Emergency DC Power Support Strategy Based on Coordinated Droop Control in Multi-Infeed HVDC System

With the complex hybrid AC-DC power system in China coming into being, the HVDC faults, such as DC block faults, have an enormous effect on the frequency stability of the AC side. In multi-infeed HVDC (MIDC) system, to improve the frequency stability of the receiving-end system, this paper proposes an emergency DC power support (EDCPS) strategy, which is based on a designed droop characteristic between the active power of LCC-HVDC lines and the receiving-end system frequency. Then, a coordinated optimization method is proposed to determine the droop coefficients of the MIDC lines. To test the proposed EDCPS method, the electromagnetic transient (EMT) model of a MIDC system is built on the CloudPSS platform, and the test results verify the effectiveness of the proposed EDCPS strategy.Comment: 5 pages, 11 figure

An Interface Method for Co-simulation of EMT Model and Shifted Frequency EMT Model Based on Rotational Invariance Techniques

The shifted frequency-based electromagnetic transient (SFEMT) simulation has greatly improved the computational efficiency of traditional electromagnetic transient (EMT) simulation for the ac grid. This letter proposes a novel interface for the co-simulation of the SFEMT model and the traditional EMT model. The general form of SFEMT modeling and the principle of analytical signal construction are first derived. Then, an interface for the co-simulation of EMT and SFEMT simulation is proposed based on rotational invariance techniques. Theoretical analyses and test results demonstrate the effectiveness of the proposed method