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US5296793A Expired / Lapsed US ⏱️ 0.0 years remaining

State observer for synchronous motors

Assignee: Massachusetts Institute of Technology
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Filing: 1986-11-05
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Granted: 1994-03-22
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Expires: 2006-11-05
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Abstract

Abstract A state observer driven by measurements of phase voltages and currents for estimating the angular orientation of a rotor of a synchronous motor such as a variable reluctance motor (VRM). Phase voltages and currents are detected and serve as inputs to a state observer. The state observer includes a mathematical model of the electromechanical operation of the synchronous motor. The characteristics of the state observer are selected so that the observer estimates converge to the actual rotor angular orientation and velocity, winding phase flux linkages or currents.

Inventors

  • 👤 Jeffrey H. Lang

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 17:00
CPC Classifications
H; H02; H02P; H02P21/00; H02P21/14; H02P21/141; H02P25/00; H02P25/02; H02P25/08; H02P25/086; H02P25/089

Claims Analysis

Total Claims: 17
Claim 1
Independent Claim 92 words
Controller for a synchronous motor comprising: means for measuring motor phase voltages and currents, computing means responsive to the motor phase voltages and currents for calculating estimates of rotor angular orientation from observer model equations derived from state equations of the motor and adapted to have stable dynamics, whereby the estimates of rotor angular orientation converge to values of actual rotor angular orientation, and means responsive to said estimates of rotor angular orientation for controlling the motor pulse voltages, whereby motor phases are excited substantially in synchronism with the rotor angular orientation.
Claim 2
Dependent Claim 92 words
Controller for a synchronous motor comprising: means for measuring motor phase voltages and currents, computing means responsive to the motor phase voltages and currents for calculating estimates of rotor angular orientation from observer model equations derived from state equations of the motor and adapted to have stable dynamics, whereby the estimates of rotor angular orientation converge to values of actual rotor angular orientation, and means responsive to said estimates of rotor angular orientation for controlling the motor pulse voltages, whereby motor phases are excited substantially in synchronism with the rotor angular orientation.
Claim 3
Dependent Claim 13 words
The controller of claim 1 wherein the motor is a variable reluctance motor.
Claim 4
Dependent Claim 13 words
The controller of claim 1 wherein the motor is a permanent magnet motor.
Claim 5
Dependent Claim 15 words
The controller of claim 1 wherein the motor is a magnetically linear variable reluctance motor.
Claim 6
Dependent Claim 81 words
The controller of claim 1 wherein the motor is a variable reluctance motor and the observer model equations take the form of: λ'=-RH(θ)λ+ν+F.sub.λ (θ,λ)(i-i) ω'=F.sub.ω (θ,λ)(i-i) θ'=ω=F.sub.θ (θ,λ)(i-i) i=H(θ)λ, wherein λ, ν, i, R, and H represent phase flux linkages, voltages, currents, resistances, and reciprocal inductances respectively, ω, θ, D, and J represent rotor velocity, angular orientation, damping, and inertia, respectively, tilde denotes an estimate, prime denotes a first derivative, and F.sub.λ, F.sub.ω, and F.sub.θ are functions selected to assure stability.
Claim 7
Dependent Claim 138 words
Controller for a synchronous motor comprising: means for detecting motor phase voltages and currents, computing means for calculating estimates of rotor angular orientation from observer model equations of the form: λ'=-RH(θ)λ+ν+F.sub.λ (θ,λ)(i-i) ω'=F.sub.ω (θ,λ)(i-i) θ'=ω=F.sub.θ (θ,λ)(i-i) i=H(θ)λ, wherein λ, ν, i, R, and H represent phase flux linkages, voltages, currents, resistances, and reciprocal inductances respectively, ω, θ, D, and J represent rotor velocity, angular orientation, damping, and inertia, respectively, tilde denotes an estimate, prime denotes a first derivative, and F.sub.λ, F.sub.ω, and F.sub.θ are functions selected to assure stability, whereby the estimates of rotor angular orientation θ converge to values of actual rotor angular orientation θ, and means responsive to said estimates of rotor angular orientation for controlling the phase voltages of the motor, whereby the motor phases are excited substantially in synchronism with the rotor angular orientation.
Claim 8
Dependent Claim 138 words
