Large transmission networks are often represented with short circuit network equivalents to share with neighboring utilities and distribution providers. The computation of network equivalents for short circuit studies is straightforward in systems predominantly based on conventional synchronous generators (SGs). However, the integration of renewable powered plants such as solar and wind parks (WPs) introduces inverter-based resources (IBRs) in the grid with different and nonlinear fault current characteristics. The increasing share of IBRs changes the way power systems respond during disturbances. The application of conventional approach to obtain network equivalents based on the computation of Thevenin equivalent at the point of interest to systems with high share of IBRs will result in misleading short circuit calculations. This paper is the first step in the identification of active nonlinear network equivalents for short circuit studies in systems with IBRs. A new concept of voltage dependent network equivalents (VDNEs) is proposed. Considering the increasing complexity of networks with several and different type of IBR installations, a measurement-based approach using simulated fault currents is proposed to obtain VDNEs. The short-circuit response of VDNEs are validated considering a network with WPs consisting of Type-IV/Full-Size Converter (FSC) wind turbine generators (WTGs).

大型输电网络通常用等效的短路网络表示，以便与邻近的公用事业和配电供应商共享。在主要基于传统同步发电机 (SG) 的系统中，用于短路研究的网络等效计算很简单。然而，太阳能和风电场 (WP) 等可再生发电厂的整合在电网中引入了具有不同非线性故障电流特性的基于逆变器的资源 (IBR)。IBR 份额的增加改变了电力系统在干扰期间的响应方式。应用传统方法来获得网络等效值，该方法基于对具有高 IBR 份额的系统感兴趣点的戴维宁等效值计算，将导致误导性短路计算。本文是识别具有 IBR 的系统中短路研究的有源非线性网络等效项的第一步。提出了电压相关网络等效物 (VDNE) 的新概念。考虑到具有多个不同类型 IBR 装置的网络日益复杂，提出了一种使用模拟故障电流的基于测量的方法来获得 VDNE。VDNE 的短路响应通过考虑由 IV 型/全尺寸转换器 (FSC) 风力涡轮发电机 (WTG) 组成的 WP 网络进行验证。考虑到具有多个不同类型 IBR 装置的网络日益复杂，提出了一种使用模拟故障电流的基于测量的方法来获得 VDNE。VDNE 的短路响应通过考虑由 IV 型/全尺寸转换器 (FSC) 风力涡轮发电机 (WTG) 组成的 WP 网络进行验证。考虑到具有多个不同类型 IBR 装置的网络日益复杂，提出了一种使用模拟故障电流的基于测量的方法来获得 VDNE。VDNE 的短路响应通过考虑由 IV 型/全尺寸转换器 (FSC) 风力涡轮发电机 (WTG) 组成的 WP 网络进行验证。