论文标题
虚拟振荡器控制转换器中当前约束和不受约束的故障乘车的瞬时稳定性评估
Transient Stability Assessment for Current Constrained and Unconstrained Fault Ride-Through in Virtual Oscillator Controlled Converters
论文作者
论文摘要
统一的虚拟振荡器控制器（UVOC）继承了基于振荡器的网格形成（GFM）控制器提供的严格分析基础，并实现了快速过度流动的限制和故障乘车通行（FRT）。有效FRT的控制设计需要瞬态稳定性分析。现有的瞬态稳定性分析方法和研究受到限制，仅考虑当前不受约束的情况或忽略同时的功率角度和电压动力学。在电流受限的断层下，电压和功率角动力学被强烈耦合，并且在确定瞬态稳定性方面起着关键作用。因此，通常用于瞬态稳定性研究的两个分析，并不能对系统动态提供全面的见解。在这项工作中，提出了整个UVOC的FRT方法，并在电流饱和和不饱和对称的AC故障下开发了瞬态稳定性的全面建模和分析方法。我们在单个图形表示中利用整个系统的相平面分析，以获取对耦合电压和功率角动力学的整体见解。 FRT控制器和分析方法已通过模拟和硬件实验验证。结果表明，与下垂和虚拟同步机（VSM）类型二阶控制器不同，UVOC不会受到关键清除角的约束。
Unified virtual oscillator controller (uVOC) inherits the rigorous analytical foundation offered by oscillator based grid-forming (GFM) controllers and enables fast over-current limiting and fault ride-through (FRT). Control design for effective FRT requires transient stability analysis. Existing transient stability analysis methods and studies are limited in either considering only current unconstrained scenarios or neglecting the simultaneous power angle and voltage dynamics. Under current-constrained faults, the voltage and power angle dynamics are strongly coupled and both play critical roles in determining transient stability. Therefore, decoupled analysis of the two, typically used in transient stability studies, does not offer comprehensive insight into the system dynamics. In this work, the overall FRT method for uVOC is presented and a comprehensive modeling and analysis method for transient stability is developed under both current-saturated and unsaturated symmetrical AC faults. We utilize phase-plane analysis of the overall system in a single graphical representation to obtain holistic insights into the coupled voltage and power angle dynamics. The FRT controller and the analysis method have been validated through simulations and hardware experiments. The results demonstrate that uVOC is not constrained by a critical clearing angle unlike droop and virtual synchronous machine (VSM) type second order controllers.
