Hitachi Sj7002 Owners Manual

Setting Motor Constants for Vector Control
Operations
and Monitoring
4–70
The inverter has three separate motor constant sets named  1st, 2nd, and  3rd. The 1st motor 
constant set is the default, while the SET and  SET2 intelligent inputs select the 2nd and 3rd 
constant sets, respectively. The torque control  methods are valid to use only if a particular 
motor constant set includes parameters for th e selected control method. The following table 
lists the vector control methods and shows the ones...

SJ7002 Inverter
Operations
and Monitoring
4–71
Auto-tuning of 
Motor ConstantsThe SJ7002 inverter features auto-tuning, which detects and records the motor characteristic 
parameters to use in all vector control mode s. Auto-tuning determines the resistance and 
inductance of motor windings. Therefore, the moto r must be connected to the inverter for this 
procedure. Note that the auto-tuning feature is  not associated with PID loop operation, which is 
common on some control devices. The auto-tuning...

Setting Motor Constants for Vector Control
Operations
and Monitoring
4–72
Preparation for Auto-tuning Procedure –  Be sure to study the preparation items and verify 
the related inverter configuration befo re going further in this procedure.
1. Adjust the motor base frequency (A003) and th e motor voltage selection (A082) to match 
the specifications of the motor used in the auto-tuning procedure.
2. Verify that the motor is not more than one fra me size smaller than the rated size for he 
inverter....

SJ7002 Inverter
Operations
and Monitoring
4–73
If the auto-tuning procedure is  successful, the inverter updates 
the motor characteristic parameters and indicates normal termi-
nation  of the procedure as shown. Pressing any key on the 
keypad will clear the result from the display.
 Trip during auto-tuning –  A trip event will cause the auto-
tuning sequence to quit . The display will show the error code 
for the trip rather than the ab normal termination indication. 
After eliminating the cause of the...

Setting Motor Constants for Vector Control
Operations
and Monitoring
4–74
Manual Setting of 
Motor ConstantsWith vector control, the inverter uses the output  current, output voltage, and motor constants to 
estimate the motor torque and speed. It is possibl e to achieve a high starting torque and accurate 
speed control at low frequency
 Sensorless Vector Control –  improved torque control at output  frequencies down to 0.5 Hz. 
Use A044=03 (1st motor) or A244=03 (2nd motor) to select sensorless vector...

SJ7002 Inverter
Operations
and Monitoring
4–75
PID Loop Operation
In standard operation, the inverter uses a refe rence source selected by parameter A001 for the 
output frequency, which may be a fixed value (F 001), a variable set by the front panel potenti-
ometer, or value from an analog input (voltage or  current). To enable PID operation, set A071 = 
01. This causes the inverter to calculate  the target frequency, or setpoint. An optional intelligent 
input assignment (code 23), PID Disable, will...

Configuring the Inverter for Multiple Motors
Operations
and Monitoring
4–76
Configuring the Inverter for Multiple Motors
Simultaneous 
ConnectionsFor some applications, you  may need to connect two 
or more motors (wired in parallel) to a single 
inverter’s output. For example, this is common in 
conveyor applications where two separate conveyors 
need to have approximatel y the same speed. The use 
of two motors may be less expensive than making the 
mechanical link for one motor to drive multiple...

SJ7002 Inverter
Operations
and Monitoring
4–77
Parameters for the second motor and third motors  have function codes of the form x2xx and 
x3xx respectively. They appear immediately after the first motor’s parameter in the menu 
listing order. The following table lists the pa rameters that have the second/third parameter 
registers for programming.
Function Name
Parameter Codes
1st motor2nd motor3rd motor
Acceleration time setting (Acceleration 1) F002 F202 F302
Deceleration time setting (Deceleration 1)...

Configuring the Inverter for Multiple Motors
Operations
and Monitoring
4–78
Motor constant J setting (Standard, Auto 
tuning) H024/H034 H224/H234 —
PI proportional gain H050 H250 —
P proportional gain setting H052 H252 —
0Hz SLV limit for 1st motor H060 H260 —
Function Name
Parameter Codes
1st motor2nd motor3rd motor

Phone: 800.894.0412   

Inverter System 
Accessories
In This Chapter....page
— Introduction.......................................................................................   2
— Component Descriptions..................................................................   3
— Dynamic Braking....................................................... ........................  6
5

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