Braking Igbt Upper Threshold; Low Voltage Braking Igbt Threshold; Low Voltage Braking Igbt Threshold Select; Low Dc Link Operation - Emerson Unidrive M200 Parameter Reference Manual

Voltage Default Value
110V 390
200V 390
400V 780
575V 930
690V 1120
Braking IGBT Lower Threshold (06.073) defines the lowest level of D.c. Link Voltage (05.005) where the braking IGBT will become active and Braking IGBT Upper Threshold (06.074) defines
the level of D.c. Link Voltage (05.005) where the braking IGBT will be on continuously. When the braking IGBT is turned on it will remain on for at least 1ms. The braking IGBT on-time is defined
by the thresholds and the d.c. link voltage as given in the table below where L = Braking IGBT Lower Threshold (06.073) and U = Braking IGBT Upper Threshold (06.074).
D.c. link voltage level
D.c. Link Voltage (05.005) < L
L ≤ D.c. Link Voltage (05.005) ≤ U
D.c. Link Voltage (05.005) ≥ U
As the D.c. Link Voltage (05.005) rises above the lower threshold the braking IGBT is active with an on/off ratio of 1/100. As the voltage rises further, the on/off ratio increases until at the upper
threshold the braking IGBT is on continuously. The upper and lower voltage threshold can be set up so that braking resistors in drives with parallel connected d.c. links will share the braking
load.
If Braking IGBT Lower Threshold (06.073) ≥ Braking IGBT Upper Threshold (06.074) then the braking IGBT is off when D.c. Link Voltage (05.005) Braking IGBT Upper Threshold (06.074) and
on if D.c. Link Voltage (05.005) ≥ Braking IGBT Upper Threshold (06.074). This method of control is the same as that used in Commander SK and the default values for the braking thresholds
are equal to the braking thresholds in Commander SK.
Unless sharing between braking resistors is required the braking thresholds do not normally need to be adjusted. Care should be taken when reducing the thresholds because if either threshold
is below the maximum value of the peak rectified supply voltage the braking resistor could take power from the supply.
The list below gives conditions that will disable the braking IGBT:
1. Braking IGBT Upper Threshold (06.074) = 0, or Low Voltage Braking IGBT Threshold Select (06.076) = 1 and Low Voltage Braking IGBT Threshold (06.075) = 0.
2. The drive is in the under-voltage state.
3. A priority 1, 2 or 3 trip is active.
4. There is a fault in the control system power supply.
5. The hardware or software over-temperature systems indicate that the braking resistor is too hot.
6. A braking IGBT over-current trip is active OI Brake.
Parameter

06.074 Braking IGBT Upper Threshold

Short description Defines the level of the d.c. bus voltage where the braking IGBT will be on continuously
Mode Open‑loop
Minimum −VM_DC_VOLTAGE_SET
Default See exceptions below
Type 16 Bit User Save
Display Format Standard
Coding RW, VM, RA
Voltage Default Value
110V 390
200V 390
400V 780
575V 930
690V 1120
See Braking IGBT Lower Threshold (06.073).
Parameter

06.075 Low Voltage Braking IGBT Threshold

Short description Defines the threshold used for low voltage braking
Mode Open‑loop
Minimum −VM_DC_VOLTAGE_SET
Default 0
Type 16 Bit User Save
Display Format Standard
Coding RW, VM, RA
If Low Voltage Braking IGBT Threshold Select (06.076) = 0 the normal thresholds are used. If Low Voltage Braking IGBT Threshold Select (06.076) = 1 then
Low Voltage Braking IGBT Threshold (06.075) is used for both upper and lower thresholds. This allows a different braking threshold to be set for low voltage operation.
Parameter

06.076 Low Voltage Braking IGBT Threshold Select

Short description Set to 1 enable low voltage IGBT braking
Mode Open‑loop
Minimum 0
Default 0
Type 1 Bit Volatile
Display Format Standard
Coding RW
See Low Voltage Braking IGBT Threshold (06.075)
Parameter

06.077 Low DC Link Operation

Short description Set to 1 to allow a 400V drive to be ran from a 240V supply
Mode Open‑loop
Minimum 0
Default 0
Type 1 Bit User Save
Display Format Standard
Coding RW
On the 400V product setting this bit will enable the drive to run from a 240VAC input. Low DC Link Operation is enabled when Low DC Link Operation (06.077) is set to one. See figure below.
Unidrive M200 Parameter Reference Guide
Issue: 01.05.00.10
On-time
0%
[(D.c. Link Voltage (05.005) - L) / (U - L)] x 100%
100%
Maximum VM_DC_VOLTAGE_SET
Units V
Update Rate Background
Decimal Places 0
Maximum VM_DC_VOLTAGE_SET
Units V
Update Rate Background
Decimal Places 0
Maximum 1
Units
Update Rate Background
Decimal Places 0
Maximum 1
Units
Update Rate Background read
Decimal Places 0
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