Schneider Electric Usa, Inc.

Otis Elevator Company

Square D Company

Other

United Technologies Corporation

Roy Stephen Colby

Zhi Gao

Larry A Turner

Alberto Vecchiotti

Mark Kocher

Gerald Benjamin Carson

Leslie M Lamontagne

Paul Robert Buda

Scott Robert Brown

Neil A Greiner

Zbigniew Piech

Randall Keith Roberts

Timothy B Phillips

Colin N Gunn

Thomas G Habetler

Ronnie E Thebeau

Alexander Filippenko

Ronald Gordon Harley

Timothy M Remmers

Benoit Leprettre

Rajesh Rajamani

Robert J Dwulet

Marc Bruel

Kyle P Hunter

Scott Robert Littler

Robert Gregory Oldham

Mark John Kocher

Colin Gunn

Ronald G Harley

Motor overload protection device is equipped with a thermal monitor that can determine expected rotor temperature rise from rotor resistance estimates. The thermal monitor determines expected rotor temperature rise by using a correlation between rotor temperature rise computed from rotor resistance estimates, and motor thermal state estimates. The correlation can be derived by fitting a line to a plurality of points, with each point defined by an ordered pair composed of a rotor temperature rise estimate and a corresponding motor thermal state estimate, and determining a slope of the line. This rotor temperature slope can then be used by the thermal monitor to determine a rotor temperature rise given a rotor resistance estimate and a corresponding motor thermal state estimate. If the rotor temperature rise exceeds an expected rotor temperature rise by more than a predefined threshold, the thermal monitor issues an alarm and/or takes corrective actions in some embodiments.

Rotor resistance based motor thermal protection

A system and method to detect an onset of motor rotation for an induction motor. The system and method involves monitoring a power supplied to a motor via a sensor, determining a power quantity based on the power monitored by the sensor, detecting an envelope of the power quantity, detecting an onset of rotation of the motor when an amplitude of the envelope has increased, and inhibiting power flow to the motor when the onset of rotation does not occur within a predetermined time period or logging a first time period of the detected onset of rotation of the motor for use in monitoring the condition of the motor. The power quantity can be a current vector magnitude or an instantaneous power corresponding to the supplied power.

Detection of initial motor rotation in mains-fed induction motor

According to one aspect, embodiments of the invention provide a power meter comprising a voltage sensor, at least one current and phase sensor circuit, and a central metering unit, wherein the voltage sensor is further configured to measure a voltage on an input line and transmit a signal related to the voltage to the central metering unit, wherein the at least one current and phase sensor circuit is further configured to measure a current and a voltage phase shift of a feeder line, and to transmit a signal related to at least one of the current of the feeder line and the voltage phase shift of the feeder line to the central metering unit, and wherein the central metering unit is configured to calculate power provided to a load via the feeder line based on the signal transmitted from the at least one current and phase sensor circuit.

Power meter with current and phase sensor

A method and apparatus to dynamically and adaptively demodulate induction motor instantaneous rotor slot harmonic frequency for line-connected squirrel-cage polyphase induction motors. The instantaneous rotor slot harmonic frequency carries essential information on the instantaneous rotor speed. Based on a correlation between the motor's input power and its rotor slot harmonic frequency, a dynamically varying carrier frequency is computed and used in a rotor slot harmonic frequency detector. The rotor slot harmonic frequency detector is based on a superheterodyne principle. It contains a generalized linear-phase low-pass filter, whose bandwidth is estimated dynamically by a filter bandwidth estimator. The rotor slot harmonic frequency detector also includes a latency compensator, which receives the dynamically varying carrier frequency signal and synchronizes it with the output of a frequency demodulator.

