A nine-switch inverter with reduced leakage current for PV grid-tied systems using model-free predictive current control
To address the leakage current problem of transformerless three-phase inverters for photovoltaic (PV) grid-tied systems, H8 and improved H8 inverters were proposed to alleviate the leakage current of the PV grid-tied systems to a certain extent. However, these inverters cannot avoid the high-frequen...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2023-10-01
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| Series: | Energy Reports |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2352484723009228 |
| _version_ | 1827582135154769920 |
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| author | Lin Jiang Yu Chen Fukang Dai Kun Liu Xiangjun Chen Xiaosong He |
| author_facet | Lin Jiang Yu Chen Fukang Dai Kun Liu Xiangjun Chen Xiaosong He |
| author_sort | Lin Jiang |
| collection | DOAJ |
| description | To address the leakage current problem of transformerless three-phase inverters for photovoltaic (PV) grid-tied systems, H8 and improved H8 inverters were proposed to alleviate the leakage current of the PV grid-tied systems to a certain extent. However, these inverters cannot avoid the high-frequency switching of the generated common mode voltages (CMVs) among multiple levels, resulting in the unsatisfactory effect of the leakage current suppression of these inverter topologies. In order to solve these problems, an auxiliary power supply based nine-switch (AP-H9) inverter with reduced leakage current is proposed in this paper. A DC auxiliary circuit containing a switch is added to the inverter based on the H8 inverter, and one or more diodes are connected in reverse parallel with other corresponding switches to form the H9 inverter topology. By properly controlling the nine switches and using the reverse diodes to divide the DC voltage , the CMV of the system is limited to 2/3 times of the DC voltage, which can effectively suppress the leakage current of the PV grid-tied system. In addition, a model-free predictive current control (MFPCC) method based on ultra-local model is presented to eliminate the dependence of inverter control performance on system parameters. This method uses the voltage and current information of the previous two moments to realize the online update of the gain and dynamic part of the ultra-local model, and then obtain the predicted voltage vector for the next moment. Moreover, the switching loss optimization constraint is considered in the cost function to further improve the efficiency of the inverter. Finally, an experimental prototype is developed. The simulation and experimental results show that the proposed inverter and its control method can effectively suppress the leakage current of PV grid-tied system, and are insensitive to parameter changes. |
| first_indexed | 2024-03-08T22:46:11Z |
| format | Article |
| id | doaj.art-563f24d381fa495c9cbaaf00d5b47618 |
| institution | Directory Open Access Journal |
| issn | 2352-4847 |
| language | English |
| last_indexed | 2024-03-08T22:46:11Z |
| publishDate | 2023-10-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Energy Reports |
| spelling | doaj.art-563f24d381fa495c9cbaaf00d5b476182023-12-17T06:39:16ZengElsevierEnergy Reports2352-48472023-10-019396405A nine-switch inverter with reduced leakage current for PV grid-tied systems using model-free predictive current controlLin Jiang0Yu Chen1Fukang Dai2Kun Liu3Xiangjun Chen4Xiaosong He5Corresponding author.; School of Electrical Engineering and Information, Southwest Petroleum University, Cheng Du 610500, ChinaSchool of Electrical Engineering and Information, Southwest Petroleum University, Cheng Du 610500, ChinaSchool of Electrical Engineering and Information, Southwest Petroleum University, Cheng Du 610500, ChinaSchool of Electrical Engineering and Information, Southwest Petroleum University, Cheng Du 610500, ChinaSchool of Electrical Engineering and Information, Southwest Petroleum University, Cheng Du 610500, ChinaSchool of Electrical Engineering and Information, Southwest Petroleum University, Cheng Du 610500, ChinaTo address the leakage current problem of transformerless three-phase inverters for photovoltaic (PV) grid-tied systems, H8 and improved H8 inverters were proposed to alleviate the leakage current of the PV grid-tied systems to a certain extent. However, these inverters cannot avoid the high-frequency switching of the generated common mode voltages (CMVs) among multiple levels, resulting in the unsatisfactory effect of the leakage current suppression of these inverter topologies. In order to solve these problems, an auxiliary power supply based nine-switch (AP-H9) inverter with reduced leakage current is proposed in this paper. A DC auxiliary circuit containing a switch is added to the inverter based on the H8 inverter, and one or more diodes are connected in reverse parallel with other corresponding switches to form the H9 inverter topology. By properly controlling the nine switches and using the reverse diodes to divide the DC voltage , the CMV of the system is limited to 2/3 times of the DC voltage, which can effectively suppress the leakage current of the PV grid-tied system. In addition, a model-free predictive current control (MFPCC) method based on ultra-local model is presented to eliminate the dependence of inverter control performance on system parameters. This method uses the voltage and current information of the previous two moments to realize the online update of the gain and dynamic part of the ultra-local model, and then obtain the predicted voltage vector for the next moment. Moreover, the switching loss optimization constraint is considered in the cost function to further improve the efficiency of the inverter. Finally, an experimental prototype is developed. The simulation and experimental results show that the proposed inverter and its control method can effectively suppress the leakage current of PV grid-tied system, and are insensitive to parameter changes.http://www.sciencedirect.com/science/article/pii/S2352484723009228Transformerless three-phase inverterPV grid-tied systemLeakage currentCommon mode voltageUltra-local modelModel-free predictive current control |
| spellingShingle | Lin Jiang Yu Chen Fukang Dai Kun Liu Xiangjun Chen Xiaosong He A nine-switch inverter with reduced leakage current for PV grid-tied systems using model-free predictive current control Energy Reports Transformerless three-phase inverter PV grid-tied system Leakage current Common mode voltage Ultra-local model Model-free predictive current control |
| title | A nine-switch inverter with reduced leakage current for PV grid-tied systems using model-free predictive current control |
| title_full | A nine-switch inverter with reduced leakage current for PV grid-tied systems using model-free predictive current control |
| title_fullStr | A nine-switch inverter with reduced leakage current for PV grid-tied systems using model-free predictive current control |
| title_full_unstemmed | A nine-switch inverter with reduced leakage current for PV grid-tied systems using model-free predictive current control |
| title_short | A nine-switch inverter with reduced leakage current for PV grid-tied systems using model-free predictive current control |
| title_sort | nine switch inverter with reduced leakage current for pv grid tied systems using model free predictive current control |
| topic | Transformerless three-phase inverter PV grid-tied system Leakage current Common mode voltage Ultra-local model Model-free predictive current control |
| url | http://www.sciencedirect.com/science/article/pii/S2352484723009228 |
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