## Abstract:

Dq decoupling control is a widely used state-of-the-art control method of the inner current loop in VSC-based power electronics such as STATCOM, back-to-back converter, VSC-HVDC, DFIG system, etc. A key question in designing such a control system is how to select the parameters, or gains, of the PI controller in the loop, which determines the stability and time-domain performances of the system. This paper tries to sufficiently solve this problem. It starts with a theoretical insight of the popular zero-pole cancelling method, revealing a hidden problem of it. And then two new methods are proposed based on a solid control theory to overcome this problem. The studies of all methods are demonstrated on a real-grid based RTDS model. The results show that the proposed methods are sufficient to produce the PI parameters with given time-domain objectives.

*Z. Yan, Y. Xue and X. Zhang, "PI parameters determination in dq decoupling control of VSC terminals," 13th IET International Conference on AC and DC Power Transmission (ACDC 2017), Manchester, 2017, pp. 1-5, doi: 10.1049/cp.2017.0067.*

KEYWORDS: voltage source converter (VSC), dq decoupling control, PI parameters, PI tuning.