Lenze i700 - Manual (Page 95)

Lenze · i700 servo inverter · Reference manual · DMS 1.5 EN · 03/2014 · TD05
95
5 Motor control & motor settings
5.10 Synchronous motor (SM): Pole position identification
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5.10 Synchronous motor (SM): Pole position identification
For the control of a permanent-magnet synchronous motor, the pole position – the angle between
motor phase U and the field axis of the rotor – must be known.
• For Lenze motors with an absolute value encoder or resolver, the pole position is already set
correctly.
• When incremental encoders (TTL or sin/cos encoders without absolute position information)
are used, a pole position identification (PPI) is always required after switching on the mains
(initialisation), even with Lenze motors.
Functions for pole position identification
For the identification of the pole position of the currently activated motor encoder, the following
three functions are available:
• Pole position identification PPI (360°)
• Pole position identification PPI (min. movement)
• Pole position identification PPI (without movement)
The functions should yield similar results. Due to e.g. friction, bearing forces, and a trapezoidal field
profile, the results may deviate. Here, the function that includes one full revolution (360°) will
provide the most precise results and the function without any motion will provide the most
inaccurate results. An increase in the percentage of the current amplitude helps provide more
precise results.
You can find detailed information on the respective function in the following subchapters.

Note!
Only required:
• For servo control with synchronous motor of a third-party manufacturer.
• For servo control with synchronous motor and use of incremental encoders (TTL or
sin/cos encoders as well as resolvers).
• After changes of the motor feedback system, e.g. encoder exchange.

Danger!
In case of firmly braked motors (e.g. for hanging loads), only the "pole position
identification PLI (without motion)" function may be used!
For the other two functions "Pole position identification PLI (360°)" and "Pole position
identification PLI (min. motion)" the motor must not be braked or blocked during the
pole position identification!