CAJ | 학술논문

直流电网的动态性能分析需要用到线性化的直流电网模型。电压源型换流器作为直流电网的一个重要组成部件，其动态特性对直流电网动态特性具有重要影响。为准确地描述电压源型换流器的动态特性，提出两电平电压源型换流器的非线性模型，并进一步线性化得到电压源型换流器的线性化状态空间模型。所提出的模型包括了定位于网侧电压源的xy坐标及定位于电网公共连接点的 dq 坐标共计两套旋转坐标，其中交流电气部分的状态空间模型在 xy 坐标下建模，控制部分建模于dq 坐标，所提出的模型考虑了锁相环的动态过程。最后通过时域仿真对比验证所提出的非线性模型与线性化状态空间模型的正确性，所提出的非线性模型及线性化模型能够得到与电压源型换流器详细开关模型基本一致的响应曲线。
직류전망적동태성능분석수요용도선성화적직류전망모형。전압원형환류기작위직류전망적일개중요조성부건，기동태특성대직류전망동태특성구유중요영향。위준학지묘술전압원형환류기적동태특성，제출량전평전압원형환류기적비선성모형，병진일보선성화득도전압원형환류기적선성화상태공간모형。소제출적모형포괄료정위우망측전압원적xy좌표급정위우전망공공련접점적 dq 좌표공계량투선전좌표，기중교류전기부분적상태공간모형재 xy 좌표하건모，공제부분건모우dq 좌표，소제출적모형고필료쇄상배적동태과정。최후통과시역방진대비험증소제출적비선성모형여선성화상태공간모형적정학성，소제출적비선성모형급선성화모형능구득도여전압원형환류기상세개관모형기본일치적향응곡선。
ABSTRACT:Linearized model of a DC grid is required for analysis of its dynamic behavior. Voltage source converter (VSC) is a critical component of the DC grid, and its dynamic characteristics will significantly affect those of the dc grid. To accurately represent the dynamic characteristics of the VSC, non-linear model and its further linearized state-space model for a 2-level VSC is proposed. The proposed models include two rotational coordinates, i.e. the xy coordinate located at the voltage source and the dq coordinate located at the point of common connection in the grid, the state-space model for the electrical system is made in the xy coordinate, and the model for the control system is made in the dq coordinate. Dynamic process of the phase locked loop is also considered in the models. Time domain simulations verify the correctness of the proposed nonlinear and linearized state-space models, and the proposed models are able to achieve almost the same dynamic responses as the detailed switching model of the 2-level VSC.