Stephen R Macminn

US Patent:

48960896, Jan 23, 1990

Filed:

Jan 31, 1989

Appl. No.:

7/304159

Inventors:

Gerald B. Kliman - Schenectady NY
Stephen R. MacMinn - Schenectady NY
Charles M. Stephens - Pattersonville NY

Assignee:

General Electric Company - Schenectady NY

International Classification:

H02P 800

US Classification:

318701

Abstract:

A fault management system for a switched reluctance motor detects faults through phase current differential sensing and phase flux differential sensing and isolates any fault by deactivating any faulted phase. Motor operation continues through the remaining phases. A speed control circuit maintains the normal operating speed of the motor, despite the deactivation of one or more phases. Starting the motor when stopped in a "dead zone" created by a faulted phase is accomplished by using the intact phases to generate negative torque to move the rotor out of the dead zone.

US Patent:

51071959, Apr 21, 1992

Filed:

Feb 11, 1991

Appl. No.:

7/653371

Inventors:

James P. Lyons - Niskayuna NY
Stephen R. MacMinn - Schenectady NY
Mark A. Preston - Niskayuna NY

Assignee:

General Electric Company - Schenectady NY

International Classification:

H02F 800

US Classification:

318701

Abstract:

A method and apparatus for indirectly determining rotor position in a switched reluctance motor (SRM) are based on a flux/current model of the machine, which model includes multi-phase saturation, leakage, and mutual coupling effects. The flux/current model includes a network mesh of stator, rotor and air gap reluctance terms. The network is driven by magnetomotive force (mmf) terms corresponding to the ampereturns applied to each of the stator poles. Phase current and flux sensing for each phase are performed simultaneously. The reluctance terms of the flux/current model are determined from the phase flux and current measurements. The phase current and flux measurements also determine the rotor position angle relative to alignment for each respective motor phase and which phase (or phases) is operating in its predetermined optimal sensing region defined over a range of rotor angles. The measurements on at least two phases are then used for establishing whether the stator phases of the sensing phase are approaching alignment or maximum unalignment with SRM rotor poles. Finally, the rotor position angle for the sensing phase and its position relative to alignment are used to provide a rotor position estimate for the motor.

US Patent:

49336215, Jun 12, 1990

Filed:

May 12, 1989

Appl. No.:

7/350884

Inventors:

Stephen R. MacMinn - Schenectady NY
Fred G. Turnbull - Scotia NY

Assignee:

General Electric Company - Schenectady NY

International Classification:

H02P 800

US Classification:

318696

Abstract:

A method and apparatus are provided for controlling the switching devices in a switched reluctance machine bridge inverter having at least two switching devices per phase. One switching device is used for hysteresis band current chopping to regulate phase current magnitude, while the other switching device, in combination with a flyback diode, provides a circulating path for phase current. Alternatively, current chopping and circulating are alternated between both switching devices during each conduction interval of the corresponding machine phase. Ripple current is decreased, thereby reducing the required size of the DC link capacitor. Switching losses are also reduced.

US Patent:

49610384, Oct 2, 1990

Filed:

Oct 16, 1989

Appl. No.:

7/421885

Inventors:

Stephen R. MacMinn - Schenectady NY

Assignee:

General Electric Company - Schenectady NY

International Classification:

H02P 800

US Classification:

318696

Abstract:

Apparatus for estimating torque generated by a switched reluctance machine utilizes a ROM table look-up scheme to generate a torque estimate based upon phase current and rotor position information. Each ROM address is accessed by digitizing and then combining sensed phase current and rotor position signals. Knowledge of the instantaneous torque output enables closed-loop torque control including appropriate adjustments of phase currents to reduce or eliminate torque pulsations.

US Patent:

49595962, Sep 25, 1990

Filed:

Apr 3, 1989

Appl. No.:

7/332205

Inventors:

Stephen R. MacMinn - Schenectady NY
Charles M. Stephens - Pattersonville NY
Paul M. Szczesny - Burnt Hills NY

Assignee:

General Electric Company - Schenectady NY

International Classification:

H02P 800

US Classification:

318254

Abstract:

A microcomputer-based drive system for a switched reluctance motor requires no rotor position sensor and no discrete current sensors. Phase excitation is synchronized with rotor position by indirectly estimating rotor position according to instantaneous phase inductance. Current regulation is achieved by incorporating pilot devices for current sensing into the switching devices of the power converter and by employing a fixed off-time current chopping strategy. One application is for use in a laundering machine.

US Patent:

51402432, Aug 18, 1992

Filed:

Sep 13, 1991

Appl. No.:

7/760039

Inventors:

James P. Lyons - Niskayuna NY
Stephen R. MacMinn - Schenectady NY
Mark A. Preston - Niskayuna NY

Assignee:

General Electric Company - Schenectady NY

International Classification:

H02P 800

US Classification:

318701

Abstract:

A rotor position estimator for a switched reluctance motor (SRM) employs a flux-current map to determine whether the actual rotor angle is closer to, or farther from, axial alignment of stator and rotor poles than a reference angle. theta. sub. r. The flux-current map is a plot of reference flux. PSI. sub. r as a function of current for the reference angle. theta. sub. r. If a flux linkage estimate. PSI. sub. i is greater than the reference flux. PSI. sub. r, then the actual rotor angle is closer to alignment than the reference angle. theta. sub. r, and the flux-map comparator output is a logic level one. If the flux linkage estimate. PSI. sub. i is lower than the reference flux. PSI. sub. r, then the actual rotor angle is farther from alignment than the reference angle. theta. sub. r, and the flux-map comparator output is a logic level zero.

US Patent:

47392401, Apr 19, 1988

Filed:

Apr 29, 1987

Appl. No.:

7/044075

Inventors:

Stephen R. MacMinn - Schenectady NY
Paul M. Szczesny - Burnt Hills NY

Assignee:

General Electric Company - Schenectady NY

International Classification:

H02P 800

US Classification:

318696

Abstract:

A commutator for a microcomputer based switched reluctance drive employs a selectively addressable non-volatile memory, e. g. a ROM, to store stator phase firing patterns and facilities selective adjustment of turn-on angle and pulsewidth of phase switching current pulses. Firing patterns differing only in pulsewidth of their respective pulses can be stored in different sections of the memory or in the same section where word bit width permits. The adjustment of pulse position and duration allows torque control of the motor over a very wide speed range.

US Patent:

50971905, Mar 17, 1992

Filed:

Feb 11, 1991

Appl. No.:

7/653374

Inventors:

James P. Lyons - Niskayuna NY
Stephen R. MacMinn - Schenectady NY

Assignee:

General Electric Company - Schenectady NY

International Classification:

H02P 800

US Classification:

318701

Abstract:

A method and apparatus for indirectly determining rotor position in a switched reluctance motor (SRM) are based on instantaneous flux and phase current sensing. For each phase in a predetermined sequence of phase sensing, which depends on the particular quadrant of machine operation, phase flux and phase current measurements are made during operation in a pair of predetermined sensing regions each defined over a range of rotor angles. Rotor angle estimates are derived from the flux and phase current measurements made during the sensing region for each respective phase. The rotor angle estimates for each phase are normalized with respect to a common reference and then used to generate a rotor position estimate for the SRM.