Line-Interactive UPS for Low-Voltage Microgrids

- Journal title : Journal of Power Electronics
- Volume 15, Issue 6, 2015, pp.1628-1639
- Publisher : The Korean Institute of Power Electronics
- DOI : 10.6113/JPE.2015.15.6.1628

Title & Authors

Line-Interactive UPS for Low-Voltage Microgrids

Zhang, Ping; Cai, Huanyu; Zhao, Hengyang; Shi, Jianjiang; He, Xiangning;

Zhang, Ping; Cai, Huanyu; Zhao, Hengyang; Shi, Jianjiang; He, Xiangning;

Abstract

Line-interactive uninterruptible power supply (UPS) systems are good candidates for providing energy storage within a microgrid. In this paper, a control scheme for a line-interactive UPS system applied in a low-voltage microgrid is presented. It is based on the Q-w and P-E droop control to achieve a seamless transition between grid-connected and stand-alone operation modes. Moreover, a new model for designing the controllers is built in the dq-frame based on the instantaneous power definition. The new-built model takes into account the dynamic performance of the output impedance of the inverter in the dq-frame and can be evaluated in the time domain. Compared to the traditional model based on the instantaneous power definition, the new-built model is more accurate to describe the dynamic performance of the system. Simulation and experimental results obtained with a microgrid consisting of two 40-kW line-interactive UPS systems are given to validate the control strategy of the line-active UPS system and the accuracy of the new-built model.

Keywords

Instantaneous power;Line-interactive UPS;Low-voltage microgrid;Power control;Q-w droop control;Seamless transition;

Language

English

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