Super capacitor battery clone

• US 5,850,113 A
• Filed: 04/15/1997
• Issued: 12/15/1998
• Est. Priority Date: 04/15/1997
• Status: Expired due to Fees

• Current Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Original Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Inventors: Cravens, Robert C. II, Weimer, Joseph A., Kazimierczuk, Marian K.
• Primary Examiner(s): Gaffin, Jeffrey
• Assistant Examiner(s): KAPLAN, JONATHAN STUART
• Application Number:
  US08/843,408
• Time in Patent Office: 609 Days
• Field of Search: 307/43, 307/44, 307/45, 307/46, 307/64, 307/65, 307/66, 307/70, 307/80, 307/82, 307/84, 307/85, 307/86, 307/87, 307/18, 307/23, 323/222, 323/223, 323/224, 323/282-285
• US Class Current: 307/125
• CPC Class Codes: F01D 15/10 Adaptations for driving, or combinations with, electric generators
• CPC Class Codes: F02C 7/32 Arrangement, mounting, or driving, of auxiliaries
• CPC Class Codes: H02J 1/06 Two-wire systems
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 9/061 for DC powered loads
• CPC Class Codes: H02M 3/1582 Buck-boost converters H02M3/1584 takes precedence
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

An aircraft electrical supply bus supplementing arrangement in which electrical energy is stored in a large capacitor and energy flow between the capacitor and the bus is controlled by a bi-directional electrical converter circuit of the switched inductance type. The varying terminal voltage of the energy storing capacitor, a super capacitor, is coupled to the relatively fixed voltage of the aircraft supply bus by way of the voltage changing capability of the converter circuit switched inductance. Current flow levels in this inductance are controlled with a negative feedback regulator circuit. Energy storage efficiency in the converter is enhanced with respect to weight and physical size of the capacitor element by ability of the converter circuit to accept a widely varying input voltage while generating a relatively constant output voltage. Suppression of electrical transients and improved regulation of voltage on the aircraft energy supply bus especially at distal and bus impedance-isolated locations are achieved.

Claims

1. Direct current aircraft electrical energy distribution apparatus comprising the combination of:

a source of direct current electrical energy located in a first portion of said aircraft;

an electrical bus having electrical bus conductors, including an electrically insulated conductor, connected with said source of direct current electrical energy, extending throughout said aircraft, including remote second portions of said aircraft, and connected in energizing relationship with a plurality of electrical transient generating aircraft electrical load devices also disposed throughout said aircraft;

a plurality of electrical energy storage devices located at selected distributed locations disposed throughout said aircraft and connected locally to said electrical bus conductors at selected distributed bus locations, said electrical energy storage devices including a capacitor element and an energy coupling electronic converter circuit of bi-directional energy flow capability communicating transient flows of electrical energy from said electrical bus conductors to said capacitor and from said capacitor to said electrical bus conductors in response to selected bus operating conditions;

said energy coupling electronic converter circuit comprising an electrical inductance element connected with said capacitor element and in series with said flows of electrical energy to and from said capacitor, a series connected first electrical switching element connected with said electrical inductance element and generating first electrical current undulations in said inductance element during first direction energy flows therein, a shunt-connected second electrical switching element also connected with said electrical inductance element and generating second electrical current undulations in said inductance element during second direction energy flows therein, and an electrical voltage regulator controller of pulse width time parameters of said electrical inductance element first and second electrical current undulations;

said electrical voltage regulator controller being pulse width time parameters-responsive to voltage levels appearing on said aircraft electrical bus adjacent each said electrical energy storage device;

said electrical voltage regulator controller including a trapezoidal waveshape regulation-determining pulsed voltage reference signal having a sloped leading edge and a flat constant voltage trailing portion of amplitude equal to a nominal operating voltage level of said aircraft electrical bus.

