Ac switch pfc with integrated charger and dc-dc for online ups systems

An uninterruptible power supply (UPS) comprising:

• an input configured to receive input AC power having an input AC voltage;
• a backup power input configured to be coupled to a backup power source and to provide DC power to the backup power source for charging;
• a positive DC bus and a negative DC bus, the positive and negative DC busses being galvanically coupled to the backup power input;
• and
• a converter coupled to the input, the backup power input, and the positive and negative DC busses, the converter including
• a first inductor,
• a second inductor,
• a first converter switch configured to couple the first inductor to a neutral connection, wherein the first converter switch is a bidirectional switch circuit including a first switch and a second switch coupled in series,
• a second converter switch configured to couple the second inductor to the positive DC bus, and
• a third converter switch configured to couple the second inductor to the negative DC bus.

A method of operating an uninterruptible power supply (UPS) having an input configured to receive input AC power having an input AC voltage, a backup power input configured to be coupled to a backup power source and to receive backup DC power from the backup power source and provide DC power to the backup power source for charging, a positive DC bus and a negative DC bus, the positive and negative DC busses being galvanically coupled to the backup power input, and a converter coupled to the input, the backup power input, and the positive and negative DC busses, the converter including a first inductor, a second inductor, a first converter switch configured to couple the first inductor to a neutral connection, a second converter switch configured to couple the second inductor to the positive DC bus, a third converter switch configured to couple the second inductor to the negative DC bus, and a fourth converter switch configured to couple the second inductor to the backup power input, the method comprising:

• controlling the UPS to operate in a backup mode of operation responsive to determining that the acceptable AC power is not available at the input;
• operating, in the backup mode of operation, the first converter switch to provide DC power derived from the backup DC power to the positive DC bus via the first inductor;
• and
• operating, in the backup mode of operation, the fourth converter switch to provide DC power derived from the backup DC power to the negative DC bus via the second inductor.

At least one non-transitory computer-readable medium storing thereon sequences of computer-executable instructions for operating an uninterruptible power supply (UPS) having an input configured to receive input AC power having an input AC voltage, a backup power input configured to be coupled to a backup power source and to receive backup DC power from the backup power source and provide DC power to the backup power source for charging, a positive DC bus and a negative DC bus, the positive and negative DC busses being galvanically coupled to the backup power input, and a converter coupled to the input, the backup power input, and the positive and negative DC busses, the converter including a first inductor, a second inductor, a first converter switch configured to couple the first inductor to a neutral connection, a second converter switch configured to couple the second inductor to the positive DC bus, a third converter switch configured to couple the second inductor to the negative DC bus, and a fourth converter switch configured to couple the second inductor to the backup power input, the sequences of computer-executable instructions including instructions that instruct at least one processor to:

• control the UPS to operate in a backup mode of operation responsive to determining that the acceptable AC power is not available at the input;
• operate, in the backup mode of operation, the first converter switch to provide DC power derived from the backup DC power to the positive DC bus via the first inductor;
• and
• operate, in the backup mode of operation, the fourth converter switch to provide DC power derived from the backup DC power to the negative DC bus via the second inductor.