Redundant power system and power supply therefor

• US 6,493,243 B1
• Filed: 01/25/2002
• Issued: 12/10/2002
• Est. Priority Date: 12/01/1999
• Status: Expired due to Fees

• Current Assignee: Tracewell Electronics, Inc.
• Original Assignee: Acme Electric Corp. (Hubbell, Inc.)
• Inventors: Real, Richmond Andrew
• Primary Examiner(s): Patel, Rajnikant B.
• Application Number:
  US10/057,713
• Time in Patent Office: 319 Days
• Field of Search: 363/17, 363/19, 363/20, 363/72, 363/80, 363/81, 363/56, 363/53, 363/60, 307/66, 307/53, 307/55, 307/58, 307/82, 307/44, 307/48
• US Class Current: 363/17
• CPC Class Codes: H02J 9/062 for AC powered loads

Abstract

A redundant power system includes plural load-sharing power supplies connected to a common AC output bus. Identical circuitry is provided in each supply to control the redundant operation and is connected to each of the others via a common redundancy bus. An arbitration circuit in each supply selects a master power supply based on which supply detects the lack of a master supply first via the redundancy bus. A synchronization circuit in each slave supply synchronizes the polarity of the respective AC output with that of the master supply via the redundancy bus. A redundant bias circuit in each supply provides operating power to the redundancy circuitry in the respective supply from a common bulk voltage provided on the redundancy bus. A soft-start circuit in each supply allows all the supplies to start producing power at the AC output bus in unison. An overvoltage correction circuit in each supply detects an overvoltage on the AC output bus and shuts down only the supply which is causing the overvoltage.

Claims

1. A power supply for operation in a redundant power system, the power supply comprising:

a power section comprising a power output for sharing a load with at least one other power supply;

a redundant circuit controlling the power section for cooperation with a corresponding redundant circuit of the at least one other power supply, the redundant circuit operating as determined by a local master/slave status as one of a master and a slave;

a common master-present connection for connection to a corresponding common master-present connection of the at least one other power supply; and

arbitration logic in communication with the common master-present connection, wherein if the arbitration logic senses a master-not-present signal at the common master-present connection, then the arbitration logic sets the local master/slave status to master and transmits a master-present signal to the common master-present connection, and wherein if the arbitration logic senses a master-present signal at the common master-present connection and the local master/slave status is not set to master, then the arbitration logic sets the local master/slave status to slave.

2. The power supply according to claim 1, wherein the arbitration logic comprises:

a master-present sense circuit for sensing a signal at the common master-present connection;

a master-present transmit circuit for transmitting a signal to the common master-present connection; and

a redundancy controller comprising a master-present input/output connected to both the master-present sense circuit and the master-present transmit circuit, the redundancy controller setting the local master/slave status, wherein the redundancy controller sets the master-present input/output to operate as an output when the local master/slave status is set to master, and wherein the redundancy controller sets the master-present input/output to operate as an input when the local master/slave status is set to slave.

3. The power supply according to claim 1, further comprising a common polarity connection for connection to a corresponding common polarity connection of the at least one other power supply;

and wherein the redundant circuit comprises a synchronization circuit which reads a polarity value at the common polarity connection, wherein if the local master/slave status is set to master then the synchronization circuit transmits a master polarity signal to the common polarity connection and the arbitration logic compares the master-polarity signal to the polarity value and upon detecting a dissimilarity sets the local master/slave status to slave.

4. The power supply according to claim 1, further comprising:

a common bias connection for connection to a corresponding common bias connection of the at least one other power supply; and

a redundant bias circuit for contributing to a common bias voltage at said common bias connection, the redundant bias circuit providing operating power to the redundant circuit;

wherein the redundant bias circuit is adapted to provide the operating power to the redundant circuit from a local bias voltage and to alternatively provide the operating power to the redundant circuit from the common bias connection when the local bias voltage is unavailable.

