• CSCD核心库收录期刊
  • 中文核心期刊
  • 中国科技核心期刊

Electric Power Construction ›› 2018, Vol. 39 ›› Issue (7): 48-56.doi: 10.3969/j.issn.1000-7229.2018.07.006

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Control Strategy of Low Voltage Ride Through for Grid-connected PV System Based on Modular Multilevel Converter

WU Chengjie, FU Chao, FAN Shixiong   

  1. 1.State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources (North China Electric Power University), Baoding 071003, Hebei Province, China;2. China Electric Power Research Institute, Beijing 100192, China
  • Online:2018-07-01
  • Supported by:
    This work is supported by National Key Research and Development Program of China(No.2016YFB0900203).

Abstract: With the increase of the penetration rate of photovoltaic power in the power system, the latest grid-connection rules require that the inverter of photovoltaic system should have the capability of low voltage ride through (LVRT). This paper aims at a grid-connected photovoltaic system based on modular multilevel converter (MMC). Firstly, the mathematical model of the system is established in the stationary coordinate system. In order to ensure that the photovoltaic plant can operate without network disconnection during grid fault, this paper adopts a current control strategy that can achieve constant sine current and constant active power, and proposes a calculation method for reactive power reference value and current limiting strategy. Using a proportional resonant (PR) controller, a control loop is designed to realize the LVRT of a grid-connected photovoltaic system. Finally, a simulation model is built in Matlab/Simulink to verify the validity and correctness of the control strategy used.

Key words: grid-connected photovoltaic inverter, low voltage ride through(LVRT), modular multilevel converter (MMC), current control strategy, reactive power reference

CLC Number: