Design and Analysis of Tubular Linear PM Generator

This paper presents a successful design of a tubular synchronous linear PM generator (TSLPG) as a heating equipment to prevent paraffin deposition in the oil well. Due to its requirement, a large air-gap configuration without power supply is adopted and the copper layer is used directly to produce eddy current power. In order to obtain the maximum power density, a two-dimensional dynamic FEM model is developed to investigate the performance of TSLPG with different magnetized magnets and structure parameters. By comparing radially magnetized and axially magnetized structures, it is found that TSLPG with radially magnetized magnets has higher power density. Furthermore, the optimal pole pitch and copper layer thickness are identified. The predicted results are validated experimentally. It shows that the developed prototype TSLPG can produce enough eddy current power to solve the problem of paraffin deposition inside the oil tube.