Systems, methods, and devices for demodulating induction motor instantaneous rotor slot harmonic frequency

A method of automatically detecting an anomalous condition relative to a nominal operating condition in a vapor compression system. An expected input power function in the form of a hyperplane is calculated based on three temperature readings: an intake temperature from an intake area of the condenser unit, a return temperature from an intake area of an evaporator unit, and a supply temperature from a supply output area of the evaporator unit. The function produces an estimate of the expected input power consumed by the compressor unit, and this expected input power is compared with an actual input power measured from the compressor unit. If the expected input power deviates from the measured input power by more than a predetermined tolerance, an indication is stored and communicated that an anomalous condition, such as a refrigerant loss, condenser unit fouling, or a malfunctioning fan, exists in the vapor compression system.

Method of automatically detecting an anomalous condition relative to a nominal operating condition in a vapor compression system

A system and method of measuring atmospheric parameters in an enclosed space using instrumented objects having measurement sensors. The instrumented objects travel through the space randomly or along defined flight paths. As the instrumented objects travel through the space, the measurement sensors measure atmospheric parameters and store the measurements to a memory. The devices periodically upload the measured atmospheric parameters to a controller circuit. By using self-propelled objects to carry measurement sensors, the system and method disclosed herein allow for periodically sampling atmospheric parameters in the interior of an enclosed space at a number of locations greater than the number of measurement devices employed. With data points taken from various locations within a volume of an enclosed space, the system and method can realize a more efficient utilization of energy by adjusting mechanical controls of an HVAC system or a ventilation system, for example.

System and method for measuring atmospheric parameters in enclosed spaces

Methods and devices are presented herein for estimating induction motor inductance parameters based on instantaneous reactive power. The induction motor inductance parameters, e.g., the stator inductance and the total leakage factor, can be estimated from motor nameplate data and instantaneous reactive power without involving speed sensors or electronic injection circuits. In one embodiment, the method includes: measuring voltages and currents; converting the measured voltages and currents into discrete-time voltage and current samples by analog-to-digital converters; synthesizing a complex voltage from the discrete-time voltage samples; synthesizing a complex current from the discrete-time current samples; acquiring and storing motor nameplate data; detecting instantaneous rotor speed by calculating an instantaneous rotor slot harmonic frequency with respect to an instantaneous fundamental frequency; calculating, via an induction motor inductance estimator, the motor's instantaneous reactive power and other intermediate quantities; and outputting the stator inductance and the total leakage factor.

Methods and devices for estimation of induction motor inductance parameters

Methods of determining a quantity of rotor slots in an induction motor are disclosed. An approximate slip is calculated according to an approximate slip function. A fundamental frequency is calculated from a representation of the voltage signal. A saliency frequency is calculated from a representation of the current signal. For each rotor slots index in a set of rotor slots indices, a slip estimate is calculated according to a slip estimation function. A slip estimation error signal is calculated. A rotor slots performance surface representative of an aggregate of the slip estimation error signals is calculated. A rotor slots quantity equal to the rotor slots index corresponding to a minimum of the rotor slots performance surface over at least a portion of the set of the rotor slots indices is defined.

Methods and apparatus for estimating rotor slots

A method of determining a quantity of rotor slots in an induction motor through analysis of voltage and current signals. An approximate slip is calculated according to an approximate slip function that is independent of a rotor slots quantity. A fundamental frequency is calculated from a representation of the voltage signal. A saliency frequency is calculated from a representation of the current signal. For each rotor slots index in a set of rotor slots indices, a slip estimate is calculated according to a slip estimation function that includes the saliency frequency, a saliency order, the fundamental frequency, a rotor slots index in the set of rotor slots indices, and a quantity of poles of the motor, such that the slip estimate is evaluated at respective ones of the set rotor slots indices. A slip estimation error signal is calculated according to a slip estimation error function that includes a difference between the approximate slip and respective ones of the slip estimates. A rotor slots performance surface representative of an aggregate of the slip estimation error signals evaluated over the set of the rotor slots indices is calculated. A rotor slots quantity equal to the rotor slots index corresponding to a minimum of the rotor slots performance surface over at least a portion of the set of the rotor slots indices is defined.