5. A redundant power system comprising:

a plurality of power supplies each connected to a common master-present bus and a common AC output bus;

each of the plurality of power supplies comprising;

an AC output connected to the common AC output bus;

a redundant circuit for redundantly operating the power supply in cooperation with the respective redundant circuits of each of the other power supplies, the redundant circuit operating as determined by a local master/slave status as one of a master and a slave; and

arbitration logic in communication with the common master-present bus, wherein if the arbitration logic senses a master-not-present signal on the common master-present bus, then the arbitration logic sets the local master/slave status to master and transmits a master-present signal to the common master-present bus node, and wherein if the arbitration logic senses a master-present signal on the master bus and the local master/slave status is not set to master, then the arbitration logic sets the local master/slave status to slave.

6. A power supply for operation in a redundant power system, the power supply comprising:

a power section comprising an AC output and a polarity circuit connected to control polarity of a voltage at the AC output;

a synchronization circuit for synchronizing the polarity circuit with a polarity circuit of at least one other power supply;

an amplitude circuit connected to control amplitude of the voltage at the AC

output; and

a controller connected to operate the amplitude circuit and the polarity circuit so as to obtain a desired waveform at the AC output.

7. The power supply according to claim 6 further comprising:

a common bias connection for connection to a corresponding common bias connection of the at least one other power supply; and

a redundant bias circuit for contributing to a common bias voltage at said common bias connection, the redundant bias circuit providing operating power to the synchronization circuit;

wherein the redundant bias circuit is adapted to provide the operating power to the synchronization circuit from a local bias voltage and to alternatively provide the operating power to the synchronization circuit from the common bias connection when the local bias voltage is unavailable.

8. The power supply according to claim 6, wherein the power section further comprises a start-up cycle, the power supply further comprising:

a start-ready connection for connection to a corresponding start-ready connection of the at least one other power supply; and

a soft-start circuit for transmitting a not-ready signal to the start-ready connection until the start-up cycle has completed, wherein the soft-start circuit disrupts the operation of the AC output until the soft-start circuit senses no not-ready signal at the start-ready connection.

9. The power supply according to claim 6, wherein the power section further comprises a pulse-width modulation signal and the AC output is adapted for connection to a corresponding AC output of the at least one other power supply, the power supply further comprising:

an overvoltage detection circuit sensing a peak voltage level of the AC output, wherein the overvoltage detection circuit transmits an overvoltage signal if the peak voltage level exceeds a predetermined peak voltage level;

a duty-cycle detection circuit sensing-a duty cycle level of the pulse-width modulation signal, wherein the duty-cycle detection circuit transmits a maximum-duty-cycle signal when the duty-cycle level of the pulse-width modulation signal exceeds a predetermined maximum duty-cycle level; and

an overvoltage correction circuit in communication with the overvoltage detection circuit and in communication with the duty-cycle detection circuit, wherein the overvoltage latch circuit disrupts the operation of the AC output when the overvoltage correction circuit simultaneously detects both the overvoltage signal and the maximum-duty-cycle signal.

10. The power supply according to claim 9, wherein the overvoltage correction circuit comprises an overvoltage latch that continues to disrupt the operation of the AC output after the overvoltage signal and the maximum-duty-cycle signal are no longer detected by the overvoltage correction circuit.

11. A power supply for operation in a redundant power system, the power supply comprising:

a local master/slave status settable to one of master and slave;

a common polarity connection for connection to a corresponding common polarity connection of at least one other power supply;

synchronization logic which reads a polarity value at the common polarity connection, and if the local master/slave status is set to master, then the synchronization logic transmits a master polarity signal to the common polarity connection; and

a power section comprising an AC output and a polarity control connected to the synchronization logic for setting a polarity of the AC output according to the polarity value at the common polarity connection, the polarity control being connected to the synchronization logic for providing the master polarity signal to the synchronization logic.

