Torque-sensing control system for a brushless doubly fed machine (BDFM)

摘要

The machine comprises a brushless doubly fed motor or generator (BDFG), a controller coupled to an ac mains power supply line connection, and a rotor speed sensor coupled to said controller. The controller has inputs for a current signal and a voltage signal from the power and control stator windings, and from the rotation sensor. A first control module generates a torque demand signal from angular rotation speed data and information defining a target angular rotation speed of said rotor. A torque estimation module generates a torque estimate from current and voltage from said power and control stator windings, said estimate being dependent on a resistance torque being applied by said generator. A second control module receives said torque demand signal and said torque estimation signal and having a quadrature voltage control output. A voltage reference frame conversion module receives said quadrature voltage and l transforms a reference frame of said quadrature and direct voltage signals to a reference frame of said control stator winding. A control stator winding driver for providing a three phase drive to said control stator winding accordingly. This control system is said to improve open-loop stability. A power factor correction system is also discussed.