Pub Date : 2024-09-04DOI: 10.1109/TSTE.2024.3454298
Woon-Gyu Lee;Hak-Man Kim
The optimal operation of an islanded AC microgrid system is achieved by proper power sharing among generators. The conventional distributed cost optimization strategies use a communication system to converge incremental costs. However, these methods are dependent on the distributed communication network and do not consider frequency deviations for real-time load variability. Thus, this paper proposes a DRL-based dynamic droop control strategy. The proposed twin delayed DDPG-based DRL interacts with the environment to learn the optimal droop gain for reducing generation cost and frequency deviation. The trained agent uses local information to transmit dynamic droop gains to the primary controller as demand load changes. It can simplify the control structure by omitting the secondary layer for optimal operation and power quality. The proposed control strategy is designed with a centralized DRL training process and distributed execution, enabling real-time distributed optimal operation. The comparison results with conventional distributed strategy confirms better control performance of the proposed strategy. Finally, the feasibility of the proposed strategy was verified by experiment on AC microgrid testbed.
{"title":"Deep Reinforcement Learning-Based Dynamic Droop Control Strategy for Real-Time Optimal Operation and Frequency Regulation","authors":"Woon-Gyu Lee;Hak-Man Kim","doi":"10.1109/TSTE.2024.3454298","DOIUrl":"10.1109/TSTE.2024.3454298","url":null,"abstract":"The optimal operation of an islanded AC microgrid system is achieved by proper power sharing among generators. The conventional distributed cost optimization strategies use a communication system to converge incremental costs. However, these methods are dependent on the distributed communication network and do not consider frequency deviations for real-time load variability. Thus, this paper proposes a DRL-based dynamic droop control strategy. The proposed twin delayed DDPG-based DRL interacts with the environment to learn the optimal droop gain for reducing generation cost and frequency deviation. The trained agent uses local information to transmit dynamic droop gains to the primary controller as demand load changes. It can simplify the control structure by omitting the secondary layer for optimal operation and power quality. The proposed control strategy is designed with a centralized DRL training process and distributed execution, enabling real-time distributed optimal operation. The comparison results with conventional distributed strategy confirms better control performance of the proposed strategy. Finally, the feasibility of the proposed strategy was verified by experiment on AC microgrid testbed.","PeriodicalId":452,"journal":{"name":"IEEE Transactions on Sustainable Energy","volume":"16 1","pages":"284-294"},"PeriodicalIF":8.6,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-04DOI: 10.1109/TSTE.2024.3454606
Jiabing Hu;Wei Wang;Yingbiao Li;Jianbo Guo
Power electronics (PE) equipment contains multiple timescale energy storage components and control loops. As a result, the dynamic process presents multiple timescale characteristics in PE-dominated power systems. For simplicity, single timescale dynamics are often the focus of corresponding analysis, and the influence of different timescales (i.e., cross-timescale analysis) is rarely considered. However, there is an interaction effect between multiple timescale controls and energy storage components, which complicates system dynamics. In this study, the cross-timescale impact of current control on the dynamics of rotor speed control timescale are evaluated. First, based on a two-machine two-area system comprising a phase-locked loop (PLL)-synchronized doubly fed induction generator (DFIG)-based wind turbine (WT), the influence of the PLL on cross-timescale interactions is revealed via modal analysis. Then, a current control equivalent circuit is derived for analyzing its cross-timescale influence on rotor motion, and the LC