Providing system level frequency support from wind across the full operating range

传统的同步发电通过机器的物理惯性特性为电网提供固有频率支持。随着网络中同步发电机数量的减少，以及转换器接口的可再生能源发电的增加，现在必须从其他来源提供这种频率支持。利用风力涡轮机在惯性时间尺度（大约5 ms- 2s）上提供频率支持已经在一段时间内和多项研究中被确立为一种可行的主张。然而，利用风力发电提供这种频率支持仍然存在一些问题：>大多数关于风力发电机惯性支持的研究都是基于满功率运行。然而，电网规范要求在所有运行点都保证惯性供应。如何将惯性供应扩展到较低风速下？>考虑到运行条件的变化，量化惯性供应的最佳方法是什么？>在最大工作范围内提供惯性的最佳策略是什么，例如，削减与临时超额定？>在具有高变频器渗透率的网络中，网格形成算法在提供惯性方面如何表现，以及如何最好地操作/调整以提供频率支持？>采用电网形成控制方案的风力发电机在多大程度上可用于在2秒至几分钟的时间尺度内降低电压降？在事件发生之前，损失的能源生产成本是多少？>风力发电机级的惯性支持与风电场级的惯性支持-哪种是最佳的控制策略，以最大限度地提高频率支持，并最大限度地减少对单个风力发电机的负面影响？本计画将回顾目前的控制策略、效能与限制，以了解风力发电机频率支援的文献。应使用一系列时域和频域建模技术来实施频率支持的控制策略，评估整个工作点范围内的性能，并提出在低风速下提供惯性支持的改进建议。还应分析对WT能量生产和寿命健康的影响以及WT频率支持的局限性。还可以考虑增加能量存储以提高性能。

Conventional synchronous generation provides inherent frequency support to power networks via thephysical inertial properties of the machines. As the number of these synchronous generators on the networkdecreases, and converter-interfaced renewable generation increases, this frequency support must now beprovided from other sources. The use of wind turbines to provide frequency support at the inertial timescale(roughly 5ms - 2s) has been established as a feasible proposition for some time and in multiple studies.However, several issues remain for the use of wind power to provide this frequency support:>Most studies of inertial support from WTs are based on operation at full power. However, grid codesrequire inertia provision to be guaranteed at all operating points. How can inertia provision beextended to be provided at lower wind speeds?>What is the best way of quantifying inertia provision given the variation across operating conditions?>What is the optimum strategy for inertia provision across the maximum operating range e.g.,curtailment versus temporary over-rating?>How do grid forming algorithms perform in terms of inertia provision in a network with high converterpenetration and how can it best be operated/tuned to provide frequency support?>To what extent can WTs using Grid Forming control schemes be used to contribute to droop supportover the 2s to a few minutes timescale? What is the cost in terms of lost energy production prior toan event?>Inertia support at WT level vs farm level - which is the best control strategy to maximise frequencysupport and minimise negative impacts on individual WTs?This project should review the current control strategies, performance and limitations in the literature forfrequency support from WTs. A range of time and frequency domain modelling techniques should be used toimplement control strategies for frequency support, assess performance across the operating point range andsuggest improvements for providing inertia support at low wind speeds. The impact on WT energy productionand lifetime health and the limitations of WTs for frequency support should also be analysed. The addition ofenergy storage to improve performance may also be considered.