Wesley BC-620-4CA User Manual

Page 33

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Curtis 1234/36/38 Manual,

OS

11

29

2 3 J U LY 2 0 0 8 D R A F T

3 — PROGRAMMABLE PARAMETERS:

Speed Controller & Velocity Feedforward Parameters

(SPEED MODE)

1 – SPEED MODE

SPEED CONTROLLER MENU

ALLOWABLE

PARAMETER

RANGE

DESCRIPTION

Max Speed

100–8000 rpm

Defines the maximum requested motor rpm at full throttle. Partially-applied

Max_Speed_SpdM

100–8000

throttle is scaled proportionately; e.g., 40% applied throttle corresponds to
a request for 40% of the set Max Speed Value.

If Max_Speed_SpdM is set <100 rpm (through VCL or CAN), the throttle

request is zeroed.

Note: The maximum motor rpm is subject to the constraints on page 27.

Kp

0–100 %

Determines how aggressively the speed controller attempts to match

Kp_SpdM

0–8192

the speed of the motor to the commanded speed. Larger values provide
tighter control.

If the gain is set too high, you may experience oscillations as the

controller tries to control speed. If it is set too low, the motor may behave
sluggishly and be difficult to control.

Ki

5–100 %

The integral term (Ki) forces zero steady state error, so the motor will run

Ki_SpdM

50–1000

at exactly the commanded speed. Larger values provide tighter control.

If the gain is set too high, you may experience oscillations as the

controller tries to control speed. If it is set too low, the motor may take
a long time to approach the exact commanded speed.

1 – SPEED MODE

VELOCITY FEEDFORWARD MENU

[OPTIONAL]

ALLOWABLE

PARAMETER

RANGE

DESCRIPTION

Kvff

0–500 A

This velocity feedforward term is designed to improve throttle responsiveness

Kvff_SpdM

0–5000

and speed controller performance, especially at low speeds.

For traction systems, set it to 50–70% of the current needed to maintain

a very low speed, unloaded, on flat ground.

For a pump system, set it to the lowest load current (i.e., the current

running at the minimum load). Alternatively, the responsiveness of a pump
speed control loop can be significantly enhanced by using a VCL program to
continuously update this parameter to the appropriate value as each pump
load is requested.

Build Rate

0.1–5.0 sec

Determines how fast the Kvff term builds up.

Vel_FF_Build_Rate_SpdM

100–5000

For traction systems, if you feel or hear the mechanical slop pick up

abruptly when you move the throttle from neutral to a very small value,
slowing the build rate (i.e., setting it to a higher value) will soften the feel.

For a pump system, start with this parameter at the minimum setting.

Slowing it down (i.e., setting it to a higher value) will reduce speed overshoot
if too much feedforward has been commanded.

Release Rate

0.1–2.0 sec

Determines how fast the Kvff term releases. If the release seems too abrupt,

Vel_FF_Release_Rate_SpdM

100–2000

slowing the release rate (i.e., setting it to a higher value) will soften the feel.

It should be set fast enough (i.e., at a low enough value) to prevent the

vehicle from running on after throttle release.

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