Edward E Cornell

US Patent:

40399141, Aug 2, 1977

Filed:

Nov 25, 1975

Appl. No.:

5/635143

Inventors:

Robert L. Steigerwald - Scotia NY
Edward P. Cornell - Schenectady NY

Assignee:

General Electric Company - Schenectady NY

International Classification:

H02P 312

US Classification:

318375

Abstract:

A current source power converter for an electric motor is comprised by a combined controlled rectifier and chopper which is coupled to a controlled-current inverter by a dc reactor. In the motoring mode the combined rectifier and chopper functions as a phase controlled rectifier to control the current magnitude. In the dynamic braking mode a line switch is opened and a braking resistor placed across the rectifier output, and the combined rectifier and chopper is operated as a chopper to control the average voltage across the braking resistor and thus the current magnitude during braking.

US Patent:

40413616, Aug 9, 1977

Filed:

Oct 14, 1975

Appl. No.:

5/621951

Inventors:

Edward P. Cornell - Schenectady NY

Assignee:

General Electric Company - Schenectady NY

International Classification:

H02K 1702

US Classification:

318227

Abstract:

An ac induction motor is supplied with variable frequency and amplitude excitation voltage by a power converter. Precise regulation of torque independent of motor parameter changes is achieved by feedback control loops for maintaining at command values constant airgap flux and also the real component of stator current with respect to airgap voltage as measured by a voltage sensor. The real stator current error controls the slip frequency which adjusts to maintain constant airgap power.

US Patent:

40191052, Apr 19, 1977

Filed:

Sep 26, 1975

Appl. No.:

5/617187

Inventors:

Edward P. Cornell - Schenectady NY
Thomas A. Lipo - Schenectady NY

Assignee:

General Electric Company - Schenectady NY

International Classification:

H02R 540

US Classification:

318227

Abstract:

Improved stable four-quadrant operation of an induction motor supplied with variable amplitude and frequency stator line current by a motor controller with a constant current source converter is achieved by using several feedback control loops to control the slip frequency as well as the stator line current amplitude and frequency. Speed feedback is employed with optional control of rotor speed. Motor performance is optimized by indirectly regulating air gap flux to its rated value by controlling slip frequency as a function of sensed stator current. Thus, torque is approximately linear with stator current.