Autonomous uninterruptable power supply apparatus

• US 4,673,826 A
• Filed: 12/20/1984
• Issued: 06/16/1987
• Est. Priority Date: 12/20/1984
• Status: Expired due to Fees

• Current Assignee: AIR FORCE, UNITED STATED OF AMERICA AS REPRESENTED BY THE SECRETARY OF THE
• Sponsoring Entity: AIR FORCE, UNITED STATED OF AMERICA AS REPRESENTED BY THE SECRETARY OF THE
• Inventors: Masson, James H.
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): Ip, Shik Luen Paul
• Time in USPTO: 908 Days
• Field of Search: 307/37, 307/38, 307/39, 307/41, 307/44, 307/46, 307/48, 307/61, 307/63, 307/64, 307/65, 307/66, 307/67, 307/70, 307/71, 307/85, 307/86, 307/87, 307/96, 307/97, 364/494, 364/495, 364/184
• US Class Current: 307/66
• CPC Class Codes: H02J 7/0026 : using safety or protection circuits, e.g. overcharge/discharge disconnection
• CPC Class Codes: H02J 9/062 : involving non rotating DC/AC converters
• CPC Class Codes: Y10T 307/615 : Substitute or emergency source
• CPC Class Codes: Y10T 307/625 : Storage battery or accumulator
• CPC Class Codes: Y10T 307/735 : Attainment of voltage, frequency or phase relationship

Abstract

An autonomous uninterruptable power supply apparatus utilizing a digital processor unit as a control and monitor unit to measure and control input and output parameters in the power supply. A battery charger is utilized to maintain the voltage and current levels with the backup battery supply source which powers an inverter unit that converts the DC power to an AC output.

Claims

1. An autonomous uninterruptable power supply apparatus comprising in combination:

a means for charging, said charging means receiving an AC input signal, said charging means providing a DC output signal,

an inverter means connected directly to said charging means by a DC bus line, said inverter means receiving a DC input signal and providing an AC output signal in response thereto,

a switching means having a switchable first and second input terminal and an output terminal, said first input terminal connected to the output of said inverter means, said second input terminal connected to the input of said charging means by an AC bypass line to receive said AC input signal,

a plurality of DC supply means respectively connected in parallel between said DC bus line and a DC return line, said charging means simultaneously providing a DC output signal to both said inverter means and said plurality of DC supply means, said charging means charging said plurality of DC supply means simultaneously in parallel to respectively maintain a predetermined voltage level thereon, said plurality of DC supply means respectively comprise;

a switch means with a switchable first and second terminal and an output terminal, said first terminal connected to said DC bus line,

a battery means with a positive and negative terminal, said positive terminal connect to said output terminal of said switch means,

a current sensing means connected between said negative terminal and said DC return line, and

an impedance means connected between said second terminal of said switch means and said DC return line, said switch means operating under the control of said control/monitor means, said control/monitor means operating said switch means to said first terminal to charge said battery means, said control/monitor means operating said switch means to said second terminal to test the capacity of said battery means by connecting said impedance means in parallel with said battery means and said current sensing means, and,

a control/monitor means operatively connected to said charging means, said inverter means, said plurality of DC supply means and said switching means, said control/monitor means monitoring the output voltage of said charger means, said inverter means and said plurality of DC supply means, said control/monitor means sensing the current capacity of said plurality of DC supply means, said control/monitor means respectively providing control signals to said charger means, said inverter means, said switch means and said plurality of DC supply means, said control/monitor means providing system status output signals, said control/monitor means comprises;

a data acquisition means to receive the input parameters from said charging means, inverter means, and said plurality of DC supply means, said data acquisition means converting said input parameters from analog to digital to provide digital data,

a central processor means receiving said digital data from said data acquisition means, said central processor means operably connected to a clock means to establish system timing, said central processor means generating output commands,

a programmable read only memory means operably connected to said central processor means, said programmable read only memory means storing operating parameters for use in said central processor means,

a random access memory means operably connected to said central processor means, said random access memory means storing program variables which are used in said central processor means,

a control output interface means operably connected between said central processor means and said charging means, said inverter means, said plurality of DC supply means, and said switching means, said control output interface means applying said output commands from said central processor unit to said charging means, said inverter means, said plurality of DC supply means, and said switching means, and

a status output interface means operably connected to said central processor means to provide system status output signals.