12. The power supply according to claim 11, wherein the synchronization logic comprises:

a synchronization read circuit comprising a synchronization read input connected to the common polarity connection for reading the polarity value, the synchronization read circuit further comprising a synchronization read output for transmitting the polarity value;

a redundancy controller being connected to the polarity circuit of the power section, the redundancy controller comprising a local master-polarity output for transmitting the master polarity signal from the polarity circuit of the power section, the redundancy controller further comprising a polarity-average input connected to the synchronization read output, the redundancy controller further comprising a local master/slave status output for transmitting the local master/slave status, wherein the local master-slave status is set be the redundancy controller; and

a synchronization transmit circuit comprising a synchronization transmit input connected to the local master-popularity output, the synchronization circuit further comprising a synchronization transmit control input connected to the local master/slave status output of the redundancy controller for controlling the operation of the synchronization transmit circuit, the synchronization transmit circuit further comprising a synchronization transmit output for transmitting the master polarity signal to the common polarity connection.

13. The power supply according to claim 11, further comprising:

a common bias connection for connection to a corresponding common bias connection of the least one other power supply; and

a redundant bias circuit for contributing to a common bias voltage at said common said common bias connection, the redundant bias circuit providing operating power to the polarity logic;

wherein the redundant bias circuit is adapted to provide the operating power to the polarity logic from a local bias voltage and to alternatively provide the operating power to the polarity logic from the common bias connection when the local bias voltage is unavailable.

14. The power supply according to claim 11, wherein the power section further comprises a start-up cycle, the power supply further comprising:

a start-ready connection for connection to a corresponding start-ready connection of at the least one other power supply; and

a soft-start circuit for transmitting a not-ready signal to the start-ready connection until the start-up cycle has completed, wherein the soft-start circuit disrupts the operation of the AC output until the soft-start circuit senses no not-ready signal at the start-ready connection.

15. The power supply according to claim 11, wherein the power section further comprises a pulse-width modulation signal and the AC output is adapted for connection to a corresponding AC output of the at least one other power supply, the power supply further comprising:

an overvoltage detection circuit sensing a peak voltage level of the AC output, wherein the overvoltage detection circuit transmits an overvoltage signal if the peak voltage level exceeds a predetermined peak voltage level;

a duty-cycle detection circuit sensing a duty cycle level of the pulse-width modulation signal, wherein the duty-cycle detection circuit transmits a maximum-duty-cycle signal when the duty-cycle level of the pulse-width modulation signal exceeds a predetermined maximum duty-cycle level; and

an overvoltage correction circuit in communication with the overvoltage detection circuit and in communication with the duty-cycle detection circuit, wherein the overvoltage correction circuit disrupts the operation of the AC output when the overvoltage correction circuit detects both the overvoltage signal and the maximum-duty-cycle signal.

16. The power supply according to claim 15, wherein the overvoltage correction circuit comprises an overvoltage latch that continues to disrupt the operation of the AC output after the overvoltage signal and the maximum-duty-cycle signal are no longer detected by the overvoltage correction circuit.

17. A redundant power system comprising a plurality of power supplies each connected to a common polarity bus, each of the plurality of power supplies comprising:

a local master/slave status settable to one of master and slave;

a synchronization circuit which reads a polarity value from the common polarity bus and if the local master/slave status is set to master, then the synchronization circuit transmits a master polarity signal to the common polarity bus; and

a power section comprising an AC output and a polarity control connected to set the polarity of the AC output according to the polarity value of the common polarity bus.

18. A power supply for operation in a redundant power system, the power supply comprising:

a redundant circuit for cooperation with a corresponding redundant circuit of at least one other power supply;

a power section for providing a local bias voltage;

a common bias connection for connection to a corresponding common bias connection of the at least one other power supply; and

a redundant bias circuit for contributing to a common bias voltage at said common bias connection, the redundant bias circuit providing operating power to the redundant circuit;

wherein the redundant bias circuit is adapted to provide the operating power to the redundant circuit from the local bias voltage and to alternatively provide the operating power to the redundant circuit from the common bias connection when the local bias voltage is unavailable.

19. The power supply according to claim 18, wherein the redundant bias circuit further comprises a redundant bias regulator connected between the common bias connection and redundant circuit to provide the operating power as a regulated voltage.

20. The power supply according to claim 19, wherein the redundant bias circuit further comprises a bias clamp circuit connected between the redundant bias regulator and the common bias connection to protect the redundant bias regulator from excessive voltages.

