Enhanced control of grid forming VSCs in a micro-grid system under unbalanced conditions

Zarei, S. F ; SHarif University of Technology | 2018

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  1. Type of Document: Article
  2. DOI: 10.1109/PEDSTC.2018.8343827
  3. Publisher: Institute of Electrical and Electronics Engineers Inc , 2018
  4. Abstract:
  5. Due to the technical advances in power electronic industry, employing inverter-based distributed energy resources (IBDERs) are increased in electric power systems. Distributed generators (DGs) with the rating capacity of few megawatts are commonly connected to the distribution level of power systems which are inherently unbalanced. A cluster of IBDERs and loads form a small-scale grid called microgrid (MG) which can operate independent of the main grid. In a MG, grid forming voltage source converters (VSCs) are used to control the voltages and frequency of the MG. However, grid forming VSCs with conventional control schemes cannot do this task properly when the MG is unbalanced. In this paper, a new control strategy is proposed to enable grid forming VSCs to work properly in unbalanced conditions. The proposed method does not need to increase the voltage control loop bandwidth, and therefore, is suitable for medium power VSCs applications operating at low switching frequencies. To examine the functionality of the proposed method, different scenarios are simulated on a test system in PSCAD/EMTDC environment. Also, a comparison with conventional control method is presented. © 2018 IEEE
  6. Keywords:
  7. Distribution system ; Terminal current controller ; Unbalanced condition ; Voltage controller ; Voltage source converter ; Electric power systems ; Energy resources ; Power electronics ; Voltage control ; Terminal currents ; Controllers
  8. Source: 9th Annual International Power Electronics, Drive Systems, and Technologies Conference, PEDSTC 2018, 13 February 2018 through 15 February 2018 ; Volume 2018-January , April , 2018 , Pages 380-385 ; 9781538646977 (ISBN)
  9. URL: https://ieeexplore.ieee.org/document/8343827