Eaton Corporation

Siemens Energy & Automation, Inc.

General Electric Company

United States of America as Represented by the Secretary of the Air Force

Square D Company

Schneider Electric USA, Inc.

Thomas G Habetler

Bin Lu

Ronald Gordon Harley

Steven Andrew Dimino

Slobodan Krstic

Michael P Nowak

Yanzhen Liu

Pinjia Zhang

Ramzy R Obaid

Gerald Burt Kliman

Peter J Theisen

David J Gritter

Marcus Alex Cash

Randy Schoen

Charles John Luebke

Roy Stephen Colby

Samir F Farag

Yi Yang

Sang-Bin Lee

Zhi Gao

Wei Zhou

Liang Du

Dawei He

Marcus A Cash

Scott K Becker

Rangarajan M Tallam

Jay H Schlag

Ronald G Harley

Ronald Harley

A system is for a plurality of different electric load types. The system includes a plurality of sensors structured to sense a voltage signal and a current signal for each of the different electric loads; and a processor. The processor acquires a voltage and current waveform from the sensors for a corresponding one of the different electric load types; calculates a power or current RMS profile of the waveform; quantizes the power or current RMS profile into a set of quantized state-values; evaluates a state-duration for each of the quantized state-values; evaluates a plurality of state-types based on the power or current RMS profile and the quantized state-values; generates a state-sequence that describes a corresponding finite state machine model of a generalized load start-up or transient profile for the corresponding electric load type; and identifies the corresponding electric load type.

Method and system employing finite state machine modeling to identify one of a plurality of different electric load types

A system and method for determining electric motor efficiency includes a monitoring system having a processor programmed to determine efficiency of an electric motor under load while the electric motor is online. The determination of motor efficiency is independent of a rotor speed measurement. Further, the efficiency is based on a determination of stator winding resistance, an input voltage, and an input current. The determination of the stator winding resistance occurs while the electric motor under load is online.

System and method to determine electric motor efficiency using an equivalent circuit

A system and method for detecting a rotor fault condition in an AC induction machine is disclosed. The system includes a processor programmed to receive voltage and current data from an AC induction machine, generate a current frequency spectrum from the current data, and identify rotor-fault related harmonics in the current frequency spectrum. The processor is also programmed to calculate a fault severity indicator using the voltage and current data, identified rotor-fault related harmonics, and motor specifications, analyze the fault severity indicator to determine a possibility of rotor fault. The processor generates an alert based on the possibility of rotor fault.

System and method for detecting fault in an AC machine

A system and method for determining the stator winding resistance of AC motors is provided. The system includes an AC motor drive having an input connectable to an AC source and an output connectable to an input terminal of an AC motor, a pulse width modulation (PWM) converter having switches therein to control current flow and terminal voltages in the AC motor, and a control system connected to the PWM converter. The control system generates a command signal to cause the PWM converter to control an output of the AC motor drive corresponding to an input to the AC motor, selectively generates a modified command signal to cause the PWM converter to inject a DC signal into the output of the AC motor drive, and determines a stator winding resistance of the AC motor based on the DC signal of at least one of the voltage and current.

System and method for determining stator winding resistance in an AC motor using motor drives

A system and method for measuring and controlling stator winding temperature in an AC motor while idling is disclosed. The system includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of a multi-phase AC motor. The circuit further includes a plurality of switching devices to control current flow and terminal voltages in the multi-phase AC motor and a controller connected to the circuit. The controller is configured to activate the plurality of switching devices to create a DC signal in an output of the motor control device corresponding to an input to the multi-phase AC motor, determine or estimate a stator winding resistance of the multi-phase AC motor based on the DC signal, and estimate a stator temperature from the stator winding resistance. Temperature can then be controlled and regulated by DC injection into the stator windings.

System and method for monitoring and controlling stator winding temperature in a de-energized AC motor

A system and method for nonintrusively determining electric motor efficiency includes a processor programed to, while the motor is in operation, determine a plurality of stator input currents, electrical input data, a rotor speed, a value of stator resistance, and an efficiency of the motor based on the determined rotor speed, the value of stator resistance, the plurality of stator input currents, and the electrical input data. The determination of the rotor speed is based on one of the input power and the plurality of stator input currents. The determination of the value of the stator resistance is based on at least one of a horsepower rating and a combination of the plurality of stator input currents and the electrical input data. The electrical input data includes at least one of an input power and a plurality of stator input voltages.

System and method to determine electric motor efficiency nonintrusively

A system and method for determining stator winding resistance in an AC motor is disclosed. The system includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of an AC motor. The circuit includes at least one contactor and at least one switch to control current flow and terminal voltages in the AC motor. The system also includes a controller connected to the circuit and configured to modify a switching time of the at least one switch to create a DC component in an output of the system corresponding to an input to the AC motor and determine a stator winding resistance of the AC motor based on the injected DC component of the voltage and current.

System and method for determining stator winding resistance in an AC motor

A system and method for detecting incipient mechanical motor faults by way of current noise cancellation is disclosed. The system includes a controller configured to detect indicia of incipient mechanical motor faults. The controller further includes a processor programmed to receive a baseline set of current data from an operating motor and define a noise component in the baseline set of current data. The processor is also programmed to repeatedly receive real-time operating current data from the operating motor and remove the noise component from the operating current data in real-time to isolate any fault components present in the operating current data. The processor is then programmed to generate a fault index for the operating current data based on any isolated fault components.

System and method for bearing fault detection using stator current noise cancellation

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.

Electronic overload relay for mains-fed induction motors

The present invention is directed to a system and method for proactively determining motor wellness arising from potential mechanical faults of the motor. A controller is configured to detect indicia of impending mechanical motor faults. The controller includes a processor configured to determine motor parameters of a given motor including a load and generate a set of baseline data for the given motor. The processor is also configured to acquire current spectrum data from the given motor during operation, map at least one from a plurality of load bins based on the load, and generate a mechanical fault signature from the current spectrum. The processor is caused to compare the mechanical fault signature to baseline data from the set of baseline data corresponding to the mapped bin and determine amplitude variances within the mechanical fault signature indicative of an impending mechanical fault prior to an actual mechanical fault occurrence.

System and method for proactive motor wellness diagnosis based on potential mechanical faults

The present invention is directed to a power meter or overload relay including a housing and a plurality of sensors configured to monitor operation of a motor. A processor disposed within the housing and configured to receive operational feedback from the plurality of sensor and proactively determine an operational wellness of the motor from the operational feedback.

System and method for proactive motor wellness diagnosis

The present invention is directed to a condition monitoring system for determining internal motor fault information. Voltage and current data are acquired from an induction machine in operation. Reactive and real power delivered to the induction machine is then determined from the voltage and current data. An inspection of the frequency spectrum of the real power as well as the reactive power is then used to ascertain load and motor condition. Specifically, an analysis of the frequency spectrum of the reactive power may be inspected for information relating to an internal motor fault whereas the frequency spectrum of the real power may be inspected for information relating to motor-driven or load faults.

Growing community of inventors

Snellville, GA, United States of America

Thomas G Habetler