The Research Of Transformer's Overload Capacity Improvement

With the rapid development of national economy, power load increases rapidly and continuedly, however, the construction of power grid is lagging behind, which leads to the high loads of the power transformers. The overload ability of power transformer limits the development of the power grid. If the power transformers has high overload capacity, it can avoid destroying power transfomers itself, and it can set aside some time to the control centre. For a long time, we use curves based on the normal data to decide the overload ability of the power transformer, but different high-capacity transformers has different abilities. This thesis studied the overload ability of power transformers, discussed it from these aspects:1,The thesis presents the theory of overload capacity of transformers, analyzing the impact and risk when transformers overload, and it considers the heatgeneration and dissipation of transformers principally. When a transformer overload, it will impact it's temperature of the oil and winding. We should develop a reasonable boundary conditions to account the ability of overload capacity of transformers.2,Based on the technical parameters,temperature rise test results and accounting boundary conditions of transformers in operation, we use the accounting model to check the overload capacity of transformers. And we can use the results to guide the draw up of the limits of transformers operation, and hope it can release the capacity of transformers。3,This thesis studies the impact of distribution equipment made by the overload of transformers, including equipments'carrying capacity and conductors'carrying capacity, analyzing the constraints and possible adverse responses. This thesis analyzes the impact of the relay protection when transformers overload, as well as measures taken in response.4,This thesis discuss the impact of the power grid planning when power transformers overload, and it also discuss the limits of running power transformers and delay the expansion of power grid based on grid requirements.