US 4,366,389 A · Continuously operating standby A-C power system

Abstract

A continuously operating standby A-C power system which uses a single loop responsive to the system's input and output A-C voltages, the voltage of the battery included in the standby portion of the supply and the amplitude and frequency of the input A-C voltage for controlling the phase relationship between the input and output voltages. When the input A-C voltage is acceptable in both amplitude and frequency, the loop is closed. When the voltage becomes unacceptable, the loop opens. When the voltage returns to acceptability after a period of nonacceptability, circuitry is included in the system for slowly closing the loop.

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Drawings

Claims20

Dependent claims

A power-supply system having an input and an output connected by an A-C voltage transmission means for providing at said output a regulated A-C voltage, which comprises:

(a) sensing means to sense the voltage waves in said transmission means on the input and output sides of said system, said sensing means being directly connected to said transmission means whereby there is no substantial phase shift between said transmission means and said sensing means,
(b) means responsive only to said input A-C voltage wave for determining the occurrence in said input voltage wave of at least one of a predetermined number of undesirable conditions, said means generating a first signal of predetermined amplitude upon said occurrence and a second signal of predetermined amplitude upon the nonoccurrence of said undesirable conditions,
(c) a switch means interposed in said transmission means between said input and output thereof, said switch means normally operating in a closed condition and being adapted to be selectively inhibited, upon the occurrence of said first signal, to thereby prevent transmission of said input A-C voltage wave to said output,
(d) a standby power system including a bidirectional inverter connected between a battery and said output and adapted to supply from said battery an A-C voltage wave of predetermined frequency to said output during periods when said switch means is inhibited, and
(e) a phase control means operating in a loop between said input and said output, said loop being the only loop in said system and fully closed when said switch means operates in a closed condition, said phase control means responsive when said loop is fully closed to said input and output voltage waves and said second signal for controlling the phase relationship between said voltage waves, said phase control means responsive to said first signal for fully opening said fully closed loop and for controlling said frequency of said A-C voltage wave supplied by said standby power system.

2 more elements

A power-supply system having an input and an output connected by an A-C voltage transmission means for providing at said output a regulated A-C voltage, which comprises:

(a) sensing means to sense the voltage waves in said transmission means on the input and output sides of said system, said sensing means being directly connected to said transmission means whereby there is no substantial phase shift between said transmission means and said sensing means,
(b) a switch means interposed in said transmission means between said input and output thereof, said switch means normally operating in a closed condition and being adapted to be selectively inhibited, upon the occurrence of at least one of a predetermined number of undesirable conditions in said input voltage wave, to thereby prevent transmission of said input A-C voltage wave to said output,
(c) a standby power system including a bidirectional inverter connected between a battery and said output and adapted to supply from said battery an A-C voltage wave of predetermined frequency to said output during periods when said switch means is inhibited, and
(d) a phase control means operating in a loop between said input and said output, said loop being the only loop in said system and fully closed when said switch means operates in a closed condition, said phase control means responsive when said loop is fully closed to said input and output voltage waves for controlling the phase relationship between said voltage waves, said phase control means responsive to the occurrence of at least one of said predetermined number of undesirable conditions for fully opening said fully closed loop and for controlling said frequency of said A-C voltage wave supplied by said standby power system.

1 more element

A continuously operating standby power supply and battery charging system having an input and an output and an A-C transmission means connected therebetween for supplying at said output a regulated A-C voltage which comprises:

(a) an inverter adapted to permit flow of current in both directions therethrough;
(b) circuit means to maintain said inverter continuously connected to said output;
(c) circuit means to connect a storage battery to said inverter in such a manner that flow of current through said inverter in one direction effects supplying of energy from said battery to said line, and flow of current through said inverter in the opposite direction effects charging of said battery from said line;
(d) sensing means to sense the voltage waves in said transmission means on the input and output sides of said system, said sensing means being directly connected to said transmission means whereby there is no substantial phase shift between said transmission means and said sensing means;
(e) a switch means interposed in said transmission means between said input and output thereof, said switch means normally operating in a closed condition and being adapted to be selectively inhibited, upon the occurrence of at least one of a predetermined number of undesirable conditions in said input voltage wave, to thereby prevent transmission of said input A-C voltage wave to said output;
and
(f) a phase control means operating in a loop between said input and said output, said loop being the only loop in said system and fully closed when said switch means operates in a closed condition, said phase control means responsive when said loop is fully closed to said input and output voltage waves and the voltage on said battery for controlling the phase relationship between said voltage waves, said phase control means controlling said phase relationship to effect current flow through said inverter in said one direction when said battery voltage is greater than a reference voltage and to effect current flow through said inverter in said opposite direction when said battery voltage is less than said reference voltage.

