为了满足新型电力系统安全稳定运行的实际需求,研究构网型储能变流器(grid-forming energy storage converter)的控制策略和稳定机理具有重要意义。本研究建立了基于下垂控制的构网型储能并网系统小信号阻抗模型,采用复向量形式的阻抗...为了满足新型电力系统安全稳定运行的实际需求,研究构网型储能变流器(grid-forming energy storage converter)的控制策略和稳定机理具有重要意义。本研究建立了基于下垂控制的构网型储能并网系统小信号阻抗模型,采用复向量形式的阻抗模型表达式以简化建模,重点考虑了构网型储能功率同步环的动态特性,采用扫频法验证了阻抗模型的准确性。然后,基于广义Nyquist稳定性判据分析了构网型储能并网系统在不同控制参数和不同电网强度下的稳定性,理论分析结果与时域仿真分析具有一致性。研究结果表明,随着有功下垂系数或短路比的增大,构网型储能并网系统的稳定性均会变差。最后,在物理实验平台中进行了验证。展开更多
The convergence and stability analysis for two end-to-end rate-based congestion control algorithms with unavoidable random loss in packets are presented, which can be caused by, for example, errors on wireless links. ...The convergence and stability analysis for two end-to-end rate-based congestion control algorithms with unavoidable random loss in packets are presented, which can be caused by, for example, errors on wireless links. The convergence rates of these two algorithms are analyzed by linearizing them around their equilibrium points, since they are globally stable and can converge to their unique equilibrium points. Some sufficient conditions for local stability in the presence of round-trip delay are obtained based on the general Nyquist criterion of stability. The stability conditions can be considered to be more general. If random loss in the first congestion control algorithm is not considered, they reduce to the local stability conditions which have been obtained in some literatures. Furthermore, sufficient conditions for local stability of a new congestion control algorithm have also been obtained if random loss is not considered in the second congestion control algorithm.展开更多
文摘为了满足新型电力系统安全稳定运行的实际需求,研究构网型储能变流器(grid-forming energy storage converter)的控制策略和稳定机理具有重要意义。本研究建立了基于下垂控制的构网型储能并网系统小信号阻抗模型,采用复向量形式的阻抗模型表达式以简化建模,重点考虑了构网型储能功率同步环的动态特性,采用扫频法验证了阻抗模型的准确性。然后,基于广义Nyquist稳定性判据分析了构网型储能并网系统在不同控制参数和不同电网强度下的稳定性,理论分析结果与时域仿真分析具有一致性。研究结果表明,随着有功下垂系数或短路比的增大,构网型储能并网系统的稳定性均会变差。最后,在物理实验平台中进行了验证。
基金supported in part by the National Natural Science Foundation of China (10671170,60404022)the National Outstanding Youth Foundation of China (60525303)and the Natural Science Foundation of Hebei Province (07M005,F2008000864)
文摘The convergence and stability analysis for two end-to-end rate-based congestion control algorithms with unavoidable random loss in packets are presented, which can be caused by, for example, errors on wireless links. The convergence rates of these two algorithms are analyzed by linearizing them around their equilibrium points, since they are globally stable and can converge to their unique equilibrium points. Some sufficient conditions for local stability in the presence of round-trip delay are obtained based on the general Nyquist criterion of stability. The stability conditions can be considered to be more general. If random loss in the first congestion control algorithm is not considered, they reduce to the local stability conditions which have been obtained in some literatures. Furthermore, sufficient conditions for local stability of a new congestion control algorithm have also been obtained if random loss is not considered in the second congestion control algorithm.
