Emerson Epsilon EP Drive 400518-01 Instrukcja Instalacji Pobierz pdf (Strona 195)

183

Tuning Procedures

load disturbance corrections but will affect their cycle frequency. The response level generally should be decreased as the

load to motor inertia ratio increases or if High Performance Gains are enabled.

Feedforwards

Feedforward gains are essentially open loop gains that generate torque commands based on the commanded velocity, accel/

decel and the known load parameters (Inertia Ratio and Friction). Using the feedforwards reduces velocity error during steady

state and reduces overshoot during ramping. This is because the Feedforwards do not wait for error to build up to generate

current commands.

Feedforwards should be disabled unless the absolute maximum performance is required from the system. Using them reduces

the forgiveness of the servo loop and can create instability if the actual inertia and/or friction of the machine varies greatly

during operation or if the Inertia Ratio or Friction parameters are not correct.

The internal feedforward velocity and acceleration gains are calculated by using the Inertia Ratio and Friction parameters.

The feedforward acceleration gain is calculated from the Inertia Ratio parameter and the feedforward velocity gain is

calculated from the Friction parameter.

When Feedforwards are enabled, the accuracy of the Inertia Ratio and Friction parameters is very important. If the Inertia

Ratio parameter is larger than the actual inertia, the result would be a significant velocity overshoot during ramping. If the

Inertia parameter is smaller than the actual inertia, velocity error during ramping will be reduced but not eliminated. If the

Friction parameter is greater than the actual friction, it may result in velocity error or instability. If the Friction parameter is

less than the actual friction, velocity error will be reduced, but not eliminated.

Feedforwards can be enabled in any operating mode, however, there are certain modes in which they do not function. These

modes are described in the table below.

Low Pass Filter Group

The Low Pass Filter will reduce machine resonance due to mechanical coupling and other flexible drive/load components by

filtering the command generated by the velocity loop. A check box on the Tuning view enables a low pass filter applied to

the output of the velocity command before the torque compensator. The low pass filter frequency parameter defines the low

pass filter cut-off frequency. Signals exceeding this frequency will be filtered at a rate of 40 dB per decade. The default value

is 600Hz.

Line Voltage (EN Only)

Line Voltage specifies the applied power and adjusts the internal gains to compensate for it. This parameter has two choices

115 VAC and 230 VAC. If the Line Voltage is set to 230 VAC when the actual applied voltage is 115 VAC, the motor will

be slightly less responsive to commands and load disturbances.

The Line Voltage must never be set to 115 VAC if the applied voltage is actually 230 VAC. This can cause drive

instability and failure, resulting in property damage.

Determining Tuning Parameter Values

For optimum performance you will need to enter the actual system parameters into the drive. This section discusses the

methods which will most accurately determine those parameters.

Note

If you have an application which exerts a constant unidirectional loading throughout the travel such as in a vertical axis,

the inertia tests must be performed in both directions to cancel out the unidirectional loading effect.

Operating Mode Feedforward Parameters Active

Accel FF Vel FF

Analog Velocity No Yes

Preset Velocity Yes Yes

Pulse/Position No No

Summation No Yes

1 2 ... 190 191 192 193 194 195 196 197 198 199 200 ... 239 240

Emerson Epsilon EP Drive 400518-01 Instrukcja Instalacji Strona 195

Komentarze do niniejszej Instrukcji

Emerson Epsilon EP Drive 400518-01 Instrukcja Instalacji Strona 195

Komentarze do niniejszej Instrukcji

Powiązane produkty i podręczniki dla Oprogramowanie Emerson Epsilon EP Drive 400518-01