AD2S100 Datasheet, PDF (1/12 Pages) Analog Devices – AC Vector Processor

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AC Vector Processor
AD2S100
FEATURES
Complete Vector Coordinate Transformation on Silicon
Mixed Signal Data Acquisition
Three-Phase 120؇ and Orthogonal 90؇ Signal
Transformation
Three-Phase Balance Diagnostic–Homopolar Output
APPLICATIONS
AC Induction and DC Permanent
Magnet Motor Control
HVAC, Pump, Fan Control
Material Handling
Robotics
Spindle Drives
Gyroscopes
Dryers
Washing Machines
Electric Cars
Actuator
Three-Phase Power Measurement
Digital-to-Resolver & Synchro Conversion
GENERAL DESCRIPTION
The AD2S100 performs the vector rotation of three-phase 120
degree or two-phase 90 degree sine and cosine signals by trans-
ferring these inputs into a new reference frame which is controlled
by the digital input angle φ. Two transforms are included in the
AD2S100. The first is the Clarke transform which computes
the sine and cosine orthogonal components of a three-phase
input. These signals represent real and imaginary components
which then form the input to the Park transform. The Park
transform relates the angle of the input signals to a reference
frame controlled by the digital input port. The digital input
port is a 12-bit parallel binary representation.
If the input signals are represented by Vds and Vqs, respectively,
where Vds and Vqs are the real and imaginary components, then
the transformation can be described as follows:
Vds' = Vds Cosφ – Vqs Sinφ
Vqs' = Vds Sinφ + Vqs Cosφ
Where Vds' and Vqs' are the output of the Park transform
and Sinφ, and Cosφ are the values internally derived by the
AD2S100 from the binary digital data.
The input section of the device can be configured to accept
either three-phase inputs, two-phase inputs of a three-phase
system, or two 90 degree input signals. The homopolar output
detects the imbalance of a three-phase input only. Under nor-
mal conditions, this output will be zero.
FUNCTIONAL BLOCK DIAGRAM
Cosθ Sinθ
INPUT
DATA
STROBE
φ POSITION
PARALLEL
DATA
12 BITS
Ia
Cosθ
Ib
Cos (θ + 120°)
Cos (θ + 240°) ^Ic
Sinθ
SINE AND
SECTOR _COSINE
Vds ^{MULTIPLIER MULTIPLIER}
30-20
Vqs
SECTOR
MULTIPLIER
SINE AND
COSINE
MULTIPLIER
BUSY
Vds'
2φ -3φ
Vqs'
Va _{Cos θ + φ}
Vb _{Cos (θ + 120° + φ)}
Vc _{Cos (θ + 240° + φ)}
Sin θ + φ
CONV1
CONV2
DECODE
Ia + Ib + Ic
3
HOMOPOLAR HOMOPOLAR +5V GND –5V
OUTPUT
REFERENCE
The digital input section will accept a resolution of up to 12 bits
(AD2S100). An input data strobe signal is required to synchro-
nize the position data and load this information into the device
counters. A busy output is provided to identify the conversion
status of the AD2S100. The busy period represents the conver-
sion time of the vector rotation.
Two analog output formats are available. A two-phase rotated
output facilitates multiple rotation blocks. Three phase format
signals are available for use with a PWM inverter.
PRODUCT HIGHLIGHTS
Hardware Peripheral for Standard Microcontrollers and
DSP Systems
The AD2S100 removes the time consuming cartesian transfor-
mations from digital processors and benchmarks a speed im-
provement of 30:1 on standard 20 MHz processors. AD2S100
transformation time = 2 µs (typ).
Field Oriented Control of AC and DC Brushless Motors
The AD2S100 accommodates all the necessary functions to
provide a hardware solution for ac vector control of induction
motors and dc brushless motors.
Three-Phase Imbalance Detection
The AD2S100 can be used to sense overcurrent situations or
imbalances in a three-phase system via the homopolar output.
Resolver-to-Digital Converter Interface
The AD2S100 provides general purpose interface for position
sensors used in the application of dc brushless and ac induction
motor control.
REV. A
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