A Bridge-Arm-Module-Based Fixed-Admittance ADC Model for Converters in EMT Simulation

Electromagnetic transient (EMT) simulation models, especially converter models, face challenges in meeting the demand for precise and fast simulation of complex dynamics in modern distribution systems. Difficulty in achieving both high accuracy and efficiency simultaneously is a key issue in converter modeling, especially in real-time simulation. To address this issue, this paper proposes a parametric fixed-admittance associated discrete circuit (ADC) converter model based on bridge arm modules (BAMs), with the aim of improving simulation precision and efficiency. The paper first establishes a parametric ADC model of the BAM. An optimal parameter calculation approach is introduced to ensure high fidelity through analysis of steadystate and transient characteristics. Furthermore, to mitigate initial errors caused by state switching, a cross-re-initialization (CRI) method combined with improved state determination expressions for specific topologies is developed, effectively correcting these errors without compromising computational efficiency. Simulation and experimental results validate the effectiveness of the BAM-ADC model, highlighting its high precision, high efficiency, and broad applicability.