Bi-directional dc-to-dc power converter

• US 6,069,804 A
• Filed: 07/23/1999
• Issued: 05/30/2000
• Est. Priority Date: 07/28/1998
• Status: Expired due to Term

• Current Assignee: SL Auburn, Inc. (Eaton Corporation PLC.), RFL Electronics, Inc. (Hubbell, Inc.), SL Power Electronics Corp. (Steel Partners Holdings LP)
• Original Assignee: Condor D.C. Power Supplies, Inc. (Steel Partners Holdings LP)
• Inventors: Beecroft, John W., Mullett, Charles E., Ingman, Thomas M.
• Primary Examiner(s): HAN, YOUNGHUIE JESSICA
• Application Number:
  US09/359,499
• Time in Patent Office: 312 Days
• Field of Search: 363/17, 363/21, 363/80, 363/97, 363/131, 363/16, 323/222, 323/271, 323/282
• US Class Current: 363/21.14
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: H02M 1/009 having two or more independently controlled outputs for DC-DC converter with intermediate AC H02M3/33561
• CPC Class Codes: H02M 3/33584 Bidirectional converters
• CPC Class Codes: H02M 3/33592 having a synchronous rectifier circuit or a synchronous freewheeling circuit at the secondary side of an isolation transformer
• 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

A multi-output, multi-directional power converter has an input bi-directional switch and at least a first output bi-directional switch, a coupled inductor having an input winding and at least one output winding. The coupled inductor input winding is connected in series with the input voltage source and an input bi-directional switch. Each coupled inductor output winding is connected in series with a corresponding output voltage source such as a capacitor and its respective output bi-directional switch. A clock circuit provides a first and second control signal. Each control signal has a first and second state. The second control signal has a state that is the complement of the first control signal. The first control signal is connected to the input bi-directional switch control terminal and the second control signal is connected to each respective output bi-directional switch control terminal. The input bi-directional switch is driven into a conductive state in response to the first control signal being in a first state and into a non-conductive state in response to the second control signal being in a second state. Each respective output bi-directional switch conduction channel is driven into a conductive state in response to the second control signal being in a first state and into a non-conductive state in response to the second control signal being in a second state. In an alternative embodiment, a resonant transition control means senses the coupled inductor input and output winding currents and the output voltage and adjusts the clock frequency to provide operation in a resonant transition mode.

Claims

1. A bi-directional power converter having an input coupled to an input voltage source and an output coupled to a first output voltage source comprising:

an input bi-directional switch, a FET, having a conduction channel and a control terminal, and

an output bi-directional switch, a FET, having a conduction channel and a control terminal,

a coupled inductor having an input winding and an output winding, the coupled inductor input winding being coupled to the output winding,

the coupled inductor input winding being connected in series with the input voltage source and the input bi-directional switch conduction channel,

the coupled inductor output winding being connected in series with the first output voltage source and the output bi-directional switch conduction channel,

a clock circuit providing first and second control signals, each control signal having a first and second state, the second control signal having a state that is the complement of the first control signal,

the first control signal first state duration followed by the second control signal first state duration forming a substantially fixed clock period, the first control signal being coupled to the input bi-directional switch control terminal and the second control signal being coupled to the output bi-directional switch control terminal,

the input bi-directional switch conduction channel being driven into a conductive state in response to the first control signal being in a first state and into a non-conductive state in response to the first control signal being in a second state,

the output bi-directional switch conduction channel being, driven into a conductive state in response to the second control signal being in a first state and into a non-conductive state in response to the second control signal being in a second state.

2. The bi-directional dc-to-dc power converter of claim 1 wherein the first output voltage source further comprises an output capacitor.

3. The bi-directional power converter of claim 1 wherein the first output voltage source further comprises an output capacitor in parallel with a load.

4. The bi-directional power converter of claim 1 wherein the clock circuit provides a clock signal with a substantially fixed period to set the output of a latch circuit to a first state, the output of the latch circuit driving the first control signal high, a first amplifier circuit that senses the output voltage of the converter, and compares a portion of the output voltage with a precision internal reference voltage to provide an error voltage, a second amplifier circuit that senses the input winding current rise in the input winding as a ramp current voltage, a comparator circuit that compares the ramp current voltage with the error voltage, and provides, a reset signal to the latch circuit to set the latch circuit output to a second state in response to the ramp current voltage exceeding the error voltage, the second state output of the latch circuit driving the first control signal low, the latch circuit output being set to the first state on receiving the next clock signal.

5. The bi-directional power converter of claim 4 wherein the coupled inductor has a first and a second output winding, each respective output winding being coupled through a respective bi-directional switch to a respective output voltage source, and wherein, each respective output voltage source further comprises a charged output capacitor.

6. The bi-directional power converter of claim 4 wherein the coupled inductor has a first and a second output winding, each respective output winding being coupled through a respective bi-directional switch to a respective output voltage source, and wherein, each respective output voltage source further comprises a charged output capacitor in parallel with a respective load.

7. The bi-directional power converter of claim 4 wherein the coupled inductor has a first and a second output winding, and wherein, each respective output winding is isolated from the input winding, each respective output winding being coupled to a respective output bi-directional switch conduction channel to drive a respective output voltage sources.

