ABB DO880-1 Analog module industrial system controller

Description

Packaging details: if you need an urgent delivery order, please feel free to contact us, and we will do our best to meet your needs.

Price problem: if you find that other suppliers offer cheaper prices for the same product, we are also willing to provide you with reference prices and give you further discounts.

This is a significant advance over all other AC drive technology.
The motor model is, in fact, key to DTC’s unrivalled low speed
performance.
The motor model outputs control signals which directly represent
actual motor torque and actual stator flux. Also shaft speed is
calculated within the motor model.
Step 3 Torque comparator and flux comparator
The information to control power switches is produced in the
torque and flux comparator.
Both actual torque and actual flux are fed to the comparators
where they are compared, every 25 microseconds, to a torque
and flux reference value. Torque and flux status signals are calculated using a two level hysteresis control method.
These signals are then fed to the optimum pulse selector.
Step 4 Optimum pulse selector
Within the optimum pulse selector is the latest 40 MHz digital
signal processor ( DSP) together with ASIC hardware to determine
the switching logic of the inverter. Furthermore, all control signals
are transmitted via optical links for high speed data transmission.
This configuration brings immense processing speed such that
every 25 microseconds the inverter’s semiconductor switching
devices are supplied with an optimum pulse for reaching, or
maintaining, an accurate motor torque.
The correct switch combination is determined every control
cycle. There is no predetermined switching pattern. DTC has
been referred to as “just-in-time” switching, because, unlike
traditional PWM drives where up to 30 percent of all switch
changes are unnecessary, with DTC each and every switching
is needed and used.
This high speed of switching is fundamental to the success of
DTC. The main motor control parameters are updated 40,000
times a second. This allows extremely rapid response on the
shaft and is necessary so that the motor model (see step 2) can
update this information.
It is this processing speed that brings the high performance figures including a static speed control accuracy, without encoder,
of ±0.5 percent and the torque response of less than 2 ms