Circulation protection method and device, electronic equipment and readable memory

Abstract

The invention discloses a circulating current protection method. The method comprises the following steps: acquiring circuit parameter information of a combiner box; obtaining a theoretical output voltage of the combiner box based on the circuit parameter information, and judging whether a difference value between the theoretical output voltage and an actual output voltage of the combiner box is greater than a first preset threshold value or not; under the condition that the difference value between the theoretical output voltage and the actual voltage is larger than a first preset threshold value, the average current of each path of group string in the combiner box and the theoretical power of the combiner box are obtained based on the circuit parameter information, and whether the difference value between the theoretical power and the actual power exceeds a second preset threshold value or not is judged; and under the condition that the difference value between the theoretical power and the actual power exceeds a second preset threshold value, outputting a string abnormity result. According to the invention, real-time monitoring and early warning are carried out on the abnormal circulation, when the abnormal circulation occurs, a fault alarm is given in time, and the risk of damage to components and related equipment is reduced.

Description

technical field [0001] The invention belongs to the technical field of photovoltaic electrical equipment, and in particular relates to a circulating current protection method, device, electronic equipment and readable memory. Background technique [0002] At present, in order to improve the efficiency of the DC current output of the photovoltaic power generation system, the output voltage of the combiner box is increased in design, and the common method is to increase the number of components connected in series at the input end, thereby reducing the output current of the DC side and reducing the loss on the line. Increasing the number of modules connected in series and increasing the DC output voltage is beneficial to improve the working efficiency of the system, but there are also certain hidden dangers to the operation of the combiner box. When there is a fault or external influence, the input voltage drops, and a voltage deviation occurs in the parallel string circuit, w...

AI Technical Summary

Problems solved by technology

Increasing the number of modules connected in series and increasing the DC output voltage is beneficial to improve the working efficiency of the system, but there are also certain hidden dangers to the operation of the combiner box. When there is a fault or is affected by the outside world, the input voltage drops, and a voltage deviation occurs in the parallel string circuit, which in turn generates circuit current circulation, causing some components to heat up and reducing the output voltage of the combiner box

[0003] Under normal circumstances, there is a small difference in the voltage between different strings of confluence, because the internal resistance of the string is small, and the internal heat of the photovoltaic module caused by the current circulation inside is small, but if the performance of the module fails, the output voltage will drop significantly. When the temperature is high, the circuit circulation will increase, the loss and heat will increase, and in severe cases, the components will be burned, and even a fire will occur at the junction box of the component or the inlet and outlet of the combiner box.

Images