Maxsine EP3 AC Series, Руководство пользователя

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Chapter 4 Running
82
T
i
：
The integral time-constant of speed loop;
K
p
： The gain of position loop;
G
：
The inertia ratio of load (P017);
J
L
：
The load inertia referred to the rotor shaft;
J
M
： The rotor inertia of the servomotor.
1. The gain of speed loop K
v
The speed loop gain Kv directly determines the response bandwidth of the speed loop. Under
the premise that there is no vibration in the mechanical system or noise, increases the speed loop
gain, then the speed response can speed up, and is better to follow the speed command. However,
it is easy to cause a mechanical resonance if the Kv is too large. The bandwidth of speed loop
expresses as:
) (
/ 1
1
) ( bandwidth loop Speed Hz K
J J
G
Hz
v
M L




If the setting inertia ratio of the load G is correct (G=JL/JM), then the bandwidth of the speed
loop is equal to the speed loop gain Kv.
2. The integral time-constant of speed loop T
i
The integral item of speed loop has an effect to eliminate static error of speed, and has rapid
reaction to a slight speed change. Under the premise that there is no vibration in the mechanical
system or noise, reduces the integral time constant Ti of speed loop, then the stiffness of the
system increases, and reduces the static error. If load inertia ratio is very big or a resonating factor
exists in the mechanical system, and then must confirm that the integral time constant is big
enough, otherwise the mechanical system will be easy to cause resonating. If the setting inertia
ratio of the load G is correct (G=JL/JM), uses following formula to obtain the integral time
constant Ti of the speed loop.
) ( 2
4000
) (
Hz K
ms T
V
i



3. The gain of position loop K
p
The gain of the position loop directly determines the reaction rate of the position loop. Under
the premise that there is no vibration in the mechanical system or noise, increases the position
loop gain, then speeds up the reaction rate, reduces the position tracking error and the positioning
time is shorter. However, it is easy to cause a mechanical vibration or over travel if the Kp is too
large. The bandwidth of the position loop should be lower than the bandwidth of speed loop. In
general:
4
Hz) ( bandwidth loop Speed
) ( bandwidth loop Position

Hz
If the setting inertia ratio of the load G is correct (G=JL/JM), uses the following formula to
obtain the gain Kp of the position loop: