Atec Chroma-63800 Series - Manual (Page 2)

Complete AC & DC Load Simulations
Chroma's 63800 AC/DC Electronic Load is designed for both AC & DC Load Simulations. Illustrated below are the various load modes
which are available:
AC Load Simulation
AC Load Simulation DC Load Simulation
Constant Load Modes
CC Mode
CR Mode
CP Mode
Rectified Load Modes
CR Mode
CV Mode
CP Mode
CC Mode
Rectified Mode
RLC Mode
CP Mode
Inrush Mode
Constant Load Modes
The Constant Load Modes allow users to set the following operating
modes : CC, CR and CP mode. The CC & CP modes in this category
allow users to program PF or CF, or both. For CR mode the PF is
always set to 1.
When both the PF & CF of the loading current are programmed,
the 63800 load controls power factor from 1 to 0 by shifting the
current (with CF defined) relative to the input voltage to get desired
displacement power factor. The power factor range will be limited
based on crest factor programmed. If the programmed PF is positive
then the current will lead the voltage waveform, in opposite, when PF
is set negative, the current will then leg the voltage waveform. (See
below)
The Model 63800 AC/DC Electronic Load provides two unique operating modes for AC load simulation; (1) Constant Load Modes and
(2) Rectified AC Load Modes. Each are described below.
As seen in Figure 1, for a crest factor of 1.414, the programmed power factor can only be 1 if the input voltage is sine-wave. However, for a CF
of 2.0, the acceptable PF ranges from 0.608 to 0.85; for CF = 3, the PF can then be set from 0.211 to 0.6, etc. So, higher crest factors enable
wider range of power factors.
Figure 1: Crest Factor vs. Power Factor control Range
CF
I
= I peak / I rms
PF = True power / Apparent power
PF
CFI
Model 63800