Hybrid EMT-TS Simulation Strategies to Study High Bandwidth MMC-Based HVdc Systems

TL;DR

This paper introduces a hybrid simulation framework combining EMT and TS models for high-bandwidth MMC-based HVdc systems, improving simulation efficiency and enabling detailed system-level analysis.

Contribution

It presents a novel hybrid simulation approach for high-fidelity HVdc models, including buffer sizing methods and co-simulation of EMT and TS models.

Findings

Hybrid simulation framework enables efficient co-simulation of EMT and TS models.

Buffer sizing significantly affects simulation accuracy and performance.

The approach allows detailed analysis of high-bandwidth MMC-based HVdc systems.

Abstract

Modular multilevel converters (MMCs) are widely used in the design of modern high-voltage direct current (HVdc) transmission system. High-fidelity dynamic models of MMCs-based HVdc system require small simulation time step and can be accurately modeled in electro-magnetic transient (EMT) simulation programs. The EMT program exhibits slow simulation speed and limitation on the size of the model and brings certain challenges to test the high-fidelity HVdc model in system-level simulations. This paper presents the design and implementation of a hybrid simulation framework, which enables the co-simulation of the EMT model of Atlanta-Orlando HVdc line and the transient stability (TS) model of the entire Eastern Interconnection system. This paper also introduces the implementation of two high-fidelity HVdc line models simulated at different time steps and discusses a dedicated method for sizing the buffer areas on both sides of the HVdc line. The simulation results of the two HVdc models with different sizes of buffer areas are presented and compared.