In the spot network with multi low-voltage sources parallel supply， some sources might run with reverse power

making it impossible to ensure the system operating criteria. To solve the above problem

a power flow control method of the low-voltage bus is proposed. The law of power flow distribution is analyzed and the relation between the source output and the source voltage

system equivalent impedance and low voltage load is deduced. And the condition for reverse output is analyzed theoretically. To meet the operating condition of real-time parallel supply， the power flow control model of the low-voltage bus is proposed based on the principle of balanced source output， which gives the relationship between the source output and series compensating voltage. Finally， an experimental system is designed with the unified power flow controller (UPFC) with the validity of the proposed control method proved by experimental results.