大型互联电网区间低频振荡时滞鲁棒控制方法与协调控制策略研究

Conventional control method for damping interarea oscillations, based on ordinary differential equations model of interconnected power systems, can not accurately reveal interarea oscillation control mechanism of interconnected power systems in the environment of wide area measurement system (WAMS), and the performance of its damping controller may dramatically deteriorate or even have no effect when it is subjected to time delay and uncertainty. In the project, interarea oscillation control mechanism of interconnected power systems by considering coupling influence of time delay and uncertainty is intensively investigated. Retarted functional differential equations are proposed to describe time-delay power system with uncertainty, and time delay robust control model for damping interarea oscillation of interconnected power systems is constructed. Delay-dependent robust stability analysis method of power systems based on free-weighting matrices (FWM) method and order reduction technique is given. In order to overcome the limitation of residue method only suitable for non-delay scenarios, a theory of location and input signal selection of damping controller based on modified residue method is also given. Multiobjective damping control optimization design method based on FWM and particle swarm optimization (PSO), and a LMI based stabilization design approach for time delay robust damping controller are presented, which extends damping controller design approach into the circumstance of time delay and uncertainty. A multiple-delay robust coordinated control strategy for damping controllers, based on FWM method with multiple delays and multiobjective PSO, is proposed to improve the ability of damping multiple interarea oscillations for interconnected power systems under time delays.

传统区间振荡控制方法以常微分方程描述互联电力系统，难以精确揭示广域测量环境下互联电网区间振荡控制机理，所设计的阻尼控制器在存在时滞和不确定性影响时性能大大降低甚至失效。本项目综合考虑时滞和不确定性耦合影响，对互联电网区间振荡控制机理进行深入研究，提出采用滞后型泛函微分方程描述具有不确定性的时滞电力系统，构建互联电网区间振荡时滞鲁棒控制模型，提出基于自由权矩阵方法和降阶技术的电力系统时滞鲁棒稳定判定方法；提出基于改进留数法的阻尼控制器选点选信号理论，克服留数法仅适用于无时滞情形的局限性；提出基于自由权矩阵方法和粒子群优化算法的阻尼控制器多目标优化设计方法和基于LMI的区间振荡时滞鲁棒阻尼控制器镇定设计方法，实现阻尼控制器设计方法向时滞和不确定性领域的拓展和延伸；提出基于多时滞自由权矩阵方法和多目标粒子群优化算法的阻尼控制器多时滞鲁棒协调控制策略，提高电力系统时滞条件下抑制多个区间振荡的能力。

我国电网已经成为世界上规模最大、电压等级最高、运行控制最为复杂的多区域互联电力系统。随着智能电网、泛在电力物联网和能源互联网的建设，我国电力系统运行环境和运行方式更加复杂，电力系统发生区间低频振荡的风险大大增加，区间振荡已成为互联电网安全稳定运行的巨大威胁。本项目基于上述国家和行业的重大需求，深入研究互联电网区间振荡机理和控制方法。传统区间振荡控制方法以常微分方程描述互联电力系统，难以精确揭示广域测量环境下互联电网区间振荡控制机理，所设计的阻尼控制器在存在时滞和不确定性影响时性能大大降低甚至失效。本项目综合考虑时滞和不确定性耦合影响，对互联电网区间振荡控制机理进行深入研究，提出采用滞后型泛函微分方程描述具有不确定性的时滞电力系统，构建了互联电网区间振荡时滞鲁棒控制模型，提出了基于自由权矩阵方法和降阶技术的电力系统时滞鲁棒稳定判定方法；提出基于自由权矩阵方法和粒子群优化算法的阻尼控制器多目标优化设计方法和基于LMI的区间振荡时滞鲁棒阻尼控制器镇定设计方法，实现了阻尼控制器设计方法向时滞和不确定性领域的拓展和延伸；针对UPFC阻尼控制器在镇定信号传输存在时滞时会导致电力系统阻尼性能降低甚至失稳的问题，建立了计及信号传输时滞的UPFC阻尼控制模型，提出了综合考虑阻尼比和时滞稳定裕度的UPFC阻尼控制策略设计方法，将该设计问题转化为约束优化问题，并提出求解该问题的双层优化结构算法, 该算法具有保守性低和易于实现等优点，通过该算法可以获得最优的UPFC阻尼控制策略，使得电力系统既能有效阻尼低频振荡，又能容忍一定的信号传输时滞；提出基于多时滞自由权矩阵方法和多目标粒子群优化算法的阻尼控制器多时滞鲁棒协调控制策略，提高电力系统时滞条件下抑制多个区间振荡的能力。本项目所取得的上述研究成果对有效抑制互联电网区间振荡、确保电力系统安全稳定运行具有重要的理论意义和实用价值。