Power factor corrected UPS with improved connection of battery to neutral and methods of operation thereof

• US 6,661,678 B2
• Filed: 05/20/2002
• Issued: 12/09/2003
• Est. Priority Date: 03/29/1993
• Status: Expired due to Fees

• Current Assignee: Eaton Power Quality Corporation (Eaton Corporation PLC.)
• Original Assignee: Powerware Corporation (Eaton Corporation PLC.)
• Inventors: Raddi, William J., Paulakonis, Joseph C., Johnson, Robert W. Jr.
• Primary Examiner(s): Vu, Bao Q.
• Application Number:
  US10/151,449
• Publication Number:
  US 20020130648A1
• Time in Patent Office: 568 Days
• Field of Search: 363/17, 363/40, 363/41, 363/37, 363/47, 363/48, 363/95, 363/98, 363/131, 307/66, 307/64
• US Class Current: 363/37
• CPC Class Codes: H02J 9/062 for AC powered loads
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 1/4208 Arrangements for improving power factor of AC input
• CPC Class Codes: H02M 5/458 using semiconductor devices only
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

An uninterrupted power supply (UPS) device with uninterrupted neutral from input to output utilizes the same converter for converting rectified AC power and battery power to positive and negative high voltage (HV) rails. A simple circuit is utilized for connecting the battery to the conversion components of the PFC circuit without adverse affect on the performance of the PFC circuit, and while holding the battery substantially connected to neutral. In a first embodiment, the circuit comprises a simple combination of four diodes and a pair of high pass capacitors arranged so that in both power line and battery supply modes the battery is balanced around neutral. In a second, preferred embodiment, one terminal of the battery is connected directly to neutral.

Claims

1. An uninterruptible power supply (UPS) apparatus, comprising:

a power factor correcting converter circuit, configured to connect to an AC power source and to a DC power source, that generates a DC output voltage from the AC power source in an AC powered mode and that generates the DC output voltage from the DC power source in a DC powered mode.

2. An uninterruptible power supply (UPS) apparatus, comprising:

a power factor correcting converter circuit, configured to connect to an AC power source and to a DC power source, that generates a DC voltage from respective ones of the AC power source and the DC power source in respective AC powered and DC powered modes; and

an output circuit, coupled to the power factor correcting converter circuit, that generates an AC output from the DC voltage such that the AC output shares a common neutral with the AC power source.

3. An uninterruptible power supply (UPS) apparatus, comprising:

a power factor correcting converter circuit having a neutral configured to connect to an AC power source and to a DC power source, the power factor correcting converter circuit operative to generate a DC voltage with respect to the neutral from respective ones of the AC power source and the DC power source in respective AC powered and DC powered modes; and

an output circuit coupled to the power factor correcting converter circuit and operative to generate from the DC voltage an AC output with respect to the neutral.

4. An uninterruptible power supply (UPS) apparatus, comprising:

a boost converter circuit, configured to connect to an AC power source and to a DC power source, that generates a DC voltage from respective ones of the AC power source and the DC power source in respective AC powered and DC powered modes using at least one common inductor; and

an output circuit, coupled to the converter circuit, that generates an AC output from the DC voltage such that the AC output shares a common neutral with the AC power source.

5. An uninterruptible power supply (UPS) apparatus, comprising:

a power factor correcting converter circuit, configured to connect to an AC power source and to a DC power source, that generates a DC voltage from respective ones of the AC power source and the DC power source in respective AC powered and DC powered modes using at least one common inductor; and

an output circuit, coupled to the power factor correcting converter circuit, that generates an AC output from the DC voltage.

6. An uninterruptible power supply (UPS) apparatus, comprising:

an inductor;

a DC voltage rail;

a switch circuit coupled to the inductor and to the DC voltage rail and operative to transfer power to via the inductor from respective ones of an AC power source and a DC power source in respective AC and DC powered modes to generate a DC voltage at the DC voltage rail; and

an output circuit, coupled to the DC voltage rail, that generates an AC output from the DC voltage, wherein the AC output shares a common neutral with the AC power source.

7. A method of generating an AC output, comprising;

connecting respective ones of an AC power source and a DC power source to an input of a power factor correcting converter circuit in respective AC and DC powered modes to generate a DC voltage with respect to a neutral of the AC power source from respective ones of the AC power source and the DC power source; and

generating an AC output with respect to the neutral from the DC voltage.

8. A method of producing an AC output, comprising:

transferring power to a DC voltage rail from respective ones of an AC power source and a DC power source via a common inductor in AC and DC powered modes to generate a DC voltage at the DC voltage rail; and

generating an AC output from the DC voltage such that the AC output shares a common neutral with the AC power source.