User's Manual

PMAC2 User Manual
Setting Up PMAC2 for Sine-Wave Output Control 33
SETTING UP PMAC2 FOR SINE-WAVE OUTPUT CONTROL
How to Set up the Commutation Scheme
This section explains how to set up the commutation scheme if PMAC2 is performing the commutation
for a motor, but not the digital current loop. In this mode, PMAC2 outputs two phase current commands
to the amplifier, usually as analog voltages through digital-to-analog converters (DACs). In the steady-
state, these voltages are a sinusoidal function of time, so this mode is often called sine-wave output.
Hardware Setup
For PMAC2 to operate a motor in the sine-wave commutation analog output mode, an Acc-8E analog
interface board or equivalent must be attached to the machine connector for the machine interface channel
used. The Acc-8E board contains the DACs, output op-amps, encoder and flag interfaces, and optical
isolation circuits. The following discussion assumes an Acc-8E is being used.
DAC Output Signals
The DACA and DACB outputs on the Acc-8E should be connected to the phase command inputs on the
sine-wave input amplifier. If the inputs on the amplifier are single-ended, use the DAC+ output only, and
leave the complementary DAC- outputs floating; do not ground them. If the inputs on the amplifier are
complementary, use both the DAC+ and DAC- outputs. In either case, tie the AGND reference voltage
on the Acc-8E to the reference voltage for the amplifier input.
+
+
Magnetization
Current
Ix77
Torque Command
from Position/
Velocity Servo
Direct Current
Command
Quadrature
Current Command
dq
to
abc
DAC
I
q
I
d
I
b
I
a
DAC
PI
PI
V
b
V
a
PWM
PWM
I
a
I
b
Phase A Current Loop
Phase B Current Loop
PWM
V
c
Balance Loop
v
c
v
b
v
a
+
-
-
-
-
-
-
-
'
'
'
'
PMAC
A
MPLIFIER
E
Q
Figure 12 PMAC/PMAC2 Commutation with Analog Loop
Amplifier Enable and Fault Interface
The amplifier enable outputs on the Acc-8E use dry-contact relays. Normally-open, normally closed,
sinking or sourcing configurations from 12V to 24V can be chosen.
The amplifier fault inputs on the Acc-8E pass through AC Opto isolators. Sinking or sourcing
configurations from 12V to 24V can be chosen.
Encoder Feedback
The Acc-8E can accept 3-channel quadrature encoder feedback, either single-ended or differential, in the
range of 5V to 12V.