Hybrid power system

• US 5,031,086 A
• Filed: 12/20/1989
• Issued: 07/09/1991
• Est. Priority Date: 12/20/1989
• Status: Expired due to Fees

• Current Assignee: Sundstrand Corporation (Rtx Corporation)
• Original Assignee: Sundstrand Corporation (Rtx Corporation)
• Inventors: Patel, Sunil, Ng, Chai-Nam, Dhyanchand, P. John, Nguyen, Vietson
• Primary Examiner(s): Wong, Peter S.
• Application Number:
  US07/454,009
• Time in Patent Office: 566 Days
• Field of Search: 363/37, 363/41, 363/43, 363/64, 363/65, 363/71, 363/72, 363/95, 363/97, 363/98, 363/131, 363/132, 322/25, 322/28, 322/89, 322/90
• US Class Current: 363/37
• CPC Class Codes: H02M 7/49 Combination of the output voltage waveforms of a plurality of converters

Abstract

A hybrid power system which converts variable-frequency power developed by a brushless generator into DC power which is supplied to a DC load and constant-frequency AC power which is supplied to an AC load includes an AC/DC converter coupled to a main generator portion armature winding of the generator which converts the variable-frequency power produced by the generator into the DC power and a DC/AC converter coupled to the AC/DC converter which converts the DC power into the constant-frequency AC power. A first regulator is coupled to an exciter portion field winding of the generator for supplying current thereto in dependence upon a parameter of the DC power to maintain such parameter substantially at a regulated DC value. A second regulator is coupled to the DC/AC converter for controlling same in accordance with a parameter of the constant-frequency AC power to maintain such parameter substantially at a regulated AC value.

Claims

1. A hybrid power system which converts variable-frequency power developed by a brushless generator into DC power which is supplied to a DC load and constant-frequency AC power which is supplied to an AC load wherein the generator includes an exciter portion and a main generator portion each having field and armature windings, the exciter portion armature winding being coupled to the main generator portion field winding and the variable-frequency AC power being developed in the main generator portion armature windings, comprising:

an AC/DC converter coupled to the main generator portion armature winding for converting the variable-frequency power into the DC power;

a stepped-waveform inverter coupled to the AC/DC converter for converting the DC power into the constant-frequency AC power including first through sixth three-phase subinverters that produce first through sixth waveforms, respectively, a summing transformer having first through sixth sets of primary windings coupled to the sixth subinverters, respectively, and a set of three-phase secondary windings in which three-phase voltages are produced wherein the third and fourth waveforms are displaced a fixed angle α

₁ relative to the first and second waveforms, respectively, and the fifth and sixth waveforms are displaced a variable angle α

₂ relative to the third and fourth waveforms, respectively;

means coupled to the exciter portion field winding for supplying current thereto in dependence upon a parameter of the DC power to maintain such parameter substantially at a regulated DC value; and

means coupled to the stepped-waveform inverter for controlling the angle α

₂ in accordance with a parameter of the constant-frequency AC power to maintain such parameter substantially at a regulated AC value.

2. The hybrid power system of claim 1, wherein the AD/DC converter comprises a plurality of uncontrolled rectifiers coupled together in a bridge configuration.

3. A hybrid power system which converts variable-frequency power developed by a three-phase brushless generator into DC power and three-phase constant-frequency AC power wherein the generator includes an exciter portion and a main generator portion, the exciter portion having a field winding and a armature winding, the main generator portion having a field winding coupled to the exciter and a set of three-phase armature windings in which the variable-frequency power is produced, comprising:

a plurality of diodes connected together to form a bridge having three inputs coupled to the set of three-phase armature windings and a pair of outputs at which the DC power is produced;

a stepped-waveform inverter having a pair of inputs coupled to the pair of outputs of the bridge, first through sixth subinverters each having controllable switches coupled to the pair of inputs and developing first through sixth waveforms, respectively, a summing transformer having first through sixth sets of primary windings coupled to the first through sixth subinverters, respectively, and a set of three-phase secondary windings in which the constant-frequency power is produced, the first, third and fifth sets of primary windings being connected in a wye configuration and the second, fourth and sixth sets of primary windings being connected in a delta configuration wherein the third and fourth waveforms are displaced a fixed angle α

₁ relative to the first and second waveforms, respectively, and the fifth and sixth waveforms are displaced a variable angle α

₂ relative to the third and fourth waveforms, respectively;

a first regulator coupled between the bridge and the exciter portion field winding which delivers a controlled current to the exciter portion field winding in dependence upon a parameter of the DC power; and

a second regulator coupled to the inverter which operates the first through sixth subinverters to control the angle α

₂ in dependence upon a parameter of the constant-frequency AC power.