Abstract
This article proposes a reduced-order small-signal closed-loop transfer function model based on Jordan continued-fraction expansion to assess the dynamic characteristics of the droop-controlled inverter and provide the preprocessing method for the real-time simulation of power systems. Firstly, dynamic phasors, time delay and zero-order hold are embedded into the small-signal model at the same time, then the closed-loop transfer function of the droop-controlled inverter is built. Compared with the existing closed-loop transfer function approaches, the accuracy of the built transfer function model is dramatically enhanced. Meanwhile, the inner cascaded voltage/current controller parameters are also designed. In order to directly obtain and preserve the maximum overshoot and settling time, which are main features to evaluate the system input-output dynamic response characteristics, the reduced second order closed-loop transfer function is proposed through the continued-fraction expansion regarding arbitrary points on the real frequency axis. Therein, this second order closed-loop transfer function with dynamic response of the original inverter is reduced to the lowest order. Furthermore, combined with the impedance-based approach, the proposed stability assessment approach is utilized to analyze the stability of the microgrid with multiple converters. Finally, simulations and experimental results demonstrate the convenience and accuracy of the proposed approach.
| Original language | English |
|---|---|
| Article number | 9034114 |
| Pages (from-to) | 1585-1595 |
| Number of pages | 11 |
| Journal | IEEE Transactions on Energy Conversion |
| Volume | 35 |
| Issue number | 3 |
| DOIs | |
| State | Published - Sep 2020 |
Funding
Manuscript received October 28, 2019; revised January 5, 2020; accepted March 8, 2020. Date of publication March 12, 2020; date of current version August 20, 2020. This work was supported in part by National Key Research and Development Program of China under Grant 2017YFF0108800, in part by National Natural Science Foundation of China under Grants 61773109 and 6143304, and in part by Major Program of National Natural Foundation of China under Grant 61573094. Paper no. TEC-01061-2019. (Corresponding authors: Sun Qiuye.) Wang Rui is with the Northeastern University, Liaoning 110819, China, and also with the Nanyang Technological University 637141, Singapore (e-mail: [email protected]).
Keywords
- Jordan continued-fraction expa-nsion
- Reduced-order
- droop-controlled inverter
- dynamic response