Slip Compensation; Dc Braking Enable - Reliance electric GV3000/SE Instruction Manual

H.004

Slip Compensation

Parameter Range: 0.0% - 10.0% of Motor Nameplate Base Frequency (H.001)
Initial Setting: 0.0% (no slip compensation)
Type: Tuneable (at rest or during operation)
Refer to: P.095 Power Unit Output Amps
Description: This parameter is used to improve motor speed regulation by increasing the output
frequency applied to the motor (the percentage of frequency rise at Power Unit
Output Amps (P.095)).
The level of increased output frequency is a function of the value entered in H.004 (Motor
Nameplate Amps) and actual motor current.
Actual motor shaft speed is determined by two factors: inverter output frequency and the slip of the
motor. The speed reference is converted into output frequency. Motor slip is determined by the
type of induction motor and varies with load.
If the parameter is set to zero, motor speed will not be proportional to speed reference, but will
vary depending on load.
'Slip compensation' measures inverter output current and (at rated load) increases the output
frequency by the percentage entered in H.004. Below rated load, slip compensation will increase
inverter output frequency by the percentage in H.004 multiplied by the percent of rated load.
At load changes, the long-term speed behavior of the motor is greatly improved through the use of
this parameter.
To calculate the value entered for H.004, use the following equation:
100 * (Synch. RPM -Nameplate RPM)
H.004 = ---------------------------------------------
Synchronous RPM = 120 * Frequency / number of Motor Poles
Example : V/Hz mode, 2kHz, 2 motors paralleled, 1435 RPM,
Sum of 2 motor currents = 50% Power Unit Output Amps (P.095)
H.004 =100 *( 1500-1435) * 100% = 8.67%
H.005

DC Braking enable

Parameter Range: OFF – Disable DC Braking
ON
Initial Setting: OFF
Type: Tuneable (at rest or during operation)
Refer to: P.025 Stop Mode
H.007 DC Braking Current
H.017 Input Power/Snubber Configuration
Description: This parameter enables or disables DC Braking.
DC Braking is used to provide additional motor braking (by DC current flow through
motor windings) at speeds below Braking Start Frequency (H.006).
If DC Braking is required, DC Braking functions (H.008, H.007) must be >zero (0).
When the motor decelerates to the pre-set DC Braking Start Frequency (H.006), the
DC Braking Current (H.007) is applied to the motor after a power module-
dependent delay time. However, if parameter H.017 is set to 1 or 5, then there is no
delay for DC Braking Time (H.008).
NOTE: This function will not provide holding torque as a mechanical brake. D-C-braking is
only operative when Stop Mode Selection (P.025) is set to 1 (Ramp to rest stop).
49'1329 e
5 - V/HZ REGULATION MODE
Synchronous RPM
1500
– Enable DC Braking
H.001 Motor Nameplate Base Frequency
Power Unit Output Amps (P.095)
* --------------------------------------------
(Total) Motor(s) Nominal Current
50%
H.006 DC Braking Start Frequency
H.008 DC Braking Time
GV3000/SE 5 - 5