METHOD AND APPARATUS FOR CONTROLLING POWER SUPPLY SYSTEM, AND SYSTEM

This application provides a method for controlling a power supply system, including: A controller determines that N photovoltaic strings in the power supply system meet ∑ i = 1 N P max i > P out ⋅ P max i represents maximum power point power corresponding to each of the N photovoltaic strings in a previous MPPT, and Pout represents scheduling power of an inverter unit. The controller controls a direct current voltage conversion unit to enable X photovoltaic strings in the N photovoltaic strings to be in an MPPT state, and N - X photovoltaic strings to be in a power output limited state. N ≥ 2, 1 ≤ X ≤ N - 1, and the X photovoltaic strings meet ∑ i = 1 X P max i ≤ P out . According to the method for controlling a power supply system provided in this application, in a light discarding state, power limitations of some photovoltaic strings are separately lifted, so that the photovoltaic strings perform MPPT detection. This may implement independent control on the photovoltaic strings and implement more accurate optical power prediction.