Alternator boost method

• US 7,514,807 B2
• Filed: 04/25/2006
• Issued: 04/07/2009
• Est. Priority Date: 04/25/2005
• Status: Expired due to Fees

• Current Assignee: Railpower, LLC
• Original Assignee: Railpower Technologies Corp.
• Inventors: Donnelly, Frank, Tarnow, Andrew
• Primary Examiner(s): Waks; Joseph
• Application Number:
  US11/411,987
• Publication Number:
  US 20060266044A1
• Time in Patent Office: 1,078 Days
• Field of Search: 280/40.C
• US Class Current: 290/40.00C
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 2220/12 Induction machines
• CPC Class Codes: B60L 2220/14 Synchronous machines
• CPC Class Codes: B60L 2220/18 Reluctance machines
• CPC Class Codes: B60L 2260/165 of converters
• CPC Class Codes: B60L 2260/167 of motors or generators
• CPC Class Codes: B60L 50/15 with additional electric power supply with capacitors charged by engine-driven generators B60L50/40; with batteries charged by engine-driven generators B60L50/61
• CPC Class Codes: B60L 50/30 using propulsion power stored mechanically, e.g. in fly-wheels
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60L 7/06 for vehicles propelled by ac motors
• CPC Class Codes: B60L 7/14 for vehicles propelled by ac motors
• CPC Class Codes: B60L 7/22 Dynamic electric resistor braking, combined with dynamic electric regenerative braking
• CPC Class Codes: B60L 9/00 Electric propulsion with power supply external to the vehicle electric propulsion for monorail vehicles, suspension vehicles or rack railways B60L13/00; in combination with batteries or fuel cells within the vehicle B60L50/53
• CPC Class Codes: B60L 9/16 using ac induction motors
• CPC Class Codes: B61C 7/04 Locomotives or motor railcars with two or more different kinds or types of engines, e.g. steam and IC engines
• CPC Class Codes: F02D 25/04 by cutting-out engines
• CPC Class Codes: F02D 29/06 peculiar to engines driving electric generators
• CPC Class Codes: F02N 11/04 the motors being associated with current generators
• CPC Class Codes: F02N 2011/0888 DC/DC converters
• CPC Class Codes: F02N 7/10 : characterised by using auxiliary engines or apparatus of combustion type by using explosive cartridges F02N13/00
• CPC Class Codes: H02M 3/1552 : Boost converters exploiting the leakage inductance of a transformer or of an alternator as boost inductor
• CPC Class Codes: H02P 2201/09 : Boost converter, i.e. DC-DC step up converter increasing the voltage between the supply and the inverter driving the motor general aspects of plural converters in cascade H02M
• CPC Class Codes: H02P 25/16 : characterised by the circuit arrangement or by the kind of wiring
• CPC Class Codes: H02P 9/305 : controlling voltage H02P9/302 takes precedence
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 30/00 : Transportation of goods or passengers via railways, e.g. energy recovery or reducing air resistance

Abstract

A circuit for boosting the voltage output of an alternator utilizes the armature coils of the alternator as part of the boost circuit. The circuit and methods utilizing this circuit can enable refined control strategies for operating a plurality of engine systems during propulsion, idling and braking and is applicable to large systems such as trucks, ships, cranes and locomotives utilizing diesel engines, gas turbine engines, other types of internal combustion engines, fuel cells or combinations of these that require substantial power and low emissions utilizing multiple power plant combinations.

Claims

1. A propulsion system, comprising:

(a) an engine system comprising;

an engine; and

an n-phase alternator operable to convert mechanical energy output by the engine into alternating current electrical energy, each phase corresponding to an armature winding;

(b) at least one traction motor in electrical communication with the alternator;

(c) a plurality of pairs of first and second rectifier diodes to convert the outputted alternating current electrical energy into direct current electrical energy, each of said plurality of pairs of rectifier diodes being connected to a respective n-armature winding of the alternator, each of said first and second rectifier diodes having an input and an output, the output of the first rectifier diode being connected to the input of the second rectifier diode and to the respective n-armature winding of the alternator; and

(d) a voltage boost circuit electrically connected with each of the n-armature windings of the alternator to boost an output voltage associated with each armature winding, wherein each armature winding provides an inductance for the voltage boost circuit, the voltage boost circuit comprising;

a single switch having an input and an output, the output of the switch being connected to the inputs of the plurality of first rectifier diodes;

a plurality of power diodes connected in parallel to the switch, each of said plurality of power diodes having an input and an output, the input of each of said plurality of power diodes being connected to a respective output of the first rectifier diode of the plurality of pairs of rectifier diodes, the output of each of said plurality of power diodes being connected in parallel to input of the switch; and

a capacitor connected in parallel to the plurality of pairs of first and second rectifier diodes.

