Sundstrand Corporation

Hamilton Sundstrand Corporation

Sunstrand Corporation

Albert L Markunas

Gregory I Rozman

Vijay K Maddali

Michael J Hanson

Leland E Weber

Charles J Romenesko

Dhaval S Patel

Alexander Cook

Paul E Nuechterlein

Vietson M Nguyen

Michael C Harke

John F Defenbaugh

Madan L Bansal

James A Shippling

Timothy F Glennon

Daniel M Saban

Donal E Baker

William E Seidel

John Duward Sagona

Shan-Chin Tsai

Malcolm J McArthur

Wesley A Burandt

Dennis T Faulkner

Mordehy Cohen

David A Fox

James J Wrobel

Jun Hu

Richard A Arbanella

William J Peterson

Thomas A Nelson

Jason A Ohnemus

Kenneth R Carr

Mario R Rinaldi

Vijay K Madalli

Christopher E Hopkins

Apparatus and associated methods relate to active damping of mechanical oscillations of a synchronous generator's drivetrain by modulating an excitation signal provided to the synchronous generator in proper phase relation with detected mechanical oscillations so as to dampen these oscillations. The excitation signal includes a superposition of a voltage-regulation signal and an active-damping signal. The voltage-regulation signal is configured to regulate an output voltage of electrical power provided by the synchronous generator, and the active-damping signal is configured to provide active damping to the drivetrain of the mechanical system that includes the synchronous generator. The active-damping signal is generated by detecting mechanical oscillations of the drivetrain, filter such detected mechanical oscillations such that the active-damping signal has a proper phase relationship with the mechanical oscillations over a predetermined range of frequencies. This proper phase relationship is maintained over the range of frequencies using a second order lag/lead filter.

Active damping of mechanical drivetrain oscillations using generator voltage regulator

A brushless, three phase wound field synchronous machine (WFSM) provides an electromechanical power transfer system wherein it may serve as both a starter and a generator. Power for the excitation system of the WFSM is provided by a three phase flux switching generator (FSG). The three phase FSG also provides position sensor functionality for the WFSM when the WFSM operates in the starter/motor mode.

Three phase flux switching generator in a three stage wound field synchronous machine

A rotor position determination and tracking system for a dynamo electric machine includes a first AC power supply to inject a carrier wave into a main stator of the dynamoelectric machine and a second AC power supply to inject an excitation voltage or current into an exciter stator of the dynamoelectric machine. A plurality of current sensors and voltage sensors located at the exciter input lines sense current and voltage thereat. A first control logic receives the sensed current and voltage and outputs an estimated rotor position. A second control logic receives an estimated exciter field voltage or current rotating wave form angle and filtered sensed current or voltage signals from the first control logic and utilizes a known main stator carrier frequency to determine the rotor position. The rotor position is input into the first control logic to calibrate the first control logic for tracking of the true rotor position.

Sensorless rotor position determination for a wound field synchronous machine

An example method of initiating operation of a wound field synchronous machine in a motoring mode includes estimating an initial position of a rotor of a wound field synchronous machine using a carrier injection sensorless stimulation signal. The method tracks an operating position of the rotor based on current harmonics of the wound field synchronous machine. The method also calibrates the tracking using the initial position.

Wound field synchronous machine rotor tracking using a carrier injection sensorless signal and exciter current

A method of operating a WFSM in a motoring mode determines a relative position of a PMG rotor with respect to the WFSM rotor. A PMG is coupled to the WFSM via a coupling shaft. A relative difference between the WFSM rotor position and the PMG rotor position is determined based on carrier injection sensorless ('CIS') stimulation signals. The relative difference between the PMG rotor and the WFSM main machine in conjunction with the PMG rotor position is used to determine the WFSM rotor position during motoring operation of the main machine. A stator of the WFSM main machine is energized to maintain operation of the WFSM in response to the detected main rotor position.

Rotor position detection at standstill and low speeds using a PMG to operate a wound field synchronous machine

An electric load damper assembly includes a synchronous generator operable to provide a plurality of phases of electrical output in response to a mechanical input from a rotating shaft. An electric load damper includes a phase leg for each of the plurality of phases. Each phase leg includes a resistive load, a snubber and at least one solid state switch. The at least one solid state switch is in parallel with the snubber, and the at least one solid state switch and snubber are collectively in series with the resistive load. A controller is operable to receive a signal indicative of a rotational speed oscillation of the synchronous generator, and is operable to selectively reduce a torsional oscillation of the shaft by diverting electrical current from the synchronous generator through the resistive load of each of the plurality of phases in response to the signal exceeding a predefined threshold.

