Simulation and Experiment Research on Performance of High Power While-drilling Turbine Generator

To resolve the limitations of downhole turbine generators, such as insufficient power generation, low adaptability of output voltage, and complicated testing of directional drilling tools, the performance study of a turbine generator with high-power capacity and magnetic field excitation was conducted. Based on the Simulink model of the turbine generator and excitation control system, the excitation control system and hardware circuit were designed according to the voltage management requirement of the tool. The external characteristics of the generator at different speeds and loads, the excitation control circuit board's real-time excitation current regulation performance, and the overall closed-loop control performance were simulated and tested. The results show that the model effectively verifies the feasibility of the excitation control principle, the model and prototype version have similar characteristics, and the model can accurately match the prototype. The output voltage range meets the regular operation of directional drilling tools, and the output power can reach 4kW within the rated speed of 6000r/min. The designed excitation regulation system model and hardware circuit meet the tool power management requirements, and the excitation voltage regulation rate is about ±20%. This study solves the relationship between mud flow rates and output power and intuitively guides actual drilling operations and workshop maintenance. As a result, this research can reduce the testing cost and complexity of directional drilling tools.