LVRT control strategy for two stage PV grid-connected system under unbalanced faults
In order to improve the grid-connected stability of two stage PV inverter based on boost circuit, the operation characteristic of PV inverter under unbalanced fault is studied. Combining with boost circuit regulating the DC bus voltage, a current control strategy based on negative sequence voltage f...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | zho |
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National Computer System Engineering Research Institute of China
2019-02-01
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| Series: | Dianzi Jishu Yingyong |
| Subjects: | |
| Online Access: | http://www.chinaaet.com/article/3000098380 |
| _version_ | 1818541060008181760 |
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| author | Gan Deshu Pei Xingyu Ke Qingpai Wu Haixiong Lin Guihui Cheng Xu |
| author_facet | Gan Deshu Pei Xingyu Ke Qingpai Wu Haixiong Lin Guihui Cheng Xu |
| author_sort | Gan Deshu |
| collection | DOAJ |
| description | In order to improve the grid-connected stability of two stage PV inverter based on boost circuit, the operation characteristic of PV inverter under unbalanced fault is studied. Combining with boost circuit regulating the DC bus voltage, a current control strategy based on negative sequence voltage feed forward is proposed to achieve LVRT. The conventional boost circuit voltage control mode and output current control strategy are analyzed. A DC bus voltage control outer loop based on PV array maximum power point voltage feed forward is introduced to change the boost circuit voltage control mode. By this way, the purpose of making the DC bus voltage stable and preventing over current of the inverter can be achieved. Then, a current control strategy based on negative sequence voltage feed forward is designed to ensure the output current three-phase symmetry under unbalanced fault. To provide a certain reactive power support to the grid, the current reference value is provided directly according to the voltage sage. In order to achieve the aforementioned current control method, a positive and negative sequence separation function module based on SOGI is designed. Finally, a 100 kW PV inverter PSCAD simulation model is built to verify the proposed control strategy. The result shows that the method not only can suppress the DC bus voltage rise rapidly and effectively, but also can make the inverter provide more dynamic reactive power support for the grid even when the single-phase voltage falls to 0.2 p.u. |
| first_indexed | 2024-12-11T22:03:36Z |
| format | Article |
| id | doaj.art-9ec4c31589e14dde9f933af8095d24e3 |
| institution | Directory Open Access Journal |
| issn | 0258-7998 |
| language | zho |
| last_indexed | 2024-12-11T22:03:36Z |
| publishDate | 2019-02-01 |
| publisher | National Computer System Engineering Research Institute of China |
| record_format | Article |
| series | Dianzi Jishu Yingyong |
| spelling | doaj.art-9ec4c31589e14dde9f933af8095d24e32022-12-22T00:49:01ZzhoNational Computer System Engineering Research Institute of ChinaDianzi Jishu Yingyong0258-79982019-02-0145212412810.16157/j.issn.0258-7998.1814303000098380LVRT control strategy for two stage PV grid-connected system under unbalanced faultsGan Deshu0Pei Xingyu1Ke Qingpai2Wu Haixiong3Lin Guihui4Cheng Xu5Guangdong Power Grid Company，Zhuhai Power Supply Bureau，Zhuhai 519000，ChinaGuangdong Power Grid Company，Zhuhai Power Supply Bureau，Zhuhai 519000，ChinaHuaTian Power CO. LTD.，Suzhou 215000，ChinaGuangdong Power Grid Company，Zhuhai Power Supply Bureau，Zhuhai 519000，ChinaGuangdong Power Grid Company，Zhuhai Power Supply Bureau，Zhuhai 519000，ChinaGuangdong Power Grid Company，Zhuhai Power Supply Bureau，Zhuhai 519000，ChinaIn order to improve the grid-connected stability of two stage PV inverter based on boost circuit, the operation characteristic of PV inverter under unbalanced fault is studied. Combining with boost circuit regulating the DC bus voltage, a current control strategy based on negative sequence voltage feed forward is proposed to achieve LVRT. The conventional boost circuit voltage control mode and output current control strategy are analyzed. A DC bus voltage control outer loop based on PV array maximum power point voltage feed forward is introduced to change the boost circuit voltage control mode. By this way, the purpose of making the DC bus voltage stable and preventing over current of the inverter can be achieved. Then, a current control strategy based on negative sequence voltage feed forward is designed to ensure the output current three-phase symmetry under unbalanced fault. To provide a certain reactive power support to the grid, the current reference value is provided directly according to the voltage sage. In order to achieve the aforementioned current control method, a positive and negative sequence separation function module based on SOGI is designed. Finally, a 100 kW PV inverter PSCAD simulation model is built to verify the proposed control strategy. The result shows that the method not only can suppress the DC bus voltage rise rapidly and effectively, but also can make the inverter provide more dynamic reactive power support for the grid even when the single-phase voltage falls to 0.2 p.u.http://www.chinaaet.com/article/3000098380two stage PV inverterunbalanced faultLVRTPSCAD/EMTDC |
| spellingShingle | Gan Deshu Pei Xingyu Ke Qingpai Wu Haixiong Lin Guihui Cheng Xu LVRT control strategy for two stage PV grid-connected system under unbalanced faults Dianzi Jishu Yingyong two stage PV inverter unbalanced fault LVRT PSCAD/EMTDC |
| title | LVRT control strategy for two stage PV grid-connected system under unbalanced faults |
| title_full | LVRT control strategy for two stage PV grid-connected system under unbalanced faults |
| title_fullStr | LVRT control strategy for two stage PV grid-connected system under unbalanced faults |
| title_full_unstemmed | LVRT control strategy for two stage PV grid-connected system under unbalanced faults |
| title_short | LVRT control strategy for two stage PV grid-connected system under unbalanced faults |
| title_sort | lvrt control strategy for two stage pv grid connected system under unbalanced faults |
| topic | two stage PV inverter unbalanced fault LVRT PSCAD/EMTDC |
| url | http://www.chinaaet.com/article/3000098380 |
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