PV-45208 Photovoltaic Inverter
Operation and Maintenance Manual
Copyright 2002, Xantrex Technology Inc.
DOCUMENT: 151710
4-4
SECTION 4
OPERATION
Current Imbalance Detection
In the event of phase-to-phase current imbalance of greater than 20% between phases, the inverter will
execute an orderly shutdown, and annunciate a fault at the operator interface. See Section 5, Trouble-
shooting, for further information on this fault condition.
DC Overvoltage Detection
In the event of DC voltage greater than 600Vdc, the PV-45208 will execute an orderly shutdown and
annunciate a fault to the operator interface. If DC voltage remains greater than 600Vdc, the PV-45208
may be irreparably damaged. See Section 5, troubleshooting for further information on this fault condi-
tion.
Peak Power Tracking
The PV-45208 control software employs an active PV peak power tracker, designed to maintain maxi-
mum power output from the PV array at all times of operation. The peak power voltage point varies
primarily depending upon the temperature of the PV cells. The PV-45208 constantly seeks the opti-
mum voltage and current operating points of the PV array to maintain maximum PV power output.
Automatic Wake Up PV Voltage Optimization
Every day the PV-45208 wakes up and starts producing power, the control software determines if it is
necessary to make adjustments to the start voltage setpoint. If the PV-45208 wakes up and determines
that there is insufficient PV array power to support inverter operation, the start voltage setpoint is
shifted slightly higher. This assumes that once the voltage on the array has risen, there will be greater
PV power as the PV array is exposed to higher irradiance. Conversely, if the PV-45208 wakes up and
determines that there is more power than is necessary to support inverter operation, the PV start voltage
setpoint is lowered. The PV start voltage setpoint will usually be optimized over the period of one
week. This value may be manually adjusted via the graphical user interface program to expedite the
optimization process. There is also a user settable timer that determines the time required for the PV
start voltage to exceed the start voltage setpoint. This timer may also be manually adjusted via the
graphical user interface to help compensate for poorly placed PV arrays. The default wake-up time
delay is factory set at five minutes.
Automatic Sleep Test
Toward the end of every solar day, the PV-45208 automatically determines when to stop producing
power dependent upon the output power of the inverter. As the net output power of the PV-45208 nears
zero, a timer is started to allow the inverter to ride through any brief irradiance reductions. The default
sleep time delay is factory set at five minutes.
