Hitachi Vector Control with the SJ300 Inverter User Manual

[1] Overview
This engineering note applies when using SLV , 0-SLV and V2 (closed loop) control. It is often difficult to
get optimized motor performance because many parameters interact. Please refer to this document for
getting a rough idea how to achieve good motor performance with above control modes. Please also note that
the performance WILL NOT BE like a servo drive even in the case of V2 mode.
There are 3 basic modes with which you can get high torque performance with the SJ300 inverter:
(1) SLV control (No SJ-FB is used)
High motor torque performance with open loop can be obtained in the low frequency range (~0.5Hz).
Please refer to a standard SLV block diagram in Fig 1 (section 2-2).
[H***] parameters are mainly adjusted for the control.
(2) 0-SLV control (No SJ-FB is used)
High torque performance can be obtained at around 0Hz. This does NOT mean the motor shaft will be at a
standstill. The motor rotates slightly to generate motor torque, since this is not a servo drive. Depending on the
application and tuning, you may be able to get full torque with the motor at standstill. This control algorithm is
different from SLV control.
[H***] parameters are mainly adjusted for the control.
ΠFrequency control block portion
• Voltage control block portion
(3) V2 control (SJ-FB is used)
High torque and stable, accurate motor performance can be achieved with the SJ300 in vector mode.
A motor encoder and a feedback option card for SJ300 (SJ-FB) are needed to use this control mode.
There are two regulation modes within the V2 control mode: ASR mode and APR mode .
ΠASR mode : Inverter is controlled by speed command input (digitally set, analog input, or RS485)
• APR mode : Inverter is controlled by pulse train input signal
[H***] and [P***] parameters are adjusted for achieving good motor control.
A suitable mode should be selected depending on the application.
ASR
(PI)
Slip reference
Frequency
reference
ω
r
*
+
-
q axis current
reference
+
+
Slip reference
at 0Hz
I
q
*
ω
s
+
+
ω
s
*
Speed
estimation
Change over
of control
ω
r
^
+
+
Stability
control
1/s
ω
1
Output frequency
Output phase
d-axis current
reference
Magnetizing current
i
d
*
+
-
i
d
**
d-axis
ACR
q-axis
ACR
+
-
Torque current
i
q
*
i
q
i
d
Feedback current
∆E
d
∆V
d
Estimation of
q-axis flux
Estimation of
Motor torque
+
+
calculation of
Voltage Vector
i
d
ω
1
i
q
+
+
∆V
q
V
d
*
V
q
*
V
d
V
q
Output
voltage
Estimation of
Flux

Hitachi Vector Control with the SJ300 Inverter Specifications

General

Brand	Hitachi
Model	Vector Control with the SJ300 Inverter
Category	Inverter
Language	English