1.Department of Electrical Engineering, Tsinghua University, Beijing 100084, China;2.State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China
The high-voltage large-capacity DC transformer (DCT) is important equipment of the DC grid and plays a key role in renewable energy collection and DC system interconnection. In order to realize fast electromagnetic transient simulation analysis of the DCT on the premise of reducing modelling complexity and keeping all electrical characteristics of the detailed model, a modular discrete decoupling equivalent modeling method is proposed in this paper. In this method, the controlled source is introduced to transfer the secondary information so as to realize the discrete decoupling between the external port and the internal port in the sub modules of the DCT. Thus, the high-dimensional admittance matrix of the system is divided into the low dimensional matrices which can be solved simultaneously to speed up the simulation. The proposed equivalent model not only has a simple modeling process, but also retains all the electrical characteristics of the detailed model. At the same time, it can accurately simulate the transient and steady-state characteristics of the DCT system, as well as some special operating conditions, including pre-charging, DC short-circuit faults and power reversals. It also significantly reduces the simulation time and improves the simulation efficiency. Finally, the correctness and effectiveness of the proposed modelling method are verified by PSCAD/EMTDC simulation analysis.
This work is supported by State Grid Corporation of China (No. XT71-18-030).
|||AN Feng, CUI Bin, BAI Ruihang, et al. Modular Discrete Decoupling Equivalent Modeling Method for High-voltage Large-capacity DC Transformer[J/OL]. Automation of Electric Power Systems, http://doi. org/10.7500/AEPS20200708004.|