Lihua Li, Hong Zhou, F. Luo, Xiangyang Lin, Yang Han
{"title":"Control Strategy for Low Voltage Ride Through (LVRT) Operation of Two-Stage Photovoltaic Power Generation System","authors":"Lihua Li, Hong Zhou, F. Luo, Xiangyang Lin, Yang Han","doi":"10.1109/SPEC.2018.8636020","DOIUrl":null,"url":null,"abstract":"This paper presents an improved low voltage ride through (LVRT) control strategy for the two-stage photovoltaic (PV) power generation system by adding discharging circuit at the DC-link of the inverter and modifying the active and reactive current reference to the DC/AC inverter when grid voltage sag occurs. The 500kVA two-stage photovoltaic power system model is built in PSCAD/EMTDC platform, which consists of PV arrays, Boost converter and 3-phase DC/AC inverter. The maximum power point tracking (MPPT) control scheme is adopted in the Boost converter, and the dual-loop control structure is utilized for the DC/AC inverter, where the outer voltage loop is used for maintaining DC-link voltage, and the inner current loop is used for improving dynamic response for current tracking. Also, a separate DC voltage loop is adopted in the discharging circuit for the LVRT operation. Simulation in PSCAD/EMTDC platform verifies the validity of the proposed control strategies under symmetrical voltage sag conditions","PeriodicalId":335893,"journal":{"name":"2018 IEEE 4th Southern Power Electronics Conference (SPEC)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"4","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"2018 IEEE 4th Southern Power Electronics Conference (SPEC)","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/SPEC.2018.8636020","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 4
Abstract
This paper presents an improved low voltage ride through (LVRT) control strategy for the two-stage photovoltaic (PV) power generation system by adding discharging circuit at the DC-link of the inverter and modifying the active and reactive current reference to the DC/AC inverter when grid voltage sag occurs. The 500kVA two-stage photovoltaic power system model is built in PSCAD/EMTDC platform, which consists of PV arrays, Boost converter and 3-phase DC/AC inverter. The maximum power point tracking (MPPT) control scheme is adopted in the Boost converter, and the dual-loop control structure is utilized for the DC/AC inverter, where the outer voltage loop is used for maintaining DC-link voltage, and the inner current loop is used for improving dynamic response for current tracking. Also, a separate DC voltage loop is adopted in the discharging circuit for the LVRT operation. Simulation in PSCAD/EMTDC platform verifies the validity of the proposed control strategies under symmetrical voltage sag conditions