Modular power supply system

• US 5,576,941 A
• Filed: 08/10/1994
• Issued: 11/19/1996
• Est. Priority Date: 08/10/1994
• Status: Expired due to Fees

• Current Assignee: York Technologies, Inc.
• Original Assignee: York Technologies, Inc.
• Inventors: Nguyen, Chien, Johns, Douglas A.
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): Riley, Shawn
• Application Number:
  US08/286,838
• Time in Patent Office: 832 Days
• Field of Search: 363/41, 363/19, 363/21, 363/56, 363/24, 363/26, 363/25, 363/91, 363/97, 363/133, 363/135, 323/222
• US Class Current: 363/21.07
• CPC Class Codes: H02J 9/061 for DC powered loads
• CPC Class Codes: H02J 9/062 for AC powered loads

Abstract

A modular power supply system (10) is provided for providing a multiplicity of output voltages from a plurality of respective converter modules (70a-70n). Each of the converter modules (70a-70n) has an input coupled to a DC high voltage bus (22) from which a respective output voltage is generated. The voltage supplied on DC bus (22) is generated by a power factor corrected boost converter circuit (20) which is coupled to an AC input source (12). Further, a battery backup module (40) is coupled to the high voltage DC bus (22) for supplying backup power whenever the bus voltage drops below a predetermined level.

Claims

1. A power supply, comprising:

a. switching means for generating an oscillation signal responsive to a switching control signal;

b. inverter means coupled to said switching means for converting a direct current voltage of a first magnitude to an output voltage of a second magnitude responsive to said oscillation signal, said inverter means including an inverter transformer having a winding structure adapted to provide a controlled leakage reactance for maintaining stable circuit conditions, said inverter transformer having a primary winding coupled to said switching means for coupling said oscillation signal thereto;

c. pulse width modulator means coupled to said switching means for generating said switching control signal responsive to at least one feedback signal and an absence of an inhibit signal; and

,

d. control means coupled to said pulse width modulator means for generating an inhibit signal for terminating said switching control signal responsive to said direct current voltage first magnitude being less than a predetermined value, said predetermined value being greater than zero.

2. The power supply as recited in claim 1 where said switching means includes a resonate switching circuit coupled to said primary winding of said inverter transformer, said resonate switching circuit including at least a pair of transistors, each of said pair of transistors being coupled to opposing ends of said primary winding of said inverter transformer and having a capacitance in parallel relation therewith.

3. The power supply as recited in claim 1 where said switching means includes (1) at least one switching element having an interruptable conduction path therethrough, one end of said interruptable conduction path being coupled to one end of said primary winding of said inverter transformer, and (2) capacitance means coupled in parallel relation with said interruptable conduction path of said switching element for forming a resonant circuit with said primary winding of said inverter transformer.

4. The power supply as recited in claim 1 where said inverter transformer winding structure includes a core, said primary winding being formed by a longitudinally extended insulating substrate wound on said core with a first conductive member having a rectangular cross-sectional contour deposited longitudinally on said insulating substrate, whereby a dimension between consecutive turns of said primary winding is defined by a thickness dimension of at least a portion said insulating substrate.

5. The power supply as recited in claim 4 where said insulating substrate is formed by a plastic material composition.

6. The power supply as recited in claim 4 where said inverter transformer winding structure includes a secondary winding coupled to said pulse width modulator means to provide said feedback signal thereto.

7. The power supply as recited in claim 6 where said secondary winding is formed by a second conductive member having a rectangular cross-sectional contour deposited longitudinally on said insulating substrate, said second conductive member being deposited in spaced parallel relation with respect to said first conductive member.

8. The power supply as recited in claim 7 where said inverter transformer winding structure further includes a plurality of blocking members disposed on opposing sides of each of said first and second conductive members.

9. The power supply as recited in claim 7 where said first and second conductive members are deposited within respective longitudinally extended spaced parallel recesses disposed on a surface of said insulating substrate.

10. The power supply as recited in claim 1 further comprising rectifier means for generating said first direct current voltage, said rectifier means having an input coupled to an AC voltage source.

