, due to the diverse applications of HVDC transmission technology, each station in the system has different requirements. Furthermore, the topology of the AC-DC converter is being continuously developed, revealing a trend towards hybrid converter stations.
文摘In view of the imbalanced distribution of power load and resources, including the status of “electric shortage” in some cities in our country, the article discusses the long-distance transmission technology. It mainly analyzed two ways of the long-distance transmission: UHV AC transmission and UHV DC transmission. The fractional frequency transmission technology and half wavelength AC transmission technology of AC transmission are introduced. Some key technologies of long-distance transmission are described. It has a guess for long-distance transmission future direction.
文摘基于模块化多电平换流器MMC(modular multilevel converter)的高压直流输电HVDC(high voltage direct current transmission)因具有无源网络支撑等优势而被广泛应用于大容量新能源外送消纳。受电力电子设备交互作用等因素影响,送端系统易发生振荡失稳现象。首先,建立了直驱风电场经MMC-HVDC并网送端系统的小扰动线性化模型,分析了风场有功输出对系统稳定性的影响。然后,建立了MMC及风机并网变流器交流侧dq阻抗模型,从阻抗角度揭示了送端系统振荡失稳机理。进一步,提出了基于MMC交流电压控制外环q轴附加阻尼的振荡抑制策略,可满足系统满功率范围内的运行稳定性要求。最后,基于全比例模型的仿真结果验证了所提振荡抑制策略的有效性。
文摘该文研究了电网换相换流器高压直流输电(line commutated converter high voltage direct current,LCC-HVDC)系统逆变侧采用不同锁相环时,锁相环控制回路比例–积分(proportional integral,PI)参数变化对直流控制回路稳定性的影响。首先,分别建立了逆变侧锁相环采用滑动平均滤波(mo ving average filter,MAF)和级联延时消去滤波(cascaded delayed signal cancellation,CDSC)的LCC-HVDC小干扰动态模型,并通过电磁暂态仿真验证了该模型的正确性。其次,基于拉普拉斯变换获得系统定电压控制回路的传递函数,利用奈奎斯特稳定判据以及稳定裕度指标分析不同锁相环对定电压控制回路稳定性的影响,并进行了机理分析,同时在PSCAD/EMTDC的电磁暂态模型上进行了验证。最后,进一步在LCC-HVDC工程模型上对该文所得结论的普适性进行了仿真验证。
文摘高压直流输电系统嵌入大型交流系统,将进一步增加换相失败、直流闭锁等故障对系统安全稳定的影响,交流系统与直流系统的交互作用,将使系统动态更加复杂。针对电网不同运行方式下大扰动后系统复杂动态响应特性分析难题,文中提出一种基于机电-电磁混合仿真与机器学习的智能分析方法。该方法基于主成分分析(principal components analysis,PCA)降维、基于密度的噪声应用空间聚类(density-based spatial clustering of applications with noise,DBSCAN)、K-means等算法建立二阶段聚类模型,可针对直流落点近区严重故障后大量混合仿真动态曲线在高维空间中自动聚类,并给出相应标识与严重程度;提取交直流系统在不同故障下的典型动态模式,自动标注并识别各模式下主导安全稳定问题。文中所提方法的有效性在2025年华东电网运行方式中得以验证,仿真结果表明,所提方法可有效提取不同故障下系统动态模式,将有效支撑后续复杂故障下的交直流系统动态机理分析。
基金supported in part by the National Natural Science Foundation of China(No.U22B20109).
文摘With the rapid development of renewable energy,wind-thermal-bundled power transmission by line-commutated converter based high-voltage direct current(LCC-HVDC)systems has been widely developed.The dynamic interaction mechanisms among permanent magnet synchronous generators(PMSGs),synchronous generators(SGs),and LCC-HVDC system become complex.To deal with this issue,a path analysis method(PAM)is proposed to study the dynamic interaction mechanism,and the damping reconstruction is used to analyze the damping characteristic of the system.First,based on the modular modeling,linearized models for the PMSG subsystem,the LCC-HVDC subsystem,and the SG subsystem are established.Second,based on the closed-loop transfer function diagram of the system,the disturbance transfer path and coupling relationship among subsystems are analyzed by the PAM,and the damping characteristic analysis of the SG-dominated oscillation mode is studied based on the damping reconstruction.Compared with the PAM,the small-signal model of the system is obtained and eigenvalue analysis results are presented.Then,the effect of the control parameters on the damping characteristic is analyzed and the conclusions are verified by time-domain simulations.Finally,the penalty functions of the oscillation modes and decay modes are taken as the objective function,and an optimization strategy based on the Monte Carlo method is proposed to solve the parameter optimization problem.Numerical simulation results are presented to validate the effectiveness of the proposed strategy.
