A power allocation apparatus for a plurality of power conditioning systems, wherein each of the plurality of power conditioning systems is connected to a busbar, and the apparatus comprises a reactive-voltage droop control module, a micro grid controller, a reactive-voltage differential droop control module, and a power conditioning system controller; wherein the reactive-voltage droop control module and the power conditioning system controller is each configured to connect to each power conditioning system, the micro grid controller is configured to connect to the busbar, and the power conditioning system controller is configured to separately connect to the reactive-voltage droop control module, the micro grid controller, and the reactive-voltage differential droop control module; the power conditioning system controller is further configured to: determine a first weight, a second weight, and a third weight based on an output voltage and an output current of a first power conditioning system, wherein the first weight, the second weight, and the third weight is determined based on a parameter λ measuring an error value of the reactive power of the first power conditioning system; and send the first weight to the reactive-voltage droop control module, send the second weight to the micro grid controller, and send the third weight to the reactive-voltage differential droop control module, wherein the first power conditioning system is any one of the plurality of power conditioning systems; the reactive-voltage droop control module is further configured to: collect a voltage value of the output voltage of the first power conditioning system; and determine a first reference value of a power of the first power conditioning system based on the voltage value of the output voltage of the first power conditioning system and the first weight; the micro grid controller is further configured to: collect a voltage value of an output voltage of the busbar; and determine a second reference value of the power of the first power conditioning system based on the voltage value of the output voltage of the busbar and the second weight; the reactive-voltage differential droop control module is further configured to: collect the voltage value of the output voltage of the first power conditioning system, and determine a voltage value change rate of the output voltage of the first power conditioning system based on voltage values that are of the output voltage of the first power conditioning system and that are collected at different moments; and determine a third reference value of the power of the first power conditioning system based on the voltage value change rate and the third weight; and the power conditioning system controller is further configured to determine a value of the power of the first power conditioning system based on the first reference value, the second reference value, and the third reference value. wherein the reactive-voltage droop control module and the power conditioning system controller is each configured to connect to each power conditioning system, the micro grid controller is configured to connect to the busbar, and the power conditioning system controller is configured to separately connect to the reactive-voltage droop control module, the micro grid controller, and the reactive-voltage differential droop control module; the power conditioning system controller is further configured to: determine a first weight, a second weight, and a third weight based on an output voltage and an output current of a first power conditioning system, wherein the first weight, the second weight, and the third weight is determined based on a parameter λ measuring an error value of the reactive power of the first power conditioning system; and send the first weight to the reactive-voltage droop control module, send the second weight to the micro grid controller, and send the third weight to the reactive-voltage differential droop control module, wherein the first power conditioning system is any one of the plurality of power conditioning systems; the reactive-voltage droop control module is further configured to: collect a voltage value of the output voltage of the first power conditioning system; and determine a first reference value of a power of the first power conditioning system based on the voltage value of the output voltage of the first power conditioning system and the first weight; the micro grid controller is further configured to: collect a voltage value of an output voltage of the busbar; and determine a second reference value of the power of the first power conditioning system based on the voltage value of the output voltage of the busbar and the second weight; the reactive-voltage differential droop control module is further configured to: collect the voltage value of the output voltage of the first power conditioning system, and determine a voltage value change rate of the output voltage of the first power conditioning system based on voltage values that are of the output voltage of the first power conditioning system and that are collected at different moments; and determine a third reference value of the power of the first power conditioning system based on the voltage value change rate and the third weight; and the power conditioning system controller is further configured to determine a value of the power of the first power conditioning system based on the first reference value, the second reference value, and the third reference value.