PHOTOVOLTAIC SYSTEM, POWER SUPPLY SYSTEM, AND INSULATION FAULT DETECTION METHOD

    公开(公告)号:US20230402972A1

    公开(公告)日:2023-12-14

    申请号:US18450528

    申请日:2023-08-16

    CPC classification number: H02S50/00 G01R31/14 H02J1/10 H02J2300/24

    Abstract: A photovoltaic system, a power supply system, and an insulation fault detection method. An insulation impedance detection circuit is connected between a bus and the ground. The bus includes the direct current positive bus, the neutral bus, or the direct current negative bus. The insulation impedance detection circuit includes at least a switch. The direct current negative bus is connected to the neutral bus by using an electrical element or a voltage source. A controller obtains insulation impedance based on voltages to ground of the bus that are separately corresponding to the switch before and after the switch is turned on, and determines, based on the insulation impedance, whether there is an insulation fault in the photovoltaic system, to perform protection in a timely manner.

    IMPEDANCE DETECTION METHOD AND PHOTOVOLTAIC SYSTEM

    公开(公告)号:US20230378908A1

    公开(公告)日:2023-11-23

    申请号:US18364669

    申请日:2023-08-03

    CPC classification number: H02S50/10 H02J3/46 H02S40/34 G01R27/18 H02J2300/26

    Abstract: An impedance detection method and a photovoltaic system are provided to help reduce complexity and costs of impedance detection. The method includes: sampling a voltage between a direct current bus and a protective earthing at each of a first time point and a second time point, to obtain a first voltage value and a second voltage value; sampling a leakage current on the direct current bus at each of the first time point and the second time point, to obtain a first current value and a second current value; and calculating an insulation impedance value of a combiner box based on a difference between the first voltage value and the second voltage value and a difference between the first current value and the second current value, to determine whether impedance of the combiner box is abnormal.

    PHOTOVOLTAIC SYSTEM AND POWER SUPPLY SYSTEM
    4.
    发明公开

    公开(公告)号:US20230308050A1

    公开(公告)日:2023-09-28

    申请号:US18328902

    申请日:2023-06-05

    CPC classification number: H02S40/36 H02S40/32 H02M7/44

    Abstract: The photovoltaic system includes a first inverter circuit, a second inverter circuit, and a switch circuit. When the switch circuit is in the first state, a first photovoltaic array is connected to the direct current positive bus and the neutral bus through the switch circuit, and a second photovoltaic array is connected to the neutral bus and the direct current negative bus through the switch circuit. When the switch circuit is in the second state, the first photovoltaic array is connected to the neutral bus and the direct current negative bus through the switch circuit, and the second photovoltaic array is connected to the direct current positive bus and the neutral bus through the switch circuit. A potential of the photovoltaic array is changed to prevent a PID effect from occurring when the photovoltaic array is at a negative potential for a long time.

    PHOTOVOLTAIC POWER GENERATION SYSTEM AND METHOD

    公开(公告)号:US20220216690A1

    公开(公告)日:2022-07-07

    申请号:US17701940

    申请日:2022-03-23

    Abstract: A photovoltaic power generation system includes an inverter, a controller, and at least two direct current branch circuits. The leakage current detection apparatus is configured to: detect a leakage current of the direct current branch circuit on which the leakage current detection apparatus is located and send the leakage current to the controller. The controller is further configured to: when the photovoltaic power generation system runs and a value of a leakage current of the direct current branch circuit exceeds a preset range, determine that an insulation fault occurs on the direct current branch circuit. The system can determine the direct current branch circuit on which the insulation fault occurs in the photovoltaic power generation system, so that measures are taken in time for the direct current branch circuit on which the insulation fault occurs, to eliminate a potential safety hazard.

    DIRECT CURRENT-DIRECT CURRENT CONVERSION CIRCUIT

    公开(公告)号:US20220166313A1

    公开(公告)日:2022-05-26

    申请号:US17670592

    申请日:2022-02-14

    Abstract: A direct current-direct current conversion circuit includes: an input inductor, a first capacitor, a second capacitor, a flying capacitor, a first switch, a second switch, a first inductor, a first diode, a first buffer circuit, a third switch, a fourth switch, a second inductor, a second diode, and a second buffer circuit. A power supply, the input inductor, the first diode, the second diode, the first capacitor, and the second capacitor are sequentially connected in series. A first terminal of the flying capacitor is connected between the first diode and the second diode. A second terminal of the flying capacitor is connected between the first switch and the third switch, and the second terminal of the flying capacitor is further connected between the second switch and the second inductor.

    INVERTER, COMBINER BOX, AND PHOTOVOLTAIC SYSTEM

    公开(公告)号:US20220060146A1

    公开(公告)日:2022-02-24

    申请号:US17519291

    申请日:2021-11-04

    Inventor: Tiansan LIN Peng JU

    Abstract: Embodiments of this application disclose a design of an inverter and a design of a combiner box, to reduce maintenance costs of a photovoltaic device. According to the inverter or the combiner box provided in the embodiments of this application, when electroluminescence (EL) defect detection is performed on the photovoltaic device, a reverse charging circuit integrated into the inverter or integrated into the combiner box is used to output a direct current to a to-be-tested photovoltaic string of the photovoltaic device. Whether the to-be-tested photovoltaic string has defects is determined based on a light emission status of the to-be-tested photovoltaic string. By using the foregoing designs, maintenance engineers do not need to modify wiring terminals of the photovoltaic device when performing EL defect tests on the photovoltaic device. This helps reduce maintenance costs of the photovoltaic device.

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