Electric load damper for damping torsional oscillation

A variable speed drive for an electric motor has an inverter for receiving pulse width modulation controls. The inverter communicates power signals to a poly-phase electrical motor. A resolver communicates signals from the poly-phase motor back to a motor control. The motor control includes a speed control, a field-oriented control, and a pulse width modulation drive for driving the inverter. The resolver is connected to the speed control and to the field-oriented control, and further communicates with a synchronous compensator. The synchronous compensator is configured to drive the harmonic content at a target frequency or frequencies in a selected signal towards zero over time.

Synchronous disturbance suppression in a variable speed motor drive

A method of detecting and monitoring torsional oscillation in a mechanical coupling between a prime mover and a multiphase alternating current (AC) electrical generator, comprises the steps of: detecting in at least one received signal variations that are indicative of changes in the rotational speed of the electrical generator; extracting information from the detected variations that are indicative of torsional oscillation to produce a torsional oscillation signal that has information relating to at least the amplitude of the torsional oscillation; and monitoring the torsional oscillation signal to determine the presence and severity of the torsional oscillation in the mechanical coupling.

Torque oscillation monitoring

A generator control unit (GCU) provides active damping of a synchronous generator by monitoring the speed of the synchronous generator and detecting oscillations in the monitored speed. The oscillations are indicative of torsional oscillations within the mechanical drivetrain including the synchronous generator or generators. In response to detected oscillations in the monitored speed, the GCU generates a varying set-point value that is used to control the excitation voltage provided to the synchronous generator. Varying the excitation voltage provided to the synchronous generator causes a variation in synchronous generator torque. By selectively varying the torque in the synchronous generator, the GCU provides active damping in the synchronous generator that decreases or dampens the torsional oscillations.

Active damping for synchronous generator torsional oscillations

For a multiphase alternating current (AC) wound field synchronous machine (WFSM) that has a stator with a selected number of poles, the WFSM having an associated exciter and multiphase AC permanent magnet machine (PMM) directly coupled to the WFSM, a method of sensing the position of a rotor in the WFSM comprises the steps of: configuring a stator for the PMM to have a number of poles that is a sub-multiple of the selected number of WFSM stator poles; configuring a rotor for the PMM to have high saliency; applying multiphase AC power of a selected frequency to the PMM stator; detecting at least one set of stator harmonic currents of the multiphase AC power resulting from the rotor saliency; converting the detected PMM harmonic stator currents from their multiphase coordinates to &#x3b1;&#x3b2; coordinates; rotating the converted PMM stator currents into a reference frame for at least one selected harmonic to generate &#x3b1;&#x3b2; coordinate harmonic current vectors; and estimating the position of the WFSM rotor based on the values of the &#x3b1;&#x3b2; coordinate harmonic current vectors in the selected harmonic reference frame.

Rotor position detection at standstill and low speeds using a low power permanent magnet machine

A method of correcting the determination of extended rotor flux using a lag function and a correction algorithm that closely approximates a pure integrator function to correct for lag function errors that can extend the EFS control down to dynamoelectric machine speeds corresponding to as low as 10 Hz electrical frequency.

Angular position and velocity estimation for synchronous machines based on extended rotor flux

A field oriented control system for a brushless wound field synchronous machine that determines positioning of a rotor for the machine from exciter stator electrical potentials and current harmonics.

Brushless wound field synchronous machine rotor position tracking with exciter stator current harmonic tracking

A shaft sensorless rotor angular position and velocity sensing system for a ynamoelectric machine that includes: a reference frame transformation function for transforming measured currents and potentials applied to a stator of the dynamoelectric machine to a two-phase &#x3b1;-&#x3b2; stationary frame to produce transformed currents I,Iand transformed potentials V,V; first and second multipliers to produce signals I*R,I*R; first and second summers to produce signals V,&#x2212;I*R,V&#x2212;I*R; first and second lag functions to produce signals third and fourth multipliers to produce signals I*L,I*L; third and fourth summers to produce signals that correspond to extended rotor flux values &#x3bb;,&#x3bb;; and a phase lock loop (PLL) to derive estimated rotor angular position and velocity values {circumflex over (&#x3b8;)}, {circumflex over (&#x3c9;)} for the dynamoelectric machine from the extended rotor flux values &#x3bb;,&#x3bb;.

Shaft sensorless angular position and velocity estimation for a dynamoelectric machine based on extended rotor flux

A carrier injection sensorless (CIS) starting control system that is capable of determining the angular position and velocity of a rotor for a wound field synchronous machine at or near rest and comprises north-south pole determination and a variable or dual frequency carrier signal for improved performance throughout the start sequence for the machine.

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Roscoe, IL, United States of America

Albert L Markunas