A method and apparatus to provide estimates of electrical parameters for line-connected induction motors during either steady-state or dynamic motor operations. The electrical parameters are calculated from the motor nameplate data and voltage and current measurements. No speed sensors or electronic injection circuits are needed. The method can be divided into 4 major steps. First, complex space vectors are synthesized from voltage and current measurements. Second, the instantaneous rotor speed is detected by calculating the rotational speed of a single rotor slot harmonic component with respect to the rotational speed of the fundamental frequency component. Third, the positive sequence fundamental frequency components are extracted from complex space vectors. Finally, least-squares estimates of the electrical parameters are determined from a dynamic induction motor equivalent circuit model.

Method and apparatus for estimating induction motor electrical parameters

A method of determining a slip estimate associated with an induction motor through analysis of voltage and current signals. A fundamental frequency is calculated from a representation (e.g., complex representation) of the voltage signal, and a saliency frequency is calculated from a representation of the current signal. An estimation of slip quantity is calculated according to a slip estimation function that includes the saliency frequency, a saliency order, the fundamental frequency, a quantity of rotor slots, and a quantity of poles of the motor.

Methods and apparatuses for estimating transient slip

Devices and methods of commodity usage monitoring determine the amount of commodity used by individual elements of multi-element systems having a common source. An amount of commodity drawn from the source by all the users is determined. A user-state that indicates use of the commodity by each user is determined. Individual user consumption of the commodity for each of the users is determined using repeated determinations of the amount of the commodity and the user-state, for a number of repetitions greater than or equal to the number of users. Determining individual consumption can be performed using minimum least square estimation, singular value decomposition, discriminant function analysis, or other computational or analytical solution method. Duration and consumption information can be used to calculate the total amount of the commodity consumed by the particular user. Useful commodities include, but are not limited to, gas, electricity, mechanical, pneumatic, hydraulic, and water.

Devices and methods for determining the amount of individual usage of a shared commodity

A method and apparatus to provide continuous and reliable rotor temperature estimates for line-connected induction motors during steady-state and/or dynamic motor operations. Rotor temperature is calculated from voltage and current measurements without any temperature or speed sensors. First, complex space vectors are synthesized from voltage and current measurements. Second, the instantaneous rotor speed is detected by calculating the rotational speed of a single rotor slot harmonic component with respect to the rotational speed of the fundamental frequency component. Third, the positive sequence fundamental frequency components are extracted from complex space vectors. Fourth, the rotor time constant is estimated in a model-reference adaptive system based on a dynamic induction motor equivalent circuit model. Finally, the rotor temperature is calculated according to the linear relationship between the rotor temperature and the estimated rotor time constant. Real-time induction motor thermal protection is achieved through this continuous tracking of the rotor temperature.

Method and apparatus for estimating induction motor rotor temperature

A phase locked loop (PLL) circuit provides ac devices, such as power inverters and power measurement devices, with a reliable means for synchronizing to ac electrical systems. In an exemplary embodiment, the PLL circuit is configured for operation with single-phase electrical systems and offers substantial noise immunity by basing its locking operations on measured fundamental components, i.e., measured x-y phasors, of the electrical system voltage. Further, with its phasor-based locking operations and with its timer/counter-based operation, the PLL circuit can be implemented partly or wholly in digital processing logic.

Method and apparatus for signal phase locking

An induction motor having a rotor and a stator is protected during running overloads by connecting the motor to an overload protection relay that can be tripped to interrupt power to the motor in the event of an overload, tracking the stator winding temperature of the motor during running overloads with a hybrid thermal model by online adjustment in the hybrid thermal model, and tripping the overload protection relay in response to a predetermined running overload condition represented by the tracked stator winding temperature. In one embodiment of the invention, the stator winding temperature is tracked by use of an online hybrid thermal model that uses the resistance of the rotor as an indicator of rotor temperature and thus of the thermal operating conditions of the motor. The hybrid thermal model incorporates rotor losses and heat transfer between the rotor and the stator, and approximates the thermal characteristics of the rotor and stator.

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Raleigh, NC, United States of America

Roy Stephen Colby