Digital vector control algorithm for induction motor torque drive
ABSTRACT High quality precision digital vector control for standard AC drive (induction motor, voltage source inverter, current and speed sensors (or mechanical variable observer)), microprocessor-based controller is described. The synthesis of control algorithm is based on using exact (analytical) discrete model; digital, independent estimation of unmeasured variables; decomposition of vector control on two independent scalar controls of the field current and torque one; using discrete sliding modes control or asymptotic control; using variables predictor on a step of calculations for compensation of delay caused by calculation time of the controller; using optimal vector PWM for reduction of switching losses. The simulation has confirmed essential increase of dynamic accuracy, simplification of algorithm of digital control, reduction of the requirements to computing capacity of the controller.
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ABSTRACT: The work is intended to explain the basic ideas related to design of digital remote control system for the oil-drowned pump. The control system must allow the pump operating very reliably under heavy conditions. The digital control system has a hierarchy local-distribute structure. The upper level is a ground control. The low level is a local-distribute control system, which has four drive controls. With the aim to reduce the cost of the drive and to increase reliability the sensorless pump drive is designed. Original observation algorithms of both position and rotational velocity for exterior permanent magnet synchronous motors are designed. The system simulation has confirmed high dynamic accuracy and in addition simplification of algorithm of digital control, reduction of the requirements to computing capacity of the controller.