2. The direct current aircraft electrical energy distribution apparatus of claim 1 wherein said plurality of electrical energy storage devices located at selected distributed locations include capacitive electrical energy storage elements disposed in physical proximity with electronic apparatus loads having large transient energy current flow characteristics.

3. The direct current aircraft electrical energy distribution apparatus of claim 1 wherein said plurality of electrical energy storage devices located at selected distributed locations disposed throughout said aircraft include capacitive electrical energy storage elements located within electronic systems enclosures in physical proximity with electrical transient-generating bus-loading electronic apparatus.

4. The direct current aircraft electrical energy distribution apparatus of claim 1 wherein said electrical energy storage devices first and second electrical switching elements comprise one of a transistor and another semiconductor switching device.

5. The direct current aircraft electrical energy distribution apparatus of claim 1 wherein said electrical voltage regulator controller is a closed loop negative feedback voltage regulator having two of said trapezoidal waveshape Pulsed voltage reference signals, one controlling a capacitor charging operating mode and one controlling a capacitor discharging operating mode.

6. The direct current aircraft electrical energy distribution apparatus of claim 1 wherein said electrical voltage regulator controller includes periodic waveform generating electrical circuit means for generating said trapezoidal waveshape pulsed voltage reference signal and electrical circuitry selecting pulse width time parameters of said trapezoidal waveform generated by said periodic waveform generating electrical circuit means.

7. The direct current aircraft electrical energy distribution apparatus of claim 1 wherein said electrical voltage regulator controller includes an electrical inductance element connected in electrical series with said transient flows of electrical energy, one node of said electrical inductance element connecting with said super capacitor, and another node of said electrical inductance element connecting with said series-connected first electrical switching element and said shunt-connected second switching element.

8. The direct current aircraft electrical energy distribution apparatus of claim 1 further including electrical diode elements connected in reverse current direction shunt with said first electrical switching element and said second electrical switching element.

9. The direct current aircraft electrical energy distribution apparatus of claim 1 wherein, said electrical bus comprises a single electrically insulated conductor and an aircraft frame inclusive common return conductor.

10. The direct current aircraft electrical energy distribution apparatus of claim 1 wherein said aircraft electrical load devices include both rotating electrical machine and electronic circuit loads.

11. The direct current aircraft electrical energy distribution apparatus of claim 1 wherein said source of direct current electrical energy located in a first portion of said aircraft comprises a multiple phased alternator and a multiple diode rectifier array having a direct current output potential in excess of one hundred volts and said alternator comprises a portion of a propulsion engine apparatus located in one of a fuselage cavity and an exterior surface of said aircraft.

12. The direct current aircraft electrical energy distribution apparatus of claim 1 wherein said energy coupling electronic circuit includes first and second current direction controlling voltage responsive electrical circuitry connected to one of said aircraft electrical bus and said super capacitor element.

13. The method of supplying direct current electrical energy of limited transient noise content to electrical loads located at physically separate points along an aircraft energy supply bus, said method comprising the steps of:

supplementing electrical energy supplied via said aircraft energy supply bus to one of an electrical transient-generating load and an electrical transient sensitive load with electrical energy previously removed from said bus at a controlled removal rate and held in storage adjacent said load;

storing said previously removed electrical energy in an electrical capacitance storage element located adjacent said load;

operating said electrical capacitance storage element over a change of voltage range characteristic of removing and replacing at least one half the energy stored in said electrical capacitance storage element, a range exceeding electrical voltage transient amplitudes acceptable on said aircraft energy supply bus;

coupling energy from said electrical capacitance storage element to said energy supply bus of lesser voltage transient range via an electronic switching circuit-modulated electrical inductive element of variable coupling ratio, an element also located adjacent said load;

controlling said electrical capacitance storage element to aircraft energy supply bus variable coupling ratio according to an aircraft energy supply bus transient-responsive closed loop control algorithm;

controlling said flow of electrical energy previously removed from said bus and supplied to said electrical capacitance storage element according to a voltage-responsive control algorithm.