2. The propulsion system of claim 1, wherein the single switch is an IGBT switch and further comprising:

a control system operable, based on a measured mechanical or electrical parameter of the alternator, to control a switching rate of the IGBT switch such that the IGBT switch, the capacitor, and the diodes form a variable voltage boost circuit with each of the n-armature windings of the alternator during the corresponding power phase of the nth armature winding, whereby the output voltage of the engine system can be varied independently of engine speed.

3. The system of claim 1, wherein the switch, in a first mode, is conducting and, in a second mode, is nonconducting and rectifies the electrical energy.

4. The system of claim 1, wherein the voltage boost circuit does not boost the voltage when a revolutions-per-minute of the engine is greater than a first threshold and boosts the voltage when the revolutions-per-minute of the engine is less than the first threshold.

5. A propulsion method, comprising the steps of:

(a) providing a propulsion system, comprising;

(i) an engine system comprising;

an engine; and

an n-phase alternator operable to convert mechanical energy output by the engine into alternating current electrical energy, each phase corresponding to an armature winding;

(ii) at least one traction motor in electrical communication with the alternator;

(iii) a plurality of pairs of first and second rectifier diodes to convert the outputted alternating current electrical energy into direct current electrical energy, each of said plurality of pairs of rectifier diodes being connected to a respective n-armature winding of the alternator, each of said first and second rectifier diodes having an input and an output, the output of the first rectifier diode being connected to the input of the second rectifier diode and to the respective n-armature winding of the alternator; and

(iv) a voltage boost circuit electrically connected with each of the n-armature windings of the alternator to boost an output voltage associated with each armature winding, wherein each armature winding provides an inductance for the voltage boost circuit, the voltage boost circuit comprising;

a single switch having an input and an output, the output of the switch being connected to the inputs of the plurality of first rectifier diodes;

a plurality of power diodes connected in parallel to the switch, each of said plurality of power diodes having an input and an output, the input of each of said plurality of power diodes being connected to a respective output of the first rectifier diode of the plurality of pairs of rectifier diodes, the output of each of said plurality of power diodes being connected in parallel to input of the switch; and

a capacitor connected in parallel to the plurality of pairs of first and second rectifier diodes;

(b) in a first mode in which the switch is conducting, directing the outputted electrical current of the n-phase alternator along a first path through the power diodes, through the switch, and back to a selected one of the armature windings of the alternator, thereby storing electrical energy in the selected armature winding; and

(c) in a second mode in which the switch is nonconducting, directing the output electrical current along a second path through the rectifier diodes to a load, wherein the second path bypasses the switch.

6. The method of claim 5, wherein each armature winding is in the first mode at a different time, wherein a control system, based on a measured mechanical or electrical parameter of the alternator, controls the on-off duty cycle of the switch between the first and second modes such that the switch, the capacitor, and the power diodes form a variable voltage boost circuit with each of the n-armature windings of the alternator during the corresponding first mode of the nth armature winding, whereby the output voltage of the engine system can be varied independently of engine speed.

7. The method of claim 5, wherein in the first mode the current flows through the capacitor in a first direction and in the second mode the current flows through the capacitor in an opposing second direction.

