A State Variables Elimination-Based EMTP-Type Constant Admittance Equivalent Modeling Method for Power Electronic Converters

Abstract

Currently, a multitude of power electronic devices are connected to the grid, and the safe and stable operation of the grid depends on the analysis of electromagnetic transient (EMT) simulation technology. This paper proposes a state variables elimination-based EMTP-type constant admittance equivalent modeling method for power electronic converters. The method employs a three-layer architecture consisting of ‘network-nodal voltages-historical current source’. The low-order equivalent nodal voltage equation is generated by using matrix splitting and adding output equations. The proposed method is distinguished by a constant admittance matrix and the consideration of internal characteristics, which facilitates straightforward access to external circuit, low time-complexity, and uncomplicated modeling procedures in comparison with the classical node elimination method (NEM). Furthermore, it exhibits a degree of generality regarding modular and unitized electrical equipment. The accuracy of the proposed method is validated by comparison with the off-line EMT simulation and experiments. The test results demonstrate that the proposed method exhibits high accuracy and efficiency in a variety of scenarios.