21. The power supply according to claim 18, wherein the power section further comprises a power section comprising a local bias connection for providing the local bias voltage, and the power supply further comprising a bias diode connected between the local bias connection and the common bias connection for performing a logical OR operation of the local bias voltage onto the common bias connection.

22. A redundant power system comprising a plurality of power supplies each connected to a common bias bus, each of the plurality of power supplies comprising:

a redundant circuit for cooperation with a corresponding redundant circuit of each of the other power supplies;

a power section for providing a local bias voltage;

a redundant bias circuit for contributing to a common bias voltage at the common bias bus, the redundant bias circuit providing operating power to the redundant circuit; and

a bias diode for performing a logical OR operation of the local bias voltage onto the common bias connection;

wherein the redundant bias circuit is adapted to provide the operating power to the redundant circuit from the local bias voltage and to alternatively provide the operating power to the redundant circuit from the common bias connection when the local bias voltage is unavailable.

23. A power supply for operation in a redundant power system, the power supply comprising:

a power section comprising an AC output and a start-up cycle;

a start-ready connection for connection to a corresponding start-ready connection of at least one other power supply; and

a soft-start circuit for transmitting a not-ready signal to the start-ready connection until the start-up cycle has completed, wherein the soft-start circuit disrupts the operation of the AC output until the soft-start circuit senses no not-ready signal at the start-ready connection.

24. The power supply of claim 23, wherein the not-ready signal comprises shorting of the start-ready connection to a ground reference.

25. The power supply of claim 23, wherein the soft-start circuit further comprises a start relay comprising relay contacts connected between the start-ready connection and a source of the not-ready signal.

26. The power supply of claim 23, wherein the soft-start circuit further comprises a soft-start latch which prevents subsequent disruption of the AC output by the soft-start circuit after the soft-start circuit senses no not-ready signal at the start-ready connection.

27. The power supply of claim 23, wherein the power section further comprises a pulse-width modulation signal and wherein the AC output for connection to a corresponding AC output of the at least one other power supply, the power supply further comprising:

an overvoltage detection circuit sensing a peak voltage level of the AC output, wherein the overvoltage detection circuit transmits an overvoltage signal if the peak voltage level exceeds a predetermined peak voltage level;

a duty-cycle detection circuit sensing a duty cycle level of the pulse-width modulation signal, wherein the duty-cycle detection circuit transmits a maximum-duty-cycle signal when the duty-cycle level of the pulse-width modulation signal exceeds a predetermined maximum duty-cycle level; and

an overvoltage correction circuit in communication with the overvoltage detection circuit and in communication with the duty-cycle detection circuit, wherein the overvoltage correction circuit disrupts the operation of the AC output when the overvoltage correction circuit detects both the overvoltage signal and the maximum-duty-cycle signal.

28. A power supply comprising:

a power section comprising a pulse-width modulation signal and an AC output for connection to a corresponding AC output of at least one other power supply;

an overvoltage detection circuit sensing a peak voltage level of the AC output, wherein the overvoltage detection circuit transmits an overvoltage signal if the peak voltage level exceeds a predetermined peak voltage level;

a duty-cycle detection circuit sensing a duty cycle level of the pulse-width modulation signal, wherein the duty-cycle detection circuit transmits a maximum-duty-cycle signal when the duty-cycle level of the pulse-width modulation signal exceeds a predetermined maximum duty-cycle level; and

an overvoltage correction circuit in communication with the overvoltage detection circuit and in communication with the duty-cycle detection circuit, wherein the overvoltage correction circuit disrupts the operation of the AC output when the overvoltage correction circuit detects both the overvoltage signal and the maximum-duty-cycle signal.

29. The power supply of claim 28, wherein the overvoltage correction circuit comprises a overvoltage latch that continues to disrupt the operation of the AC output after the overvoltage signal and the maximum-duty-cycle signal are no longer detected by the overvoltage correction circuit.

30. The power supply of claim 28, wherein the overvoltage detection circuit comprises a rectifier connected to the AC output.