Controller for a synchronous motor comprising: means for detecting motor phase voltages and currents, computing means for calculating estimates of rotor angular orientation from observer model equations of the form: λ'=-RH(θ)λ+ν+F.sub.λ (θ,λ)(i-i) ω'=F.sub.ω (θ,λ)(i-i) θ'=ω=F.sub.θ (θ,λ)(i-i) i=H(θ)λ, wherein λ, ν, i, R, and H represent phase flux linkages, voltages, currents, resistances, and reciprocal inductances respectively, ω, θ, D, and J represent rotor velocity, angular orientation, damping, and inertia, respectively, tilde denotes an estimate, prime denotes a first derivative, and F.sub.λ, F.sub.ω, and F.sub.θ are functions selected to assure stability, whereby the estimates of rotor angular orientation θ converge to values of actual rotor angular orientation θ, and means responsive to said estimates of rotor angular orientation for controlling the phase voltages of the motor, whereby the motor phases are excited substantially in synchronism with the rotor angular orientation.
Claim 9
Dependent Claim 14 words
The controller of claim 6 wherein the synchronous motor is a variable reluctance motor.
Claim 10
Dependent Claim 8 words
The controller of claim 6 wherein F.sub.λ =R.
Claim 11
Dependent Claim 14 words
The controller of claim 6 wherein G.sub.ω and G.sub.θ are positive constants wherein ##EQU8##
Claim 12
Dependent Claim 85 words
Controller for a synchronous motor comprising: means for measuring motor phase voltages and currents, computing means responsive to the motor phase voltages and currents for calculating estimates of rotor angular velocity from observer model equations derived from state equations of the motor and adapted to have stable dynamics, whereby the estimates of rotor angular velocity converge to values of actual rotor angular velocity, and means responsive to said estimates of rotor angular velocity for controlling the motor phase voltages for synchronous excitation of the motor.
Claim 13
Dependent Claim 85 words
Controller for a synchronous motor comprising: means for measuring motor phase voltages and currents, computing means responsive to the motor phase voltages and currents for calculating estimates of rotor angular velocity from observer model equations derived from state equations of the motor and adapted to have stable dynamics, whereby the estimates of rotor angular velocity converge to values of actual rotor angular velocity, and means responsive to said estimates of rotor angular velocity for controlling the motor phase voltages for synchronous excitation of the motor.
Claim 14
Dependent Claim 85 words
Controller for a synchronous motor comprising: means for measuring motor phase voltages and currents, computing means responsive to the motor phase voltages and currents for calculating estimates of phase flux linkages from observer model equations derived from state equations of the motor and adapted to have stable dynamics, whereby the estimates of phase flux linkages converge to values of actual phase flux linkages, and means responsive to said estimates of phase flux linkages for controlling the motor phase voltages for synchronous excitation of the motor.
Claim 15
Dependent Claim 85 words
Controller for a synchronous motor comprising: means for measuring motor phase voltages and currents, computing means responsive to the motor phase voltages and currents for calculating estimates of phase flux linkages from observer model equations derived from state equations of the motor and adapted to have stable dynamics, whereby the estimates of phase flux linkages converge to values of actual phase flux linkages, and means responsive to said estimates of phase flux linkages for controlling the motor phase voltages for synchronous excitation of the motor.
Claim 16
Dependent Claim 81 words
Controller for a synchronous motor comprising: means for measuring motor phase voltages and currents, computing means responsive to the motor phase voltages and currents for calculating estimates of motor currents from observer model equations derived from state equations of the motor and adapted to have stable dynamics, whereby the estimates of motor currents converge to values of actual motor currents, and means responsive to said estimates of motor currents for controlling the motor phase voltages for synchronous excitation of the motor.
Claim 17
Dependent Claim 81 words
Controller for a synchronous motor comprising: means for measuring motor phase voltages and currents, computing means responsive to the motor phase voltages and currents for calculating estimates of motor currents from observer model equations derived from state equations of the motor and adapted to have stable dynamics, whereby the estimates of motor currents converge to values of actual motor currents, and means responsive to said estimates of motor currents for controlling the motor phase voltages for synchronous excitation of the motor.

References Cited (Backward Citations)

US3896351A Cited
US4388577A Cited
US4423367A Cited
US4511978A Cited
US4442393A Cited
US4678248A Cited
US4649331A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-03-21 1997-09-20 1998-03-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-03-21 2001-09-20 2002-03-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-03-21 2005-09-20 2006-03-22 $7700.00 Window Closed / Lapsed

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