8. The bi-directional power converter of claim 4 wherein the coupled inductor has a first and a second output winding, and wherein,

each respective output winding is isolated from the input winding, each respective output winding being coupled to a respective output bi-directional switch conduction channel to drive a respective output voltage source,

each respective bi-directional switch control terminal being coupled to be responsive to drive its corresponding conduction channel into a conductive state in response to the second control signal being in a first state and into a non-conductive state in response to the second control signal being in a second state.

9. The bi-directional power converter of claim 1 wherein the coupled inductor has a first and a second output winding, each respective output winding being coupled through a respective bi-directional switch to a respective output voltage source.

10. A multi-output, multi-directional power converter having an input coupled to an input voltage source comprising:

an input bi-directional switch, a FET, having a conduction channel and a control terminal, and

at least a first and a second output bi-directional switch, FETs, each having a conduction channel and a control terminal,

a coupled inductor having an input winding and at least two output windings, the coupled inductor input winding being tightly coupled to each output winding,

the coupled inductor input winding being coupled in series with the input voltage source and the input bi-directional switch conduction channel,

each coupled inductor output winding being coupled in series with a corresponding output voltage source and its respective output bi-directional switch conduction channel,

a clock circuit providing a first and second control signal, each control signal having a first and second state, the second control signal having a state that is the complement of the first control signal,

the first control signal first state duration followed by the second control signal first state duration forming a substantially fixed clock period, the first control signal being coupled to the input bi-directional switch control terminal and the second control signal being coupled to each respective output bi-directional switch control terminal,

the input bi-directional switch conduction channels being driven into a conductive state in response to the first control signal being in a first state and into a non-conductive state in response to the first control signal being in a second state,

each respective output bi-directional switch conduction channels being driven into a conductive state in response to the second control signal being in a first state and into a non-conductive state in response to the second control signal being in a second state.

11. The power converter of claim 10 wherein one or more of the output voltage sources further comprise an output capacitor.

12. The power converter of claim 10 one or more of the output voltage sources further comprises an output capacitor in parallel with a load.

13. A power converter having an input coupled to an input voltage source having a first and second terminal comprising:

a coupled inductor having an input winding and at least two output windings, each input and output winding having a first and second terminal, the coupled inductor input winding being tightly coupled to each output winding, the input winding first terminal being connected to the voltage source first terminal,

an input bi-directional switch, a FET, having a conduction channel and a control terminal, the conduction channel having first and second terminals, the conduction channel first terminal being connected to the input winding second terminal and the conduction channel second terminal being connected to the voltage source second terminal,

at least a first and second output bi-directional switch, FETs, each having a conduction channel and a control terminal, said each conduction channel having a respective first and second terminal,

the first output winding being coupled in series with the first output voltage source and the first output bi-directional switch conduction channel,

a battery having a first and a second terminal, the second output winding first terminal being coupled to the first terminal of the battery, the second output bi-directional switch conduction channel first terminal being connected to the second output winding second terminal and the conduction channel second terminal being connected to the battery second terminal,

a clock circuit providing a first and second control signal, each control signal having a first and second state, the second control signal having a state that is the complement of the first control signal, the first control signal first state duration followed by the second control signal first state duration forming a substantially fixed clock period, the first control signal being coupled to the input bi-directional switch control terminal and the second control signal being coupled to the first and second output bi-directional switch control terminals,

the input bi-directional switch conduction channel being driven into a conductive state in response to the first control signal being in a first state and into a non-conductive state in response to the first control signal being in a second state, each respective output bi-directional switch conduction channel being driven into a conductive state in response to the second control signal bring in a first state and into a non-conductive state in response to the second control signal being in a second state.

14. The converter of claim 13 wherein the second output winding first terminal is connected in series with the battery first terminal via the series combination of a charging diode and a current limiting resistor;

whereby, the second output winding provides charging current through the charging diode to charge the battery.

15. The converter of claim 13 further comprising:

a blocking diode having a cathode terminal and an anode terminal,

the battery first terminal being connected to the blocking diode anode terminal, the blocking diode cathode terminal being connected to the second output winding first terminal,

whereby, the battery provides power to the second output winding through the blocking diode to support continued operation of the dc-to-dc converter in response to a loss of power from the input voltage source.

16. The converter of claim 15 wherein a controlled directional current regulator has been added in series with the battery and the blocking diode.

17. The converter of claim 13 further comprising:

a blocking diode having a cathode and an anode terminal, the diode cathode terminal being connected to the second output winding first terminal,

an inductor having a first terminal connected to the battery first terminal, and a second terminal connected to the diode anode terminal, and

an input voltage source monitor circuit for monitoring the input voltage of the input voltage source and for outputting an enable signal in response to the input voltage dropping below a first threshold and for removing the enable signal in response to the input voltage rising above a second threshold;

a semiconductor switch having a conduction channel having a first and second terminal, and control terminal, the semiconductor switch conduction channel first terminal being connected to the inductor second terminal and the semiconductor switch conduction channel second terminal being connected to the battery second terminal, the semiconductor switch control terminal being driven by the first control signal in response to an enable signal;

whereby, the blocking diode, inductor and semiconductor switch operate as a boost converter to extract power from the battery and to provide power to the second output winding through the blocking diode to support continued operation of the converter in response to the input voltage dropping below the first threshold, the converter output voltages being regulated by the duty ratio of the first and second control signals.