US 10,852,356 B2 · Method for magnetic burst testing of large electric motors with portable tester powered by a domestic wall outlet

Abstract

A method for magnetic/impedance burst testing of large electric motors to determine broken rotor bar defect. The method providing a portable tester and includes a Signal Processor, a single-phase power source VAC, an AC/DC boost converter connected to the power source, at least one energy storage device connected to the AC to DC boost converter, a Pulse Width Modulated drive module (PWM) connected to the at least one energy storage device, and a series of at least three switches (IPM) using switch/level boost-type PWM rectification. The burst test is repeated until a full rotation of magnetic angles are tested and recorded with the Signal Processor. Rotor impedance versus magnetic angle of the full rotation is verified in order to check for failure, and broken rotor bar defect is determined when a shift in measured stator's impedance/admittance level for any of the given magnetic angles is identified by the Signal Processor.

Claims12

Dependent claims

A method for magnetic/impedance burst testing of electric motors comprising:

providing a portable tester that provides a Signal Processor, a single-phase power source VAC, an AC to DC boost converter connected to the power source, at least one energy storage device connected to the AC to DC boost converter, a pulse width modulated drive (PWM) module connected to the at least one energy storage device, and a series of at least three switches (IPM) using switch/level boost-type PWM rectification, the IPM connected to both the 3 legs of the large electric motor and the PWM drive, the method comprising:
programming the PWM drive with a desired duration of output burst with the Signal Processor;
programming the PWM drive with an initial magnetic test angle with the Signal Processor;
programming the PWM drive with a test frequency for magnetic angle reversals with the Signal Processor;
programming the Programmable Gain Amplifier with the Signal Processor to optimize the signal gain in order to prevent voltage and current signal clipping;
and
controlling the PWM drive module with the Signal Processor to control the amplitude, magnetic angle and reversal frequency applied to the electric motor (ACIM).

4 more elements

A system for magnetic/impedance burst testing of electric motors to determine broken rotor bar defect, the system being encased in a portable tester and comprising:

a Signal Processor;
a single-phase power source VAC;
an AC to DC boost converter connected to the power source;
at least one energy storage device connected to the AC to DC boost converter;
a Pulse Width Modulated drive module (PWM) connected to the at least one energy storage device;
and
a series of at least three switches (IPM) using switch/level boost-type PWM rectification, the IPM connected to both the 3 legs of the large electric motor and the PWM drive, wherein
the PWM is programmed with a desired duration of output burst by the Signal Processor;
the PWM is programmed with an initial magnetic test angle by the Signal Processor, the PWM is programmed with a test frequency for magnetic angle reversals by the Signal Processor;
the programmable Gain Amplifier is programmed by the Signal Processor to optimize the signal gain in order to prevent voltage and current signal clipping;
and
the PWM is controlled by the Signal Processor to control the amplitude, magnetic angle and reversal frequency applied to the electric motor (ACIM).

9 more elements

Dependencies are inferred from the claim text.

Method for magnetic burst testing of large electric motors with portable tester powered by a domestic wall outlet

Life of this patent

Method for magnetic burst testing of large electric motors with portable tester powered by a domestic wall outlet

Life of this patent

Abstract

Claims12