gefran GRM-H 15 User Manual

819XX_MAN_GRM-H_11-2022_ENG_pag. 69
5.6.4. Feedback mode
The GRM-H offers the following possibilities to control
power through feedback:
•V voltage;
• V2 Quadratic voltage;
• I Current;
• I2 Quadratic current;
• P Power.
• Z Impedance
Enabling of the control mode is set via parameter hd.6
Voltage feedback (V)
This is used to maintain a constant load voltage. It
compensates possible variations in line voltage from
the rated voltage (value stored in the parameter riF.V,
expressed in Vrms).
The voltage value maintained on the load is equal to
the result of the formula
rif.V × (Ou.P [%] / 100)
and is contained in parameter Fb.r1.
Quadratic voltage feedback (V
2
)
This is used to maintain a constant load voltage. It
compensates possible variations in line voltage from
the rated voltage (value stored in the parameter riF.V,
expressed in Vrms).
The voltage value maintained on the load is equal to
the result of the formula
rif.V × sqrt(Ou.P [%] / 100)
and is contained in parameter Fb.r1.
Current feedback (I)
This is used to maintain a constant load current. It
compensates possible variations in line voltage and/
or load impedance with respect to the rated current
(value stored in the riF.I parameter, expressed in
Arms).
The current value maintained on the load is equal to
the result of the formula
rif.A × (Ou.P [%] / 100)
and is contained in parameter Fb.r1.
Quadratic current feedback (I
2
)
This is used to maintain a constant load current. It
compensates possible variations in line voltage and/
or load impedance with respect to the rated current
(value stored in the riF.I parameter, expressed in
Arms).
The current value maintained on the load is equal to
the result of the formula
rif.A × sqrt(Ou.P [%] / 100)
and is contained in parameter Fb.r1.
Power feedback (P)
This is used to keep the load power constant. It
compensates possible variations in line voltage and/
or load impedance with respect to the rated power
(value stored in riF.P, expressed in kWatts).
The power value maintained on the load is equal to
the result of the formula
rif.P × (Ou.P [%] / 100)
and is contained in parameter Fb.r2.
Impedance Feedback (Z)
This is used to keep the load impedance constant. It
compensates possible variations in line impedance
with respect to the rated impedance (value stored in
riF.P, expressed in ohm).
The impedance value maintained on the load is equal
to the result of the formula
rif.I × (Ou.P [%] / 100)
and is contained in parameter Fb.r2.
IMPORTANT!
Feedback calibration can be activated by digital input
or by serial command (Modbus bit 15) or IO-Link.
If required, calibration MUST only be activated after
first setting parameter hd.6 = 0 and preferably under
conditions of maximum power on the load (e.g., Ou.P
[%] at 100%).
Only after calibration has been carried out can the
parameter hd.6 be set to the desired value.
If the operating mode is changed (PA, ZC, BF, HSC),
the feedback calibration procedure outlined above
must be repeated.
For non-linear loads (e.g. Super Kanthal or Silicon
Carbide type) the automatic calibration procedure IS
NOT NEEDED
but the value of parameters riF.V, riF.I, riF.P must be
set directly based on the rated specification of the
load shown in the data sheet

gefran GRM-H 15 Specifications

General

Brand	gefran
Model	GRM-H 15
Category	Controller
Language	English