CPC H02J 9/061 (2013.01) [H02M 3/04 (2013.01)] | 20 Claims |
1. A power supply system comprising:
an uninterruptible power supply (UPS) comprising an input coupled to an AC source and configured to receive input AC power from the AC source and an output configured to provide AC output power to a load, the UPS including a converter coupled to the input, an inverter coupled to the output, and a DC bus coupled between the converter and the inverter;
a renewable power source configured to provide DC power derived from a renewable energy source;
an energy storage device;
a first DC/DC converter coupled between the renewable power source and the DC bus and configured to provide DC power derived from the renewable power source to the DC bus;
a second DC/DC converter coupled between the DC bus and the energy storage device; and
a controller in communication with the first DC/DC converter and configured to monitor an output power capability of the renewable power source, operate the first DC/DC converter to provide the DC power derived from the renewable power source to the DC bus based on the output power capability of the renewable power source; determine that the energy storage device is at least partially uncharged, and in response to determining that the energy storage device is at least partially uncharged, operate the second DC/DC converter to provide a variable charging current to the energy storage device, a magnitude of the variable charging current set by the controller to a first non-zero value as a function of load demand at the output being at a first level and the magnitude of the variable charging current set by the controller to a second non-zero value as a function of the load demand being at a second level.
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