In order to reduce network loss

balance load and improve reliability

it is necessary to adjust the structure of the distribution network.The traditional manual way of verifying and maintaining the topology is time consuming and labor intensive.The huge operation data which are produced by power grid

such as bus voltage and outlet voltage of distribution transformer

can indirectly reflect the topology of distribution network.So

we propose a substation area topology verification method based on distribution network operation data

which includes the reduction method of transformer’s outlet voltage when three-phase load is unbalanced.The correlation coefficient between the substation area’s voltage curves is calculated.The topology is verified by the value of correlation coefficient.Meanwhile

the estimation method which can be used to distinguish which substation and which 10 kV line the substation area belongs to is also put forward.An example of topology verification distribution network is given in this paper.The results show that the reduction method of transformer’s outlet voltage proposed in this paper can be used to calculate three-phase unbalanced transformer’s outlet voltage if the transformer load is three-phase balanced.This method can overcome the volatility and error when using single-phase voltage curve to calculate correlation coefficient and improve the accuracy of topology verification.The estimation method

which can be used to distinguish which 10 kV line the substation area belongs to

is effective to distinguish the different 10 kV lines in one substation and the accuracy rate is 91.7%.The substation area topology verification method proposed in this paper can be programmed and used to analyze the huge operation data.The problem of time consuming and labor intensive of manual way can be solved.