Maximum Switching Frequency; High Stability Space Vector Modulation - Emerson Unidrive M200 Parameter Reference Manual

The steady state parameters are converted to equivalent transient model parameters:
R = R
s 1
L = L
m m
L = L + L
s 1 m
L = L + L
r 2 m
2
σL = L - (L / L )
s s m r
The equivalent drive parameters are:
Stator Resistance (05.017) = R
Transient Inductance (05.024) = σLs
Stator Inductance (05.025) = L
Parameter

05.018 Maximum Switching Frequency

Short description Defines the maximum switching frequency that can be used by the drive
Mode Open‑loop
Minimum 0
Default 3
Type 8 Bit User Save
Display Format Standard
Coding RW, TE, VM, RA
Value Text
0 0.667
1 1
2 2
3 3
4 4
5 6
6 8
7 12
8 16
Maximum Switching Frequency (05.018) should be set to the required PWM switching frequency. The drive inverter will operate at this frequency unless Auto-
switching Frequency Change Disable (05.035) = 0 and the inverter temperature exceeds the threshold for automatic switching frequency reduction (see
Inverter Temperature (07.034)). The actual switching frequency is shown in Switching Frequency (05.037). The switching frequency has a direct effect on the
sample rate for the current controllers (see Current Controller Kp Gain (04.013)). All other control tasks are at a fixed rate of 1ms.
As default Auto-switching Frequency Change Disable (05.035) = 0 and the system described above is always active. If Auto-
switching Frequency Change Disable (05.035) = 1 then the automatic switching frequency changing system is disabled.
We recommend that a minimum ratio of 12:1 for the switching frequency compared to the maximum output frequency is used.
Parameter

05.019 High Stability Space Vector Modulation

Short description Set to 1 to enable High Stability Space Vector Modulation
Mode Open‑loop
Minimum 0
Default 0
Type 1 Bit User Save
Display Format Standard
Coding RW
Unidrive M200 Parameter Reference Guide
Issue: 01.05.00.10
s
s
Maximum VM_MAX_SWITCHING_FREQUENCY
Units kHz
Update Rate Background read
Decimal Places 0
Description
667Hz switching frequency
1kHz switching frequency
2kHz switching frequency
3kHz switching frequency
4kHz switching frequency
6kHz switching frequency
8kHz switching frequency
12kHz switching frequency
16kHz switching frequency
Maximum 1
Units
Update Rate Background read
Decimal Places 0
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