Morningstar TriStar TS-MPPT-30, Инструкция по установке и эксплуатации

Страница: 30 / 68

30 Operation
Operation 4.0
The TriStar MPPT operation is fully automatic. After installation is completed, there are few op-
erator tasks to perform. However, the operator should be familiar with the operation and care of
the TriStar MPPT as described in this section.
4.1 TrakStar
TM
MPPT Technology
The TriStar MPPT utilizes Morningstar’s TrakStar
TM
Maximum Power Point Tracking technology
to extract maximum power from the solar array. The tracking algorithm is fully automatic and
does not require user adjustment. TrakStar
TM
technology tracks the array
maximum power point
as it varies with weather conditions, ensuring that maximum power is harvested from the array
through the course of the day.
Current Boost
Under most conditions, TrakStar
TM
MPPT technology will “boost” the solar charge current. For
example, a system may have 36 Amps of solar current fl owing into the TS-MPPT and 44 Amps
of charge current fl owing out to the battery. The TriStar MPPT does not create current! Rest as-
sured that the power into the TriStar MPPT is the same as the power out of the TriStar MPPT.
Since power is the product of voltage and current (Volts x Amps), the following is true*:
(1) Power Into the TriStar MPPT = Power Out of the TriStar MPPT
(2) Volts In x Amps In = Volts Out x Amps Out
* assuming 100% efficiency. Losses in wiring and conversion exist.
If the solar module’s
maximum power voltage
(V
mp
) is greater than the battery voltage, it follows
that the battery current must be proportionally greater than the solar input current so that input
and output power are balanced. The greater the difference between the V
mp
and battery voltage,
the greater the current boost. Current boost can be substantial in systems where the solar array
is of a higher nominal voltage than the battery as described in the next section.
High Voltage Strings and Grid-tie Modules
Another bene fi t of TrakStar TM MPPT technology is the ability to charge batteries with solar arrays
of higher nominal voltages. For example, a 12 Volt battery bank may be charged with a 12-, 24-,
36-, or 48-Volt nominal off-grid solar array. Grid-tie solar modules may also be used as long as
the solar array
open circuit voltage
(V
oc
) rating will not exceed the TriStar MPPT 150 Volt maxi-
mum input voltage rating at worst-case (coldest) module temperature. The solar module docu-
mentation should provide V
oc
vs. temperature data.
Higher solar input voltage results in lower solar input current for a given input power. High voltage
solar input strings allow for smaller gauge solar wiring. This is especially helpful and economical
for systems with long wiring runs between the controller and the solar array.