14. The method of supplying direct current electrical energy of claim 13 wherein said aircraft energy supply bus transient-responsive closed loop control algorithm is responsive to a decreased voltage level received from said electrical bus.

15. The method of supplying direct current electrical energy of claim 14 wherein said electronic switching circuit-modulated electrical inductive element of variable coupling ratio is a pulse width modulation-controlled variable coupling ratio.

16. The method of supplying direct current electrical energy of claim 13 wherein said step of coupling energy from said electrical capacitance storage element to said energy supply bus of lesser voltage transient range via an electronic switching circuit-modulated electrical inductive element of variable coupling ratio further includes the step of disconnecting said inductive element from said aircraft energy supply bus during operating cycle portions of said electronic switching circuit modulation.

17. The method of supplying direct current electrical energy of claim 13 wherein said step of supplementing electrical energy supplied via said aircraft energy supply bus to an electrical transient-generating load with electrical energy previously removed from said bus at a controlled removal rate includes supplying electrical energy to said electrical capacitance storage element from said bus and delivering electrical energy from said electrical capacitance storage element to said bus through a common bi-directional current flow-capable direct current to direct current converter circuit.

18. Direct current aircraft electrical energy distribution apparatus comprising the combination of:

a source of direct current electrical energy located in a first portion of said aircraft;

an electrical bus having electrical bus conductors, including an electrically insulated conductor, connected with said source of direct current electrical energy, extending throughout said aircraft, including remote second portions of said aircraft, and connected in energizing relationship with a plurality of electrical transient generating electromagnetic, and electrical transient-sensitive electronic, aircraft electrical load devices also disposed throughout said aircraft;

a plurality of electrical energy storage devices located at selected distributed locations disposed throughout said aircraft and connected locally to said electrical bus conductors at selected distributed bus locations, said electrical energy storage devices including an electrolytic super capacitor element and an energy coupling electronic converter circuit of bi-directional energy flow capability communicating transient flows of electrical energy from said electrical bus conductors to said super capacitor and from said super capacitor to said electrical bus conductors in response to selected bus voltage operating conditions and selected super capacitor voltage operating conditions;

said energy coupling electronic converter circuit comprising;

an electrical inductance element connected with said super capacitor and in series with said flows of electrical energy to and from said super capacitor,

series connected first electrical switching means connected between said electrical inductance element and said aircraft electrical bus for generating first electrical current undulations in said inductance element during aircraft bus to super capacitor energy flow events,

shunt connected second electrical switching means connected across a series combination of said super capacitor element and said electrical inductance element for generating second electrical current undulations in said inductance element during super capacitor to aircraft electrical bus energy flow events,

first electrical voltage regulating controller means responsive to a voltage level of said aircraft bus for controlling duty cycle ON and OFF times of said series connected first electrical switching means,

second electrical voltage regulating controller means responsive to a voltage level of said super capacitor for controlling duty cycle ON and OFF times of said second electrical switching means,

said first electrical voltage regulating controller means and said second electrical voltage regulating controller means each including sloped leading edge waveform signal source means for generating varied duty cycle ON and OFF times of said first and second electrical switching means in response to a regulated signal sensed variation.

19. The direct current aircraft electrical energy distribution apparatus of claim 18 wherein:

said source of direct current electrical energy includes one of an engine driven electrical generator and an engine driven electrical alternator plus rectifier array connected to a selected point on said electrical bus;

said source of direct current electrical energy also includes an electrochemical battery element connected to a selected point on said electrical bus;

said plurality of electrical energy storage devices include one of said electrical energy storage devices connected to said electrical bus at a physical location adjacent one of said electrical transient-sensitive aircraft electronic aircraft load devices;

at least one of said first electrical voltage regulating controller means and said second electrical voltage regulating controller means include means for terminating operation of said electronic converter circuit in response to a sensed low voltage condition.