有载分接开关（oltc）在电力系统中调节无功功率和稳定电网电压方面起着

On-load tap changer (oltc) plays an important role in regulating reactive power and stabilizing grid voltage in the power system [1]. According to statistics, on-load tap-changing transformer faults account for more than 20% of total faults, and mechanical faults account for more than 90% of total faults [2]. In recent years, with the rapid application of electric vehicles (EV), supporting charging piles and energy storage devices have been incorporated into the power grid [3], these components inevitably incorporate new features and challenges into the traditional power grid. When a large number of different electric vehicles converge and the charging behavior at different access levels will affect the grid voltage level. The voltage change will directly affect the current change. When the power grid is operating under low voltage, it will cause the reactive power and active power of the power grid to increase, thereby increasing the cost. The frequent voltage regulation operation of the OLTC can improve the quality of the power grid, and the relative OLTC failures are also increasing. Therefore, it is necessary to design an effective method for extracting the mechanical characteristics of on-load tapping transformers. The purpose of this method is to find hidden dangers in the operation of the on-load tap changer of the smart grid of electric vehicles as early as possible. This early warning mechanism is of great significance to ensure the reliable operation of the transformer [4].

The on-load tap switch (oltc) plays an important role in regulating reactive power and stabilizing grid voltage in the power system. According to statistics, there are load-bearing regulator failure accounted for more than 20% of the total failure, mechanical failure accounted for more than 90% of the total failure. In recent years, with the rapid application of electric vehicles (EVs), equipment such as charging piles and energy storage devices have been incorporated into the grid, and these components have inevitably incorporated new features and challenges into the traditional grid. When a large number of different electric vehicle convergence, as well as different access levels of charging behavior, will affect the level of grid voltage. The change of voltage will directly affect the change of current, the power grid in low voltage, will lead to the power grid reactive power, active power increased, and thus increase the cost. Through the frequent voltage regulation operation of OLTC, the quality of the power grid can be improved, and the fault of the relative OLTC is also increasing. Therefore, it is necessary to design an effective mechanical characteristic extraction method of load-load regulator transformer. The purpose of this method is to find the hidden dangers in the operation of the load tap switch in the smart grid of electric vehicles as soon as possible. This early warning mechanism is of great significance to ensure the reliable operation of transformers.

On load tap changer (OLTC) plays an important role in regulating reactive power and stabilizing grid voltage in power system [1]. According to statistics, on load tap changer faults account for more than 20% of the total faults, and mechanical faults account for more than 90% of the total faults [2]. In recent years, with the rapid application of electric vehicles (EV), the matching charging piles and energy storage devices have been incorporated into the power grid [3]. These components inevitably bring new features and challenges to the traditional power grid. When a large number of different EV convergence, as well as the charging behavior under different access levels, will affect the level of grid voltage. The change of voltage will directly affect the change of current. When the power grid operates under the condition of low voltage, it will lead to the increase of reactive power and active power, and then increase the cost. Through frequent voltage regulation of OLTC, the quality of power grid can be improved, and the fault of OLTC is also increasing. Therefore, it is necessary to design an effective method to extract the mechanical characteristics of on load tap changer. The purpose of this method is to find out the hidden trouble in the operation of on load tap changer in electric vehicle smart grid as soon as possible. This early warning mechanism is of great significance to ensure the reliable operation of transformer [4].