CENTRALIZED MPPT EXITING AND SWITCHING METHOD AND APPLICATION THEREOF
First Claim
1. A method for exiting a MPPT centralized mode of a photovoltaic inverter, wherein the photovoltaic inverter comprises a plurality of DC chopper circuits and an inverting circuit, and the inverting circuit is connected to an output side of the plurality of DC chopper circuits on which side the plurality of DC chopper circuits are connected in parallel to a DC bus, the method comprising:
- performing a MPPT control individually on each of photovoltaic strings to obtain a maximum power point for each of the photovoltaic strings, when the photovoltaic inverter is operating in the MPPT centralized mode, wherein the photovoltaic strings are connected in parallel to the DC bus via DC chopper circuits which stop operating;
determining a standard value for the maximum power points of the photovoltaic strings according to the type of the plurality of DC chopper circuits; and
determining whether voltage differences between voltages of the maximum power points and the standard value exceed a preset voltage difference, and restarting DC chopper circuits connected to photovoltaic strings with voltage differences exceeding the preset voltage difference.
1 Assignment
0 Petitions
Accused Products
Abstract
Disclosed is a centralized MPPT exiting method for a photovoltaic inverter comprising multiple DC chopper circuits and one inverter circuit. The method comprises: when the photovoltaic inverter is in a centralized MPPT mode, MPPT control is implemented independently for each photovoltaic cell in a photovoltaic component and the maximum power point for each photovoltaic cell is obtained; a reference value of the maximum power point for each photovoltaic cell is determined according to the type of the multiple DC chopper circuits; whether the voltage difference between the other maximum power points and the reference value goes beyond an allowable voltage difference is judged and the operation of the DC chopper circuits connecting to the photovoltaic cells with a voltage difference beyond the allowable voltage difference is recovered.
-
Citations
20 Claims
-
1. A method for exiting a MPPT centralized mode of a photovoltaic inverter, wherein the photovoltaic inverter comprises a plurality of DC chopper circuits and an inverting circuit, and the inverting circuit is connected to an output side of the plurality of DC chopper circuits on which side the plurality of DC chopper circuits are connected in parallel to a DC bus, the method comprising:
-
performing a MPPT control individually on each of photovoltaic strings to obtain a maximum power point for each of the photovoltaic strings, when the photovoltaic inverter is operating in the MPPT centralized mode, wherein the photovoltaic strings are connected in parallel to the DC bus via DC chopper circuits which stop operating; determining a standard value for the maximum power points of the photovoltaic strings according to the type of the plurality of DC chopper circuits; and determining whether voltage differences between voltages of the maximum power points and the standard value exceed a preset voltage difference, and restarting DC chopper circuits connected to photovoltaic strings with voltage differences exceeding the preset voltage difference. - View Dependent Claims (2, 3, 4, 5, 6, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
-
-
7. An apparatus for exiting a MPPT centralized mode of a photovoltaic inverter, wherein the photovoltaic inverter comprises a plurality of DC chopper circuits and an inverting circuit, and the inverting circuit is connected to an output side of the plurality of DC chopper circuits on which side the plurality of DC chopper circuits are connected in parallel to a DC bus, the apparatus comprising:
-
a maximum power point determination unit, configured to perform a MPPT control individually on each of photovoltaic strings to obtain a maximum power point for each of the photovoltaic strings when the photovoltaic inverter is operating in the MPPT centralized mode, wherein the photovoltaic strings are connected in parallel to the DC bus via DC chopper circuits which stop operating; a standard value determination unit connected with the maximum power point determination unit, configured to determine a standard value for the maximum power points of the photovoltaic strings according to the type of the plurality of DC chopper circuits; and a circuit restarting unit connected with the standard value determination unit, configured to determine whether voltage differences between voltages of the maximum power points and the standard value exceed a preset voltage difference, and restart DC chopper circuits connected to photovoltaic strings with voltage differences exceeding the preset voltage difference. - View Dependent Claims (8)
-
-
9. An inverter control system for a photovoltaic inverter, wherein the photovoltaic inverter comprises a plurality of DC chopper circuits and an inverting circuit, and the inverting circuit is connected to an output side of the plurality of DC chopper circuits on which side the plurality of DC chopper circuits are connected in parallel to a DC bus, wherein, the control system is configured to, when the photovoltaic inverter is operating in a MPPT centralized mode, perform a MPPT control individually on each of photovoltaic strings to obtain a maximum power point for each of the photovoltaic strings, wherein the photovoltaic strings are connected in parallel to the DC bus via DC chopper circuits which stop operating;
- determine a standard value for the maximum power points of the photovoltaic strings according to the type of the plurality of DC chopper circuits; and
determine whether voltage differences between voltages of the maximum power points and the standard value exceed a preset voltage difference, and restart DC chopper circuits connected to photovoltaic strings with voltage differences exceeding the preset voltage difference. - View Dependent Claims (10)
- determine a standard value for the maximum power points of the photovoltaic strings according to the type of the plurality of DC chopper circuits; and
Specification