In this paper, a Battery Energy Storage System (BESS) dynamic model is presented, which considers average models of both Voltage Source Converter (VSC) and bidirectional buck-boost converter (dc-to-dc), for charging and discharging modes of operation. The dynamic BESS model comprises a simplified representation of the battery cells, which allows to simulate the effects of battery degradation, dc-to-dc converter, VSC, and the dynamics associated with the filter and transformer connecting the BESS to the grid. A decoupled dq-current control is used for the VSC, allowing the operation of the BESS in several modes, i.e., constant active and reactive power, constant power factor, voltage regulation, frequency regulation, oscillation damping, and a combination of the latter two. The proposed model is implemented in DSATools and tested for different contingencies on a benchmark system, and compared with a industry-grade BESS model used in power system dynamic studies. The importance of modeling the current control and dynamics of the dc-to-dc are demonstrated, especially when the battery cells are degraded due to, for instance, aging.

中文翻译：

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电池能量存储的动态建模及其在传输系统中的应用

本文提出了一种电池储能系统（BESS）动态模型，该模型考虑了电压源转换器（VSC）和双向降压-升压转换器（dc-dc）的平均模型，用于充电和放电操作模式。动态BESS模型包括电池单元的简化表示，它可以模拟电池退化，DC-DC转换器，VSC以及与将BESS连接到电网的滤波器和变压器相关的动力学特性。VSC采用去耦的dq电流控制，允许BESS在几种模式下运行，即恒定的有功功率和无功功率，恒定的功率因数，电压调节，频率调节，振荡阻尼以及后两者的组合。提议的模型在DSATools中实现，并在基准系统上针对不同的意外情况进行了测试，并与电力系统动态研究中使用的行业级BESS模型进行了比较。证明了建模直流到直流的电流控制和动态特性的重要性，尤其是当电池单元由于例如老化而退化时。