| 摘要 |
FIELD: measurement equipment. ^ SUBSTANCE: invention is related to development geophysics, namely, to facilities for transmission of measurement signals from well to day surface in process of drilling. For this purpose in method of overvoltage protection of electronic circuits in bottomhole telemetric system with wireless communication channel and turbogenerator, comprising hydraulic turbine, electric generator (EG) and magnetic coupling between them, power is supplied from three-phase winding of EG to electronic circuits, and voltage is supplied from signal winding to control and communication module, comprising inverter in the form of bridge circuit (BC) with switches, controlled with the help of microcomputer and connected to electric splitter (ES), and EG rotor rotations are calculated by time intervals between two transitions of sinusoid voltage on signal winding via "zero". At the same time in case number of EG rotor rotations exceed permissible value, its signal winding is closed, and all switches are included into short-circuited electric circuit, creating braking torque by value that exceeds torque of magnetic coupling between master and slave parts of magnetic coupling of turbogenerator. As a result, they are taken out of magnetic coupling, and rotation transmission from hydraulic turbine to EG is terminated, which stops its rotation. Method is realised by bottomhole telemetric system with wireless communication channel, comprising ES, metering modules and turbogenerator, including hydraulic turbine and EG, unit of contactless transmission of rotation from hydraulic turbine shaft to EG shaft, which is arranged in the form of magnetic coupling, module of control and communication, comprising inverter in the form of BC with switches, controlled by microcomputer. At the same time arms of BC inverter are connected to signal winding of EG via current rectifier, and bridge diagonal - to ES electrodes, outlet of microcomputer is connected to inverter switches, and inlet - to signal winding of EG via circuit of detection of sinusoid voltage transitions on signal winding over "zero". Switches of inverter are included into BC with the possibility to create short-circuited electric circuit together with signal winding of EG by command of microcomputer. ^ EFFECT: improved reliability of operation and increased service life of turbogenerator and electronic circuits. ^ 2 cl, 4 dwg |
