High Frequency Voltage Injection - Danfoss iC7 Motion Series Application Manual

Application Guide | iC7 Series Motion
Table 1: Motor Control Features and Motor Types (continued)
Motor type/Feature
Process functional- Mechanical brake
ity and protections control in closed
loop
Missing motor
phase
Motor thermal pro-
tection
Electronic thermal
relay (ETR)

High Frequency Voltage Injection

2.11.2
For salient pole synchronous motors under FVC+, High Frequency Voltage Injection (HFVI) is an encoder/resolver alternative for rotor
position detection at low speeds. If the motor has sufficient saliency (typically larger than 1.1), HFVI allows applications to run open loop
with performance like closed loop.
In a salient pole motor, the magnetic material of the rotor is not rotationally symmetric, as opposed to a non-salient pole motor where it
is. That means that the magnetic path through different diameters of the rotor varies. This variation results in different values of Lq and
Ld inductances, which can be used to determine the orientation of the rotor. The saliency ratio is the ratio between Lq and Ld.
Commissioning HFVI
A typical HFVI commissioning workflow is:
1.
Set 4.3.1.1 Motor Control Principle to FVC+.
2.
Enter the product label data to 4.2.4 Permanent Magnet Motor and set 4.2.1.1 Motor Type.
3.
Run full AMA: Set 4.2.1.4 Ama Mode to Motor Data and start the drive.
4.
Enable HVFI by setting 4.3.3.4 Low Speed Mode.
While HVFI is enabled, the saliency ratio is validated.
Table 2: Saliency ratios
Saliency ratio (Lq/Ld)
SR ≤ 1.1
1.1 < SR < 1.5
HFVI parameters
The setup parameters are all located under 4.3.3 FVC+ Settingsin the 4.3 Motor Control menu. HFVI is enabled by setting 4.3.3.4 Low
Speed Mode (1 in the following picture) to HF Injection.
© 2023.11
Induction motors
FVC+
X
X
X
X
Drive response
Motor start prevented.
Warning issued in the event log. Tracking capabilities are possibly reduced.
Synchronous motors
VVC+ FVC+
- X
X X
X X
X X
AB318753549016en-000301 / 136R0284 |
VVC+
-
X
X
X
21