11. A power supply, comprising:

a. rectification means having an input coupled to an alternating current voltage source for deriving a first direct current voltage therefrom;

b. voltage boost means having an input coupled to said rectification means for increasing a magnitude value of said first direct current voltage to a second direct current voltage responsive to an oscillation signal applied to a control input terminal of said boost voltage means, said second direct current voltage having a greater magnitude than said magnitude value of said first direct current voltage, said voltage boost means including an inductor having a predetermined inductive reactance, said inductor having one end thereof coupled to said control input terminal;

c. pulse width modulator means for generating said oscillation signal responsive to a plurality of control parameter signals, said pulse width modulator means having an output coupled to said control input terminal of said voltage boost means;

d. control means having an output coupled to an input of said pulse width modulator means for varying a duty cycle of said oscillation signal responsive to a control parameter signal, said control means including inhibit signal generation means having a first input coupled to said rectification means, and an output coupled to said pulse width modulator means for inhibiting generation of said oscillation signal responsive to a magnitude of said alternating current voltage being less than a predetermined value, said predetermined value being greater than zero.

12. The power supply as recited in claim 11 where said control means includes inhibit signal generation means having a first input coupled to said rectification means, and an output coupled to said pulse width modulator means for inhibiting generation of said oscillation signal responsive to a magnitude of said alternating current voltage being less than a predetermined value

13. The power supply as recited in claim 11 where inhibit signal generation means includes a second input coupled to said voltage boost means for inhibiting generation of said oscillation signal responsive to said magnitude of said second direct current voltage being greater than a predetermined value.

14. A modular power supply system, comprising:

a. a DC voltage bus;

b. boost converter means having a first input coupled to a power source for generating a first DC voltage signal from an input line voltage supplied by said power source, said boost converter means having an output connected to said DC voltage bus for coupling said first DC voltage signal to said DC voltage bus, said boost converter being operable responsive to a first control voltage signal coupled to a second input thereof;

c. at least one converter module having a first input coupled to said DC voltage bus for converting said first DC voltage signal to a second DC voltage signal, said second DC voltage signal being of a different magnitude than a magnitude of said first DC voltage signal, said at least one converter module being operable responsive to a second control voltage signal coupled to a second input thereof;

d. a battery backup module having a first input and an output coupled to said DC voltage bus for generating a third DC voltage signal responsive to said magnitude of said first DC voltage signal decreasing in value below a predetermined first reference value, said at least one converter module being operable responsive to said second control voltage signal coupled to a second input thereof; and

,

e. first control means for generating said first and second control voltage signals and having (1) a first input coupled to said input of said boost converter means for monitoring said input line voltage, (2) a second input coupled to said DC voltage bus for monitoring said first DC voltage signal, (3) a first output coupled to said boost voltage converter means for supplying said first control voltage signal thereto, and (4) second and third outputs respectively coupled to said at least one converter module and to said battery backup module for supplying said second control voltage signal respectively thereto, said first control means including a transformer having a primary winding coupled to said DC voltage bus and a switching circuit coupled to said primary winding for generating an intermittent current therethrough, said transformer having a plurality of secondary windings for generating said first and second control voltage signals, said first control means including bootstrap power supply means having an input coupled to one of said plurality of secondary windings and an output coupled to said first output of said first control means for generating said first control voltage signal, said bootstrap power supply means including means for changing a transformation ratio of said one of said plurality of secondary windings subsequent to an initial starting time period.

15. The modular power supply system as recited in claim 14 where said battery backup module includes:

a. high frequency inverter means having an input coupled to a battery power source for generating said third DC voltage signal responsive to a variable duty cycle oscillation signal;

b. pulse width modulator means powered by said second control voltage signal and having an output coupled to said high frequency inverter for generating said variable duty cycle oscillation signal responsive to a non-inhibit control signal; and

,

c. second control means powered by said second control voltage signal and having an input coupled to said DC voltage bus for generating said non-inhibit control signal responsive to said magnitude of said first DC voltage signal being less than said predetermined first reference value.

16. The modular power supply system as recited in claim 15 where said pulse width modulator means includes (1) means for generating an oscillatory signal, (2) means for varying a duty cycle of said oscillatory signal for generating said variable duty cycle oscillation signal, said duty cycle varying means having an input coupled to said oscillatory signal generating means, and (3) voltage regulation means having an input coupled to said DC voltage bus and an output coupled to said duty cycle varying means for varying said duty cycle responsive to a difference between a magnitude of said third DC voltage and a predetermined second reference value.

17. The modular power supply system as recited in claim 14 where said first control means includes means for disabling said boost converter means responsive to a magnitude of said input line voltage being less than a predetermined third reference value.

