| CPC H02J 3/46 (2013.01) [H02J 3/0075 (2020.01); H02J 3/01 (2013.01); H02J 2300/26 (2020.01)] | 20 Claims |

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1. A power conversion apparatus, comprising:
a first direct current conversion circuit having an input end configured to connect to a first photovoltaic string;
a second direct current conversion circuit having an input end configured to connect to a second photovoltaic string, wherein an output end of the first direct current conversion circuit and an output end of the second direct current conversion circuit are connected in parallel to a direct current bus; and
a control circuit configured to, in response to an output voltage of the first photovoltaic string being greater than an output voltage of the second photovoltaic string and a comparison value between the output voltage of the first photovoltaic string and the output voltage of the second photovoltaic string being greater than a first threshold:
control a switching transistor in the first direct current conversion circuit to be turned on or off to decrease the output voltage of the first photovoltaic string and a switching transistor in the second direct current conversion circuit to be turned on or off to increase the output voltage of the second photovoltaic string, so that a comparison value between the output voltage of the second photovoltaic string and a bus voltage of the direct current bus is less than a second threshold.
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