Small-signal modeling of LCC-HVDC systems with switching for electromagnetic timescale stability analyses of power systems
JIANG Kezheng1, ZHU Jianhang1, HU Jiabing1, WANG Haijiao2
1. State Key Laboratory of Advanced Electromagnetic Engineering Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China; 2. State Key Laboratory of Operation and Control of Renewable Energy & Storage Systems, China Electric Power Research Institute, Beijing 100192, China
Abstract：The wide application of power electronic equipment in power systems has caused significant changes in the dynamic behavior of modern power systems. As an important power system component, line commutated converter based high voltage direct current (LCC-HVDC) systems have an important impact on the safe, stable operation of power systems. Since the switching process in LCC-HVDC systems has intermittent time-varying characteristics and the switching frequency is equivalent to the electromagnetic timescale constant, these intermittent time-varying switching characteristics are the key to the stability of LCC-HVDC systems. This paper presents an electromagnetic timescale, small-signal model for LCC-HVDC systems that includes the switching process with a stability analysis. The model includes the nonlinear characteristics and the inherent periodic time-varying characteristics of LCC-HVDC systems for modeling the key challenges in the control system. Then, linear time-periodic theory is used to develop an electromagnetic timescale, small-signal model of the LCC-HVDC system. Finally, this model is compared with an existing model that does not consider the time-varying characteristics of the switching process to show the influence of the switching on the system stability with the results verified by time-domain simulations.
江克证, 朱建行, 胡家兵, 汪海蛟. 计及开关过程的LCC-HVDC小信号建模及其对电力系统电磁尺度稳定性分析[J]. 清华大学学报（自然科学版）, 2021, 61(5): 395-402.
JIANG Kezheng, ZHU Jianhang, HU Jiabing, WANG Haijiao. Small-signal modeling of LCC-HVDC systems with switching for electromagnetic timescale stability analyses of power systems. Journal of Tsinghua University(Science and Technology), 2021, 61(5): 395-402.
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2021, Vol. 61 
