Kikusui PLZ-4W Series, User Manual

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PLZ-4W Basic Operation 5-29
5.15 Response Speed
The PLZ-4W operates by detecting the input current or voltage and feeding back
those values. You can set the response speed of the negative feedback control. The
response speed can be speci
fi ed in CC mode (CC+CV mode) and CR mode
(CR+CV mode). You can decrease the response speed to assure stable operation.
If the load wire is long or has a large loop, the wire inductance is increased. Conse-
quently, the current variation at the time of switching operation will cause a large
voltage drop.
In such condition, the input voltage may fall below the minimum operating voltage
of the PLZ-4W causing the current waveform to be distorted. In some cases, the
input voltage may exceed the maximum input voltage and cause damage to the
PLZ-4W. You must be careful especially when the slew rate setting is high or
switching is performed using large currents through parallel operation.
In such case, it is important that you use the shortest twisted wire possible for the
connection. Then, decrease the slew rate setting or lower the response speed so that
the voltage induced by the inductance is within the minimum operating voltage and
the maximum input voltage range of the PLZ-4W.
In the case of DC operation also, the phase lag of the current may cause instability
in the PLZ-4W control inducing oscillation. In this case also, use the shortest
twisted wire possible for the connection, and achieve stable operation by lowering
the response speed.
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Response speed type and performance
The following four levels are available. Select one of the levels.
1/1: Normal response speed
1/2: 1/2 the normal response speed (Slows down by a factor of 2.)
1/5: 1/5 the normal response speed (Slows down by a factor of 5.)
1/10:1/10 the normal response speed (Slows down by a factor of 10.)
The default setting is 1/1.
Settings other than 1/1 slow down the speed and affect the performance of soft start
and slew rate as well as the rise and fall times of load on/off.
The slew rate in turn affects the switching operation.
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Setting the response speed
You can set the response speed of the PLZ-4W using “1. Setup” | “2. Response”
from the menu.
For a description of changing the menu setup, see section 5.13, “Menu Setup.”
When using parallel operation or high speed load simulations (such as switching
function), refer to the “Technical Note for the electronic load (PLZ-4W), When
operating under parallel operation or high-speed load simulations” as provided as
separate sheet and set the response speed properly.