8. In a multi-engine vehicle, a propulsion method, comprising the steps of:

(a) determining an operating voltage range for a direct current electrical bus;

(b) determining a power requirement to be provided to the direct current electrical bus by a plurality of engines;

(c) selecting at least a subset of the engines systems to provide the determined power requirement to the direct current electrical bus;

(d) determining a first magnitude of an operational parameter for each of the selected engine systems to provide, to the direct current electrical bus, the selected engine'"'"'s portion of the determined power requirement;

(e) setting each of the selected engine systems to the corresponding first magnitude of the determined operational parameter to provide the selected engine system'"'"'s portion of the determined power requirement to the direct current electrical bus;

(f) measuring an electrical parameter of each of the selected engine systems;

(g) comparing the measured electrical parameter of each of the selected engine systems to the corresponding portion of the determined power requirement; and

(h) if needed, adjusting at least one of (i) the first magnitude of the operational parameter of the selected engine system and (ii) the electrical parameter of the selected engine system to produce the corresponding required electrical power output for the selected engine system,

wherein at least one of the selected engine systems comprises;

(i) an n-phase alternator operable to convert mechanical energy output by the engine system into alternating current electrical energy, each phase corresponding to an armature winding;

(ii) at least one traction motor in electrical communication with the alternator;

(iii) a plurality of pairs of first and second rectifier diodes to convert the outputted alternating current electrical energy into direct current electrical energy, each of said plurality of pairs of rectifier diodes being connected to a respective n-armature winding of the alternator, each of said first and second rectifier diodes having an input and an output, the output of the first rectifier diode being connected to the input of the second rectifier diode and to the respective n-armature winding of the alternator; and

(iv) a voltage boost circuit electrically connected with each of the n-armature windings of the alternator to boost an output voltage associated with each armature winding, wherein each armature winding provides an inductance for the voltage boost circuit, the voltage boost circuit comprising;

a single switch having an input and an output, the output of the switch being connected to the inputs of the plurality of first rectifier diodes;

a plurality of power diodes connected in parallel to the switch, each of said plurality of power diodes having an input and an output, the input of each of said plurality of power diodes being connected to a respective output of the first rectifier diode of the plurality of pairs of rectifier diodes, the output of each of said plurality of power diodes being connected in parallel to input of the switch; and

a capacitor connected in parallel to the plurality of pairs of first and second rectifier diodes.

9. The method of claim 8, wherein in the setting step (e), the electrical parameter is set and wherein the electrical parameter is at least one of an output electrical voltage, an output electrical current and output electrical power.

10. A propulsion system, comprising:

(a) a plurality of prime power systems, each prime power system comprising;

a prime power source device; and

an energy conversion device operable to convert energy output by the prime power device into direct current electrical energy, wherein the prime power system is an engine and the energy conversion device is a mechanical-to-electrical energy conversion device operable to convert mechanical energy output by the engine into direct current electrical energy;

(b) a direct current bus connecting the plurality of prime power systems, the direct current bus being operable to carry the direct current electrical energy to and/or from the prime power systems;

(c) a voltage sensor for measuring a voltage level across the direct current bus;

(d) a plurality of current sensors, each current sensor measuring a direct current electrical energy outputted by a selected prime power system; and

(e) a control system operable, based on the measured voltage level across the direct current bus and the respective measured direct current electrical energy into and/or out of each prime power system, to control an electrical parameter of the selected prime power system, wherein the electrical parameter is at least one of an output electrical voltage, an output electrical current, and output electrical power; and

wherein the selected prime power system comprises;

(i) an n-phase alternator operable to convert mechanical energy output by the selected prime power system into alternating current electrical energy, each phase corresponding to an armature winding;

(ii) at least one traction motor in electrical communication with the alternator;

(iii) a plurality of pairs of first and second rectifier diodes to convert the outputted alternating current electrical energy into direct current electrical energy, each of said plurality of pairs of rectifier diodes being connected to a respective n-armature winding of the alternator, each of said first and second rectifier diodes having an input and an output, the output of the first rectifier diode being connected to the input of the second rectifier diode and to the respective n-armature winding of the alternator; and

(iv) a voltage boost circuit electrically connected with each of the n-armature windings of the alternator to boost an output voltage associated with each armature winding, wherein each armature winding provides an inductance for the voltage boost circuit, the voltage boost circuit comprising;

a single switch having an input and an output, the output of the switch being connected to the inputs of the plurality of first rectifier diodes;

a plurality of power diodes connected in parallel to the switch, each of said plurality of power diodes having an input and an output, the input of each of said plurality of power diodes being connected to a respective output of the first rectifier diode of the plurality of pairs of rectifier diodes, the output of each of said plurality of power diodes being connected in parallel to input of the switch; and

a capacitor connected in parallel to the plurality of pairs of first and second rectifier diodes.