Method For Controlling Operation Of MLPE Device, Method For Controlling MLPE Devices, and Photovoltaic System
AssigneeSungrow Power Supply Co., Ltd.
InventorsYanfei YU, Anying JIANG, Yu YANG, Xiaoxun LI
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Abstract
Provided are a method for controlling operation of a module level power electronics (MLPE) device, a method for controlling MLPE devices and a photovoltaic system. In the method for controlling operation of a MLPE device, if it is determined that a current of a photovoltaic string where the MLPE device is located is less than a current threshold and coding information sent by a converter in the photovoltaic system is not received for a first preset time period, an output voltage or an output power of the MLPE device is controlled to be less than a corresponding threshold.
Claims14
A method for controlling operation of a module level power electronics (MLPE) device, the method applied to the MLPE device, the MLPE device comprising a switching device connected in series with a photovoltaic module corresponding to the MLPE device, and the method comprising:
- detecting a current of a photovoltaic string where the MLPE device is located;
- determining whether the current of the photovoltaic string is less than a current threshold and coding information sent by a converter in a photovoltaic system is not received for a first preset time period;
- and
- controlling, if it is determined that the current of the photovoltaic string is less than the current threshold and the coding information sent by the converter is not received for the first preset time period, an output voltage or an output power of the MLPE device to be less than a corresponding threshold.
A method for controlling module level power electronics (MLPE) devices, the method being applied to a converter of a photovoltaic system, wherein a former circuit of the converter is connected with at least one photovoltaic string, each photovoltaic string comprises a plurality of photovoltaic modules connected in series with each other via the MLPE devices corresponding to the photovoltaic modules, the method comprises:
- periodically determining whether an input voltage of the converter is less than a fourth preset voltage threshold;
- continuously generating and outputting, if the input voltage of the converter is less than the fourth preset voltage threshold, coding information to each of the MLPE devices in the former circuit of the converter, to cause each of the MLPE devices to be in a normal operation state;
- and
- stopping generating the coding information, if the input voltage of the converter is greater than or equal to the fourth preset voltage threshold, to cause an output voltage or an output power of each of the MLPE devices to be less than a corresponding threshold.
A photovoltaic system comprising a converter and a photovoltaic array in a former circuit of the converter, wherein
- the photovoltaic array comprises at least one photovoltaic string, each photovoltaic string comprises a plurality of photovoltaic modules connected in series with each other via module level power electronics (MLPE) devices corresponding to the photovoltaic modules;
- each MLPE device comprises a switching device connected in series with the photovoltaic module corresponding to the MLPE device;
- each MLPE device is configured to perform a method for controlling operation of the MLPE device comprising:
- detecting a current of a photovoltaic string where the MLPE device is located;
- determining whether the current of the photovoltaic string is less than a current threshold and coding information sent by the converter in the photovoltaic system is not received for a first preset time period;
- and
- controlling, if it is determined that the current of the photovoltaic string is less than the current threshold and the coding information sent by the converter is not received for the first preset time period, an output voltage or an output power of the MLPE device to be less than a corresponding threshold;
- and
- the converter is configured to perform a method for controlling MLPE devices comprising:
- periodically determining whether an input voltage of the converter is less than a fourth preset voltage threshold;
- continuously generating and outputting, if the input voltage of the converter is less than the fourth preset voltage threshold, coding information to each of the MLPE devices in a former circuit of the converter, to cause each of the MLPE devices to be in a normal operation state;
- and
- stopping generating the coding information, if the input voltage of the converter is greater than or equal to the fourth preset voltage threshold, to cause an output voltage or an output power of each of the MLPE devices to be less than a corresponding threshold.
Dependencies are inferred from the claim text.