One of the most important problems in the study of transient stability of power systems is the determination of perturbation’s maximum time of permanence without losing the synchronism of the generators that feed the...One of the most important problems in the study of transient stability of power systems is the determination of perturbation’s maximum time of permanence without losing the synchronism of the generators that feed the network. The problem is generally solved by either the application of the equal-area criterion or through numerical integration methods. In the present work, the phase-plane is proposed as an alternative tool to solve the above-mentioned problem with greater efficiency.展开更多
跟网型变流器(Grid-following voltage source converter,GFL-VSC)依赖锁相环(phase-locked loops,PLL)与电网保持同步,其在电网故障穿越期间由于电网传输极限降低而面临锁相同步失稳的风险。针对此问题,提出一种基于动态电压反馈的同...跟网型变流器(Grid-following voltage source converter,GFL-VSC)依赖锁相环(phase-locked loops,PLL)与电网保持同步,其在电网故障穿越期间由于电网传输极限降低而面临锁相同步失稳的风险。针对此问题,提出一种基于动态电压反馈的同步稳定控制方法,能够显著改善其在电网故障条件下的锁相同步稳定性。首先,建立了基于PLL同步的GFLVSC等效摇摆方程,通过等面积准则阐明了故障穿越期间GFL-VSC在平衡点存在的条件下仍发生同步失稳的内在机理。其次,在此基础上构建了基于动态电压反馈的锁相同步稳定控制策略,通过q轴电压反馈来自适应地调整故障期间d轴电流指令值,能够减缓PLL的加速过程,改善变流器的锁相同步稳定性。最后,通过仿真与实验,验证了所提控制策略的有效性。展开更多
文摘One of the most important problems in the study of transient stability of power systems is the determination of perturbation’s maximum time of permanence without losing the synchronism of the generators that feed the network. The problem is generally solved by either the application of the equal-area criterion or through numerical integration methods. In the present work, the phase-plane is proposed as an alternative tool to solve the above-mentioned problem with greater efficiency.
文摘跟网型变流器(Grid-following voltage source converter,GFL-VSC)依赖锁相环(phase-locked loops,PLL)与电网保持同步,其在电网故障穿越期间由于电网传输极限降低而面临锁相同步失稳的风险。针对此问题,提出一种基于动态电压反馈的同步稳定控制方法,能够显著改善其在电网故障条件下的锁相同步稳定性。首先,建立了基于PLL同步的GFLVSC等效摇摆方程,通过等面积准则阐明了故障穿越期间GFL-VSC在平衡点存在的条件下仍发生同步失稳的内在机理。其次,在此基础上构建了基于动态电压反馈的锁相同步稳定控制策略,通过q轴电压反馈来自适应地调整故障期间d轴电流指令值,能够减缓PLL的加速过程,改善变流器的锁相同步稳定性。最后,通过仿真与实验,验证了所提控制策略的有效性。
