Otis Elevator Company

Neil A Greiner

Roy Stephen Colby

Alberto Vecchiotti

Ronnie E Thebeau

Daryl J Marvin

Edward D Piedra

Christopher S Czerwinski

Leslie M Lamontagne

The temperature ( ) of solid state switching devices in variable speed motor drives ( ), such as elevator motor drives, are utilized to reduce the load on the drive, by reducing the switching frequency ( ) or the commanded load ( ). The choice between the preferred non-switching zero state and an alternative zero state is determined ( ) by temperature ( ) of the switched transistor's anti-parallel diode. The rate of recognizing reduced temperatures is limited ( ) to avoid motor speed and/or load variations. The temperature may either be measured ( ) or determined ( ) from models utilizing manufacturer product specification and normalized thermal transient response from the transistor/diode package to a heat sink.

Motor drive parameters

A self-commissioning controller 7 for a field-oriented elevator motor controller 14 includes calculating an integral gain K.sub.I, a proportional gain Kp, and an overall gain (Gc) for the motor controller; obtaining initial values of a rotor time constant .tau..sub.R, magnetizing current Id, and motor torque constant K.sub.T for the motor controller 14, and obtaining a value of a motor transient inductance L.sigma.; calculating final values for said rotor time constant .tau..sub.R and magnetizing current Id, using said transient inductance L.sigma.; and calculating a system inertia J* parameter for speed loop compensation 16 within the motor controller 14. The controller 7 may also include calculating the initial values for .tau..sub.R, Id, and K.sub.T *, and performing self-commissioning automatically upon receiving a command from a service tool 80.

Self commissioning controller for field-oriented elevator motor/drive

An elevator controller 7 is provided with logic 48 which automatically calculates a motor time constant (.tau..sub.R) for a field-oriented current regulator/motor drive 20 by running the elevator up and down while computing an average of a sign-adjusted error signal DXD.sub.ERR for the up/down run and while varying .tau..sub.R and determining the value of .tau..sub.R at which the average of DXD.sub.ERR for the up and down runs equals zero within a predetermined tolerance. Alternatively, instead of computing the average of DXD.sub.ERR, a single elevator run may be used to determine the value of .tau..sub.R at which DXD.sub.ERR equals zero within a predetermined tolerance.

Automatic fine tuning of rotor time constant in field-oriented elevator

Growing community of inventors

Wethersfield, CT, United States of America

Neil A Greiner