The invention discloses a distributed photovoltaic
voltage out-of-limit treatment method for calculating
line loss, and the method comprises the steps: calculating an active power instruction and a reactive power instruction which should be injected into a grid-connected point by a
photovoltaic power generation system when the
voltage of the grid-connected point is under an out-of-
limit value level when the
voltage detection result of the grid-connected point is out of limit; performing coordinate transformation on the modulation
signal, performing constant amplitude transformation on the voltage of the grid-connected point, and directionally
synchronizing the voltage of the grid-connected point into a rotating coordinate
system to obtain a current reference value on a d-q coordinate axis; a current reference value on a d-q coordinate axis and an actual value are subjected to difference
processing and sent to a
PI regulator, a modulation
signal obtained after coordinate
system transformation is subjected to SVPWM modulation, an output
signal obtained after modulation serves as a
control signal of a photovoltaic grid-connected
inverter, active power and reactive power of a photovoltaic injection grid-connected point are further adjusted so as to adjust the voltage of the grid-connected point, and the voltage of the grid-connected point is adjusted. The
bus of the power distribution network can receive the maximum active power, so that the
line loss is reduced, and the energy waste is avoided.