4 more elements

Dependencies are inferred from the claim text.

Description10,785 words

Summary1,359 words

#1. Field of the Invention

#The present invention relates to an automatic and continuously operating standby A-C power system and more particularly to circuitry included in such a system for controlling the phase relationships between the voltage at the system's input and output terminals by the use of a single phase control loop which is fully closed when the input A-C voltage is acceptable and fully open when the input A-C voltage is not acceptable and circuitry included therein for slowly closing the loop upon the return of the input A-C voltage to acceptability after a period of nonacceptability.

#2. Description of the Prior Art

Brief description of the drawings4 figures

#FIG. 1 is a block-schematic diagram illustrating one embodiment of the present invention.

#FIG. 2 is a schematic diagram of the phase locked loop and battery charge regulator shown in FIG. 1.

#FIG. 3 is a schematic diagram of the A-C sense circuit shown in FIG. 1.

Detailed description9,362 words

#Referring to FIG. 1 there is shown the block-schematic diagram of an automatic standby A-C power system 10 which supplies uninterrupted 60 Hz A-C power to a load such as a computer. A conventional 60 Hz power line is indicated at 12 having interposed therein a static switch 18. The input terminals of line 12 are indicated at 14 and are adapted to be connected to a suitable source of conventional A-C power such as a central power station. The output terminals of the line 12 are indicated at 16 and are adapted to be connected to the load. Interposed between the static switch 18 and the output terminals 16 is a line inductor L.sub.1.

#Static switch 18 is adapted to open the line automatically in response to various undesired line conditions, for example, during periods when the magnitude of the line voltage is excessively low or when the frequency of the line voltage is higher or lower than predetermined limits. Each of these conditions results from a failure of the conventional A-C power which may occur in the form of a blackout, brownout, interrupt or transient. In the absence of undesired line conditions system 10 operates in a normal or nonfailure mode, whereas in the presence of one or more of such conditions the system operates in a failure mode.

#For the nonfailure operating mode switch 18 conducts in a manner to apply the conventional A-C power to regulator 22. The regulator circuit is comprised of the secondary winding of ferroresonant transformer T.sub.1 and capacitor C.sub.1 connected thereacross to thereby form a tank circuit resonant at 60 Hz. The energy which circulates in this tank circuit is used to provide at output terminals 16 a regulated A-C voltage. Line inductor L.sub.1 provides isolation between the input terminals 14 and the output terminals 16 of the system 10. This isolation allows the voltage at terminals 16 to be relatively insensitive to changes in the voltage at terminals 14. Thus, for the nonfailure operating mode system 10 provides at its output terminals a regulated A-C voltage to the load.

Facts

Application

06/282,872Filed 13 Jul 1981

Granted

28 Dec 1982

Term ended

13 Jul 2001

Estimated · how

Pre-1995 term; greater of 17 years from grant or 20 years from filing when eligible. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification6 codes

H02J 9/062
With automatic change-over , e.g. UPS systems: for AC powered loads
Y02B 70/30
Technologies for an efficient end-user side electric power management and consumption: systems integrating technologies related to power network…
Y04S 20/20
Management or operation of end-user stationary applications or the last stages of power distribution; Controlling, monitoring or operating…
H02J
Power supply and charging

Continuously operating standby A-C power system

Life of this patent

Continuously operating standby A-C power system

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims20

Description10,785 words

Drawings

Classification6 codes

Life of this patent

Description10,785 words