Kikusui PLZ-4W Series, Руководство пользователя

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A-4 Appendix PLZ-4W
A.2.2 Operation of the CR Mode
In CR mode, the PLZ-4W sinks current proportional to the voltage variation.
■
CR mode operation
When the PLZ-4W is used in CR mode, the PLZ-4W operates as a resistive load as
shown in Fig. A-4. When the voltage (V1) of the constant-voltage power supply var-
ies, the PLZ-4W sinks current to maintain I = V/R, with the speci
fi ed resistance R
fi xed. This mode cannot be used with an AC circuit.
Fig. A-4 Equivalent circuit of the constant resistance load and opera-
tion
■
Transition of the operating point: Overpower protection (OPP)
We will consider the case when checking the load characteristics of the constant-
voltage power supply of Fig. A-4 using CR mode.
Fig. A-5 Transition of the operating point in CR mode (OPP trip point)
If the overcurrent protection (OCP) setting I
OCP
is greater than the current value I
B
at point B, when the PLZ-4W resistance is decreased (R
1
→
R
2
→
R
B
) and the input
current (load current) is increased with the voltage of the constant-voltage power
supply at V1, the operating point moves along segment AB (A
1
→
A
2
→
B). When
point B is reached, overpower protection (OPP) trips.
At this point, two types of operation are available on the PLZ-4W depending on the
protection action setting of the OPP.
If Protect Action is set to LOAD OFF, the load is turned off.
0
V
2
V
1
I
1
I
2
V
2
V
1
I
1
I
2
= =
R
I
V
PLZ-4W Series Electronic Load
Constant voltage
power supply
Resistance (V/I) is constant
even when the voltage and
current vary
Current I
Voltage V
V1
Input current [A]
Input
voltage [V]
Log scale
V1
A
B
Constant power line
(OPP setting)
Operating area
OPP trip point
Constant resistance line
(Constant resistance settings: R
1
, R
2
, and R
B
)
I
B
I
OCP
A
1
A
2
R
1
R
2
R
B