SJDE-01APA

SJDE-02APA

SJDE-04APA

SJDE-04APA+SJME-04AMB41

SJDE-08APA

SJME-01AMA41

SJME-04AMA41

SJME-04AWA41

SJME-08AWA41

The AC induction motor vector control application utilizes four channels of the Quad Timer module for position and speed sensing. A fifth channel of the Quad Timer module is set to generate a time base for speed sensing and a speed controller. The Quadrature Decoder is a module providing decoding of position signals from a Quadrature Encoder mounted on a motor shaft. It has the following features: • Includes logic to decode quadrature signals • Configurable digital filter for inputs • 32-bit position counter • 16-bit position difference counter • Maximum count frequency equals the peripheral clock rate • Position counter can be initialized by software or external events • Preloadable 16-bit revolution counter • Inputs can be connected to a general purpose timer to aid low speed velocity. The AC induction motor vector control application utilizes the Quadrature Decoder connected to Quad Timer module B. It uses the decoder’s digital input filter to filter the encoder’s signals, but does not make use of its decoding functions, freeing the decoder’s digital processing capabilities to be used by another application.

The AC induction motor is a rotating electric machine designed to operate from a 3-phase source of alternating voltage. For variable speed drives, the source is normally an inverter that uses power switches to produce approximately sinusoidal voltages and currents of controllable magnitude and frequency. A cross-section of a two-pole induction motor is shown in Figure 3-1. Slots in the inner periphery of the stator accommodate 3-phase winding a,b,c. The turns in each winding are distributed so that a current in a stator winding produces an approximately sinusoidally-distributed flux density around the periphery of the air gap. When three currents that are sinusoidally varying in time, but displaced in phase by 120° from each other, flow through the three symmetrically-placed windings, a radially-directed air gap flux density is produced that is also sinusoidally distributed around the gap and rotates at an angular velocity equal to the angular frequency, ωs, of the stator currents. The most common type of induction motor has a squirrel cage rotor in which aluminum conductors or bars are cast into slots in the outer periphery of the rotor. These conductors or bars are shorted together at both ends of the rotor by cast aluminum end rings, which also can be shaped to act as fans. In larger induction motors, copper or copper-alloy bars are used to fabricate the rotor cage winding.