18. The modular power supply system as recited in claim 14 where said boost converter generates said first DC voltage at a substantially constant magnitude for input line voltages having an approximating range of 90 to 270 volts.

19. The modular power supply system as recited in claim 18 where said first DC voltage is approximately 390 volts.

20. The modular power supply system as recited in claim 19 where said third DC voltage is approximately 360 volts.

21. The modular power supply system as recited in claim 14 where said boost converter means includes:

a. rectifier means having an input coupled to said power source for converting said line input voltage to an input DC voltage;

b. voltage boost means having an input coupled to an output of said rectifier means for increasing a magnitude value of said input DC voltage to generate said first DC voltage signal responsive to an oscillation signal, said first DC voltage signal having a substantially constant magnitude value;

c. pulse width modulator means having an output coupled to said voltage boost means for generating said oscillation signal responsive to drive signal; and

,

d. power factor correction means having an input coupled to said input of said rectification means and an output coupled to said pulse width modulator means for generating said drive signal in timed relationship with respect to said input line voltage to minimize a phase difference between said input line voltage and an input line current.

22. The modular power supply system as recited in claim 21 where said voltage boost means includes:

a. at least one diode having a cathode coupled to said DC voltage bus;

b. an inductor having a predetermined inductive reactance, said inductor having a first end coupled to said output of said rectifier means and a second end coupled an anode of said diode for generating a boost voltage responsive to a switching current signal; and

,

c. switching means coupled to said second end of said inductor for generating said switching current signal responsive to said oscillation signal.

23. The modular power supply system as recited in claim 14 further comprising a plurality of converter modules, each of said plurality of converter modules having an input coupled to said DC voltage bus.

24. A modular power supply system, comprising:

a. a DC voltage bus;

b. control means having an input coupled to said DC voltage bus for generating a low voltage bias signal responsive to an absence of a first logic signal, said control means including voltage generating means coupled to said DC voltage bus for generating said low voltage bias signal at an output thereof responsive to said absence of said first logic signal, and first logic means having an output coupled to said voltage generating means and a pair of input terminals for generating said first logic signal responsive to concurrent receipt of a second logic signal and a third logic signal respectively at said pair of input terminals;

c. boost converter means having an input coupled to a power source for generating a first DC voltage signal from an input line voltage supplied by said power source, said boost converter means having an output connected to said DC voltage bus for coupling said first DC voltage signal to said DC voltage bus, said boost converter means including (1) a first pulse width modulator having a power input coupled to said output of said voltage generating means for generating a first drive signal on an output thereof responsive to said voltage bias signal, (2) voltage boost means having a first input coupled to said power source and a second input coupled to said output of said first pulse width modulator for generating said first DC voltage signal responsive to said first drive signal, and (3) second logic means having an input coupled to said power source and an output coupled to a respective one of said pair of input terminals of said first logic means for generating said second logic signal responsive to a magnitude of said input line voltage being less than a first predetermined value;

d. at least one converter module having an input coupled to said DC voltage bus for converting said first DC voltage signal to a second DC voltage signal, said second DC voltage signal being of a magnitude different than a magnitude of said first DC voltage signal, said converter module including a second pulse width modulator having a power input coupled to said output of said voltage generating means for generating a second drive signal on an output thereof responsive to said voltage bias signal, and first inverter means having a first input coupled to said DC voltage bus and a second input coupled to said output of said second pulse width modulator for generating said second DC voltage signal responsive to said second drive signal; and

,

e. a battery backup module having an input and an output coupled to said DC voltage bus for generating a third DC voltage signal responsive to said magnitude of said first DC voltage signal decreasing in value below a predetermined first reference value, said battery backup module including (1) a third pulse width modulator having a power input coupled to said output of said voltage generating means for generating a third drive signal on an output thereof responsive to said voltage bias signal, (2) second inverter means having an output coupled to said DC voltage bus, a first input coupled to an external battery voltage source and a second input coupled to said output of said third pulse width modulator for generating said third DC voltage signal responsive to said third drive signal, and (3) means for generating an interlock signal responsive to said battery backup module being installed in said modular power supply system, said interlock signal being coupled to a respective one of said pair of input terminals of said first logic means for generating said third logic signal responsive to said interlock signal indicating an absence of said battery backup module, whereby generation of each of said first, second and third DC voltages are simultaneously inhibited responsive to said generation of said first logic signal.

25. The modular power supply system as recited in claim 24, where said converter module includes means for sharing load current between a plurality of such converter modules.