Patent ID: 11955908
Assignee: APPLE INC.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  G | IPC H

Claim 16:
17. An energy storage system comprising:
a battery;
a power converter comprising a first plurality of switching devices coupled to the battery and a second plurality of switching devices coupled between the first plurality of switching devices and an AC power system; and
control circuitry that determines whether the AC power system is a single/split phase system or a three phase system and operates the first and second pluralities of switching devices accordingly;
wherein the control circuitry comprises a microcontroller and a plurality of voltage sensors each configured to monitor a magnitude and a phase of a voltage to allow the control circuitry to determine whether the AC power system is a single/split phase system or a three phase system and whether the AC power system is connected with a line to line or line to neutral fault condition; and
wherein the first plurality of switching devices comprises three legs, each leg having a first switch coupled between a first input terminal couplable to the energy storage device and a high rail of an intermediate DC bus and a second switch coupled between the first input terminal and a low rail of the intermediate DC bus, and
if the control circuitry determines that the connected AC power system is a single/split phase system, the control circuitry provides drive signals to the first plurality of switching devices to operate all three legs in an interleaved manner to generate a DC bus voltage of the intermediate DC bus; and
if the control circuitry determines that the connected AC power system is a three phase system, the control circuitry provides drive signals to the first plurality of switching devices to operate two legs in an interleaved manner to generate the DC bus voltage of the intermediate DC bus; and

the second plurality of switching devices comprises three legs, each leg having a first switch coupled between a high rail of the intermediate DC bus and an output terminal couplable to the AC power system and a second switch coupled between a low rail of the intermediate DC bus and an output terminal couplable to the AC power system, and
if the control circuitry determines that the connected AC power system is a single/split phase system, the control circuitry provides drive signals to the second plurality of switching devices to operate a first leg to generate a first AC voltage, a second leg to generate a second AC voltage 180 degrees out of phase with respect to the first AC voltage, and a third leg to balance the first and second voltages; and

if the control circuitry determines that the connected AC power system is a three phase system, the control circuitry provides drive signals to the first plurality of switching devices to operate each leg to generate an AC voltage that is 120 degrees out of phase with respect to the AC voltage generated by the other two legs.