光伏、火电打捆经串补送出系统的次同步振荡研究

光伏、火电捆绑经过含串补的交流系统送出是一种合理可行的并网方案。本文基于加入了并网光伏的IEEE次同步振荡第一标准模型,利用复转矩系数法和时域仿真法分析了并网光伏对系统次同步振荡特性的影响。根据相位补偿原理,考虑发电机转速偏差信号的传输延迟,分别设计了基于多通道结构的有功和无功型附加阻尼控制器以及混合型附加阻尼控制器;论证了配置附加阻尼控制器并未对并网光伏的稳定出力产生影响。这种在光伏逆变器上配置附加阻尼控制器的思路可以作为抑制火电机组次同步振荡的备用方案。分析了并网光伏容量、附加阻尼控制器类型对次同步振荡抑制效果的影响,频域和时域仿真结果表明并网光伏容量越大,对次同步振荡的抑制效果越好;相比单一的附加阻尼控制器,混合型附加阻尼控制器对次同步振荡的抑制效果更好。

Research on Subsynchronous Oscillations in Power System With Photovoltaic-thermal-bundled Power Transimitted by Series Compensation

The power output of bundled photovoltaic (PV) and thermal generators which connect power grid through series compensation AC system is a reasonable and operable scheme. Based on the modified IEEE SSR first benchmark model which integrated with grid-connected PV, complex torque coefficient method and time-domain simulation method are used to analyze the effects of PV on subsynchronous oscillation characteristics of pwer system. According to the transmission delay of speed deviation signal of the generator and phase compensation principle, active and reactive type additional damping controller and mixed additional damping controller are designed based on multi-channel structure. It is demonstrated that the additional damping controller does not affect the stability operation of gird-connection PV. The idea of configuring additional damping controller in PV inverter can be used as a backup plan to suppress SSO of thermal power unit. The influence of gird-connection PV capacities and types of additional damping controller on suppressing SSO are also analyzed, frequency-domain and time-domain simulation results show that the larger grid-connected PV capacity, the better suppression effects on SSO. Compared to single additional damping control, the hybrid additional damping controller has a better suppression effects on SSO.