Li I Chen

US Patent:

6366049, Apr 2, 2002

Filed:

May 10, 2000

Appl. No.:

09/567592

Inventors:

Li Chen - Livonia MI
Richard Joseph Hampo - Livonia MI
Yifan Zhao - Bellevile MI

Assignee:

Ecostar Electric Drive Systems L.L.C. - Dearborn MI

International Classification:

H02P 528

US Classification:

318799, 318432, 318433, 318434, 318727, 318609, 318610, 318800, 318801

Abstract:

A speed controller circuit for a motor including a ramp function generator having a first input connected to a source of a speed demand signal and a second input connected to a ramp step signal. The ramp function generator develops a frequency ramp that has a slope is initiated by the speed demand signal which is adjusted in response to the ramp step signal. The ramp function generator also provides a frequency signal wherein the ramp function increases or decreases the frequency according to the speed demand. A V/F circuit to the ramp function generator and a space vector modulation circuit are connected to the V/F circuit. The output of the space vector modulation circuit is applied through power switching devices to the motor for speed control. A PI controller circuit is connected to a motor current feedback signal and to a maximum current signal, which provides the current limit of the control system. The output signal from the PI controller circuit is a ramp step signal used to adjust the ramp signal of the ramp function generator to provide to provide the best performance of the motor control system and achieve a better starting time for the motor.

US Patent:

6377019, Apr 23, 2002

Filed:

Feb 10, 2000

Appl. No.:

09/499366

Inventors:

Li Chen - Livonia MI

Assignee:

Ford Global Technologies, Inc. - Dearborn MI

International Classification:

H02P 7628

US Classification:

318807, 318803, 318805, 318808, 318809, 318798

Abstract:

An induction motor control system ( ) for electric vehicles having a DC power supply ( ), an inverter ( ), an induction motor ( ), a motor controller ( ) and a vehicle-level controller ( ). The method and system of the present invention optimizes the torque output for the induction motor and utilizes minimum power. The method and system of the present invention calculates the flux current such that the slip frequency is maintained at a nominal level, thereby producing peak torque.

US Patent:

6388419, May 14, 2002

Filed:

Sep 1, 2000

Appl. No.:

09/653654

Inventors:

Li Chen - Livonia MI
Xingyi Xu - Canton MI
Richard Joseph Hampo - Livonia MI
Kerry Eden Grand - Chesterfield MI

Assignee:

Ford Global technologies, Inc. - Dearborn MI

International Classification:

H02P 124

US Classification:

318727, 318138, 318254, 318800, 318801, 318802, 318803, 318804, 318805, 318806, 318807, 318808

Abstract:

A motor control system for use within an electric vehicle having an induction motor Control system utilizes a torque control module a vector control module and a space vector PWM module to efficiently and accurately control the torque provided by motor.

US Patent:

6593463, Jul 15, 2003

Filed:

Oct 20, 1998

Appl. No.:

09/175684

Inventors:

Li How Chen - Acton MA
Harry Meade - Newton MA

Assignee:

Genzyme Transgenics Corporation - Framingham MA

International Classification:

C07H 2104

US Classification:

536 237, 435 691, 435 693, 4353201, 424 932, 4241851, 4242681, 4242721, 530300, 530350

Abstract:

The invention provides modified recombinant nucleic acid sequences (preferably DNA) and methods for increasing the mRNA levels and protein expression of malarial surface protein MSP-1 which is known to be difficult to express in cell culture systems, mammalian cell culture systems, or in transgenic animals. The preferred protein candidates for expression using the recombinant techniques of the invention are MSP-1 proteins expressed from DNA coding sequences comprising reduced overall AT content or AT rich regions and/or mRNA instability motifs and/or rare codons relative to the native MSP-1 gene.

US Patent:

6630809, Oct 7, 2003

Filed:

Nov 29, 2001

Appl. No.:

09/683180

Inventors:

Li Chen - Livonia MI
Xingyi Xu - Canton MI
Vinod Reddy - Ocala FL
Richard Joseph Hampo - Plymouth MI
Kerry Eden Grand - Chesterfield MI

Assignee:

Ballard Power Systems Corporation - Dearborn MI

International Classification:

H02P 764

US Classification:

318804, 318800, 318801

Abstract:

Field oriented induction motor system including a field oriented induction motor having an associated torque current and an associated flux current and a predetermined current ratio, wherein the predetermined current ratio is defined as the ratio of the torque current to the flux current, and wherein the predetermined current ratio is dependent upon the saturation state of the motor. A method for selecting the ratio of torque current to flux current for a field oriented induction motor including applying an allocation factor to the torque current and flux current, wherein the allocation factor is dependent upon the saturation state of the motor. The saturation state of the motor is determined based upon motor parameters.

US Patent:

6707270, Mar 16, 2004

Filed:

Nov 13, 2001

Appl. No.:

10/010307

Inventors:

Li Chen - Livonia MI
Kerry Eden Grand - Chesterfield MI
Richard Joseph Hampo - Plymouth MI
Vinod Reddy - Ocala FL
Xingyi Xu - Canton MI
Nick Langovsky - Inkster MI

Assignee:

Ballard Power Systems Corporation - Dearborn MI

International Classification:

H02P 736

US Classification:

318798, 318806, 318808

Abstract:

System and method for enhancing the torque output of a field oriented induction motor including a controller having a plurality of predetermined control parameters operable for processing input signals to generate output signals. The plurality of predetermined control parameters are dependent upon the nature of the input signals and the operational state of the motor. A sensor system is operable for communicating feedback signals related to the output signals and the operational state of the motor from the motor to the controller.

US Patent:

6815925, Nov 9, 2004

Filed:

Nov 12, 2002

Appl. No.:

10/293911

Inventors:

Li Chen - Livonia MI
Xingyi Xu - Canton MI
Vinod Reddy - Ocala FL
Richard J. Hampo - Plymouth MI
Kerry E. Grand - Chesterfield MI

Assignee:

Ballard Power Systems Corporation - Dearborn MI

International Classification:

H02P 124

US Classification:

318727, 318767, 318772, 318798, 318804, 318801

Abstract:

Systems and methods for controlling and/or calculating the torque for a field oriented induction motor operating at a given stator frequency. The systems and methods include calculating the torque using a first algorithm when the motor is at or below a first predetermined stator frequency, a second algorithm when the motor is at or above a second predetermined stator frequency, and a third algorithm when the motor is between the first predetermined stator frequency and the second predetermined stator frequency.

US Patent:

6844701, Jan 18, 2005

Filed:

Jan 15, 2003

Appl. No.:

10/345872

Inventors:

Li Chen - Livonia MI, US
Richard J. Hampo - Plymouth MI, US
Venkatapathi R. Nallapa - West Bloomfield MI, US

Assignee:

Ballard Power Systems Corporation - Dearborn MI

International Classification:

H02P 736
H02P 528
H02P 318
H02P 700

US Classification:

318825, 318822, 318806, 318432

Abstract:

Systems and methods for controlling an induction motor including detecting a field weakening operation state of the motor, wherein the field weakening operation state is detected when a flux current, I, in the motor is reduced to a predetermined fraction of its normal, non-voltage limited value. The systems and methods also including an overmodulation operation state of the motor before said field weakening operation state is detected and enabling the overmodulation operation state of the motor after said field weakening operation state is detected.