24VDC Power Hub 3500 Operator Manual
January 2020
|
Solar Stik
®
, Inc.
12
|
THEORY OF OPERATION
Operation Overview
The Power Hub has multiple DC connections on its exterior, allowing for multiple configuration
possibilities.
It requires connection to an active 24 V battery circuit in order for it to operate. A minimum of three
(3) energy storage modules (i.e., Expander Paks) must be present and functioning for the Power
Hub to be able to operate at its rated power, however, for lower power configurations, a single
energy storage module (ESM) or small bank of ESMs may be used.
The Hub has an internal DC bus that can support multiple
regulated
DC generation sources to
include the following:
• Wind
• Fuel Cell
• Vehicular
• Hydro
It also has a dedicated circuit for managing
unregulated
power from PV arrays. The Hub has a
sophisticated ultra-fast Maximum Power Point Tracking (MPPT) PV charge controller system that
regulates PV power, and optimizes PV power production based on two factors:
1. Available PV power
2. Battery State-of-Charge (SoC)
The MPPT process allows a PV array to operate at its rated/available voltage, turning the higher
PV voltage into charging current (amps), which is then provided to the battery at the appropriate
voltage, improving performance and life of the batteries.
Battery Charging and Recovery
The solar charger controllers can be programmed to charge using several algorithms, including
multi-stage charging for lead-acid batteries as well as Constant Current / Constant Voltage (CC/
CV) for lithium battery types. Selection of charge algorithms should be based on battery chemistry,
capacity and operating conditions.
The Power Hub can also be used to resuscitate over-discharged batteries. Incoming PV power will
activate the PV controls and begin the charging process, even if the battery voltage has dropped to
levels that cause other components (PRO-Verters, Power Distribution Modules, etc) in a system to
shut down due to low voltage.
Protection Circuits
The Power Hub serves as a DC junction within the Inter-Connect Circuit .
When connected to
an active 24V DC Inter-Connect network, it allows DC to flow through its internal bus, with ONLY the
PV circuit offering limit protections: