Textiles: ironing or smoothing – Smoothing implements – Flatirons
Reexamination Certificate
2002-10-10
2004-07-20
Masih, Karen (Department: 2837)
Textiles: ironing or smoothing
Smoothing implements
Flatirons
C318S801000, C318S606000, C318S802000, C318S807000, C318S503000
Reexamination Certificate
active
06763622
ABSTRACT:
TECHNICAL FIELD
The present invention relates to the control of electric motors. More specifically, the present invention relates to a method and apparatus for position sensorless control of an electric motor.
BACKGROUND OF THE INVENTION
Traditional motor control systems normally include a feedback device or position sensor such as a resolver or encoder to provide speed and position information for a motor. Feedback devices and associated interface circuits increase the costs of a motor control system, and these costs may become prohibitive in high volume applications such as automotive applications. Additionally, a position sensor and its associated wiring harness increase the complexity and assembly time of an electric drive system in a vehicle.
Electric vehicles powered by fuel cells, batteries and hybrid systems that include electric motors are becoming more common in the automotive market. As production volumes for electric vehicles increase, the cost of feedback devices and associated interface circuits will become significant. Automakers are under intense market pressure to cut costs and reduce the number of parts for a vehicle. The removal of a feedback device for an electric motor control system will lead to significant cost reductions for an electric vehicle.
Hybrid electric and electric vehicles today utilize numerous electric motor control technologies such as the vector control of electric motors. A vector motor control scheme is a computationally intensive motor control scheme that maps the phase voltages/currents of a three-phase motor into a two axis coordinate system (D and Q axes). The structure used to excite an electric motor using a vector control scheme is a typical three phase power source inverter including six power transistors that shape the output voltage to an electric motor. Vector control requires rotor position information, which is normally obtained via a feedback device or position sensor. The objective of the position sensorless control is to obtain the rotor position information utilizing electromagnetic characteristics of an AC machine, eliminating the position sensor and its associated interface circuits.
SUMMARY OF THE INVENTION
The present invention is a method and apparatus for a sensorless motor control system used in electric and hybrid electric vehicle powertrain applications. The motor control system of the present invention calculates the current components on the d
m
and q
m
measurement axes used in the rotor position estimator using a moving average filter that improves execution time and allows relatively high bandwidth and improved transient response of the motor control system.
REFERENCES:
patent: 6601011 (2003-07-01), Miyamoto et al.
Patel Nitinkumar R.
Schulz Steven E.
DeVries Christopher
General Motors Corporation
Masih Karen
LandOfFree
Amplitude detection method and apparatus for high frequency... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Amplitude detection method and apparatus for high frequency..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Amplitude detection method and apparatus for high frequency... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3253695